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
tmp117_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * channel,int * val,int * val2,long mask)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
tmp117_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * channel,int val,int val2,long mask)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
tmp117_probe(struct i2c_client * client)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