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![Lothar Felten](/assets/img/avatar_default.png)
fix the sysfs shunt resistor read access: return the shunt resistor value, not the calibration register contents. update email address Signed-off-by: Lothar Felten <lothar.felten@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
556 lines
14 KiB
C
556 lines
14 KiB
C
/*
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* Driver for Texas Instruments INA219, INA226 power monitor chips
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*
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* INA219:
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* Zero Drift Bi-Directional Current/Power Monitor with I2C Interface
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* Datasheet: http://www.ti.com/product/ina219
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*
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* INA220:
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* Bi-Directional Current/Power Monitor with I2C Interface
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* Datasheet: http://www.ti.com/product/ina220
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*
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* INA226:
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* Bi-Directional Current/Power Monitor with I2C Interface
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* Datasheet: http://www.ti.com/product/ina226
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*
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* INA230:
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* Bi-directional Current/Power Monitor with I2C Interface
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* Datasheet: http://www.ti.com/product/ina230
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*
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* Copyright (C) 2012 Lothar Felten <lothar.felten@gmail.com>
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* Thanks to Jan Volkering
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/jiffies.h>
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#include <linux/of_device.h>
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#include <linux/of.h>
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#include <linux/delay.h>
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#include <linux/util_macros.h>
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#include <linux/regmap.h>
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#include <linux/platform_data/ina2xx.h>
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/* common register definitions */
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#define INA2XX_CONFIG 0x00
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#define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */
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#define INA2XX_BUS_VOLTAGE 0x02 /* readonly */
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#define INA2XX_POWER 0x03 /* readonly */
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#define INA2XX_CURRENT 0x04 /* readonly */
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#define INA2XX_CALIBRATION 0x05
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/* INA226 register definitions */
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#define INA226_MASK_ENABLE 0x06
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#define INA226_ALERT_LIMIT 0x07
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#define INA226_DIE_ID 0xFF
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/* register count */
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#define INA219_REGISTERS 6
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#define INA226_REGISTERS 8
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#define INA2XX_MAX_REGISTERS 8
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/* settings - depend on use case */
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#define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
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#define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */
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/* worst case is 68.10 ms (~14.6Hz, ina219) */
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#define INA2XX_CONVERSION_RATE 15
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#define INA2XX_MAX_DELAY 69 /* worst case delay in ms */
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#define INA2XX_RSHUNT_DEFAULT 10000
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/* bit mask for reading the averaging setting in the configuration register */
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#define INA226_AVG_RD_MASK 0x0E00
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#define INA226_READ_AVG(reg) (((reg) & INA226_AVG_RD_MASK) >> 9)
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#define INA226_SHIFT_AVG(val) ((val) << 9)
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/* common attrs, ina226 attrs and NULL */
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#define INA2XX_MAX_ATTRIBUTE_GROUPS 3
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/*
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* Both bus voltage and shunt voltage conversion times for ina226 are set
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* to 0b0100 on POR, which translates to 2200 microseconds in total.
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*/
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#define INA226_TOTAL_CONV_TIME_DEFAULT 2200
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static struct regmap_config ina2xx_regmap_config = {
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.reg_bits = 8,
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.val_bits = 16,
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};
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enum ina2xx_ids { ina219, ina226 };
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struct ina2xx_config {
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u16 config_default;
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int calibration_value;
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int registers;
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int shunt_div;
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int bus_voltage_shift;
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int bus_voltage_lsb; /* uV */
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int power_lsb_factor;
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};
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struct ina2xx_data {
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const struct ina2xx_config *config;
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long rshunt;
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long current_lsb_uA;
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long power_lsb_uW;
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struct mutex config_lock;
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struct regmap *regmap;
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const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
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};
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static const struct ina2xx_config ina2xx_config[] = {
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[ina219] = {
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.config_default = INA219_CONFIG_DEFAULT,
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.calibration_value = 4096,
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.registers = INA219_REGISTERS,
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.shunt_div = 100,
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.bus_voltage_shift = 3,
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.bus_voltage_lsb = 4000,
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.power_lsb_factor = 20,
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},
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[ina226] = {
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.config_default = INA226_CONFIG_DEFAULT,
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.calibration_value = 2048,
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.registers = INA226_REGISTERS,
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.shunt_div = 400,
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.bus_voltage_shift = 0,
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.bus_voltage_lsb = 1250,
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.power_lsb_factor = 25,
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},
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};
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/*
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* Available averaging rates for ina226. The indices correspond with
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* the bit values expected by the chip (according to the ina226 datasheet,
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* table 3 AVG bit settings, found at
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* http://www.ti.com/lit/ds/symlink/ina226.pdf.
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*/
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static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
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static int ina226_reg_to_interval(u16 config)
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{
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int avg = ina226_avg_tab[INA226_READ_AVG(config)];
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/*
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* Multiply the total conversion time by the number of averages.
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* Return the result in milliseconds.
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*/
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return DIV_ROUND_CLOSEST(avg * INA226_TOTAL_CONV_TIME_DEFAULT, 1000);
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}
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/*
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* Return the new, shifted AVG field value of CONFIG register,
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* to use with regmap_update_bits
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*/
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static u16 ina226_interval_to_reg(int interval)
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{
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int avg, avg_bits;
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avg = DIV_ROUND_CLOSEST(interval * 1000,
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INA226_TOTAL_CONV_TIME_DEFAULT);
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avg_bits = find_closest(avg, ina226_avg_tab,
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ARRAY_SIZE(ina226_avg_tab));
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return INA226_SHIFT_AVG(avg_bits);
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}
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/*
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* Calibration register is set to the best value, which eliminates
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* truncation errors on calculating current register in hardware.
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* According to datasheet (eq. 3) the best values are 2048 for
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* ina226 and 4096 for ina219. They are hardcoded as calibration_value.
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*/
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static int ina2xx_calibrate(struct ina2xx_data *data)
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{
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return regmap_write(data->regmap, INA2XX_CALIBRATION,
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data->config->calibration_value);
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}
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/*
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* Initialize the configuration and calibration registers.
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*/
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static int ina2xx_init(struct ina2xx_data *data)
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{
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int ret = regmap_write(data->regmap, INA2XX_CONFIG,
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data->config->config_default);
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if (ret < 0)
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return ret;
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return ina2xx_calibrate(data);
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}
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static int ina2xx_read_reg(struct device *dev, int reg, unsigned int *regval)
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{
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struct ina2xx_data *data = dev_get_drvdata(dev);
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int ret, retry;
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dev_dbg(dev, "Starting register %d read\n", reg);
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for (retry = 5; retry; retry--) {
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ret = regmap_read(data->regmap, reg, regval);
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if (ret < 0)
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return ret;
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dev_dbg(dev, "read %d, val = 0x%04x\n", reg, *regval);
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/*
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* If the current value in the calibration register is 0, the
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* power and current registers will also remain at 0. In case
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* the chip has been reset let's check the calibration
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* register and reinitialize if needed.
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* We do that extra read of the calibration register if there
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* is some hint of a chip reset.
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*/
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if (*regval == 0) {
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unsigned int cal;
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ret = regmap_read(data->regmap, INA2XX_CALIBRATION,
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&cal);
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if (ret < 0)
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return ret;
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if (cal == 0) {
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dev_warn(dev, "chip not calibrated, reinitializing\n");
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ret = ina2xx_init(data);
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if (ret < 0)
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return ret;
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/*
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* Let's make sure the power and current
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* registers have been updated before trying
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* again.
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*/
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msleep(INA2XX_MAX_DELAY);
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continue;
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}
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}
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return 0;
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}
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/*
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* If we're here then although all write operations succeeded, the
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* chip still returns 0 in the calibration register. Nothing more we
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* can do here.
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*/
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dev_err(dev, "unable to reinitialize the chip\n");
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return -ENODEV;
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}
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static int ina2xx_get_value(struct ina2xx_data *data, u8 reg,
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unsigned int regval)
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{
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int val;
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switch (reg) {
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case INA2XX_SHUNT_VOLTAGE:
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/* signed register */
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val = DIV_ROUND_CLOSEST((s16)regval, data->config->shunt_div);
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break;
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case INA2XX_BUS_VOLTAGE:
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val = (regval >> data->config->bus_voltage_shift)
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* data->config->bus_voltage_lsb;
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val = DIV_ROUND_CLOSEST(val, 1000);
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break;
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case INA2XX_POWER:
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val = regval * data->power_lsb_uW;
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break;
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case INA2XX_CURRENT:
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/* signed register, result in mA */
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val = regval * data->current_lsb_uA;
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val = DIV_ROUND_CLOSEST(val, 1000);
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break;
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case INA2XX_CALIBRATION:
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val = regval;
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break;
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default:
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/* programmer goofed */
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WARN_ON_ONCE(1);
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val = 0;
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break;
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}
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return val;
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}
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static ssize_t ina2xx_show_value(struct device *dev,
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struct device_attribute *da, char *buf)
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{
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struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
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struct ina2xx_data *data = dev_get_drvdata(dev);
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unsigned int regval;
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int err = ina2xx_read_reg(dev, attr->index, ®val);
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if (err < 0)
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return err;
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return snprintf(buf, PAGE_SIZE, "%d\n",
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ina2xx_get_value(data, attr->index, regval));
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}
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/*
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* In order to keep calibration register value fixed, the product
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* of current_lsb and shunt_resistor should also be fixed and equal
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* to shunt_voltage_lsb = 1 / shunt_div multiplied by 10^9 in order
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* to keep the scale.
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*/
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static int ina2xx_set_shunt(struct ina2xx_data *data, long val)
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{
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unsigned int dividend = DIV_ROUND_CLOSEST(1000000000,
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data->config->shunt_div);
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if (val <= 0 || val > dividend)
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return -EINVAL;
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mutex_lock(&data->config_lock);
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data->rshunt = val;
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data->current_lsb_uA = DIV_ROUND_CLOSEST(dividend, val);
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data->power_lsb_uW = data->config->power_lsb_factor *
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data->current_lsb_uA;
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mutex_unlock(&data->config_lock);
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return 0;
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}
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static ssize_t ina2xx_show_shunt(struct device *dev,
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struct device_attribute *da,
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char *buf)
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{
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struct ina2xx_data *data = dev_get_drvdata(dev);
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return snprintf(buf, PAGE_SIZE, "%li\n", data->rshunt);
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}
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static ssize_t ina2xx_store_shunt(struct device *dev,
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struct device_attribute *da,
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const char *buf, size_t count)
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{
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unsigned long val;
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int status;
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struct ina2xx_data *data = dev_get_drvdata(dev);
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status = kstrtoul(buf, 10, &val);
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if (status < 0)
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return status;
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status = ina2xx_set_shunt(data, val);
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if (status < 0)
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return status;
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return count;
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}
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static ssize_t ina226_set_interval(struct device *dev,
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struct device_attribute *da,
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const char *buf, size_t count)
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{
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struct ina2xx_data *data = dev_get_drvdata(dev);
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unsigned long val;
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int status;
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status = kstrtoul(buf, 10, &val);
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if (status < 0)
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return status;
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if (val > INT_MAX || val == 0)
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return -EINVAL;
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status = regmap_update_bits(data->regmap, INA2XX_CONFIG,
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INA226_AVG_RD_MASK,
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ina226_interval_to_reg(val));
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if (status < 0)
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return status;
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return count;
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}
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static ssize_t ina226_show_interval(struct device *dev,
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struct device_attribute *da, char *buf)
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{
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struct ina2xx_data *data = dev_get_drvdata(dev);
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int status;
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unsigned int regval;
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status = regmap_read(data->regmap, INA2XX_CONFIG, ®val);
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if (status)
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return status;
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return snprintf(buf, PAGE_SIZE, "%d\n", ina226_reg_to_interval(regval));
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}
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/* shunt voltage */
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static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
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INA2XX_SHUNT_VOLTAGE);
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/* bus voltage */
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static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina2xx_show_value, NULL,
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INA2XX_BUS_VOLTAGE);
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/* calculated current */
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static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina2xx_show_value, NULL,
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INA2XX_CURRENT);
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/* calculated power */
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static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina2xx_show_value, NULL,
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INA2XX_POWER);
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/* shunt resistance */
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static SENSOR_DEVICE_ATTR(shunt_resistor, S_IRUGO | S_IWUSR,
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ina2xx_show_shunt, ina2xx_store_shunt,
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INA2XX_CALIBRATION);
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/* update interval (ina226 only) */
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static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR,
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ina226_show_interval, ina226_set_interval, 0);
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/* pointers to created device attributes */
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static struct attribute *ina2xx_attrs[] = {
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&sensor_dev_attr_in0_input.dev_attr.attr,
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&sensor_dev_attr_in1_input.dev_attr.attr,
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&sensor_dev_attr_curr1_input.dev_attr.attr,
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&sensor_dev_attr_power1_input.dev_attr.attr,
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&sensor_dev_attr_shunt_resistor.dev_attr.attr,
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NULL,
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};
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static const struct attribute_group ina2xx_group = {
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.attrs = ina2xx_attrs,
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};
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static struct attribute *ina226_attrs[] = {
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&sensor_dev_attr_update_interval.dev_attr.attr,
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NULL,
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};
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static const struct attribute_group ina226_group = {
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.attrs = ina226_attrs,
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};
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static int ina2xx_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct device *dev = &client->dev;
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struct ina2xx_data *data;
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struct device *hwmon_dev;
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u32 val;
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int ret, group = 0;
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enum ina2xx_ids chip;
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if (client->dev.of_node)
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chip = (enum ina2xx_ids)of_device_get_match_data(&client->dev);
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else
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chip = id->driver_data;
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data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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/* set the device type */
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data->config = &ina2xx_config[chip];
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mutex_init(&data->config_lock);
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if (of_property_read_u32(dev->of_node, "shunt-resistor", &val) < 0) {
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struct ina2xx_platform_data *pdata = dev_get_platdata(dev);
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if (pdata)
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val = pdata->shunt_uohms;
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else
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val = INA2XX_RSHUNT_DEFAULT;
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}
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ina2xx_set_shunt(data, val);
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ina2xx_regmap_config.max_register = data->config->registers;
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data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
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if (IS_ERR(data->regmap)) {
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dev_err(dev, "failed to allocate register map\n");
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return PTR_ERR(data->regmap);
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}
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ret = ina2xx_init(data);
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if (ret < 0) {
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dev_err(dev, "error configuring the device: %d\n", ret);
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return -ENODEV;
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}
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data->groups[group++] = &ina2xx_group;
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if (id->driver_data == ina226)
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data->groups[group++] = &ina226_group;
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hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
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data, data->groups);
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if (IS_ERR(hwmon_dev))
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return PTR_ERR(hwmon_dev);
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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");
|