drivers/hwmon/ina2xx.c - kernel/common - Git at Google

 /*
  * 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
  *
  * INA220:
  * Bi-Directional Current/Power Monitor with I2C Interface
  * Datasheet: http://www.ti.com/product/ina220
  *
  * INA226:
  * Bi-Directional Current/Power Monitor with I2C Interface
  * Datasheet: http://www.ti.com/product/ina226
  *
  * INA230:
  * Bi-directional Current/Power Monitor with I2C Interface
  * Datasheet: http://www.ti.com/product/ina230
  *
  * Copyright (C) 2012 Lothar Felten <[email protected]>
  * 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/jiffies.h>
 #include <linux/of.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_config {
 	u16 config_default;
 	int calibration_factor;
 	int registers;
 	int shunt_div;
 	int bus_voltage_shift;
 	int bus_voltage_lsb;	/* uV */
 	int power_lsb;		/* uW */
 };

 struct ina2xx_data {
 	struct device *hwmon_dev;
 	const struct ina2xx_config *config;

 	struct mutex update_lock;
 	bool valid;
 	unsigned long last_updated;

 	int kind;
 	u16 regs[INA2XX_MAX_REGISTERS];
 };

 static const struct ina2xx_config ina2xx_config[] = {
 	[ina219] = {
 		.config_default = INA219_CONFIG_DEFAULT,
 		.calibration_factor = 40960000,
 		.registers = INA219_REGISTERS,
 		.shunt_div = 100,
 		.bus_voltage_shift = 3,
 		.bus_voltage_lsb = 4000,
 		.power_lsb = 20000,
 	},
 	[ina226] = {
 		.config_default = INA226_CONFIG_DEFAULT,
 		.calibration_factor = 5120000,
 		.registers = INA226_REGISTERS,
 		.shunt_div = 400,
 		.bus_voltage_shift = 0,
 		.bus_voltage_lsb = 1250,
 		.power_lsb = 25000,
 	},
 };

 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->config->registers; i++) {
 			int rv = i2c_smbus_read_word_swapped(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 ina2xx_get_value(struct ina2xx_data *data, u8 reg)
 {
 	int val;

 	switch (reg) {
 	case INA2XX_SHUNT_VOLTAGE:
 		val = DIV_ROUND_CLOSEST(data->regs[reg],
 					data->config->shunt_div);
 		break;
 	case INA2XX_BUS_VOLTAGE:
 		val = (data->regs[reg] >> data->config->bus_voltage_shift)
 		  * data->config->bus_voltage_lsb;
 		val = DIV_ROUND_CLOSEST(val, 1000);
 		break;
 	case INA2XX_POWER:
 		val = data->regs[reg] * data->config->power_lsb;
 		break;
 	case INA2XX_CURRENT:
 		/* LSB=1mA (selected). Is in mA */
 		val = data->regs[reg];
 		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);

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

 	return snprintf(buf, PAGE_SIZE, "%d\n",
 			ina2xx_get_value(data, attr->index));
 }

 /* 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;
 	u32 val;
 	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;
 	} else if (!of_property_read_u32(client->dev.of_node,
 				"shunt-resistor", &val)) {
 			shunt = val;
 	}

 	if (shunt <= 0)
 		return -ENODEV;

 	/* set the device type */
 	data->kind = id->driver_data;
 	data->config = &ina2xx_config[data->kind];

 	/* device configuration */
 	i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
 				     data->config->config_default);
 	/* set current LSB to 1mA, shunt is in uOhms */
 	/* (equation 13 in datasheet) */
 	i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION,
 				     data->config->calibration_factor / shunt);

 	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;
 	}

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

 	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 },
 	{ "ina220", ina219 },
 	{ "ina226", ina226 },
 	{ "ina230", 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,
 };

 module_i2c_driver(ina2xx_driver);

 MODULE_AUTHOR("Lothar Felten <[email protected]>");
 MODULE_DESCRIPTION("ina2xx driver");
 MODULE_LICENSE("GPL");
	/*
	* 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
	*
	* INA220:
	* Bi-Directional Current/Power Monitor with I2C Interface
	* Datasheet: http://www.ti.com/product/ina220
	*
	* INA226:
	* Bi-Directional Current/Power Monitor with I2C Interface
	* Datasheet: http://www.ti.com/product/ina226
	*
	* INA230:
	* Bi-directional Current/Power Monitor with I2C Interface
	* Datasheet: http://www.ti.com/product/ina230
	*
	* Copyright (C) 2012 Lothar Felten <[email protected]>
	* 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/jiffies.h>
	#include <linux/of.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_config {
	u16 config_default;
	int calibration_factor;
	int registers;
	int shunt_div;
	int bus_voltage_shift;
	int bus_voltage_lsb; /* uV */
	int power_lsb; /* uW */
	};

	struct ina2xx_data {
	struct device *hwmon_dev;
	const struct ina2xx_config *config;

	struct mutex update_lock;
	bool valid;
	unsigned long last_updated;

	int kind;
	u16 regs[INA2XX_MAX_REGISTERS];
	};

	static const struct ina2xx_config ina2xx_config[] = {
	[ina219] = {
	.config_default = INA219_CONFIG_DEFAULT,
	.calibration_factor = 40960000,
	.registers = INA219_REGISTERS,
	.shunt_div = 100,
	.bus_voltage_shift = 3,
	.bus_voltage_lsb = 4000,
	.power_lsb = 20000,
	},
	[ina226] = {
	.config_default = INA226_CONFIG_DEFAULT,
	.calibration_factor = 5120000,
	.registers = INA226_REGISTERS,
	.shunt_div = 400,
	.bus_voltage_shift = 0,
	.bus_voltage_lsb = 1250,
	.power_lsb = 25000,
	},
	};

	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->config->registers; i++) {
	int rv = i2c_smbus_read_word_swapped(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 ina2xx_get_value(struct ina2xx_data *data, u8 reg)
	{
	int val;

	switch (reg) {
	case INA2XX_SHUNT_VOLTAGE:
	val = DIV_ROUND_CLOSEST(data->regs[reg],
	data->config->shunt_div);
	break;
	case INA2XX_BUS_VOLTAGE:
	val = (data->regs[reg] >> data->config->bus_voltage_shift)
	* data->config->bus_voltage_lsb;
	val = DIV_ROUND_CLOSEST(val, 1000);
	break;
	case INA2XX_POWER:
	val = data->regs[reg] * data->config->power_lsb;
	break;
	case INA2XX_CURRENT:
	/* LSB=1mA (selected). Is in mA */
	val = data->regs[reg];
	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);

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

	return snprintf(buf, PAGE_SIZE, "%d\n",
	ina2xx_get_value(data, attr->index));
	}

	/* 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;
	u32 val;
	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;
	} else if (!of_property_read_u32(client->dev.of_node,
	"shunt-resistor", &val)) {
	shunt = val;
	}

	if (shunt <= 0)
	return -ENODEV;

	/* set the device type */
	data->kind = id->driver_data;
	data->config = &ina2xx_config[data->kind];

	/* device configuration */
	i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
	data->config->config_default);
	/* set current LSB to 1mA, shunt is in uOhms */
	/* (equation 13 in datasheet) */
	i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION,
	data->config->calibration_factor / shunt);

	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;
	}

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

	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 },
	{ "ina220", ina219 },
	{ "ina226", ina226 },
	{ "ina230", 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,
	};

	module_i2c_driver(ina2xx_driver);

	MODULE_AUTHOR("Lothar Felten <[email protected]>");
	MODULE_DESCRIPTION("ina2xx driver");
	MODULE_LICENSE("GPL");