[deliverable/linux.git] / drivers / hwmon / ina2xx.c

/*
 * 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 <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/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 i2c_client *client;
	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 ina2xx_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->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:
		/* signed register */
		val = DIV_ROUND_CLOSEST((s16)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:
		/* signed register, LSB=1mA (selected), in mA */
		val = (s16)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_attrs[] = {
	&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,
};
ATTRIBUTE_GROUPS(ina2xx);

static int ina2xx_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct i2c_adapter *adapter = client->adapter;
	struct ina2xx_platform_data *pdata;
	struct device *dev = &client->dev;
	struct ina2xx_data *data;
	struct device *hwmon_dev;
	long shunt = 10000; /* default shunt value 10mOhms */
	u32 val;

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

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

	if (dev_get_platdata(dev)) {
		pdata = dev_get_platdata(dev);
		shunt = pdata->shunt_uohms;
	} else if (!of_property_read_u32(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);

	data->client = client;
	mutex_init(&data->update_lock);

	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
							   data, ina2xx_groups);
	if (IS_ERR(hwmon_dev))
		return PTR_ERR(hwmon_dev);

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

	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,
	.id_table	= ina2xx_id,
};

module_i2c_driver(ina2xx_driver);

MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
MODULE_DESCRIPTION("ina2xx driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
f7c2fe38 FL	1	/*
	2	* Driver for Texas Instruments INA219, INA226 power monitor chips
	3	*
	4	* INA219:
	5	* Zero Drift Bi-Directional Current/Power Monitor with I2C Interface
	6	* Datasheet: http://www.ti.com/product/ina219
	7	*
dc92cd0c GR	8	* INA220:
	9	* Bi-Directional Current/Power Monitor with I2C Interface
	10	* Datasheet: http://www.ti.com/product/ina220
	11	*
f7c2fe38 FL	12	* INA226:
	13	* Bi-Directional Current/Power Monitor with I2C Interface
	14	* Datasheet: http://www.ti.com/product/ina226
	15	*
dc92cd0c GR	16	* INA230:
	17	* Bi-directional Current/Power Monitor with I2C Interface
	18	* Datasheet: http://www.ti.com/product/ina230
	19	*
f7c2fe38 FL	20	* Copyright (C) 2012 Lothar Felten <l-felten@ti.com>
	21	* Thanks to Jan Volkering
	22	*
	23	* This program is free software; you can redistribute it and/or modify
	24	* it under the terms of the GNU General Public License as published by
	25	* the Free Software Foundation; version 2 of the License.
	26	*/
	27
	28	#include <linux/kernel.h>
	29	#include <linux/module.h>
	30	#include <linux/init.h>
	31	#include <linux/err.h>
	32	#include <linux/slab.h>
	33	#include <linux/i2c.h>
	34	#include <linux/hwmon.h>
	35	#include <linux/hwmon-sysfs.h>
dcd8f392	36	#include <linux/jiffies.h>
31e7ad74	37	#include <linux/of.h>
f7c2fe38 FL	38
	39	#include <linux/platform_data/ina2xx.h>
	40
	41	/* common register definitions */
	42	#define INA2XX_CONFIG 0x00
	43	#define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */
	44	#define INA2XX_BUS_VOLTAGE 0x02 /* readonly */
	45	#define INA2XX_POWER 0x03 /* readonly */
	46	#define INA2XX_CURRENT 0x04 /* readonly */
	47	#define INA2XX_CALIBRATION 0x05
	48
	49	/* INA226 register definitions */
	50	#define INA226_MASK_ENABLE 0x06
	51	#define INA226_ALERT_LIMIT 0x07
	52	#define INA226_DIE_ID 0xFF
	53
	54
	55	/* register count */
	56	#define INA219_REGISTERS 6
	57	#define INA226_REGISTERS 8
	58
	59	#define INA2XX_MAX_REGISTERS 8
	60
	61	/* settings - depend on use case */
	62	#define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
	63	#define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */
	64
	65	/* worst case is 68.10 ms (~14.6Hz, ina219) */
	66	#define INA2XX_CONVERSION_RATE 15
	67
	68	enum ina2xx_ids { ina219, ina226 };
	69
6106db25 GR	70	struct ina2xx_config {
	71	u16 config_default;
	72	int calibration_factor;
	73	int registers;
	74	int shunt_div;
	75	int bus_voltage_shift;
	76	int bus_voltage_lsb; /* uV */
	77	int power_lsb; /* uW */
	78	};
	79
f7c2fe38	80	struct ina2xx_data {
468bf0e3	81	struct i2c_client *client;
6106db25	82	const struct ina2xx_config *config;
f7c2fe38 FL	83
	84	struct mutex update_lock;
	85	bool valid;
	86	unsigned long last_updated;
	87
	88	int kind;
f7c2fe38 FL	89	u16 regs[INA2XX_MAX_REGISTERS];
	90	};
	91
6106db25 GR	92	static const struct ina2xx_config ina2xx_config[] = {
	93	[ina219] = {
	94	.config_default = INA219_CONFIG_DEFAULT,
	95	.calibration_factor = 40960000,
	96	.registers = INA219_REGISTERS,
	97	.shunt_div = 100,
	98	.bus_voltage_shift = 3,
	99	.bus_voltage_lsb = 4000,
	100	.power_lsb = 20000,
	101	},
	102	[ina226] = {
	103	.config_default = INA226_CONFIG_DEFAULT,
	104	.calibration_factor = 5120000,
	105	.registers = INA226_REGISTERS,
	106	.shunt_div = 400,
	107	.bus_voltage_shift = 0,
	108	.bus_voltage_lsb = 1250,
	109	.power_lsb = 25000,
	110	},
	111	};
	112
f7c2fe38 FL	113	static struct ina2xx_data ina2xx_update_device(struct device dev)
f7c2fe38 FL	114	{
468bf0e3 GR	115	struct ina2xx_data *data = dev_get_drvdata(dev);
468bf0e3 GR	116	struct i2c_client *client = data->client;
f7c2fe38 FL	117	struct ina2xx_data *ret = data;
	118
	119	mutex_lock(&data->update_lock);
	120
	121	if (time_after(jiffies, data->last_updated +
	122	HZ / INA2XX_CONVERSION_RATE) \|\| !data->valid) {
	123
	124	int i;
	125
	126	dev_dbg(&client->dev, "Starting ina2xx update\n");
	127
	128	/* Read all registers */
6106db25	129	for (i = 0; i < data->config->registers; i++) {
080b98e9	130	int rv = i2c_smbus_read_word_swapped(client, i);
f7c2fe38 FL	131	if (rv < 0) {
	132	ret = ERR_PTR(rv);
	133	goto abort;
	134	}
	135	data->regs[i] = rv;
	136	}
	137	data->last_updated = jiffies;
	138	data->valid = 1;
	139	}
	140	abort:
	141	mutex_unlock(&data->update_lock);
	142	return ret;
	143	}
	144
6106db25	145	static int ina2xx_get_value(struct ina2xx_data *data, u8 reg)
f7c2fe38	146	{
6106db25	147	int val;
f7c2fe38 FL	148
	149	switch (reg) {
	150	case INA2XX_SHUNT_VOLTAGE:
c0214f98 FB	151	/* signed register */
c0214f98 FB	152	val = DIV_ROUND_CLOSEST((s16)data->regs[reg],
6106db25	153	data->config->shunt_div);
f7c2fe38 FL	154	break;
f7c2fe38 FL	155	case INA2XX_BUS_VOLTAGE:
6106db25 GR	156	val = (data->regs[reg] >> data->config->bus_voltage_shift)
	157	* data->config->bus_voltage_lsb;
	158	val = DIV_ROUND_CLOSEST(val, 1000);
f7c2fe38 FL	159	break;
f7c2fe38 FL	160	case INA2XX_POWER:
6106db25	161	val = data->regs[reg] * data->config->power_lsb;
f7c2fe38 FL	162	break;
f7c2fe38 FL	163	case INA2XX_CURRENT:
c0214f98 FB	164	/* signed register, LSB=1mA (selected), in mA */
c0214f98 FB	165	val = (s16)data->regs[reg];
f7c2fe38 FL	166	break;
	167	default:
	168	/* programmer goofed */
	169	WARN_ON_ONCE(1);
	170	val = 0;
	171	break;
	172	}
	173
	174	return val;
	175	}
	176
	177	static ssize_t ina2xx_show_value(struct device *dev,
	178	struct device_attribute da, char buf)
	179	{
	180	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	181	struct ina2xx_data *data = ina2xx_update_device(dev);
f7c2fe38 FL	182
	183	if (IS_ERR(data))
	184	return PTR_ERR(data);
	185
6106db25 GR	186	return snprintf(buf, PAGE_SIZE, "%d\n",
6106db25 GR	187	ina2xx_get_value(data, attr->index));
f7c2fe38 FL	188	}
	189
	190	/* shunt voltage */
f0df0fd9 GR	191	static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
f0df0fd9 GR	192	INA2XX_SHUNT_VOLTAGE);
f7c2fe38 FL	193
f7c2fe38 FL	194	/* bus voltage */
f0df0fd9 GR	195	static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina2xx_show_value, NULL,
f0df0fd9 GR	196	INA2XX_BUS_VOLTAGE);
f7c2fe38 FL	197
f7c2fe38 FL	198	/* calculated current */
f0df0fd9 GR	199	static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina2xx_show_value, NULL,
f0df0fd9 GR	200	INA2XX_CURRENT);
f7c2fe38 FL	201
f7c2fe38 FL	202	/* calculated power */
f0df0fd9 GR	203	static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina2xx_show_value, NULL,
f0df0fd9 GR	204	INA2XX_POWER);
f7c2fe38 FL	205
f7c2fe38 FL	206	/* pointers to created device attributes */
468bf0e3	207	static struct attribute *ina2xx_attrs[] = {
f7c2fe38 FL	208	&sensor_dev_attr_in0_input.dev_attr.attr,
	209	&sensor_dev_attr_in1_input.dev_attr.attr,
	210	&sensor_dev_attr_curr1_input.dev_attr.attr,
	211	&sensor_dev_attr_power1_input.dev_attr.attr,
	212	NULL,
	213	};
468bf0e3	214	ATTRIBUTE_GROUPS(ina2xx);
f7c2fe38 FL	215
	216	static int ina2xx_probe(struct i2c_client *client,
	217	const struct i2c_device_id *id)
	218	{
	219	struct i2c_adapter *adapter = client->adapter;
f7c2fe38	220	struct ina2xx_platform_data *pdata;
468bf0e3 GR	221	struct device *dev = &client->dev;
	222	struct ina2xx_data *data;
	223	struct device *hwmon_dev;
f7c2fe38	224	long shunt = 10000; /* default shunt value 10mOhms */
468bf0e3	225	u32 val;
f7c2fe38 FL	226
	227	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
	228	return -ENODEV;
	229
468bf0e3	230	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
f7c2fe38 FL	231	if (!data)
	232	return -ENOMEM;
	233
468bf0e3 GR	234	if (dev_get_platdata(dev)) {
468bf0e3 GR	235	pdata = dev_get_platdata(dev);
f7c2fe38	236	shunt = pdata->shunt_uohms;
468bf0e3 GR	237	} else if (!of_property_read_u32(dev->of_node,
	238	"shunt-resistor", &val)) {
	239	shunt = val;
f7c2fe38 FL	240	}
	241
	242	if (shunt <= 0)
	243	return -ENODEV;
	244
	245	/* set the device type */
	246	data->kind = id->driver_data;
6106db25	247	data->config = &ina2xx_config[data->kind];
f7c2fe38	248
6106db25 GR	249	/* device configuration */
	250	i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
	251	data->config->config_default);
	252	/* set current LSB to 1mA, shunt is in uOhms */
	253	/* (equation 13 in datasheet) */
	254	i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION,
	255	data->config->calibration_factor / shunt);
f7c2fe38	256
468bf0e3	257	data->client = client;
f7c2fe38 FL	258	mutex_init(&data->update_lock);
f7c2fe38 FL	259
468bf0e3 GR	260	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
	261	data, ina2xx_groups);
	262	if (IS_ERR(hwmon_dev))
	263	return PTR_ERR(hwmon_dev);
f7c2fe38	264
468bf0e3	265	dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n",
6106db25 GR	266	id->name, shunt);
6106db25 GR	267
f7c2fe38	268	return 0;
f7c2fe38 FL	269	}
	270
	271	static const struct i2c_device_id ina2xx_id[] = {
	272	{ "ina219", ina219 },
dc92cd0c	273	{ "ina220", ina219 },
f7c2fe38	274	{ "ina226", ina226 },
dc92cd0c	275	{ "ina230", ina226 },
f7c2fe38 FL	276	{ }
	277	};
	278	MODULE_DEVICE_TABLE(i2c, ina2xx_id);
	279
	280	static struct i2c_driver ina2xx_driver = {
	281	.driver = {
	282	.name = "ina2xx",
	283	},
	284	.probe = ina2xx_probe,
f7c2fe38 FL	285	.id_table = ina2xx_id,
	286	};
	287
d835ca0f	288	module_i2c_driver(ina2xx_driver);
f7c2fe38 FL	289
	290	MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
	291	MODULE_DESCRIPTION("ina2xx driver");
	292	MODULE_LICENSE("GPL");