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/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 static int tmp117_read_raw(struct iio_dev *indio_dev, 46 struct iio_chan_spec const *channel, int *val, 47 int *val2, long mask) 48 { 49 struct tmp117_data *data = iio_priv(indio_dev); 50 s32 ret; 51 52 switch (mask) { 53 case IIO_CHAN_INFO_RAW: 54 ret = i2c_smbus_read_word_swapped(data->client, 55 TMP117_REG_TEMP); 56 if (ret < 0) 57 return ret; 58 *val = sign_extend32(ret, 15); 59 return IIO_VAL_INT; 60 61 case IIO_CHAN_INFO_CALIBBIAS: 62 ret = i2c_smbus_read_word_swapped(data->client, 63 TMP117_REG_TEMP_OFFSET); 64 if (ret < 0) 65 return ret; 66 *val = sign_extend32(ret, 15); 67 return IIO_VAL_INT; 68 69 case IIO_CHAN_INFO_SCALE: 70 /* 71 * Conversion from 10s of uC to mC 72 * as IIO reports temperature in mC 73 */ 74 *val = TMP117_RESOLUTION_10UC / MICRODEGREE_PER_10MILLIDEGREE; 75 *val2 = (TMP117_RESOLUTION_10UC % 76 MICRODEGREE_PER_10MILLIDEGREE) * 100; 77 78 return IIO_VAL_INT_PLUS_MICRO; 79 80 default: 81 return -EINVAL; 82 } 83 } 84 85 static int tmp117_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec 86 const *channel, int val, int val2, long mask) 87 { 88 struct tmp117_data *data = iio_priv(indio_dev); 89 s16 off; 90 91 switch (mask) { 92 case IIO_CHAN_INFO_CALIBBIAS: 93 off = clamp_t(int, val, S16_MIN, S16_MAX); 94 if (off == data->calibbias) 95 return 0; 96 data->calibbias = off; 97 return i2c_smbus_write_word_swapped(data->client, 98 TMP117_REG_TEMP_OFFSET, off); 99 100 default: 101 return -EINVAL; 102 } 103 } 104 105 static const struct iio_chan_spec tmp117_channels[] = { 106 { 107 .type = IIO_TEMP, 108 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 109 BIT(IIO_CHAN_INFO_CALIBBIAS) | 110 BIT(IIO_CHAN_INFO_SCALE), 111 }, 112 }; 113 114 static const struct iio_chan_spec tmp116_channels[] = { 115 { 116 .type = IIO_TEMP, 117 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 118 BIT(IIO_CHAN_INFO_SCALE), 119 }, 120 }; 121 122 static const struct iio_info tmp117_info = { 123 .read_raw = tmp117_read_raw, 124 .write_raw = tmp117_write_raw, 125 }; 126 127 static int tmp117_identify(struct i2c_client *client) 128 { 129 const struct i2c_device_id *id; 130 unsigned long match_data; 131 int dev_id; 132 133 dev_id = i2c_smbus_read_word_swapped(client, TMP117_REG_DEVICE_ID); 134 if (dev_id < 0) 135 return dev_id; 136 137 switch (dev_id) { 138 case TMP116_DEVICE_ID: 139 case TMP117_DEVICE_ID: 140 return dev_id; 141 } 142 143 dev_info(&client->dev, "Unknown device id (0x%x), use fallback compatible\n", 144 dev_id); 145 146 match_data = (uintptr_t)device_get_match_data(&client->dev); 147 if (match_data) 148 return match_data; 149 150 id = i2c_client_get_device_id(client); 151 if (id) 152 return id->driver_data; 153 154 dev_err(&client->dev, "Failed to identify unsupported device\n"); 155 156 return -ENODEV; 157 } 158 159 static int tmp117_probe(struct i2c_client *client) 160 { 161 struct tmp117_data *data; 162 struct iio_dev *indio_dev; 163 int ret, dev_id; 164 165 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) 166 return -EOPNOTSUPP; 167 168 ret = tmp117_identify(client); 169 if (ret < 0) 170 return ret; 171 172 dev_id = ret; 173 174 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); 175 if (!indio_dev) 176 return -ENOMEM; 177 178 data = iio_priv(indio_dev); 179 data->client = client; 180 data->calibbias = 0; 181 182 indio_dev->modes = INDIO_DIRECT_MODE; 183 indio_dev->info = &tmp117_info; 184 185 switch (dev_id) { 186 case TMP116_DEVICE_ID: 187 indio_dev->channels = tmp116_channels; 188 indio_dev->num_channels = ARRAY_SIZE(tmp116_channels); 189 indio_dev->name = "tmp116"; 190 break; 191 case TMP117_DEVICE_ID: 192 indio_dev->channels = tmp117_channels; 193 indio_dev->num_channels = ARRAY_SIZE(tmp117_channels); 194 indio_dev->name = "tmp117"; 195 break; 196 } 197 198 return devm_iio_device_register(&client->dev, indio_dev); 199 } 200 201 static const struct of_device_id tmp117_of_match[] = { 202 { .compatible = "ti,tmp116", .data = (void *)TMP116_DEVICE_ID }, 203 { .compatible = "ti,tmp117", .data = (void *)TMP117_DEVICE_ID }, 204 { } 205 }; 206 MODULE_DEVICE_TABLE(of, tmp117_of_match); 207 208 static const struct i2c_device_id tmp117_id[] = { 209 { "tmp116", TMP116_DEVICE_ID }, 210 { "tmp117", TMP117_DEVICE_ID }, 211 { } 212 }; 213 MODULE_DEVICE_TABLE(i2c, tmp117_id); 214 215 static struct i2c_driver tmp117_driver = { 216 .driver = { 217 .name = "tmp117", 218 .of_match_table = tmp117_of_match, 219 }, 220 .probe_new = tmp117_probe, 221 .id_table = tmp117_id, 222 }; 223 module_i2c_driver(tmp117_driver); 224 225 MODULE_AUTHOR("Puranjay Mohan <puranjay12@gmail.com>"); 226 MODULE_DESCRIPTION("TI TMP117 Temperature sensor driver"); 227 MODULE_LICENSE("GPL"); 228