Re: [PATCH v5 4/5] regulator: p3h2x4x: Add driver for on-die regulators in NXP P3H2x4x i3c hub

[Frank Li <Frank.li@nxp.com>]

On Fri, Feb 06, 2026 at 02:01:20PM +0200, Aman Kumar Pandey wrote:
> The NXP P3H2x4x family integrates on-die regulators alongside I3C hub
> functionality. This driver registers the regulators using the MFD

Register the regulaltor ...

> framework and exposes them via the regulator subsystem.
>
> Signed-off-by: Aman Kumar Pandey <aman.kumarpandey@nxp.com>
> Signed-off-by: Vikash Bansal <vikash.bansal@nxp.com>
>
> ---
> Changes in v5:
>  - Updated dev_err_probe() for regmap_init failure.
>  - Updated module description
>
> Changes in v4:
>  - Split the driver into three separate patches (mfd, regulator and I3C hub)
>  - Introduced driver for on-die regulators in NXP P3H2x4x I3C hub
> ---
> ---
>  MAINTAINERS                                   |   1 +
>  drivers/regulator/Kconfig                     |  10 +
>  drivers/regulator/Makefile                    |   1 +
>  drivers/regulator/p3h2840_i3c_hub_regulator.c | 247 ++++++++++++++++++
>  4 files changed, 259 insertions(+)
>  create mode 100644 drivers/regulator/p3h2840_i3c_hub_regulator.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 6c247e4a0c12..6601830b6e86 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -18914,6 +18914,7 @@ L:	linux-i3c-owner@lists.infradead.org
>  S:	Maintained
>  F:	Documentation/devicetree/bindings/i3c/nxp,p3h2840.yaml
>  F:	drivers/mfd/p3h2840.c
> +F:	drivers/regulator/p3h2840_i3c_hub_regulator.c
>  F:	include/linux/mfd/p3h2840.h
>
>  NXP PF5300/PF5301/PF5302 PMIC REGULATOR DEVICE DRIVER
> diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
> index d2335276cce5..84684701dad7 100644
> --- a/drivers/regulator/Kconfig
> +++ b/drivers/regulator/Kconfig
> @@ -1010,6 +1010,16 @@ config REGULATOR_MTK_DVFSRC
>  	  of Mediatek. It allows for voting on regulator state
>  	  between multiple users.
>
> +config REGULATOR_P3H2X4X
> +       tristate "P3H2X4X regulator support"
> +       depends on MFD_P3H2X4X
> +       help
> +         This driver provides support for the voltage regulators of the
> +         P3H244x/P3H284x multi-function I3C Hub device.
> +
> +         Say M here if you want to include support for this regulator as
> +         a module. The module will be named "p3h2840_i3c_hub_regulator".
> +
>  config REGULATOR_PALMAS
>  	tristate "TI Palmas PMIC Regulators"
>  	depends on MFD_PALMAS
> diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
> index 1beba1493241..145138f437d8 100644
> --- a/drivers/regulator/Makefile
> +++ b/drivers/regulator/Makefile
> @@ -127,6 +127,7 @@ obj-$(CONFIG_REGULATOR_QCOM_RPMH) += qcom-rpmh-regulator.o
>  obj-$(CONFIG_REGULATOR_QCOM_SMD_RPM) += qcom_smd-regulator.o
>  obj-$(CONFIG_REGULATOR_QCOM_SPMI) += qcom_spmi-regulator.o
>  obj-$(CONFIG_REGULATOR_QCOM_USB_VBUS) += qcom_usb_vbus-regulator.o
> +obj-$(CONFIG_REGULATOR_P3H2X4X) += p3h2840_i3c_hub_regulator.o
>  obj-$(CONFIG_REGULATOR_PALMAS) += palmas-regulator.o
>  obj-$(CONFIG_REGULATOR_PCA9450) += pca9450-regulator.o
>  obj-$(CONFIG_REGULATOR_PF0900) += pf0900-regulator.o
> diff --git a/drivers/regulator/p3h2840_i3c_hub_regulator.c b/drivers/regulator/p3h2840_i3c_hub_regulator.c
> new file mode 100644
> index 000000000000..1e9abc398f5a
> --- /dev/null
> +++ b/drivers/regulator/p3h2840_i3c_hub_regulator.c
> @@ -0,0 +1,247 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2025 NXP
> + * This P3H2x4x driver file contain functions for enable/disable regulator and voltage set/get.
> + */
> +#include <linux/bitfield.h>
> +#include <linux/mfd/p3h2840.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/driver.h>
> +
> +#define P3H2x4x_LDO_AND_PULLUP_CONF				0x19
> +#define P3H2x4x_LDO_ENABLE_DISABLE_MASK				GENMASK(3, 0)
> +#define P3H2x4x_CP0_EN_LDO				        BIT(0)
> +#define P3H2x4x_CP1_EN_LDO				        BIT(1)
> +#define P3H2x4x_TP0145_EN_LDO					BIT(2)
> +#define P3H2x4x_TP2367_EN_LDO					BIT(3)
> +
> +#define P3H2x4x_NET_OPER_MODE_CONF				0x15
> +#define P3H2x4x_VCCIO_LDO_CONF					0x16
> +#define P3H2x4x_CP0_VCCIO_LDO_VOLTAGE_MASK			GENMASK(1, 0)
> +#define P3H2x4x_CP0_VCCIO_LDO_VOLTAGE(x)	\
> +		FIELD_PREP(P3H2x4x_CP0_VCCIO_LDO_VOLTAGE_MASK, x)
> +#define P3H2x4x_CP1_VCCIO_LDO_VOLTAGE_MASK			GENMASK(3, 2)
> +#define P3H2x4x_CP1_VCCIO_LDO_VOLTAGE(x)	\
> +		FIELD_PREP(P3H2x4x_CP1_VCCIO_LDO_VOLTAGE_MASK, x)
> +#define P3H2x4x_TP0145_VCCIO_LDO_VOLTAGE_MASK			GENMASK(5, 4)
> +#define P3H2x4x_TP0145_VCCIO_LDO_VOLTAGE(x)	\
> +		FIELD_PREP(P3H2x4x_TP0145_VCCIO_LDO_VOLTAGE_MASK, x)
> +#define P3H2x4x_TP2367_VCCIO_LDO_VOLTAGE_MASK			GENMASK(7, 6)
> +#define P3H2x4x_TP2367_VCCIO_LDO_VOLTAGE(x)	\
> +		FIELD_PREP(P3H2x4x_TP2367_VCCIO_LDO_VOLTAGE_MASK, x)
> +#define P3H2x4x_LDO_COUNT					4
> +
> +struct p3h2x4x_regulator_dev {
> +	struct regulator_dev *rp3h2x4x_dev[P3H2x4x_LDO_COUNT];
> +	struct regmap *regmap;
> +};
> +
> +static int p3h2x4x_regulator_enable(struct regulator_dev *rdev)
> +{
> +	int ret;
> +	unsigned int orig;
> +
> +	ret = regmap_read(rdev->regmap, P3H2x4x_DEV_REG_PROTECTION_CODE, &orig);
> +	if (ret)
> +		return ret;
> +
> +	if (orig != P3H2x4x_REGISTERS_UNLOCK_CODE) {
> +		ret = regmap_write(rdev->regmap, P3H2x4x_DEV_REG_PROTECTION_CODE,
> +				   P3H2x4x_REGISTERS_UNLOCK_CODE);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = regulator_enable_regmap(rdev);
> +	if (ret)
> +		return ret;

AI:
- If enable fails, protection register is left unlocked
- Should restore original state in error path

> +
> +	if (orig != P3H2x4x_REGISTERS_UNLOCK_CODE) {
> +		ret = regmap_write(rdev->regmap, P3H2x4x_DEV_REG_PROTECTION_CODE, orig);
> +		if (ret)
> +			return ret;
> +	}

AI:
- `p3h2x4x_regulator_enable()`, `_disable()`, and `_set_voltage_sel()` have identical unlock/lock logic
- Should extract to helper function

you can use cleanup to define macro, like mutex, use guard(...) to simple
code.

Frank
> +	return 0;
> +}
> +
> +static int p3h2x4x_regulator_disable(struct regulator_dev *rdev)
> +{
> +	int ret;
> +	unsigned int orig;
> +
> +	ret = regmap_read(rdev->regmap, P3H2x4x_DEV_REG_PROTECTION_CODE, &orig);
> +	if (ret)
> +		return ret;
> +
> +	if (orig != P3H2x4x_REGISTERS_UNLOCK_CODE) {
> +		ret = regmap_write(rdev->regmap, P3H2x4x_DEV_REG_PROTECTION_CODE,
> +				   P3H2x4x_REGISTERS_UNLOCK_CODE);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = regulator_disable_regmap(rdev);
> +	if (ret)
> +		return ret;
> +
> +	if (orig != P3H2x4x_REGISTERS_UNLOCK_CODE) {
> +		ret = regmap_write(rdev->regmap, P3H2x4x_DEV_REG_PROTECTION_CODE, orig);
> +		if (ret)
> +			return ret;
> +	}
> +	return 0;
> +}
> +
> +static int p3h2x4x_regulator_set_voltage_sel(struct regulator_dev *rdev, unsigned int sel)
> +{
> +	int ret;
> +	unsigned int orig;
> +
> +	ret = regmap_read(rdev->regmap, P3H2x4x_DEV_REG_PROTECTION_CODE, &orig);
> +	if (ret)
> +		return ret;
> +
> +	if (orig != P3H2x4x_REGISTERS_UNLOCK_CODE) {
> +		ret = regmap_write(rdev->regmap, P3H2x4x_DEV_REG_PROTECTION_CODE,
> +				   P3H2x4x_REGISTERS_UNLOCK_CODE);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = regulator_set_voltage_sel_regmap(rdev, sel);
> +	if (ret)
> +		return ret;
> +
> +	if (orig != P3H2x4x_REGISTERS_UNLOCK_CODE) {
> +		ret = regmap_write(rdev->regmap, P3H2x4x_DEV_REG_PROTECTION_CODE, orig);
> +		if (ret)
> +			return ret;
> +	}
> +	return 0;
> +}
> +
> +static const struct regulator_ops p3h2x4x_ldo_ops = {
> +	.list_voltage = regulator_list_voltage_table,
> +	.map_voltage = regulator_map_voltage_iterate,
> +	.set_voltage_sel = p3h2x4x_regulator_set_voltage_sel,
> +	.get_voltage_sel = regulator_get_voltage_sel_regmap,
> +	.enable = p3h2x4x_regulator_enable,
> +	.disable = p3h2x4x_regulator_disable,
> +	.is_enabled = regulator_is_enabled_regmap,
> +};
> +
> +static const unsigned int p3h2x4x_voltage_table[] = {
> +	1000000,
> +	1100000,
> +	1200000,
> +	1800000,
> +};
> +
> +static struct regulator_desc p3h2x4x_regulators[] = {
> +	{
> +		.name = "LDO_CP0",
> +		.of_match = of_match_ptr("LDO_CP0"),
> +		.regulators_node = of_match_ptr("regulators"),
> +		.volt_table = p3h2x4x_voltage_table,
> +		.n_voltages = ARRAY_SIZE(p3h2x4x_voltage_table),
> +		.ops = &p3h2x4x_ldo_ops,
> +		.type = REGULATOR_VOLTAGE,
> +		.owner = THIS_MODULE,
> +		.enable_reg = P3H2x4x_LDO_AND_PULLUP_CONF,
> +		.enable_mask = P3H2x4x_CP0_EN_LDO,
> +		.vsel_reg = P3H2x4x_VCCIO_LDO_CONF,
> +		.vsel_mask = P3H2x4x_CP0_VCCIO_LDO_VOLTAGE_MASK,
> +	},
> +	{
> +		.name = "LDO_CP1",
> +		.of_match = of_match_ptr("LDO_CP1"),
> +		.regulators_node = of_match_ptr("regulators"),
> +		.volt_table = p3h2x4x_voltage_table,
> +		.n_voltages = ARRAY_SIZE(p3h2x4x_voltage_table),
> +		.ops = &p3h2x4x_ldo_ops,
> +		.type = REGULATOR_VOLTAGE,
> +		.owner = THIS_MODULE,
> +		.enable_reg = P3H2x4x_LDO_AND_PULLUP_CONF,
> +		.enable_mask = P3H2x4x_CP1_EN_LDO,
> +		.vsel_reg = P3H2x4x_VCCIO_LDO_CONF,
> +		.vsel_mask = P3H2x4x_CP1_VCCIO_LDO_VOLTAGE_MASK,
> +	},
> +	{
> +		.name = "LDO_TPG0",
> +		.of_match = of_match_ptr("LDO_TPG0"),
> +		.regulators_node = of_match_ptr("regulators"),
> +		.volt_table = p3h2x4x_voltage_table,
> +		.n_voltages = ARRAY_SIZE(p3h2x4x_voltage_table),
> +		.ops = &p3h2x4x_ldo_ops,
> +		.type = REGULATOR_VOLTAGE,
> +		.owner = THIS_MODULE,
> +		.enable_reg = P3H2x4x_LDO_AND_PULLUP_CONF,
> +		.enable_mask = P3H2x4x_TP0145_EN_LDO,
> +		.vsel_reg = P3H2x4x_VCCIO_LDO_CONF,
> +		.vsel_mask = P3H2x4x_TP0145_VCCIO_LDO_VOLTAGE_MASK,
> +	},
> +	{
> +		.name = "LDO_TPG1",
> +		.of_match = of_match_ptr("LDO_TPG1"),
> +		.regulators_node = of_match_ptr("regulators"),
> +		.volt_table = p3h2x4x_voltage_table,
> +		.n_voltages = ARRAY_SIZE(p3h2x4x_voltage_table),
> +		.ops = &p3h2x4x_ldo_ops,
> +		.type = REGULATOR_VOLTAGE,
> +		.owner = THIS_MODULE,
> +		.enable_reg = P3H2x4x_LDO_AND_PULLUP_CONF,
> +		.enable_mask = P3H2x4x_TP2367_EN_LDO,
> +		.vsel_reg = P3H2x4x_VCCIO_LDO_CONF,
> +		.vsel_mask = P3H2x4x_TP2367_VCCIO_LDO_VOLTAGE_MASK,
> +	},
> +};
> +
> +static int p3h2x4x_regulator_probe(struct platform_device *pdev)
> +{
> +	struct p3h2x4x_dev *p3h2x4x = dev_get_drvdata(pdev->dev.parent);
> +	struct p3h2x4x_regulator_dev *p3h2x4x_regulator;
> +	struct regulator_config rcfg = { };
> +	struct device *dev = &pdev->dev;
> +	struct regulator_dev *rdev;
> +	int ret, i;
> +
> +	p3h2x4x_regulator = devm_kzalloc(dev, sizeof(*p3h2x4x_regulator), GFP_KERNEL);
> +	if (!p3h2x4x_regulator)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, p3h2x4x_regulator);
> +
> +	p3h2x4x_regulator->regmap = p3h2x4x->regmap;
> +	device_set_of_node_from_dev(dev, dev->parent);
> +
> +	rcfg.dev = dev;
> +	rcfg.dev->of_node = dev->of_node;
> +	rcfg.regmap = p3h2x4x_regulator->regmap;
> +	rcfg.driver_data = p3h2x4x_regulator;
> +
> +	for (i = 0; i < ARRAY_SIZE(p3h2x4x_regulators); i++) {
> +		rdev = devm_regulator_register(&pdev->dev, &p3h2x4x_regulators[i], &rcfg);
> +		if (IS_ERR(rdev)) {
> +			return dev_err_probe(dev, PTR_ERR(rdev), "Failed to register %s\n",
> +					     p3h2x4x_regulators[i].name);
> +		}
> +		p3h2x4x_regulator->rp3h2x4x_dev[i] = rdev;
> +	}
> +	return 0;
> +}
> +
> +static struct platform_driver p3h2x4x_regulator_driver = {
> +	.driver = {
> +		.name = "p3h2x4x-regulator",
> +		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
> +	},
> +	.probe = p3h2x4x_regulator_probe,
> +};
> +module_platform_driver(p3h2x4x_regulator_driver);
> +
> +MODULE_AUTHOR("Aman Kumar Pandey <aman.kumarpandey@nxp.com>");
> +MODULE_AUTHOR("vikash Bansal <vikash.bansal@nxp.com>");
> +MODULE_DESCRIPTION("P3H2x4x I3C HUB Regulator driver");
> +MODULE_LICENSE("GPL");
> --
> 2.25.1
>