Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1026 insertions, 0 deletions

diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
new file mode 100644
index 000000000..f3a4c5633
--- /dev/null
+++ b/drivers/hwmon/ina3221.c
@@ -0,0 +1,1026 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * INA3221 Triple Current/Voltage Monitor
+ *
+ * Copyright (C) 2016 Texas Instruments Incorporated - https://www.ti.com/
+ *	Andrew F. Davis <afd@ti.com>
+ */
+
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/util_macros.h>
+
+#define INA3221_DRIVER_NAME		"ina3221"
+
+#define INA3221_CONFIG			0x00
+#define INA3221_SHUNT1			0x01
+#define INA3221_BUS1			0x02
+#define INA3221_SHUNT2			0x03
+#define INA3221_BUS2			0x04
+#define INA3221_SHUNT3			0x05
+#define INA3221_BUS3			0x06
+#define INA3221_CRIT1			0x07
+#define INA3221_WARN1			0x08
+#define INA3221_CRIT2			0x09
+#define INA3221_WARN2			0x0a
+#define INA3221_CRIT3			0x0b
+#define INA3221_WARN3			0x0c
+#define INA3221_SHUNT_SUM		0x0d
+#define INA3221_CRIT_SUM		0x0e
+#define INA3221_MASK_ENABLE		0x0f
+
+#define INA3221_CONFIG_MODE_MASK	GENMASK(2, 0)
+#define INA3221_CONFIG_MODE_POWERDOWN	0
+#define INA3221_CONFIG_MODE_SHUNT	BIT(0)
+#define INA3221_CONFIG_MODE_BUS		BIT(1)
+#define INA3221_CONFIG_MODE_CONTINUOUS	BIT(2)
+#define INA3221_CONFIG_VSH_CT_SHIFT	3
+#define INA3221_CONFIG_VSH_CT_MASK	GENMASK(5, 3)
+#define INA3221_CONFIG_VSH_CT(x)	(((x) & GENMASK(5, 3)) >> 3)
+#define INA3221_CONFIG_VBUS_CT_SHIFT	6
+#define INA3221_CONFIG_VBUS_CT_MASK	GENMASK(8, 6)
+#define INA3221_CONFIG_VBUS_CT(x)	(((x) & GENMASK(8, 6)) >> 6)
+#define INA3221_CONFIG_AVG_SHIFT	9
+#define INA3221_CONFIG_AVG_MASK		GENMASK(11, 9)
+#define INA3221_CONFIG_AVG(x)		(((x) & GENMASK(11, 9)) >> 9)
+#define INA3221_CONFIG_CHs_EN_MASK	GENMASK(14, 12)
+#define INA3221_CONFIG_CHx_EN(x)	BIT(14 - (x))
+
+#define INA3221_MASK_ENABLE_SCC_MASK	GENMASK(14, 12)
+
+#define INA3221_CONFIG_DEFAULT		0x7127
+#define INA3221_RSHUNT_DEFAULT		10000
+
+enum ina3221_fields {
+	/* Configuration */
+	F_RST,
+
+	/* Status Flags */
+	F_CVRF,
+
+	/* Warning Flags */
+	F_WF3, F_WF2, F_WF1,
+
+	/* Alert Flags: SF is the summation-alert flag */
+	F_SF, F_CF3, F_CF2, F_CF1,
+
+	/* sentinel */
+	F_MAX_FIELDS
+};
+
+static const struct reg_field ina3221_reg_fields[] = {
+	[F_RST] = REG_FIELD(INA3221_CONFIG, 15, 15),
+
+	[F_CVRF] = REG_FIELD(INA3221_MASK_ENABLE, 0, 0),
+	[F_WF3] = REG_FIELD(INA3221_MASK_ENABLE, 3, 3),
+	[F_WF2] = REG_FIELD(INA3221_MASK_ENABLE, 4, 4),
+	[F_WF1] = REG_FIELD(INA3221_MASK_ENABLE, 5, 5),
+	[F_SF] = REG_FIELD(INA3221_MASK_ENABLE, 6, 6),
+	[F_CF3] = REG_FIELD(INA3221_MASK_ENABLE, 7, 7),
+	[F_CF2] = REG_FIELD(INA3221_MASK_ENABLE, 8, 8),
+	[F_CF1] = REG_FIELD(INA3221_MASK_ENABLE, 9, 9),
+};
+
+enum ina3221_channels {
+	INA3221_CHANNEL1,
+	INA3221_CHANNEL2,
+	INA3221_CHANNEL3,
+	INA3221_NUM_CHANNELS
+};
+
+/**
+ * struct ina3221_input - channel input source specific information
+ * @label: label of channel input source
+ * @shunt_resistor: shunt resistor value of channel input source
+ * @disconnected: connection status of channel input source
+ */
+struct ina3221_input {
+	const char *label;
+	int shunt_resistor;
+	bool disconnected;
+};
+
+/**
+ * struct ina3221_data - device specific information
+ * @pm_dev: Device pointer for pm runtime
+ * @regmap: Register map of the device
+ * @fields: Register fields of the device
+ * @inputs: Array of channel input source specific structures
+ * @lock: mutex lock to serialize sysfs attribute accesses
+ * @reg_config: Register value of INA3221_CONFIG
+ * @summation_shunt_resistor: equivalent shunt resistor value for summation
+ * @single_shot: running in single-shot operating mode
+ */
+struct ina3221_data {
+	struct device *pm_dev;
+	struct regmap *regmap;
+	struct regmap_field *fields[F_MAX_FIELDS];
+	struct ina3221_input inputs[INA3221_NUM_CHANNELS];
+	struct mutex lock;
+	u32 reg_config;
+	int summation_shunt_resistor;
+
+	bool single_shot;
+};
+
+static inline bool ina3221_is_enabled(struct ina3221_data *ina, int channel)
+{
+	/* Summation channel checks shunt resistor values */
+	if (channel > INA3221_CHANNEL3)
+		return ina->summation_shunt_resistor != 0;
+
+	return pm_runtime_active(ina->pm_dev) &&
+	       (ina->reg_config & INA3221_CONFIG_CHx_EN(channel));
+}
+
+/*
+ * Helper function to return the resistor value for current summation.
+ *
+ * There is a condition to calculate current summation -- all the shunt
+ * resistor values should be the same, so as to simply fit the formula:
+ *     current summation = shunt voltage summation / shunt resistor
+ *
+ * Returns the equivalent shunt resistor value on success or 0 on failure
+ */
+static inline int ina3221_summation_shunt_resistor(struct ina3221_data *ina)
+{
+	struct ina3221_input *input = ina->inputs;
+	int i, shunt_resistor = 0;
+
+	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
+		if (input[i].disconnected || !input[i].shunt_resistor)
+			continue;
+		if (!shunt_resistor) {
+			/* Found the reference shunt resistor value */
+			shunt_resistor = input[i].shunt_resistor;
+		} else {
+			/* No summation if resistor values are different */
+			if (shunt_resistor != input[i].shunt_resistor)
+				return 0;
+		}
+	}
+
+	return shunt_resistor;
+}
+
+/* Lookup table for Bus and Shunt conversion times in usec */
+static const u16 ina3221_conv_time[] = {
+	140, 204, 332, 588, 1100, 2116, 4156, 8244,
+};
+
+/* Lookup table for number of samples using in averaging mode */
+static const int ina3221_avg_samples[] = {
+	1, 4, 16, 64, 128, 256, 512, 1024,
+};
+
+/* Converting update_interval in msec to conversion time in usec */
+static inline u32 ina3221_interval_ms_to_conv_time(u16 config, int interval)
+{
+	u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);
+	u32 samples_idx = INA3221_CONFIG_AVG(config);
+	u32 samples = ina3221_avg_samples[samples_idx];
+
+	/* Bisect the result to Bus and Shunt conversion times */
+	return DIV_ROUND_CLOSEST(interval * 1000 / 2, channels * samples);
+}
+
+/* Converting CONFIG register value to update_interval in usec */
+static inline u32 ina3221_reg_to_interval_us(u16 config)
+{
+	u32 channels = hweight16(config & INA3221_CONFIG_CHs_EN_MASK);
+	u32 vbus_ct_idx = INA3221_CONFIG_VBUS_CT(config);
+	u32 vsh_ct_idx = INA3221_CONFIG_VSH_CT(config);
+	u32 vbus_ct = ina3221_conv_time[vbus_ct_idx];
+	u32 vsh_ct = ina3221_conv_time[vsh_ct_idx];
+
+	/* Calculate total conversion time */
+	return channels * (vbus_ct + vsh_ct);
+}
+
+static inline int ina3221_wait_for_data(struct ina3221_data *ina)
+{
+	u32 wait, cvrf;
+
+	wait = ina3221_reg_to_interval_us(ina->reg_config);
+
+	/* Polling the CVRF bit to make sure read data is ready */
+	return regmap_field_read_poll_timeout(ina->fields[F_CVRF],
+					      cvrf, cvrf, wait, wait * 2);
+}
+
+static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
+			      int *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(ina->regmap, reg, &regval);
+	if (ret)
+		return ret;
+
+	/*
+	 * Shunt Voltage Sum register has 14-bit value with 1-bit shift
+	 * Other Shunt Voltage registers have 12 bits with 3-bit shift
+	 */
+	if (reg == INA3221_SHUNT_SUM || reg == INA3221_CRIT_SUM)
+		*val = sign_extend32(regval >> 1, 14);
+	else
+		*val = sign_extend32(regval >> 3, 12);
+
+	return 0;
+}
+
+static const u8 ina3221_in_reg[] = {
+	INA3221_BUS1,
+	INA3221_BUS2,
+	INA3221_BUS3,
+	INA3221_SHUNT1,
+	INA3221_SHUNT2,
+	INA3221_SHUNT3,
+	INA3221_SHUNT_SUM,
+};
+
+static int ina3221_read_chip(struct device *dev, u32 attr, long *val)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	int regval;
+
+	switch (attr) {
+	case hwmon_chip_samples:
+		regval = INA3221_CONFIG_AVG(ina->reg_config);
+		*val = ina3221_avg_samples[regval];
+		return 0;
+	case hwmon_chip_update_interval:
+		/* Return in msec */
+		*val = ina3221_reg_to_interval_us(ina->reg_config);
+		*val = DIV_ROUND_CLOSEST(*val, 1000);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ina3221_read_in(struct device *dev, u32 attr, int channel, long *val)
+{
+	const bool is_shunt = channel > INA3221_CHANNEL3;
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	u8 reg = ina3221_in_reg[channel];
+	int regval, ret;
+
+	/*
+	 * Translate shunt channel index to sensor channel index except
+	 * the 7th channel (6 since being 0-aligned) is for summation.
+	 */
+	if (channel != 6)
+		channel %= INA3221_NUM_CHANNELS;
+
+	switch (attr) {
+	case hwmon_in_input:
+		if (!ina3221_is_enabled(ina, channel))
+			return -ENODATA;
+
+		/* Write CONFIG register to trigger a single-shot measurement */
+		if (ina->single_shot) {
+			regmap_write(ina->regmap, INA3221_CONFIG,
+				     ina->reg_config);
+
+			ret = ina3221_wait_for_data(ina);
+			if (ret)
+				return ret;
+		}
+
+		ret = ina3221_read_value(ina, reg, &regval);
+		if (ret)
+			return ret;
+
+		/*
+		 * Scale of shunt voltage (uV): LSB is 40uV
+		 * Scale of bus voltage (mV): LSB is 8mV
+		 */
+		*val = regval * (is_shunt ? 40 : 8);
+		return 0;
+	case hwmon_in_enable:
+		*val = ina3221_is_enabled(ina, channel);
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static const u8 ina3221_curr_reg[][INA3221_NUM_CHANNELS + 1] = {
+	[hwmon_curr_input] = { INA3221_SHUNT1, INA3221_SHUNT2,
+			       INA3221_SHUNT3, INA3221_SHUNT_SUM },
+	[hwmon_curr_max] = { INA3221_WARN1, INA3221_WARN2, INA3221_WARN3, 0 },
+	[hwmon_curr_crit] = { INA3221_CRIT1, INA3221_CRIT2,
+			      INA3221_CRIT3, INA3221_CRIT_SUM },
+	[hwmon_curr_max_alarm] = { F_WF1, F_WF2, F_WF3, 0 },
+	[hwmon_curr_crit_alarm] = { F_CF1, F_CF2, F_CF3, F_SF },
+};
+
+static int ina3221_read_curr(struct device *dev, u32 attr,
+			     int channel, long *val)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	struct ina3221_input *input = ina->inputs;
+	u8 reg = ina3221_curr_reg[attr][channel];
+	int resistance_uo, voltage_nv;
+	int regval, ret;
+
+	if (channel > INA3221_CHANNEL3)
+		resistance_uo = ina->summation_shunt_resistor;
+	else
+		resistance_uo = input[channel].shunt_resistor;
+
+	switch (attr) {
+	case hwmon_curr_input:
+		if (!ina3221_is_enabled(ina, channel))
+			return -ENODATA;
+
+		/* Write CONFIG register to trigger a single-shot measurement */
+		if (ina->single_shot) {
+			regmap_write(ina->regmap, INA3221_CONFIG,
+				     ina->reg_config);
+
+			ret = ina3221_wait_for_data(ina);
+			if (ret)
+				return ret;
+		}
+
+		fallthrough;
+	case hwmon_curr_crit:
+	case hwmon_curr_max:
+		if (!resistance_uo)
+			return -ENODATA;
+
+		ret = ina3221_read_value(ina, reg, &regval);
+		if (ret)
+			return ret;
+
+		/* Scale of shunt voltage: LSB is 40uV (40000nV) */
+		voltage_nv = regval * 40000;
+		/* Return current in mA */
+		*val = DIV_ROUND_CLOSEST(voltage_nv, resistance_uo);
+		return 0;
+	case hwmon_curr_crit_alarm:
+	case hwmon_curr_max_alarm:
+		/* No actual register read if channel is disabled */
+		if (!ina3221_is_enabled(ina, channel)) {
+			/* Return 0 for alert flags */
+			*val = 0;
+			return 0;
+		}
+		ret = regmap_field_read(ina->fields[reg], &regval);
+		if (ret)
+			return ret;
+		*val = regval;
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ina3221_write_chip(struct device *dev, u32 attr, long val)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	int ret, idx;
+	u32 tmp;
+
+	switch (attr) {
+	case hwmon_chip_samples:
+		idx = find_closest(val, ina3221_avg_samples,
+				   ARRAY_SIZE(ina3221_avg_samples));
+
+		tmp = (ina->reg_config & ~INA3221_CONFIG_AVG_MASK) |
+		      (idx << INA3221_CONFIG_AVG_SHIFT);
+		ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
+		if (ret)
+			return ret;
+
+		/* Update reg_config accordingly */
+		ina->reg_config = tmp;
+		return 0;
+	case hwmon_chip_update_interval:
+		tmp = ina3221_interval_ms_to_conv_time(ina->reg_config, val);
+		idx = find_closest(tmp, ina3221_conv_time,
+				   ARRAY_SIZE(ina3221_conv_time));
+
+		/* Update Bus and Shunt voltage conversion times */
+		tmp = INA3221_CONFIG_VBUS_CT_MASK | INA3221_CONFIG_VSH_CT_MASK;
+		tmp = (ina->reg_config & ~tmp) |
+		      (idx << INA3221_CONFIG_VBUS_CT_SHIFT) |
+		      (idx << INA3221_CONFIG_VSH_CT_SHIFT);
+		ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
+		if (ret)
+			return ret;
+
+		/* Update reg_config accordingly */
+		ina->reg_config = tmp;
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int ina3221_write_curr(struct device *dev, u32 attr,
+			      int channel, long val)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	struct ina3221_input *input = ina->inputs;
+	u8 reg = ina3221_curr_reg[attr][channel];
+	int resistance_uo, current_ma, voltage_uv;
+	int regval;
+
+	if (channel > INA3221_CHANNEL3)
+		resistance_uo = ina->summation_shunt_resistor;
+	else
+		resistance_uo = input[channel].shunt_resistor;
+
+	if (!resistance_uo)
+		return -EOPNOTSUPP;
+
+	/* clamp current */
+	current_ma = clamp_val(val,
+			       INT_MIN / resistance_uo,
+			       INT_MAX / resistance_uo);
+
+	voltage_uv = DIV_ROUND_CLOSEST(current_ma * resistance_uo, 1000);
+
+	/* clamp voltage */
+	voltage_uv = clamp_val(voltage_uv, -163800, 163800);
+
+	/*
+	 * Formula to convert voltage_uv to register value:
+	 *     regval = (voltage_uv / scale) << shift
+	 * Note:
+	 *     The scale is 40uV for all shunt voltage registers
+	 *     Shunt Voltage Sum register left-shifts 1 bit
+	 *     All other Shunt Voltage registers shift 3 bits
+	 * Results:
+	 *     SHUNT_SUM: (1 / 40uV) << 1 = 1 / 20uV
+	 *     SHUNT[1-3]: (1 / 40uV) << 3 = 1 / 5uV
+	 */
+	if (reg == INA3221_SHUNT_SUM || reg == INA3221_CRIT_SUM)
+		regval = DIV_ROUND_CLOSEST(voltage_uv, 20) & 0xfffe;
+	else
+		regval = DIV_ROUND_CLOSEST(voltage_uv, 5) & 0xfff8;
+
+	return regmap_write(ina->regmap, reg, regval);
+}
+
+static int ina3221_write_enable(struct device *dev, int channel, bool enable)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	u16 config, mask = INA3221_CONFIG_CHx_EN(channel);
+	u16 config_old = ina->reg_config & mask;
+	u32 tmp;
+	int ret;
+
+	config = enable ? mask : 0;
+
+	/* Bypass if enable status is not being changed */
+	if (config_old == config)
+		return 0;
+
+	/* For enabling routine, increase refcount and resume() at first */
+	if (enable) {
+		ret = pm_runtime_resume_and_get(ina->pm_dev);
+		if (ret < 0) {
+			dev_err(dev, "Failed to get PM runtime\n");
+			return ret;
+		}
+	}
+
+	/* Enable or disable the channel */
+	tmp = (ina->reg_config & ~mask) | (config & mask);
+	ret = regmap_write(ina->regmap, INA3221_CONFIG, tmp);
+	if (ret)
+		goto fail;
+
+	/* Cache the latest config register value */
+	ina->reg_config = tmp;
+
+	/* For disabling routine, decrease refcount or suspend() at last */
+	if (!enable)
+		pm_runtime_put_sync(ina->pm_dev);
+
+	return 0;
+
+fail:
+	if (enable) {
+		dev_err(dev, "Failed to enable channel %d: error %d\n",
+			channel, ret);
+		pm_runtime_put_sync(ina->pm_dev);
+	}
+
+	return ret;
+}
+
+static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	int ret;
+
+	mutex_lock(&ina->lock);
+
+	switch (type) {
+	case hwmon_chip:
+		ret = ina3221_read_chip(dev, attr, val);
+		break;
+	case hwmon_in:
+		/* 0-align channel ID */
+		ret = ina3221_read_in(dev, attr, channel - 1, val);
+		break;
+	case hwmon_curr:
+		ret = ina3221_read_curr(dev, attr, channel, val);
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+
+	mutex_unlock(&ina->lock);
+
+	return ret;
+}
+
+static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long val)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	int ret;
+
+	mutex_lock(&ina->lock);
+
+	switch (type) {
+	case hwmon_chip:
+		ret = ina3221_write_chip(dev, attr, val);
+		break;
+	case hwmon_in:
+		/* 0-align channel ID */
+		ret = ina3221_write_enable(dev, channel - 1, val);
+		break;
+	case hwmon_curr:
+		ret = ina3221_write_curr(dev, attr, channel, val);
+		break;
+	default:
+		ret = -EOPNOTSUPP;
+		break;
+	}
+
+	mutex_unlock(&ina->lock);
+
+	return ret;
+}
+
+static int ina3221_read_string(struct device *dev, enum hwmon_sensor_types type,
+			       u32 attr, int channel, const char **str)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	int index = channel - 1;
+
+	if (channel == 7)
+		*str = "sum of shunt voltages";
+	else
+		*str = ina->inputs[index].label;
+
+	return 0;
+}
+
+static umode_t ina3221_is_visible(const void *drvdata,
+				  enum hwmon_sensor_types type,
+				  u32 attr, int channel)
+{
+	const struct ina3221_data *ina = drvdata;
+	const struct ina3221_input *input = NULL;
+
+	switch (type) {
+	case hwmon_chip:
+		switch (attr) {
+		case hwmon_chip_samples:
+		case hwmon_chip_update_interval:
+			return 0644;
+		default:
+			return 0;
+		}
+	case hwmon_in:
+		/* Ignore in0_ */
+		if (channel == 0)
+			return 0;
+
+		switch (attr) {
+		case hwmon_in_label:
+			if (channel - 1 <= INA3221_CHANNEL3)
+				input = &ina->inputs[channel - 1];
+			else if (channel == 7)
+				return 0444;
+			/* Hide label node if label is not provided */
+			return (input && input->label) ? 0444 : 0;
+		case hwmon_in_input:
+			return 0444;
+		case hwmon_in_enable:
+			return 0644;
+		default:
+			return 0;
+		}
+	case hwmon_curr:
+		switch (attr) {
+		case hwmon_curr_input:
+		case hwmon_curr_crit_alarm:
+		case hwmon_curr_max_alarm:
+			return 0444;
+		case hwmon_curr_crit:
+		case hwmon_curr_max:
+			return 0644;
+		default:
+			return 0;
+		}
+	default:
+		return 0;
+	}
+}
+
+#define INA3221_HWMON_CURR_CONFIG (HWMON_C_INPUT | \
+				   HWMON_C_CRIT | HWMON_C_CRIT_ALARM | \
+				   HWMON_C_MAX | HWMON_C_MAX_ALARM)
+
+static const struct hwmon_channel_info *ina3221_info[] = {
+	HWMON_CHANNEL_INFO(chip,
+			   HWMON_C_SAMPLES,
+			   HWMON_C_UPDATE_INTERVAL),
+	HWMON_CHANNEL_INFO(in,
+			   /* 0: dummy, skipped in is_visible */
+			   HWMON_I_INPUT,
+			   /* 1-3: input voltage Channels */
+			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
+			   HWMON_I_INPUT | HWMON_I_ENABLE | HWMON_I_LABEL,
+			   /* 4-6: shunt voltage Channels */
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   HWMON_I_INPUT,
+			   /* 7: summation of shunt voltage channels */
+			   HWMON_I_INPUT | HWMON_I_LABEL),
+	HWMON_CHANNEL_INFO(curr,
+			   /* 1-3: current channels*/
+			   INA3221_HWMON_CURR_CONFIG,
+			   INA3221_HWMON_CURR_CONFIG,
+			   INA3221_HWMON_CURR_CONFIG,
+			   /* 4: summation of current channels */
+			   HWMON_C_INPUT | HWMON_C_CRIT | HWMON_C_CRIT_ALARM),
+	NULL
+};
+
+static const struct hwmon_ops ina3221_hwmon_ops = {
+	.is_visible = ina3221_is_visible,
+	.read_string = ina3221_read_string,
+	.read = ina3221_read,
+	.write = ina3221_write,
+};
+
+static const struct hwmon_chip_info ina3221_chip_info = {
+	.ops = &ina3221_hwmon_ops,
+	.info = ina3221_info,
+};
+
+/* Extra attribute groups */
+static ssize_t ina3221_shunt_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
+{
+	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	unsigned int channel = sd_attr->index;
+	struct ina3221_input *input = &ina->inputs[channel];
+
+	return sysfs_emit(buf, "%d\n", input->shunt_resistor);
+}
+
+static ssize_t ina3221_shunt_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(attr);
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	unsigned int channel = sd_attr->index;
+	struct ina3221_input *input = &ina->inputs[channel];
+	int val;
+	int ret;
+
+	ret = kstrtoint(buf, 0, &val);
+	if (ret)
+		return ret;
+
+	val = clamp_val(val, 1, INT_MAX);
+
+	input->shunt_resistor = val;
+
+	/* Update summation_shunt_resistor for summation channel */
+	ina->summation_shunt_resistor = ina3221_summation_shunt_resistor(ina);
+
+	return count;
+}
+
+/* shunt resistance */
+static SENSOR_DEVICE_ATTR_RW(shunt1_resistor, ina3221_shunt, INA3221_CHANNEL1);
+static SENSOR_DEVICE_ATTR_RW(shunt2_resistor, ina3221_shunt, INA3221_CHANNEL2);
+static SENSOR_DEVICE_ATTR_RW(shunt3_resistor, ina3221_shunt, INA3221_CHANNEL3);
+
+static struct attribute *ina3221_attrs[] = {
+	&sensor_dev_attr_shunt1_resistor.dev_attr.attr,
+	&sensor_dev_attr_shunt2_resistor.dev_attr.attr,
+	&sensor_dev_attr_shunt3_resistor.dev_attr.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(ina3221);
+
+static const struct regmap_range ina3221_yes_ranges[] = {
+	regmap_reg_range(INA3221_CONFIG, INA3221_BUS3),
+	regmap_reg_range(INA3221_SHUNT_SUM, INA3221_SHUNT_SUM),
+	regmap_reg_range(INA3221_MASK_ENABLE, INA3221_MASK_ENABLE),
+};
+
+static const struct regmap_access_table ina3221_volatile_table = {
+	.yes_ranges = ina3221_yes_ranges,
+	.n_yes_ranges = ARRAY_SIZE(ina3221_yes_ranges),
+};
+
+static const struct regmap_config ina3221_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+
+	.cache_type = REGCACHE_RBTREE,
+	.volatile_table = &ina3221_volatile_table,
+};
+
+static int ina3221_probe_child_from_dt(struct device *dev,
+				       struct device_node *child,
+				       struct ina3221_data *ina)
+{
+	struct ina3221_input *input;
+	u32 val;
+	int ret;
+
+	ret = of_property_read_u32(child, "reg", &val);
+	if (ret) {
+		dev_err(dev, "missing reg property of %pOFn\n", child);
+		return ret;
+	} else if (val > INA3221_CHANNEL3) {
+		dev_err(dev, "invalid reg %d of %pOFn\n", val, child);
+		return -EINVAL;
+	}
+
+	input = &ina->inputs[val];
+
+	/* Log the disconnected channel input */
+	if (!of_device_is_available(child)) {
+		input->disconnected = true;
+		return 0;
+	}
+
+	/* Save the connected input label if available */
+	of_property_read_string(child, "label", &input->label);
+
+	/* Overwrite default shunt resistor value optionally */
+	if (!of_property_read_u32(child, "shunt-resistor-micro-ohms", &val)) {
+		if (val < 1 || val > INT_MAX) {
+			dev_err(dev, "invalid shunt resistor value %u of %pOFn\n",
+				val, child);
+			return -EINVAL;
+		}
+		input->shunt_resistor = val;
+	}
+
+	return 0;
+}
+
+static int ina3221_probe_from_dt(struct device *dev, struct ina3221_data *ina)
+{
+	const struct device_node *np = dev->of_node;
+	struct device_node *child;
+	int ret;
+
+	/* Compatible with non-DT platforms */
+	if (!np)
+		return 0;
+
+	ina->single_shot = of_property_read_bool(np, "ti,single-shot");
+
+	for_each_child_of_node(np, child) {
+		ret = ina3221_probe_child_from_dt(dev, child, ina);
+		if (ret) {
+			of_node_put(child);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int ina3221_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct ina3221_data *ina;
+	struct device *hwmon_dev;
+	int i, ret;
+
+	ina = devm_kzalloc(dev, sizeof(*ina), GFP_KERNEL);
+	if (!ina)
+		return -ENOMEM;
+
+	ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
+	if (IS_ERR(ina->regmap)) {
+		dev_err(dev, "Unable to allocate register map\n");
+		return PTR_ERR(ina->regmap);
+	}
+
+	for (i = 0; i < F_MAX_FIELDS; i++) {
+		ina->fields[i] = devm_regmap_field_alloc(dev,
+							 ina->regmap,
+							 ina3221_reg_fields[i]);
+		if (IS_ERR(ina->fields[i])) {
+			dev_err(dev, "Unable to allocate regmap fields\n");
+			return PTR_ERR(ina->fields[i]);
+		}
+	}
+
+	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
+		ina->inputs[i].shunt_resistor = INA3221_RSHUNT_DEFAULT;
+
+	ret = ina3221_probe_from_dt(dev, ina);
+	if (ret) {
+		dev_err(dev, "Unable to probe from device tree\n");
+		return ret;
+	}
+
+	/* The driver will be reset, so use reset value */
+	ina->reg_config = INA3221_CONFIG_DEFAULT;
+
+	/* Clear continuous bit to use single-shot mode */
+	if (ina->single_shot)
+		ina->reg_config &= ~INA3221_CONFIG_MODE_CONTINUOUS;
+
+	/* Disable channels if their inputs are disconnected */
+	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
+		if (ina->inputs[i].disconnected)
+			ina->reg_config &= ~INA3221_CONFIG_CHx_EN(i);
+	}
+
+	/* Initialize summation_shunt_resistor for summation channel control */
+	ina->summation_shunt_resistor = ina3221_summation_shunt_resistor(ina);
+
+	ina->pm_dev = dev;
+	mutex_init(&ina->lock);
+	dev_set_drvdata(dev, ina);
+
+	/* Enable PM runtime -- status is suspended by default */
+	pm_runtime_enable(ina->pm_dev);
+
+	/* Initialize (resume) the device */
+	for (i = 0; i < INA3221_NUM_CHANNELS; i++) {
+		if (ina->inputs[i].disconnected)
+			continue;
+		/* Match the refcount with number of enabled channels */
+		ret = pm_runtime_get_sync(ina->pm_dev);
+		if (ret < 0)
+			goto fail;
+	}
+
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, ina,
+							 &ina3221_chip_info,
+							 ina3221_groups);
+	if (IS_ERR(hwmon_dev)) {
+		dev_err(dev, "Unable to register hwmon device\n");
+		ret = PTR_ERR(hwmon_dev);
+		goto fail;
+	}
+
+	return 0;
+
+fail:
+	pm_runtime_disable(ina->pm_dev);
+	pm_runtime_set_suspended(ina->pm_dev);
+	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
+	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
+		pm_runtime_put_noidle(ina->pm_dev);
+	mutex_destroy(&ina->lock);
+
+	return ret;
+}
+
+static void ina3221_remove(struct i2c_client *client)
+{
+	struct ina3221_data *ina = dev_get_drvdata(&client->dev);
+	int i;
+
+	pm_runtime_disable(ina->pm_dev);
+	pm_runtime_set_suspended(ina->pm_dev);
+
+	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
+	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
+		pm_runtime_put_noidle(ina->pm_dev);
+
+	mutex_destroy(&ina->lock);
+}
+
+static int ina3221_suspend(struct device *dev)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	int ret;
+
+	/* Save config register value and enable cache-only */
+	ret = regmap_read(ina->regmap, INA3221_CONFIG, &ina->reg_config);
+	if (ret)
+		return ret;
+
+	/* Set to power-down mode for power saving */
+	ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
+				 INA3221_CONFIG_MODE_MASK,
+				 INA3221_CONFIG_MODE_POWERDOWN);
+	if (ret)
+		return ret;
+
+	regcache_cache_only(ina->regmap, true);
+	regcache_mark_dirty(ina->regmap);
+
+	return 0;
+}
+
+static int ina3221_resume(struct device *dev)
+{
+	struct ina3221_data *ina = dev_get_drvdata(dev);
+	int ret;
+
+	regcache_cache_only(ina->regmap, false);
+
+	/* Software reset the chip */
+	ret = regmap_field_write(ina->fields[F_RST], true);
+	if (ret) {
+		dev_err(dev, "Unable to reset device\n");
+		return ret;
+	}
+
+	/* Restore cached register values to hardware */
+	ret = regcache_sync(ina->regmap);
+	if (ret)
+		return ret;
+
+	/* Restore config register value to hardware */
+	ret = regmap_write(ina->regmap, INA3221_CONFIG, ina->reg_config);
+	if (ret)
+		return ret;
+
+	/* Initialize summation channel control */
+	if (ina->summation_shunt_resistor) {
+		/*
+		 * Take all three channels into summation by default
+		 * Shunt measurements of disconnected channels should
+		 * be 0, so it does not matter for summation.
+		 */
+		ret = regmap_update_bits(ina->regmap, INA3221_MASK_ENABLE,
+					 INA3221_MASK_ENABLE_SCC_MASK,
+					 INA3221_MASK_ENABLE_SCC_MASK);
+		if (ret) {
+			dev_err(dev, "Unable to control summation channel\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(ina3221_pm, ina3221_suspend, ina3221_resume,
+				 NULL);
+
+static const struct of_device_id ina3221_of_match_table[] = {
+	{ .compatible = "ti,ina3221", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, ina3221_of_match_table);
+
+static const struct i2c_device_id ina3221_ids[] = {
+	{ "ina3221", 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, ina3221_ids);
+
+static struct i2c_driver ina3221_i2c_driver = {
+	.probe_new = ina3221_probe,
+	.remove = ina3221_remove,
+	.driver = {
+		.name = INA3221_DRIVER_NAME,
+		.of_match_table = ina3221_of_match_table,
+		.pm = pm_ptr(&ina3221_pm),
+	},
+	.id_table = ina3221_ids,
+};
+module_i2c_driver(ina3221_i2c_driver);
+
+MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
+MODULE_DESCRIPTION("Texas Instruments INA3221 HWMon Driver");
+MODULE_LICENSE("GPL v2");