diff options
Diffstat (limited to 'drivers/mfd/tps6594-spi.c')
| -rw-r--r-- | drivers/mfd/tps6594-spi.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/drivers/mfd/tps6594-spi.c b/drivers/mfd/tps6594-spi.c new file mode 100644 index 000000000..f4b4f37f9 --- /dev/null +++ b/drivers/mfd/tps6594-spi.c @@ -0,0 +1,129 @@ +// 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, -EINVAL, "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"); |