drivers/iio/temperature/tmp117.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Digital temperature sensor with integrated Non-volatile memory
   4  * Copyright (c) 2021 Puranjay Mohan <[email protected]>
   5  *
   6  * Driver for the Texas Instruments TMP117 Temperature Sensor
   7  * (7-bit I2C slave address (0x48 - 0x4B), changeable via ADD pins)
   8  *
   9  * Note: This driver assumes that the sensor has been calibrated beforehand.
  10  */
  11
  12 #include <linux/err.h>
  13 #include <linux/i2c.h>
  14 #include <linux/module.h>
  15 #include <linux/bitops.h>
  16 #include <linux/types.h>
  17 #include <linux/kernel.h>
  18 #include <linux/limits.h>
  19 #include <linux/property.h>
  20
  21 #include <linux/iio/iio.h>
  22
  23 #define TMP117_REG_TEMP                 0x0
  24 #define TMP117_REG_CFGR                 0x1
  25 #define TMP117_REG_HIGH_LIM             0x2
  26 #define TMP117_REG_LOW_LIM              0x3
  27 #define TMP117_REG_EEPROM_UL            0x4
  28 #define TMP117_REG_EEPROM1              0x5
  29 #define TMP117_REG_EEPROM2              0x6
  30 #define TMP117_REG_TEMP_OFFSET          0x7
  31 #define TMP117_REG_EEPROM3              0x8
  32 #define TMP117_REG_DEVICE_ID            0xF
  33
  34 #define TMP117_RESOLUTION_10UC          78125
  35 #define MICRODEGREE_PER_10MILLIDEGREE   10000
  36
  37 #define TMP116_DEVICE_ID                0x1116
  38 #define TMP117_DEVICE_ID                0x0117
  39
  40 struct tmp117_data {
  41         struct i2c_client *client;
  42         s16 calibbias;
  43 };
  44
  45 struct tmp11x_info {
  46         const char *name;
  47         struct iio_chan_spec const *channels;
  48         int num_channels;
  49 };
  50
  51 static int tmp117_read_raw(struct iio_dev *indio_dev,
  52                            struct iio_chan_spec const *channel, int *val,
  53                            int *val2, long mask)
  54 {
  55         struct tmp117_data *data = iio_priv(indio_dev);
  56         s32 ret;
  57
  58         switch (mask) {
  59         case IIO_CHAN_INFO_RAW:
  60                 ret = i2c_smbus_read_word_swapped(data->client,
  61                                                   TMP117_REG_TEMP);
  62                 if (ret < 0)
  63                         return ret;
  64                 *val = sign_extend32(ret, 15);
  65                 return IIO_VAL_INT;
  66
  67         case IIO_CHAN_INFO_CALIBBIAS:
  68                 ret = i2c_smbus_read_word_swapped(data->client,
  69                                                   TMP117_REG_TEMP_OFFSET);
  70                 if (ret < 0)
  71                         return ret;
  72                 *val = sign_extend32(ret, 15);
  73                 return IIO_VAL_INT;
  74
  75         case IIO_CHAN_INFO_SCALE:
  76                 /*
  77                  * Conversion from 10s of uC to mC
  78                  * as IIO reports temperature in mC
  79                  */
  80                 *val = TMP117_RESOLUTION_10UC / MICRODEGREE_PER_10MILLIDEGREE;
  81                 *val2 = (TMP117_RESOLUTION_10UC %
  82                                         MICRODEGREE_PER_10MILLIDEGREE) * 100;
  83
  84                 return IIO_VAL_INT_PLUS_MICRO;
  85
  86         default:
  87                 return -EINVAL;
  88         }
  89 }
  90
  91 static int tmp117_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec
  92                             const *channel, int val, int val2, long mask)
  93 {
  94         struct tmp117_data *data = iio_priv(indio_dev);
  95         s16 off;
  96
  97         switch (mask) {
  98         case IIO_CHAN_INFO_CALIBBIAS:
  99                 off = clamp_t(int, val, S16_MIN, S16_MAX);
 100                 if (off == data->calibbias)
 101                         return 0;
 102                 data->calibbias = off;
 103                 return i2c_smbus_write_word_swapped(data->client,
 104                                                 TMP117_REG_TEMP_OFFSET, off);
 105
 106         default:
 107                 return -EINVAL;
 108         }
 109 }
 110
 111 static const struct iio_chan_spec tmp117_channels[] = {
 112         {
 113                 .type = IIO_TEMP,
 114                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 115                                       BIT(IIO_CHAN_INFO_CALIBBIAS) |
 116                                       BIT(IIO_CHAN_INFO_SCALE),
 117         },
 118 };
 119
 120 static const struct iio_chan_spec tmp116_channels[] = {
 121         {
 122                 .type = IIO_TEMP,
 123                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 124                                       BIT(IIO_CHAN_INFO_SCALE),
 125         },
 126 };
 127
 128 static const struct tmp11x_info tmp116_channels_info = {
 129         .name = "tmp116",
 130         .channels = tmp116_channels,
 131         .num_channels = ARRAY_SIZE(tmp116_channels)
 132 };
 133
 134 static const struct tmp11x_info tmp117_channels_info = {
 135         .name = "tmp117",
 136         .channels = tmp117_channels,
 137         .num_channels = ARRAY_SIZE(tmp117_channels)
 138 };
 139
 140 static const struct iio_info tmp117_info = {
 141         .read_raw = tmp117_read_raw,
 142         .write_raw = tmp117_write_raw,
 143 };
 144
 145 static int tmp117_probe(struct i2c_client *client)
 146 {
 147         const struct tmp11x_info *match_data;
 148         struct tmp117_data *data;
 149         struct iio_dev *indio_dev;
 150         int dev_id;
 151
 152         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
 153                 return -EOPNOTSUPP;
 154
 155         dev_id = i2c_smbus_read_word_swapped(client, TMP117_REG_DEVICE_ID);
 156         if (dev_id < 0)
 157                 return dev_id;
 158
 159         switch (dev_id) {
 160         case TMP116_DEVICE_ID:
 161                 match_data = &tmp116_channels_info;
 162                 break;
 163         case TMP117_DEVICE_ID:
 164                 match_data = &tmp117_channels_info;
 165                 break;
 166         default:
 167                 dev_info(&client->dev,
 168                          "Unknown device id (0x%x), use fallback compatible\n",
 169                          dev_id);
 170                 match_data = i2c_get_match_data(client);
 171         }
 172
 173         if (!match_data)
 174                 return dev_err_probe(&client->dev, -ENODEV,
 175                                      "Failed to identify unsupported device\n");
 176
 177         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 178         if (!indio_dev)
 179                 return -ENOMEM;
 180
 181         data = iio_priv(indio_dev);
 182         data->client = client;
 183         data->calibbias = 0;
 184
 185         indio_dev->modes = INDIO_DIRECT_MODE;
 186         indio_dev->info = &tmp117_info;
 187         indio_dev->channels = match_data->channels;
 188         indio_dev->num_channels = match_data->num_channels;
 189         indio_dev->name = match_data->name;
 190
 191
 192         return devm_iio_device_register(&client->dev, indio_dev);
 193 }
 194
 195 static const struct of_device_id tmp117_of_match[] = {
 196         { .compatible = "ti,tmp116", .data = &tmp116_channels_info },
 197         { .compatible = "ti,tmp117", .data = &tmp117_channels_info },
 198         { }
 199 };
 200 MODULE_DEVICE_TABLE(of, tmp117_of_match);
 201
 202 static const struct i2c_device_id tmp117_id[] = {
 203         { "tmp116", (kernel_ulong_t)&tmp116_channels_info },
 204         { "tmp117", (kernel_ulong_t)&tmp117_channels_info },
 205         { }
 206 };
 207 MODULE_DEVICE_TABLE(i2c, tmp117_id);
 208
 209 static struct i2c_driver tmp117_driver = {
 210         .driver = {
 211                 .name   = "tmp117",
 212                 .of_match_table = tmp117_of_match,
 213         },
 214         .probe          = tmp117_probe,
 215         .id_table       = tmp117_id,
 216 };
 217 module_i2c_driver(tmp117_driver);
 218
 219 MODULE_AUTHOR("Puranjay Mohan <[email protected]>");
 220 MODULE_DESCRIPTION("TI TMP117 Temperature sensor driver");
 221 MODULE_LICENSE("GPL");