From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/hwmon/ina2xx.c | 547 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 547 insertions(+) create mode 100644 drivers/hwmon/ina2xx.c (limited to 'drivers/hwmon/ina2xx.c') diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c new file mode 100644 index 000000000..4d2815079 --- /dev/null +++ b/drivers/hwmon/ina2xx.c @@ -0,0 +1,547 @@ +/* + * 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 + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/* 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 + +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; + + long rshunt; + u16 curr_config; + + struct mutex update_lock; + bool valid; + unsigned long last_updated; + int update_interval; /* in jiffies */ + + int kind; + const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS]; + 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, + }, +}; + +/* + * 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); +} + +static u16 ina226_interval_to_reg(int interval, u16 config) +{ + 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 (config & ~INA226_AVG_RD_MASK) | INA226_SHIFT_AVG(avg_bits); +} + +static void ina226_set_update_interval(struct ina2xx_data *data) +{ + int ms; + + ms = ina226_reg_to_interval(data->curr_config); + data->update_interval = msecs_to_jiffies(ms); +} + +static int ina2xx_calibrate(struct ina2xx_data *data) +{ + u16 val = DIV_ROUND_CLOSEST(data->config->calibration_factor, + data->rshunt); + + return i2c_smbus_write_word_swapped(data->client, + INA2XX_CALIBRATION, val); +} + +/* + * Initialize the configuration and calibration registers. + */ +static int ina2xx_init(struct ina2xx_data *data) +{ + struct i2c_client *client = data->client; + int ret; + + /* device configuration */ + ret = i2c_smbus_write_word_swapped(client, INA2XX_CONFIG, + data->curr_config); + if (ret < 0) + return ret; + + /* + * Set current LSB to 1mA, shunt is in uOhms + * (equation 13 in datasheet). + */ + return ina2xx_calibrate(data); +} + +static int ina2xx_do_update(struct device *dev) +{ + struct ina2xx_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + int i, rv, retry; + + dev_dbg(&client->dev, "Starting ina2xx update\n"); + + for (retry = 5; retry; retry--) { + /* Read all registers */ + for (i = 0; i < data->config->registers; i++) { + rv = i2c_smbus_read_word_swapped(client, i); + if (rv < 0) + return rv; + data->regs[i] = rv; + } + + /* + * 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. + */ + if (data->regs[INA2XX_CALIBRATION] == 0) { + dev_warn(dev, "chip not calibrated, reinitializing\n"); + + rv = ina2xx_init(data); + if (rv < 0) + return rv; + + /* + * Let's make sure the power and current registers + * have been updated before trying again. + */ + msleep(INA2XX_MAX_DELAY); + continue; + } + + data->last_updated = jiffies; + data->valid = 1; + + 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 struct ina2xx_data *ina2xx_update_device(struct device *dev) +{ + struct ina2xx_data *data = dev_get_drvdata(dev); + struct ina2xx_data *ret = data; + unsigned long after; + int rv; + + mutex_lock(&data->update_lock); + + after = data->last_updated + data->update_interval; + if (time_after(jiffies, after) || !data->valid) { + rv = ina2xx_do_update(dev); + if (rv < 0) + ret = ERR_PTR(rv); + } + + 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; + case INA2XX_CALIBRATION: + val = DIV_ROUND_CLOSEST(data->config->calibration_factor, + 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)); +} + +static ssize_t ina2xx_set_shunt(struct device *dev, + struct device_attribute *da, + const char *buf, size_t count) +{ + struct ina2xx_data *data = ina2xx_update_device(dev); + unsigned long val; + int status; + + if (IS_ERR(data)) + return PTR_ERR(data); + + status = kstrtoul(buf, 10, &val); + if (status < 0) + return status; + + if (val == 0 || + /* Values greater than the calibration factor make no sense. */ + val > data->config->calibration_factor) + return -EINVAL; + + mutex_lock(&data->update_lock); + data->rshunt = val; + status = ina2xx_calibrate(data); + mutex_unlock(&data->update_lock); + 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; + + mutex_lock(&data->update_lock); + data->curr_config = ina226_interval_to_reg(val, + data->regs[INA2XX_CONFIG]); + status = i2c_smbus_write_word_swapped(data->client, + INA2XX_CONFIG, + data->curr_config); + + ina226_set_update_interval(data); + /* Make sure the next access re-reads all registers. */ + data->valid = 0; + mutex_unlock(&data->update_lock); + 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 = ina2xx_update_device(dev); + + if (IS_ERR(data)) + return PTR_ERR(data); + + /* + * We don't use data->update_interval here as we want to display + * the actual interval used by the chip and jiffies_to_msecs() + * doesn't seem to be accurate enough. + */ + return snprintf(buf, PAGE_SIZE, "%d\n", + ina226_reg_to_interval(data->regs[INA2XX_CONFIG])); +} + +/* 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_set_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 i2c_adapter *adapter = client->adapter; + struct ina2xx_platform_data *pdata; + struct device *dev = &client->dev; + struct ina2xx_data *data; + struct device *hwmon_dev; + u32 val; + int ret, group = 0; + + 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); + data->rshunt = pdata->shunt_uohms; + } else if (!of_property_read_u32(dev->of_node, + "shunt-resistor", &val)) { + data->rshunt = val; + } else { + data->rshunt = INA2XX_RSHUNT_DEFAULT; + } + + /* set the device type */ + data->kind = id->driver_data; + data->config = &ina2xx_config[data->kind]; + data->curr_config = data->config->config_default; + data->client = client; + + /* + * Ina226 has a variable update_interval. For ina219 we + * use a constant value. + */ + if (data->kind == ina226) + ina226_set_update_interval(data); + else + data->update_interval = HZ / INA2XX_CONVERSION_RATE; + + if (data->rshunt <= 0 || + data->rshunt > data->config->calibration_factor) + return -ENODEV; + + ret = ina2xx_init(data); + if (ret < 0) { + dev_err(dev, "error configuring the device: %d\n", ret); + return -ENODEV; + } + + mutex_init(&data->update_lock); + + data->groups[group++] = &ina2xx_group; + if (data->kind == 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 struct i2c_driver ina2xx_driver = { + .driver = { + .name = "ina2xx", + }, + .probe = ina2xx_probe, + .id_table = ina2xx_id, +}; + +module_i2c_driver(ina2xx_driver); + +MODULE_AUTHOR("Lothar Felten "); +MODULE_DESCRIPTION("ina2xx driver"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3-54-g00ecf