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 <puranjay12@gmail.com>
   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/delay.h>
  13 #include <linux/err.h>
  14 #include <linux/i2c.h>
  15 #include <linux/module.h>
  16 #include <linux/bitops.h>
  17 #include <linux/types.h>
  18 #include <linux/kernel.h>
  19 #include <linux/limits.h>
  20 #include <linux/property.h>
  21 #include <linux/regulator/consumer.h>
  22
  23 #include <linux/iio/iio.h>
  24
  25 #define TMP117_REG_TEMP                 0x0
  26 #define TMP117_REG_CFGR                 0x1
  27 #define TMP117_REG_HIGH_LIM             0x2
  28 #define TMP117_REG_LOW_LIM              0x3
  29 #define TMP117_REG_EEPROM_UL            0x4
  30 #define TMP117_REG_EEPROM1              0x5
  31 #define TMP117_REG_EEPROM2              0x6
  32 #define TMP117_REG_TEMP_OFFSET          0x7
  33 #define TMP117_REG_EEPROM3              0x8
  34 #define TMP117_REG_DEVICE_ID            0xF
  35
  36 #define TMP117_RESOLUTION_10UC          78125
  37 #define MICRODEGREE_PER_10MILLIDEGREE   10000
  38
  39 #define TMP116_DEVICE_ID                0x1116
  40 #define TMP117_DEVICE_ID                0x0117
  41
  42 struct tmp117_data {
  43         struct i2c_client *client;
  44         s16 calibbias;
  45 };
  46
  47 struct tmp11x_info {
  48         const char *name;
  49         struct iio_chan_spec const *channels;
  50         int num_channels;
  51 };
  52
  53 static int tmp117_read_raw(struct iio_dev *indio_dev,
  54                            struct iio_chan_spec const *channel, int *val,
  55                            int *val2, long mask)
  56 {
  57         struct tmp117_data *data = iio_priv(indio_dev);
  58         s32 ret;
  59
  60         switch (mask) {
  61         case IIO_CHAN_INFO_RAW:
  62                 ret = i2c_smbus_read_word_swapped(data->client,
  63                                                   TMP117_REG_TEMP);
  64                 if (ret < 0)
  65                         return ret;
  66                 *val = sign_extend32(ret, 15);
  67                 return IIO_VAL_INT;
  68
  69         case IIO_CHAN_INFO_CALIBBIAS:
  70                 ret = i2c_smbus_read_word_swapped(data->client,
  71                                                   TMP117_REG_TEMP_OFFSET);
  72                 if (ret < 0)
  73                         return ret;
  74                 *val = sign_extend32(ret, 15);
  75                 return IIO_VAL_INT;
  76
  77         case IIO_CHAN_INFO_SCALE:
  78                 /*
  79                  * Conversion from 10s of uC to mC
  80                  * as IIO reports temperature in mC
  81                  */
  82                 *val = TMP117_RESOLUTION_10UC / MICRODEGREE_PER_10MILLIDEGREE;
  83                 *val2 = (TMP117_RESOLUTION_10UC %
  84                                         MICRODEGREE_PER_10MILLIDEGREE) * 100;
  85
  86                 return IIO_VAL_INT_PLUS_MICRO;
  87
  88         default:
  89                 return -EINVAL;
  90         }
  91 }
  92
  93 static int tmp117_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec
  94                             const *channel, int val, int val2, long mask)
  95 {
  96         struct tmp117_data *data = iio_priv(indio_dev);
  97         s16 off;
  98
  99         switch (mask) {
 100         case IIO_CHAN_INFO_CALIBBIAS:
 101                 off = clamp_t(int, val, S16_MIN, S16_MAX);
 102                 if (off == data->calibbias)
 103                         return 0;
 104                 data->calibbias = off;
 105                 return i2c_smbus_write_word_swapped(data->client,
 106                                                 TMP117_REG_TEMP_OFFSET, off);
 107
 108         default:
 109                 return -EINVAL;
 110         }
 111 }
 112
 113 static const struct iio_chan_spec tmp117_channels[] = {
 114         {
 115                 .type = IIO_TEMP,
 116                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 117                                       BIT(IIO_CHAN_INFO_CALIBBIAS) |
 118                                       BIT(IIO_CHAN_INFO_SCALE),
 119         },
 120 };
 121
 122 static const struct iio_chan_spec tmp116_channels[] = {
 123         {
 124                 .type = IIO_TEMP,
 125                 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
 126                                       BIT(IIO_CHAN_INFO_SCALE),
 127         },
 128 };
 129
 130 static const struct tmp11x_info tmp116_channels_info = {
 131         .name = "tmp116",
 132         .channels = tmp116_channels,
 133         .num_channels = ARRAY_SIZE(tmp116_channels)
 134 };
 135
 136 static const struct tmp11x_info tmp117_channels_info = {
 137         .name = "tmp117",
 138         .channels = tmp117_channels,
 139         .num_channels = ARRAY_SIZE(tmp117_channels)
 140 };
 141
 142 static const struct iio_info tmp117_info = {
 143         .read_raw = tmp117_read_raw,
 144         .write_raw = tmp117_write_raw,
 145 };
 146
 147 static int tmp117_probe(struct i2c_client *client)
 148 {
 149         const struct tmp11x_info *match_data;
 150         struct tmp117_data *data;
 151         struct iio_dev *indio_dev;
 152         int dev_id;
 153         int ret;
 154
 155         if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
 156                 return -EOPNOTSUPP;
 157
 158         ret = devm_regulator_get_enable(&client->dev, "vcc");
 159         if (ret)
 160                 return ret;
 161
 162         fsleep(1500);
 163
 164         dev_id = i2c_smbus_read_word_swapped(client, TMP117_REG_DEVICE_ID);
 165         if (dev_id < 0)
 166                 return dev_id;
 167
 168         switch (dev_id) {
 169         case TMP116_DEVICE_ID:
 170                 match_data = &tmp116_channels_info;
 171                 break;
 172         case TMP117_DEVICE_ID:
 173                 match_data = &tmp117_channels_info;
 174                 break;
 175         default:
 176                 dev_info(&client->dev,
 177                          "Unknown device id (0x%x), use fallback compatible\n",
 178                          dev_id);
 179                 match_data = i2c_get_match_data(client);
 180         }
 181
 182         if (!match_data)
 183                 return dev_err_probe(&client->dev, -ENODEV,
 184                                      "Failed to identify unsupported device\n");
 185
 186         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 187         if (!indio_dev)
 188                 return -ENOMEM;
 189
 190         data = iio_priv(indio_dev);
 191         data->client = client;
 192         data->calibbias = 0;
 193
 194         indio_dev->modes = INDIO_DIRECT_MODE;
 195         indio_dev->info = &tmp117_info;
 196         indio_dev->channels = match_data->channels;
 197         indio_dev->num_channels = match_data->num_channels;
 198         indio_dev->name = match_data->name;
 199
 200
 201         return devm_iio_device_register(&client->dev, indio_dev);
 202 }
 203
 204 static const struct of_device_id tmp117_of_match[] = {
 205         { .compatible = "ti,tmp116", .data = &tmp116_channels_info },
 206         { .compatible = "ti,tmp117", .data = &tmp117_channels_info },
 207         { }
 208 };
 209 MODULE_DEVICE_TABLE(of, tmp117_of_match);
 210
 211 static const struct i2c_device_id tmp117_id[] = {
 212         { "tmp116", (kernel_ulong_t)&tmp116_channels_info },
 213         { "tmp117", (kernel_ulong_t)&tmp117_channels_info },
 214         { }
 215 };
 216 MODULE_DEVICE_TABLE(i2c, tmp117_id);
 217
 218 static struct i2c_driver tmp117_driver = {
 219         .driver = {
 220                 .name   = "tmp117",
 221                 .of_match_table = tmp117_of_match,
 222         },
 223         .probe          = tmp117_probe,
 224         .id_table       = tmp117_id,
 225 };
 226 module_i2c_driver(tmp117_driver);
 227
 228 MODULE_AUTHOR("Puranjay Mohan <puranjay12@gmail.com>");
 229 MODULE_DESCRIPTION("TI TMP117 Temperature sensor driver");
 230 MODULE_LICENSE("GPL");