/*
* 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_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 = 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, ®val);
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_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, ®val);
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_value, 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 (id->driver_data == 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",
id->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 <l-felten@ti.com>");
MODULE_DESCRIPTION("ina2xx driver");
MODULE_LICENSE("GPL");
