linux/drivers/spi/spi-cavium-thunderx.c

125 lines
2.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Cavium ThunderX SPI driver.
*
* Copyright (C) 2016 Cavium Inc.
* Authors: Jan Glauber <jglauber@cavium.com>
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/spi/spi.h>
#include "spi-cavium.h"
#define DRV_NAME "spi-thunderx"
#define SYS_FREQ_DEFAULT 700000000 /* 700 Mhz */
static int thunderx_spi_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
struct device *dev = &pdev->dev;
struct spi_master *master;
struct octeon_spi *p;
int ret;
master = spi_alloc_master(dev, sizeof(struct octeon_spi));
if (!master)
return -ENOMEM;
p = spi_master_get_devdata(master);
ret = pcim_enable_device(pdev);
if (ret)
goto error;
ret = pci_request_regions(pdev, DRV_NAME);
if (ret)
goto error;
p->register_base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
if (!p->register_base) {
ret = -EINVAL;
goto error;
}
p->regs.config = 0x1000;
p->regs.status = 0x1008;
p->regs.tx = 0x1010;
p->regs.data = 0x1080;
p->clk = devm_clk_get(dev, NULL);
if (IS_ERR(p->clk)) {
ret = PTR_ERR(p->clk);
goto error;
}
ret = clk_prepare_enable(p->clk);
if (ret)
goto error;
p->sys_freq = clk_get_rate(p->clk);
if (!p->sys_freq)
p->sys_freq = SYS_FREQ_DEFAULT;
dev_info(dev, "Set system clock to %u\n", p->sys_freq);
master->flags = SPI_MASTER_HALF_DUPLEX;
master->num_chipselect = 4;
master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH |
SPI_LSB_FIRST | SPI_3WIRE;
master->transfer_one_message = octeon_spi_transfer_one_message;
master->bits_per_word_mask = SPI_BPW_MASK(8);
master->max_speed_hz = OCTEON_SPI_MAX_CLOCK_HZ;
master->dev.of_node = pdev->dev.of_node;
pci_set_drvdata(pdev, master);
ret = devm_spi_register_master(dev, master);
if (ret)
goto error;
return 0;
error:
clk_disable_unprepare(p->clk);
pci_release_regions(pdev);
spi_master_put(master);
return ret;
}
static void thunderx_spi_remove(struct pci_dev *pdev)
{
struct spi_master *master = pci_get_drvdata(pdev);
struct octeon_spi *p;
p = spi_master_get_devdata(master);
if (!p)
return;
clk_disable_unprepare(p->clk);
pci_release_regions(pdev);
/* Put everything in a known state. */
writeq(0, p->register_base + OCTEON_SPI_CFG(p));
}
static const struct pci_device_id thunderx_spi_pci_id_table[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa00b) },
{ 0, }
};
MODULE_DEVICE_TABLE(pci, thunderx_spi_pci_id_table);
static struct pci_driver thunderx_spi_driver = {
.name = DRV_NAME,
.id_table = thunderx_spi_pci_id_table,
.probe = thunderx_spi_probe,
.remove = thunderx_spi_remove,
};
module_pci_driver(thunderx_spi_driver);
MODULE_DESCRIPTION("Cavium, Inc. ThunderX SPI bus driver");
MODULE_AUTHOR("Jan Glauber");
MODULE_LICENSE("GPL");