hwmon: INA219 and INA226 support (f7c2fe38) · Commits · e / devices / android_kernel_xiaomi_markw

Documentation/hwmon/ina2xx

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		Kernel driver ina2xx
		====================

		Supported chips:
		* Texas Instruments INA219
		Prefix: 'ina219'
		Addresses: I2C 0x40 - 0x4f
		Datasheet: Publicly available at the Texas Instruments website
		http://www.ti.com/

		* Texas Instruments INA226
		Prefix: 'ina226'
		Addresses: I2C 0x40 - 0x4f
		Datasheet: Publicly available at the Texas Instruments website
		http://www.ti.com/

		Author: Lothar Felten <l-felten@ti.com>

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

		The INA219 is a high-side current shunt and power monitor with an I2C
		interface. The INA219 monitors both shunt drop and supply voltage, with
		programmable conversion times and filtering.

		The INA226 is a current shunt and power monitor with an I2C interface.
		The INA226 monitors both a shunt voltage drop and bus supply voltage.

		The shunt value in micro-ohms can be set via platform data.

drivers/hwmon/Kconfig

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		@@ -1102,6 +1102,19 @@ config SENSORS_AMC6821
		This driver can also be build as a module. If so, the module
		will be called amc6821.

		config SENSORS_INA2XX
		tristate "Texas Instruments INA219, INA226"
		depends on I2C && EXPERIMENTAL
		help
		If you say yes here you get support for INA219 and INA226 power
		monitor chips.

		The INA2xx driver is configured for the default configuration of
		the part as described in the datasheet.
		Default value for Rshunt is 10 mOhms.
		This driver can also be built as a module. If so, the module
		will be called ina2xx.

		config SENSORS_THMC50
		tristate "Texas Instruments THMC50 / Analog Devices ADM1022"
		depends on I2C

drivers/hwmon/Makefile

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		@@ -62,6 +62,7 @@ obj-$(CONFIG_SENSORS_ULTRA45) += ultra45_env.o
		obj-$(CONFIG_SENSORS_I5K_AMB) += i5k_amb.o
		obj-$(CONFIG_SENSORS_IBMAEM) += ibmaem.o
		obj-$(CONFIG_SENSORS_IBMPEX) += ibmpex.o
		obj-$(CONFIG_SENSORS_INA2XX) += ina2xx.o
		obj-$(CONFIG_SENSORS_IT87) += it87.o
		obj-$(CONFIG_SENSORS_JC42) += jc42.o
		obj-$(CONFIG_SENSORS_JZ4740) += jz4740-hwmon.o

drivers/hwmon/ina2xx.c

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		/*
		* Driver for Texas Instruments INA219, INA226 power monitor chips
		*
		* INA219:
		* Zero Drift Bi-Directional Current/Power Monitor with I2C Interface
		* Datasheet: http://www.ti.com/product/ina219
		*
		* INA226:
		* Bi-Directional Current/Power Monitor with I2C Interface
		* Datasheet: http://www.ti.com/product/ina226
		*
		* Copyright (C) 2012 Lothar Felten <l-felten@ti.com>
		* Thanks to Jan Volkering
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; version 2 of the License.
		*/

		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/init.h>
		#include <linux/err.h>
		#include <linux/slab.h>
		#include <linux/i2c.h>
		#include <linux/hwmon.h>
		#include <linux/hwmon-sysfs.h>

		#include <linux/platform_data/ina2xx.h>

		/* common register definitions */
		#define INA2XX_CONFIG 0x00
		#define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */
		#define INA2XX_BUS_VOLTAGE 0x02 /* readonly */
		#define INA2XX_POWER 0x03 /* readonly */
		#define INA2XX_CURRENT 0x04 /* readonly */
		#define INA2XX_CALIBRATION 0x05

		/* INA226 register definitions */
		#define INA226_MASK_ENABLE 0x06
		#define INA226_ALERT_LIMIT 0x07
		#define INA226_DIE_ID 0xFF


		/* register count */
		#define INA219_REGISTERS 6
		#define INA226_REGISTERS 8

		#define INA2XX_MAX_REGISTERS 8

		/* settings - depend on use case */
		#define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
		#define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */

		/* worst case is 68.10 ms (~14.6Hz, ina219) */
		#define INA2XX_CONVERSION_RATE 15

		enum ina2xx_ids { ina219, ina226 };

		struct ina2xx_data {
		struct device *hwmon_dev;

		struct mutex update_lock;
		bool valid;
		unsigned long last_updated;

		int kind;
		int registers;
		u16 regs[INA2XX_MAX_REGISTERS];
		};

		int ina2xx_read_word(struct i2c_client *client, int reg)
		{
		int val = i2c_smbus_read_word_data(client, reg);
		if (unlikely(val < 0)) {
		dev_dbg(&client->dev,
		"Failed to read register: %d\n", reg);
		return val;
		}
		return be16_to_cpu(val);
		}

		void ina2xx_write_word(struct i2c_client *client, int reg, int data)
		{
		i2c_smbus_write_word_data(client, reg, cpu_to_be16(data));
		}

		static struct ina2xx_data ina2xx_update_device(struct device dev)
		{
		struct i2c_client *client = to_i2c_client(dev);
		struct ina2xx_data *data = i2c_get_clientdata(client);
		struct ina2xx_data *ret = data;

		mutex_lock(&data->update_lock);

		if (time_after(jiffies, data->last_updated +
		HZ / INA2XX_CONVERSION_RATE) \|\| !data->valid) {

		int i;

		dev_dbg(&client->dev, "Starting ina2xx update\n");

		/* Read all registers */
		for (i = 0; i < data->registers; i++) {
		int rv = ina2xx_read_word(client, i);
		if (rv < 0) {
		ret = ERR_PTR(rv);
		goto abort;
		}
		data->regs[i] = rv;
		}
		data->last_updated = jiffies;
		data->valid = 1;
		}
		abort:
		mutex_unlock(&data->update_lock);
		return ret;
		}

		static int ina219_get_value(struct ina2xx_data *data, u8 reg)
		{
		/*
		* calculate exact value for the given register
		* we assume default power-on reset settings:
		* bus voltage range 32V
		* gain = /8
		* adc 1 & 2 -> conversion time 532uS
		* mode is continuous shunt and bus
		* calibration value is INA219_CALIBRATION_VALUE
		*/
		int val = data->regs[reg];

		switch (reg) {
		case INA2XX_SHUNT_VOLTAGE:
		/* LSB=10uV. Convert to mV. */
		val = DIV_ROUND_CLOSEST(val, 100);
		break;
		case INA2XX_BUS_VOLTAGE:
		/* LSB=4mV. Register is not right aligned, convert to mV. */
		val = (val >> 3) * 4;
		break;
		case INA2XX_POWER:
		/* LSB=20mW. Convert to uW */
		val = val * 20 * 1000;
		break;
		case INA2XX_CURRENT:
		/* LSB=1mA (selected). Is in mA */
		break;
		default:
		/* programmer goofed */
		WARN_ON_ONCE(1);
		val = 0;
		break;
		}

		return val;
		}

		static int ina226_get_value(struct ina2xx_data *data, u8 reg)
		{
		/*
		* calculate exact value for the given register
		* we assume default power-on reset settings:
		* bus voltage range 32V
		* gain = /8
		* adc 1 & 2 -> conversion time 532uS
		* mode is continuous shunt and bus
		* calibration value is INA226_CALIBRATION_VALUE
		*/
		int val = data->regs[reg];

		switch (reg) {
		case INA2XX_SHUNT_VOLTAGE:
		/* LSB=2.5uV. Convert to mV. */
		val = DIV_ROUND_CLOSEST(val, 400);
		break;
		case INA2XX_BUS_VOLTAGE:
		/* LSB=1.25mV. Convert to mV. */
		val = val + DIV_ROUND_CLOSEST(val, 4);
		break;
		case INA2XX_POWER:
		/* LSB=25mW. Convert to uW */
		val = val * 25 * 1000;
		break;
		case INA2XX_CURRENT:
		/* LSB=1mA (selected). Is in mA */
		break;
		default:
		/* programmer goofed */
		WARN_ON_ONCE(1);
		val = 0;
		break;
		}

		return val;
		}

		static ssize_t ina2xx_show_value(struct device *dev,
		struct device_attribute da, char buf)
		{
		struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
		struct ina2xx_data *data = ina2xx_update_device(dev);
		int value = 0;

		if (IS_ERR(data))
		return PTR_ERR(data);

		switch (data->kind) {
		case ina219:
		value = ina219_get_value(data, attr->index);
		break;
		case ina226:
		value = ina226_get_value(data, attr->index);
		break;
		default:
		WARN_ON_ONCE(1);
		break;
		}
		return snprintf(buf, PAGE_SIZE, "%d\n", value);
		}

		/* shunt voltage */
		static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, \
		ina2xx_show_value, NULL, INA2XX_SHUNT_VOLTAGE);

		/* bus voltage */
		static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, \
		ina2xx_show_value, NULL, INA2XX_BUS_VOLTAGE);

		/* calculated current */
		static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, \
		ina2xx_show_value, NULL, INA2XX_CURRENT);

		/* calculated power */
		static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, \
		ina2xx_show_value, NULL, INA2XX_POWER);

		/* pointers to created device attributes */
		static struct attribute *ina2xx_attributes[] = {
		&sensor_dev_attr_in0_input.dev_attr.attr,
		&sensor_dev_attr_in1_input.dev_attr.attr,
		&sensor_dev_attr_curr1_input.dev_attr.attr,
		&sensor_dev_attr_power1_input.dev_attr.attr,
		NULL,
		};

		static const struct attribute_group ina2xx_group = {
		.attrs = ina2xx_attributes,
		};

		static int ina2xx_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
		{
		struct i2c_adapter *adapter = client->adapter;
		struct ina2xx_data *data;
		struct ina2xx_platform_data *pdata;
		int ret = 0;
		long shunt = 10000; /* default shunt value 10mOhms */

		if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
		return -ENODEV;

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

		if (client->dev.platform_data) {
		pdata =
		(struct ina2xx_platform_data *)client->dev.platform_data;
		shunt = pdata->shunt_uohms;
		}

		if (shunt <= 0)
		return -ENODEV;

		/* set the device type */
		data->kind = id->driver_data;

		switch (data->kind) {
		case ina219:
		/* device configuration */
		ina2xx_write_word(client, INA2XX_CONFIG, INA219_CONFIG_DEFAULT);

		/* set current LSB to 1mA, shunt is in uOhms */
		/* (equation 13 in datasheet) */
		ina2xx_write_word(client, INA2XX_CALIBRATION, 40960000 / shunt);
		dev_info(&client->dev,
		"power monitor INA219 (Rshunt = %li uOhm)\n", shunt);
		data->registers = INA219_REGISTERS;
		break;
		case ina226:
		/* device configuration */
		ina2xx_write_word(client, INA2XX_CONFIG, INA226_CONFIG_DEFAULT);

		/* set current LSB to 1mA, shunt is in uOhms */
		/* (equation 1 in datasheet)*/
		ina2xx_write_word(client, INA2XX_CALIBRATION, 5120000 / shunt);
		dev_info(&client->dev,
		"power monitor INA226 (Rshunt = %li uOhm)\n", shunt);
		data->registers = INA226_REGISTERS;
		break;
		default:
		/* unknown device id */
		return -ENODEV;
		}

		i2c_set_clientdata(client, data);
		mutex_init(&data->update_lock);

		ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group);
		if (ret)
		return ret;

		data->hwmon_dev = hwmon_device_register(&client->dev);
		if (IS_ERR(data->hwmon_dev)) {
		ret = PTR_ERR(data->hwmon_dev);
		goto out_err_hwmon;
		}

		return 0;

		out_err_hwmon:
		sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
		return ret;
		}

		static int ina2xx_remove(struct i2c_client *client)
		{
		struct ina2xx_data *data = i2c_get_clientdata(client);

		hwmon_device_unregister(data->hwmon_dev);
		sysfs_remove_group(&client->dev.kobj, &ina2xx_group);

		return 0;
		}

		static const struct i2c_device_id ina2xx_id[] = {
		{ "ina219", ina219 },
		{ "ina226", ina226 },
		{ }
		};
		MODULE_DEVICE_TABLE(i2c, ina2xx_id);

		static struct i2c_driver ina2xx_driver = {
		.driver = {
		.name = "ina2xx",
		},
		.probe = ina2xx_probe,
		.remove = ina2xx_remove,
		.id_table = ina2xx_id,
		};

		static int __init ina2xx_init(void)
		{
		return i2c_add_driver(&ina2xx_driver);
		}

		static void __exit ina2xx_exit(void)
		{
		i2c_del_driver(&ina2xx_driver);
		}

		MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
		MODULE_DESCRIPTION("ina2xx driver");
		MODULE_LICENSE("GPL");

		module_init(ina2xx_init);
		module_exit(ina2xx_exit);

include/linux/platform_data/ina2xx.h

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		/*
		* Driver for Texas Instruments INA219, INA226 power monitor chips
		*
		* Copyright (C) 2012 Lothar Felten <l-felten@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.
		*
		* For further information, see the Documentation/hwmon/ina2xx file.
		*/

		/**
		* struct ina2xx_platform_data - ina2xx info
		* @shunt_uohms shunt resistance in microohms
		*/
		struct ina2xx_platform_data {
		long shunt_uohms;
		};