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"); 231