[PATCH v2] mfd: regulator: initial support for pca9450

[Sascha Hauer]

On Fri, Sep 29, 2023 at 10:57:26AM +0200, Holger Assmann wrote:
> 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 <h.assmann at pengutronix.de>
> ---
> 
> Changes v1 -> v2:
> 
> 1. removed unnecessary whitespaces
> 2. code re-arrangement
> 
> ---
>  drivers/mfd/Kconfig   |   7 +++
>  drivers/mfd/Makefile  |   1 +
>  drivers/mfd/pca9450.c | 107 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 115 insertions(+)
>  create mode 100644 drivers/mfd/pca9450.c

Applied, thanks

Sascha

> 
> 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..929c4f68da
> --- /dev/null
> +++ b/drivers/mfd/pca9450.c
> @@ -0,0 +1,107 @@
> +// 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_SW_RST		0x20
> +#define REASON_WDOG		0x40
> +#define REASON_PWON		0x80
> +
> +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, &reg);
> +
> +	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, &reg);
> +
> +	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,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
> 
> 
> 

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