[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 <[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_device.h>
#include <linux/of.h>
#include <linux/delay.h>
#include <linux/util_macros.h>
#include <linux/regmap.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
#define INA2XX_MAX_DELAY		69 /* worst case delay in ms */

#define INA2XX_RSHUNT_DEFAULT		10000

/* bit mask for reading the averaging setting in the configuration register */
#define INA226_AVG_RD_MASK		0x0E00

#define INA226_READ_AVG(reg)		(((reg) & INA226_AVG_RD_MASK) >> 9)
#define INA226_SHIFT_AVG(val)		((val) << 9)

/* common attrs, ina226 attrs and NULL */
#define INA2XX_MAX_ATTRIBUTE_GROUPS	3

/*
 * Both bus voltage and shunt voltage conversion times for ina226 are set
 * to 0b0100 on POR, which translates to 2200 microseconds in total.
 */
#define INA226_TOTAL_CONV_TIME_DEFAULT	2200

static struct regmap_config ina2xx_regmap_config = {
	.reg_bits = 8,
	.val_bits = 16,
};

enum ina2xx_ids { ina219, ina226 };

struct ina2xx_config {
	u16 config_default;
	int calibration_value;
	int registers;
	int shunt_div;
	int bus_voltage_shift;
	int bus_voltage_lsb;	/* uV */
	int power_lsb_factor;
};

struct ina2xx_data {
	const struct ina2xx_config *config;

	long rshunt;
	long current_lsb_uA;
	long power_lsb_uW;
	struct mutex config_lock;
	struct regmap *regmap;

	const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
};

static const struct ina2xx_config ina2xx_config[] = {
	[ina219] = {
		.config_default = INA219_CONFIG_DEFAULT,
		.calibration_value = 4096,
		.registers = INA219_REGISTERS,
		.shunt_div = 100,
		.bus_voltage_shift = 3,
		.bus_voltage_lsb = 4000,
		.power_lsb_factor = 20,
	},
	[ina226] = {
		.config_default = INA226_CONFIG_DEFAULT,
		.calibration_value = 2048,
		.registers = INA226_REGISTERS,
		.shunt_div = 400,
		.bus_voltage_shift = 0,
		.bus_voltage_lsb = 1250,
		.power_lsb_factor = 25,
	},
};

/*
 * Available averaging rates for ina226. The indices correspond with
 * the bit values expected by the chip (according to the ina226 datasheet,
 * table 3 AVG bit settings, found at
 * http://www.ti.com/lit/ds/symlink/ina226.pdf.
 */
static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };

static int ina226_reg_to_interval(u16 config)
{
	int avg = ina226_avg_tab[INA226_READ_AVG(config)];

	/*
	 * Multiply the total conversion time by the number of averages.
	 * Return the result in milliseconds.
	 */
	return DIV_ROUND_CLOSEST(avg * INA226_TOTAL_CONV_TIME_DEFAULT, 1000);
}

/*
 * Return the new, shifted AVG field value of CONFIG register,
 * to use with regmap_update_bits
 */
static u16 ina226_interval_to_reg(int interval)
{
	int avg, avg_bits;

	avg = DIV_ROUND_CLOSEST(interval * 1000,
				INA226_TOTAL_CONV_TIME_DEFAULT);
	avg_bits = find_closest(avg, ina226_avg_tab,
				ARRAY_SIZE(ina226_avg_tab));

	return INA226_SHIFT_AVG(avg_bits);
}

/*
 * Calibration register is set to the best value, which eliminates
 * truncation errors on calculating current register in hardware.
 * According to datasheet (eq. 3) the best values are 2048 for
 * ina226 and 4096 for ina219. They are hardcoded as calibration_value.
 */
static int ina2xx_calibrate(struct ina2xx_data *data)
{
	return regmap_write(data->regmap, INA2XX_CALIBRATION,
			    data->config->calibration_value);
}

/*
 * Initialize the configuration and calibration registers.
 */
static int ina2xx_init(struct ina2xx_data *data)
{
	int ret = regmap_write(data->regmap, INA2XX_CONFIG,
			       data->config->config_default);
	if (ret < 0)
		return ret;

	return ina2xx_calibrate(data);
}

static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
{
	struct ina2xx_data *data = dev_get_drvdata(dev);
	int ret, retry;

	dev_dbg(dev, "Starting register %d read\n", reg);

	for (retry = 5; retry; retry--) {

		ret = regmap_read(data->regmap, reg, regval);
		if (ret < 0)
			return ret;

		dev_dbg(dev, "read %d, val = 0x%04x\n", reg, *regval);

		/*
		 * If the current value in the calibration register is 0, the
		 * power and current registers will also remain at 0. In case
		 * the chip has been reset let's check the calibration
		 * register and reinitialize if needed.
		 * We do that extra read of the calibration register if there
		 * is some hint of a chip reset.
		 */
		if (*regval == 0) {
			unsigned int cal;

			ret = regmap_read(data->regmap, INA2XX_CALIBRATION,
					  &cal);
			if (ret < 0)
				return ret;

			if (cal == 0) {
				dev_warn(dev, "chip not calibrated, reinitializing\n");

				ret = ina2xx_init(data);
				if (ret < 0)
					return ret;
				/*
				 * Let's make sure the power and current
				 * registers have been updated before trying
				 * again.
				 */
				msleep(INA2XX_MAX_DELAY);
				continue;
			}
		}
		return 0;
	}

	/*
	 * If we're here then although all write operations succeeded, the
	 * chip still returns 0 in the calibration register. Nothing more we
	 * can do here.
	 */
	dev_err(dev, "unable to reinitialize the chip\n");
	return -ENODEV;
}

static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
			    unsigned int regval)
{
	int val;

	switch (reg) {
	case INA2XX_SHUNT_VOLTAGE:
		/* signed register */
		val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div);
		break;
	case INA2XX_BUS_VOLTAGE:
		val = (regval >> data->config->bus_voltage_shift)
		  * data->config->bus_voltage_lsb;
		val = DIV_ROUND_CLOSEST(val, 1000);
		break;
	case INA2XX_POWER:
		val = regval * data->power_lsb_uW;
		break;
	case INA2XX_CURRENT:
		/* signed register, result in mA */
		val = (s16)regval * data->current_lsb_uA;
		val = DIV_ROUND_CLOSEST(val, 1000);
		break;
	case INA2XX_CALIBRATION:
		val = regval;
		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 = dev_get_drvdata(dev);
	unsigned int regval;

	int err = ina2xx_read_reg(dev, attr->index, &regval);

	if (err < 0)
		return err;

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

/*
 * In order to keep calibration register value fixed, the product
 * of current_lsb and shunt_resistor should also be fixed and equal
 * to shunt_voltage_lsb = 1 / shunt_div multiplied by 10^9 in order
 * to keep the scale.
 */
static int ina2xx_set_shunt(struct ina2xx_data *data, long val)
{
	unsigned int dividend = DIV_ROUND_CLOSEST(1000000000,
						  data->config->shunt_div);
	if (val <= 0 || val > dividend)
		return -EINVAL;

	mutex_lock(&data->config_lock);
	data->rshunt = val;
	data->current_lsb_uA = DIV_ROUND_CLOSEST(dividend, val);
	data->power_lsb_uW = data->config->power_lsb_factor *
			     data->current_lsb_uA;
	mutex_unlock(&data->config_lock);

	return 0;
}

static ssize_t ina2xx_show_shunt(struct device *dev,
			      struct device_attribute *da,
			      char *buf)
{
	struct ina2xx_data *data = dev_get_drvdata(dev);

	return snprintf(buf, PAGE_SIZE, "%li\n", data->rshunt);
}

static ssize_t ina2xx_store_shunt(struct device *dev,
				  struct device_attribute *da,
				  const char *buf, size_t count)
{
	unsigned long val;
	int status;
	struct ina2xx_data *data = dev_get_drvdata(dev);

	status = kstrtoul(buf, 10, &val);
	if (status < 0)
		return status;

	status = ina2xx_set_shunt(data, val);
	if (status < 0)
		return status;
	return count;
}

static ssize_t ina226_set_interval(struct device *dev,
				   struct device_attribute *da,
				   const char *buf, size_t count)
{
	struct ina2xx_data *data = dev_get_drvdata(dev);
	unsigned long val;
	int status;

	status = kstrtoul(buf, 10, &val);
	if (status < 0)
		return status;

	if (val > INT_MAX || val == 0)
		return -EINVAL;

	status = regmap_update_bits(data->regmap, INA2XX_CONFIG,
				    INA226_AVG_RD_MASK,
				    ina226_interval_to_reg(val));
	if (status < 0)
		return status;

	return count;
}

static ssize_t ina226_show_interval(struct device *dev,
				    struct device_attribute *da, char *buf)
{
	struct ina2xx_data *data = dev_get_drvdata(dev);
	int status;
	unsigned int regval;

	status = regmap_read(data->regmap, INA2XX_CONFIG, &regval);
	if (status)
		return status;

	return snprintf(buf, PAGE_SIZE, "%d\n", ina226_reg_to_interval(regval));
}

/* 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);

/* shunt resistance */
static SENSOR_DEVICE_ATTR(shunt_resistor, S_IRUGO | S_IWUSR,
			  ina2xx_show_shunt, ina2xx_store_shunt,
			  INA2XX_CALIBRATION);

/* update interval (ina226 only) */
static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR,
			  ina226_show_interval, ina226_set_interval, 0);

/* 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,
	&sensor_dev_attr_shunt_resistor.dev_attr.attr,
	NULL,
};

static const struct attribute_group ina2xx_group = {
	.attrs = ina2xx_attrs,
};

static struct attribute *ina226_attrs[] = {
	&sensor_dev_attr_update_interval.dev_attr.attr,
	NULL,
};

static const struct attribute_group ina226_group = {
	.attrs = ina226_attrs,
};

static int ina2xx_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct ina2xx_data *data;
	struct device *hwmon_dev;
	u32 val;
	int ret, group = 0;
	enum ina2xx_ids chip;

	if (client->dev.of_node)
		chip = (enum ina2xx_ids)of_device_get_match_data(&client->dev);
	else
		chip = id->driver_data;

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

	/* set the device type */
	data->config = &ina2xx_config[chip];
	mutex_init(&data->config_lock);

	if (of_property_read_u32(dev->of_node, "shunt-resistor", &val) < 0) {
		struct ina2xx_platform_data *pdata = dev_get_platdata(dev);

		if (pdata)
			val = pdata->shunt_uohms;
		else
			val = INA2XX_RSHUNT_DEFAULT;
	}

	ina2xx_set_shunt(data, val);

	ina2xx_regmap_config.max_register = data->config->registers;

	data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
	if (IS_ERR(data->regmap)) {
		dev_err(dev, "failed to allocate register map\n");
		return PTR_ERR(data->regmap);
	}

	ret = ina2xx_init(data);
	if (ret < 0) {
		dev_err(dev, "error configuring the device: %d\n", ret);
		return -ENODEV;
	}

	data->groups[group++] = &ina2xx_group;
	if (chip == ina226)
		data->groups[group++] = &ina226_group;

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

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

	return 0;
}

static const struct i2c_device_id ina2xx_id[] = {
	{ "ina219", ina219 },
	{ "ina220", ina219 },
	{ "ina226", ina226 },
	{ "ina230", ina226 },
	{ "ina231", ina226 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ina2xx_id);

static const struct of_device_id ina2xx_of_match[] = {
	{
		.compatible = "ti,ina219",
		.data = (void *)ina219
	},
	{
		.compatible = "ti,ina220",
		.data = (void *)ina219
	},
	{
		.compatible = "ti,ina226",
		.data = (void *)ina226
	},
	{
		.compatible = "ti,ina230",
		.data = (void *)ina226
	},
	{
		.compatible = "ti,ina231",
		.data = (void *)ina226
	},
	{ },
};
MODULE_DEVICE_TABLE(of, ina2xx_of_match);

static struct i2c_driver ina2xx_driver = {
	.driver = {
		.name	= "ina2xx",
		.of_match_table = of_match_ptr(ina2xx_of_match),
	},
	.probe		= ina2xx_probe,
	.id_table	= ina2xx_id,
};

module_i2c_driver(ina2xx_driver);

MODULE_AUTHOR("Lothar Felten <[email protected]>");
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	*
3ad86700	20	* Copyright (C) 2012 Lothar Felten <[email protected]>
f7c2fe38 FL	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>
bd0ddd4d	37	#include <linux/of_device.h>
31e7ad74	38	#include <linux/of.h>
509416a8	39	#include <linux/delay.h>
d38df34e	40	#include <linux/util_macros.h>
a0de56c8	41	#include <linux/regmap.h>
f7c2fe38 FL	42
	43	#include <linux/platform_data/ina2xx.h>
	44
	45	/* common register definitions */
	46	#define INA2XX_CONFIG 0x00
	47	#define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */
	48	#define INA2XX_BUS_VOLTAGE 0x02 /* readonly */
	49	#define INA2XX_POWER 0x03 /* readonly */
	50	#define INA2XX_CURRENT 0x04 /* readonly */
	51	#define INA2XX_CALIBRATION 0x05
	52
	53	/* INA226 register definitions */
	54	#define INA226_MASK_ENABLE 0x06
	55	#define INA226_ALERT_LIMIT 0x07
	56	#define INA226_DIE_ID 0xFF
	57
f7c2fe38 FL	58	/* register count */
	59	#define INA219_REGISTERS 6
	60	#define INA226_REGISTERS 8
	61
	62	#define INA2XX_MAX_REGISTERS 8
	63
	64	/* settings - depend on use case */
	65	#define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
	66	#define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */
	67
	68	/* worst case is 68.10 ms (~14.6Hz, ina219) */
	69	#define INA2XX_CONVERSION_RATE 15
509416a8 BG	70	#define INA2XX_MAX_DELAY 69 /* worst case delay in ms */
	71
	72	#define INA2XX_RSHUNT_DEFAULT 10000
f7c2fe38	73
72a87a47 BG	74	/* bit mask for reading the averaging setting in the configuration register */
	75	#define INA226_AVG_RD_MASK 0x0E00
	76
	77	#define INA226_READ_AVG(reg) (((reg) & INA226_AVG_RD_MASK) >> 9)
	78	#define INA226_SHIFT_AVG(val) ((val) << 9)
	79
	80	/* common attrs, ina226 attrs and NULL */
	81	#define INA2XX_MAX_ATTRIBUTE_GROUPS 3
	82
	83	/*
	84	* Both bus voltage and shunt voltage conversion times for ina226 are set
	85	* to 0b0100 on POR, which translates to 2200 microseconds in total.
	86	*/
	87	#define INA226_TOTAL_CONV_TIME_DEFAULT 2200
	88
a0de56c8 MT	89	static struct regmap_config ina2xx_regmap_config = {
	90	.reg_bits = 8,
	91	.val_bits = 16,
	92	};
	93
f7c2fe38 FL	94	enum ina2xx_ids { ina219, ina226 };
f7c2fe38 FL	95
6106db25 GR	96	struct ina2xx_config {
6106db25 GR	97	u16 config_default;
5d389b12	98	int calibration_value;
6106db25 GR	99	int registers;
	100	int shunt_div;
	101	int bus_voltage_shift;
	102	int bus_voltage_lsb; /* uV */
5d389b12	103	int power_lsb_factor;
6106db25 GR	104	};
6106db25 GR	105
f7c2fe38	106	struct ina2xx_data {
6106db25	107	const struct ina2xx_config *config;
f7c2fe38	108
509416a8	109	long rshunt;
5d389b12 MP	110	long current_lsb_uA;
5d389b12 MP	111	long power_lsb_uW;
a0de56c8 MT	112	struct mutex config_lock;
a0de56c8 MT	113	struct regmap *regmap;
f7c2fe38	114
72a87a47	115	const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
f7c2fe38 FL	116	};
f7c2fe38 FL	117
6106db25 GR	118	static const struct ina2xx_config ina2xx_config[] = {
	119	[ina219] = {
	120	.config_default = INA219_CONFIG_DEFAULT,
5d389b12	121	.calibration_value = 4096,
6106db25 GR	122	.registers = INA219_REGISTERS,
	123	.shunt_div = 100,
	124	.bus_voltage_shift = 3,
	125	.bus_voltage_lsb = 4000,
5d389b12	126	.power_lsb_factor = 20,
6106db25 GR	127	},
	128	[ina226] = {
	129	.config_default = INA226_CONFIG_DEFAULT,
5d389b12	130	.calibration_value = 2048,
6106db25 GR	131	.registers = INA226_REGISTERS,
	132	.shunt_div = 400,
	133	.bus_voltage_shift = 0,
	134	.bus_voltage_lsb = 1250,
5d389b12	135	.power_lsb_factor = 25,
6106db25 GR	136	},
	137	};
	138
72a87a47 BG	139	/*
	140	* Available averaging rates for ina226. The indices correspond with
	141	* the bit values expected by the chip (according to the ina226 datasheet,
	142	* table 3 AVG bit settings, found at
	143	* http://www.ti.com/lit/ds/symlink/ina226.pdf.
	144	*/
	145	static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
	146
72a87a47 BG	147	static int ina226_reg_to_interval(u16 config)
	148	{
	149	int avg = ina226_avg_tab[INA226_READ_AVG(config)];
	150
	151	/*
	152	* Multiply the total conversion time by the number of averages.
	153	* Return the result in milliseconds.
	154	*/
	155	return DIV_ROUND_CLOSEST(avg * INA226_TOTAL_CONV_TIME_DEFAULT, 1000);
	156	}
	157
a0de56c8 MT	158	/*
	159	* Return the new, shifted AVG field value of CONFIG register,
	160	* to use with regmap_update_bits
	161	*/
	162	static u16 ina226_interval_to_reg(int interval)
72a87a47 BG	163	{
	164	int avg, avg_bits;
	165
	166	avg = DIV_ROUND_CLOSEST(interval * 1000,
	167	INA226_TOTAL_CONV_TIME_DEFAULT);
d38df34e BG	168	avg_bits = find_closest(avg, ina226_avg_tab,
d38df34e BG	169	ARRAY_SIZE(ina226_avg_tab));
72a87a47	170
a0de56c8	171	return INA226_SHIFT_AVG(avg_bits);
72a87a47 BG	172	}
72a87a47 BG	173
5d389b12 MP	174	/*
	175	* Calibration register is set to the best value, which eliminates
	176	* truncation errors on calculating current register in hardware.
	177	* According to datasheet (eq. 3) the best values are 2048 for
	178	* ina226 and 4096 for ina219. They are hardcoded as calibration_value.
	179	*/
8a5fc795 BG	180	static int ina2xx_calibrate(struct ina2xx_data *data)
8a5fc795 BG	181	{
5d389b12 MP	182	return regmap_write(data->regmap, INA2XX_CALIBRATION,
5d389b12 MP	183	data->config->calibration_value);
8a5fc795 BG	184	}
8a5fc795 BG	185
509416a8 BG	186	/*
	187	* Initialize the configuration and calibration registers.
	188	*/
	189	static int ina2xx_init(struct ina2xx_data *data)
f7c2fe38	190	{
a0de56c8 MT	191	int ret = regmap_write(data->regmap, INA2XX_CONFIG,
a0de56c8 MT	192	data->config->config_default);
509416a8 BG	193	if (ret < 0)
509416a8 BG	194	return ret;
f7c2fe38	195
8a5fc795	196	return ina2xx_calibrate(data);
509416a8	197	}
f7c2fe38	198
a0de56c8	199	static int ina2xx_read_reg(struct device dev, int reg, unsigned int regval)
509416a8 BG	200	{
509416a8 BG	201	struct ina2xx_data *data = dev_get_drvdata(dev);
a0de56c8	202	int ret, retry;
f7c2fe38	203
a0de56c8	204	dev_dbg(dev, "Starting register %d read\n", reg);
f7c2fe38	205
509416a8	206	for (retry = 5; retry; retry--) {
a0de56c8 MT	207
	208	ret = regmap_read(data->regmap, reg, regval);
	209	if (ret < 0)
	210	return ret;
	211
	212	dev_dbg(dev, "read %d, val = 0x%04x\n", reg, *regval);
509416a8 BG	213
	214	/*
	215	* If the current value in the calibration register is 0, the
	216	* power and current registers will also remain at 0. In case
	217	* the chip has been reset let's check the calibration
	218	* register and reinitialize if needed.
a0de56c8 MT	219	* We do that extra read of the calibration register if there
a0de56c8 MT	220	* is some hint of a chip reset.
509416a8	221	*/
a0de56c8 MT	222	if (*regval == 0) {
	223	unsigned int cal;
	224
	225	ret = regmap_read(data->regmap, INA2XX_CALIBRATION,
	226	&cal);
	227	if (ret < 0)
	228	return ret;
	229
	230	if (cal == 0) {
	231	dev_warn(dev, "chip not calibrated, reinitializing\n");
	232
	233	ret = ina2xx_init(data);
	234	if (ret < 0)
	235	return ret;
	236	/*
	237	* Let's make sure the power and current
	238	* registers have been updated before trying
	239	* again.
	240	*/
	241	msleep(INA2XX_MAX_DELAY);
	242	continue;
	243	}
509416a8	244	}
509416a8	245	return 0;
f7c2fe38	246	}
509416a8 BG	247
	248	/*
	249	* If we're here then although all write operations succeeded, the
	250	* chip still returns 0 in the calibration register. Nothing more we
	251	* can do here.
	252	*/
	253	dev_err(dev, "unable to reinitialize the chip\n");
	254	return -ENODEV;
	255	}
	256
a0de56c8 MT	257	static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
a0de56c8 MT	258	unsigned int regval)
f7c2fe38	259	{
6106db25	260	int val;
f7c2fe38 FL	261
	262	switch (reg) {
	263	case INA2XX_SHUNT_VOLTAGE:
c0214f98	264	/* signed register */
a0de56c8	265	val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div);
f7c2fe38 FL	266	break;
f7c2fe38 FL	267	case INA2XX_BUS_VOLTAGE:
a0de56c8	268	val = (regval >> data->config->bus_voltage_shift)
6106db25 GR	269	* data->config->bus_voltage_lsb;
6106db25 GR	270	val = DIV_ROUND_CLOSEST(val, 1000);
f7c2fe38 FL	271	break;
f7c2fe38 FL	272	case INA2XX_POWER:
5d389b12	273	val = regval * data->power_lsb_uW;
f7c2fe38 FL	274	break;
f7c2fe38 FL	275	case INA2XX_CURRENT:
5d389b12	276	/* signed register, result in mA */
38cd989e	277	val = (s16)regval * data->current_lsb_uA;
5d389b12	278	val = DIV_ROUND_CLOSEST(val, 1000);
f7c2fe38	279	break;
8a5fc795	280	case INA2XX_CALIBRATION:
5d389b12	281	val = regval;
8a5fc795	282	break;
f7c2fe38 FL	283	default:
	284	/* programmer goofed */
	285	WARN_ON_ONCE(1);
	286	val = 0;
	287	break;
	288	}
	289
	290	return val;
	291	}
	292
	293	static ssize_t ina2xx_show_value(struct device *dev,
	294	struct device_attribute da, char buf)
	295	{
	296	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
a0de56c8 MT	297	struct ina2xx_data *data = dev_get_drvdata(dev);
a0de56c8 MT	298	unsigned int regval;
f7c2fe38	299
a0de56c8 MT	300	int err = ina2xx_read_reg(dev, attr->index, &regval);
	301
	302	if (err < 0)
	303	return err;
f7c2fe38	304
6106db25	305	return snprintf(buf, PAGE_SIZE, "%d\n",
a0de56c8	306	ina2xx_get_value(data, attr->index, regval));
f7c2fe38 FL	307	}
f7c2fe38 FL	308
5d389b12 MP	309	/*
	310	* In order to keep calibration register value fixed, the product
	311	* of current_lsb and shunt_resistor should also be fixed and equal
	312	* to shunt_voltage_lsb = 1 / shunt_div multiplied by 10^9 in order
	313	* to keep the scale.
	314	*/
	315	static int ina2xx_set_shunt(struct ina2xx_data *data, long val)
	316	{
	317	unsigned int dividend = DIV_ROUND_CLOSEST(1000000000,
	318	data->config->shunt_div);
	319	if (val <= 0 \|\| val > dividend)
	320	return -EINVAL;
	321
	322	mutex_lock(&data->config_lock);
	323	data->rshunt = val;
	324	data->current_lsb_uA = DIV_ROUND_CLOSEST(dividend, val);
	325	data->power_lsb_uW = data->config->power_lsb_factor *
	326	data->current_lsb_uA;
	327	mutex_unlock(&data->config_lock);
	328
	329	return 0;
	330	}
	331
3ad86700 LF	332	static ssize_t ina2xx_show_shunt(struct device *dev,
	333	struct device_attribute *da,
	334	char *buf)
	335	{
	336	struct ina2xx_data *data = dev_get_drvdata(dev);
	337
	338	return snprintf(buf, PAGE_SIZE, "%li\n", data->rshunt);
	339	}
	340
5d389b12 MP	341	static ssize_t ina2xx_store_shunt(struct device *dev,
	342	struct device_attribute *da,
	343	const char *buf, size_t count)
8a5fc795	344	{
8a5fc795 BG	345	unsigned long val;
8a5fc795 BG	346	int status;
a0de56c8	347	struct ina2xx_data *data = dev_get_drvdata(dev);
8a5fc795 BG	348
	349	status = kstrtoul(buf, 10, &val);
	350	if (status < 0)
	351	return status;
	352
5d389b12	353	status = ina2xx_set_shunt(data, val);
8a5fc795 BG	354	if (status < 0)
8a5fc795 BG	355	return status;
8a5fc795 BG	356	return count;
	357	}
	358
72a87a47 BG	359	static ssize_t ina226_set_interval(struct device *dev,
	360	struct device_attribute *da,
	361	const char *buf, size_t count)
	362	{
	363	struct ina2xx_data *data = dev_get_drvdata(dev);
	364	unsigned long val;
	365	int status;
	366
72a87a47 BG	367	status = kstrtoul(buf, 10, &val);
	368	if (status < 0)
	369	return status;
	370
	371	if (val > INT_MAX \|\| val == 0)
	372	return -EINVAL;
	373
a0de56c8 MT	374	status = regmap_update_bits(data->regmap, INA2XX_CONFIG,
	375	INA226_AVG_RD_MASK,
	376	ina226_interval_to_reg(val));
72a87a47 BG	377	if (status < 0)
	378	return status;
	379
	380	return count;
	381	}
	382
	383	static ssize_t ina226_show_interval(struct device *dev,
	384	struct device_attribute da, char buf)
	385	{
a0de56c8 MT	386	struct ina2xx_data *data = dev_get_drvdata(dev);
	387	int status;
	388	unsigned int regval;
72a87a47	389
a0de56c8 MT	390	status = regmap_read(data->regmap, INA2XX_CONFIG, &regval);
	391	if (status)
	392	return status;
72a87a47	393
a0de56c8	394	return snprintf(buf, PAGE_SIZE, "%d\n", ina226_reg_to_interval(regval));
72a87a47 BG	395	}
72a87a47 BG	396
f7c2fe38	397	/* shunt voltage */
f0df0fd9 GR	398	static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
f0df0fd9 GR	399	INA2XX_SHUNT_VOLTAGE);
f7c2fe38 FL	400
f7c2fe38 FL	401	/* bus voltage */
f0df0fd9 GR	402	static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina2xx_show_value, NULL,
f0df0fd9 GR	403	INA2XX_BUS_VOLTAGE);
f7c2fe38 FL	404
f7c2fe38 FL	405	/* calculated current */
f0df0fd9 GR	406	static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina2xx_show_value, NULL,
f0df0fd9 GR	407	INA2XX_CURRENT);
f7c2fe38 FL	408
f7c2fe38 FL	409	/* calculated power */
f0df0fd9 GR	410	static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina2xx_show_value, NULL,
f0df0fd9 GR	411	INA2XX_POWER);
f7c2fe38	412
8a5fc795 BG	413	/* shunt resistance */
8a5fc795 BG	414	static SENSOR_DEVICE_ATTR(shunt_resistor, S_IRUGO \| S_IWUSR,
3ad86700	415	ina2xx_show_shunt, ina2xx_store_shunt,
8a5fc795 BG	416	INA2XX_CALIBRATION);
8a5fc795 BG	417
72a87a47 BG	418	/* update interval (ina226 only) */
	419	static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO \| S_IWUSR,
	420	ina226_show_interval, ina226_set_interval, 0);
	421
f7c2fe38	422	/* pointers to created device attributes */
468bf0e3	423	static struct attribute *ina2xx_attrs[] = {
f7c2fe38 FL	424	&sensor_dev_attr_in0_input.dev_attr.attr,
	425	&sensor_dev_attr_in1_input.dev_attr.attr,
	426	&sensor_dev_attr_curr1_input.dev_attr.attr,
	427	&sensor_dev_attr_power1_input.dev_attr.attr,
8a5fc795	428	&sensor_dev_attr_shunt_resistor.dev_attr.attr,
f7c2fe38 FL	429	NULL,
f7c2fe38 FL	430	};
72a87a47 BG	431
	432	static const struct attribute_group ina2xx_group = {
	433	.attrs = ina2xx_attrs,
	434	};
	435
	436	static struct attribute *ina226_attrs[] = {
	437	&sensor_dev_attr_update_interval.dev_attr.attr,
	438	NULL,
	439	};
	440
	441	static const struct attribute_group ina226_group = {
	442	.attrs = ina226_attrs,
	443	};
f7c2fe38 FL	444
	445	static int ina2xx_probe(struct i2c_client *client,
	446	const struct i2c_device_id *id)
	447	{
468bf0e3 GR	448	struct device *dev = &client->dev;
	449	struct ina2xx_data *data;
	450	struct device *hwmon_dev;
468bf0e3	451	u32 val;
72a87a47	452	int ret, group = 0;
bd0ddd4d JMC	453	enum ina2xx_ids chip;
	454
	455	if (client->dev.of_node)
	456	chip = (enum ina2xx_ids)of_device_get_match_data(&client->dev);
	457	else
	458	chip = id->driver_data;
f7c2fe38	459
468bf0e3	460	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
f7c2fe38 FL	461	if (!data)
	462	return -ENOMEM;
	463
f7c2fe38	464	/* set the device type */
bd0ddd4d	465	data->config = &ina2xx_config[chip];
0c4c5860	466	mutex_init(&data->config_lock);
72a87a47	467
001e2e73 MT	468	if (of_property_read_u32(dev->of_node, "shunt-resistor", &val) < 0) {
	469	struct ina2xx_platform_data *pdata = dev_get_platdata(dev);
	470
	471	if (pdata)
	472	val = pdata->shunt_uohms;
	473	else
	474	val = INA2XX_RSHUNT_DEFAULT;
	475	}
	476
5d389b12	477	ina2xx_set_shunt(data, val);
001e2e73	478
a0de56c8 MT	479	ina2xx_regmap_config.max_register = data->config->registers;
	480
	481	data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
	482	if (IS_ERR(data->regmap)) {
	483	dev_err(dev, "failed to allocate register map\n");
	484	return PTR_ERR(data->regmap);
	485	}
	486
509416a8	487	ret = ina2xx_init(data);
f975b339	488	if (ret < 0) {
509416a8	489	dev_err(dev, "error configuring the device: %d\n", ret);
f975b339 BG	490	return -ENODEV;
f975b339 BG	491	}
f7c2fe38	492
72a87a47	493	data->groups[group++] = &ina2xx_group;
70df9ebb	494	if (chip == ina226)
72a87a47 BG	495	data->groups[group++] = &ina226_group;
72a87a47 BG	496
468bf0e3	497	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
72a87a47	498	data, data->groups);
468bf0e3 GR	499	if (IS_ERR(hwmon_dev))
468bf0e3 GR	500	return PTR_ERR(hwmon_dev);
f7c2fe38	501
468bf0e3	502	dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n",
70df9ebb	503	client->name, data->rshunt);
6106db25	504
f7c2fe38	505	return 0;
f7c2fe38 FL	506	}
	507
	508	static const struct i2c_device_id ina2xx_id[] = {
	509	{ "ina219", ina219 },
dc92cd0c	510	{ "ina220", ina219 },
f7c2fe38	511	{ "ina226", ina226 },
dc92cd0c	512	{ "ina230", ina226 },
add513be	513	{ "ina231", ina226 },
f7c2fe38 FL	514	{ }
	515	};
	516	MODULE_DEVICE_TABLE(i2c, ina2xx_id);
	517
bd0ddd4d JMC	518	static const struct of_device_id ina2xx_of_match[] = {
	519	{
	520	.compatible = "ti,ina219",
	521	.data = (void *)ina219
	522	},
	523	{
	524	.compatible = "ti,ina220",
	525	.data = (void *)ina219
	526	},
	527	{
	528	.compatible = "ti,ina226",
	529	.data = (void *)ina226
	530	},
	531	{
	532	.compatible = "ti,ina230",
	533	.data = (void *)ina226
	534	},
	535	{
	536	.compatible = "ti,ina231",
	537	.data = (void *)ina226
	538	},
	539	{ },
	540	};
	541	MODULE_DEVICE_TABLE(of, ina2xx_of_match);
	542
f7c2fe38 FL	543	static struct i2c_driver ina2xx_driver = {
	544	.driver = {
	545	.name = "ina2xx",
bd0ddd4d	546	.of_match_table = of_match_ptr(ina2xx_of_match),
f7c2fe38 FL	547	},
f7c2fe38 FL	548	.probe = ina2xx_probe,
f7c2fe38 FL	549	.id_table = ina2xx_id,
	550	};
	551
d835ca0f	552	module_i2c_driver(ina2xx_driver);
f7c2fe38 FL	553
	554	MODULE_AUTHOR("Lothar Felten <[email protected]>");
	555	MODULE_DESCRIPTION("ina2xx driver");
	556	MODULE_LICENSE("GPL");