hwmon: Add TSC1641 I2C power monitor driver (0c7d530a) · Commits · git / linux-net

Documentation/hwmon/index.rst

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		@@ -256,6 +256,7 @@ Hardware Monitoring Kernel Drivers
		tps40422
		tps53679
		tps546d24
		tsc1641
		twl4030-madc-hwmon
		ucd9000
		ucd9200

Documentation/hwmon/tsc1641.rst

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		.. SPDX-License-Identifier: GPL-2.0-only

		Kernel driver tsc1641
		=====================

		Supported chips:

		* ST TSC1641

		Prefix: 'tsc1641'

		Addresses scanned: -

		Datasheet:
		https://www.st.com/resource/en/datasheet/tsc1641.pdf

		Author:
		- Igor Reznichenko <igor@reznichenko.net>


		Description
		-----------

		The TSC1641 is a high-precision current, voltage, power, and temperature
		monitoring analog front-end (AFE). It monitors bidirectional current into a
		shunt resistor and load voltage up to 60 V in a synchronized way. Digital bus
		interface is I2C/SMbus. The TSC1641 allows the assertion of several alerts
		regarding the voltage, current, power and temperature.

		Usage Notes
		-----------

		The TSC1641 driver requires the value of the external shunt resistor to
		correctly compute current and power measurements. The resistor value, in
		micro-ohms, should be provided either through the device tree property
		"shunt-resistor-micro-ohms" or via writable sysfs attribute "shunt_resistor".
		Please refer to the Documentation/devicetree/bindings/hwmon/st,tsc1641.yaml
		for bindings if the device tree is used.

		Supported range of shunt resistor values is from 100 uOhm to 655.35 mOhm, in
		10 uOhm steps.
		When selecting the value keep in mind device maximum DC power measurement is
		1600W. See datasheet p.22 for ST recommendations on selecting shunt value.

		If the shunt resistor value is not specified in the device tree, the driver
		initializes it to 1000 uOhm by default. Users may configure the correct shunt
		resistor value at runtime by writing to the "shunt_resistor" sysfs attribute.

		The driver only supports continuous operating mode.
		Measurement ranges:

		================ ===============================================================
		Current Bidirectional, dependent on shunt
		Bus voltage 0-60V
		Maximum DC power 1600W
		Temperature -40C to +125C
		================ ===============================================================

		Sysfs entries
		-------------

		==================== ===========================================================
		in0_input bus voltage (mV)
		in0_max bus voltage max alarm limit (mV)
		in0_max_alarm bus voltage max alarm limit exceeded
		in0_min bus voltage min alarm limit (mV)
		in0_min_alarm bus voltage min alarm limit exceeded

		curr1_input current measurement (mA)
		curr1_max current max alarm limit (mA)
		curr1_max_alarm current max alarm limit exceeded
		curr1_min current min alarm limit (mA)
		curr1_min_alarm current min alarm limit exceeded

		power1_input power measurement (uW)
		power1_max power max alarm limit (uW)
		power1_max_alarm power max alarm limit exceeded

		shunt_resistor shunt resistor value (uOhms)

		temp1_input temperature measurement (mdegC)
		temp1_max temperature max alarm limit (mdegC)
		temp1_max_alarm temperature max alarm limit exceeded

		update_interval data conversion time (1 - 33ms), longer conversion time
		corresponds to higher effective resolution in bits
		==================== ===========================================================
		No newline at end of file

drivers/hwmon/Kconfig

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		@@ -2434,6 +2434,18 @@ config SENSORS_TMP513
		This driver can also be built as a module. If so, the module
		will be called tmp513.

		config SENSORS_TSC1641
		tristate "ST Microelectronics TSC1641 Power Monitor"
		depends on I2C
		select REGMAP_I2C
		help
		If you say yes here you get support for TSC1641 power monitor chip.
		The TSC1641 driver is configured for the default configuration of
		the part except temperature is enabled by default.

		This driver can also be built as a module. If so, the module
		will be called tsc1641.

		config SENSORS_VEXPRESS
		tristate "Versatile Express"
		depends on VEXPRESS_CONFIG

drivers/hwmon/Makefile

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		@@ -233,6 +233,7 @@ obj-$(CONFIG_SENSORS_TMP401) += tmp401.o
		obj-$(CONFIG_SENSORS_TMP421) += tmp421.o
		obj-$(CONFIG_SENSORS_TMP464) += tmp464.o
		obj-$(CONFIG_SENSORS_TMP513) += tmp513.o
		obj-$(CONFIG_SENSORS_TSC1641) += tsc1641.o
		obj-$(CONFIG_SENSORS_VEXPRESS) += vexpress-hwmon.o
		obj-$(CONFIG_SENSORS_VIA_CPUTEMP)+= via-cputemp.o
		obj-$(CONFIG_SENSORS_VIA686A) += via686a.o

drivers/hwmon/tsc1641.c

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		// SPDX-License-Identifier: GPL-2.0
		/*
		* Driver for ST Microelectronics TSC1641 I2C power monitor
		*
		* 60 V, 16-bit high-precision power monitor with I2C and MIPI I3C interface
		* Datasheet: https://www.st.com/resource/en/datasheet/tsc1641.pdf
		*
		* Copyright (C) 2025 Igor Reznichenko <igor@reznichenko.net>
		*/

		#include <linux/bitfield.h>
		#include <linux/bits.h>
		#include <linux/device.h>
		#include <linux/err.h>
		#include <linux/hwmon.h>
		#include <linux/i2c.h>
		#include <linux/module.h>
		#include <linux/regmap.h>
		#include <linux/sysfs.h>
		#include <linux/util_macros.h>

		/* I2C registers */
		#define TSC1641_CONFIG 0x00
		#define TSC1641_SHUNT_VOLTAGE 0x01
		#define TSC1641_LOAD_VOLTAGE 0x02
		#define TSC1641_POWER 0x03
		#define TSC1641_CURRENT 0x04
		#define TSC1641_TEMP 0x05
		#define TSC1641_MASK 0x06
		#define TSC1641_FLAG 0x07
		#define TSC1641_RSHUNT 0x08 /* Shunt resistance */
		#define TSC1641_SOL 0x09
		#define TSC1641_SUL 0x0A
		#define TSC1641_LOL 0x0B
		#define TSC1641_LUL 0x0C
		#define TSC1641_POL 0x0D
		#define TSC1641_TOL 0x0E
		#define TSC1641_MANUF_ID 0xFE /* 0x0006 */
		#define TSC1641_DIE_ID 0xFF /* 0x1000 */
		#define TSC1641_MAX_REG 0xFF

		#define TSC1641_RSHUNT_DEFAULT 1000 /* 1mOhm */
		#define TSC1641_CONFIG_DEFAULT 0x003F /* Default mode and temperature sensor */
		#define TSC1641_MASK_DEFAULT 0xFC00 /* Unmask all alerts */

		/* Bit mask for conversion time in the configuration register */
		#define TSC1641_CONV_TIME_MASK GENMASK(7, 4)

		#define TSC1641_CONV_TIME_DEFAULT 1024
		#define TSC1641_MIN_UPDATE_INTERVAL 1024

		/* LSB value of different registers */
		#define TSC1641_VLOAD_LSB_MVOLT 2
		#define TSC1641_POWER_LSB_UWATT 25000
		#define TSC1641_VSHUNT_LSB_NVOLT 2500 /* Use nanovolts to make it integer */
		#define TSC1641_RSHUNT_LSB_UOHM 10
		#define TSC1641_TEMP_LSB_MDEGC 500

		/* Limits based on datasheet */
		#define TSC1641_RSHUNT_MIN_UOHM 100
		#define TSC1641_RSHUNT_MAX_UOHM 655350
		#define TSC1641_CURR_ABS_MAX_MAMP 819200 /* Max current at 100uOhm*/

		#define TSC1641_ALERT_POL_MASK BIT(1)
		#define TSC1641_ALERT_LATCH_EN_MASK BIT(0)

		/* Flags indicating alerts in TSC1641_FLAG register*/
		#define TSC1641_SAT_FLAG BIT(13)
		#define TSC1641_SHUNT_OV_FLAG BIT(6)
		#define TSC1641_SHUNT_UV_FLAG BIT(5)
		#define TSC1641_LOAD_OV_FLAG BIT(4)
		#define TSC1641_LOAD_UV_FLAG BIT(3)
		#define TSC1641_POWER_OVER_FLAG BIT(2)
		#define TSC1641_TEMP_OVER_FLAG BIT(1)

		static bool tsc1641_writeable_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case TSC1641_CONFIG:
		case TSC1641_MASK:
		case TSC1641_RSHUNT:
		case TSC1641_SOL:
		case TSC1641_SUL:
		case TSC1641_LOL:
		case TSC1641_LUL:
		case TSC1641_POL:
		case TSC1641_TOL:
		return true;
		default:
		return false;
		}
		}

		static bool tsc1641_volatile_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case TSC1641_SHUNT_VOLTAGE:
		case TSC1641_LOAD_VOLTAGE:
		case TSC1641_POWER:
		case TSC1641_CURRENT:
		case TSC1641_TEMP:
		case TSC1641_FLAG:
		case TSC1641_MANUF_ID:
		case TSC1641_DIE_ID:
		return true;
		default:
		return false;
		}
		}

		static const struct regmap_config tsc1641_regmap_config = {
		.reg_bits = 8,
		.val_bits = 16,
		.use_single_write = true,
		.use_single_read = true,
		.max_register = TSC1641_MAX_REG,
		.cache_type = REGCACHE_MAPLE,
		.volatile_reg = tsc1641_volatile_reg,
		.writeable_reg = tsc1641_writeable_reg,
		};

		struct tsc1641_data {
		long rshunt_uohm;
		long current_lsb_ua;
		struct regmap *regmap;
		};

		/*
		* Upper limit due to chip 16-bit shunt register, lower limit to
		* prevent current and power registers overflow
		*/
		static inline int tsc1641_validate_shunt(u32 val)
		{
		if (val < TSC1641_RSHUNT_MIN_UOHM \|\| val > TSC1641_RSHUNT_MAX_UOHM)
		return -EINVAL;
		return 0;
		}

		static int tsc1641_set_shunt(struct tsc1641_data *data, u32 val)
		{
		struct regmap *regmap = data->regmap;
		long rshunt_reg;

		/* RSHUNT register LSB is 10uOhm so need to divide further */
		rshunt_reg = DIV_ROUND_CLOSEST(val, TSC1641_RSHUNT_LSB_UOHM);
		/*
		* Clamp value to the nearest multiple of TSC1641_RSHUNT_LSB_UOHM
		* in case shunt value provided was not a multiple
		*/
		data->rshunt_uohm = rshunt_reg * TSC1641_RSHUNT_LSB_UOHM;
		data->current_lsb_ua = DIV_ROUND_CLOSEST(TSC1641_VSHUNT_LSB_NVOLT * 1000,
		data->rshunt_uohm);

		return regmap_write(regmap, TSC1641_RSHUNT, rshunt_reg);
		}

		/*
		* Conversion times in uS, value in CONFIG[CT3:CT0] corresponds to index in this array
		* See "Table 14. CT3 to CT0: conversion time" in:
		* https://www.st.com/resource/en/datasheet/tsc1641.pdf
		*/
		static const int tsc1641_conv_times[] = { 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768 };

		static int tsc1641_reg_to_upd_interval(u16 config)
		{
		int idx = FIELD_GET(TSC1641_CONV_TIME_MASK, config);

		idx = clamp_val(idx, 0, ARRAY_SIZE(tsc1641_conv_times) - 1);
		int conv_time = tsc1641_conv_times[idx];

		/* Don't support sub-millisecond update interval as it's not supported in hwmon */
		conv_time = max(conv_time, TSC1641_MIN_UPDATE_INTERVAL);
		/* Return nearest value in milliseconds */
		return DIV_ROUND_CLOSEST(conv_time, 1000);
		}

		static u16 tsc1641_upd_interval_to_reg(long interval)
		{
		/* Supported interval is 1ms - 33ms */
		interval = clamp_val(interval, 1, 33);

		int conv = interval * 1000;
		int conv_bits = find_closest(conv, tsc1641_conv_times,
		ARRAY_SIZE(tsc1641_conv_times));

		return FIELD_PREP(TSC1641_CONV_TIME_MASK, conv_bits);
		}

		static int tsc1641_chip_write(struct device *dev, u32 attr, long val)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);

		switch (attr) {
		case hwmon_chip_update_interval:
		return regmap_update_bits(data->regmap, TSC1641_CONFIG,
		TSC1641_CONV_TIME_MASK,
		tsc1641_upd_interval_to_reg(val));
		default:
		return -EOPNOTSUPP;
		}
		}

		static int tsc1641_chip_read(struct device dev, u32 attr, long val)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);
		u32 regval;
		int ret;

		switch (attr) {
		case hwmon_chip_update_interval:
		ret = regmap_read(data->regmap, TSC1641_CONFIG, &regval);
		if (ret)
		return ret;

		*val = tsc1641_reg_to_upd_interval(regval);
		return 0;
		default:
		return -EOPNOTSUPP;
		}
		}

		static int tsc1641_flag_read(struct regmap regmap, u32 flag, long val)
		{
		unsigned int regval;
		int ret;

		ret = regmap_read_bypassed(regmap, TSC1641_FLAG, &regval);
		if (ret)
		return ret;

		*val = !!(regval & flag);
		return 0;
		}

		static int tsc1641_in_read(struct device dev, u32 attr, long val)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);
		struct regmap *regmap = data->regmap;
		unsigned int regval;
		int ret, reg;
		long sat_flag;

		switch (attr) {
		case hwmon_in_input:
		reg = TSC1641_LOAD_VOLTAGE;
		break;
		case hwmon_in_min:
		reg = TSC1641_LUL;
		break;
		case hwmon_in_max:
		reg = TSC1641_LOL;
		break;
		case hwmon_in_min_alarm:
		return tsc1641_flag_read(regmap, TSC1641_LOAD_UV_FLAG, val);
		case hwmon_in_max_alarm:
		return tsc1641_flag_read(regmap, TSC1641_LOAD_OV_FLAG, val);
		default:
		return -EOPNOTSUPP;
		}

		ret = regmap_read(regmap, reg, &regval);
		if (ret)
		return ret;

		/* Check if load voltage is out of range */
		if (reg == TSC1641_LOAD_VOLTAGE) {
		/* Register is 15-bit max */
		if (regval & 0x8000)
		return -ENODATA;

		ret = tsc1641_flag_read(regmap, TSC1641_SAT_FLAG, &sat_flag);
		if (ret)
		return ret;
		/* Out of range conditions per datasheet */
		if (sat_flag && (regval == 0x7FFF \|\| !regval))
		return -ENODATA;
		}

		val = regval TSC1641_VLOAD_LSB_MVOLT;
		return 0;
		}

		/* Chip supports bidirectional (positive or negative) current */
		static int tsc1641_curr_read(struct device dev, u32 attr, long val)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);
		struct regmap *regmap = data->regmap;
		int regval;
		int ret, reg;
		long sat_flag;

		/* Current limits are the shunt under/over voltage limits */
		switch (attr) {
		case hwmon_curr_input:
		reg = TSC1641_CURRENT;
		break;
		case hwmon_curr_min:
		reg = TSC1641_SUL;
		break;
		case hwmon_curr_max:
		reg = TSC1641_SOL;
		break;
		case hwmon_curr_min_alarm:
		return tsc1641_flag_read(regmap, TSC1641_SHUNT_UV_FLAG, val);
		case hwmon_curr_max_alarm:
		return tsc1641_flag_read(regmap, TSC1641_SHUNT_OV_FLAG, val);
		default:
		return -EOPNOTSUPP;
		}
		/*
		* Current uses shunt voltage, so check if it's out of range.
		* We report current register in sysfs to stay consistent with internal
		* power calculations which use current register values
		*/
		if (reg == TSC1641_CURRENT) {
		ret = regmap_read(regmap, TSC1641_SHUNT_VOLTAGE, &regval);
		if (ret)
		return ret;

		ret = tsc1641_flag_read(regmap, TSC1641_SAT_FLAG, &sat_flag);
		if (ret)
		return ret;

		if (sat_flag && (regval == 0x7FFF \|\| regval == 0x8000))
		return -ENODATA;
		}

		ret = regmap_read(regmap, reg, &regval);
		if (ret)
		return ret;

		/* Current in milliamps, signed */
		val = DIV_ROUND_CLOSEST((s16)regval data->current_lsb_ua, 1000);
		return 0;
		}

		static int tsc1641_power_read(struct device dev, u32 attr, long val)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);
		struct regmap *regmap = data->regmap;
		unsigned int regval;
		int ret, reg;

		switch (attr) {
		case hwmon_power_input:
		reg = TSC1641_POWER;
		break;
		case hwmon_power_max:
		reg = TSC1641_POL;
		break;
		case hwmon_power_max_alarm:
		return tsc1641_flag_read(regmap, TSC1641_POWER_OVER_FLAG, val);
		default:
		return -EOPNOTSUPP;
		}

		ret = regmap_read(regmap, reg, &regval);
		if (ret)
		return ret;

		val = regval TSC1641_POWER_LSB_UWATT;
		return 0;
		}

		static int tsc1641_temp_read(struct device dev, u32 attr, long val)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);
		struct regmap *regmap = data->regmap;
		unsigned int regval;
		int ret, reg;

		switch (attr) {
		case hwmon_temp_input:
		reg = TSC1641_TEMP;
		break;
		case hwmon_temp_max:
		reg = TSC1641_TOL;
		break;
		case hwmon_temp_max_alarm:
		return tsc1641_flag_read(regmap, TSC1641_TEMP_OVER_FLAG, val);
		default:
		return -EOPNOTSUPP;
		}

		ret = regmap_read(regmap, reg, &regval);
		if (ret)
		return ret;

		/* 0x8000 means that TEMP measurement not enabled */
		if (reg == TSC1641_TEMP && regval == 0x8000)
		return -ENODATA;

		/* Both temperature and limit registers are signed */
		val = (s16)regval TSC1641_TEMP_LSB_MDEGC;
		return 0;
		}

		static int tsc1641_in_write(struct device *dev, u32 attr, long val)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);
		struct regmap *regmap = data->regmap;
		unsigned int regval;
		int reg;

		switch (attr) {
		case hwmon_in_min:
		reg = TSC1641_LUL;
		break;
		case hwmon_in_max:
		reg = TSC1641_LOL;
		break;
		default:
		return -EOPNOTSUPP;
		}
		/* Clamp to full register range */
		val = clamp_val(val, 0, TSC1641_VLOAD_LSB_MVOLT * USHRT_MAX);
		regval = DIV_ROUND_CLOSEST(val, TSC1641_VLOAD_LSB_MVOLT);

		return regmap_write(regmap, reg, regval);
		}

		static int tsc1641_curr_write(struct device *dev, u32 attr, long val)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);
		struct regmap *regmap = data->regmap;
		int reg, regval;

		switch (attr) {
		case hwmon_curr_min:
		reg = TSC1641_SUL;
		break;
		case hwmon_curr_max:
		reg = TSC1641_SOL;
		break;
		default:
		return -EOPNOTSUPP;
		}

		/* Clamp to prevent over/underflow below */
		val = clamp_val(val, -TSC1641_CURR_ABS_MAX_MAMP, TSC1641_CURR_ABS_MAX_MAMP);
		/* Convert val in milliamps to register */
		regval = DIV_ROUND_CLOSEST(val * 1000, data->current_lsb_ua);
		/*
		* Prevent signed 16-bit overflow.
		* Integer arithmetic and shunt scaling can quantize values near 0x7FFF/0x8000,
		* so reading and writing back may not preserve the exact original register value.
		*/
		regval = clamp_val(regval, SHRT_MIN, SHRT_MAX);
		/* SUL and SOL registers are signed */
		return regmap_write(regmap, reg, regval & 0xFFFF);
		}

		static int tsc1641_power_write(struct device *dev, u32 attr, long val)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);
		struct regmap *regmap = data->regmap;
		unsigned int regval;

		switch (attr) {
		case hwmon_power_max:
		/* Clamp to full register range */
		val = clamp_val(val, 0, TSC1641_POWER_LSB_UWATT * USHRT_MAX);
		regval = DIV_ROUND_CLOSEST(val, TSC1641_POWER_LSB_UWATT);
		return regmap_write(regmap, TSC1641_POL, regval);
		default:
		return -EOPNOTSUPP;
		}
		}

		static int tsc1641_temp_write(struct device *dev, u32 attr, long val)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);
		struct regmap *regmap = data->regmap;
		int regval;

		switch (attr) {
		case hwmon_temp_max:
		/* Clamp to full register range */
		val = clamp_val(val, TSC1641_TEMP_LSB_MDEGC * SHRT_MIN,
		TSC1641_TEMP_LSB_MDEGC * SHRT_MAX);
		regval = DIV_ROUND_CLOSEST(val, TSC1641_TEMP_LSB_MDEGC);
		/* TOL register is signed */
		return regmap_write(regmap, TSC1641_TOL, regval & 0xFFFF);
		default:
		return -EOPNOTSUPP;
		}
		}

		static umode_t tsc1641_is_visible(const void *data, enum hwmon_sensor_types type,
		u32 attr, int channel)
		{
		switch (type) {
		case hwmon_chip:
		switch (attr) {
		case hwmon_chip_update_interval:
		return 0644;
		default:
		break;
		}
		break;
		case hwmon_in:
		switch (attr) {
		case hwmon_in_input:
		return 0444;
		case hwmon_in_min:
		case hwmon_in_max:
		return 0644;
		case hwmon_in_min_alarm:
		case hwmon_in_max_alarm:
		return 0444;
		default:
		break;
		}
		break;
		case hwmon_curr:
		switch (attr) {
		case hwmon_curr_input:
		return 0444;
		case hwmon_curr_min:
		case hwmon_curr_max:
		return 0644;
		case hwmon_curr_min_alarm:
		case hwmon_curr_max_alarm:
		return 0444;
		default:
		break;
		}
		break;
		case hwmon_power:
		switch (attr) {
		case hwmon_power_input:
		return 0444;
		case hwmon_power_max:
		return 0644;
		case hwmon_power_max_alarm:
		return 0444;
		default:
		break;
		}
		break;
		case hwmon_temp:
		switch (attr) {
		case hwmon_temp_input:
		return 0444;
		case hwmon_temp_max:
		return 0644;
		case hwmon_temp_max_alarm:
		return 0444;
		default:
		break;
		}
		break;
		default:
		break;
		}
		return 0;
		}

		static int tsc1641_read(struct device *dev, enum hwmon_sensor_types type,
		u32 attr, int channel, long *val)
		{
		switch (type) {
		case hwmon_chip:
		return tsc1641_chip_read(dev, attr, val);
		case hwmon_in:
		return tsc1641_in_read(dev, attr, val);
		case hwmon_curr:
		return tsc1641_curr_read(dev, attr, val);
		case hwmon_power:
		return tsc1641_power_read(dev, attr, val);
		case hwmon_temp:
		return tsc1641_temp_read(dev, attr, val);
		default:
		return -EOPNOTSUPP;
		}
		}

		static int tsc1641_write(struct device *dev, enum hwmon_sensor_types type,
		u32 attr, int channel, long val)
		{
		switch (type) {
		case hwmon_chip:
		return tsc1641_chip_write(dev, attr, val);
		case hwmon_in:
		return tsc1641_in_write(dev, attr, val);
		case hwmon_curr:
		return tsc1641_curr_write(dev, attr, val);
		case hwmon_power:
		return tsc1641_power_write(dev, attr, val);
		case hwmon_temp:
		return tsc1641_temp_write(dev, attr, val);
		default:
		return -EOPNOTSUPP;
		}
		}

		static const struct hwmon_channel_info * const tsc1641_info[] = {
		HWMON_CHANNEL_INFO(chip,
		HWMON_C_UPDATE_INTERVAL),
		HWMON_CHANNEL_INFO(in,
		HWMON_I_INPUT \| HWMON_I_MAX \| HWMON_I_MAX_ALARM \|
		HWMON_I_MIN \| HWMON_I_MIN_ALARM),
		HWMON_CHANNEL_INFO(curr,
		HWMON_C_INPUT \| HWMON_C_MAX \| HWMON_C_MAX_ALARM \|
		HWMON_C_MIN \| HWMON_C_MIN_ALARM),
		HWMON_CHANNEL_INFO(power,
		HWMON_P_INPUT \| HWMON_P_MAX \| HWMON_P_MAX_ALARM),
		HWMON_CHANNEL_INFO(temp,
		HWMON_T_INPUT \| HWMON_T_MAX \| HWMON_T_MAX_ALARM),
		NULL
		};

		static ssize_t shunt_resistor_show(struct device *dev,
		struct device_attribute da, char buf)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);

		return sysfs_emit(buf, "%li\n", data->rshunt_uohm);
		}

		static ssize_t shunt_resistor_store(struct device *dev,
		struct device_attribute *da,
		const char *buf, size_t count)
		{
		struct tsc1641_data *data = dev_get_drvdata(dev);
		unsigned int val;
		int ret;

		ret = kstrtouint(buf, 10, &val);
		if (ret < 0)
		return ret;

		ret = tsc1641_validate_shunt(val);
		if (ret < 0)
		return ret;

		ret = tsc1641_set_shunt(data, val);
		if (ret < 0)
		return ret;
		return count;
		}

		static const struct hwmon_ops tsc1641_hwmon_ops = {
		.is_visible = tsc1641_is_visible,
		.read = tsc1641_read,
		.write = tsc1641_write,
		};

		static const struct hwmon_chip_info tsc1641_chip_info = {
		.ops = &tsc1641_hwmon_ops,
		.info = tsc1641_info,
		};

		static DEVICE_ATTR_RW(shunt_resistor);

		/* Shunt resistor value is exposed via sysfs attribute */
		static struct attribute *tsc1641_attrs[] = {
		&dev_attr_shunt_resistor.attr,
		NULL,
		};
		ATTRIBUTE_GROUPS(tsc1641);

		static int tsc1641_init(struct device dev, struct tsc1641_data data)
		{
		struct regmap *regmap = data->regmap;
		bool active_high;
		u32 shunt;
		int ret;

		if (device_property_read_u32(dev, "shunt-resistor-micro-ohms", &shunt) < 0)
		shunt = TSC1641_RSHUNT_DEFAULT;

		if (tsc1641_validate_shunt(shunt) < 0) {
		dev_err(dev, "invalid shunt resistor value %u\n", shunt);
		return -EINVAL;
		}

		ret = tsc1641_set_shunt(data, shunt);
		if (ret < 0)
		return ret;

		ret = regmap_write(regmap, TSC1641_CONFIG, TSC1641_CONFIG_DEFAULT);
		if (ret < 0)
		return ret;

		active_high = device_property_read_bool(dev, "st,alert-polarity-active-high");

		return regmap_write(regmap, TSC1641_MASK, TSC1641_MASK_DEFAULT \|
		FIELD_PREP(TSC1641_ALERT_POL_MASK, active_high));
		}

		static int tsc1641_probe(struct i2c_client *client)
		{
		struct device *dev = &client->dev;
		struct tsc1641_data *data;
		struct device *hwmon_dev;
		int ret;

		data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
		if (!data)
		return -ENOMEM;

		data->regmap = devm_regmap_init_i2c(client, &tsc1641_regmap_config);
		if (IS_ERR(data->regmap))
		return dev_err_probe(dev, PTR_ERR(data->regmap),
		"failed to allocate register map\n");

		ret = tsc1641_init(dev, data);
		if (ret < 0)
		return dev_err_probe(dev, ret, "failed to configure device\n");

		hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
		data, &tsc1641_chip_info, tsc1641_groups);
		if (IS_ERR(hwmon_dev))
		return PTR_ERR(hwmon_dev);

		dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n",
		client->name, data->rshunt_uohm);

		return 0;
		}

		static const struct i2c_device_id tsc1641_id[] = {
		{ "tsc1641", 0 },
		{ }
		};
		MODULE_DEVICE_TABLE(i2c, tsc1641_id);

		static const struct of_device_id __maybe_unused tsc1641_of_match[] = {
		{ .compatible = "st,tsc1641" },
		{ },
		};
		MODULE_DEVICE_TABLE(of, tsc1641_of_match);

		static struct i2c_driver tsc1641_driver = {
		.driver = {
		.name = "tsc1641",
		.of_match_table = of_match_ptr(tsc1641_of_match),
		},
		.probe = tsc1641_probe,
		.id_table = tsc1641_id,
		};

		module_i2c_driver(tsc1641_driver);

		MODULE_AUTHOR("Igor Reznichenko <igor@reznichenko.net>");
		MODULE_DESCRIPTION("tsc1641 driver");
		MODULE_LICENSE("GPL");