diff options
Diffstat (limited to 'drivers/hwmon/ina2xx.c')
| -rw-r--r-- | drivers/hwmon/ina2xx.c | 556 |
1 files changed, 556 insertions, 0 deletions
diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c new file mode 100644 index 000000000..07ee19573 --- /dev/null +++ b/drivers/hwmon/ina2xx.c @@ -0,0 +1,556 @@ +/* + * 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 <lothar.felten@gmail.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 = (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, ®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_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, ®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_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 <l-felten@ti.com>"); +MODULE_DESCRIPTION("ina2xx driver"); +MODULE_LICENSE("GPL"); |