The PCA9450 PMIC by NXP can be communicated with via I2C; this driver uses that do determine the reset source that caused the PMIC to perform its latest power cycle.
Signed-off-by: Holger Assmann <[email protected]> --- drivers/mfd/Kconfig | 7 +++ drivers/mfd/Makefile | 1 + drivers/mfd/pca9450.c | 106 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 114 insertions(+) create mode 100644 drivers/mfd/pca9450.c diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index 39a40c2a3f..5189364c2c 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -69,6 +69,13 @@ config MFD_STPMIC1 help Select this to support communication with the STPMIC1. +config MFD_PCA9450 + depends on I2C + select REGMAP_I2C + bool "PCA9450 MFD driver" + help + Select this to support communication with the PCA9450 PMIC. + config MFD_RN568PMIC depends on I2C select REGMAP_I2C diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index f19bf53655..00f3eacf3c 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -25,3 +25,4 @@ obj-$(CONFIG_MFD_RK808) += rk808.o obj-$(CONFIG_MFD_AXP20X_I2C) += axp20x-i2c.o axp20x.o obj-$(CONFIG_MFD_ATMEL_SMC) += atmel-smc.o obj-$(CONFIG_MFD_ROHM_BD718XX) += rohm-bd718x7.o +obj-$(CONFIG_MFD_PCA9450) += pca9450.o diff --git a/drivers/mfd/pca9450.c b/drivers/mfd/pca9450.c new file mode 100644 index 0000000000..3e4a63f398 --- /dev/null +++ b/drivers/mfd/pca9450.c @@ -0,0 +1,106 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2023 Holger Assmann, Pengutronix + */ + +#include <common.h> +#include <driver.h> +#include <errno.h> +#include <i2c/i2c.h> +#include <init.h> +#include <mfd/pca9450.h> +#include <of.h> +#include <regmap.h> +#include <reset_source.h> + +#define REASON_PMIC_RST 0x10 +#define REASON_PWON 0x80 +#define REASON_SW_RST 0x20 +#define REASON_WDOG 0x40 + +static const struct regmap_config pca9450_regmap_i2c_config = { + .reg_bits = 8, + .val_bits = 8, + .max_register = 0x2E, +}; + +static int pca9450_get_reset_source(struct device *dev, struct regmap *map) +{ + enum reset_src_type type; + int reg; + int ret; + + ret = regmap_read(map, PCA9450_PWRON_STAT, ®); + if (ret) + return ret; + + switch (reg) { + case REASON_PWON: + dev_dbg(dev, "Power ON triggered by PMIC_ON_REQ.\n"); + type = RESET_POR; + break; + case REASON_WDOG: + dev_dbg(dev, "Detected cold reset by WDOGB pin\n"); + type = RESET_WDG; + break; + case REASON_SW_RST: + dev_dbg(dev, "Detected cold reset by SW_RST\n"); + type = RESET_RST; + break; + case REASON_PMIC_RST: + dev_dbg(dev, "Detected cold reset by PMIC_RST_B\n"); + type = RESET_EXT; + break; + default: + dev_warn(dev, "Could not determine reset reason.\n"); + type = RESET_UKWN; + } + + reset_source_set_device(dev, type); + + return 0; +}; + +static int __init pca9450_probe(struct device *dev) +{ + struct regmap *regmap; + int reg; + int ret; + + regmap = regmap_init_i2c(to_i2c_client(dev), &pca9450_regmap_i2c_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + ret = regmap_register_cdev(regmap, NULL); + if (ret) + return ret; + + ret = regmap_read(regmap, PCA9450_REG_DEV_ID, ®); + if (ret) { + dev_err(dev, "Unable to read PMIC Chip ID\n"); + return ret; + } + + /* Chip ID defined in bits [7:4] */ + dev_info(dev, "PMIC Chip ID: 0x%x\n", (reg >> 4)); + + pca9450_get_reset_source(dev,regmap); + + return of_platform_populate(dev->of_node, NULL, dev); +} + +static __maybe_unused struct of_device_id pca9450_dt_ids[] = { + { .compatible = "nxp,pca9450a" }, + { .compatible = "nxp,pca9450b" }, + { .compatible = "nxp,pca9450c" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, pca9450_dt_ids); + +static struct driver pca9450_i2c_driver = { + .name = "pca9450-i2c", + .probe = pca9450_probe, + .of_compatible = DRV_OF_COMPAT(pca9450_dt_ids), +}; + +coredevice_i2c_driver(pca9450_i2c_driver); -- 2.39.2
