4113 lines
110 KiB
C
4113 lines
110 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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// SPI init/core code
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//
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// Copyright (C) 2005 David Brownell
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// Copyright (C) 2008 Secret Lab Technologies Ltd.
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/init.h>
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#include <linux/cache.h>
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#include <linux/dma-mapping.h>
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#include <linux/dmaengine.h>
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#include <linux/mutex.h>
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#include <linux/of_device.h>
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#include <linux/of_irq.h>
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#include <linux/clk/clk-conf.h>
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#include <linux/slab.h>
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#include <linux/mod_devicetable.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/spi-mem.h>
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#include <linux/of_gpio.h>
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#include <linux/gpio/consumer.h>
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#include <linux/pm_runtime.h>
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#include <linux/pm_domain.h>
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#include <linux/property.h>
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#include <linux/export.h>
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#include <linux/sched/rt.h>
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#include <uapi/linux/sched/types.h>
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#include <linux/delay.h>
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#include <linux/kthread.h>
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#include <linux/ioport.h>
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#include <linux/acpi.h>
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#include <linux/highmem.h>
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#include <linux/idr.h>
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#include <linux/platform_data/x86/apple.h>
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#define CREATE_TRACE_POINTS
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#include <trace/events/spi.h>
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EXPORT_TRACEPOINT_SYMBOL(spi_transfer_start);
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EXPORT_TRACEPOINT_SYMBOL(spi_transfer_stop);
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#include "internals.h"
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static DEFINE_IDR(spi_master_idr);
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static void spidev_release(struct device *dev)
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{
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struct spi_device *spi = to_spi_device(dev);
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/* spi controllers may cleanup for released devices */
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if (spi->controller->cleanup)
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spi->controller->cleanup(spi);
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spi_controller_put(spi->controller);
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kfree(spi->driver_override);
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kfree(spi);
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}
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static ssize_t
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modalias_show(struct device *dev, struct device_attribute *a, char *buf)
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{
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const struct spi_device *spi = to_spi_device(dev);
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int len;
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len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
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if (len != -ENODEV)
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return len;
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return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias);
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}
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static DEVICE_ATTR_RO(modalias);
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static ssize_t driver_override_store(struct device *dev,
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struct device_attribute *a,
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const char *buf, size_t count)
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{
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struct spi_device *spi = to_spi_device(dev);
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const char *end = memchr(buf, '\n', count);
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const size_t len = end ? end - buf : count;
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const char *driver_override, *old;
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/* We need to keep extra room for a newline when displaying value */
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if (len >= (PAGE_SIZE - 1))
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return -EINVAL;
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driver_override = kstrndup(buf, len, GFP_KERNEL);
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if (!driver_override)
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return -ENOMEM;
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device_lock(dev);
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old = spi->driver_override;
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if (len) {
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spi->driver_override = driver_override;
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} else {
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/* Empty string, disable driver override */
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spi->driver_override = NULL;
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kfree(driver_override);
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}
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device_unlock(dev);
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kfree(old);
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return count;
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}
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static ssize_t driver_override_show(struct device *dev,
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struct device_attribute *a, char *buf)
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{
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const struct spi_device *spi = to_spi_device(dev);
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ssize_t len;
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device_lock(dev);
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len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : "");
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device_unlock(dev);
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return len;
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}
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static DEVICE_ATTR_RW(driver_override);
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#define SPI_STATISTICS_ATTRS(field, file) \
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static ssize_t spi_controller_##field##_show(struct device *dev, \
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struct device_attribute *attr, \
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char *buf) \
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{ \
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struct spi_controller *ctlr = container_of(dev, \
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struct spi_controller, dev); \
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return spi_statistics_##field##_show(&ctlr->statistics, buf); \
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} \
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static struct device_attribute dev_attr_spi_controller_##field = { \
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.attr = { .name = file, .mode = 0444 }, \
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.show = spi_controller_##field##_show, \
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}; \
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static ssize_t spi_device_##field##_show(struct device *dev, \
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struct device_attribute *attr, \
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char *buf) \
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{ \
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struct spi_device *spi = to_spi_device(dev); \
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return spi_statistics_##field##_show(&spi->statistics, buf); \
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} \
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static struct device_attribute dev_attr_spi_device_##field = { \
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.attr = { .name = file, .mode = 0444 }, \
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.show = spi_device_##field##_show, \
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}
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#define SPI_STATISTICS_SHOW_NAME(name, file, field, format_string) \
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static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \
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char *buf) \
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{ \
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unsigned long flags; \
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ssize_t len; \
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spin_lock_irqsave(&stat->lock, flags); \
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len = sprintf(buf, format_string, stat->field); \
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spin_unlock_irqrestore(&stat->lock, flags); \
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return len; \
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} \
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SPI_STATISTICS_ATTRS(name, file)
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#define SPI_STATISTICS_SHOW(field, format_string) \
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SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \
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field, format_string)
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SPI_STATISTICS_SHOW(messages, "%lu");
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SPI_STATISTICS_SHOW(transfers, "%lu");
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SPI_STATISTICS_SHOW(errors, "%lu");
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SPI_STATISTICS_SHOW(timedout, "%lu");
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SPI_STATISTICS_SHOW(spi_sync, "%lu");
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SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu");
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SPI_STATISTICS_SHOW(spi_async, "%lu");
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SPI_STATISTICS_SHOW(bytes, "%llu");
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SPI_STATISTICS_SHOW(bytes_rx, "%llu");
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SPI_STATISTICS_SHOW(bytes_tx, "%llu");
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#define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \
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SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \
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"transfer_bytes_histo_" number, \
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transfer_bytes_histo[index], "%lu")
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(3, "8-15");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(4, "16-31");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(5, "32-63");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(6, "64-127");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(7, "128-255");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(8, "256-511");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(9, "512-1023");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(10, "1024-2047");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(11, "2048-4095");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(12, "4096-8191");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(13, "8192-16383");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535");
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SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+");
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SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu");
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static struct attribute *spi_dev_attrs[] = {
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&dev_attr_modalias.attr,
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&dev_attr_driver_override.attr,
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NULL,
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};
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static const struct attribute_group spi_dev_group = {
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.attrs = spi_dev_attrs,
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};
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static struct attribute *spi_device_statistics_attrs[] = {
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&dev_attr_spi_device_messages.attr,
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&dev_attr_spi_device_transfers.attr,
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&dev_attr_spi_device_errors.attr,
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&dev_attr_spi_device_timedout.attr,
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&dev_attr_spi_device_spi_sync.attr,
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&dev_attr_spi_device_spi_sync_immediate.attr,
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&dev_attr_spi_device_spi_async.attr,
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&dev_attr_spi_device_bytes.attr,
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&dev_attr_spi_device_bytes_rx.attr,
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&dev_attr_spi_device_bytes_tx.attr,
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&dev_attr_spi_device_transfer_bytes_histo0.attr,
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&dev_attr_spi_device_transfer_bytes_histo1.attr,
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&dev_attr_spi_device_transfer_bytes_histo2.attr,
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&dev_attr_spi_device_transfer_bytes_histo3.attr,
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&dev_attr_spi_device_transfer_bytes_histo4.attr,
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&dev_attr_spi_device_transfer_bytes_histo5.attr,
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&dev_attr_spi_device_transfer_bytes_histo6.attr,
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&dev_attr_spi_device_transfer_bytes_histo7.attr,
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&dev_attr_spi_device_transfer_bytes_histo8.attr,
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&dev_attr_spi_device_transfer_bytes_histo9.attr,
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&dev_attr_spi_device_transfer_bytes_histo10.attr,
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&dev_attr_spi_device_transfer_bytes_histo11.attr,
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&dev_attr_spi_device_transfer_bytes_histo12.attr,
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&dev_attr_spi_device_transfer_bytes_histo13.attr,
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&dev_attr_spi_device_transfer_bytes_histo14.attr,
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&dev_attr_spi_device_transfer_bytes_histo15.attr,
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&dev_attr_spi_device_transfer_bytes_histo16.attr,
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&dev_attr_spi_device_transfers_split_maxsize.attr,
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NULL,
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};
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static const struct attribute_group spi_device_statistics_group = {
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.name = "statistics",
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.attrs = spi_device_statistics_attrs,
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};
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static const struct attribute_group *spi_dev_groups[] = {
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&spi_dev_group,
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&spi_device_statistics_group,
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NULL,
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};
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static struct attribute *spi_controller_statistics_attrs[] = {
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&dev_attr_spi_controller_messages.attr,
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&dev_attr_spi_controller_transfers.attr,
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&dev_attr_spi_controller_errors.attr,
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&dev_attr_spi_controller_timedout.attr,
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&dev_attr_spi_controller_spi_sync.attr,
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&dev_attr_spi_controller_spi_sync_immediate.attr,
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&dev_attr_spi_controller_spi_async.attr,
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&dev_attr_spi_controller_bytes.attr,
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&dev_attr_spi_controller_bytes_rx.attr,
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&dev_attr_spi_controller_bytes_tx.attr,
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&dev_attr_spi_controller_transfer_bytes_histo0.attr,
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&dev_attr_spi_controller_transfer_bytes_histo1.attr,
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&dev_attr_spi_controller_transfer_bytes_histo2.attr,
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&dev_attr_spi_controller_transfer_bytes_histo3.attr,
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&dev_attr_spi_controller_transfer_bytes_histo4.attr,
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&dev_attr_spi_controller_transfer_bytes_histo5.attr,
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&dev_attr_spi_controller_transfer_bytes_histo6.attr,
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&dev_attr_spi_controller_transfer_bytes_histo7.attr,
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&dev_attr_spi_controller_transfer_bytes_histo8.attr,
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&dev_attr_spi_controller_transfer_bytes_histo9.attr,
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&dev_attr_spi_controller_transfer_bytes_histo10.attr,
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&dev_attr_spi_controller_transfer_bytes_histo11.attr,
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&dev_attr_spi_controller_transfer_bytes_histo12.attr,
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&dev_attr_spi_controller_transfer_bytes_histo13.attr,
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&dev_attr_spi_controller_transfer_bytes_histo14.attr,
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&dev_attr_spi_controller_transfer_bytes_histo15.attr,
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&dev_attr_spi_controller_transfer_bytes_histo16.attr,
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&dev_attr_spi_controller_transfers_split_maxsize.attr,
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NULL,
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};
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static const struct attribute_group spi_controller_statistics_group = {
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.name = "statistics",
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.attrs = spi_controller_statistics_attrs,
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};
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static const struct attribute_group *spi_master_groups[] = {
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&spi_controller_statistics_group,
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NULL,
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};
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void spi_statistics_add_transfer_stats(struct spi_statistics *stats,
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struct spi_transfer *xfer,
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struct spi_controller *ctlr)
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{
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unsigned long flags;
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int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1;
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if (l2len < 0)
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l2len = 0;
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spin_lock_irqsave(&stats->lock, flags);
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stats->transfers++;
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stats->transfer_bytes_histo[l2len]++;
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stats->bytes += xfer->len;
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if ((xfer->tx_buf) &&
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(xfer->tx_buf != ctlr->dummy_tx))
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stats->bytes_tx += xfer->len;
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if ((xfer->rx_buf) &&
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(xfer->rx_buf != ctlr->dummy_rx))
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stats->bytes_rx += xfer->len;
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spin_unlock_irqrestore(&stats->lock, flags);
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}
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EXPORT_SYMBOL_GPL(spi_statistics_add_transfer_stats);
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/* modalias support makes "modprobe $MODALIAS" new-style hotplug work,
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* and the sysfs version makes coldplug work too.
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*/
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static const struct spi_device_id *spi_match_id(const struct spi_device_id *id,
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const struct spi_device *sdev)
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{
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while (id->name[0]) {
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if (!strcmp(sdev->modalias, id->name))
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return id;
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id++;
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}
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return NULL;
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}
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const struct spi_device_id *spi_get_device_id(const struct spi_device *sdev)
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{
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const struct spi_driver *sdrv = to_spi_driver(sdev->dev.driver);
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return spi_match_id(sdrv->id_table, sdev);
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}
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EXPORT_SYMBOL_GPL(spi_get_device_id);
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static int spi_match_device(struct device *dev, struct device_driver *drv)
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{
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const struct spi_device *spi = to_spi_device(dev);
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const struct spi_driver *sdrv = to_spi_driver(drv);
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/* Check override first, and if set, only use the named driver */
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if (spi->driver_override)
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return strcmp(spi->driver_override, drv->name) == 0;
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/* Attempt an OF style match */
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if (of_driver_match_device(dev, drv))
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return 1;
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/* Then try ACPI */
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if (acpi_driver_match_device(dev, drv))
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return 1;
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if (sdrv->id_table)
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return !!spi_match_id(sdrv->id_table, spi);
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return strcmp(spi->modalias, drv->name) == 0;
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}
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static int spi_uevent(struct device *dev, struct kobj_uevent_env *env)
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{
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const struct spi_device *spi = to_spi_device(dev);
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int rc;
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rc = acpi_device_uevent_modalias(dev, env);
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if (rc != -ENODEV)
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return rc;
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return add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias);
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}
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struct bus_type spi_bus_type = {
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.name = "spi",
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.dev_groups = spi_dev_groups,
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.match = spi_match_device,
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.uevent = spi_uevent,
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};
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EXPORT_SYMBOL_GPL(spi_bus_type);
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static int spi_drv_probe(struct device *dev)
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{
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const struct spi_driver *sdrv = to_spi_driver(dev->driver);
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struct spi_device *spi = to_spi_device(dev);
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int ret;
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ret = of_clk_set_defaults(dev->of_node, false);
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if (ret)
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return ret;
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if (dev->of_node) {
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spi->irq = of_irq_get(dev->of_node, 0);
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if (spi->irq == -EPROBE_DEFER)
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return -EPROBE_DEFER;
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if (spi->irq < 0)
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spi->irq = 0;
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}
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ret = dev_pm_domain_attach(dev, true);
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if (ret)
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return ret;
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ret = sdrv->probe(spi);
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if (ret)
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dev_pm_domain_detach(dev, true);
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return ret;
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}
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static int spi_drv_remove(struct device *dev)
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{
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const struct spi_driver *sdrv = to_spi_driver(dev->driver);
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int ret;
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ret = sdrv->remove(to_spi_device(dev));
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dev_pm_domain_detach(dev, true);
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return ret;
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}
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static void spi_drv_shutdown(struct device *dev)
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{
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const struct spi_driver *sdrv = to_spi_driver(dev->driver);
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sdrv->shutdown(to_spi_device(dev));
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}
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/**
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* __spi_register_driver - register a SPI driver
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* @owner: owner module of the driver to register
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* @sdrv: the driver to register
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* Context: can sleep
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*
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* Return: zero on success, else a negative error code.
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*/
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int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
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{
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sdrv->driver.owner = owner;
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sdrv->driver.bus = &spi_bus_type;
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if (sdrv->probe)
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sdrv->driver.probe = spi_drv_probe;
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if (sdrv->remove)
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sdrv->driver.remove = spi_drv_remove;
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if (sdrv->shutdown)
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sdrv->driver.shutdown = spi_drv_shutdown;
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return driver_register(&sdrv->driver);
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}
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EXPORT_SYMBOL_GPL(__spi_register_driver);
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/*-------------------------------------------------------------------------*/
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/* SPI devices should normally not be created by SPI device drivers; that
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* would make them board-specific. Similarly with SPI controller drivers.
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* Device registration normally goes into like arch/.../mach.../board-YYY.c
|
|
* with other readonly (flashable) information about mainboard devices.
|
|
*/
|
|
|
|
struct boardinfo {
|
|
struct list_head list;
|
|
struct spi_board_info board_info;
|
|
};
|
|
|
|
static LIST_HEAD(board_list);
|
|
static LIST_HEAD(spi_controller_list);
|
|
|
|
/*
|
|
* Used to protect add/del operation for board_info list and
|
|
* spi_controller list, and their matching process
|
|
* also used to protect object of type struct idr
|
|
*/
|
|
static DEFINE_MUTEX(board_lock);
|
|
|
|
/**
|
|
* spi_alloc_device - Allocate a new SPI device
|
|
* @ctlr: Controller to which device is connected
|
|
* Context: can sleep
|
|
*
|
|
* Allows a driver to allocate and initialize a spi_device without
|
|
* registering it immediately. This allows a driver to directly
|
|
* fill the spi_device with device parameters before calling
|
|
* spi_add_device() on it.
|
|
*
|
|
* Caller is responsible to call spi_add_device() on the returned
|
|
* spi_device structure to add it to the SPI controller. If the caller
|
|
* needs to discard the spi_device without adding it, then it should
|
|
* call spi_dev_put() on it.
|
|
*
|
|
* Return: a pointer to the new device, or NULL.
|
|
*/
|
|
struct spi_device *spi_alloc_device(struct spi_controller *ctlr)
|
|
{
|
|
struct spi_device *spi;
|
|
|
|
if (!spi_controller_get(ctlr))
|
|
return NULL;
|
|
|
|
spi = kzalloc(sizeof(*spi), GFP_KERNEL);
|
|
if (!spi) {
|
|
spi_controller_put(ctlr);
|
|
return NULL;
|
|
}
|
|
|
|
spi->master = spi->controller = ctlr;
|
|
spi->dev.parent = &ctlr->dev;
|
|
spi->dev.bus = &spi_bus_type;
|
|
spi->dev.release = spidev_release;
|
|
spi->cs_gpio = -ENOENT;
|
|
|
|
spin_lock_init(&spi->statistics.lock);
|
|
|
|
device_initialize(&spi->dev);
|
|
return spi;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_alloc_device);
|
|
|
|
static void spi_dev_set_name(struct spi_device *spi)
|
|
{
|
|
struct acpi_device *adev = ACPI_COMPANION(&spi->dev);
|
|
|
|
if (adev) {
|
|
dev_set_name(&spi->dev, "spi-%s", acpi_dev_name(adev));
|
|
return;
|
|
}
|
|
|
|
dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
|
|
spi->chip_select);
|
|
}
|
|
|
|
static int spi_dev_check(struct device *dev, void *data)
|
|
{
|
|
struct spi_device *spi = to_spi_device(dev);
|
|
struct spi_device *new_spi = data;
|
|
|
|
if (spi->controller == new_spi->controller &&
|
|
spi->chip_select == new_spi->chip_select)
|
|
return -EBUSY;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* spi_add_device - Add spi_device allocated with spi_alloc_device
|
|
* @spi: spi_device to register
|
|
*
|
|
* Companion function to spi_alloc_device. Devices allocated with
|
|
* spi_alloc_device can be added onto the spi bus with this function.
|
|
*
|
|
* Return: 0 on success; negative errno on failure
|
|
*/
|
|
int spi_add_device(struct spi_device *spi)
|
|
{
|
|
static DEFINE_MUTEX(spi_add_lock);
|
|
struct spi_controller *ctlr = spi->controller;
|
|
struct device *dev = ctlr->dev.parent;
|
|
int status;
|
|
|
|
/* Chipselects are numbered 0..max; validate. */
|
|
if (spi->chip_select >= ctlr->num_chipselect) {
|
|
dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
|
|
ctlr->num_chipselect);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Set the bus ID string */
|
|
spi_dev_set_name(spi);
|
|
|
|
/* We need to make sure there's no other device with this
|
|
* chipselect **BEFORE** we call setup(), else we'll trash
|
|
* its configuration. Lock against concurrent add() calls.
|
|
*/
|
|
mutex_lock(&spi_add_lock);
|
|
|
|
status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
|
|
if (status) {
|
|
dev_err(dev, "chipselect %d already in use\n",
|
|
spi->chip_select);
|
|
goto done;
|
|
}
|
|
|
|
/* Descriptors take precedence */
|
|
if (ctlr->cs_gpiods)
|
|
spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
|
|
else if (ctlr->cs_gpios)
|
|
spi->cs_gpio = ctlr->cs_gpios[spi->chip_select];
|
|
|
|
/* Drivers may modify this initial i/o setup, but will
|
|
* normally rely on the device being setup. Devices
|
|
* using SPI_CS_HIGH can't coexist well otherwise...
|
|
*/
|
|
status = spi_setup(spi);
|
|
if (status < 0) {
|
|
dev_err(dev, "can't setup %s, status %d\n",
|
|
dev_name(&spi->dev), status);
|
|
goto done;
|
|
}
|
|
|
|
/* Device may be bound to an active driver when this returns */
|
|
status = device_add(&spi->dev);
|
|
if (status < 0)
|
|
dev_err(dev, "can't add %s, status %d\n",
|
|
dev_name(&spi->dev), status);
|
|
else
|
|
dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev));
|
|
|
|
done:
|
|
mutex_unlock(&spi_add_lock);
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_add_device);
|
|
|
|
/**
|
|
* spi_new_device - instantiate one new SPI device
|
|
* @ctlr: Controller to which device is connected
|
|
* @chip: Describes the SPI device
|
|
* Context: can sleep
|
|
*
|
|
* On typical mainboards, this is purely internal; and it's not needed
|
|
* after board init creates the hard-wired devices. Some development
|
|
* platforms may not be able to use spi_register_board_info though, and
|
|
* this is exported so that for example a USB or parport based adapter
|
|
* driver could add devices (which it would learn about out-of-band).
|
|
*
|
|
* Return: the new device, or NULL.
|
|
*/
|
|
struct spi_device *spi_new_device(struct spi_controller *ctlr,
|
|
struct spi_board_info *chip)
|
|
{
|
|
struct spi_device *proxy;
|
|
int status;
|
|
|
|
/* NOTE: caller did any chip->bus_num checks necessary.
|
|
*
|
|
* Also, unless we change the return value convention to use
|
|
* error-or-pointer (not NULL-or-pointer), troubleshootability
|
|
* suggests syslogged diagnostics are best here (ugh).
|
|
*/
|
|
|
|
proxy = spi_alloc_device(ctlr);
|
|
if (!proxy)
|
|
return NULL;
|
|
|
|
WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
|
|
|
|
proxy->chip_select = chip->chip_select;
|
|
proxy->max_speed_hz = chip->max_speed_hz;
|
|
proxy->mode = chip->mode;
|
|
proxy->irq = chip->irq;
|
|
strlcpy(proxy->modalias, chip->modalias, sizeof(proxy->modalias));
|
|
proxy->dev.platform_data = (void *) chip->platform_data;
|
|
proxy->controller_data = chip->controller_data;
|
|
proxy->controller_state = NULL;
|
|
|
|
if (chip->properties) {
|
|
status = device_add_properties(&proxy->dev, chip->properties);
|
|
if (status) {
|
|
dev_err(&ctlr->dev,
|
|
"failed to add properties to '%s': %d\n",
|
|
chip->modalias, status);
|
|
goto err_dev_put;
|
|
}
|
|
}
|
|
|
|
status = spi_add_device(proxy);
|
|
if (status < 0)
|
|
goto err_remove_props;
|
|
|
|
return proxy;
|
|
|
|
err_remove_props:
|
|
if (chip->properties)
|
|
device_remove_properties(&proxy->dev);
|
|
err_dev_put:
|
|
spi_dev_put(proxy);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_new_device);
|
|
|
|
/**
|
|
* spi_unregister_device - unregister a single SPI device
|
|
* @spi: spi_device to unregister
|
|
*
|
|
* Start making the passed SPI device vanish. Normally this would be handled
|
|
* by spi_unregister_controller().
|
|
*/
|
|
void spi_unregister_device(struct spi_device *spi)
|
|
{
|
|
if (!spi)
|
|
return;
|
|
|
|
if (spi->dev.of_node) {
|
|
of_node_clear_flag(spi->dev.of_node, OF_POPULATED);
|
|
of_node_put(spi->dev.of_node);
|
|
}
|
|
if (ACPI_COMPANION(&spi->dev))
|
|
acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev));
|
|
device_unregister(&spi->dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_unregister_device);
|
|
|
|
static void spi_match_controller_to_boardinfo(struct spi_controller *ctlr,
|
|
struct spi_board_info *bi)
|
|
{
|
|
struct spi_device *dev;
|
|
|
|
if (ctlr->bus_num != bi->bus_num)
|
|
return;
|
|
|
|
dev = spi_new_device(ctlr, bi);
|
|
if (!dev)
|
|
dev_err(ctlr->dev.parent, "can't create new device for %s\n",
|
|
bi->modalias);
|
|
}
|
|
|
|
/**
|
|
* spi_register_board_info - register SPI devices for a given board
|
|
* @info: array of chip descriptors
|
|
* @n: how many descriptors are provided
|
|
* Context: can sleep
|
|
*
|
|
* Board-specific early init code calls this (probably during arch_initcall)
|
|
* with segments of the SPI device table. Any device nodes are created later,
|
|
* after the relevant parent SPI controller (bus_num) is defined. We keep
|
|
* this table of devices forever, so that reloading a controller driver will
|
|
* not make Linux forget about these hard-wired devices.
|
|
*
|
|
* Other code can also call this, e.g. a particular add-on board might provide
|
|
* SPI devices through its expansion connector, so code initializing that board
|
|
* would naturally declare its SPI devices.
|
|
*
|
|
* The board info passed can safely be __initdata ... but be careful of
|
|
* any embedded pointers (platform_data, etc), they're copied as-is.
|
|
* Device properties are deep-copied though.
|
|
*
|
|
* Return: zero on success, else a negative error code.
|
|
*/
|
|
int spi_register_board_info(struct spi_board_info const *info, unsigned n)
|
|
{
|
|
struct boardinfo *bi;
|
|
int i;
|
|
|
|
if (!n)
|
|
return 0;
|
|
|
|
bi = kcalloc(n, sizeof(*bi), GFP_KERNEL);
|
|
if (!bi)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; i < n; i++, bi++, info++) {
|
|
struct spi_controller *ctlr;
|
|
|
|
memcpy(&bi->board_info, info, sizeof(*info));
|
|
if (info->properties) {
|
|
bi->board_info.properties =
|
|
property_entries_dup(info->properties);
|
|
if (IS_ERR(bi->board_info.properties))
|
|
return PTR_ERR(bi->board_info.properties);
|
|
}
|
|
|
|
mutex_lock(&board_lock);
|
|
list_add_tail(&bi->list, &board_list);
|
|
list_for_each_entry(ctlr, &spi_controller_list, list)
|
|
spi_match_controller_to_boardinfo(ctlr,
|
|
&bi->board_info);
|
|
mutex_unlock(&board_lock);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
static void spi_set_cs(struct spi_device *spi, bool enable)
|
|
{
|
|
bool enable1 = enable;
|
|
|
|
if (!spi->controller->set_cs_timing) {
|
|
if (enable1)
|
|
spi_delay_exec(&spi->controller->cs_setup, NULL);
|
|
else
|
|
spi_delay_exec(&spi->controller->cs_hold, NULL);
|
|
}
|
|
|
|
if (spi->mode & SPI_CS_HIGH)
|
|
enable = !enable;
|
|
|
|
if (spi->cs_gpiod || gpio_is_valid(spi->cs_gpio)) {
|
|
/*
|
|
* Honour the SPI_NO_CS flag and invert the enable line, as
|
|
* active low is default for SPI. Execution paths that handle
|
|
* polarity inversion in gpiolib (such as device tree) will
|
|
* enforce active high using the SPI_CS_HIGH resulting in a
|
|
* double inversion through the code above.
|
|
*/
|
|
if (!(spi->mode & SPI_NO_CS)) {
|
|
if (spi->cs_gpiod)
|
|
gpiod_set_value_cansleep(spi->cs_gpiod,
|
|
!enable);
|
|
else
|
|
gpio_set_value_cansleep(spi->cs_gpio, !enable);
|
|
}
|
|
/* Some SPI masters need both GPIO CS & slave_select */
|
|
if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
|
|
spi->controller->set_cs)
|
|
spi->controller->set_cs(spi, !enable);
|
|
} else if (spi->controller->set_cs) {
|
|
spi->controller->set_cs(spi, !enable);
|
|
}
|
|
|
|
if (!spi->controller->set_cs_timing) {
|
|
if (!enable1)
|
|
spi_delay_exec(&spi->controller->cs_inactive, NULL);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_HAS_DMA
|
|
int spi_map_buf(struct spi_controller *ctlr, struct device *dev,
|
|
struct sg_table *sgt, void *buf, size_t len,
|
|
enum dma_data_direction dir)
|
|
{
|
|
const bool vmalloced_buf = is_vmalloc_addr(buf);
|
|
unsigned int max_seg_size = dma_get_max_seg_size(dev);
|
|
#ifdef CONFIG_HIGHMEM
|
|
const bool kmap_buf = ((unsigned long)buf >= PKMAP_BASE &&
|
|
(unsigned long)buf < (PKMAP_BASE +
|
|
(LAST_PKMAP * PAGE_SIZE)));
|
|
#else
|
|
const bool kmap_buf = false;
|
|
#endif
|
|
int desc_len;
|
|
int sgs;
|
|
struct page *vm_page;
|
|
struct scatterlist *sg;
|
|
void *sg_buf;
|
|
size_t min;
|
|
int i, ret;
|
|
|
|
if (vmalloced_buf || kmap_buf) {
|
|
desc_len = min_t(int, max_seg_size, PAGE_SIZE);
|
|
sgs = DIV_ROUND_UP(len + offset_in_page(buf), desc_len);
|
|
} else if (virt_addr_valid(buf)) {
|
|
desc_len = min_t(int, max_seg_size, ctlr->max_dma_len);
|
|
sgs = DIV_ROUND_UP(len, desc_len);
|
|
} else {
|
|
return -EINVAL;
|
|
}
|
|
|
|
ret = sg_alloc_table(sgt, sgs, GFP_KERNEL);
|
|
if (ret != 0)
|
|
return ret;
|
|
|
|
sg = &sgt->sgl[0];
|
|
for (i = 0; i < sgs; i++) {
|
|
|
|
if (vmalloced_buf || kmap_buf) {
|
|
/*
|
|
* Next scatterlist entry size is the minimum between
|
|
* the desc_len and the remaining buffer length that
|
|
* fits in a page.
|
|
*/
|
|
min = min_t(size_t, desc_len,
|
|
min_t(size_t, len,
|
|
PAGE_SIZE - offset_in_page(buf)));
|
|
if (vmalloced_buf)
|
|
vm_page = vmalloc_to_page(buf);
|
|
else
|
|
vm_page = kmap_to_page(buf);
|
|
if (!vm_page) {
|
|
sg_free_table(sgt);
|
|
return -ENOMEM;
|
|
}
|
|
sg_set_page(sg, vm_page,
|
|
min, offset_in_page(buf));
|
|
} else {
|
|
min = min_t(size_t, len, desc_len);
|
|
sg_buf = buf;
|
|
sg_set_buf(sg, sg_buf, min);
|
|
}
|
|
|
|
buf += min;
|
|
len -= min;
|
|
sg = sg_next(sg);
|
|
}
|
|
|
|
ret = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
|
|
if (!ret)
|
|
ret = -ENOMEM;
|
|
if (ret < 0) {
|
|
sg_free_table(sgt);
|
|
return ret;
|
|
}
|
|
|
|
sgt->nents = ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void spi_unmap_buf(struct spi_controller *ctlr, struct device *dev,
|
|
struct sg_table *sgt, enum dma_data_direction dir)
|
|
{
|
|
if (sgt->orig_nents) {
|
|
dma_unmap_sg(dev, sgt->sgl, sgt->orig_nents, dir);
|
|
sg_free_table(sgt);
|
|
}
|
|
}
|
|
|
|
static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
|
|
{
|
|
struct device *tx_dev, *rx_dev;
|
|
struct spi_transfer *xfer;
|
|
int ret;
|
|
|
|
if (!ctlr->can_dma)
|
|
return 0;
|
|
|
|
if (ctlr->dma_tx)
|
|
tx_dev = ctlr->dma_tx->device->dev;
|
|
else
|
|
tx_dev = ctlr->dev.parent;
|
|
|
|
if (ctlr->dma_rx)
|
|
rx_dev = ctlr->dma_rx->device->dev;
|
|
else
|
|
rx_dev = ctlr->dev.parent;
|
|
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
|
|
if (!ctlr->can_dma(ctlr, msg->spi, xfer))
|
|
continue;
|
|
|
|
if (xfer->tx_buf != NULL) {
|
|
ret = spi_map_buf(ctlr, tx_dev, &xfer->tx_sg,
|
|
(void *)xfer->tx_buf, xfer->len,
|
|
DMA_TO_DEVICE);
|
|
if (ret != 0)
|
|
return ret;
|
|
}
|
|
|
|
if (xfer->rx_buf != NULL) {
|
|
ret = spi_map_buf(ctlr, rx_dev, &xfer->rx_sg,
|
|
xfer->rx_buf, xfer->len,
|
|
DMA_FROM_DEVICE);
|
|
if (ret != 0) {
|
|
spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg,
|
|
DMA_TO_DEVICE);
|
|
return ret;
|
|
}
|
|
}
|
|
}
|
|
|
|
ctlr->cur_msg_mapped = true;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __spi_unmap_msg(struct spi_controller *ctlr, struct spi_message *msg)
|
|
{
|
|
struct spi_transfer *xfer;
|
|
struct device *tx_dev, *rx_dev;
|
|
|
|
if (!ctlr->cur_msg_mapped || !ctlr->can_dma)
|
|
return 0;
|
|
|
|
if (ctlr->dma_tx)
|
|
tx_dev = ctlr->dma_tx->device->dev;
|
|
else
|
|
tx_dev = ctlr->dev.parent;
|
|
|
|
if (ctlr->dma_rx)
|
|
rx_dev = ctlr->dma_rx->device->dev;
|
|
else
|
|
rx_dev = ctlr->dev.parent;
|
|
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
|
|
if (!ctlr->can_dma(ctlr, msg->spi, xfer))
|
|
continue;
|
|
|
|
spi_unmap_buf(ctlr, rx_dev, &xfer->rx_sg, DMA_FROM_DEVICE);
|
|
spi_unmap_buf(ctlr, tx_dev, &xfer->tx_sg, DMA_TO_DEVICE);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
#else /* !CONFIG_HAS_DMA */
|
|
static inline int __spi_map_msg(struct spi_controller *ctlr,
|
|
struct spi_message *msg)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline int __spi_unmap_msg(struct spi_controller *ctlr,
|
|
struct spi_message *msg)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* !CONFIG_HAS_DMA */
|
|
|
|
static inline int spi_unmap_msg(struct spi_controller *ctlr,
|
|
struct spi_message *msg)
|
|
{
|
|
struct spi_transfer *xfer;
|
|
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
|
|
/*
|
|
* Restore the original value of tx_buf or rx_buf if they are
|
|
* NULL.
|
|
*/
|
|
if (xfer->tx_buf == ctlr->dummy_tx)
|
|
xfer->tx_buf = NULL;
|
|
if (xfer->rx_buf == ctlr->dummy_rx)
|
|
xfer->rx_buf = NULL;
|
|
}
|
|
|
|
return __spi_unmap_msg(ctlr, msg);
|
|
}
|
|
|
|
static int spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg)
|
|
{
|
|
struct spi_transfer *xfer;
|
|
void *tmp;
|
|
unsigned int max_tx, max_rx;
|
|
|
|
if (ctlr->flags & (SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX)) {
|
|
max_tx = 0;
|
|
max_rx = 0;
|
|
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
|
|
if ((ctlr->flags & SPI_CONTROLLER_MUST_TX) &&
|
|
!xfer->tx_buf)
|
|
max_tx = max(xfer->len, max_tx);
|
|
if ((ctlr->flags & SPI_CONTROLLER_MUST_RX) &&
|
|
!xfer->rx_buf)
|
|
max_rx = max(xfer->len, max_rx);
|
|
}
|
|
|
|
if (max_tx) {
|
|
tmp = krealloc(ctlr->dummy_tx, max_tx,
|
|
GFP_KERNEL | GFP_DMA);
|
|
if (!tmp)
|
|
return -ENOMEM;
|
|
ctlr->dummy_tx = tmp;
|
|
memset(tmp, 0, max_tx);
|
|
}
|
|
|
|
if (max_rx) {
|
|
tmp = krealloc(ctlr->dummy_rx, max_rx,
|
|
GFP_KERNEL | GFP_DMA);
|
|
if (!tmp)
|
|
return -ENOMEM;
|
|
ctlr->dummy_rx = tmp;
|
|
}
|
|
|
|
if (max_tx || max_rx) {
|
|
list_for_each_entry(xfer, &msg->transfers,
|
|
transfer_list) {
|
|
if (!xfer->len)
|
|
continue;
|
|
if (!xfer->tx_buf)
|
|
xfer->tx_buf = ctlr->dummy_tx;
|
|
if (!xfer->rx_buf)
|
|
xfer->rx_buf = ctlr->dummy_rx;
|
|
}
|
|
}
|
|
}
|
|
|
|
return __spi_map_msg(ctlr, msg);
|
|
}
|
|
|
|
static int spi_transfer_wait(struct spi_controller *ctlr,
|
|
struct spi_message *msg,
|
|
struct spi_transfer *xfer)
|
|
{
|
|
struct spi_statistics *statm = &ctlr->statistics;
|
|
struct spi_statistics *stats = &msg->spi->statistics;
|
|
unsigned long long ms = 1;
|
|
|
|
if (spi_controller_is_slave(ctlr)) {
|
|
if (wait_for_completion_interruptible(&ctlr->xfer_completion)) {
|
|
dev_dbg(&msg->spi->dev, "SPI transfer interrupted\n");
|
|
return -EINTR;
|
|
}
|
|
} else {
|
|
ms = 8LL * 1000LL * xfer->len;
|
|
do_div(ms, xfer->speed_hz);
|
|
ms += ms + 200; /* some tolerance */
|
|
|
|
if (ms > UINT_MAX)
|
|
ms = UINT_MAX;
|
|
|
|
ms = wait_for_completion_timeout(&ctlr->xfer_completion,
|
|
msecs_to_jiffies(ms));
|
|
|
|
if (ms == 0) {
|
|
SPI_STATISTICS_INCREMENT_FIELD(statm, timedout);
|
|
SPI_STATISTICS_INCREMENT_FIELD(stats, timedout);
|
|
dev_err(&msg->spi->dev,
|
|
"SPI transfer timed out\n");
|
|
return -ETIMEDOUT;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void _spi_transfer_delay_ns(u32 ns)
|
|
{
|
|
if (!ns)
|
|
return;
|
|
if (ns <= 1000) {
|
|
ndelay(ns);
|
|
} else {
|
|
u32 us = DIV_ROUND_UP(ns, 1000);
|
|
|
|
if (us <= 10)
|
|
udelay(us);
|
|
else
|
|
usleep_range(us, us + DIV_ROUND_UP(us, 10));
|
|
}
|
|
}
|
|
|
|
int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer)
|
|
{
|
|
u32 delay = _delay->value;
|
|
u32 unit = _delay->unit;
|
|
u32 hz;
|
|
|
|
if (!delay)
|
|
return 0;
|
|
|
|
switch (unit) {
|
|
case SPI_DELAY_UNIT_USECS:
|
|
delay *= 1000;
|
|
break;
|
|
case SPI_DELAY_UNIT_NSECS: /* nothing to do here */
|
|
break;
|
|
case SPI_DELAY_UNIT_SCK:
|
|
/* clock cycles need to be obtained from spi_transfer */
|
|
if (!xfer)
|
|
return -EINVAL;
|
|
/* if there is no effective speed know, then approximate
|
|
* by underestimating with half the requested hz
|
|
*/
|
|
hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2;
|
|
if (!hz)
|
|
return -EINVAL;
|
|
delay *= DIV_ROUND_UP(1000000000, hz);
|
|
break;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
return delay;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_delay_to_ns);
|
|
|
|
int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer)
|
|
{
|
|
int delay;
|
|
|
|
if (!_delay)
|
|
return -EINVAL;
|
|
|
|
delay = spi_delay_to_ns(_delay, xfer);
|
|
if (delay < 0)
|
|
return delay;
|
|
|
|
_spi_transfer_delay_ns(delay);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_delay_exec);
|
|
|
|
static void _spi_transfer_cs_change_delay(struct spi_message *msg,
|
|
struct spi_transfer *xfer)
|
|
{
|
|
u32 delay = xfer->cs_change_delay.value;
|
|
u32 unit = xfer->cs_change_delay.unit;
|
|
int ret;
|
|
|
|
/* return early on "fast" mode - for everything but USECS */
|
|
if (!delay) {
|
|
if (unit == SPI_DELAY_UNIT_USECS)
|
|
_spi_transfer_delay_ns(10000);
|
|
return;
|
|
}
|
|
|
|
ret = spi_delay_exec(&xfer->cs_change_delay, xfer);
|
|
if (ret) {
|
|
dev_err_once(&msg->spi->dev,
|
|
"Use of unsupported delay unit %i, using default of 10us\n",
|
|
unit);
|
|
_spi_transfer_delay_ns(10000);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* spi_transfer_one_message - Default implementation of transfer_one_message()
|
|
*
|
|
* This is a standard implementation of transfer_one_message() for
|
|
* drivers which implement a transfer_one() operation. It provides
|
|
* standard handling of delays and chip select management.
|
|
*/
|
|
static int spi_transfer_one_message(struct spi_controller *ctlr,
|
|
struct spi_message *msg)
|
|
{
|
|
struct spi_transfer *xfer;
|
|
bool keep_cs = false;
|
|
int ret = 0;
|
|
struct spi_statistics *statm = &ctlr->statistics;
|
|
struct spi_statistics *stats = &msg->spi->statistics;
|
|
|
|
spi_set_cs(msg->spi, true);
|
|
|
|
SPI_STATISTICS_INCREMENT_FIELD(statm, messages);
|
|
SPI_STATISTICS_INCREMENT_FIELD(stats, messages);
|
|
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
|
|
trace_spi_transfer_start(msg, xfer);
|
|
|
|
spi_statistics_add_transfer_stats(statm, xfer, ctlr);
|
|
spi_statistics_add_transfer_stats(stats, xfer, ctlr);
|
|
|
|
if (!ctlr->ptp_sts_supported) {
|
|
xfer->ptp_sts_word_pre = 0;
|
|
ptp_read_system_prets(xfer->ptp_sts);
|
|
}
|
|
|
|
if (xfer->tx_buf || xfer->rx_buf) {
|
|
reinit_completion(&ctlr->xfer_completion);
|
|
|
|
ret = ctlr->transfer_one(ctlr, msg->spi, xfer);
|
|
if (ret < 0) {
|
|
SPI_STATISTICS_INCREMENT_FIELD(statm,
|
|
errors);
|
|
SPI_STATISTICS_INCREMENT_FIELD(stats,
|
|
errors);
|
|
dev_err(&msg->spi->dev,
|
|
"SPI transfer failed: %d\n", ret);
|
|
goto out;
|
|
}
|
|
|
|
if (ret > 0) {
|
|
ret = spi_transfer_wait(ctlr, msg, xfer);
|
|
if (ret < 0)
|
|
msg->status = ret;
|
|
}
|
|
} else {
|
|
if (xfer->len)
|
|
dev_err(&msg->spi->dev,
|
|
"Bufferless transfer has length %u\n",
|
|
xfer->len);
|
|
}
|
|
|
|
if (!ctlr->ptp_sts_supported) {
|
|
ptp_read_system_postts(xfer->ptp_sts);
|
|
xfer->ptp_sts_word_post = xfer->len;
|
|
}
|
|
|
|
trace_spi_transfer_stop(msg, xfer);
|
|
|
|
if (msg->status != -EINPROGRESS)
|
|
goto out;
|
|
|
|
spi_transfer_delay_exec(xfer);
|
|
|
|
if (xfer->cs_change) {
|
|
if (list_is_last(&xfer->transfer_list,
|
|
&msg->transfers)) {
|
|
keep_cs = true;
|
|
} else {
|
|
spi_set_cs(msg->spi, false);
|
|
_spi_transfer_cs_change_delay(msg, xfer);
|
|
spi_set_cs(msg->spi, true);
|
|
}
|
|
}
|
|
|
|
msg->actual_length += xfer->len;
|
|
}
|
|
|
|
out:
|
|
if (ret != 0 || !keep_cs)
|
|
spi_set_cs(msg->spi, false);
|
|
|
|
if (msg->status == -EINPROGRESS)
|
|
msg->status = ret;
|
|
|
|
if (msg->status && ctlr->handle_err)
|
|
ctlr->handle_err(ctlr, msg);
|
|
|
|
spi_res_release(ctlr, msg);
|
|
|
|
spi_finalize_current_message(ctlr);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* spi_finalize_current_transfer - report completion of a transfer
|
|
* @ctlr: the controller reporting completion
|
|
*
|
|
* Called by SPI drivers using the core transfer_one_message()
|
|
* implementation to notify it that the current interrupt driven
|
|
* transfer has finished and the next one may be scheduled.
|
|
*/
|
|
void spi_finalize_current_transfer(struct spi_controller *ctlr)
|
|
{
|
|
complete(&ctlr->xfer_completion);
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_finalize_current_transfer);
|
|
|
|
/**
|
|
* __spi_pump_messages - function which processes spi message queue
|
|
* @ctlr: controller to process queue for
|
|
* @in_kthread: true if we are in the context of the message pump thread
|
|
*
|
|
* This function checks if there is any spi message in the queue that
|
|
* needs processing and if so call out to the driver to initialize hardware
|
|
* and transfer each message.
|
|
*
|
|
* Note that it is called both from the kthread itself and also from
|
|
* inside spi_sync(); the queue extraction handling at the top of the
|
|
* function should deal with this safely.
|
|
*/
|
|
static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
|
|
{
|
|
struct spi_transfer *xfer;
|
|
struct spi_message *msg;
|
|
bool was_busy = false;
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
/* Lock queue */
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags);
|
|
|
|
/* Make sure we are not already running a message */
|
|
if (ctlr->cur_msg) {
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
return;
|
|
}
|
|
|
|
/* If another context is idling the device then defer */
|
|
if (ctlr->idling) {
|
|
kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
return;
|
|
}
|
|
|
|
/* Check if the queue is idle */
|
|
if (list_empty(&ctlr->queue) || !ctlr->running) {
|
|
if (!ctlr->busy) {
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
return;
|
|
}
|
|
|
|
/* Only do teardown in the thread */
|
|
if (!in_kthread) {
|
|
kthread_queue_work(&ctlr->kworker,
|
|
&ctlr->pump_messages);
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
return;
|
|
}
|
|
|
|
ctlr->busy = false;
|
|
ctlr->idling = true;
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
|
|
kfree(ctlr->dummy_rx);
|
|
ctlr->dummy_rx = NULL;
|
|
kfree(ctlr->dummy_tx);
|
|
ctlr->dummy_tx = NULL;
|
|
if (ctlr->unprepare_transfer_hardware &&
|
|
ctlr->unprepare_transfer_hardware(ctlr))
|
|
dev_err(&ctlr->dev,
|
|
"failed to unprepare transfer hardware\n");
|
|
if (ctlr->auto_runtime_pm) {
|
|
pm_runtime_mark_last_busy(ctlr->dev.parent);
|
|
pm_runtime_put_autosuspend(ctlr->dev.parent);
|
|
}
|
|
trace_spi_controller_idle(ctlr);
|
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags);
|
|
ctlr->idling = false;
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
return;
|
|
}
|
|
|
|
/* Extract head of queue */
|
|
msg = list_first_entry(&ctlr->queue, struct spi_message, queue);
|
|
ctlr->cur_msg = msg;
|
|
|
|
list_del_init(&msg->queue);
|
|
if (ctlr->busy)
|
|
was_busy = true;
|
|
else
|
|
ctlr->busy = true;
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
|
|
mutex_lock(&ctlr->io_mutex);
|
|
|
|
if (!was_busy && ctlr->auto_runtime_pm) {
|
|
ret = pm_runtime_get_sync(ctlr->dev.parent);
|
|
if (ret < 0) {
|
|
pm_runtime_put_noidle(ctlr->dev.parent);
|
|
dev_err(&ctlr->dev, "Failed to power device: %d\n",
|
|
ret);
|
|
mutex_unlock(&ctlr->io_mutex);
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (!was_busy)
|
|
trace_spi_controller_busy(ctlr);
|
|
|
|
if (!was_busy && ctlr->prepare_transfer_hardware) {
|
|
ret = ctlr->prepare_transfer_hardware(ctlr);
|
|
if (ret) {
|
|
dev_err(&ctlr->dev,
|
|
"failed to prepare transfer hardware: %d\n",
|
|
ret);
|
|
|
|
if (ctlr->auto_runtime_pm)
|
|
pm_runtime_put(ctlr->dev.parent);
|
|
|
|
msg->status = ret;
|
|
spi_finalize_current_message(ctlr);
|
|
|
|
mutex_unlock(&ctlr->io_mutex);
|
|
return;
|
|
}
|
|
}
|
|
|
|
trace_spi_message_start(msg);
|
|
|
|
if (ctlr->prepare_message) {
|
|
ret = ctlr->prepare_message(ctlr, msg);
|
|
if (ret) {
|
|
dev_err(&ctlr->dev, "failed to prepare message: %d\n",
|
|
ret);
|
|
msg->status = ret;
|
|
spi_finalize_current_message(ctlr);
|
|
goto out;
|
|
}
|
|
ctlr->cur_msg_prepared = true;
|
|
}
|
|
|
|
ret = spi_map_msg(ctlr, msg);
|
|
if (ret) {
|
|
msg->status = ret;
|
|
spi_finalize_current_message(ctlr);
|
|
goto out;
|
|
}
|
|
|
|
if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
|
|
xfer->ptp_sts_word_pre = 0;
|
|
ptp_read_system_prets(xfer->ptp_sts);
|
|
}
|
|
}
|
|
|
|
ret = ctlr->transfer_one_message(ctlr, msg);
|
|
if (ret) {
|
|
dev_err(&ctlr->dev,
|
|
"failed to transfer one message from queue\n");
|
|
goto out;
|
|
}
|
|
|
|
out:
|
|
mutex_unlock(&ctlr->io_mutex);
|
|
|
|
/* Prod the scheduler in case transfer_one() was busy waiting */
|
|
if (!ret)
|
|
cond_resched();
|
|
}
|
|
|
|
/**
|
|
* spi_pump_messages - kthread work function which processes spi message queue
|
|
* @work: pointer to kthread work struct contained in the controller struct
|
|
*/
|
|
static void spi_pump_messages(struct kthread_work *work)
|
|
{
|
|
struct spi_controller *ctlr =
|
|
container_of(work, struct spi_controller, pump_messages);
|
|
|
|
__spi_pump_messages(ctlr, true);
|
|
}
|
|
|
|
/**
|
|
* spi_take_timestamp_pre - helper for drivers to collect the beginning of the
|
|
* TX timestamp for the requested byte from the SPI
|
|
* transfer. The frequency with which this function
|
|
* must be called (once per word, once for the whole
|
|
* transfer, once per batch of words etc) is arbitrary
|
|
* as long as the @tx buffer offset is greater than or
|
|
* equal to the requested byte at the time of the
|
|
* call. The timestamp is only taken once, at the
|
|
* first such call. It is assumed that the driver
|
|
* advances its @tx buffer pointer monotonically.
|
|
* @ctlr: Pointer to the spi_controller structure of the driver
|
|
* @xfer: Pointer to the transfer being timestamped
|
|
* @tx: Pointer to the current word within the xfer->tx_buf that the driver is
|
|
* preparing to transmit right now.
|
|
* @irqs_off: If true, will disable IRQs and preemption for the duration of the
|
|
* transfer, for less jitter in time measurement. Only compatible
|
|
* with PIO drivers. If true, must follow up with
|
|
* spi_take_timestamp_post or otherwise system will crash.
|
|
* WARNING: for fully predictable results, the CPU frequency must
|
|
* also be under control (governor).
|
|
*/
|
|
void spi_take_timestamp_pre(struct spi_controller *ctlr,
|
|
struct spi_transfer *xfer,
|
|
const void *tx, bool irqs_off)
|
|
{
|
|
u8 bytes_per_word = DIV_ROUND_UP(xfer->bits_per_word, 8);
|
|
|
|
if (!xfer->ptp_sts)
|
|
return;
|
|
|
|
if (xfer->timestamped_pre)
|
|
return;
|
|
|
|
if (tx < (xfer->tx_buf + xfer->ptp_sts_word_pre * bytes_per_word))
|
|
return;
|
|
|
|
/* Capture the resolution of the timestamp */
|
|
xfer->ptp_sts_word_pre = (tx - xfer->tx_buf) / bytes_per_word;
|
|
|
|
xfer->timestamped_pre = true;
|
|
|
|
if (irqs_off) {
|
|
local_irq_save(ctlr->irq_flags);
|
|
preempt_disable();
|
|
}
|
|
|
|
ptp_read_system_prets(xfer->ptp_sts);
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_take_timestamp_pre);
|
|
|
|
/**
|
|
* spi_take_timestamp_post - helper for drivers to collect the end of the
|
|
* TX timestamp for the requested byte from the SPI
|
|
* transfer. Can be called with an arbitrary
|
|
* frequency: only the first call where @tx exceeds
|
|
* or is equal to the requested word will be
|
|
* timestamped.
|
|
* @ctlr: Pointer to the spi_controller structure of the driver
|
|
* @xfer: Pointer to the transfer being timestamped
|
|
* @tx: Pointer to the current word within the xfer->tx_buf that the driver has
|
|
* just transmitted.
|
|
* @irqs_off: If true, will re-enable IRQs and preemption for the local CPU.
|
|
*/
|
|
void spi_take_timestamp_post(struct spi_controller *ctlr,
|
|
struct spi_transfer *xfer,
|
|
const void *tx, bool irqs_off)
|
|
{
|
|
u8 bytes_per_word = DIV_ROUND_UP(xfer->bits_per_word, 8);
|
|
|
|
if (!xfer->ptp_sts)
|
|
return;
|
|
|
|
if (xfer->timestamped_post)
|
|
return;
|
|
|
|
if (tx < (xfer->tx_buf + xfer->ptp_sts_word_post * bytes_per_word))
|
|
return;
|
|
|
|
ptp_read_system_postts(xfer->ptp_sts);
|
|
|
|
if (irqs_off) {
|
|
local_irq_restore(ctlr->irq_flags);
|
|
preempt_enable();
|
|
}
|
|
|
|
/* Capture the resolution of the timestamp */
|
|
xfer->ptp_sts_word_post = (tx - xfer->tx_buf) / bytes_per_word;
|
|
|
|
xfer->timestamped_post = true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_take_timestamp_post);
|
|
|
|
/**
|
|
* spi_set_thread_rt - set the controller to pump at realtime priority
|
|
* @ctlr: controller to boost priority of
|
|
*
|
|
* This can be called because the controller requested realtime priority
|
|
* (by setting the ->rt value before calling spi_register_controller()) or
|
|
* because a device on the bus said that its transfers needed realtime
|
|
* priority.
|
|
*
|
|
* NOTE: at the moment if any device on a bus says it needs realtime then
|
|
* the thread will be at realtime priority for all transfers on that
|
|
* controller. If this eventually becomes a problem we may see if we can
|
|
* find a way to boost the priority only temporarily during relevant
|
|
* transfers.
|
|
*/
|
|
static void spi_set_thread_rt(struct spi_controller *ctlr)
|
|
{
|
|
struct sched_param param = { .sched_priority = MAX_RT_PRIO / 2 };
|
|
|
|
dev_info(&ctlr->dev,
|
|
"will run message pump with realtime priority\n");
|
|
sched_setscheduler(ctlr->kworker_task, SCHED_FIFO, ¶m);
|
|
}
|
|
|
|
static int spi_init_queue(struct spi_controller *ctlr)
|
|
{
|
|
ctlr->running = false;
|
|
ctlr->busy = false;
|
|
|
|
kthread_init_worker(&ctlr->kworker);
|
|
ctlr->kworker_task = kthread_run(kthread_worker_fn, &ctlr->kworker,
|
|
"%s", dev_name(&ctlr->dev));
|
|
if (IS_ERR(ctlr->kworker_task)) {
|
|
dev_err(&ctlr->dev, "failed to create message pump task\n");
|
|
return PTR_ERR(ctlr->kworker_task);
|
|
}
|
|
kthread_init_work(&ctlr->pump_messages, spi_pump_messages);
|
|
|
|
/*
|
|
* Controller config will indicate if this controller should run the
|
|
* message pump with high (realtime) priority to reduce the transfer
|
|
* latency on the bus by minimising the delay between a transfer
|
|
* request and the scheduling of the message pump thread. Without this
|
|
* setting the message pump thread will remain at default priority.
|
|
*/
|
|
if (ctlr->rt)
|
|
spi_set_thread_rt(ctlr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* spi_get_next_queued_message() - called by driver to check for queued
|
|
* messages
|
|
* @ctlr: the controller to check for queued messages
|
|
*
|
|
* If there are more messages in the queue, the next message is returned from
|
|
* this call.
|
|
*
|
|
* Return: the next message in the queue, else NULL if the queue is empty.
|
|
*/
|
|
struct spi_message *spi_get_next_queued_message(struct spi_controller *ctlr)
|
|
{
|
|
struct spi_message *next;
|
|
unsigned long flags;
|
|
|
|
/* get a pointer to the next message, if any */
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags);
|
|
next = list_first_entry_or_null(&ctlr->queue, struct spi_message,
|
|
queue);
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
|
|
return next;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_get_next_queued_message);
|
|
|
|
/**
|
|
* spi_finalize_current_message() - the current message is complete
|
|
* @ctlr: the controller to return the message to
|
|
*
|
|
* Called by the driver to notify the core that the message in the front of the
|
|
* queue is complete and can be removed from the queue.
|
|
*/
|
|
void spi_finalize_current_message(struct spi_controller *ctlr)
|
|
{
|
|
struct spi_transfer *xfer;
|
|
struct spi_message *mesg;
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags);
|
|
mesg = ctlr->cur_msg;
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
|
|
if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) {
|
|
list_for_each_entry(xfer, &mesg->transfers, transfer_list) {
|
|
ptp_read_system_postts(xfer->ptp_sts);
|
|
xfer->ptp_sts_word_post = xfer->len;
|
|
}
|
|
}
|
|
|
|
spi_unmap_msg(ctlr, mesg);
|
|
|
|
if (ctlr->cur_msg_prepared && ctlr->unprepare_message) {
|
|
ret = ctlr->unprepare_message(ctlr, mesg);
|
|
if (ret) {
|
|
dev_err(&ctlr->dev, "failed to unprepare message: %d\n",
|
|
ret);
|
|
}
|
|
}
|
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags);
|
|
ctlr->cur_msg = NULL;
|
|
ctlr->cur_msg_prepared = false;
|
|
kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
|
|
trace_spi_message_done(mesg);
|
|
|
|
mesg->state = NULL;
|
|
if (mesg->complete)
|
|
mesg->complete(mesg->context);
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_finalize_current_message);
|
|
|
|
static int spi_start_queue(struct spi_controller *ctlr)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags);
|
|
|
|
if (ctlr->running || ctlr->busy) {
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
return -EBUSY;
|
|
}
|
|
|
|
ctlr->running = true;
|
|
ctlr->cur_msg = NULL;
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
|
|
kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int spi_stop_queue(struct spi_controller *ctlr)
|
|
{
|
|
unsigned long flags;
|
|
unsigned limit = 500;
|
|
int ret = 0;
|
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags);
|
|
|
|
/*
|
|
* This is a bit lame, but is optimized for the common execution path.
|
|
* A wait_queue on the ctlr->busy could be used, but then the common
|
|
* execution path (pump_messages) would be required to call wake_up or
|
|
* friends on every SPI message. Do this instead.
|
|
*/
|
|
while ((!list_empty(&ctlr->queue) || ctlr->busy) && limit--) {
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
usleep_range(10000, 11000);
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags);
|
|
}
|
|
|
|
if (!list_empty(&ctlr->queue) || ctlr->busy)
|
|
ret = -EBUSY;
|
|
else
|
|
ctlr->running = false;
|
|
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
|
|
if (ret) {
|
|
dev_warn(&ctlr->dev, "could not stop message queue\n");
|
|
return ret;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int spi_destroy_queue(struct spi_controller *ctlr)
|
|
{
|
|
int ret;
|
|
|
|
ret = spi_stop_queue(ctlr);
|
|
|
|
/*
|
|
* kthread_flush_worker will block until all work is done.
|
|
* If the reason that stop_queue timed out is that the work will never
|
|
* finish, then it does no good to call flush/stop thread, so
|
|
* return anyway.
|
|
*/
|
|
if (ret) {
|
|
dev_err(&ctlr->dev, "problem destroying queue\n");
|
|
return ret;
|
|
}
|
|
|
|
kthread_flush_worker(&ctlr->kworker);
|
|
kthread_stop(ctlr->kworker_task);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __spi_queued_transfer(struct spi_device *spi,
|
|
struct spi_message *msg,
|
|
bool need_pump)
|
|
{
|
|
struct spi_controller *ctlr = spi->controller;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&ctlr->queue_lock, flags);
|
|
|
|
if (!ctlr->running) {
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
return -ESHUTDOWN;
|
|
}
|
|
msg->actual_length = 0;
|
|
msg->status = -EINPROGRESS;
|
|
|
|
list_add_tail(&msg->queue, &ctlr->queue);
|
|
if (!ctlr->busy && need_pump)
|
|
kthread_queue_work(&ctlr->kworker, &ctlr->pump_messages);
|
|
|
|
spin_unlock_irqrestore(&ctlr->queue_lock, flags);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* spi_queued_transfer - transfer function for queued transfers
|
|
* @spi: spi device which is requesting transfer
|
|
* @msg: spi message which is to handled is queued to driver queue
|
|
*
|
|
* Return: zero on success, else a negative error code.
|
|
*/
|
|
static int spi_queued_transfer(struct spi_device *spi, struct spi_message *msg)
|
|
{
|
|
return __spi_queued_transfer(spi, msg, true);
|
|
}
|
|
|
|
static int spi_controller_initialize_queue(struct spi_controller *ctlr)
|
|
{
|
|
int ret;
|
|
|
|
ctlr->transfer = spi_queued_transfer;
|
|
if (!ctlr->transfer_one_message)
|
|
ctlr->transfer_one_message = spi_transfer_one_message;
|
|
|
|
/* Initialize and start queue */
|
|
ret = spi_init_queue(ctlr);
|
|
if (ret) {
|
|
dev_err(&ctlr->dev, "problem initializing queue\n");
|
|
goto err_init_queue;
|
|
}
|
|
ctlr->queued = true;
|
|
ret = spi_start_queue(ctlr);
|
|
if (ret) {
|
|
dev_err(&ctlr->dev, "problem starting queue\n");
|
|
goto err_start_queue;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_start_queue:
|
|
spi_destroy_queue(ctlr);
|
|
err_init_queue:
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* spi_flush_queue - Send all pending messages in the queue from the callers'
|
|
* context
|
|
* @ctlr: controller to process queue for
|
|
*
|
|
* This should be used when one wants to ensure all pending messages have been
|
|
* sent before doing something. Is used by the spi-mem code to make sure SPI
|
|
* memory operations do not preempt regular SPI transfers that have been queued
|
|
* before the spi-mem operation.
|
|
*/
|
|
void spi_flush_queue(struct spi_controller *ctlr)
|
|
{
|
|
if (ctlr->transfer == spi_queued_transfer)
|
|
__spi_pump_messages(ctlr, false);
|
|
}
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
#if defined(CONFIG_OF)
|
|
static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
|
|
struct device_node *nc)
|
|
{
|
|
u32 value;
|
|
int rc;
|
|
|
|
/* Mode (clock phase/polarity/etc.) */
|
|
if (of_property_read_bool(nc, "spi-cpha"))
|
|
spi->mode |= SPI_CPHA;
|
|
if (of_property_read_bool(nc, "spi-cpol"))
|
|
spi->mode |= SPI_CPOL;
|
|
if (of_property_read_bool(nc, "spi-3wire"))
|
|
spi->mode |= SPI_3WIRE;
|
|
if (of_property_read_bool(nc, "spi-lsb-first"))
|
|
spi->mode |= SPI_LSB_FIRST;
|
|
if (of_property_read_bool(nc, "spi-cs-high"))
|
|
spi->mode |= SPI_CS_HIGH;
|
|
|
|
/* Device DUAL/QUAD mode */
|
|
if (!of_property_read_u32(nc, "spi-tx-bus-width", &value)) {
|
|
switch (value) {
|
|
case 1:
|
|
break;
|
|
case 2:
|
|
spi->mode |= SPI_TX_DUAL;
|
|
break;
|
|
case 4:
|
|
spi->mode |= SPI_TX_QUAD;
|
|
break;
|
|
case 8:
|
|
spi->mode |= SPI_TX_OCTAL;
|
|
break;
|
|
default:
|
|
dev_warn(&ctlr->dev,
|
|
"spi-tx-bus-width %d not supported\n",
|
|
value);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!of_property_read_u32(nc, "spi-rx-bus-width", &value)) {
|
|
switch (value) {
|
|
case 1:
|
|
break;
|
|
case 2:
|
|
spi->mode |= SPI_RX_DUAL;
|
|
break;
|
|
case 4:
|
|
spi->mode |= SPI_RX_QUAD;
|
|
break;
|
|
case 8:
|
|
spi->mode |= SPI_RX_OCTAL;
|
|
break;
|
|
default:
|
|
dev_warn(&ctlr->dev,
|
|
"spi-rx-bus-width %d not supported\n",
|
|
value);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (spi_controller_is_slave(ctlr)) {
|
|
if (!of_node_name_eq(nc, "slave")) {
|
|
dev_err(&ctlr->dev, "%pOF is not called 'slave'\n",
|
|
nc);
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* Device address */
|
|
rc = of_property_read_u32(nc, "reg", &value);
|
|
if (rc) {
|
|
dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n",
|
|
nc, rc);
|
|
return rc;
|
|
}
|
|
spi->chip_select = value;
|
|
|
|
/*
|
|
* For descriptors associated with the device, polarity inversion is
|
|
* handled in the gpiolib, so all gpio chip selects are "active high"
|
|
* in the logical sense, the gpiolib will invert the line if need be.
|
|
*/
|
|
if ((ctlr->use_gpio_descriptors) && ctlr->cs_gpiods &&
|
|
ctlr->cs_gpiods[spi->chip_select])
|
|
spi->mode |= SPI_CS_HIGH;
|
|
|
|
/* Device speed */
|
|
rc = of_property_read_u32(nc, "spi-max-frequency", &value);
|
|
if (rc) {
|
|
dev_err(&ctlr->dev,
|
|
"%pOF has no valid 'spi-max-frequency' property (%d)\n", nc, rc);
|
|
return rc;
|
|
}
|
|
spi->max_speed_hz = value;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct spi_device *
|
|
of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc)
|
|
{
|
|
struct spi_device *spi;
|
|
int rc;
|
|
|
|
/* Alloc an spi_device */
|
|
spi = spi_alloc_device(ctlr);
|
|
if (!spi) {
|
|
dev_err(&ctlr->dev, "spi_device alloc error for %pOF\n", nc);
|
|
rc = -ENOMEM;
|
|
goto err_out;
|
|
}
|
|
|
|
/* Select device driver */
|
|
rc = of_modalias_node(nc, spi->modalias,
|
|
sizeof(spi->modalias));
|
|
if (rc < 0) {
|
|
dev_err(&ctlr->dev, "cannot find modalias for %pOF\n", nc);
|
|
goto err_out;
|
|
}
|
|
|
|
rc = of_spi_parse_dt(ctlr, spi, nc);
|
|
if (rc)
|
|
goto err_out;
|
|
|
|
/* Store a pointer to the node in the device structure */
|
|
of_node_get(nc);
|
|
spi->dev.of_node = nc;
|
|
|
|
/* Register the new device */
|
|
rc = spi_add_device(spi);
|
|
if (rc) {
|
|
dev_err(&ctlr->dev, "spi_device register error %pOF\n", nc);
|
|
goto err_of_node_put;
|
|
}
|
|
|
|
return spi;
|
|
|
|
err_of_node_put:
|
|
of_node_put(nc);
|
|
err_out:
|
|
spi_dev_put(spi);
|
|
return ERR_PTR(rc);
|
|
}
|
|
|
|
/**
|
|
* of_register_spi_devices() - Register child devices onto the SPI bus
|
|
* @ctlr: Pointer to spi_controller device
|
|
*
|
|
* Registers an spi_device for each child node of controller node which
|
|
* represents a valid SPI slave.
|
|
*/
|
|
static void of_register_spi_devices(struct spi_controller *ctlr)
|
|
{
|
|
struct spi_device *spi;
|
|
struct device_node *nc;
|
|
|
|
if (!ctlr->dev.of_node)
|
|
return;
|
|
|
|
for_each_available_child_of_node(ctlr->dev.of_node, nc) {
|
|
if (of_node_test_and_set_flag(nc, OF_POPULATED))
|
|
continue;
|
|
spi = of_register_spi_device(ctlr, nc);
|
|
if (IS_ERR(spi)) {
|
|
dev_warn(&ctlr->dev,
|
|
"Failed to create SPI device for %pOF\n", nc);
|
|
of_node_clear_flag(nc, OF_POPULATED);
|
|
}
|
|
}
|
|
}
|
|
#else
|
|
static void of_register_spi_devices(struct spi_controller *ctlr) { }
|
|
#endif
|
|
|
|
#ifdef CONFIG_ACPI
|
|
struct acpi_spi_lookup {
|
|
struct spi_controller *ctlr;
|
|
u32 max_speed_hz;
|
|
u32 mode;
|
|
int irq;
|
|
u8 bits_per_word;
|
|
u8 chip_select;
|
|
};
|
|
|
|
static void acpi_spi_parse_apple_properties(struct acpi_device *dev,
|
|
struct acpi_spi_lookup *lookup)
|
|
{
|
|
const union acpi_object *obj;
|
|
|
|
if (!x86_apple_machine)
|
|
return;
|
|
|
|
if (!acpi_dev_get_property(dev, "spiSclkPeriod", ACPI_TYPE_BUFFER, &obj)
|
|
&& obj->buffer.length >= 4)
|
|
lookup->max_speed_hz = NSEC_PER_SEC / *(u32 *)obj->buffer.pointer;
|
|
|
|
if (!acpi_dev_get_property(dev, "spiWordSize", ACPI_TYPE_BUFFER, &obj)
|
|
&& obj->buffer.length == 8)
|
|
lookup->bits_per_word = *(u64 *)obj->buffer.pointer;
|
|
|
|
if (!acpi_dev_get_property(dev, "spiBitOrder", ACPI_TYPE_BUFFER, &obj)
|
|
&& obj->buffer.length == 8 && !*(u64 *)obj->buffer.pointer)
|
|
lookup->mode |= SPI_LSB_FIRST;
|
|
|
|
if (!acpi_dev_get_property(dev, "spiSPO", ACPI_TYPE_BUFFER, &obj)
|
|
&& obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
|
|
lookup->mode |= SPI_CPOL;
|
|
|
|
if (!acpi_dev_get_property(dev, "spiSPH", ACPI_TYPE_BUFFER, &obj)
|
|
&& obj->buffer.length == 8 && *(u64 *)obj->buffer.pointer)
|
|
lookup->mode |= SPI_CPHA;
|
|
}
|
|
|
|
static int acpi_spi_add_resource(struct acpi_resource *ares, void *data)
|
|
{
|
|
struct acpi_spi_lookup *lookup = data;
|
|
struct spi_controller *ctlr = lookup->ctlr;
|
|
|
|
if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) {
|
|
struct acpi_resource_spi_serialbus *sb;
|
|
acpi_handle parent_handle;
|
|
acpi_status status;
|
|
|
|
sb = &ares->data.spi_serial_bus;
|
|
if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) {
|
|
|
|
status = acpi_get_handle(NULL,
|
|
sb->resource_source.string_ptr,
|
|
&parent_handle);
|
|
|
|
if (ACPI_FAILURE(status) ||
|
|
ACPI_HANDLE(ctlr->dev.parent) != parent_handle)
|
|
return -ENODEV;
|
|
|
|
/*
|
|
* ACPI DeviceSelection numbering is handled by the
|
|
* host controller driver in Windows and can vary
|
|
* from driver to driver. In Linux we always expect
|
|
* 0 .. max - 1 so we need to ask the driver to
|
|
* translate between the two schemes.
|
|
*/
|
|
if (ctlr->fw_translate_cs) {
|
|
int cs = ctlr->fw_translate_cs(ctlr,
|
|
sb->device_selection);
|
|
if (cs < 0)
|
|
return cs;
|
|
lookup->chip_select = cs;
|
|
} else {
|
|
lookup->chip_select = sb->device_selection;
|
|
}
|
|
|
|
lookup->max_speed_hz = sb->connection_speed;
|
|
|
|
if (sb->clock_phase == ACPI_SPI_SECOND_PHASE)
|
|
lookup->mode |= SPI_CPHA;
|
|
if (sb->clock_polarity == ACPI_SPI_START_HIGH)
|
|
lookup->mode |= SPI_CPOL;
|
|
if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH)
|
|
lookup->mode |= SPI_CS_HIGH;
|
|
}
|
|
} else if (lookup->irq < 0) {
|
|
struct resource r;
|
|
|
|
if (acpi_dev_resource_interrupt(ares, 0, &r))
|
|
lookup->irq = r.start;
|
|
}
|
|
|
|
/* Always tell the ACPI core to skip this resource */
|
|
return 1;
|
|
}
|
|
|
|
static acpi_status acpi_register_spi_device(struct spi_controller *ctlr,
|
|
struct acpi_device *adev)
|
|
{
|
|
acpi_handle parent_handle = NULL;
|
|
struct list_head resource_list;
|
|
struct acpi_spi_lookup lookup = {};
|
|
struct spi_device *spi;
|
|
int ret;
|
|
|
|
if (acpi_bus_get_status(adev) || !adev->status.present ||
|
|
acpi_device_enumerated(adev))
|
|
return AE_OK;
|
|
|
|
lookup.ctlr = ctlr;
|
|
lookup.irq = -1;
|
|
|
|
INIT_LIST_HEAD(&resource_list);
|
|
ret = acpi_dev_get_resources(adev, &resource_list,
|
|
acpi_spi_add_resource, &lookup);
|
|
acpi_dev_free_resource_list(&resource_list);
|
|
|
|
if (ret < 0)
|
|
/* found SPI in _CRS but it points to another controller */
|
|
return AE_OK;
|
|
|
|
if (!lookup.max_speed_hz &&
|
|
!ACPI_FAILURE(acpi_get_parent(adev->handle, &parent_handle)) &&
|
|
ACPI_HANDLE(ctlr->dev.parent) == parent_handle) {
|
|
/* Apple does not use _CRS but nested devices for SPI slaves */
|
|
acpi_spi_parse_apple_properties(adev, &lookup);
|
|
}
|
|
|
|
if (!lookup.max_speed_hz)
|
|
return AE_OK;
|
|
|
|
spi = spi_alloc_device(ctlr);
|
|
if (!spi) {
|
|
dev_err(&ctlr->dev, "failed to allocate SPI device for %s\n",
|
|
dev_name(&adev->dev));
|
|
return AE_NO_MEMORY;
|
|
}
|
|
|
|
ACPI_COMPANION_SET(&spi->dev, adev);
|
|
spi->max_speed_hz = lookup.max_speed_hz;
|
|
spi->mode = lookup.mode;
|
|
spi->irq = lookup.irq;
|
|
spi->bits_per_word = lookup.bits_per_word;
|
|
spi->chip_select = lookup.chip_select;
|
|
|
|
acpi_set_modalias(adev, acpi_device_hid(adev), spi->modalias,
|
|
sizeof(spi->modalias));
|
|
|
|
if (spi->irq < 0)
|
|
spi->irq = acpi_dev_gpio_irq_get(adev, 0);
|
|
|
|
acpi_device_set_enumerated(adev);
|
|
|
|
adev->power.flags.ignore_parent = true;
|
|
if (spi_add_device(spi)) {
|
|
adev->power.flags.ignore_parent = false;
|
|
dev_err(&ctlr->dev, "failed to add SPI device %s from ACPI\n",
|
|
dev_name(&adev->dev));
|
|
spi_dev_put(spi);
|
|
}
|
|
|
|
return AE_OK;
|
|
}
|
|
|
|
static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level,
|
|
void *data, void **return_value)
|
|
{
|
|
struct spi_controller *ctlr = data;
|
|
struct acpi_device *adev;
|
|
|
|
if (acpi_bus_get_device(handle, &adev))
|
|
return AE_OK;
|
|
|
|
return acpi_register_spi_device(ctlr, adev);
|
|
}
|
|
|
|
#define SPI_ACPI_ENUMERATE_MAX_DEPTH 32
|
|
|
|
static void acpi_register_spi_devices(struct spi_controller *ctlr)
|
|
{
|
|
acpi_status status;
|
|
acpi_handle handle;
|
|
|
|
handle = ACPI_HANDLE(ctlr->dev.parent);
|
|
if (!handle)
|
|
return;
|
|
|
|
status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
|
|
SPI_ACPI_ENUMERATE_MAX_DEPTH,
|
|
acpi_spi_add_device, NULL, ctlr, NULL);
|
|
if (ACPI_FAILURE(status))
|
|
dev_warn(&ctlr->dev, "failed to enumerate SPI slaves\n");
|
|
}
|
|
#else
|
|
static inline void acpi_register_spi_devices(struct spi_controller *ctlr) {}
|
|
#endif /* CONFIG_ACPI */
|
|
|
|
static void spi_controller_release(struct device *dev)
|
|
{
|
|
struct spi_controller *ctlr;
|
|
|
|
ctlr = container_of(dev, struct spi_controller, dev);
|
|
kfree(ctlr);
|
|
}
|
|
|
|
static struct class spi_master_class = {
|
|
.name = "spi_master",
|
|
.owner = THIS_MODULE,
|
|
.dev_release = spi_controller_release,
|
|
.dev_groups = spi_master_groups,
|
|
};
|
|
|
|
#ifdef CONFIG_SPI_SLAVE
|
|
/**
|
|
* spi_slave_abort - abort the ongoing transfer request on an SPI slave
|
|
* controller
|
|
* @spi: device used for the current transfer
|
|
*/
|
|
int spi_slave_abort(struct spi_device *spi)
|
|
{
|
|
struct spi_controller *ctlr = spi->controller;
|
|
|
|
if (spi_controller_is_slave(ctlr) && ctlr->slave_abort)
|
|
return ctlr->slave_abort(ctlr);
|
|
|
|
return -ENOTSUPP;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_slave_abort);
|
|
|
|
static int match_true(struct device *dev, void *data)
|
|
{
|
|
return 1;
|
|
}
|
|
|
|
static ssize_t slave_show(struct device *dev, struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct spi_controller *ctlr = container_of(dev, struct spi_controller,
|
|
dev);
|
|
struct device *child;
|
|
|
|
child = device_find_child(&ctlr->dev, NULL, match_true);
|
|
return sprintf(buf, "%s\n",
|
|
child ? to_spi_device(child)->modalias : NULL);
|
|
}
|
|
|
|
static ssize_t slave_store(struct device *dev, struct device_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct spi_controller *ctlr = container_of(dev, struct spi_controller,
|
|
dev);
|
|
struct spi_device *spi;
|
|
struct device *child;
|
|
char name[32];
|
|
int rc;
|
|
|
|
rc = sscanf(buf, "%31s", name);
|
|
if (rc != 1 || !name[0])
|
|
return -EINVAL;
|
|
|
|
child = device_find_child(&ctlr->dev, NULL, match_true);
|
|
if (child) {
|
|
/* Remove registered slave */
|
|
device_unregister(child);
|
|
put_device(child);
|
|
}
|
|
|
|
if (strcmp(name, "(null)")) {
|
|
/* Register new slave */
|
|
spi = spi_alloc_device(ctlr);
|
|
if (!spi)
|
|
return -ENOMEM;
|
|
|
|
strlcpy(spi->modalias, name, sizeof(spi->modalias));
|
|
|
|
rc = spi_add_device(spi);
|
|
if (rc) {
|
|
spi_dev_put(spi);
|
|
return rc;
|
|
}
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
static DEVICE_ATTR_RW(slave);
|
|
|
|
static struct attribute *spi_slave_attrs[] = {
|
|
&dev_attr_slave.attr,
|
|
NULL,
|
|
};
|
|
|
|
static const struct attribute_group spi_slave_group = {
|
|
.attrs = spi_slave_attrs,
|
|
};
|
|
|
|
static const struct attribute_group *spi_slave_groups[] = {
|
|
&spi_controller_statistics_group,
|
|
&spi_slave_group,
|
|
NULL,
|
|
};
|
|
|
|
static struct class spi_slave_class = {
|
|
.name = "spi_slave",
|
|
.owner = THIS_MODULE,
|
|
.dev_release = spi_controller_release,
|
|
.dev_groups = spi_slave_groups,
|
|
};
|
|
#else
|
|
extern struct class spi_slave_class; /* dummy */
|
|
#endif
|
|
|
|
/**
|
|
* __spi_alloc_controller - allocate an SPI master or slave controller
|
|
* @dev: the controller, possibly using the platform_bus
|
|
* @size: how much zeroed driver-private data to allocate; the pointer to this
|
|
* memory is in the driver_data field of the returned device, accessible
|
|
* with spi_controller_get_devdata(); the memory is cacheline aligned;
|
|
* drivers granting DMA access to portions of their private data need to
|
|
* round up @size using ALIGN(size, dma_get_cache_alignment()).
|
|
* @slave: flag indicating whether to allocate an SPI master (false) or SPI
|
|
* slave (true) controller
|
|
* Context: can sleep
|
|
*
|
|
* This call is used only by SPI controller drivers, which are the
|
|
* only ones directly touching chip registers. It's how they allocate
|
|
* an spi_controller structure, prior to calling spi_register_controller().
|
|
*
|
|
* This must be called from context that can sleep.
|
|
*
|
|
* The caller is responsible for assigning the bus number and initializing the
|
|
* controller's methods before calling spi_register_controller(); and (after
|
|
* errors adding the device) calling spi_controller_put() to prevent a memory
|
|
* leak.
|
|
*
|
|
* Return: the SPI controller structure on success, else NULL.
|
|
*/
|
|
struct spi_controller *__spi_alloc_controller(struct device *dev,
|
|
unsigned int size, bool slave)
|
|
{
|
|
struct spi_controller *ctlr;
|
|
size_t ctlr_size = ALIGN(sizeof(*ctlr), dma_get_cache_alignment());
|
|
|
|
if (!dev)
|
|
return NULL;
|
|
|
|
ctlr = kzalloc(size + ctlr_size, GFP_KERNEL);
|
|
if (!ctlr)
|
|
return NULL;
|
|
|
|
device_initialize(&ctlr->dev);
|
|
ctlr->bus_num = -1;
|
|
ctlr->num_chipselect = 1;
|
|
ctlr->slave = slave;
|
|
if (IS_ENABLED(CONFIG_SPI_SLAVE) && slave)
|
|
ctlr->dev.class = &spi_slave_class;
|
|
else
|
|
ctlr->dev.class = &spi_master_class;
|
|
ctlr->dev.parent = dev;
|
|
pm_suspend_ignore_children(&ctlr->dev, true);
|
|
spi_controller_set_devdata(ctlr, (void *)ctlr + ctlr_size);
|
|
|
|
return ctlr;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__spi_alloc_controller);
|
|
|
|
#ifdef CONFIG_OF
|
|
static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
|
|
{
|
|
int nb, i, *cs;
|
|
struct device_node *np = ctlr->dev.of_node;
|
|
|
|
if (!np)
|
|
return 0;
|
|
|
|
nb = of_gpio_named_count(np, "cs-gpios");
|
|
ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
|
|
|
|
/* Return error only for an incorrectly formed cs-gpios property */
|
|
if (nb == 0 || nb == -ENOENT)
|
|
return 0;
|
|
else if (nb < 0)
|
|
return nb;
|
|
|
|
cs = devm_kcalloc(&ctlr->dev, ctlr->num_chipselect, sizeof(int),
|
|
GFP_KERNEL);
|
|
ctlr->cs_gpios = cs;
|
|
|
|
if (!ctlr->cs_gpios)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; i < ctlr->num_chipselect; i++)
|
|
cs[i] = -ENOENT;
|
|
|
|
for (i = 0; i < nb; i++)
|
|
cs[i] = of_get_named_gpio(np, "cs-gpios", i);
|
|
|
|
return 0;
|
|
}
|
|
#else
|
|
static int of_spi_get_gpio_numbers(struct spi_controller *ctlr)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* spi_get_gpio_descs() - grab chip select GPIOs for the master
|
|
* @ctlr: The SPI master to grab GPIO descriptors for
|
|
*/
|
|
static int spi_get_gpio_descs(struct spi_controller *ctlr)
|
|
{
|
|
int nb, i;
|
|
struct gpio_desc **cs;
|
|
struct device *dev = &ctlr->dev;
|
|
|
|
nb = gpiod_count(dev, "cs");
|
|
ctlr->num_chipselect = max_t(int, nb, ctlr->num_chipselect);
|
|
|
|
/* No GPIOs at all is fine, else return the error */
|
|
if (nb == 0 || nb == -ENOENT)
|
|
return 0;
|
|
else if (nb < 0)
|
|
return nb;
|
|
|
|
cs = devm_kcalloc(dev, ctlr->num_chipselect, sizeof(*cs),
|
|
GFP_KERNEL);
|
|
if (!cs)
|
|
return -ENOMEM;
|
|
ctlr->cs_gpiods = cs;
|
|
|
|
for (i = 0; i < nb; i++) {
|
|
/*
|
|
* Most chipselects are active low, the inverted
|
|
* semantics are handled by special quirks in gpiolib,
|
|
* so initializing them GPIOD_OUT_LOW here means
|
|
* "unasserted", in most cases this will drive the physical
|
|
* line high.
|
|
*/
|
|
cs[i] = devm_gpiod_get_index_optional(dev, "cs", i,
|
|
GPIOD_OUT_LOW);
|
|
if (IS_ERR(cs[i]))
|
|
return PTR_ERR(cs[i]);
|
|
|
|
if (cs[i]) {
|
|
/*
|
|
* If we find a CS GPIO, name it after the device and
|
|
* chip select line.
|
|
*/
|
|
char *gpioname;
|
|
|
|
gpioname = devm_kasprintf(dev, GFP_KERNEL, "%s CS%d",
|
|
dev_name(dev), i);
|
|
if (!gpioname)
|
|
return -ENOMEM;
|
|
gpiod_set_consumer_name(cs[i], gpioname);
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int spi_controller_check_ops(struct spi_controller *ctlr)
|
|
{
|
|
/*
|
|
* The controller may implement only the high-level SPI-memory like
|
|
* operations if it does not support regular SPI transfers, and this is
|
|
* valid use case.
|
|
* If ->mem_ops is NULL, we request that at least one of the
|
|
* ->transfer_xxx() method be implemented.
|
|
*/
|
|
if (ctlr->mem_ops) {
|
|
if (!ctlr->mem_ops->exec_op)
|
|
return -EINVAL;
|
|
} else if (!ctlr->transfer && !ctlr->transfer_one &&
|
|
!ctlr->transfer_one_message) {
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* spi_register_controller - register SPI master or slave controller
|
|
* @ctlr: initialized master, originally from spi_alloc_master() or
|
|
* spi_alloc_slave()
|
|
* Context: can sleep
|
|
*
|
|
* SPI controllers connect to their drivers using some non-SPI bus,
|
|
* such as the platform bus. The final stage of probe() in that code
|
|
* includes calling spi_register_controller() to hook up to this SPI bus glue.
|
|
*
|
|
* SPI controllers use board specific (often SOC specific) bus numbers,
|
|
* and board-specific addressing for SPI devices combines those numbers
|
|
* with chip select numbers. Since SPI does not directly support dynamic
|
|
* device identification, boards need configuration tables telling which
|
|
* chip is at which address.
|
|
*
|
|
* This must be called from context that can sleep. It returns zero on
|
|
* success, else a negative error code (dropping the controller's refcount).
|
|
* After a successful return, the caller is responsible for calling
|
|
* spi_unregister_controller().
|
|
*
|
|
* Return: zero on success, else a negative error code.
|
|
*/
|
|
int spi_register_controller(struct spi_controller *ctlr)
|
|
{
|
|
struct device *dev = ctlr->dev.parent;
|
|
struct boardinfo *bi;
|
|
int status;
|
|
int id, first_dynamic;
|
|
|
|
if (!dev)
|
|
return -ENODEV;
|
|
|
|
/*
|
|
* Make sure all necessary hooks are implemented before registering
|
|
* the SPI controller.
|
|
*/
|
|
status = spi_controller_check_ops(ctlr);
|
|
if (status)
|
|
return status;
|
|
|
|
if (ctlr->bus_num >= 0) {
|
|
/* devices with a fixed bus num must check-in with the num */
|
|
mutex_lock(&board_lock);
|
|
id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
|
|
ctlr->bus_num + 1, GFP_KERNEL);
|
|
mutex_unlock(&board_lock);
|
|
if (WARN(id < 0, "couldn't get idr"))
|
|
return id == -ENOSPC ? -EBUSY : id;
|
|
ctlr->bus_num = id;
|
|
} else if (ctlr->dev.of_node) {
|
|
/* allocate dynamic bus number using Linux idr */
|
|
id = of_alias_get_id(ctlr->dev.of_node, "spi");
|
|
if (id >= 0) {
|
|
ctlr->bus_num = id;
|
|
mutex_lock(&board_lock);
|
|
id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num,
|
|
ctlr->bus_num + 1, GFP_KERNEL);
|
|
mutex_unlock(&board_lock);
|
|
if (WARN(id < 0, "couldn't get idr"))
|
|
return id == -ENOSPC ? -EBUSY : id;
|
|
}
|
|
}
|
|
if (ctlr->bus_num < 0) {
|
|
first_dynamic = of_alias_get_highest_id("spi");
|
|
if (first_dynamic < 0)
|
|
first_dynamic = 0;
|
|
else
|
|
first_dynamic++;
|
|
|
|
mutex_lock(&board_lock);
|
|
id = idr_alloc(&spi_master_idr, ctlr, first_dynamic,
|
|
0, GFP_KERNEL);
|
|
mutex_unlock(&board_lock);
|
|
if (WARN(id < 0, "couldn't get idr"))
|
|
return id;
|
|
ctlr->bus_num = id;
|
|
}
|
|
INIT_LIST_HEAD(&ctlr->queue);
|
|
spin_lock_init(&ctlr->queue_lock);
|
|
spin_lock_init(&ctlr->bus_lock_spinlock);
|
|
mutex_init(&ctlr->bus_lock_mutex);
|
|
mutex_init(&ctlr->io_mutex);
|
|
ctlr->bus_lock_flag = 0;
|
|
init_completion(&ctlr->xfer_completion);
|
|
if (!ctlr->max_dma_len)
|
|
ctlr->max_dma_len = INT_MAX;
|
|
|
|
/* register the device, then userspace will see it.
|
|
* registration fails if the bus ID is in use.
|
|
*/
|
|
dev_set_name(&ctlr->dev, "spi%u", ctlr->bus_num);
|
|
|
|
if (!spi_controller_is_slave(ctlr)) {
|
|
if (ctlr->use_gpio_descriptors) {
|
|
status = spi_get_gpio_descs(ctlr);
|
|
if (status)
|
|
return status;
|
|
/*
|
|
* A controller using GPIO descriptors always
|
|
* supports SPI_CS_HIGH if need be.
|
|
*/
|
|
ctlr->mode_bits |= SPI_CS_HIGH;
|
|
} else {
|
|
/* Legacy code path for GPIOs from DT */
|
|
status = of_spi_get_gpio_numbers(ctlr);
|
|
if (status)
|
|
return status;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Even if it's just one always-selected device, there must
|
|
* be at least one chipselect.
|
|
*/
|
|
if (!ctlr->num_chipselect)
|
|
return -EINVAL;
|
|
|
|
status = device_add(&ctlr->dev);
|
|
if (status < 0) {
|
|
/* free bus id */
|
|
mutex_lock(&board_lock);
|
|
idr_remove(&spi_master_idr, ctlr->bus_num);
|
|
mutex_unlock(&board_lock);
|
|
goto done;
|
|
}
|
|
dev_dbg(dev, "registered %s %s\n",
|
|
spi_controller_is_slave(ctlr) ? "slave" : "master",
|
|
dev_name(&ctlr->dev));
|
|
|
|
/*
|
|
* If we're using a queued driver, start the queue. Note that we don't
|
|
* need the queueing logic if the driver is only supporting high-level
|
|
* memory operations.
|
|
*/
|
|
if (ctlr->transfer) {
|
|
dev_info(dev, "controller is unqueued, this is deprecated\n");
|
|
} else if (ctlr->transfer_one || ctlr->transfer_one_message) {
|
|
status = spi_controller_initialize_queue(ctlr);
|
|
if (status) {
|
|
device_del(&ctlr->dev);
|
|
/* free bus id */
|
|
mutex_lock(&board_lock);
|
|
idr_remove(&spi_master_idr, ctlr->bus_num);
|
|
mutex_unlock(&board_lock);
|
|
goto done;
|
|
}
|
|
}
|
|
/* add statistics */
|
|
spin_lock_init(&ctlr->statistics.lock);
|
|
|
|
mutex_lock(&board_lock);
|
|
list_add_tail(&ctlr->list, &spi_controller_list);
|
|
list_for_each_entry(bi, &board_list, list)
|
|
spi_match_controller_to_boardinfo(ctlr, &bi->board_info);
|
|
mutex_unlock(&board_lock);
|
|
|
|
/* Register devices from the device tree and ACPI */
|
|
of_register_spi_devices(ctlr);
|
|
acpi_register_spi_devices(ctlr);
|
|
done:
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_register_controller);
|
|
|
|
static void devm_spi_unregister(struct device *dev, void *res)
|
|
{
|
|
spi_unregister_controller(*(struct spi_controller **)res);
|
|
}
|
|
|
|
/**
|
|
* devm_spi_register_controller - register managed SPI master or slave
|
|
* controller
|
|
* @dev: device managing SPI controller
|
|
* @ctlr: initialized controller, originally from spi_alloc_master() or
|
|
* spi_alloc_slave()
|
|
* Context: can sleep
|
|
*
|
|
* Register a SPI device as with spi_register_controller() which will
|
|
* automatically be unregistered and freed.
|
|
*
|
|
* Return: zero on success, else a negative error code.
|
|
*/
|
|
int devm_spi_register_controller(struct device *dev,
|
|
struct spi_controller *ctlr)
|
|
{
|
|
struct spi_controller **ptr;
|
|
int ret;
|
|
|
|
ptr = devres_alloc(devm_spi_unregister, sizeof(*ptr), GFP_KERNEL);
|
|
if (!ptr)
|
|
return -ENOMEM;
|
|
|
|
ret = spi_register_controller(ctlr);
|
|
if (!ret) {
|
|
*ptr = ctlr;
|
|
devres_add(dev, ptr);
|
|
} else {
|
|
devres_free(ptr);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_spi_register_controller);
|
|
|
|
static int __unregister(struct device *dev, void *null)
|
|
{
|
|
spi_unregister_device(to_spi_device(dev));
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* spi_unregister_controller - unregister SPI master or slave controller
|
|
* @ctlr: the controller being unregistered
|
|
* Context: can sleep
|
|
*
|
|
* This call is used only by SPI controller drivers, which are the
|
|
* only ones directly touching chip registers.
|
|
*
|
|
* This must be called from context that can sleep.
|
|
*
|
|
* Note that this function also drops a reference to the controller.
|
|
*/
|
|
void spi_unregister_controller(struct spi_controller *ctlr)
|
|
{
|
|
struct spi_controller *found;
|
|
int id = ctlr->bus_num;
|
|
|
|
/* First make sure that this controller was ever added */
|
|
mutex_lock(&board_lock);
|
|
found = idr_find(&spi_master_idr, id);
|
|
mutex_unlock(&board_lock);
|
|
if (ctlr->queued) {
|
|
if (spi_destroy_queue(ctlr))
|
|
dev_err(&ctlr->dev, "queue remove failed\n");
|
|
}
|
|
mutex_lock(&board_lock);
|
|
list_del(&ctlr->list);
|
|
mutex_unlock(&board_lock);
|
|
|
|
device_for_each_child(&ctlr->dev, NULL, __unregister);
|
|
device_unregister(&ctlr->dev);
|
|
/* free bus id */
|
|
mutex_lock(&board_lock);
|
|
if (found == ctlr)
|
|
idr_remove(&spi_master_idr, id);
|
|
mutex_unlock(&board_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_unregister_controller);
|
|
|
|
int spi_controller_suspend(struct spi_controller *ctlr)
|
|
{
|
|
int ret;
|
|
|
|
/* Basically no-ops for non-queued controllers */
|
|
if (!ctlr->queued)
|
|
return 0;
|
|
|
|
ret = spi_stop_queue(ctlr);
|
|
if (ret)
|
|
dev_err(&ctlr->dev, "queue stop failed\n");
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_controller_suspend);
|
|
|
|
int spi_controller_resume(struct spi_controller *ctlr)
|
|
{
|
|
int ret;
|
|
|
|
if (!ctlr->queued)
|
|
return 0;
|
|
|
|
ret = spi_start_queue(ctlr);
|
|
if (ret)
|
|
dev_err(&ctlr->dev, "queue restart failed\n");
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_controller_resume);
|
|
|
|
static int __spi_controller_match(struct device *dev, const void *data)
|
|
{
|
|
struct spi_controller *ctlr;
|
|
const u16 *bus_num = data;
|
|
|
|
ctlr = container_of(dev, struct spi_controller, dev);
|
|
return ctlr->bus_num == *bus_num;
|
|
}
|
|
|
|
/**
|
|
* spi_busnum_to_master - look up master associated with bus_num
|
|
* @bus_num: the master's bus number
|
|
* Context: can sleep
|
|
*
|
|
* This call may be used with devices that are registered after
|
|
* arch init time. It returns a refcounted pointer to the relevant
|
|
* spi_controller (which the caller must release), or NULL if there is
|
|
* no such master registered.
|
|
*
|
|
* Return: the SPI master structure on success, else NULL.
|
|
*/
|
|
struct spi_controller *spi_busnum_to_master(u16 bus_num)
|
|
{
|
|
struct device *dev;
|
|
struct spi_controller *ctlr = NULL;
|
|
|
|
dev = class_find_device(&spi_master_class, NULL, &bus_num,
|
|
__spi_controller_match);
|
|
if (dev)
|
|
ctlr = container_of(dev, struct spi_controller, dev);
|
|
/* reference got in class_find_device */
|
|
return ctlr;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_busnum_to_master);
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
/* Core methods for SPI resource management */
|
|
|
|
/**
|
|
* spi_res_alloc - allocate a spi resource that is life-cycle managed
|
|
* during the processing of a spi_message while using
|
|
* spi_transfer_one
|
|
* @spi: the spi device for which we allocate memory
|
|
* @release: the release code to execute for this resource
|
|
* @size: size to alloc and return
|
|
* @gfp: GFP allocation flags
|
|
*
|
|
* Return: the pointer to the allocated data
|
|
*
|
|
* This may get enhanced in the future to allocate from a memory pool
|
|
* of the @spi_device or @spi_controller to avoid repeated allocations.
|
|
*/
|
|
void *spi_res_alloc(struct spi_device *spi,
|
|
spi_res_release_t release,
|
|
size_t size, gfp_t gfp)
|
|
{
|
|
struct spi_res *sres;
|
|
|
|
sres = kzalloc(sizeof(*sres) + size, gfp);
|
|
if (!sres)
|
|
return NULL;
|
|
|
|
INIT_LIST_HEAD(&sres->entry);
|
|
sres->release = release;
|
|
|
|
return sres->data;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_res_alloc);
|
|
|
|
/**
|
|
* spi_res_free - free an spi resource
|
|
* @res: pointer to the custom data of a resource
|
|
*
|
|
*/
|
|
void spi_res_free(void *res)
|
|
{
|
|
struct spi_res *sres = container_of(res, struct spi_res, data);
|
|
|
|
if (!res)
|
|
return;
|
|
|
|
WARN_ON(!list_empty(&sres->entry));
|
|
kfree(sres);
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_res_free);
|
|
|
|
/**
|
|
* spi_res_add - add a spi_res to the spi_message
|
|
* @message: the spi message
|
|
* @res: the spi_resource
|
|
*/
|
|
void spi_res_add(struct spi_message *message, void *res)
|
|
{
|
|
struct spi_res *sres = container_of(res, struct spi_res, data);
|
|
|
|
WARN_ON(!list_empty(&sres->entry));
|
|
list_add_tail(&sres->entry, &message->resources);
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_res_add);
|
|
|
|
/**
|
|
* spi_res_release - release all spi resources for this message
|
|
* @ctlr: the @spi_controller
|
|
* @message: the @spi_message
|
|
*/
|
|
void spi_res_release(struct spi_controller *ctlr, struct spi_message *message)
|
|
{
|
|
struct spi_res *res, *tmp;
|
|
|
|
list_for_each_entry_safe_reverse(res, tmp, &message->resources, entry) {
|
|
if (res->release)
|
|
res->release(ctlr, message, res->data);
|
|
|
|
list_del(&res->entry);
|
|
|
|
kfree(res);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_res_release);
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
/* Core methods for spi_message alterations */
|
|
|
|
static void __spi_replace_transfers_release(struct spi_controller *ctlr,
|
|
struct spi_message *msg,
|
|
void *res)
|
|
{
|
|
struct spi_replaced_transfers *rxfer = res;
|
|
size_t i;
|
|
|
|
/* call extra callback if requested */
|
|
if (rxfer->release)
|
|
rxfer->release(ctlr, msg, res);
|
|
|
|
/* insert replaced transfers back into the message */
|
|
list_splice(&rxfer->replaced_transfers, rxfer->replaced_after);
|
|
|
|
/* remove the formerly inserted entries */
|
|
for (i = 0; i < rxfer->inserted; i++)
|
|
list_del(&rxfer->inserted_transfers[i].transfer_list);
|
|
}
|
|
|
|
/**
|
|
* spi_replace_transfers - replace transfers with several transfers
|
|
* and register change with spi_message.resources
|
|
* @msg: the spi_message we work upon
|
|
* @xfer_first: the first spi_transfer we want to replace
|
|
* @remove: number of transfers to remove
|
|
* @insert: the number of transfers we want to insert instead
|
|
* @release: extra release code necessary in some circumstances
|
|
* @extradatasize: extra data to allocate (with alignment guarantees
|
|
* of struct @spi_transfer)
|
|
* @gfp: gfp flags
|
|
*
|
|
* Returns: pointer to @spi_replaced_transfers,
|
|
* PTR_ERR(...) in case of errors.
|
|
*/
|
|
struct spi_replaced_transfers *spi_replace_transfers(
|
|
struct spi_message *msg,
|
|
struct spi_transfer *xfer_first,
|
|
size_t remove,
|
|
size_t insert,
|
|
spi_replaced_release_t release,
|
|
size_t extradatasize,
|
|
gfp_t gfp)
|
|
{
|
|
struct spi_replaced_transfers *rxfer;
|
|
struct spi_transfer *xfer;
|
|
size_t i;
|
|
|
|
/* allocate the structure using spi_res */
|
|
rxfer = spi_res_alloc(msg->spi, __spi_replace_transfers_release,
|
|
struct_size(rxfer, inserted_transfers, insert)
|
|
+ extradatasize,
|
|
gfp);
|
|
if (!rxfer)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/* the release code to invoke before running the generic release */
|
|
rxfer->release = release;
|
|
|
|
/* assign extradata */
|
|
if (extradatasize)
|
|
rxfer->extradata =
|
|
&rxfer->inserted_transfers[insert];
|
|
|
|
/* init the replaced_transfers list */
|
|
INIT_LIST_HEAD(&rxfer->replaced_transfers);
|
|
|
|
/* assign the list_entry after which we should reinsert
|
|
* the @replaced_transfers - it may be spi_message.messages!
|
|
*/
|
|
rxfer->replaced_after = xfer_first->transfer_list.prev;
|
|
|
|
/* remove the requested number of transfers */
|
|
for (i = 0; i < remove; i++) {
|
|
/* if the entry after replaced_after it is msg->transfers
|
|
* then we have been requested to remove more transfers
|
|
* than are in the list
|
|
*/
|
|
if (rxfer->replaced_after->next == &msg->transfers) {
|
|
dev_err(&msg->spi->dev,
|
|
"requested to remove more spi_transfers than are available\n");
|
|
/* insert replaced transfers back into the message */
|
|
list_splice(&rxfer->replaced_transfers,
|
|
rxfer->replaced_after);
|
|
|
|
/* free the spi_replace_transfer structure */
|
|
spi_res_free(rxfer);
|
|
|
|
/* and return with an error */
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
/* remove the entry after replaced_after from list of
|
|
* transfers and add it to list of replaced_transfers
|
|
*/
|
|
list_move_tail(rxfer->replaced_after->next,
|
|
&rxfer->replaced_transfers);
|
|
}
|
|
|
|
/* create copy of the given xfer with identical settings
|
|
* based on the first transfer to get removed
|
|
*/
|
|
for (i = 0; i < insert; i++) {
|
|
/* we need to run in reverse order */
|
|
xfer = &rxfer->inserted_transfers[insert - 1 - i];
|
|
|
|
/* copy all spi_transfer data */
|
|
memcpy(xfer, xfer_first, sizeof(*xfer));
|
|
|
|
/* add to list */
|
|
list_add(&xfer->transfer_list, rxfer->replaced_after);
|
|
|
|
/* clear cs_change and delay for all but the last */
|
|
if (i) {
|
|
xfer->cs_change = false;
|
|
xfer->delay_usecs = 0;
|
|
xfer->delay.value = 0;
|
|
}
|
|
}
|
|
|
|
/* set up inserted */
|
|
rxfer->inserted = insert;
|
|
|
|
/* and register it with spi_res/spi_message */
|
|
spi_res_add(msg, rxfer);
|
|
|
|
return rxfer;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_replace_transfers);
|
|
|
|
static int __spi_split_transfer_maxsize(struct spi_controller *ctlr,
|
|
struct spi_message *msg,
|
|
struct spi_transfer **xferp,
|
|
size_t maxsize,
|
|
gfp_t gfp)
|
|
{
|
|
struct spi_transfer *xfer = *xferp, *xfers;
|
|
struct spi_replaced_transfers *srt;
|
|
size_t offset;
|
|
size_t count, i;
|
|
|
|
/* calculate how many we have to replace */
|
|
count = DIV_ROUND_UP(xfer->len, maxsize);
|
|
|
|
/* create replacement */
|
|
srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp);
|
|
if (IS_ERR(srt))
|
|
return PTR_ERR(srt);
|
|
xfers = srt->inserted_transfers;
|
|
|
|
/* now handle each of those newly inserted spi_transfers
|
|
* note that the replacements spi_transfers all are preset
|
|
* to the same values as *xferp, so tx_buf, rx_buf and len
|
|
* are all identical (as well as most others)
|
|
* so we just have to fix up len and the pointers.
|
|
*
|
|
* this also includes support for the depreciated
|
|
* spi_message.is_dma_mapped interface
|
|
*/
|
|
|
|
/* the first transfer just needs the length modified, so we
|
|
* run it outside the loop
|
|
*/
|
|
xfers[0].len = min_t(size_t, maxsize, xfer[0].len);
|
|
|
|
/* all the others need rx_buf/tx_buf also set */
|
|
for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) {
|
|
/* update rx_buf, tx_buf and dma */
|
|
if (xfers[i].rx_buf)
|
|
xfers[i].rx_buf += offset;
|
|
if (xfers[i].rx_dma)
|
|
xfers[i].rx_dma += offset;
|
|
if (xfers[i].tx_buf)
|
|
xfers[i].tx_buf += offset;
|
|
if (xfers[i].tx_dma)
|
|
xfers[i].tx_dma += offset;
|
|
|
|
/* update length */
|
|
xfers[i].len = min(maxsize, xfers[i].len - offset);
|
|
}
|
|
|
|
/* we set up xferp to the last entry we have inserted,
|
|
* so that we skip those already split transfers
|
|
*/
|
|
*xferp = &xfers[count - 1];
|
|
|
|
/* increment statistics counters */
|
|
SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
|
|
transfers_split_maxsize);
|
|
SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics,
|
|
transfers_split_maxsize);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* spi_split_tranfers_maxsize - split spi transfers into multiple transfers
|
|
* when an individual transfer exceeds a
|
|
* certain size
|
|
* @ctlr: the @spi_controller for this transfer
|
|
* @msg: the @spi_message to transform
|
|
* @maxsize: the maximum when to apply this
|
|
* @gfp: GFP allocation flags
|
|
*
|
|
* Return: status of transformation
|
|
*/
|
|
int spi_split_transfers_maxsize(struct spi_controller *ctlr,
|
|
struct spi_message *msg,
|
|
size_t maxsize,
|
|
gfp_t gfp)
|
|
{
|
|
struct spi_transfer *xfer;
|
|
int ret;
|
|
|
|
/* iterate over the transfer_list,
|
|
* but note that xfer is advanced to the last transfer inserted
|
|
* to avoid checking sizes again unnecessarily (also xfer does
|
|
* potentiall belong to a different list by the time the
|
|
* replacement has happened
|
|
*/
|
|
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
|
|
if (xfer->len > maxsize) {
|
|
ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer,
|
|
maxsize, gfp);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize);
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
/* Core methods for SPI controller protocol drivers. Some of the
|
|
* other core methods are currently defined as inline functions.
|
|
*/
|
|
|
|
static int __spi_validate_bits_per_word(struct spi_controller *ctlr,
|
|
u8 bits_per_word)
|
|
{
|
|
if (ctlr->bits_per_word_mask) {
|
|
/* Only 32 bits fit in the mask */
|
|
if (bits_per_word > 32)
|
|
return -EINVAL;
|
|
if (!(ctlr->bits_per_word_mask & SPI_BPW_MASK(bits_per_word)))
|
|
return -EINVAL;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* spi_setup - setup SPI mode and clock rate
|
|
* @spi: the device whose settings are being modified
|
|
* Context: can sleep, and no requests are queued to the device
|
|
*
|
|
* SPI protocol drivers may need to update the transfer mode if the
|
|
* device doesn't work with its default. They may likewise need
|
|
* to update clock rates or word sizes from initial values. This function
|
|
* changes those settings, and must be called from a context that can sleep.
|
|
* Except for SPI_CS_HIGH, which takes effect immediately, the changes take
|
|
* effect the next time the device is selected and data is transferred to
|
|
* or from it. When this function returns, the spi device is deselected.
|
|
*
|
|
* Note that this call will fail if the protocol driver specifies an option
|
|
* that the underlying controller or its driver does not support. For
|
|
* example, not all hardware supports wire transfers using nine bit words,
|
|
* LSB-first wire encoding, or active-high chipselects.
|
|
*
|
|
* Return: zero on success, else a negative error code.
|
|
*/
|
|
int spi_setup(struct spi_device *spi)
|
|
{
|
|
unsigned bad_bits, ugly_bits;
|
|
int status;
|
|
|
|
/* check mode to prevent that DUAL and QUAD set at the same time
|
|
*/
|
|
if (((spi->mode & SPI_TX_DUAL) && (spi->mode & SPI_TX_QUAD)) ||
|
|
((spi->mode & SPI_RX_DUAL) && (spi->mode & SPI_RX_QUAD))) {
|
|
dev_err(&spi->dev,
|
|
"setup: can not select dual and quad at the same time\n");
|
|
return -EINVAL;
|
|
}
|
|
/* if it is SPI_3WIRE mode, DUAL and QUAD should be forbidden
|
|
*/
|
|
if ((spi->mode & SPI_3WIRE) && (spi->mode &
|
|
(SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
|
|
SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))
|
|
return -EINVAL;
|
|
/* help drivers fail *cleanly* when they need options
|
|
* that aren't supported with their current controller
|
|
* SPI_CS_WORD has a fallback software implementation,
|
|
* so it is ignored here.
|
|
*/
|
|
bad_bits = spi->mode & ~(spi->controller->mode_bits | SPI_CS_WORD);
|
|
/* nothing prevents from working with active-high CS in case if it
|
|
* is driven by GPIO.
|
|
*/
|
|
if (gpio_is_valid(spi->cs_gpio))
|
|
bad_bits &= ~SPI_CS_HIGH;
|
|
ugly_bits = bad_bits &
|
|
(SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL |
|
|
SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL);
|
|
if (ugly_bits) {
|
|
dev_warn(&spi->dev,
|
|
"setup: ignoring unsupported mode bits %x\n",
|
|
ugly_bits);
|
|
spi->mode &= ~ugly_bits;
|
|
bad_bits &= ~ugly_bits;
|
|
}
|
|
if (bad_bits) {
|
|
dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
|
|
bad_bits);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!spi->bits_per_word)
|
|
spi->bits_per_word = 8;
|
|
|
|
status = __spi_validate_bits_per_word(spi->controller,
|
|
spi->bits_per_word);
|
|
if (status)
|
|
return status;
|
|
|
|
if (!spi->max_speed_hz)
|
|
spi->max_speed_hz = spi->controller->max_speed_hz;
|
|
|
|
if (spi->controller->setup)
|
|
status = spi->controller->setup(spi);
|
|
|
|
if (spi->controller->auto_runtime_pm && spi->controller->set_cs) {
|
|
status = pm_runtime_get_sync(spi->controller->dev.parent);
|
|
if (status < 0) {
|
|
pm_runtime_put_noidle(spi->controller->dev.parent);
|
|
dev_err(&spi->controller->dev, "Failed to power device: %d\n",
|
|
status);
|
|
return status;
|
|
}
|
|
|
|
/*
|
|
* We do not want to return positive value from pm_runtime_get,
|
|
* there are many instances of devices calling spi_setup() and
|
|
* checking for a non-zero return value instead of a negative
|
|
* return value.
|
|
*/
|
|
status = 0;
|
|
|
|
spi_set_cs(spi, false);
|
|
pm_runtime_mark_last_busy(spi->controller->dev.parent);
|
|
pm_runtime_put_autosuspend(spi->controller->dev.parent);
|
|
} else {
|
|
spi_set_cs(spi, false);
|
|
}
|
|
|
|
if (spi->rt && !spi->controller->rt) {
|
|
spi->controller->rt = true;
|
|
spi_set_thread_rt(spi->controller);
|
|
}
|
|
|
|
dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n",
|
|
(int) (spi->mode & (SPI_CPOL | SPI_CPHA)),
|
|
(spi->mode & SPI_CS_HIGH) ? "cs_high, " : "",
|
|
(spi->mode & SPI_LSB_FIRST) ? "lsb, " : "",
|
|
(spi->mode & SPI_3WIRE) ? "3wire, " : "",
|
|
(spi->mode & SPI_LOOP) ? "loopback, " : "",
|
|
spi->bits_per_word, spi->max_speed_hz,
|
|
status);
|
|
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_setup);
|
|
|
|
/**
|
|
* spi_set_cs_timing - configure CS setup, hold, and inactive delays
|
|
* @spi: the device that requires specific CS timing configuration
|
|
* @setup: CS setup time specified via @spi_delay
|
|
* @hold: CS hold time specified via @spi_delay
|
|
* @inactive: CS inactive delay between transfers specified via @spi_delay
|
|
*
|
|
* Return: zero on success, else a negative error code.
|
|
*/
|
|
int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup,
|
|
struct spi_delay *hold, struct spi_delay *inactive)
|
|
{
|
|
size_t len;
|
|
|
|
if (spi->controller->set_cs_timing)
|
|
return spi->controller->set_cs_timing(spi, setup, hold,
|
|
inactive);
|
|
|
|
if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) ||
|
|
(hold && hold->unit == SPI_DELAY_UNIT_SCK) ||
|
|
(inactive && inactive->unit == SPI_DELAY_UNIT_SCK)) {
|
|
dev_err(&spi->dev,
|
|
"Clock-cycle delays for CS not supported in SW mode\n");
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
len = sizeof(struct spi_delay);
|
|
|
|
/* copy delays to controller */
|
|
if (setup)
|
|
memcpy(&spi->controller->cs_setup, setup, len);
|
|
else
|
|
memset(&spi->controller->cs_setup, 0, len);
|
|
|
|
if (hold)
|
|
memcpy(&spi->controller->cs_hold, hold, len);
|
|
else
|
|
memset(&spi->controller->cs_hold, 0, len);
|
|
|
|
if (inactive)
|
|
memcpy(&spi->controller->cs_inactive, inactive, len);
|
|
else
|
|
memset(&spi->controller->cs_inactive, 0, len);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_set_cs_timing);
|
|
|
|
static int _spi_xfer_word_delay_update(struct spi_transfer *xfer,
|
|
struct spi_device *spi)
|
|
{
|
|
int delay1, delay2;
|
|
|
|
delay1 = spi_delay_to_ns(&xfer->word_delay, xfer);
|
|
if (delay1 < 0)
|
|
return delay1;
|
|
|
|
delay2 = spi_delay_to_ns(&spi->word_delay, xfer);
|
|
if (delay2 < 0)
|
|
return delay2;
|
|
|
|
if (delay1 < delay2)
|
|
memcpy(&xfer->word_delay, &spi->word_delay,
|
|
sizeof(xfer->word_delay));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __spi_validate(struct spi_device *spi, struct spi_message *message)
|
|
{
|
|
struct spi_controller *ctlr = spi->controller;
|
|
struct spi_transfer *xfer;
|
|
int w_size;
|
|
|
|
if (list_empty(&message->transfers))
|
|
return -EINVAL;
|
|
|
|
/* If an SPI controller does not support toggling the CS line on each
|
|
* transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO
|
|
* for the CS line, we can emulate the CS-per-word hardware function by
|
|
* splitting transfers into one-word transfers and ensuring that
|
|
* cs_change is set for each transfer.
|
|
*/
|
|
if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
|
|
spi->cs_gpiod ||
|
|
gpio_is_valid(spi->cs_gpio))) {
|
|
size_t maxsize;
|
|
int ret;
|
|
|
|
maxsize = (spi->bits_per_word + 7) / 8;
|
|
|
|
/* spi_split_transfers_maxsize() requires message->spi */
|
|
message->spi = spi;
|
|
|
|
ret = spi_split_transfers_maxsize(ctlr, message, maxsize,
|
|
GFP_KERNEL);
|
|
if (ret)
|
|
return ret;
|
|
|
|
list_for_each_entry(xfer, &message->transfers, transfer_list) {
|
|
/* don't change cs_change on the last entry in the list */
|
|
if (list_is_last(&xfer->transfer_list, &message->transfers))
|
|
break;
|
|
xfer->cs_change = 1;
|
|
}
|
|
}
|
|
|
|
/* Half-duplex links include original MicroWire, and ones with
|
|
* only one data pin like SPI_3WIRE (switches direction) or where
|
|
* either MOSI or MISO is missing. They can also be caused by
|
|
* software limitations.
|
|
*/
|
|
if ((ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX) ||
|
|
(spi->mode & SPI_3WIRE)) {
|
|
unsigned flags = ctlr->flags;
|
|
|
|
list_for_each_entry(xfer, &message->transfers, transfer_list) {
|
|
if (xfer->rx_buf && xfer->tx_buf)
|
|
return -EINVAL;
|
|
if ((flags & SPI_CONTROLLER_NO_TX) && xfer->tx_buf)
|
|
return -EINVAL;
|
|
if ((flags & SPI_CONTROLLER_NO_RX) && xfer->rx_buf)
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Set transfer bits_per_word and max speed as spi device default if
|
|
* it is not set for this transfer.
|
|
* Set transfer tx_nbits and rx_nbits as single transfer default
|
|
* (SPI_NBITS_SINGLE) if it is not set for this transfer.
|
|
* Ensure transfer word_delay is at least as long as that required by
|
|
* device itself.
|
|
*/
|
|
message->frame_length = 0;
|
|
list_for_each_entry(xfer, &message->transfers, transfer_list) {
|
|
xfer->effective_speed_hz = 0;
|
|
message->frame_length += xfer->len;
|
|
if (!xfer->bits_per_word)
|
|
xfer->bits_per_word = spi->bits_per_word;
|
|
|
|
if (!xfer->speed_hz)
|
|
xfer->speed_hz = spi->max_speed_hz;
|
|
|
|
if (ctlr->max_speed_hz && xfer->speed_hz > ctlr->max_speed_hz)
|
|
xfer->speed_hz = ctlr->max_speed_hz;
|
|
|
|
if (__spi_validate_bits_per_word(ctlr, xfer->bits_per_word))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* SPI transfer length should be multiple of SPI word size
|
|
* where SPI word size should be power-of-two multiple
|
|
*/
|
|
if (xfer->bits_per_word <= 8)
|
|
w_size = 1;
|
|
else if (xfer->bits_per_word <= 16)
|
|
w_size = 2;
|
|
else
|
|
w_size = 4;
|
|
|
|
/* No partial transfers accepted */
|
|
if (xfer->len % w_size)
|
|
return -EINVAL;
|
|
|
|
if (xfer->speed_hz && ctlr->min_speed_hz &&
|
|
xfer->speed_hz < ctlr->min_speed_hz)
|
|
return -EINVAL;
|
|
|
|
if (xfer->tx_buf && !xfer->tx_nbits)
|
|
xfer->tx_nbits = SPI_NBITS_SINGLE;
|
|
if (xfer->rx_buf && !xfer->rx_nbits)
|
|
xfer->rx_nbits = SPI_NBITS_SINGLE;
|
|
/* check transfer tx/rx_nbits:
|
|
* 1. check the value matches one of single, dual and quad
|
|
* 2. check tx/rx_nbits match the mode in spi_device
|
|
*/
|
|
if (xfer->tx_buf) {
|
|
if (xfer->tx_nbits != SPI_NBITS_SINGLE &&
|
|
xfer->tx_nbits != SPI_NBITS_DUAL &&
|
|
xfer->tx_nbits != SPI_NBITS_QUAD)
|
|
return -EINVAL;
|
|
if ((xfer->tx_nbits == SPI_NBITS_DUAL) &&
|
|
!(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD)))
|
|
return -EINVAL;
|
|
if ((xfer->tx_nbits == SPI_NBITS_QUAD) &&
|
|
!(spi->mode & SPI_TX_QUAD))
|
|
return -EINVAL;
|
|
}
|
|
/* check transfer rx_nbits */
|
|
if (xfer->rx_buf) {
|
|
if (xfer->rx_nbits != SPI_NBITS_SINGLE &&
|
|
xfer->rx_nbits != SPI_NBITS_DUAL &&
|
|
xfer->rx_nbits != SPI_NBITS_QUAD)
|
|
return -EINVAL;
|
|
if ((xfer->rx_nbits == SPI_NBITS_DUAL) &&
|
|
!(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD)))
|
|
return -EINVAL;
|
|
if ((xfer->rx_nbits == SPI_NBITS_QUAD) &&
|
|
!(spi->mode & SPI_RX_QUAD))
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (_spi_xfer_word_delay_update(xfer, spi))
|
|
return -EINVAL;
|
|
}
|
|
|
|
message->status = -EINPROGRESS;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int __spi_async(struct spi_device *spi, struct spi_message *message)
|
|
{
|
|
struct spi_controller *ctlr = spi->controller;
|
|
struct spi_transfer *xfer;
|
|
|
|
/*
|
|
* Some controllers do not support doing regular SPI transfers. Return
|
|
* ENOTSUPP when this is the case.
|
|
*/
|
|
if (!ctlr->transfer)
|
|
return -ENOTSUPP;
|
|
|
|
message->spi = spi;
|
|
|
|
SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async);
|
|
SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async);
|
|
|
|
trace_spi_message_submit(message);
|
|
|
|
if (!ctlr->ptp_sts_supported) {
|
|
list_for_each_entry(xfer, &message->transfers, transfer_list) {
|
|
xfer->ptp_sts_word_pre = 0;
|
|
ptp_read_system_prets(xfer->ptp_sts);
|
|
}
|
|
}
|
|
|
|
return ctlr->transfer(spi, message);
|
|
}
|
|
|
|
/**
|
|
* spi_async - asynchronous SPI transfer
|
|
* @spi: device with which data will be exchanged
|
|
* @message: describes the data transfers, including completion callback
|
|
* Context: any (irqs may be blocked, etc)
|
|
*
|
|
* This call may be used in_irq and other contexts which can't sleep,
|
|
* as well as from task contexts which can sleep.
|
|
*
|
|
* The completion callback is invoked in a context which can't sleep.
|
|
* Before that invocation, the value of message->status is undefined.
|
|
* When the callback is issued, message->status holds either zero (to
|
|
* indicate complete success) or a negative error code. After that
|
|
* callback returns, the driver which issued the transfer request may
|
|
* deallocate the associated memory; it's no longer in use by any SPI
|
|
* core or controller driver code.
|
|
*
|
|
* Note that although all messages to a spi_device are handled in
|
|
* FIFO order, messages may go to different devices in other orders.
|
|
* Some device might be higher priority, or have various "hard" access
|
|
* time requirements, for example.
|
|
*
|
|
* On detection of any fault during the transfer, processing of
|
|
* the entire message is aborted, and the device is deselected.
|
|
* Until returning from the associated message completion callback,
|
|
* no other spi_message queued to that device will be processed.
|
|
* (This rule applies equally to all the synchronous transfer calls,
|
|
* which are wrappers around this core asynchronous primitive.)
|
|
*
|
|
* Return: zero on success, else a negative error code.
|
|
*/
|
|
int spi_async(struct spi_device *spi, struct spi_message *message)
|
|
{
|
|
struct spi_controller *ctlr = spi->controller;
|
|
int ret;
|
|
unsigned long flags;
|
|
|
|
ret = __spi_validate(spi, message);
|
|
if (ret != 0)
|
|
return ret;
|
|
|
|
spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
|
|
|
|
if (ctlr->bus_lock_flag)
|
|
ret = -EBUSY;
|
|
else
|
|
ret = __spi_async(spi, message);
|
|
|
|
spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_async);
|
|
|
|
/**
|
|
* spi_async_locked - version of spi_async with exclusive bus usage
|
|
* @spi: device with which data will be exchanged
|
|
* @message: describes the data transfers, including completion callback
|
|
* Context: any (irqs may be blocked, etc)
|
|
*
|
|
* This call may be used in_irq and other contexts which can't sleep,
|
|
* as well as from task contexts which can sleep.
|
|
*
|
|
* The completion callback is invoked in a context which can't sleep.
|
|
* Before that invocation, the value of message->status is undefined.
|
|
* When the callback is issued, message->status holds either zero (to
|
|
* indicate complete success) or a negative error code. After that
|
|
* callback returns, the driver which issued the transfer request may
|
|
* deallocate the associated memory; it's no longer in use by any SPI
|
|
* core or controller driver code.
|
|
*
|
|
* Note that although all messages to a spi_device are handled in
|
|
* FIFO order, messages may go to different devices in other orders.
|
|
* Some device might be higher priority, or have various "hard" access
|
|
* time requirements, for example.
|
|
*
|
|
* On detection of any fault during the transfer, processing of
|
|
* the entire message is aborted, and the device is deselected.
|
|
* Until returning from the associated message completion callback,
|
|
* no other spi_message queued to that device will be processed.
|
|
* (This rule applies equally to all the synchronous transfer calls,
|
|
* which are wrappers around this core asynchronous primitive.)
|
|
*
|
|
* Return: zero on success, else a negative error code.
|
|
*/
|
|
int spi_async_locked(struct spi_device *spi, struct spi_message *message)
|
|
{
|
|
struct spi_controller *ctlr = spi->controller;
|
|
int ret;
|
|
unsigned long flags;
|
|
|
|
ret = __spi_validate(spi, message);
|
|
if (ret != 0)
|
|
return ret;
|
|
|
|
spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
|
|
|
|
ret = __spi_async(spi, message);
|
|
|
|
spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
|
|
|
|
return ret;
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_async_locked);
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
/* Utility methods for SPI protocol drivers, layered on
|
|
* top of the core. Some other utility methods are defined as
|
|
* inline functions.
|
|
*/
|
|
|
|
static void spi_complete(void *arg)
|
|
{
|
|
complete(arg);
|
|
}
|
|
|
|
static int __spi_sync(struct spi_device *spi, struct spi_message *message)
|
|
{
|
|
DECLARE_COMPLETION_ONSTACK(done);
|
|
int status;
|
|
struct spi_controller *ctlr = spi->controller;
|
|
unsigned long flags;
|
|
|
|
status = __spi_validate(spi, message);
|
|
if (status != 0)
|
|
return status;
|
|
|
|
message->complete = spi_complete;
|
|
message->context = &done;
|
|
message->spi = spi;
|
|
|
|
SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync);
|
|
SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync);
|
|
|
|
/* If we're not using the legacy transfer method then we will
|
|
* try to transfer in the calling context so special case.
|
|
* This code would be less tricky if we could remove the
|
|
* support for driver implemented message queues.
|
|
*/
|
|
if (ctlr->transfer == spi_queued_transfer) {
|
|
spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
|
|
|
|
trace_spi_message_submit(message);
|
|
|
|
status = __spi_queued_transfer(spi, message, false);
|
|
|
|
spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
|
|
} else {
|
|
status = spi_async_locked(spi, message);
|
|
}
|
|
|
|
if (status == 0) {
|
|
/* Push out the messages in the calling context if we
|
|
* can.
|
|
*/
|
|
if (ctlr->transfer == spi_queued_transfer) {
|
|
SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics,
|
|
spi_sync_immediate);
|
|
SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics,
|
|
spi_sync_immediate);
|
|
__spi_pump_messages(ctlr, false);
|
|
}
|
|
|
|
wait_for_completion(&done);
|
|
status = message->status;
|
|
}
|
|
message->context = NULL;
|
|
return status;
|
|
}
|
|
|
|
/**
|
|
* spi_sync - blocking/synchronous SPI data transfers
|
|
* @spi: device with which data will be exchanged
|
|
* @message: describes the data transfers
|
|
* Context: can sleep
|
|
*
|
|
* This call may only be used from a context that may sleep. The sleep
|
|
* is non-interruptible, and has no timeout. Low-overhead controller
|
|
* drivers may DMA directly into and out of the message buffers.
|
|
*
|
|
* Note that the SPI device's chip select is active during the message,
|
|
* and then is normally disabled between messages. Drivers for some
|
|
* frequently-used devices may want to minimize costs of selecting a chip,
|
|
* by leaving it selected in anticipation that the next message will go
|
|
* to the same chip. (That may increase power usage.)
|
|
*
|
|
* Also, the caller is guaranteeing that the memory associated with the
|
|
* message will not be freed before this call returns.
|
|
*
|
|
* Return: zero on success, else a negative error code.
|
|
*/
|
|
int spi_sync(struct spi_device *spi, struct spi_message *message)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&spi->controller->bus_lock_mutex);
|
|
ret = __spi_sync(spi, message);
|
|
mutex_unlock(&spi->controller->bus_lock_mutex);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_sync);
|
|
|
|
/**
|
|
* spi_sync_locked - version of spi_sync with exclusive bus usage
|
|
* @spi: device with which data will be exchanged
|
|
* @message: describes the data transfers
|
|
* Context: can sleep
|
|
*
|
|
* This call may only be used from a context that may sleep. The sleep
|
|
* is non-interruptible, and has no timeout. Low-overhead controller
|
|
* drivers may DMA directly into and out of the message buffers.
|
|
*
|
|
* This call should be used by drivers that require exclusive access to the
|
|
* SPI bus. It has to be preceded by a spi_bus_lock call. The SPI bus must
|
|
* be released by a spi_bus_unlock call when the exclusive access is over.
|
|
*
|
|
* Return: zero on success, else a negative error code.
|
|
*/
|
|
int spi_sync_locked(struct spi_device *spi, struct spi_message *message)
|
|
{
|
|
return __spi_sync(spi, message);
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_sync_locked);
|
|
|
|
/**
|
|
* spi_bus_lock - obtain a lock for exclusive SPI bus usage
|
|
* @ctlr: SPI bus master that should be locked for exclusive bus access
|
|
* Context: can sleep
|
|
*
|
|
* This call may only be used from a context that may sleep. The sleep
|
|
* is non-interruptible, and has no timeout.
|
|
*
|
|
* This call should be used by drivers that require exclusive access to the
|
|
* SPI bus. The SPI bus must be released by a spi_bus_unlock call when the
|
|
* exclusive access is over. Data transfer must be done by spi_sync_locked
|
|
* and spi_async_locked calls when the SPI bus lock is held.
|
|
*
|
|
* Return: always zero.
|
|
*/
|
|
int spi_bus_lock(struct spi_controller *ctlr)
|
|
{
|
|
unsigned long flags;
|
|
|
|
mutex_lock(&ctlr->bus_lock_mutex);
|
|
|
|
spin_lock_irqsave(&ctlr->bus_lock_spinlock, flags);
|
|
ctlr->bus_lock_flag = 1;
|
|
spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags);
|
|
|
|
/* mutex remains locked until spi_bus_unlock is called */
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_bus_lock);
|
|
|
|
/**
|
|
* spi_bus_unlock - release the lock for exclusive SPI bus usage
|
|
* @ctlr: SPI bus master that was locked for exclusive bus access
|
|
* Context: can sleep
|
|
*
|
|
* This call may only be used from a context that may sleep. The sleep
|
|
* is non-interruptible, and has no timeout.
|
|
*
|
|
* This call releases an SPI bus lock previously obtained by an spi_bus_lock
|
|
* call.
|
|
*
|
|
* Return: always zero.
|
|
*/
|
|
int spi_bus_unlock(struct spi_controller *ctlr)
|
|
{
|
|
ctlr->bus_lock_flag = 0;
|
|
|
|
mutex_unlock(&ctlr->bus_lock_mutex);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_bus_unlock);
|
|
|
|
/* portable code must never pass more than 32 bytes */
|
|
#define SPI_BUFSIZ max(32, SMP_CACHE_BYTES)
|
|
|
|
static u8 *buf;
|
|
|
|
/**
|
|
* spi_write_then_read - SPI synchronous write followed by read
|
|
* @spi: device with which data will be exchanged
|
|
* @txbuf: data to be written (need not be dma-safe)
|
|
* @n_tx: size of txbuf, in bytes
|
|
* @rxbuf: buffer into which data will be read (need not be dma-safe)
|
|
* @n_rx: size of rxbuf, in bytes
|
|
* Context: can sleep
|
|
*
|
|
* This performs a half duplex MicroWire style transaction with the
|
|
* device, sending txbuf and then reading rxbuf. The return value
|
|
* is zero for success, else a negative errno status code.
|
|
* This call may only be used from a context that may sleep.
|
|
*
|
|
* Parameters to this routine are always copied using a small buffer;
|
|
* portable code should never use this for more than 32 bytes.
|
|
* Performance-sensitive or bulk transfer code should instead use
|
|
* spi_{async,sync}() calls with dma-safe buffers.
|
|
*
|
|
* Return: zero on success, else a negative error code.
|
|
*/
|
|
int spi_write_then_read(struct spi_device *spi,
|
|
const void *txbuf, unsigned n_tx,
|
|
void *rxbuf, unsigned n_rx)
|
|
{
|
|
static DEFINE_MUTEX(lock);
|
|
|
|
int status;
|
|
struct spi_message message;
|
|
struct spi_transfer x[2];
|
|
u8 *local_buf;
|
|
|
|
/* Use preallocated DMA-safe buffer if we can. We can't avoid
|
|
* copying here, (as a pure convenience thing), but we can
|
|
* keep heap costs out of the hot path unless someone else is
|
|
* using the pre-allocated buffer or the transfer is too large.
|
|
*/
|
|
if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) {
|
|
local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx),
|
|
GFP_KERNEL | GFP_DMA);
|
|
if (!local_buf)
|
|
return -ENOMEM;
|
|
} else {
|
|
local_buf = buf;
|
|
}
|
|
|
|
spi_message_init(&message);
|
|
memset(x, 0, sizeof(x));
|
|
if (n_tx) {
|
|
x[0].len = n_tx;
|
|
spi_message_add_tail(&x[0], &message);
|
|
}
|
|
if (n_rx) {
|
|
x[1].len = n_rx;
|
|
spi_message_add_tail(&x[1], &message);
|
|
}
|
|
|
|
memcpy(local_buf, txbuf, n_tx);
|
|
x[0].tx_buf = local_buf;
|
|
x[1].rx_buf = local_buf + n_tx;
|
|
|
|
/* do the i/o */
|
|
status = spi_sync(spi, &message);
|
|
if (status == 0)
|
|
memcpy(rxbuf, x[1].rx_buf, n_rx);
|
|
|
|
if (x[0].tx_buf == buf)
|
|
mutex_unlock(&lock);
|
|
else
|
|
kfree(local_buf);
|
|
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(spi_write_then_read);
|
|
|
|
/*-------------------------------------------------------------------------*/
|
|
|
|
#if IS_ENABLED(CONFIG_OF)
|
|
/* must call put_device() when done with returned spi_device device */
|
|
struct spi_device *of_find_spi_device_by_node(struct device_node *node)
|
|
{
|
|
struct device *dev = bus_find_device_by_of_node(&spi_bus_type, node);
|
|
|
|
return dev ? to_spi_device(dev) : NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_find_spi_device_by_node);
|
|
#endif /* IS_ENABLED(CONFIG_OF) */
|
|
|
|
#if IS_ENABLED(CONFIG_OF_DYNAMIC)
|
|
/* the spi controllers are not using spi_bus, so we find it with another way */
|
|
static struct spi_controller *of_find_spi_controller_by_node(struct device_node *node)
|
|
{
|
|
struct device *dev;
|
|
|
|
dev = class_find_device_by_of_node(&spi_master_class, node);
|
|
if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
|
|
dev = class_find_device_by_of_node(&spi_slave_class, node);
|
|
if (!dev)
|
|
return NULL;
|
|
|
|
/* reference got in class_find_device */
|
|
return container_of(dev, struct spi_controller, dev);
|
|
}
|
|
|
|
static int of_spi_notify(struct notifier_block *nb, unsigned long action,
|
|
void *arg)
|
|
{
|
|
struct of_reconfig_data *rd = arg;
|
|
struct spi_controller *ctlr;
|
|
struct spi_device *spi;
|
|
|
|
switch (of_reconfig_get_state_change(action, arg)) {
|
|
case OF_RECONFIG_CHANGE_ADD:
|
|
ctlr = of_find_spi_controller_by_node(rd->dn->parent);
|
|
if (ctlr == NULL)
|
|
return NOTIFY_OK; /* not for us */
|
|
|
|
if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) {
|
|
put_device(&ctlr->dev);
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
spi = of_register_spi_device(ctlr, rd->dn);
|
|
put_device(&ctlr->dev);
|
|
|
|
if (IS_ERR(spi)) {
|
|
pr_err("%s: failed to create for '%pOF'\n",
|
|
__func__, rd->dn);
|
|
of_node_clear_flag(rd->dn, OF_POPULATED);
|
|
return notifier_from_errno(PTR_ERR(spi));
|
|
}
|
|
break;
|
|
|
|
case OF_RECONFIG_CHANGE_REMOVE:
|
|
/* already depopulated? */
|
|
if (!of_node_check_flag(rd->dn, OF_POPULATED))
|
|
return NOTIFY_OK;
|
|
|
|
/* find our device by node */
|
|
spi = of_find_spi_device_by_node(rd->dn);
|
|
if (spi == NULL)
|
|
return NOTIFY_OK; /* no? not meant for us */
|
|
|
|
/* unregister takes one ref away */
|
|
spi_unregister_device(spi);
|
|
|
|
/* and put the reference of the find */
|
|
put_device(&spi->dev);
|
|
break;
|
|
}
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block spi_of_notifier = {
|
|
.notifier_call = of_spi_notify,
|
|
};
|
|
#else /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
|
|
extern struct notifier_block spi_of_notifier;
|
|
#endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */
|
|
|
|
#if IS_ENABLED(CONFIG_ACPI)
|
|
static int spi_acpi_controller_match(struct device *dev, const void *data)
|
|
{
|
|
return ACPI_COMPANION(dev->parent) == data;
|
|
}
|
|
|
|
static struct spi_controller *acpi_spi_find_controller_by_adev(struct acpi_device *adev)
|
|
{
|
|
struct device *dev;
|
|
|
|
dev = class_find_device(&spi_master_class, NULL, adev,
|
|
spi_acpi_controller_match);
|
|
if (!dev && IS_ENABLED(CONFIG_SPI_SLAVE))
|
|
dev = class_find_device(&spi_slave_class, NULL, adev,
|
|
spi_acpi_controller_match);
|
|
if (!dev)
|
|
return NULL;
|
|
|
|
return container_of(dev, struct spi_controller, dev);
|
|
}
|
|
|
|
static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev)
|
|
{
|
|
struct device *dev;
|
|
|
|
dev = bus_find_device_by_acpi_dev(&spi_bus_type, adev);
|
|
return dev ? to_spi_device(dev) : NULL;
|
|
}
|
|
|
|
static int acpi_spi_notify(struct notifier_block *nb, unsigned long value,
|
|
void *arg)
|
|
{
|
|
struct acpi_device *adev = arg;
|
|
struct spi_controller *ctlr;
|
|
struct spi_device *spi;
|
|
|
|
switch (value) {
|
|
case ACPI_RECONFIG_DEVICE_ADD:
|
|
ctlr = acpi_spi_find_controller_by_adev(adev->parent);
|
|
if (!ctlr)
|
|
break;
|
|
|
|
acpi_register_spi_device(ctlr, adev);
|
|
put_device(&ctlr->dev);
|
|
break;
|
|
case ACPI_RECONFIG_DEVICE_REMOVE:
|
|
if (!acpi_device_enumerated(adev))
|
|
break;
|
|
|
|
spi = acpi_spi_find_device_by_adev(adev);
|
|
if (!spi)
|
|
break;
|
|
|
|
spi_unregister_device(spi);
|
|
put_device(&spi->dev);
|
|
break;
|
|
}
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static struct notifier_block spi_acpi_notifier = {
|
|
.notifier_call = acpi_spi_notify,
|
|
};
|
|
#else
|
|
extern struct notifier_block spi_acpi_notifier;
|
|
#endif
|
|
|
|
static int __init spi_init(void)
|
|
{
|
|
int status;
|
|
|
|
buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL);
|
|
if (!buf) {
|
|
status = -ENOMEM;
|
|
goto err0;
|
|
}
|
|
|
|
status = bus_register(&spi_bus_type);
|
|
if (status < 0)
|
|
goto err1;
|
|
|
|
status = class_register(&spi_master_class);
|
|
if (status < 0)
|
|
goto err2;
|
|
|
|
if (IS_ENABLED(CONFIG_SPI_SLAVE)) {
|
|
status = class_register(&spi_slave_class);
|
|
if (status < 0)
|
|
goto err3;
|
|
}
|
|
|
|
if (IS_ENABLED(CONFIG_OF_DYNAMIC))
|
|
WARN_ON(of_reconfig_notifier_register(&spi_of_notifier));
|
|
if (IS_ENABLED(CONFIG_ACPI))
|
|
WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier));
|
|
|
|
return 0;
|
|
|
|
err3:
|
|
class_unregister(&spi_master_class);
|
|
err2:
|
|
bus_unregister(&spi_bus_type);
|
|
err1:
|
|
kfree(buf);
|
|
buf = NULL;
|
|
err0:
|
|
return status;
|
|
}
|
|
|
|
/* board_info is normally registered in arch_initcall(),
|
|
* but even essential drivers wait till later
|
|
*
|
|
* REVISIT only boardinfo really needs static linking. the rest (device and
|
|
* driver registration) _could_ be dynamically linked (modular) ... costs
|
|
* include needing to have boardinfo data structures be much more public.
|
|
*/
|
|
postcore_initcall(spi_init);
|