linux-imx

/*

 * Copyright (C) 2017 IBM Corp.

 *

 * 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; either version 2 of the License, or

 * (at your option) any later version.

 *

 * Driver for the Nuvoton W83773G SMBus temperature sensor IC.

 * Supported models: W83773G

 */

​

#include <linux/module.h>

#include <linux/init.h>

#include <linux/i2c.h>

#include <linux/hwmon.h>

#include <linux/hwmon-sysfs.h>

#include <linux/err.h>

#include <linux/of_device.h>

#include <linux/regmap.h>

​

/* W83773 has 3 channels */

#define W83773_CHANNELS             3

​

/* The W83773 registers */

#define W83773_CONVERSION_RATE_REG_READ     0x04

#define W83773_CONVERSION_RATE_REG_WRITE    0x0A

#define W83773_MANUFACTURER_ID_REG      0xFE

#define W83773_LOCAL_TEMP           0x00

​

static const u8 W83773_STATUS[2] = { 0x02, 0x17 };

​

static const u8 W83773_TEMP_LSB[2] = { 0x10, 0x25 };

static const u8 W83773_TEMP_MSB[2] = { 0x01, 0x24 };

​

static const u8 W83773_OFFSET_LSB[2] = { 0x12, 0x16 };

static const u8 W83773_OFFSET_MSB[2] = { 0x11, 0x15 };

​

/* this is the number of sensors in the device */

static const struct i2c_device_id w83773_id[] = {

    { "w83773g" },

    { }

};

​

MODULE_DEVICE_TABLE(i2c, w83773_id);

​

static const struct of_device_id w83773_of_match[] = {

    {

        .compatible = "nuvoton,w83773g"

    },

    { },

};

MODULE_DEVICE_TABLE(of, w83773_of_match);

​

static inline long temp_of_local(s8 reg)

{

    return reg * 1000;

}

​

static inline long temp_of_remote(s8 hb, u8 lb)

{

    return (hb << 3 | lb >> 5) * 125;

}

​

static int get_local_temp(struct regmap *regmap, long *val)

{

    unsigned int regval;

    int ret;

​

    ret = regmap_read(regmap, W83773_LOCAL_TEMP, &regval);

    if (ret < 0)

        return ret;

​

    *val = temp_of_local(regval);

    return 0;

}

​

static int get_remote_temp(struct regmap *regmap, int index, long *val)

{

    unsigned int regval_high;

    unsigned int regval_low;

    int ret;

​

    ret = regmap_read(regmap, W83773_TEMP_MSB[index], &regval_high);

    if (ret < 0)

        return ret;

​

    ret = regmap_read(regmap, W83773_TEMP_LSB[index], &regval_low);

    if (ret < 0)

        return ret;

​

    *val = temp_of_remote(regval_high, regval_low);