linux/drivers/hwmon/tmp103.c
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   1/*
   2 * Texas Instruments TMP103 SMBus temperature sensor driver
   3 * Copyright (C) 2014 Heiko Schocher <hs@denx.de>
   4 *
   5 * Based on:
   6 * Texas Instruments TMP102 SMBus temperature sensor driver
   7 *
   8 * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License as published by
  12 * the Free Software Foundation; either version 2 of the License, or
  13 * (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 * GNU General Public License for more details.
  19 *
  20 */
  21
  22#include <linux/module.h>
  23#include <linux/init.h>
  24#include <linux/slab.h>
  25#include <linux/i2c.h>
  26#include <linux/hwmon.h>
  27#include <linux/hwmon-sysfs.h>
  28#include <linux/err.h>
  29#include <linux/mutex.h>
  30#include <linux/device.h>
  31#include <linux/jiffies.h>
  32#include <linux/regmap.h>
  33
  34#define TMP103_TEMP_REG         0x00
  35#define TMP103_CONF_REG         0x01
  36#define TMP103_TLOW_REG         0x02
  37#define TMP103_THIGH_REG        0x03
  38
  39#define TMP103_CONF_M0          0x01
  40#define TMP103_CONF_M1          0x02
  41#define TMP103_CONF_LC          0x04
  42#define TMP103_CONF_FL          0x08
  43#define TMP103_CONF_FH          0x10
  44#define TMP103_CONF_CR0         0x20
  45#define TMP103_CONF_CR1         0x40
  46#define TMP103_CONF_ID          0x80
  47#define TMP103_CONF_SD          (TMP103_CONF_M1)
  48#define TMP103_CONF_SD_MASK     (TMP103_CONF_M0 | TMP103_CONF_M1)
  49
  50#define TMP103_CONFIG           (TMP103_CONF_CR1 | TMP103_CONF_M1)
  51#define TMP103_CONFIG_MASK      (TMP103_CONF_CR0 | TMP103_CONF_CR1 | \
  52                                 TMP103_CONF_M0 | TMP103_CONF_M1)
  53
  54static inline int tmp103_reg_to_mc(s8 val)
  55{
  56        return val * 1000;
  57}
  58
  59static inline u8 tmp103_mc_to_reg(int val)
  60{
  61        return DIV_ROUND_CLOSEST(val, 1000);
  62}
  63
  64static ssize_t tmp103_show_temp(struct device *dev,
  65                                struct device_attribute *attr,
  66                                char *buf)
  67{
  68        struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  69        struct regmap *regmap = dev_get_drvdata(dev);
  70        unsigned int regval;
  71        int ret;
  72
  73        ret = regmap_read(regmap, sda->index, &regval);
  74        if (ret < 0)
  75                return ret;
  76
  77        return sprintf(buf, "%d\n", tmp103_reg_to_mc(regval));
  78}
  79
  80static ssize_t tmp103_set_temp(struct device *dev,
  81                               struct device_attribute *attr,
  82                               const char *buf, size_t count)
  83{
  84        struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  85        struct regmap *regmap = dev_get_drvdata(dev);
  86        long val;
  87        int ret;
  88
  89        if (kstrtol(buf, 10, &val) < 0)
  90                return -EINVAL;
  91
  92        val = clamp_val(val, -55000, 127000);
  93        ret = regmap_write(regmap, sda->index, tmp103_mc_to_reg(val));
  94        return ret ? ret : count;
  95}
  96
  97static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp103_show_temp, NULL ,
  98                          TMP103_TEMP_REG);
  99
 100static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, tmp103_show_temp,
 101                          tmp103_set_temp, TMP103_TLOW_REG);
 102
 103static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp103_show_temp,
 104                          tmp103_set_temp, TMP103_THIGH_REG);
 105
 106static struct attribute *tmp103_attrs[] = {
 107        &sensor_dev_attr_temp1_input.dev_attr.attr,
 108        &sensor_dev_attr_temp1_min.dev_attr.attr,
 109        &sensor_dev_attr_temp1_max.dev_attr.attr,
 110        NULL
 111};
 112ATTRIBUTE_GROUPS(tmp103);
 113
 114static bool tmp103_regmap_is_volatile(struct device *dev, unsigned int reg)
 115{
 116        return reg == TMP103_TEMP_REG;
 117}
 118
 119static const struct regmap_config tmp103_regmap_config = {
 120        .reg_bits = 8,
 121        .val_bits = 8,
 122        .max_register = TMP103_THIGH_REG,
 123        .volatile_reg = tmp103_regmap_is_volatile,
 124};
 125
 126static int tmp103_probe(struct i2c_client *client,
 127                        const struct i2c_device_id *id)
 128{
 129        struct device *dev = &client->dev;
 130        struct device *hwmon_dev;
 131        struct regmap *regmap;
 132        int ret;
 133
 134        regmap = devm_regmap_init_i2c(client, &tmp103_regmap_config);
 135        if (IS_ERR(regmap)) {
 136                dev_err(dev, "failed to allocate register map\n");
 137                return PTR_ERR(regmap);
 138        }
 139
 140        ret = regmap_update_bits(regmap, TMP103_CONF_REG, TMP103_CONFIG_MASK,
 141                                 TMP103_CONFIG);
 142        if (ret < 0) {
 143                dev_err(&client->dev, "error writing config register\n");
 144                return ret;
 145        }
 146
 147        i2c_set_clientdata(client, regmap);
 148        hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 149                                                      regmap, tmp103_groups);
 150        return PTR_ERR_OR_ZERO(hwmon_dev);
 151}
 152
 153static int __maybe_unused tmp103_suspend(struct device *dev)
 154{
 155        struct regmap *regmap = dev_get_drvdata(dev);
 156
 157        return regmap_update_bits(regmap, TMP103_CONF_REG,
 158                                  TMP103_CONF_SD_MASK, 0);
 159}
 160
 161static int __maybe_unused tmp103_resume(struct device *dev)
 162{
 163        struct regmap *regmap = dev_get_drvdata(dev);
 164
 165        return regmap_update_bits(regmap, TMP103_CONF_REG,
 166                                  TMP103_CONF_SD_MASK, TMP103_CONF_SD);
 167}
 168
 169static SIMPLE_DEV_PM_OPS(tmp103_dev_pm_ops, tmp103_suspend, tmp103_resume);
 170
 171static const struct i2c_device_id tmp103_id[] = {
 172        { "tmp103", 0 },
 173        { }
 174};
 175MODULE_DEVICE_TABLE(i2c, tmp103_id);
 176
 177static const struct of_device_id tmp103_of_match[] = {
 178        { .compatible = "ti,tmp103" },
 179        { },
 180};
 181MODULE_DEVICE_TABLE(of, tmp103_of_match);
 182
 183static struct i2c_driver tmp103_driver = {
 184        .driver = {
 185                .name   = "tmp103",
 186                .of_match_table = of_match_ptr(tmp103_of_match),
 187                .pm     = &tmp103_dev_pm_ops,
 188        },
 189        .probe          = tmp103_probe,
 190        .id_table       = tmp103_id,
 191};
 192
 193module_i2c_driver(tmp103_driver);
 194
 195MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
 196MODULE_DESCRIPTION("Texas Instruments TMP103 temperature sensor driver");
 197MODULE_LICENSE("GPL");
 198