mirror of https://gitee.com/openkylin/linux.git
1263 lines
31 KiB
C
1263 lines
31 KiB
C
/* The industrial I/O core
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*
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* Copyright (c) 2008 Jonathan Cameron
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*
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* Handling of buffer allocation / resizing.
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*
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*
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* Things to look at here.
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* - Better memory allocation techniques?
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* - Alternative access techniques?
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*/
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/device.h>
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#include <linux/fs.h>
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#include <linux/cdev.h>
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#include <linux/slab.h>
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#include <linux/poll.h>
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#include <linux/sched.h>
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#include <linux/iio/iio.h>
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#include "iio_core.h"
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#include <linux/iio/sysfs.h>
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#include <linux/iio/buffer.h>
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static const char * const iio_endian_prefix[] = {
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[IIO_BE] = "be",
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[IIO_LE] = "le",
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};
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static bool iio_buffer_is_active(struct iio_buffer *buf)
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{
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return !list_empty(&buf->buffer_list);
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}
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static size_t iio_buffer_data_available(struct iio_buffer *buf)
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{
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return buf->access->data_available(buf);
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}
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static int iio_buffer_flush_hwfifo(struct iio_dev *indio_dev,
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struct iio_buffer *buf, size_t required)
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{
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if (!indio_dev->info->hwfifo_flush_to_buffer)
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return -ENODEV;
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return indio_dev->info->hwfifo_flush_to_buffer(indio_dev, required);
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}
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static bool iio_buffer_ready(struct iio_dev *indio_dev, struct iio_buffer *buf,
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size_t to_wait, int to_flush)
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{
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size_t avail;
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int flushed = 0;
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/* wakeup if the device was unregistered */
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if (!indio_dev->info)
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return true;
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/* drain the buffer if it was disabled */
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if (!iio_buffer_is_active(buf)) {
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to_wait = min_t(size_t, to_wait, 1);
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to_flush = 0;
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}
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avail = iio_buffer_data_available(buf);
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if (avail >= to_wait) {
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/* force a flush for non-blocking reads */
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if (!to_wait && !avail && to_flush)
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iio_buffer_flush_hwfifo(indio_dev, buf, to_flush);
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return true;
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}
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if (to_flush)
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flushed = iio_buffer_flush_hwfifo(indio_dev, buf,
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to_wait - avail);
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if (flushed <= 0)
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return false;
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if (avail + flushed >= to_wait)
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return true;
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return false;
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}
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/**
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* iio_buffer_read_first_n_outer() - chrdev read for buffer access
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*
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* This function relies on all buffer implementations having an
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* iio_buffer as their first element.
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**/
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ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf,
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size_t n, loff_t *f_ps)
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{
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struct iio_dev *indio_dev = filp->private_data;
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struct iio_buffer *rb = indio_dev->buffer;
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size_t datum_size;
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size_t to_wait = 0;
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size_t to_read;
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int ret;
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if (!indio_dev->info)
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return -ENODEV;
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if (!rb || !rb->access->read_first_n)
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return -EINVAL;
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datum_size = rb->bytes_per_datum;
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/*
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* If datum_size is 0 there will never be anything to read from the
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* buffer, so signal end of file now.
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*/
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if (!datum_size)
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return 0;
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to_read = min_t(size_t, n / datum_size, rb->watermark);
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if (!(filp->f_flags & O_NONBLOCK))
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to_wait = to_read;
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do {
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ret = wait_event_interruptible(rb->pollq,
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iio_buffer_ready(indio_dev, rb, to_wait, to_read));
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if (ret)
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return ret;
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if (!indio_dev->info)
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return -ENODEV;
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ret = rb->access->read_first_n(rb, n, buf);
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if (ret == 0 && (filp->f_flags & O_NONBLOCK))
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ret = -EAGAIN;
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} while (ret == 0);
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return ret;
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}
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/**
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* iio_buffer_poll() - poll the buffer to find out if it has data
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*/
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unsigned int iio_buffer_poll(struct file *filp,
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struct poll_table_struct *wait)
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{
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struct iio_dev *indio_dev = filp->private_data;
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struct iio_buffer *rb = indio_dev->buffer;
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if (!indio_dev->info)
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return -ENODEV;
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poll_wait(filp, &rb->pollq, wait);
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if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
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return POLLIN | POLLRDNORM;
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return 0;
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}
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/**
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* iio_buffer_wakeup_poll - Wakes up the buffer waitqueue
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* @indio_dev: The IIO device
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*
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* Wakes up the event waitqueue used for poll(). Should usually
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* be called when the device is unregistered.
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*/
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void iio_buffer_wakeup_poll(struct iio_dev *indio_dev)
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{
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if (!indio_dev->buffer)
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return;
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wake_up(&indio_dev->buffer->pollq);
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}
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void iio_buffer_init(struct iio_buffer *buffer)
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{
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INIT_LIST_HEAD(&buffer->demux_list);
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INIT_LIST_HEAD(&buffer->buffer_list);
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init_waitqueue_head(&buffer->pollq);
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kref_init(&buffer->ref);
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buffer->watermark = 1;
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}
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EXPORT_SYMBOL(iio_buffer_init);
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static ssize_t iio_show_scan_index(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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return sprintf(buf, "%u\n", to_iio_dev_attr(attr)->c->scan_index);
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}
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static ssize_t iio_show_fixed_type(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 iio_dev_attr *this_attr = to_iio_dev_attr(attr);
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u8 type = this_attr->c->scan_type.endianness;
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if (type == IIO_CPU) {
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#ifdef __LITTLE_ENDIAN
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type = IIO_LE;
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#else
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type = IIO_BE;
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#endif
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}
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if (this_attr->c->scan_type.repeat > 1)
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return sprintf(buf, "%s:%c%d/%dX%d>>%u\n",
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iio_endian_prefix[type],
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this_attr->c->scan_type.sign,
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this_attr->c->scan_type.realbits,
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this_attr->c->scan_type.storagebits,
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this_attr->c->scan_type.repeat,
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this_attr->c->scan_type.shift);
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else
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return sprintf(buf, "%s:%c%d/%d>>%u\n",
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iio_endian_prefix[type],
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this_attr->c->scan_type.sign,
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this_attr->c->scan_type.realbits,
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this_attr->c->scan_type.storagebits,
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this_attr->c->scan_type.shift);
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}
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static ssize_t iio_scan_el_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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int ret;
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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/* Ensure ret is 0 or 1. */
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ret = !!test_bit(to_iio_dev_attr(attr)->address,
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indio_dev->buffer->scan_mask);
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return sprintf(buf, "%d\n", ret);
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}
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/* Note NULL used as error indicator as it doesn't make sense. */
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static const unsigned long *iio_scan_mask_match(const unsigned long *av_masks,
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unsigned int masklength,
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const unsigned long *mask)
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{
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if (bitmap_empty(mask, masklength))
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return NULL;
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while (*av_masks) {
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if (bitmap_subset(mask, av_masks, masklength))
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return av_masks;
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av_masks += BITS_TO_LONGS(masklength);
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}
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return NULL;
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}
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static bool iio_validate_scan_mask(struct iio_dev *indio_dev,
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const unsigned long *mask)
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{
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if (!indio_dev->setup_ops->validate_scan_mask)
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return true;
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return indio_dev->setup_ops->validate_scan_mask(indio_dev, mask);
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}
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/**
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* iio_scan_mask_set() - set particular bit in the scan mask
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* @indio_dev: the iio device
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* @buffer: the buffer whose scan mask we are interested in
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* @bit: the bit to be set.
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*
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* Note that at this point we have no way of knowing what other
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* buffers might request, hence this code only verifies that the
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* individual buffers request is plausible.
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*/
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static int iio_scan_mask_set(struct iio_dev *indio_dev,
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struct iio_buffer *buffer, int bit)
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{
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const unsigned long *mask;
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unsigned long *trialmask;
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trialmask = kmalloc(sizeof(*trialmask)*
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BITS_TO_LONGS(indio_dev->masklength),
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GFP_KERNEL);
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if (trialmask == NULL)
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return -ENOMEM;
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if (!indio_dev->masklength) {
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WARN_ON("Trying to set scanmask prior to registering buffer\n");
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goto err_invalid_mask;
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}
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bitmap_copy(trialmask, buffer->scan_mask, indio_dev->masklength);
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set_bit(bit, trialmask);
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if (!iio_validate_scan_mask(indio_dev, trialmask))
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goto err_invalid_mask;
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if (indio_dev->available_scan_masks) {
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mask = iio_scan_mask_match(indio_dev->available_scan_masks,
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indio_dev->masklength,
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trialmask);
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if (!mask)
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goto err_invalid_mask;
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}
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bitmap_copy(buffer->scan_mask, trialmask, indio_dev->masklength);
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kfree(trialmask);
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return 0;
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err_invalid_mask:
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kfree(trialmask);
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return -EINVAL;
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}
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static int iio_scan_mask_clear(struct iio_buffer *buffer, int bit)
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{
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clear_bit(bit, buffer->scan_mask);
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return 0;
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}
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static ssize_t iio_scan_el_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t len)
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{
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int ret;
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bool state;
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct iio_buffer *buffer = indio_dev->buffer;
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struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
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ret = strtobool(buf, &state);
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if (ret < 0)
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return ret;
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mutex_lock(&indio_dev->mlock);
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if (iio_buffer_is_active(indio_dev->buffer)) {
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ret = -EBUSY;
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goto error_ret;
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}
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ret = iio_scan_mask_query(indio_dev, buffer, this_attr->address);
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if (ret < 0)
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goto error_ret;
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if (!state && ret) {
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ret = iio_scan_mask_clear(buffer, this_attr->address);
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if (ret)
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goto error_ret;
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} else if (state && !ret) {
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ret = iio_scan_mask_set(indio_dev, buffer, this_attr->address);
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if (ret)
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goto error_ret;
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}
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error_ret:
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mutex_unlock(&indio_dev->mlock);
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return ret < 0 ? ret : len;
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}
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static ssize_t iio_scan_el_ts_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 iio_dev *indio_dev = dev_to_iio_dev(dev);
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return sprintf(buf, "%d\n", indio_dev->buffer->scan_timestamp);
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}
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static ssize_t iio_scan_el_ts_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf,
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size_t len)
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{
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int ret;
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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bool state;
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ret = strtobool(buf, &state);
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if (ret < 0)
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return ret;
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mutex_lock(&indio_dev->mlock);
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if (iio_buffer_is_active(indio_dev->buffer)) {
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ret = -EBUSY;
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goto error_ret;
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}
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indio_dev->buffer->scan_timestamp = state;
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error_ret:
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mutex_unlock(&indio_dev->mlock);
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return ret ? ret : len;
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}
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static int iio_buffer_add_channel_sysfs(struct iio_dev *indio_dev,
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const struct iio_chan_spec *chan)
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{
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int ret, attrcount = 0;
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struct iio_buffer *buffer = indio_dev->buffer;
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ret = __iio_add_chan_devattr("index",
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chan,
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&iio_show_scan_index,
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NULL,
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0,
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IIO_SEPARATE,
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&indio_dev->dev,
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&buffer->scan_el_dev_attr_list);
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if (ret)
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return ret;
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attrcount++;
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ret = __iio_add_chan_devattr("type",
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chan,
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&iio_show_fixed_type,
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NULL,
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0,
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0,
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&indio_dev->dev,
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&buffer->scan_el_dev_attr_list);
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if (ret)
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return ret;
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attrcount++;
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if (chan->type != IIO_TIMESTAMP)
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ret = __iio_add_chan_devattr("en",
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chan,
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&iio_scan_el_show,
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&iio_scan_el_store,
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chan->scan_index,
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0,
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&indio_dev->dev,
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&buffer->scan_el_dev_attr_list);
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else
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ret = __iio_add_chan_devattr("en",
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chan,
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&iio_scan_el_ts_show,
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&iio_scan_el_ts_store,
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chan->scan_index,
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0,
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&indio_dev->dev,
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&buffer->scan_el_dev_attr_list);
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if (ret)
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return ret;
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attrcount++;
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ret = attrcount;
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return ret;
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}
|
|
|
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static ssize_t iio_buffer_read_length(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 iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct iio_buffer *buffer = indio_dev->buffer;
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return sprintf(buf, "%d\n", buffer->length);
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}
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|
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static ssize_t iio_buffer_write_length(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t len)
|
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{
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struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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struct iio_buffer *buffer = indio_dev->buffer;
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unsigned int val;
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int ret;
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|
|
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ret = kstrtouint(buf, 10, &val);
|
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if (ret)
|
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return ret;
|
|
|
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if (val == buffer->length)
|
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return len;
|
|
|
|
mutex_lock(&indio_dev->mlock);
|
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if (iio_buffer_is_active(indio_dev->buffer)) {
|
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ret = -EBUSY;
|
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} else {
|
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buffer->access->set_length(buffer, val);
|
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ret = 0;
|
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}
|
|
if (ret)
|
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goto out;
|
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if (buffer->length && buffer->length < buffer->watermark)
|
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buffer->watermark = buffer->length;
|
|
out:
|
|
mutex_unlock(&indio_dev->mlock);
|
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|
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return ret ? ret : len;
|
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}
|
|
|
|
static ssize_t iio_buffer_show_enable(struct device *dev,
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struct device_attribute *attr,
|
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char *buf)
|
|
{
|
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
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return sprintf(buf, "%d\n", iio_buffer_is_active(indio_dev->buffer));
|
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}
|
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|
|
static int iio_compute_scan_bytes(struct iio_dev *indio_dev,
|
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const unsigned long *mask, bool timestamp)
|
|
{
|
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const struct iio_chan_spec *ch;
|
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unsigned bytes = 0;
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int length, i;
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|
|
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/* How much space will the demuxed element take? */
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for_each_set_bit(i, mask,
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indio_dev->masklength) {
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ch = iio_find_channel_from_si(indio_dev, i);
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if (ch->scan_type.repeat > 1)
|
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length = ch->scan_type.storagebits / 8 *
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ch->scan_type.repeat;
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else
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length = ch->scan_type.storagebits / 8;
|
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bytes = ALIGN(bytes, length);
|
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bytes += length;
|
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}
|
|
if (timestamp) {
|
|
ch = iio_find_channel_from_si(indio_dev,
|
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indio_dev->scan_index_timestamp);
|
|
if (ch->scan_type.repeat > 1)
|
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length = ch->scan_type.storagebits / 8 *
|
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ch->scan_type.repeat;
|
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else
|
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length = ch->scan_type.storagebits / 8;
|
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bytes = ALIGN(bytes, length);
|
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bytes += length;
|
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}
|
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return bytes;
|
|
}
|
|
|
|
static void iio_buffer_activate(struct iio_dev *indio_dev,
|
|
struct iio_buffer *buffer)
|
|
{
|
|
iio_buffer_get(buffer);
|
|
list_add(&buffer->buffer_list, &indio_dev->buffer_list);
|
|
}
|
|
|
|
static void iio_buffer_deactivate(struct iio_buffer *buffer)
|
|
{
|
|
list_del_init(&buffer->buffer_list);
|
|
wake_up_interruptible(&buffer->pollq);
|
|
iio_buffer_put(buffer);
|
|
}
|
|
|
|
void iio_disable_all_buffers(struct iio_dev *indio_dev)
|
|
{
|
|
struct iio_buffer *buffer, *_buffer;
|
|
|
|
if (list_empty(&indio_dev->buffer_list))
|
|
return;
|
|
|
|
if (indio_dev->setup_ops->predisable)
|
|
indio_dev->setup_ops->predisable(indio_dev);
|
|
|
|
list_for_each_entry_safe(buffer, _buffer,
|
|
&indio_dev->buffer_list, buffer_list)
|
|
iio_buffer_deactivate(buffer);
|
|
|
|
indio_dev->currentmode = INDIO_DIRECT_MODE;
|
|
if (indio_dev->setup_ops->postdisable)
|
|
indio_dev->setup_ops->postdisable(indio_dev);
|
|
|
|
if (indio_dev->available_scan_masks == NULL)
|
|
kfree(indio_dev->active_scan_mask);
|
|
}
|
|
|
|
static void iio_buffer_update_bytes_per_datum(struct iio_dev *indio_dev,
|
|
struct iio_buffer *buffer)
|
|
{
|
|
unsigned int bytes;
|
|
|
|
if (!buffer->access->set_bytes_per_datum)
|
|
return;
|
|
|
|
bytes = iio_compute_scan_bytes(indio_dev, buffer->scan_mask,
|
|
buffer->scan_timestamp);
|
|
|
|
buffer->access->set_bytes_per_datum(buffer, bytes);
|
|
}
|
|
|
|
static int __iio_update_buffers(struct iio_dev *indio_dev,
|
|
struct iio_buffer *insert_buffer,
|
|
struct iio_buffer *remove_buffer)
|
|
{
|
|
int ret;
|
|
int success = 0;
|
|
struct iio_buffer *buffer;
|
|
unsigned long *compound_mask;
|
|
const unsigned long *old_mask;
|
|
|
|
/* Wind down existing buffers - iff there are any */
|
|
if (!list_empty(&indio_dev->buffer_list)) {
|
|
if (indio_dev->setup_ops->predisable) {
|
|
ret = indio_dev->setup_ops->predisable(indio_dev);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
indio_dev->currentmode = INDIO_DIRECT_MODE;
|
|
if (indio_dev->setup_ops->postdisable) {
|
|
ret = indio_dev->setup_ops->postdisable(indio_dev);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
}
|
|
/* Keep a copy of current setup to allow roll back */
|
|
old_mask = indio_dev->active_scan_mask;
|
|
if (!indio_dev->available_scan_masks)
|
|
indio_dev->active_scan_mask = NULL;
|
|
|
|
if (remove_buffer)
|
|
iio_buffer_deactivate(remove_buffer);
|
|
if (insert_buffer)
|
|
iio_buffer_activate(indio_dev, insert_buffer);
|
|
|
|
/* If no buffers in list, we are done */
|
|
if (list_empty(&indio_dev->buffer_list)) {
|
|
indio_dev->currentmode = INDIO_DIRECT_MODE;
|
|
if (indio_dev->available_scan_masks == NULL)
|
|
kfree(old_mask);
|
|
return 0;
|
|
}
|
|
|
|
/* What scan mask do we actually have? */
|
|
compound_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
|
|
sizeof(long), GFP_KERNEL);
|
|
if (compound_mask == NULL) {
|
|
if (indio_dev->available_scan_masks == NULL)
|
|
kfree(old_mask);
|
|
return -ENOMEM;
|
|
}
|
|
indio_dev->scan_timestamp = 0;
|
|
|
|
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
|
|
bitmap_or(compound_mask, compound_mask, buffer->scan_mask,
|
|
indio_dev->masklength);
|
|
indio_dev->scan_timestamp |= buffer->scan_timestamp;
|
|
}
|
|
if (indio_dev->available_scan_masks) {
|
|
indio_dev->active_scan_mask =
|
|
iio_scan_mask_match(indio_dev->available_scan_masks,
|
|
indio_dev->masklength,
|
|
compound_mask);
|
|
if (indio_dev->active_scan_mask == NULL) {
|
|
/*
|
|
* Roll back.
|
|
* Note can only occur when adding a buffer.
|
|
*/
|
|
iio_buffer_deactivate(insert_buffer);
|
|
if (old_mask) {
|
|
indio_dev->active_scan_mask = old_mask;
|
|
success = -EINVAL;
|
|
}
|
|
else {
|
|
kfree(compound_mask);
|
|
ret = -EINVAL;
|
|
return ret;
|
|
}
|
|
}
|
|
} else {
|
|
indio_dev->active_scan_mask = compound_mask;
|
|
}
|
|
|
|
iio_update_demux(indio_dev);
|
|
|
|
/* Wind up again */
|
|
if (indio_dev->setup_ops->preenable) {
|
|
ret = indio_dev->setup_ops->preenable(indio_dev);
|
|
if (ret) {
|
|
printk(KERN_ERR
|
|
"Buffer not started: buffer preenable failed (%d)\n", ret);
|
|
goto error_remove_inserted;
|
|
}
|
|
}
|
|
indio_dev->scan_bytes =
|
|
iio_compute_scan_bytes(indio_dev,
|
|
indio_dev->active_scan_mask,
|
|
indio_dev->scan_timestamp);
|
|
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
|
|
iio_buffer_update_bytes_per_datum(indio_dev, buffer);
|
|
if (buffer->access->request_update) {
|
|
ret = buffer->access->request_update(buffer);
|
|
if (ret) {
|
|
printk(KERN_INFO
|
|
"Buffer not started: buffer parameter update failed (%d)\n", ret);
|
|
goto error_run_postdisable;
|
|
}
|
|
}
|
|
}
|
|
if (indio_dev->info->update_scan_mode) {
|
|
ret = indio_dev->info
|
|
->update_scan_mode(indio_dev,
|
|
indio_dev->active_scan_mask);
|
|
if (ret < 0) {
|
|
printk(KERN_INFO "Buffer not started: update scan mode failed (%d)\n", ret);
|
|
goto error_run_postdisable;
|
|
}
|
|
}
|
|
/* Definitely possible for devices to support both of these. */
|
|
if ((indio_dev->modes & INDIO_BUFFER_TRIGGERED) && indio_dev->trig) {
|
|
indio_dev->currentmode = INDIO_BUFFER_TRIGGERED;
|
|
} else if (indio_dev->modes & INDIO_BUFFER_HARDWARE) {
|
|
indio_dev->currentmode = INDIO_BUFFER_HARDWARE;
|
|
} else if (indio_dev->modes & INDIO_BUFFER_SOFTWARE) {
|
|
indio_dev->currentmode = INDIO_BUFFER_SOFTWARE;
|
|
} else { /* Should never be reached */
|
|
/* Can only occur on first buffer */
|
|
if (indio_dev->modes & INDIO_BUFFER_TRIGGERED)
|
|
pr_info("Buffer not started: no trigger\n");
|
|
ret = -EINVAL;
|
|
goto error_run_postdisable;
|
|
}
|
|
|
|
if (indio_dev->setup_ops->postenable) {
|
|
ret = indio_dev->setup_ops->postenable(indio_dev);
|
|
if (ret) {
|
|
printk(KERN_INFO
|
|
"Buffer not started: postenable failed (%d)\n", ret);
|
|
indio_dev->currentmode = INDIO_DIRECT_MODE;
|
|
if (indio_dev->setup_ops->postdisable)
|
|
indio_dev->setup_ops->postdisable(indio_dev);
|
|
goto error_disable_all_buffers;
|
|
}
|
|
}
|
|
|
|
if (indio_dev->available_scan_masks)
|
|
kfree(compound_mask);
|
|
else
|
|
kfree(old_mask);
|
|
|
|
return success;
|
|
|
|
error_disable_all_buffers:
|
|
indio_dev->currentmode = INDIO_DIRECT_MODE;
|
|
error_run_postdisable:
|
|
if (indio_dev->setup_ops->postdisable)
|
|
indio_dev->setup_ops->postdisable(indio_dev);
|
|
error_remove_inserted:
|
|
if (insert_buffer)
|
|
iio_buffer_deactivate(insert_buffer);
|
|
indio_dev->active_scan_mask = old_mask;
|
|
kfree(compound_mask);
|
|
return ret;
|
|
}
|
|
|
|
int iio_update_buffers(struct iio_dev *indio_dev,
|
|
struct iio_buffer *insert_buffer,
|
|
struct iio_buffer *remove_buffer)
|
|
{
|
|
int ret;
|
|
|
|
if (insert_buffer == remove_buffer)
|
|
return 0;
|
|
|
|
mutex_lock(&indio_dev->info_exist_lock);
|
|
mutex_lock(&indio_dev->mlock);
|
|
|
|
if (insert_buffer && iio_buffer_is_active(insert_buffer))
|
|
insert_buffer = NULL;
|
|
|
|
if (remove_buffer && !iio_buffer_is_active(remove_buffer))
|
|
remove_buffer = NULL;
|
|
|
|
if (!insert_buffer && !remove_buffer) {
|
|
ret = 0;
|
|
goto out_unlock;
|
|
}
|
|
|
|
if (indio_dev->info == NULL) {
|
|
ret = -ENODEV;
|
|
goto out_unlock;
|
|
}
|
|
|
|
ret = __iio_update_buffers(indio_dev, insert_buffer, remove_buffer);
|
|
|
|
out_unlock:
|
|
mutex_unlock(&indio_dev->mlock);
|
|
mutex_unlock(&indio_dev->info_exist_lock);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_update_buffers);
|
|
|
|
static ssize_t iio_buffer_store_enable(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf,
|
|
size_t len)
|
|
{
|
|
int ret;
|
|
bool requested_state;
|
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
|
bool inlist;
|
|
|
|
ret = strtobool(buf, &requested_state);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
mutex_lock(&indio_dev->mlock);
|
|
|
|
/* Find out if it is in the list */
|
|
inlist = iio_buffer_is_active(indio_dev->buffer);
|
|
/* Already in desired state */
|
|
if (inlist == requested_state)
|
|
goto done;
|
|
|
|
if (requested_state)
|
|
ret = __iio_update_buffers(indio_dev,
|
|
indio_dev->buffer, NULL);
|
|
else
|
|
ret = __iio_update_buffers(indio_dev,
|
|
NULL, indio_dev->buffer);
|
|
|
|
if (ret < 0)
|
|
goto done;
|
|
done:
|
|
mutex_unlock(&indio_dev->mlock);
|
|
return (ret < 0) ? ret : len;
|
|
}
|
|
|
|
static const char * const iio_scan_elements_group_name = "scan_elements";
|
|
|
|
static ssize_t iio_buffer_show_watermark(struct device *dev,
|
|
struct device_attribute *attr,
|
|
char *buf)
|
|
{
|
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
|
struct iio_buffer *buffer = indio_dev->buffer;
|
|
|
|
return sprintf(buf, "%u\n", buffer->watermark);
|
|
}
|
|
|
|
static ssize_t iio_buffer_store_watermark(struct device *dev,
|
|
struct device_attribute *attr,
|
|
const char *buf,
|
|
size_t len)
|
|
{
|
|
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
|
|
struct iio_buffer *buffer = indio_dev->buffer;
|
|
unsigned int val;
|
|
int ret;
|
|
|
|
ret = kstrtouint(buf, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
if (!val)
|
|
return -EINVAL;
|
|
|
|
mutex_lock(&indio_dev->mlock);
|
|
|
|
if (val > buffer->length) {
|
|
ret = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (iio_buffer_is_active(indio_dev->buffer)) {
|
|
ret = -EBUSY;
|
|
goto out;
|
|
}
|
|
|
|
buffer->watermark = val;
|
|
|
|
if (indio_dev->info->hwfifo_set_watermark)
|
|
indio_dev->info->hwfifo_set_watermark(indio_dev, val);
|
|
out:
|
|
mutex_unlock(&indio_dev->mlock);
|
|
|
|
return ret ? ret : len;
|
|
}
|
|
|
|
static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length,
|
|
iio_buffer_write_length);
|
|
static struct device_attribute dev_attr_length_ro = __ATTR(length,
|
|
S_IRUGO, iio_buffer_read_length, NULL);
|
|
static DEVICE_ATTR(enable, S_IRUGO | S_IWUSR,
|
|
iio_buffer_show_enable, iio_buffer_store_enable);
|
|
static DEVICE_ATTR(watermark, S_IRUGO | S_IWUSR,
|
|
iio_buffer_show_watermark, iio_buffer_store_watermark);
|
|
|
|
static struct attribute *iio_buffer_attrs[] = {
|
|
&dev_attr_length.attr,
|
|
&dev_attr_enable.attr,
|
|
&dev_attr_watermark.attr,
|
|
};
|
|
|
|
int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
|
|
{
|
|
struct iio_dev_attr *p;
|
|
struct attribute **attr;
|
|
struct iio_buffer *buffer = indio_dev->buffer;
|
|
int ret, i, attrn, attrcount, attrcount_orig = 0;
|
|
const struct iio_chan_spec *channels;
|
|
|
|
if (!buffer)
|
|
return 0;
|
|
|
|
attrcount = 0;
|
|
if (buffer->attrs) {
|
|
while (buffer->attrs[attrcount] != NULL)
|
|
attrcount++;
|
|
}
|
|
|
|
attr = kcalloc(attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1,
|
|
sizeof(struct attribute *), GFP_KERNEL);
|
|
if (!attr)
|
|
return -ENOMEM;
|
|
|
|
memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs));
|
|
if (!buffer->access->set_length)
|
|
attr[0] = &dev_attr_length_ro.attr;
|
|
|
|
if (buffer->attrs)
|
|
memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs,
|
|
sizeof(struct attribute *) * attrcount);
|
|
|
|
attr[attrcount + ARRAY_SIZE(iio_buffer_attrs)] = NULL;
|
|
|
|
buffer->buffer_group.name = "buffer";
|
|
buffer->buffer_group.attrs = attr;
|
|
|
|
indio_dev->groups[indio_dev->groupcounter++] = &buffer->buffer_group;
|
|
|
|
if (buffer->scan_el_attrs != NULL) {
|
|
attr = buffer->scan_el_attrs->attrs;
|
|
while (*attr++ != NULL)
|
|
attrcount_orig++;
|
|
}
|
|
attrcount = attrcount_orig;
|
|
INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list);
|
|
channels = indio_dev->channels;
|
|
if (channels) {
|
|
/* new magic */
|
|
for (i = 0; i < indio_dev->num_channels; i++) {
|
|
if (channels[i].scan_index < 0)
|
|
continue;
|
|
|
|
/* Establish necessary mask length */
|
|
if (channels[i].scan_index >
|
|
(int)indio_dev->masklength - 1)
|
|
indio_dev->masklength
|
|
= channels[i].scan_index + 1;
|
|
|
|
ret = iio_buffer_add_channel_sysfs(indio_dev,
|
|
&channels[i]);
|
|
if (ret < 0)
|
|
goto error_cleanup_dynamic;
|
|
attrcount += ret;
|
|
if (channels[i].type == IIO_TIMESTAMP)
|
|
indio_dev->scan_index_timestamp =
|
|
channels[i].scan_index;
|
|
}
|
|
if (indio_dev->masklength && buffer->scan_mask == NULL) {
|
|
buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
|
|
sizeof(*buffer->scan_mask),
|
|
GFP_KERNEL);
|
|
if (buffer->scan_mask == NULL) {
|
|
ret = -ENOMEM;
|
|
goto error_cleanup_dynamic;
|
|
}
|
|
}
|
|
}
|
|
|
|
buffer->scan_el_group.name = iio_scan_elements_group_name;
|
|
|
|
buffer->scan_el_group.attrs = kcalloc(attrcount + 1,
|
|
sizeof(buffer->scan_el_group.attrs[0]),
|
|
GFP_KERNEL);
|
|
if (buffer->scan_el_group.attrs == NULL) {
|
|
ret = -ENOMEM;
|
|
goto error_free_scan_mask;
|
|
}
|
|
if (buffer->scan_el_attrs)
|
|
memcpy(buffer->scan_el_group.attrs, buffer->scan_el_attrs,
|
|
sizeof(buffer->scan_el_group.attrs[0])*attrcount_orig);
|
|
attrn = attrcount_orig;
|
|
|
|
list_for_each_entry(p, &buffer->scan_el_dev_attr_list, l)
|
|
buffer->scan_el_group.attrs[attrn++] = &p->dev_attr.attr;
|
|
indio_dev->groups[indio_dev->groupcounter++] = &buffer->scan_el_group;
|
|
|
|
return 0;
|
|
|
|
error_free_scan_mask:
|
|
kfree(buffer->scan_mask);
|
|
error_cleanup_dynamic:
|
|
iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list);
|
|
kfree(indio_dev->buffer->buffer_group.attrs);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev)
|
|
{
|
|
if (!indio_dev->buffer)
|
|
return;
|
|
|
|
kfree(indio_dev->buffer->scan_mask);
|
|
kfree(indio_dev->buffer->buffer_group.attrs);
|
|
kfree(indio_dev->buffer->scan_el_group.attrs);
|
|
iio_free_chan_devattr_list(&indio_dev->buffer->scan_el_dev_attr_list);
|
|
}
|
|
|
|
/**
|
|
* iio_validate_scan_mask_onehot() - Validates that exactly one channel is selected
|
|
* @indio_dev: the iio device
|
|
* @mask: scan mask to be checked
|
|
*
|
|
* Return true if exactly one bit is set in the scan mask, false otherwise. It
|
|
* can be used for devices where only one channel can be active for sampling at
|
|
* a time.
|
|
*/
|
|
bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev,
|
|
const unsigned long *mask)
|
|
{
|
|
return bitmap_weight(mask, indio_dev->masklength) == 1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_validate_scan_mask_onehot);
|
|
|
|
int iio_scan_mask_query(struct iio_dev *indio_dev,
|
|
struct iio_buffer *buffer, int bit)
|
|
{
|
|
if (bit > indio_dev->masklength)
|
|
return -EINVAL;
|
|
|
|
if (!buffer->scan_mask)
|
|
return 0;
|
|
|
|
/* Ensure return value is 0 or 1. */
|
|
return !!test_bit(bit, buffer->scan_mask);
|
|
};
|
|
EXPORT_SYMBOL_GPL(iio_scan_mask_query);
|
|
|
|
/**
|
|
* struct iio_demux_table() - table describing demux memcpy ops
|
|
* @from: index to copy from
|
|
* @to: index to copy to
|
|
* @length: how many bytes to copy
|
|
* @l: list head used for management
|
|
*/
|
|
struct iio_demux_table {
|
|
unsigned from;
|
|
unsigned to;
|
|
unsigned length;
|
|
struct list_head l;
|
|
};
|
|
|
|
static const void *iio_demux(struct iio_buffer *buffer,
|
|
const void *datain)
|
|
{
|
|
struct iio_demux_table *t;
|
|
|
|
if (list_empty(&buffer->demux_list))
|
|
return datain;
|
|
list_for_each_entry(t, &buffer->demux_list, l)
|
|
memcpy(buffer->demux_bounce + t->to,
|
|
datain + t->from, t->length);
|
|
|
|
return buffer->demux_bounce;
|
|
}
|
|
|
|
static int iio_push_to_buffer(struct iio_buffer *buffer, const void *data)
|
|
{
|
|
const void *dataout = iio_demux(buffer, data);
|
|
int ret;
|
|
|
|
ret = buffer->access->store_to(buffer, dataout);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* We can't just test for watermark to decide if we wake the poll queue
|
|
* because read may request less samples than the watermark.
|
|
*/
|
|
wake_up_interruptible_poll(&buffer->pollq, POLLIN | POLLRDNORM);
|
|
return 0;
|
|
}
|
|
|
|
static void iio_buffer_demux_free(struct iio_buffer *buffer)
|
|
{
|
|
struct iio_demux_table *p, *q;
|
|
list_for_each_entry_safe(p, q, &buffer->demux_list, l) {
|
|
list_del(&p->l);
|
|
kfree(p);
|
|
}
|
|
}
|
|
|
|
|
|
int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
|
|
{
|
|
int ret;
|
|
struct iio_buffer *buf;
|
|
|
|
list_for_each_entry(buf, &indio_dev->buffer_list, buffer_list) {
|
|
ret = iio_push_to_buffer(buf, data);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_push_to_buffers);
|
|
|
|
static int iio_buffer_add_demux(struct iio_buffer *buffer,
|
|
struct iio_demux_table **p, unsigned int in_loc, unsigned int out_loc,
|
|
unsigned int length)
|
|
{
|
|
|
|
if (*p && (*p)->from + (*p)->length == in_loc &&
|
|
(*p)->to + (*p)->length == out_loc) {
|
|
(*p)->length += length;
|
|
} else {
|
|
*p = kmalloc(sizeof(**p), GFP_KERNEL);
|
|
if (*p == NULL)
|
|
return -ENOMEM;
|
|
(*p)->from = in_loc;
|
|
(*p)->to = out_loc;
|
|
(*p)->length = length;
|
|
list_add_tail(&(*p)->l, &buffer->demux_list);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int iio_buffer_update_demux(struct iio_dev *indio_dev,
|
|
struct iio_buffer *buffer)
|
|
{
|
|
const struct iio_chan_spec *ch;
|
|
int ret, in_ind = -1, out_ind, length;
|
|
unsigned in_loc = 0, out_loc = 0;
|
|
struct iio_demux_table *p = NULL;
|
|
|
|
/* Clear out any old demux */
|
|
iio_buffer_demux_free(buffer);
|
|
kfree(buffer->demux_bounce);
|
|
buffer->demux_bounce = NULL;
|
|
|
|
/* First work out which scan mode we will actually have */
|
|
if (bitmap_equal(indio_dev->active_scan_mask,
|
|
buffer->scan_mask,
|
|
indio_dev->masklength))
|
|
return 0;
|
|
|
|
/* Now we have the two masks, work from least sig and build up sizes */
|
|
for_each_set_bit(out_ind,
|
|
buffer->scan_mask,
|
|
indio_dev->masklength) {
|
|
in_ind = find_next_bit(indio_dev->active_scan_mask,
|
|
indio_dev->masklength,
|
|
in_ind + 1);
|
|
while (in_ind != out_ind) {
|
|
in_ind = find_next_bit(indio_dev->active_scan_mask,
|
|
indio_dev->masklength,
|
|
in_ind + 1);
|
|
ch = iio_find_channel_from_si(indio_dev, in_ind);
|
|
if (ch->scan_type.repeat > 1)
|
|
length = ch->scan_type.storagebits / 8 *
|
|
ch->scan_type.repeat;
|
|
else
|
|
length = ch->scan_type.storagebits / 8;
|
|
/* Make sure we are aligned */
|
|
in_loc = roundup(in_loc, length) + length;
|
|
}
|
|
ch = iio_find_channel_from_si(indio_dev, in_ind);
|
|
if (ch->scan_type.repeat > 1)
|
|
length = ch->scan_type.storagebits / 8 *
|
|
ch->scan_type.repeat;
|
|
else
|
|
length = ch->scan_type.storagebits / 8;
|
|
out_loc = roundup(out_loc, length);
|
|
in_loc = roundup(in_loc, length);
|
|
ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
|
|
if (ret)
|
|
goto error_clear_mux_table;
|
|
out_loc += length;
|
|
in_loc += length;
|
|
}
|
|
/* Relies on scan_timestamp being last */
|
|
if (buffer->scan_timestamp) {
|
|
ch = iio_find_channel_from_si(indio_dev,
|
|
indio_dev->scan_index_timestamp);
|
|
if (ch->scan_type.repeat > 1)
|
|
length = ch->scan_type.storagebits / 8 *
|
|
ch->scan_type.repeat;
|
|
else
|
|
length = ch->scan_type.storagebits / 8;
|
|
out_loc = roundup(out_loc, length);
|
|
in_loc = roundup(in_loc, length);
|
|
ret = iio_buffer_add_demux(buffer, &p, in_loc, out_loc, length);
|
|
if (ret)
|
|
goto error_clear_mux_table;
|
|
out_loc += length;
|
|
in_loc += length;
|
|
}
|
|
buffer->demux_bounce = kzalloc(out_loc, GFP_KERNEL);
|
|
if (buffer->demux_bounce == NULL) {
|
|
ret = -ENOMEM;
|
|
goto error_clear_mux_table;
|
|
}
|
|
return 0;
|
|
|
|
error_clear_mux_table:
|
|
iio_buffer_demux_free(buffer);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int iio_update_demux(struct iio_dev *indio_dev)
|
|
{
|
|
struct iio_buffer *buffer;
|
|
int ret;
|
|
|
|
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list) {
|
|
ret = iio_buffer_update_demux(indio_dev, buffer);
|
|
if (ret < 0)
|
|
goto error_clear_mux_table;
|
|
}
|
|
return 0;
|
|
|
|
error_clear_mux_table:
|
|
list_for_each_entry(buffer, &indio_dev->buffer_list, buffer_list)
|
|
iio_buffer_demux_free(buffer);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_update_demux);
|
|
|
|
/**
|
|
* iio_buffer_release() - Free a buffer's resources
|
|
* @ref: Pointer to the kref embedded in the iio_buffer struct
|
|
*
|
|
* This function is called when the last reference to the buffer has been
|
|
* dropped. It will typically free all resources allocated by the buffer. Do not
|
|
* call this function manually, always use iio_buffer_put() when done using a
|
|
* buffer.
|
|
*/
|
|
static void iio_buffer_release(struct kref *ref)
|
|
{
|
|
struct iio_buffer *buffer = container_of(ref, struct iio_buffer, ref);
|
|
|
|
buffer->access->release(buffer);
|
|
}
|
|
|
|
/**
|
|
* iio_buffer_get() - Grab a reference to the buffer
|
|
* @buffer: The buffer to grab a reference for, may be NULL
|
|
*
|
|
* Returns the pointer to the buffer that was passed into the function.
|
|
*/
|
|
struct iio_buffer *iio_buffer_get(struct iio_buffer *buffer)
|
|
{
|
|
if (buffer)
|
|
kref_get(&buffer->ref);
|
|
|
|
return buffer;
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_buffer_get);
|
|
|
|
/**
|
|
* iio_buffer_put() - Release the reference to the buffer
|
|
* @buffer: The buffer to release the reference for, may be NULL
|
|
*/
|
|
void iio_buffer_put(struct iio_buffer *buffer)
|
|
{
|
|
if (buffer)
|
|
kref_put(&buffer->ref, iio_buffer_release);
|
|
}
|
|
EXPORT_SYMBOL_GPL(iio_buffer_put);
|