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[1/1] hwmon: Add support for INA3221 Triple Current/Voltage Monitors

Message ID 1460407827-29177-1-git-send-email-afd@ti.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Andrew F. Davis April 11, 2016, 8:50 p.m. UTC
Add support for the the INA3221 26v capable, Triple channel,
Bi-Directional, Zero-Drift, Low-/High-Side, Current/Voltage Monitor
with I2C interface.

Signed-off-by: Andrew F. Davis <afd@ti.com>
---
 Documentation/hwmon/ina3221 |  32 ++++
 drivers/hwmon/Kconfig       |  11 ++
 drivers/hwmon/Makefile      |   1 +
 drivers/hwmon/ina3221.c     | 398 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 442 insertions(+)
 create mode 100644 Documentation/hwmon/ina3221
 create mode 100644 drivers/hwmon/ina3221.c

Comments

Guenter Roeck April 19, 2016, 2:09 p.m. UTC | #1
On 04/11/2016 01:50 PM, Andrew F. Davis wrote:
> Add support for the the INA3221 26v capable, Triple channel,
> Bi-Directional, Zero-Drift, Low-/High-Side, Current/Voltage Monitor
> with I2C interface.
>
> Signed-off-by: Andrew F. Davis <afd@ti.com>
> ---
>   Documentation/hwmon/ina3221 |  32 ++++
>   drivers/hwmon/Kconfig       |  11 ++
>   drivers/hwmon/Makefile      |   1 +
>   drivers/hwmon/ina3221.c     | 398 ++++++++++++++++++++++++++++++++++++++++++++
>   4 files changed, 442 insertions(+)
>   create mode 100644 Documentation/hwmon/ina3221
>   create mode 100644 drivers/hwmon/ina3221.c
>
> diff --git a/Documentation/hwmon/ina3221 b/Documentation/hwmon/ina3221
> new file mode 100644
> index 0000000..3de3814
> --- /dev/null
> +++ b/Documentation/hwmon/ina3221
> @@ -0,0 +1,32 @@
> +Kernel driver ina3221
> +=====================
> +
> +Supported chips:
> +  * Texas Instruments INA3221
> +    Prefix: 'ina3221'
> +    Addresses: I2C 0x40 - 0x43
> +    Datasheet: Publicly available at the Texas Instruments website
> +               http://www.ti.com/
> +
> +Author: Andrew F. Davis <afd@ti.com>
> +
> +Description
> +-----------
> +
> +The Texas Instruments INA3221 monitors voltage, current, and power on the high
> +side of up to three D.C. power supplies. The INA3221 monitors both shunt drop
> +and supply voltage, with programmable conversion times and averaging, current
> +and power are calculated host-side from these.
> +
> +Sysfs entries
> +-------------
> +
> +in[012]_input           Bus voltages(mV) for channels 1, 2, and 3 respectively
> +in[345]_input           Shunt voltages(mV) for channels 1, 2, and 3 respectively
> +curr[012]_input         Current(mA) measurement for channels 1, 2, and 3 respectively

Numbering for currents is [123], not [012].

> +power[012]_input        Power(uW) measurement for channels 1, 2, and 3 respectively

hwmon only reports what is there, and doesn't do calculations. The chip doesn't report
the power, so please drop the power attributes.

> +shunt[012]_resistor     Shunt resistance(uOhm) for channels 1, 2, and 3 respectively

This should be a backup, if neither devicetree nor platform data are provided,
not a primary means to provide the shunt resistor value. Also, there should be a default,
to make sure the driver provides useful data even if nothing is configured.
See ina2xx.c for an example.

> +critical[012]_alarm     Critical alert voltage(mV) setting, activated when the
> +                        respective shunt voltage is above this value.
> +warning[012]_alarm      Warning alert voltage(mV) setting, activated when the
> +                        respective shunt voltage average is above this value.

Alarm attributes report the alarm status, not voltages. Use in[012]_max and
in[012]_crit attributes to set the limits. Report the alarm status with
in[012]_max_alarm and in[012]_crit_alarm (from register 0x0f, bit 9-7 and
5-3).

> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 5c2d13a..de08242 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1503,6 +1503,17 @@ config SENSORS_INA2XX
>   	  This driver can also be built as a module.  If so, the module
>   	  will be called ina2xx.
>
> +config SENSORS_INA3221
> +	tristate "Texas Instruments INA3221 Triple Power Monitor"
> +	depends on I2C
> +	select REGMAP_I2C
> +	help
> +	  If you say yes here you get support for  the TI INA3221 Triple Power
> +	  Monitor.
> +
> +	  This driver can also be built as a module.  If so, the module
> +	  will be called ina3221.
> +
>   config SENSORS_TC74
>   	tristate "Microchip TC74"
>   	depends on I2C
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index 58cc3ac..83e8ab0 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -77,6 +77,7 @@ obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o
>   obj-$(CONFIG_SENSORS_IIO_HWMON) += iio_hwmon.o
>   obj-$(CONFIG_SENSORS_INA209)	+= ina209.o
>   obj-$(CONFIG_SENSORS_INA2XX)	+= ina2xx.o
> +obj-$(CONFIG_SENSORS_INA3221)	+= ina3221.o
>   obj-$(CONFIG_SENSORS_IT87)	+= it87.o
>   obj-$(CONFIG_SENSORS_JC42)	+= jc42.o
>   obj-$(CONFIG_SENSORS_JZ4740)	+= jz4740-hwmon.o
> diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
> new file mode 100644
> index 0000000..763e23b
> --- /dev/null
> +++ b/drivers/hwmon/ina3221.c
> @@ -0,0 +1,398 @@
> +/*
> + * INA3221 Triple Current/Voltage Monitor
> + *
> + * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
> + *	Andrew F. Davis <afd@ti.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +
> +#include <linux/hwmon.h>
> +#include <linux/hwmon-sysfs.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_SHUNT_SUM_LIMIT		0x0e
> +#define INA3221_MASK_ENABLE		0x0f
> +#define INA3221_POWERV_HLIMIT		0x10
> +#define INA3221_POWERV_LLIMIT		0x11
> +
> +#define INA3221_CONFIG_MODE_SHUNT	BIT(1)
> +#define INA3221_CONFIG_MODE_BUS		BIT(2)
> +#define INA3221_CONFIG_MODE_CONTINUOUS	BIT(3)
> +
> +enum ina3221_fields {
> +	/* Configuration */
> +	F_MODE, F_SHUNT_CT, F_BUS_CT, F_AVG,
> +	F_CHAN3_EN, F_CHAN2_EN, F_CHAN1_EN, F_RST,
> +
> +	/* sentinel */
> +	F_MAX_FIELDS
> +};
> +
> +static const struct reg_field ina3221_reg_fields[] = {
> +	[F_MODE]	= REG_FIELD(INA3221_CONFIG, 0, 2),
> +	[F_SHUNT_CT]	= REG_FIELD(INA3221_CONFIG, 3, 5),
> +	[F_BUS_CT]	= REG_FIELD(INA3221_CONFIG, 6, 8),
> +	[F_AVG]		= REG_FIELD(INA3221_CONFIG, 9, 11),
> +	[F_CHAN3_EN]	= REG_FIELD(INA3221_CONFIG, 12, 12),
> +	[F_CHAN2_EN]	= REG_FIELD(INA3221_CONFIG, 13, 13),
> +	[F_CHAN1_EN]	= REG_FIELD(INA3221_CONFIG, 14, 14),
> +	[F_RST]		= REG_FIELD(INA3221_CONFIG, 15, 15),
> +};
> +
> +enum ina3221_channels {
> +	INA3221_CHANNEL1,
> +	INA3221_CHANNEL2,
> +	INA3221_CHANNEL3,
> +	INA3221_NUM_CHANNELS
> +};
> +
> +static const int shunt_registers[] = {
> +	[INA3221_CHANNEL1] = INA3221_SHUNT1,
> +	[INA3221_CHANNEL2] = INA3221_SHUNT2,
> +	[INA3221_CHANNEL3] = INA3221_SHUNT3,
> +};
> +
> +static const int bus_registers[] = {
> +	[INA3221_CHANNEL1] = INA3221_BUS1,
> +	[INA3221_CHANNEL2] = INA3221_BUS2,
> +	[INA3221_CHANNEL3] = INA3221_BUS3,
> +};
> +
> +/**
> + * struct ina3221_data - device specific information
> + * @dev: Device structure
> + * @regmap: Register map of the device
> + * @fields: Register fields of the device
> + */
> +struct ina3221_data {
> +	struct device *dev;
> +	struct regmap *regmap;
> +	struct regmap_field *fields[F_MAX_FIELDS];
> +	unsigned int shunt_resistors[INA3221_NUM_CHANNELS];
> +};
> +
> +static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
> +			      unsigned int *val)
> +{
> +	unsigned int regval;
> +	int ret;
> +
> +	ret = regmap_read(ina->regmap, reg, &regval);
> +	if (ret)
> +		return ret;
> +
> +	*val = sign_extend32(regval >> 3, 12);
> +
> +	return 0;
> +}
> +
> +static ssize_t ina3221_show_voltage(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 reg = sd_attr->index;
> +	int val, voltage_mv, ret;
> +
> +	ret = ina3221_read_value(ina, reg, &val);
> +	if (ret)
> +		return ret;
> +
> +	if (reg == INA3221_BUS1 ||
> +	    reg == INA3221_BUS2 ||
> +	    reg == INA3221_BUS3)
> +		voltage_mv = val * 8;
> +	else
> +		voltage_mv = DIV_ROUND_CLOSEST(val * 40, 1000);
> +
> +	return snprintf(buf, PAGE_SIZE, "%d\n", voltage_mv);
> +}
> +
> +static ssize_t ina3221_set_voltage(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 reg = sd_attr->index;
> +	int val, ret;
> +
> +	ret = kstrtoint(buf, 10, &val);
> +	if (ret)
> +		return ret;
> +
Please clamp the value to valid voltage range.

> +	val = DIV_ROUND_CLOSEST(val, 40000) << 3;
> +
> +	ret = regmap_write(ina->regmap, reg, val);
> +	if (ret)
> +		return ret;
> +
> +	return count;
> +}
> +
> +static ssize_t ina3221_show_current(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;
> +	unsigned int shunt_reg, resistance_uo;
> +	int val, current_ma, shunt_voltage_mv, ret;
> +
> +	shunt_reg = shunt_registers[channel];
> +	resistance_uo = ina->shunt_resistors[channel];
> +	if (resistance_uo == 0) {
> +		current_ma = 0;
> +		goto resistance_is_futile;

Please no funny label names. Also, just make sure that shunt_resistors[]
is never 0 to avoid having to check the value here.

> +	}
> +
> +	ret = ina3221_read_value(ina, shunt_reg, &val);
> +	if (ret)
> +		return ret;
> +	shunt_voltage_mv = val * 40000;
> +
> +	current_ma = DIV_ROUND_CLOSEST(shunt_voltage_mv, resistance_uo);
> +resistance_is_futile:
> +	return snprintf(buf, PAGE_SIZE, "%d\n", current_ma);
> +}
> +
> +static ssize_t ina3221_show_power(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;
> +	unsigned int shunt_reg, bus_reg, resistance_uo;
> +	int val, power_uw, current_ma, shunt_voltage_mv, bus_voltage_mv, ret;
> +
> +	shunt_reg = shunt_registers[channel];
> +	bus_reg = bus_registers[channel];
> +	resistance_uo = ina->shunt_resistors[channel];
> +	if (resistance_uo == 0) {
> +		power_uw = 0;
> +		goto sorry_i_couldnt_resist;
> +	}
> +
> +	ret = ina3221_read_value(ina, shunt_reg, &val);
> +	if (ret)
> +		return ret;
> +	shunt_voltage_mv = val * 40000;
> +
> +	current_ma = DIV_ROUND_CLOSEST(shunt_voltage_mv, resistance_uo);
> +
> +	ret = ina3221_read_value(ina, bus_reg, &val);
> +	if (ret)
> +		return ret;
> +	bus_voltage_mv = val * 8;
> +
> +	power_uw = current_ma * bus_voltage_mv;
> +sorry_i_couldnt_resist:
> +	return snprintf(buf, PAGE_SIZE, "%d\n", power_uw);
> +}
> +
> +static ssize_t ina3221_show_shunt(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;
> +	unsigned int resistance_uo;
> +
> +	resistance_uo = ina->shunt_resistors[channel];
> +
> +	return snprintf(buf, PAGE_SIZE, "%d\n", resistance_uo);
> +}
> +
> +static ssize_t ina3221_set_shunt(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;
> +	int ret;
> +
> +	ret = kstrtouint(buf, 10, &ina->shunt_resistors[channel]);
> +	if (ret)
> +		return ret;
> +
Please don't blindly accept values here. Wrong values should be rejected.
See ina2xx.c for an example.

> +	return count;
> +}
> +
> +/* bus voltages */
> +static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_BUS1);
> +static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_BUS2);
> +static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_BUS3);
> +
> +/* shunt voltages */
> +static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_SHUNT1);
> +static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_SHUNT2);
> +static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_SHUNT3);
> +
> +/* calculated current */
> +static SENSOR_DEVICE_ATTR(curr0_input, S_IRUGO, ina3221_show_current, NULL, INA3221_CHANNEL1);
> +static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina3221_show_current, NULL, INA3221_CHANNEL2);
> +static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ina3221_show_current, NULL, INA3221_CHANNEL3);
> +
> +/* calculated power */
> +static SENSOR_DEVICE_ATTR(power0_input, S_IRUGO, ina3221_show_power, NULL, INA3221_CHANNEL1);
> +static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina3221_show_power, NULL, INA3221_CHANNEL2);
> +static SENSOR_DEVICE_ATTR(power2_input, S_IRUGO, ina3221_show_power, NULL, INA3221_CHANNEL3);
> +
> +/* shunt resistance */
> +static SENSOR_DEVICE_ATTR(shunt0_resistor, (S_IRUGO | S_IWUSR), ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL1);
> +static SENSOR_DEVICE_ATTR(shunt1_resistor, (S_IRUGO | S_IWUSR), ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL2);
> +static SENSOR_DEVICE_ATTR(shunt2_resistor, (S_IRUGO | S_IWUSR), ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL3);
> +
> +/* critical alert */
> +static SENSOR_DEVICE_ATTR(critical0_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_CRIT1);
> +static SENSOR_DEVICE_ATTR(critical1_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_CRIT2);
> +static SENSOR_DEVICE_ATTR(critical2_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_CRIT3);
> +
> +/* warning alert */
> +static SENSOR_DEVICE_ATTR(warning0_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_WARN1);
> +static SENSOR_DEVICE_ATTR(warning1_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_WARN2);
> +static SENSOR_DEVICE_ATTR(warning2_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_WARN3);
> +
> +static struct attribute *ina3221_attrs[] = {
> +	/* channel 1 */
> +	&sensor_dev_attr_in0_input.dev_attr.attr,
> +	&sensor_dev_attr_curr0_input.dev_attr.attr,
> +	&sensor_dev_attr_power0_input.dev_attr.attr,
> +	&sensor_dev_attr_shunt0_resistor.dev_attr.attr,
> +	&sensor_dev_attr_critical0_alarm.dev_attr.attr,
> +	&sensor_dev_attr_warning0_alarm.dev_attr.attr,
> +	&sensor_dev_attr_in3_input.dev_attr.attr,
> +
> +	/* channel 2 */
> +	&sensor_dev_attr_in1_input.dev_attr.attr,
> +	&sensor_dev_attr_curr1_input.dev_attr.attr,
> +	&sensor_dev_attr_power1_input.dev_attr.attr,
> +	&sensor_dev_attr_shunt1_resistor.dev_attr.attr,
> +	&sensor_dev_attr_critical1_alarm.dev_attr.attr,
> +	&sensor_dev_attr_warning1_alarm.dev_attr.attr,
> +	&sensor_dev_attr_in4_input.dev_attr.attr,
> +
> +	/* channel 3 */
> +	&sensor_dev_attr_in2_input.dev_attr.attr,
> +	&sensor_dev_attr_curr2_input.dev_attr.attr,
> +	&sensor_dev_attr_power2_input.dev_attr.attr,
> +	&sensor_dev_attr_shunt2_resistor.dev_attr.attr,
> +	&sensor_dev_attr_critical2_alarm.dev_attr.attr,
> +	&sensor_dev_attr_warning2_alarm.dev_attr.attr,
> +	&sensor_dev_attr_in5_input.dev_attr.attr,
> +
> +	NULL,
> +};
> +ATTRIBUTE_GROUPS(ina3221);
> +
> +static const struct regmap_range ina3221_yes_ranges[] = {
> +	regmap_reg_range(INA3221_SHUNT1, INA3221_BUS3),
> +	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(struct i2c_client *client,
> +			 const struct i2c_device_id *id)
> +{
> +	struct ina3221_data *ina;
> +	struct device *hwmon_dev;
> +	int i, ret;
> +
> +	ina = devm_kzalloc(&client->dev, sizeof(*ina), GFP_KERNEL);
> +	if (!ina)
> +		return -ENOMEM;
> +	i2c_set_clientdata(client, ina);
> +
> +	ina->dev = &client->dev;
> +
> +	ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
> +	if (IS_ERR(ina->regmap)) {
> +		dev_err(ina->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(ina->dev,
> +							 ina->regmap,
> +							 ina3221_reg_fields[i]);
> +		if (IS_ERR(ina->fields[i])) {
> +			dev_err(ina->dev, "Unable to allocate regmap fields\n");
> +			return PTR_ERR(ina->fields[i]);
> +		}
> +	}
> +
> +	ret = regmap_field_write(ina->fields[F_RST], true);
> +	if (ret) {
> +		dev_err(ina->dev, "Unable to reset device\n");
> +		return ret;
> +	}
> +
> +	hwmon_dev = devm_hwmon_device_register_with_groups(ina->dev,
> +							   client->name,
> +							   ina, ina3221_groups);
> +	if (IS_ERR(hwmon_dev)) {
> +		dev_err(ina->dev, "Unable register hwmon device\n");
> +		return PTR_ERR(hwmon_dev);
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct i2c_device_id ina3221_ids[] = {
> +	{ "ina3221", 0 },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(i2c, ina3221_ids);
> +
> +static struct i2c_driver ina3221_i2c_driver = {
> +	.driver = {
> +		.name = INA3221_DRIVER_NAME,
> +	},
> +	.probe = ina3221_probe,
> +	.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");
>

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Andrew F. Davis April 19, 2016, 3:02 p.m. UTC | #2
On 04/19/2016 09:09 AM, Guenter Roeck wrote:
> On 04/11/2016 01:50 PM, Andrew F. Davis wrote:
>> Add support for the the INA3221 26v capable, Triple channel,
>> Bi-Directional, Zero-Drift, Low-/High-Side, Current/Voltage Monitor
>> with I2C interface.
>>
>> Signed-off-by: Andrew F. Davis <afd@ti.com>
>> ---
>>   Documentation/hwmon/ina3221 |  32 ++++
>>   drivers/hwmon/Kconfig       |  11 ++
>>   drivers/hwmon/Makefile      |   1 +
>>   drivers/hwmon/ina3221.c     | 398
>> ++++++++++++++++++++++++++++++++++++++++++++
>>   4 files changed, 442 insertions(+)
>>   create mode 100644 Documentation/hwmon/ina3221
>>   create mode 100644 drivers/hwmon/ina3221.c
>>
>> diff --git a/Documentation/hwmon/ina3221 b/Documentation/hwmon/ina3221
>> new file mode 100644
>> index 0000000..3de3814
>> --- /dev/null
>> +++ b/Documentation/hwmon/ina3221
>> @@ -0,0 +1,32 @@
>> +Kernel driver ina3221
>> +=====================
>> +
>> +Supported chips:
>> +  * Texas Instruments INA3221
>> +    Prefix: 'ina3221'
>> +    Addresses: I2C 0x40 - 0x43
>> +    Datasheet: Publicly available at the Texas Instruments website
>> +               http://www.ti.com/
>> +
>> +Author: Andrew F. Davis <afd@ti.com>
>> +
>> +Description
>> +-----------
>> +
>> +The Texas Instruments INA3221 monitors voltage, current, and power on
>> the high
>> +side of up to three D.C. power supplies. The INA3221 monitors both
>> shunt drop
>> +and supply voltage, with programmable conversion times and averaging,
>> current
>> +and power are calculated host-side from these.
>> +
>> +Sysfs entries
>> +-------------
>> +
>> +in[012]_input           Bus voltages(mV) for channels 1, 2, and 3
>> respectively
>> +in[345]_input           Shunt voltages(mV) for channels 1, 2, and 3
>> respectively
>> +curr[012]_input         Current(mA) measurement for channels 1, 2,
>> and 3 respectively
> 
> Numbering for currents is [123], not [012].
> 

Okay, I'm guessing I should then change in to match?

>> +power[012]_input        Power(uW) measurement for channels 1, 2, and
>> 3 respectively
> 
> hwmon only reports what is there, and doesn't do calculations. The chip
> doesn't report
> the power, so please drop the power attributes.
> 

Sure

>> +shunt[012]_resistor     Shunt resistance(uOhm) for channels 1, 2, and
>> 3 respectively
> 
> This should be a backup, if neither devicetree nor platform data are
> provided,
> not a primary means to provide the shunt resistor value. Also, there
> should be a default,
> to make sure the driver provides useful data even if nothing is configured.
> See ina2xx.c for an example.
> 

I'll add DT support for this.

>> +critical[012]_alarm     Critical alert voltage(mV) setting, activated
>> when the
>> +                        respective shunt voltage is above this value.
>> +warning[012]_alarm      Warning alert voltage(mV) setting, activated
>> when the
>> +                        respective shunt voltage average is above
>> this value.
> 
> Alarm attributes report the alarm status, not voltages. Use in[012]_max and
> in[012]_crit attributes to set the limits. Report the alarm status with
> in[012]_max_alarm and in[012]_crit_alarm (from register 0x0f, bit 9-7 and
> 5-3).
> 

Will fix.

>> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>> index 5c2d13a..de08242 100644
>> --- a/drivers/hwmon/Kconfig
>> +++ b/drivers/hwmon/Kconfig
>> @@ -1503,6 +1503,17 @@ config SENSORS_INA2XX
>>         This driver can also be built as a module.  If so, the module
>>         will be called ina2xx.
>>
>> +config SENSORS_INA3221
>> +    tristate "Texas Instruments INA3221 Triple Power Monitor"
>> +    depends on I2C
>> +    select REGMAP_I2C
>> +    help
>> +      If you say yes here you get support for  the TI INA3221 Triple
>> Power
>> +      Monitor.
>> +
>> +      This driver can also be built as a module.  If so, the module
>> +      will be called ina3221.
>> +
>>   config SENSORS_TC74
>>       tristate "Microchip TC74"
>>       depends on I2C
>> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
>> index 58cc3ac..83e8ab0 100644
>> --- a/drivers/hwmon/Makefile
>> +++ b/drivers/hwmon/Makefile
>> @@ -77,6 +77,7 @@ obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o
>>   obj-$(CONFIG_SENSORS_IIO_HWMON) += iio_hwmon.o
>>   obj-$(CONFIG_SENSORS_INA209)    += ina209.o
>>   obj-$(CONFIG_SENSORS_INA2XX)    += ina2xx.o
>> +obj-$(CONFIG_SENSORS_INA3221)    += ina3221.o
>>   obj-$(CONFIG_SENSORS_IT87)    += it87.o
>>   obj-$(CONFIG_SENSORS_JC42)    += jc42.o
>>   obj-$(CONFIG_SENSORS_JZ4740)    += jz4740-hwmon.o
>> diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
>> new file mode 100644
>> index 0000000..763e23b
>> --- /dev/null
>> +++ b/drivers/hwmon/ina3221.c
>> @@ -0,0 +1,398 @@
>> +/*
>> + * INA3221 Triple Current/Voltage Monitor
>> + *
>> + * Copyright (C) 2016 Texas Instruments Incorporated -
>> http://www.ti.com/
>> + *    Andrew F. Davis <afd@ti.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * This program is distributed in the hope that it will be useful, but
>> + * WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> + * General Public License for more details.
>> + */
>> +
>> +#include <linux/i2c.h>
>> +#include <linux/module.h>
>> +#include <linux/regmap.h>
>> +
>> +#include <linux/hwmon.h>
>> +#include <linux/hwmon-sysfs.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_SHUNT_SUM_LIMIT        0x0e
>> +#define INA3221_MASK_ENABLE        0x0f
>> +#define INA3221_POWERV_HLIMIT        0x10
>> +#define INA3221_POWERV_LLIMIT        0x11
>> +
>> +#define INA3221_CONFIG_MODE_SHUNT    BIT(1)
>> +#define INA3221_CONFIG_MODE_BUS        BIT(2)
>> +#define INA3221_CONFIG_MODE_CONTINUOUS    BIT(3)
>> +
>> +enum ina3221_fields {
>> +    /* Configuration */
>> +    F_MODE, F_SHUNT_CT, F_BUS_CT, F_AVG,
>> +    F_CHAN3_EN, F_CHAN2_EN, F_CHAN1_EN, F_RST,
>> +
>> +    /* sentinel */
>> +    F_MAX_FIELDS
>> +};
>> +
>> +static const struct reg_field ina3221_reg_fields[] = {
>> +    [F_MODE]    = REG_FIELD(INA3221_CONFIG, 0, 2),
>> +    [F_SHUNT_CT]    = REG_FIELD(INA3221_CONFIG, 3, 5),
>> +    [F_BUS_CT]    = REG_FIELD(INA3221_CONFIG, 6, 8),
>> +    [F_AVG]        = REG_FIELD(INA3221_CONFIG, 9, 11),
>> +    [F_CHAN3_EN]    = REG_FIELD(INA3221_CONFIG, 12, 12),
>> +    [F_CHAN2_EN]    = REG_FIELD(INA3221_CONFIG, 13, 13),
>> +    [F_CHAN1_EN]    = REG_FIELD(INA3221_CONFIG, 14, 14),
>> +    [F_RST]        = REG_FIELD(INA3221_CONFIG, 15, 15),
>> +};
>> +
>> +enum ina3221_channels {
>> +    INA3221_CHANNEL1,
>> +    INA3221_CHANNEL2,
>> +    INA3221_CHANNEL3,
>> +    INA3221_NUM_CHANNELS
>> +};
>> +
>> +static const int shunt_registers[] = {
>> +    [INA3221_CHANNEL1] = INA3221_SHUNT1,
>> +    [INA3221_CHANNEL2] = INA3221_SHUNT2,
>> +    [INA3221_CHANNEL3] = INA3221_SHUNT3,
>> +};
>> +
>> +static const int bus_registers[] = {
>> +    [INA3221_CHANNEL1] = INA3221_BUS1,
>> +    [INA3221_CHANNEL2] = INA3221_BUS2,
>> +    [INA3221_CHANNEL3] = INA3221_BUS3,
>> +};
>> +
>> +/**
>> + * struct ina3221_data - device specific information
>> + * @dev: Device structure
>> + * @regmap: Register map of the device
>> + * @fields: Register fields of the device
>> + */
>> +struct ina3221_data {
>> +    struct device *dev;
>> +    struct regmap *regmap;
>> +    struct regmap_field *fields[F_MAX_FIELDS];
>> +    unsigned int shunt_resistors[INA3221_NUM_CHANNELS];
>> +};
>> +
>> +static int ina3221_read_value(struct ina3221_data *ina, unsigned int
>> reg,
>> +                  unsigned int *val)
>> +{
>> +    unsigned int regval;
>> +    int ret;
>> +
>> +    ret = regmap_read(ina->regmap, reg, &regval);
>> +    if (ret)
>> +        return ret;
>> +
>> +    *val = sign_extend32(regval >> 3, 12);
>> +
>> +    return 0;
>> +}
>> +
>> +static ssize_t ina3221_show_voltage(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 reg = sd_attr->index;
>> +    int val, voltage_mv, ret;
>> +
>> +    ret = ina3221_read_value(ina, reg, &val);
>> +    if (ret)
>> +        return ret;
>> +
>> +    if (reg == INA3221_BUS1 ||
>> +        reg == INA3221_BUS2 ||
>> +        reg == INA3221_BUS3)
>> +        voltage_mv = val * 8;
>> +    else
>> +        voltage_mv = DIV_ROUND_CLOSEST(val * 40, 1000);
>> +
>> +    return snprintf(buf, PAGE_SIZE, "%d\n", voltage_mv);
>> +}
>> +
>> +static ssize_t ina3221_set_voltage(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 reg = sd_attr->index;
>> +    int val, ret;
>> +
>> +    ret = kstrtoint(buf, 10, &val);
>> +    if (ret)
>> +        return ret;
>> +
> Please clamp the value to valid voltage range.
> 

ACK

>> +    val = DIV_ROUND_CLOSEST(val, 40000) << 3;
>> +
>> +    ret = regmap_write(ina->regmap, reg, val);
>> +    if (ret)
>> +        return ret;
>> +
>> +    return count;
>> +}
>> +
>> +static ssize_t ina3221_show_current(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;
>> +    unsigned int shunt_reg, resistance_uo;
>> +    int val, current_ma, shunt_voltage_mv, ret;
>> +
>> +    shunt_reg = shunt_registers[channel];
>> +    resistance_uo = ina->shunt_resistors[channel];
>> +    if (resistance_uo == 0) {
>> +        current_ma = 0;
>> +        goto resistance_is_futile;
> 
> Please no funny label names.

http://i.imgur.com/2cZhiM4.jpg :)

> Also, just make sure that shunt_resistors[]
> is never 0 to avoid having to check the value here.
> 

That works, will fix.

>> +    }
>> +
>> +    ret = ina3221_read_value(ina, shunt_reg, &val);
>> +    if (ret)
>> +        return ret;
>> +    shunt_voltage_mv = val * 40000;
>> +
>> +    current_ma = DIV_ROUND_CLOSEST(shunt_voltage_mv, resistance_uo);
>> +resistance_is_futile:
>> +    return snprintf(buf, PAGE_SIZE, "%d\n", current_ma);
>> +}
>> +
>> +static ssize_t ina3221_show_power(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;
>> +    unsigned int shunt_reg, bus_reg, resistance_uo;
>> +    int val, power_uw, current_ma, shunt_voltage_mv, bus_voltage_mv,
>> ret;
>> +
>> +    shunt_reg = shunt_registers[channel];
>> +    bus_reg = bus_registers[channel];
>> +    resistance_uo = ina->shunt_resistors[channel];
>> +    if (resistance_uo == 0) {
>> +        power_uw = 0;
>> +        goto sorry_i_couldnt_resist;
>> +    }
>> +
>> +    ret = ina3221_read_value(ina, shunt_reg, &val);
>> +    if (ret)
>> +        return ret;
>> +    shunt_voltage_mv = val * 40000;
>> +
>> +    current_ma = DIV_ROUND_CLOSEST(shunt_voltage_mv, resistance_uo);
>> +
>> +    ret = ina3221_read_value(ina, bus_reg, &val);
>> +    if (ret)
>> +        return ret;
>> +    bus_voltage_mv = val * 8;
>> +
>> +    power_uw = current_ma * bus_voltage_mv;
>> +sorry_i_couldnt_resist:
>> +    return snprintf(buf, PAGE_SIZE, "%d\n", power_uw);
>> +}
>> +
>> +static ssize_t ina3221_show_shunt(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;
>> +    unsigned int resistance_uo;
>> +
>> +    resistance_uo = ina->shunt_resistors[channel];
>> +
>> +    return snprintf(buf, PAGE_SIZE, "%d\n", resistance_uo);
>> +}
>> +
>> +static ssize_t ina3221_set_shunt(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;
>> +    int ret;
>> +
>> +    ret = kstrtouint(buf, 10, &ina->shunt_resistors[channel]);
>> +    if (ret)
>> +        return ret;
>> +
> Please don't blindly accept values here. Wrong values should be rejected.
> See ina2xx.c for an example.
> 

I'll fix that and post v2 here shortly.

Thanks,
Andrew
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diff mbox

Patch

diff --git a/Documentation/hwmon/ina3221 b/Documentation/hwmon/ina3221
new file mode 100644
index 0000000..3de3814
--- /dev/null
+++ b/Documentation/hwmon/ina3221
@@ -0,0 +1,32 @@ 
+Kernel driver ina3221
+=====================
+
+Supported chips:
+  * Texas Instruments INA3221
+    Prefix: 'ina3221'
+    Addresses: I2C 0x40 - 0x43
+    Datasheet: Publicly available at the Texas Instruments website
+               http://www.ti.com/
+
+Author: Andrew F. Davis <afd@ti.com>
+
+Description
+-----------
+
+The Texas Instruments INA3221 monitors voltage, current, and power on the high
+side of up to three D.C. power supplies. The INA3221 monitors both shunt drop
+and supply voltage, with programmable conversion times and averaging, current
+and power are calculated host-side from these.
+
+Sysfs entries
+-------------
+
+in[012]_input           Bus voltages(mV) for channels 1, 2, and 3 respectively
+in[345]_input           Shunt voltages(mV) for channels 1, 2, and 3 respectively
+curr[012]_input         Current(mA) measurement for channels 1, 2, and 3 respectively
+power[012]_input        Power(uW) measurement for channels 1, 2, and 3 respectively
+shunt[012]_resistor     Shunt resistance(uOhm) for channels 1, 2, and 3 respectively
+critical[012]_alarm     Critical alert voltage(mV) setting, activated when the
+                        respective shunt voltage is above this value.
+warning[012]_alarm      Warning alert voltage(mV) setting, activated when the
+                        respective shunt voltage average is above this value.
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 5c2d13a..de08242 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1503,6 +1503,17 @@  config SENSORS_INA2XX
 	  This driver can also be built as a module.  If so, the module
 	  will be called ina2xx.
 
+config SENSORS_INA3221
+	tristate "Texas Instruments INA3221 Triple Power Monitor"
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  If you say yes here you get support for  the TI INA3221 Triple Power
+	  Monitor.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called ina3221.
+
 config SENSORS_TC74
 	tristate "Microchip TC74"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 58cc3ac..83e8ab0 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -77,6 +77,7 @@  obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o
 obj-$(CONFIG_SENSORS_IIO_HWMON) += iio_hwmon.o
 obj-$(CONFIG_SENSORS_INA209)	+= ina209.o
 obj-$(CONFIG_SENSORS_INA2XX)	+= ina2xx.o
+obj-$(CONFIG_SENSORS_INA3221)	+= ina3221.o
 obj-$(CONFIG_SENSORS_IT87)	+= it87.o
 obj-$(CONFIG_SENSORS_JC42)	+= jc42.o
 obj-$(CONFIG_SENSORS_JZ4740)	+= jz4740-hwmon.o
diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
new file mode 100644
index 0000000..763e23b
--- /dev/null
+++ b/drivers/hwmon/ina3221.c
@@ -0,0 +1,398 @@ 
+/*
+ * INA3221 Triple Current/Voltage Monitor
+ *
+ * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
+ *	Andrew F. Davis <afd@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.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_SHUNT_SUM_LIMIT		0x0e
+#define INA3221_MASK_ENABLE		0x0f
+#define INA3221_POWERV_HLIMIT		0x10
+#define INA3221_POWERV_LLIMIT		0x11
+
+#define INA3221_CONFIG_MODE_SHUNT	BIT(1)
+#define INA3221_CONFIG_MODE_BUS		BIT(2)
+#define INA3221_CONFIG_MODE_CONTINUOUS	BIT(3)
+
+enum ina3221_fields {
+	/* Configuration */
+	F_MODE, F_SHUNT_CT, F_BUS_CT, F_AVG,
+	F_CHAN3_EN, F_CHAN2_EN, F_CHAN1_EN, F_RST,
+
+	/* sentinel */
+	F_MAX_FIELDS
+};
+
+static const struct reg_field ina3221_reg_fields[] = {
+	[F_MODE]	= REG_FIELD(INA3221_CONFIG, 0, 2),
+	[F_SHUNT_CT]	= REG_FIELD(INA3221_CONFIG, 3, 5),
+	[F_BUS_CT]	= REG_FIELD(INA3221_CONFIG, 6, 8),
+	[F_AVG]		= REG_FIELD(INA3221_CONFIG, 9, 11),
+	[F_CHAN3_EN]	= REG_FIELD(INA3221_CONFIG, 12, 12),
+	[F_CHAN2_EN]	= REG_FIELD(INA3221_CONFIG, 13, 13),
+	[F_CHAN1_EN]	= REG_FIELD(INA3221_CONFIG, 14, 14),
+	[F_RST]		= REG_FIELD(INA3221_CONFIG, 15, 15),
+};
+
+enum ina3221_channels {
+	INA3221_CHANNEL1,
+	INA3221_CHANNEL2,
+	INA3221_CHANNEL3,
+	INA3221_NUM_CHANNELS
+};
+
+static const int shunt_registers[] = {
+	[INA3221_CHANNEL1] = INA3221_SHUNT1,
+	[INA3221_CHANNEL2] = INA3221_SHUNT2,
+	[INA3221_CHANNEL3] = INA3221_SHUNT3,
+};
+
+static const int bus_registers[] = {
+	[INA3221_CHANNEL1] = INA3221_BUS1,
+	[INA3221_CHANNEL2] = INA3221_BUS2,
+	[INA3221_CHANNEL3] = INA3221_BUS3,
+};
+
+/**
+ * struct ina3221_data - device specific information
+ * @dev: Device structure
+ * @regmap: Register map of the device
+ * @fields: Register fields of the device
+ */
+struct ina3221_data {
+	struct device *dev;
+	struct regmap *regmap;
+	struct regmap_field *fields[F_MAX_FIELDS];
+	unsigned int shunt_resistors[INA3221_NUM_CHANNELS];
+};
+
+static int ina3221_read_value(struct ina3221_data *ina, unsigned int reg,
+			      unsigned int *val)
+{
+	unsigned int regval;
+	int ret;
+
+	ret = regmap_read(ina->regmap, reg, &regval);
+	if (ret)
+		return ret;
+
+	*val = sign_extend32(regval >> 3, 12);
+
+	return 0;
+}
+
+static ssize_t ina3221_show_voltage(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 reg = sd_attr->index;
+	int val, voltage_mv, ret;
+
+	ret = ina3221_read_value(ina, reg, &val);
+	if (ret)
+		return ret;
+
+	if (reg == INA3221_BUS1 ||
+	    reg == INA3221_BUS2 ||
+	    reg == INA3221_BUS3)
+		voltage_mv = val * 8;
+	else
+		voltage_mv = DIV_ROUND_CLOSEST(val * 40, 1000);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", voltage_mv);
+}
+
+static ssize_t ina3221_set_voltage(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 reg = sd_attr->index;
+	int val, ret;
+
+	ret = kstrtoint(buf, 10, &val);
+	if (ret)
+		return ret;
+
+	val = DIV_ROUND_CLOSEST(val, 40000) << 3;
+
+	ret = regmap_write(ina->regmap, reg, val);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t ina3221_show_current(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;
+	unsigned int shunt_reg, resistance_uo;
+	int val, current_ma, shunt_voltage_mv, ret;
+
+	shunt_reg = shunt_registers[channel];
+	resistance_uo = ina->shunt_resistors[channel];
+	if (resistance_uo == 0) {
+		current_ma = 0;
+		goto resistance_is_futile;
+	}
+
+	ret = ina3221_read_value(ina, shunt_reg, &val);
+	if (ret)
+		return ret;
+	shunt_voltage_mv = val * 40000;
+
+	current_ma = DIV_ROUND_CLOSEST(shunt_voltage_mv, resistance_uo);
+resistance_is_futile:
+	return snprintf(buf, PAGE_SIZE, "%d\n", current_ma);
+}
+
+static ssize_t ina3221_show_power(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;
+	unsigned int shunt_reg, bus_reg, resistance_uo;
+	int val, power_uw, current_ma, shunt_voltage_mv, bus_voltage_mv, ret;
+
+	shunt_reg = shunt_registers[channel];
+	bus_reg = bus_registers[channel];
+	resistance_uo = ina->shunt_resistors[channel];
+	if (resistance_uo == 0) {
+		power_uw = 0;
+		goto sorry_i_couldnt_resist;
+	}
+
+	ret = ina3221_read_value(ina, shunt_reg, &val);
+	if (ret)
+		return ret;
+	shunt_voltage_mv = val * 40000;
+
+	current_ma = DIV_ROUND_CLOSEST(shunt_voltage_mv, resistance_uo);
+
+	ret = ina3221_read_value(ina, bus_reg, &val);
+	if (ret)
+		return ret;
+	bus_voltage_mv = val * 8;
+
+	power_uw = current_ma * bus_voltage_mv;
+sorry_i_couldnt_resist:
+	return snprintf(buf, PAGE_SIZE, "%d\n", power_uw);
+}
+
+static ssize_t ina3221_show_shunt(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;
+	unsigned int resistance_uo;
+
+	resistance_uo = ina->shunt_resistors[channel];
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", resistance_uo);
+}
+
+static ssize_t ina3221_set_shunt(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;
+	int ret;
+
+	ret = kstrtouint(buf, 10, &ina->shunt_resistors[channel]);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+/* bus voltages */
+static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_BUS1);
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_BUS2);
+static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_BUS3);
+
+/* shunt voltages */
+static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_SHUNT1);
+static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_SHUNT2);
+static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, ina3221_show_voltage, NULL, INA3221_SHUNT3);
+
+/* calculated current */
+static SENSOR_DEVICE_ATTR(curr0_input, S_IRUGO, ina3221_show_current, NULL, INA3221_CHANNEL1);
+static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina3221_show_current, NULL, INA3221_CHANNEL2);
+static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ina3221_show_current, NULL, INA3221_CHANNEL3);
+
+/* calculated power */
+static SENSOR_DEVICE_ATTR(power0_input, S_IRUGO, ina3221_show_power, NULL, INA3221_CHANNEL1);
+static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina3221_show_power, NULL, INA3221_CHANNEL2);
+static SENSOR_DEVICE_ATTR(power2_input, S_IRUGO, ina3221_show_power, NULL, INA3221_CHANNEL3);
+
+/* shunt resistance */
+static SENSOR_DEVICE_ATTR(shunt0_resistor, (S_IRUGO | S_IWUSR), ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL1);
+static SENSOR_DEVICE_ATTR(shunt1_resistor, (S_IRUGO | S_IWUSR), ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL2);
+static SENSOR_DEVICE_ATTR(shunt2_resistor, (S_IRUGO | S_IWUSR), ina3221_show_shunt, ina3221_set_shunt, INA3221_CHANNEL3);
+
+/* critical alert */
+static SENSOR_DEVICE_ATTR(critical0_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_CRIT1);
+static SENSOR_DEVICE_ATTR(critical1_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_CRIT2);
+static SENSOR_DEVICE_ATTR(critical2_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_CRIT3);
+
+/* warning alert */
+static SENSOR_DEVICE_ATTR(warning0_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_WARN1);
+static SENSOR_DEVICE_ATTR(warning1_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_WARN2);
+static SENSOR_DEVICE_ATTR(warning2_alarm, (S_IRUGO | S_IWUSR), ina3221_show_voltage, ina3221_set_voltage, INA3221_WARN3);
+
+static struct attribute *ina3221_attrs[] = {
+	/* channel 1 */
+	&sensor_dev_attr_in0_input.dev_attr.attr,
+	&sensor_dev_attr_curr0_input.dev_attr.attr,
+	&sensor_dev_attr_power0_input.dev_attr.attr,
+	&sensor_dev_attr_shunt0_resistor.dev_attr.attr,
+	&sensor_dev_attr_critical0_alarm.dev_attr.attr,
+	&sensor_dev_attr_warning0_alarm.dev_attr.attr,
+	&sensor_dev_attr_in3_input.dev_attr.attr,
+
+	/* channel 2 */
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	&sensor_dev_attr_curr1_input.dev_attr.attr,
+	&sensor_dev_attr_power1_input.dev_attr.attr,
+	&sensor_dev_attr_shunt1_resistor.dev_attr.attr,
+	&sensor_dev_attr_critical1_alarm.dev_attr.attr,
+	&sensor_dev_attr_warning1_alarm.dev_attr.attr,
+	&sensor_dev_attr_in4_input.dev_attr.attr,
+
+	/* channel 3 */
+	&sensor_dev_attr_in2_input.dev_attr.attr,
+	&sensor_dev_attr_curr2_input.dev_attr.attr,
+	&sensor_dev_attr_power2_input.dev_attr.attr,
+	&sensor_dev_attr_shunt2_resistor.dev_attr.attr,
+	&sensor_dev_attr_critical2_alarm.dev_attr.attr,
+	&sensor_dev_attr_warning2_alarm.dev_attr.attr,
+	&sensor_dev_attr_in5_input.dev_attr.attr,
+
+	NULL,
+};
+ATTRIBUTE_GROUPS(ina3221);
+
+static const struct regmap_range ina3221_yes_ranges[] = {
+	regmap_reg_range(INA3221_SHUNT1, INA3221_BUS3),
+	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(struct i2c_client *client,
+			 const struct i2c_device_id *id)
+{
+	struct ina3221_data *ina;
+	struct device *hwmon_dev;
+	int i, ret;
+
+	ina = devm_kzalloc(&client->dev, sizeof(*ina), GFP_KERNEL);
+	if (!ina)
+		return -ENOMEM;
+	i2c_set_clientdata(client, ina);
+
+	ina->dev = &client->dev;
+
+	ina->regmap = devm_regmap_init_i2c(client, &ina3221_regmap_config);
+	if (IS_ERR(ina->regmap)) {
+		dev_err(ina->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(ina->dev,
+							 ina->regmap,
+							 ina3221_reg_fields[i]);
+		if (IS_ERR(ina->fields[i])) {
+			dev_err(ina->dev, "Unable to allocate regmap fields\n");
+			return PTR_ERR(ina->fields[i]);
+		}
+	}
+
+	ret = regmap_field_write(ina->fields[F_RST], true);
+	if (ret) {
+		dev_err(ina->dev, "Unable to reset device\n");
+		return ret;
+	}
+
+	hwmon_dev = devm_hwmon_device_register_with_groups(ina->dev,
+							   client->name,
+							   ina, ina3221_groups);
+	if (IS_ERR(hwmon_dev)) {
+		dev_err(ina->dev, "Unable register hwmon device\n");
+		return PTR_ERR(hwmon_dev);
+	}
+
+	return 0;
+}
+
+static const struct i2c_device_id ina3221_ids[] = {
+	{ "ina3221", 0 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(i2c, ina3221_ids);
+
+static struct i2c_driver ina3221_i2c_driver = {
+	.driver = {
+		.name = INA3221_DRIVER_NAME,
+	},
+	.probe = ina3221_probe,
+	.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");