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_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
  80 static 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
  97 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp103_show_temp, NULL ,
  98                           TMP103_TEMP_REG);
  99
 100 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, tmp103_show_temp,
 101                           tmp103_set_temp, TMP103_TLOW_REG);
 102
 103 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp103_show_temp,
 104                           tmp103_set_temp, TMP103_THIGH_REG);
 105
 106 static 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 };
 112 ATTRIBUTE_GROUPS(tmp103);
 113
 114 static bool tmp103_regmap_is_volatile(struct device *dev, unsigned int reg)
 115 {
 116         return reg == TMP103_TEMP_REG;
 117 }
 118
 119 static 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
 126 static 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
 153 #ifdef CONFIG_PM
 154 static int tmp103_suspend(struct device *dev)
 155 {
 156         struct regmap *regmap = dev_get_drvdata(dev);
 157
 158         return regmap_update_bits(regmap, TMP103_CONF_REG,
 159                                   TMP103_CONF_SD_MASK, 0);
 160 }
 161
 162 static int tmp103_resume(struct device *dev)
 163 {
 164         struct regmap *regmap = dev_get_drvdata(dev);
 165
 166         return regmap_update_bits(regmap, TMP103_CONF_REG,
 167                                   TMP103_CONF_SD_MASK, TMP103_CONF_SD);
 168 }
 169
 170 static const struct dev_pm_ops tmp103_dev_pm_ops = {
 171         .suspend        = tmp103_suspend,
 172         .resume         = tmp103_resume,
 173 };
 174
 175 #define TMP103_DEV_PM_OPS (&tmp103_dev_pm_ops)
 176 #else
 177 #define TMP103_DEV_PM_OPS NULL
 178 #endif /* CONFIG_PM */
 179
 180 static const struct i2c_device_id tmp103_id[] = {
 181         { "tmp103", 0 },
 182         { }
 183 };
 184 MODULE_DEVICE_TABLE(i2c, tmp103_id);
 185
 186 static struct i2c_driver tmp103_driver = {
 187         .driver = {
 188                 .name   = "tmp103",
 189                 .pm     = TMP103_DEV_PM_OPS,
 190         },
 191         .probe          = tmp103_probe,
 192         .id_table       = tmp103_id,
 193 };
 194
 195 module_i2c_driver(tmp103_driver);
 196
 197 MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
 198 MODULE_DESCRIPTION("Texas Instruments TMP103 temperature sensor driver");
 199 MODULE_LICENSE("GPL");