This driver allows reading some regulator settings and adjusting
output voltage. It is based on information from the datasheet
at https://www.nxp.com/docs/en/data-sheet/PF5300.pdf

Signed-off-by: Woodrow Douglass <wdouglass@carnegierobotics.com>
---
 MAINTAINERS                          |   6 +
 drivers/regulator/Kconfig            |  12 +
 drivers/regulator/Makefile           |   1 +
 drivers/regulator/pf530x-regulator.c | 328 +++++++++++++++++++++++++++
 4 files changed, 347 insertions(+)
 create mode 100644 drivers/regulator/pf530x-regulator.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 6dcfbd11efef..2c2d165a40ff 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18291,6 +18291,12 @@ F:	Documentation/devicetree/bindings/clock/*imx*
 F:	drivers/clk/imx/
 F:	include/dt-bindings/clock/*imx*
 
+NXP PF5300/PF5301/PF5302 PMIC REGULATOR DEVICE DRIVER
+M:	Woodrow Douglass <wdouglass@carnegierobotics.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/regulator/nxp,pf530x-regulator.yaml
+F:	drivers/regulator/pf530x-regulator.c
+
 NXP PF8100/PF8121A/PF8200 PMIC REGULATOR DEVICE DRIVER
 M:	Jagan Teki <jagan@amarulasolutions.com>
 S:	Maintained
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index eaa6df1c9f80..611356bea09d 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -1006,6 +1006,18 @@ config REGULATOR_PCAP
 	 This driver provides support for the voltage regulators of the
 	 PCAP2 PMIC.
 
+config REGULATOR_PF530X
+	tristate "NXP PF5300/PF5301/PF5302 regulator driver"
+	depends on I2C && OF
+	select REGMAP_I2C
+	help
+	  Say y here to support the regulators found on the NXP
+	  PF5300/PF5301/PF5302 PMIC.
+
+	  Say M here if you want to support for the regulators found
+	  on the NXP PF5300/PF5301/PF5302 PMIC. The module will be named
+	  "pf530x-regulator".
+
 config REGULATOR_PF8X00
 	tristate "NXP PF8100/PF8121A/PF8200 regulator driver"
 	depends on I2C && OF
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index be98b29d6675..60ca55d04aef 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -125,6 +125,7 @@ obj-$(CONFIG_REGULATOR_QCOM_USB_VBUS) += qcom_usb_vbus-regulator.o
 obj-$(CONFIG_REGULATOR_PALMAS) += palmas-regulator.o
 obj-$(CONFIG_REGULATOR_PCA9450) += pca9450-regulator.o
 obj-$(CONFIG_REGULATOR_PF9453) += pf9453-regulator.o
+obj-$(CONFIG_REGULATOR_PF530X) += pf530x-regulator.o
 obj-$(CONFIG_REGULATOR_PF8X00) += pf8x00-regulator.o
 obj-$(CONFIG_REGULATOR_PFUZE100) += pfuze100-regulator.o
 obj-$(CONFIG_REGULATOR_PV88060) += pv88060-regulator.o
diff --git a/drivers/regulator/pf530x-regulator.c b/drivers/regulator/pf530x-regulator.c
new file mode 100644
index 000000000000..51c99d68413e
--- /dev/null
+++ b/drivers/regulator/pf530x-regulator.c
@@ -0,0 +1,328 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+//documentation of this device is available at
+//https://www.nxp.com/docs/en/data-sheet/PF5300.pdf
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/consumer.h>
+#include <linux/regulator/machine.h>
+
+/* registers */
+#define PF530X_DEVICEID			0x00
+#define PF530X_REVID			0x01
+#define PF530X_EMREV			0x02
+#define PF530X_PROGID			0x03
+#define PF530X_CONFIG1			0x04
+#define PF530X_INT_STATUS1		0x05
+#define PF530X_INT_SENSE1		0x06
+#define PF530X_INT_STATUS2		0x07
+#define PF530X_INT_SENSE2		0x08
+#define PF530X_BIST_STAT1		0x09
+#define PF530X_BIST_CTRL		0x0a
+#define PF530X_STATE			0x0b
+#define PF530X_STATE_CTRL		0x0c
+#define PF530X_SW1_VOLT			0x0d
+#define PF530X_SW1_STBY_VOLT	0x0e
+#define PF530X_SW1_CTRL1		0x0f
+#define PF530X_SW1_CTRL2		0x10
+#define PF530X_CLK_CTRL			0x11
+#define PF530X_SEQ_CTRL1		0x12
+#define PF530X_SEQ_CTRL2		0x13
+#define PF530X_RANDOM_CHK		0x14
+#define PF530X_RANDOM_GEN		0x15
+#define PF530X_WD_CTRL1			0x16
+#define PF530X_WD_SEED			0x17
+#define PF530X_WD_ANSWER		0x18
+#define PF530X_FLT_CNT1			0x19
+#define PF530X_FLT_CNT2			0x1a
+#define PF530X_OTP_MODE			0x2f
+
+enum pf530x_states {
+	PF530X_STATE_POF,
+	PF530X_STATE_FUSE_LOAD,
+	PF530X_STATE_LP_OFF,
+	PF530X_STATE_SELF_TEST,
+	PF530X_STATE_POWER_UP,
+	PF530X_STATE_INIT,
+	PF530X_STATE_IO_RELEASE,
+	PF530X_STATE_RUN,
+	PF530X_STATE_STANDBY,
+	PF530X_STATE_FAULT,
+	PF530X_STATE_FAILSAFE,
+	PF530X_STATE_POWER_DOWN,
+	PF530X_STATE_2MS_SELFTEST_RETRY,
+	PF530X_STATE_OFF_DLY,
+};
+
+#define PF530_FAM			0x50
+enum pf530x_devid {
+	PF5300			= 0x3,
+	PF5301			= 0x4,
+	PF5302			= 0x5,
+};
+
+#define PF530x_FAM			0x50
+#define PF530x_DEVICE_FAM_MASK		GENMASK(7, 4)
+#define PF530x_DEVICE_ID_MASK		GENMASK(3, 0)
+
+#define PF530x_STATE_MASK		GENMASK(3, 0)
+#define PF530x_STATE_RUN		0x07
+#define PF530x_STATE_STANDBY	0x08
+#define PF530x_STATE_LP_OFF		0x02
+
+#define PF530X_OTP_STBY_MODE	GENMASK(3, 2)
+#define PF530X_OTP_RUN_MODE		GENMASK(1, 0)
+
+#define PF530X_INT_STATUS_OV	BIT(1)
+#define PF530X_INT_STATUS_UV	BIT(2)
+#define PF530X_INT_STATUS_ILIM	BIT(3)
+
+struct pf530x_chip {
+	struct regmap *regmap;
+	struct device *dev;
+};
+
+static const struct regmap_config pf530x_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = PF530X_OTP_MODE,
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static int pf530x_is_enabled(struct regulator_dev *rdev)
+{
+	//first get mode
+	unsigned int state;
+	unsigned int mode;
+	int ret;
+
+	ret = regmap_read(rdev->regmap, PF530X_STATE, &state);
+	if (ret != 0)
+		return ret;
+
+	state &= PF530x_STATE_MASK;
+
+	ret = regmap_read(rdev->regmap, PF530X_OTP_MODE, &mode);
+	if (ret != 0)
+		return ret;
+
+	//are we enabled in that mode?
+	switch (state) {
+	case PF530x_STATE_RUN:
+		ret = ((mode & PF530X_OTP_RUN_MODE) == 0);
+		break;
+	case PF530x_STATE_STANDBY:
+		ret = ((mode & PF530X_OTP_STBY_MODE) == 0);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+	return ret;
+}
+
+static int pf530x_get_status(struct regulator_dev *rdev)
+{
+	unsigned int state;
+	int ret;
+
+	ret = regmap_read(rdev->regmap, PF530X_STATE, &state);
+	if (ret != 0)
+		return ret;
+
+	state &= PF530x_STATE_MASK;
+
+	switch (state) {
+	case PF530x_STATE_RUN:
+		ret = REGULATOR_STATUS_NORMAL;
+		break;
+	case PF530x_STATE_STANDBY:
+		ret = REGULATOR_STATUS_STANDBY;
+		break;
+	case PF530x_STATE_LP_OFF:
+		ret = REGULATOR_STATUS_OFF;
+		break;
+	default:
+		ret = REGULATOR_STATUS_ERROR;
+		break;
+	}
+	return ret;
+}
+
+static int pf530x_get_error_flags(struct regulator_dev *rdev, unsigned int *flags)
+{
+	unsigned int status;
+	int ret;
+
+	ret = regmap_read(rdev->regmap, PF530X_INT_STATUS1, &status);
+
+	if (ret != 0)
+		return ret;
+
+	*flags = 0;
+
+	if (status & PF530X_INT_STATUS_OV)
+		*flags |= REGULATOR_ERROR_OVER_VOLTAGE_WARN;
+
+	if (status & PF530X_INT_STATUS_UV)
+		*flags |= REGULATOR_ERROR_UNDER_VOLTAGE;
+
+	if (status & PF530X_INT_STATUS_ILIM)
+		*flags |= REGULATOR_ERROR_OVER_CURRENT;
+
+	return 0;
+}
+
+static const struct regulator_ops pf530x_regulator_ops = {
+	.enable = regulator_enable_regmap,
+	.disable = regulator_disable_regmap,
+	.is_enabled = pf530x_is_enabled,
+	.map_voltage = regulator_map_voltage_linear_range,
+	.list_voltage = regulator_list_voltage_linear_range,
+	.set_voltage_sel = regulator_set_voltage_sel_regmap,
+	.get_voltage_sel = regulator_get_voltage_sel_regmap,
+	.get_status = pf530x_get_status,
+	.get_error_flags = pf530x_get_error_flags,
+	.set_bypass = regulator_set_bypass_regmap,
+	.get_bypass = regulator_get_bypass_regmap,
+};
+
+static struct linear_range vrange = REGULATOR_LINEAR_RANGE(500000, 0, 140, 5000);
+
+static struct regulator_desc pf530x_reg_desc = {
+	.name = "SW1",
+	.of_match = of_match_ptr("SW1"),
+	.regulators_node = "regulators",
+	.ops = &pf530x_regulator_ops,
+	.linear_ranges = &vrange,
+	.n_linear_ranges = 1,
+	.type = REGULATOR_VOLTAGE,
+	.id = 0,
+	.owner = THIS_MODULE,
+	.vsel_reg = PF530X_SW1_VOLT,
+	.vsel_mask = 0xFF,
+	.bypass_reg = PF530X_SW1_CTRL2,
+	.bypass_mask = 0x07,
+	.bypass_val_on = 0x07,
+	.bypass_val_off = 0x00,
+};
+
+static int pf530x_identify(struct pf530x_chip *chip)
+{
+	unsigned int value;
+	u8 dev_fam, dev_id;
+	const char *name = NULL;
+	int ret;
+
+	ret = regmap_read(chip->regmap, PF530X_DEVICEID, &value);
+	if (ret) {
+		dev_err(chip->dev, "failed to read chip family\n");
+		return ret;
+	}
+
+	dev_fam = value & PF530x_DEVICE_FAM_MASK;
+	switch (dev_fam) {
+	case PF530x_FAM:
+		break;
+	default:
+		dev_err(chip->dev,
+			"Chip 0x%x is not from PF530X family\n", dev_fam);
+		return ret;
+	}
+
+	dev_id = value & PF530x_DEVICE_ID_MASK;
+	switch (dev_id) {
+	case PF5300:
+		name = "PF5300";
+		break;
+	case PF5301:
+		name = "PF5301";
+		break;
+	case PF5302:
+		name = "PF5302";
+		break;
+	default:
+		dev_err(chip->dev, "Unknown pf530x device id 0x%x\n", dev_id);
+		return -ENODEV;
+	}
+
+	dev_info(chip->dev, "%s Regulator found.\n", name);
+
+	return 0;
+}
+
+static int pf530x_i2c_probe(struct i2c_client *client)
+{
+	struct regulator_config config = { NULL, };
+	struct pf530x_chip *chip;
+	int ret;
+	struct regulator_dev *rdev;
+
+	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, chip);
+	chip->dev = &client->dev;
+
+	chip->regmap = devm_regmap_init_i2c(client, &pf530x_regmap_config);
+	if (IS_ERR(chip->regmap)) {
+		ret = PTR_ERR(chip->regmap);
+		dev_err(&client->dev,
+			"regmap allocation failed with err %d\n", ret);
+		return ret;
+	}
+
+	ret = pf530x_identify(chip);
+	if (ret)
+		return ret;
+
+	config.dev = chip->dev;
+	config.driver_data = &pf530x_reg_desc;
+	config.regmap = chip->regmap;
+
+	//the config parameter gets copied, it's ok to pass a pointer on the stack here
+	rdev = devm_regulator_register(&client->dev, &pf530x_reg_desc, &config);
+	if (IS_ERR(rdev)) {
+		dev_err(&client->dev, "failed to register %s regulator\n", pf530x_reg_desc.name);
+		return PTR_ERR(rdev);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id pf530x_dt_ids[] = {
+	{ .compatible = "nxp,pf5300",},
+	{ .compatible = "nxp,pf5301",},
+	{ .compatible = "nxp,pf5302",},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, pf530x_dt_ids);
+
+static const struct i2c_device_id pf530x_i2c_id[] = {
+	{ "pf5300", 0 },
+	{ "pf5301", 0 },
+	{ "pf5302", 0 },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, pf530x_i2c_id);
+
+static struct i2c_driver pf530x_regulator_driver = {
+	.id_table = pf530x_i2c_id,
+	.driver = {
+		.name = "pf530x",
+		.of_match_table = pf530x_dt_ids,
+	},
+	.probe_new = pf530x_i2c_probe,
+};
+module_i2c_driver(pf530x_regulator_driver);
+
+MODULE_AUTHOR("Woodrow Douglass <wdouglass@carnegierobotics.com>");
+MODULE_DESCRIPTION("Regulator Driver for NXP's PF5300/PF5301/PF5302 PMIC");
+MODULE_LICENSE("GPL");
-- 
2.39.5

On Tue, Sep 02, 2025 at 10:21:33AM -0400, Woodrow Douglass wrote:

>  obj-$(CONFIG_REGULATOR_PALMAS) += palmas-regulator.o
>  obj-$(CONFIG_REGULATOR_PCA9450) += pca9450-regulator.o
>  obj-$(CONFIG_REGULATOR_PF9453) += pf9453-regulator.o
> +obj-$(CONFIG_REGULATOR_PF530X) += pf530x-regulator.o
>  obj-$(CONFIG_REGULATOR_PF8X00) += pf8x00-regulator.o
>  obj-$(CONFIG_REGULATOR_PFUZE100) += pfuze100-regulator.o
>  obj-$(CONFIG_REGULATOR_PV88060) += pv88060-regulator.o

I'd say please keep this sorted but there's some cleanup needed here
already so whatever, let's deal with that separately.

> +static const struct regmap_config pf530x_regmap_config = {
> +       .reg_bits = 8,
> +       .val_bits = 8,
> +       .max_register = PF530X_OTP_MODE,
> +       .cache_type = REGCACHE_RBTREE,
> +};

In general it's better to use _MAPLE register caches unless you've got a
good reason not to, the data structure is more modern.

> +static int pf530x_is_enabled(struct regulator_dev *rdev)
> +{
> +	//first get mode

Usual comment style would have a space after the //.

> +static int pf530x_get_status(struct regulator_dev *rdev)
> +{

I would have expected this function to check INT_SENSE1/2 for current
error statuses and report those.

> +static int pf530x_get_error_flags(struct regulator_dev *rdev, unsigned int *flags)

I see INT_STATUS2 has thermal warning/error interrupts in it as well.
Not essential but it'd be nice to also check those.  These statuses are
also clear on write so I'd expect a write to clear them, even though the
device lacks an actual interrupt line so it's all somewhat ornamantal
ATM :/  I suppse we ought to implement some core thing to do polling for
non-interrupting regulators, but that's definitely out of scope for this
driver.

> +static const struct regulator_ops pf530x_regulator_ops = {
> +	.enable = regulator_enable_regmap,
> +	.disable = regulator_disable_regmap,
> +	.is_enabled = pf530x_is_enabled,

The custom is_enabled() operation doesn't seem to line up with the
generic regmap enable/disable operations, and we don't seem to have
enable_val or disable_val in the regulator_desc which the generic ops
expect.  The whole connection with the modes seems a bit odd, the
standby voltages look like they'd more naturally map to the regulator
API's suspend mode but perhaps these devices are not usually integrated
in that way and this would be controlled separately to system suspend.

> +static int pf530x_identify(struct pf530x_chip *chip)
> +{

> +	dev_info(chip->dev, "%s Regulator found.\n", name);

It wouldn't hurt to read and log the data in REV, EMREV and PROG_ID too
(it can be helpful when debugging).