/* * 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_value_show(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_shunt_show(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_shunt_store(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_interval_store(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_interval_show(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_RO(in0_input, ina2xx_value, INA2XX_SHUNT_VOLTAGE); /* bus voltage */ static SENSOR_DEVICE_ATTR_RO(in1_input, ina2xx_value, INA2XX_BUS_VOLTAGE); /* calculated current */ static SENSOR_DEVICE_ATTR_RO(curr1_input, ina2xx_value, INA2XX_CURRENT); /* calculated power */ static SENSOR_DEVICE_ATTR_RO(power1_input, ina2xx_value, INA2XX_POWER); /* shunt resistance */ static SENSOR_DEVICE_ATTR_RW(shunt_resistor, ina2xx_shunt, INA2XX_CALIBRATION); /* update interval (ina226 only) */ static SENSOR_DEVICE_ATTR_RW(update_interval, ina226_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");