Unverified Commit f5afdd13 authored by Naresh Solanki's avatar Naresh Solanki Committed by Mark Brown
Browse files

regulator (max5970): Add hwmon support 



Utilize the integrated 10-bit ADC in Max5970/Max5978 to enable voltage
and current monitoring. This feature is seamlessly integrated through
the hwmon subsystem.

Signed-off-by: default avatarNaresh Solanki <naresh.solanki@9elements.com>
Acked-by: default avatarGuenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20231027152830.1269895-1-naresh.solanki@9elements.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent ae61939c

drivers/regulator/max5970-regulator.c

+143 −1
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <linux/bitops.h>

#include <linux/device.h>

#include <linux/err.h>

#include <linux/hwmon.h>

#include <linux/module.h>

#include <linux/io.h>

#include <linux/of.h>
@@ -32,6 +33,132 @@ enum max597x_regulator_id { 
	MAX597X_SW1,

};



static int max5970_read_adc(struct regmap *regmap, int reg, long *val)

{

	u8 reg_data[2];

	int ret;



	ret = regmap_bulk_read(regmap, reg, &reg_data[0], 2);

	if (ret < 0)

		return ret;



	*val = (reg_data[0] << 2) | (reg_data[1] & 3);



	return 0;

}



static int max5970_read(struct device *dev, enum hwmon_sensor_types type,

			u32 attr, int channel, long *val)

{

	struct regulator_dev **rdevs = dev_get_drvdata(dev);

	struct max5970_regulator *ddata = rdev_get_drvdata(rdevs[channel]);

	struct regmap *regmap = ddata->regmap;

	int ret;



	switch (type) {

	case hwmon_curr:

		switch (attr) {

		case hwmon_curr_input:

			ret = max5970_read_adc(regmap, MAX5970_REG_CURRENT_H(channel), val);

			if (ret < 0)

				return ret;

			/*

			 * Calculate current from ADC value, IRNG range & shunt resistor value.

			 * ddata->irng holds the voltage corresponding to the maximum value the

			 * 10-bit ADC can measure.

			 * To obtain the output, multiply the ADC value by the IRNG range (in

			 * millivolts) and then divide it by the maximum value of the 10-bit ADC.

			 */

			*val = (*val * ddata->irng) >> 10;

			/* Convert the voltage meansurement across shunt resistor to current */

			*val = (*val * 1000) / ddata->shunt_micro_ohms;

			return 0;

		default:

			return -EOPNOTSUPP;

		}



	case hwmon_in:

		switch (attr) {

		case hwmon_in_input:

			ret = max5970_read_adc(regmap, MAX5970_REG_VOLTAGE_H(channel), val);

			if (ret < 0)

				return ret;

			/*

			 * Calculate voltage from ADC value and MON range.

			 * ddata->mon_rng holds the voltage corresponding to the maximum value the

			 * 10-bit ADC can measure.

			 * To obtain the output, multiply the ADC value by the MON range (in

			 * microvolts) and then divide it by the maximum value of the 10-bit ADC.

			 */

			*val = mul_u64_u32_shr(*val, ddata->mon_rng, 10);

			/* uV to mV */

			*val = *val / 1000;

			return 0;

		default:

			return -EOPNOTSUPP;

		}

	default:

		return -EOPNOTSUPP;

	}

}



static umode_t max5970_is_visible(const void *data,

				  enum hwmon_sensor_types type,

				  u32 attr, int channel)

{

	struct regulator_dev **rdevs = (struct regulator_dev **)data;

	struct max5970_regulator *ddata;



	if (channel >= MAX5970_NUM_SWITCHES || !rdevs[channel])

		return 0;



	ddata = rdev_get_drvdata(rdevs[channel]);



	if (channel >= ddata->num_switches)

		return 0;



	switch (type) {

	case hwmon_in:

		switch (attr) {

		case hwmon_in_input:

			return 0444;

		default:

			break;

		}

		break;

	case hwmon_curr:

		switch (attr) {

		case hwmon_curr_input:

			/* Current measurement requires knowledge of the shunt resistor value. */

			if (ddata->shunt_micro_ohms)

				return 0444;

			break;

		default:

			break;

		}

		break;

	default:

		break;

	}

	return 0;

}



static const struct hwmon_ops max5970_hwmon_ops = {

	.is_visible = max5970_is_visible,

	.read = max5970_read,

};



static const struct hwmon_channel_info *max5970_info[] = {

	HWMON_CHANNEL_INFO(in, HWMON_I_INPUT, HWMON_I_INPUT),

	HWMON_CHANNEL_INFO(curr, HWMON_C_INPUT, HWMON_C_INPUT),

	NULL

};



static const struct hwmon_chip_info max5970_chip_info = {

	.ops = &max5970_hwmon_ops,

	.info = max5970_info,

};



static int max597x_uvp_ovp_check_mode(struct regulator_dev *rdev, int severity)

{

	int ret, reg;
@@ -431,7 +558,8 @@ static int max597x_regulator_probe(struct platform_device *pdev) 
	struct i2c_client *i2c = to_i2c_client(pdev->dev.parent);

	struct regulator_config config = { };

	struct regulator_dev *rdev;

	struct regulator_dev *rdevs[MAX5970_NUM_SWITCHES];

	struct regulator_dev **rdevs = NULL;

	struct device *hwmon_dev;

	int num_switches;

	int ret, i;
@@ -442,6 +570,11 @@ static int max597x_regulator_probe(struct platform_device *pdev) 
	if (!max597x)

		return -ENOMEM;



	rdevs = devm_kcalloc(&i2c->dev, MAX5970_NUM_SWITCHES, sizeof(struct regulator_dev *),

			     GFP_KERNEL);

	if (!rdevs)

		return -ENOMEM;



	i2c_set_clientdata(i2c, max597x);



	if (of_device_is_compatible(i2c->dev.of_node, "maxim,max5978"))
@@ -485,6 +618,15 @@ static int max597x_regulator_probe(struct platform_device *pdev) 
		max597x->shunt_micro_ohms[i] = data->shunt_micro_ohms;

	}



	if (IS_REACHABLE(CONFIG_HWMON)) {

		hwmon_dev = devm_hwmon_device_register_with_info(&i2c->dev, "max5970", rdevs,

								 &max5970_chip_info, NULL);

		if (IS_ERR(hwmon_dev)) {

			return dev_err_probe(&i2c->dev, PTR_ERR(hwmon_dev),

					     "Unable to register hwmon device\n");

		}

	}



	if (i2c->irq) {

		ret =

		    max597x_setup_irq(&i2c->dev, i2c->irq, rdevs, num_switches,