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// SPDX-License-Identifier: GPL-2.0
/*
* SPI access driver for TI TPS6594/TPS6593/LP8764 PMICs
*
* Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/
*/
#include <linux/crc8.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/spi/spi.h>
#include <linux/mfd/tps6594.h>
#define TPS6594_SPI_PAGE_SHIFT 5
#define TPS6594_SPI_READ_BIT BIT(4)
static bool enable_crc;
module_param(enable_crc, bool, 0444);
MODULE_PARM_DESC(enable_crc, "Enable CRC feature for SPI interface");
DECLARE_CRC8_TABLE(tps6594_spi_crc_table);
static int tps6594_spi_reg_read(void *context, unsigned int reg, unsigned int *val)
{
struct spi_device *spi = context;
struct tps6594 *tps = spi_get_drvdata(spi);
u8 buf[4] = { 0 };
size_t count_rx = 1;
int ret;
buf[0] = reg;
buf[1] = TPS6594_REG_TO_PAGE(reg) << TPS6594_SPI_PAGE_SHIFT | TPS6594_SPI_READ_BIT;
if (tps->use_crc)
count_rx++;
ret = spi_write_then_read(spi, buf, 2, buf + 2, count_rx);
if (ret < 0)
return ret;
if (tps->use_crc && buf[3] != crc8(tps6594_spi_crc_table, buf, 3, CRC8_INIT_VALUE))
return -EIO;
*val = buf[2];
return 0;
}
static int tps6594_spi_reg_write(void *context, unsigned int reg, unsigned int val)
{
struct spi_device *spi = context;
struct tps6594 *tps = spi_get_drvdata(spi);
u8 buf[4] = { 0 };
size_t count = 3;
buf[0] = reg;
buf[1] = TPS6594_REG_TO_PAGE(reg) << TPS6594_SPI_PAGE_SHIFT;
buf[2] = val;
if (tps->use_crc)
buf[3] = crc8(tps6594_spi_crc_table, buf, count++, CRC8_INIT_VALUE);
return spi_write(spi, buf, count);
}
static const struct regmap_config tps6594_spi_regmap_config = {
.reg_bits = 16,
.val_bits = 8,
.max_register = TPS6594_REG_DWD_FAIL_CNT_REG,
.volatile_reg = tps6594_is_volatile_reg,
.reg_read = tps6594_spi_reg_read,
.reg_write = tps6594_spi_reg_write,
.use_single_read = true,
.use_single_write = true,
};
static const struct of_device_id tps6594_spi_of_match_table[] = {
{ .compatible = "ti,tps6594-q1", .data = (void *)TPS6594, },
{ .compatible = "ti,tps6593-q1", .data = (void *)TPS6593, },
{ .compatible = "ti,lp8764-q1", .data = (void *)LP8764, },
{}
};
MODULE_DEVICE_TABLE(of, tps6594_spi_of_match_table);
static int tps6594_spi_probe(struct spi_device *spi)
{
struct device *dev = &spi->dev;
struct tps6594 *tps;
const struct of_device_id *match;
tps = devm_kzalloc(dev, sizeof(*tps), GFP_KERNEL);
if (!tps)
return -ENOMEM;
spi_set_drvdata(spi, tps);
tps->dev = dev;
tps->reg = spi->chip_select;
tps->irq = spi->irq;
tps->regmap = devm_regmap_init(dev, NULL, spi, &tps6594_spi_regmap_config);
if (IS_ERR(tps->regmap))
return dev_err_probe(dev, PTR_ERR(tps->regmap), "Failed to init regmap\n");
match = of_match_device(tps6594_spi_of_match_table, dev);
if (!match)
return dev_err_probe(dev, PTR_ERR(match), "Failed to find matching chip ID\n");
tps->chip_id = (unsigned long)match->data;
crc8_populate_msb(tps6594_spi_crc_table, TPS6594_CRC8_POLYNOMIAL);
return tps6594_device_init(tps, enable_crc);
}
static struct spi_driver tps6594_spi_driver = {
.driver = {
.name = "tps6594",
.of_match_table = tps6594_spi_of_match_table,
},
.probe = tps6594_spi_probe,
};
module_spi_driver(tps6594_spi_driver);
MODULE_AUTHOR("Julien Panis <jpanis@baylibre.com>");
MODULE_DESCRIPTION("TPS6594 SPI Interface Driver");
MODULE_LICENSE("GPL");
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