linux-zen-server/drivers/mfd/stmpe-spi.c

160 lines
3.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* ST Microelectronics MFD: stmpe's spi client specific driver
*
* Copyright (C) ST Microelectronics SA 2011
*
* Author: Viresh Kumar <vireshk@kernel.org> for ST Microelectronics
*/
#include <linux/spi/spi.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/types.h>
#include "stmpe.h"
#define READ_CMD (1 << 7)
static int spi_reg_read(struct stmpe *stmpe, u8 reg)
{
struct spi_device *spi = stmpe->client;
int status = spi_w8r16(spi, reg | READ_CMD);
return (status < 0) ? status : status >> 8;
}
static int spi_reg_write(struct stmpe *stmpe, u8 reg, u8 val)
{
struct spi_device *spi = stmpe->client;
u16 cmd = (val << 8) | reg;
return spi_write(spi, (const u8 *)&cmd, 2);
}
static int spi_block_read(struct stmpe *stmpe, u8 reg, u8 length, u8 *values)
{
int ret, i;
for (i = 0; i < length; i++) {
ret = spi_reg_read(stmpe, reg + i);
if (ret < 0)
return ret;
*(values + i) = ret;
}
return 0;
}
static int spi_block_write(struct stmpe *stmpe, u8 reg, u8 length,
const u8 *values)
{
int ret = 0, i;
for (i = length; i > 0; i--, reg++) {
ret = spi_reg_write(stmpe, reg, *(values + i - 1));
if (ret < 0)
return ret;
}
return ret;
}
static void spi_init(struct stmpe *stmpe)
{
struct spi_device *spi = stmpe->client;
spi->bits_per_word = 8;
/* This register is only present for stmpe811 */
if (stmpe->variant->id_val == 0x0811)
spi_reg_write(stmpe, STMPE811_REG_SPI_CFG, spi->mode);
if (spi_setup(spi) < 0)
dev_dbg(&spi->dev, "spi_setup failed\n");
}
static struct stmpe_client_info spi_ci = {
.read_byte = spi_reg_read,
.write_byte = spi_reg_write,
.read_block = spi_block_read,
.write_block = spi_block_write,
.init = spi_init,
};
static int
stmpe_spi_probe(struct spi_device *spi)
{
const struct spi_device_id *id = spi_get_device_id(spi);
/* don't exceed max specified rate - 1MHz - Limitation of STMPE */
if (spi->max_speed_hz > 1000000) {
dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
(spi->max_speed_hz/1000));
return -EINVAL;
}
spi_ci.irq = spi->irq;
spi_ci.client = spi;
spi_ci.dev = &spi->dev;
return stmpe_probe(&spi_ci, id->driver_data);
}
static void stmpe_spi_remove(struct spi_device *spi)
{
struct stmpe *stmpe = spi_get_drvdata(spi);
stmpe_remove(stmpe);
}
static const struct of_device_id stmpe_spi_of_match[] = {
{ .compatible = "st,stmpe610", },
{ .compatible = "st,stmpe801", },
{ .compatible = "st,stmpe811", },
{ .compatible = "st,stmpe1601", },
{ .compatible = "st,stmpe2401", },
{ .compatible = "st,stmpe2403", },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, stmpe_spi_of_match);
static const struct spi_device_id stmpe_spi_id[] = {
{ "stmpe610", STMPE610 },
{ "stmpe801", STMPE801 },
{ "stmpe811", STMPE811 },
{ "stmpe1601", STMPE1601 },
{ "stmpe2401", STMPE2401 },
{ "stmpe2403", STMPE2403 },
{ }
};
MODULE_DEVICE_TABLE(spi, stmpe_id);
static struct spi_driver stmpe_spi_driver = {
.driver = {
.name = "stmpe-spi",
.of_match_table = of_match_ptr(stmpe_spi_of_match),
.pm = pm_sleep_ptr(&stmpe_dev_pm_ops),
},
.probe = stmpe_spi_probe,
.remove = stmpe_spi_remove,
.id_table = stmpe_spi_id,
};
static int __init stmpe_init(void)
{
return spi_register_driver(&stmpe_spi_driver);
}
subsys_initcall(stmpe_init);
static void __exit stmpe_exit(void)
{
spi_unregister_driver(&stmpe_spi_driver);
}
module_exit(stmpe_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("STMPE MFD SPI Interface Driver");
MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");