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d38df34e3f
Use find_closest() to locate the closest average in ina226_avg_tab. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
548 lines
14 KiB
C
548 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 <l-felten@ti.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.h>
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#include <linux/delay.h>
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#include <linux/util_macros.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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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_factor;
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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; /* uW */
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};
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struct ina2xx_data {
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struct i2c_client *client;
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const struct ina2xx_config *config;
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long rshunt;
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u16 curr_config;
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struct mutex update_lock;
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bool valid;
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unsigned long last_updated;
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int update_interval; /* in jiffies */
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int kind;
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const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
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u16 regs[INA2XX_MAX_REGISTERS];
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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_factor = 40960000,
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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 = 20000,
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},
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[ina226] = {
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.config_default = INA226_CONFIG_DEFAULT,
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.calibration_factor = 5120000,
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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 = 25000,
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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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static u16 ina226_interval_to_reg(int interval, u16 config)
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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 (config & ~INA226_AVG_RD_MASK) | INA226_SHIFT_AVG(avg_bits);
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}
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static void ina226_set_update_interval(struct ina2xx_data *data)
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{
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int ms;
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ms = ina226_reg_to_interval(data->curr_config);
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data->update_interval = msecs_to_jiffies(ms);
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}
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static int ina2xx_calibrate(struct ina2xx_data *data)
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{
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u16 val = DIV_ROUND_CLOSEST(data->config->calibration_factor,
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data->rshunt);
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return i2c_smbus_write_word_swapped(data->client,
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INA2XX_CALIBRATION, val);
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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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struct i2c_client *client = data->client;
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int ret;
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/* device configuration */
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ret = i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
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data->curr_config);
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if (ret < 0)
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return ret;
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/*
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* Set current LSB to 1mA, shunt is in uOhms
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* (equation 13 in datasheet).
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*/
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return ina2xx_calibrate(data);
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}
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static int ina2xx_do_update(struct device *dev)
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{
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struct ina2xx_data *data = dev_get_drvdata(dev);
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struct i2c_client *client = data->client;
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int i, rv, retry;
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dev_dbg(&client->dev, "Starting ina2xx update\n");
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for (retry = 5; retry; retry--) {
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/* Read all registers */
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for (i = 0; i < data->config->registers; i++) {
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rv = i2c_smbus_read_word_swapped(client, i);
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if (rv < 0)
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return rv;
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data->regs[i] = rv;
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}
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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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*/
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if (data->regs[INA2XX_CALIBRATION] == 0) {
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dev_warn(dev, "chip not calibrated, reinitializing\n");
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rv = ina2xx_init(data);
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if (rv < 0)
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return rv;
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/*
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* Let's make sure the power and current registers
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* have been updated before trying 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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data->last_updated = jiffies;
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data->valid = 1;
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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 struct ina2xx_data *ina2xx_update_device(struct device *dev)
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{
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struct ina2xx_data *data = dev_get_drvdata(dev);
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struct ina2xx_data *ret = data;
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unsigned long after;
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int rv;
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mutex_lock(&data->update_lock);
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after = data->last_updated + data->update_interval;
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if (time_after(jiffies, after) || !data->valid) {
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rv = ina2xx_do_update(dev);
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if (rv < 0)
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ret = ERR_PTR(rv);
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}
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mutex_unlock(&data->update_lock);
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return ret;
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}
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static int ina2xx_get_value(struct ina2xx_data *data, u8 reg)
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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)data->regs[reg],
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data->config->shunt_div);
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break;
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case INA2XX_BUS_VOLTAGE:
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val = (data->regs[reg] >> 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 = data->regs[reg] * data->config->power_lsb;
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break;
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case INA2XX_CURRENT:
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/* signed register, LSB=1mA (selected), in mA */
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val = (s16)data->regs[reg];
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break;
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case INA2XX_CALIBRATION:
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val = DIV_ROUND_CLOSEST(data->config->calibration_factor,
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data->regs[reg]);
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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 = ina2xx_update_device(dev);
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if (IS_ERR(data))
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return PTR_ERR(data);
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return snprintf(buf, PAGE_SIZE, "%d\n",
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ina2xx_get_value(data, attr->index));
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}
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static ssize_t ina2xx_set_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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struct ina2xx_data *data = ina2xx_update_device(dev);
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unsigned long val;
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int status;
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if (IS_ERR(data))
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return PTR_ERR(data);
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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 == 0 ||
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/* Values greater than the calibration factor make no sense. */
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val > data->config->calibration_factor)
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return -EINVAL;
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mutex_lock(&data->update_lock);
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data->rshunt = val;
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status = ina2xx_calibrate(data);
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mutex_unlock(&data->update_lock);
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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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mutex_lock(&data->update_lock);
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data->curr_config = ina226_interval_to_reg(val,
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data->regs[INA2XX_CONFIG]);
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status = i2c_smbus_write_word_swapped(data->client,
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INA2XX_CONFIG,
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data->curr_config);
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ina226_set_update_interval(data);
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/* Make sure the next access re-reads all registers. */
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data->valid = 0;
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mutex_unlock(&data->update_lock);
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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 = ina2xx_update_device(dev);
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if (IS_ERR(data))
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return PTR_ERR(data);
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/*
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* We don't use data->update_interval here as we want to display
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* the actual interval used by the chip and jiffies_to_msecs()
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* doesn't seem to be accurate enough.
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*/
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return snprintf(buf, PAGE_SIZE, "%d\n",
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ina226_reg_to_interval(data->regs[INA2XX_CONFIG]));
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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_value, ina2xx_set_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 i2c_adapter *adapter = client->adapter;
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struct ina2xx_platform_data *pdata;
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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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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
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return -ENODEV;
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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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if (dev_get_platdata(dev)) {
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pdata = dev_get_platdata(dev);
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data->rshunt = pdata->shunt_uohms;
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} else if (!of_property_read_u32(dev->of_node,
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"shunt-resistor", &val)) {
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data->rshunt = val;
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} else {
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data->rshunt = INA2XX_RSHUNT_DEFAULT;
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}
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/* set the device type */
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data->kind = id->driver_data;
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data->config = &ina2xx_config[data->kind];
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data->curr_config = data->config->config_default;
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data->client = client;
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/*
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* Ina226 has a variable update_interval. For ina219 we
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* use a constant value.
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*/
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if (data->kind == ina226)
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ina226_set_update_interval(data);
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else
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data->update_interval = HZ / INA2XX_CONVERSION_RATE;
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if (data->rshunt <= 0 ||
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data->rshunt > data->config->calibration_factor)
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return -ENODEV;
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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);
|
|
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 <l-felten@ti.com>");
|
|
MODULE_DESCRIPTION("ina2xx driver");
|
|
MODULE_LICENSE("GPL");
|