drivers/hwmon/tmp103.c

   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
  54 static inline int tmp103_reg_to_mc(s8 val)
  55 {
  56         return val * 1000;
  57 }
  58
  59 static inline u8 tmp103_mc_to_reg(int val)
  60 {
  61         return DIV_ROUND_CLOSEST(val, 1000);
  62 }
  63
  64 static ssize_t tmp103_temp_show(struct device *dev,
  65                                 struct device_attribute *attr, char *buf)
  66 {
  67         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  68         struct regmap *regmap = dev_get_drvdata(dev);
  69         unsigned int regval;
  70         int ret;
  71
  72         ret = regmap_read(regmap, sda->index, &regval);
  73         if (ret < 0)
  74                 return ret;
  75
  76         return sprintf(buf, "%d\n", tmp103_reg_to_mc(regval));
  77 }
  78
  79 static ssize_t tmp103_temp_store(struct device *dev,
  80                                  struct device_attribute *attr,
  81                                  const char *buf, size_t count)
  82 {
  83         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
  84         struct regmap *regmap = dev_get_drvdata(dev);
  85         long val;
  86         int ret;
  87
  88         if (kstrtol(buf, 10, &val) < 0)
  89                 return -EINVAL;
  90
  91         val = clamp_val(val, -55000, 127000);
  92         ret = regmap_write(regmap, sda->index, tmp103_mc_to_reg(val));
  93         return ret ? ret : count;
  94 }
  95
  96 static SENSOR_DEVICE_ATTR_RO(temp1_input, tmp103_temp, TMP103_TEMP_REG);
  97
  98 static SENSOR_DEVICE_ATTR_RW(temp1_min, tmp103_temp, TMP103_TLOW_REG);
  99
 100 static SENSOR_DEVICE_ATTR_RW(temp1_max, tmp103_temp, TMP103_THIGH_REG);
 101
 102 static struct attribute *tmp103_attrs[] = {
 103         &sensor_dev_attr_temp1_input.dev_attr.attr,
 104         &sensor_dev_attr_temp1_min.dev_attr.attr,
 105         &sensor_dev_attr_temp1_max.dev_attr.attr,
 106         NULL
 107 };
 108 ATTRIBUTE_GROUPS(tmp103);
 109
 110 static bool tmp103_regmap_is_volatile(struct device *dev, unsigned int reg)
 111 {
 112         return reg == TMP103_TEMP_REG;
 113 }
 114
 115 static const struct regmap_config tmp103_regmap_config = {
 116         .reg_bits = 8,
 117         .val_bits = 8,
 118         .max_register = TMP103_THIGH_REG,
 119         .volatile_reg = tmp103_regmap_is_volatile,
 120 };
 121
 122 static int tmp103_probe(struct i2c_client *client,
 123                         const struct i2c_device_id *id)
 124 {
 125         struct device *dev = &client->dev;
 126         struct device *hwmon_dev;
 127         struct regmap *regmap;
 128         int ret;
 129
 130         regmap = devm_regmap_init_i2c(client, &tmp103_regmap_config);
 131         if (IS_ERR(regmap)) {
 132                 dev_err(dev, "failed to allocate register map\n");
 133                 return PTR_ERR(regmap);
 134         }
 135
 136         ret = regmap_update_bits(regmap, TMP103_CONF_REG, TMP103_CONFIG_MASK,
 137                                  TMP103_CONFIG);
 138         if (ret < 0) {
 139                 dev_err(&client->dev, "error writing config register\n");
 140                 return ret;
 141         }
 142
 143         i2c_set_clientdata(client, regmap);
 144         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 145                                                       regmap, tmp103_groups);
 146         return PTR_ERR_OR_ZERO(hwmon_dev);
 147 }
 148
 149 static int __maybe_unused tmp103_suspend(struct device *dev)
 150 {
 151         struct regmap *regmap = dev_get_drvdata(dev);
 152
 153         return regmap_update_bits(regmap, TMP103_CONF_REG,
 154                                   TMP103_CONF_SD_MASK, 0);
 155 }
 156
 157 static int __maybe_unused tmp103_resume(struct device *dev)
 158 {
 159         struct regmap *regmap = dev_get_drvdata(dev);
 160
 161         return regmap_update_bits(regmap, TMP103_CONF_REG,
 162                                   TMP103_CONF_SD_MASK, TMP103_CONF_SD);
 163 }
 164
 165 static SIMPLE_DEV_PM_OPS(tmp103_dev_pm_ops, tmp103_suspend, tmp103_resume);
 166
 167 static const struct i2c_device_id tmp103_id[] = {
 168         { "tmp103", 0 },
 169         { }
 170 };
 171 MODULE_DEVICE_TABLE(i2c, tmp103_id);
 172
 173 static const struct of_device_id tmp103_of_match[] = {
 174         { .compatible = "ti,tmp103" },
 175         { },
 176 };
 177 MODULE_DEVICE_TABLE(of, tmp103_of_match);
 178
 179 static struct i2c_driver tmp103_driver = {
 180         .driver = {
 181                 .name   = "tmp103",
 182                 .of_match_table = of_match_ptr(tmp103_of_match),
 183                 .pm     = &tmp103_dev_pm_ops,
 184         },
 185         .probe          = tmp103_probe,
 186         .id_table       = tmp103_id,
 187 };
 188
 189 module_i2c_driver(tmp103_driver);
 190
 191 MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
 192 MODULE_DESCRIPTION("Texas Instruments TMP103 temperature sensor driver");
 193 MODULE_LICENSE("GPL");