diff options
Diffstat (limited to 'drivers/hwmon/ina2xx.c')
| -rw-r--r-- | drivers/hwmon/ina2xx.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c new file mode 100644 index 00000000000..bfd3f3eeabc --- /dev/null +++ b/drivers/hwmon/ina2xx.c @@ -0,0 +1,292 @@ +/* + * 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.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 + +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; + + struct mutex update_lock; + bool valid; + unsigned long last_updated; + + int kind; + 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, + }, +}; + +static struct ina2xx_data *ina2xx_update_device(struct device *dev) +{ + struct ina2xx_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + struct ina2xx_data *ret = data; + + mutex_lock(&data->update_lock); + + if (time_after(jiffies, data->last_updated + + HZ / INA2XX_CONVERSION_RATE) || !data->valid) { + + int i; + + dev_dbg(&client->dev, "Starting ina2xx update\n"); + + /* Read all registers */ + for (i = 0; i < data->config->registers; i++) { + int rv = i2c_smbus_read_word_swapped(client, i); + if (rv < 0) { + ret = ERR_PTR(rv); + goto abort; + } + data->regs[i] = rv; + } + data->last_updated = jiffies; + data->valid = 1; + } +abort: + 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; + 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)); +} + +/* 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); + +/* 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, + NULL, +}; +ATTRIBUTE_GROUPS(ina2xx); + +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; + long shunt = 10000; /* default shunt value 10mOhms */ + u32 val; + + 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); + shunt = pdata->shunt_uohms; + } else if (!of_property_read_u32(dev->of_node, + "shunt-resistor", &val)) { + shunt = val; + } + + if (shunt <= 0) + return -ENODEV; + + /* set the device type */ + data->kind = id->driver_data; + data->config = &ina2xx_config[data->kind]; + + /* device configuration */ + i2c_smbus_write_word_swapped(client, INA2XX_CONFIG, + data->config->config_default); + /* set current LSB to 1mA, shunt is in uOhms */ + /* (equation 13 in datasheet) */ + i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION, + data->config->calibration_factor / shunt); + + data->client = client; + mutex_init(&data->update_lock); + + hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, + data, ina2xx_groups); + if (IS_ERR(hwmon_dev)) + return PTR_ERR(hwmon_dev); + + dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n", + id->name, shunt); + + return 0; +} + +static const struct i2c_device_id ina2xx_id[] = { + { "ina219", ina219 }, + { "ina220", ina219 }, + { "ina226", ina226 }, + { "ina230", 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 <l-felten@ti.com>"); +MODULE_DESCRIPTION("ina2xx driver"); +MODULE_LICENSE("GPL"); |