Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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linux
1/*
2 * tmp006.c - Support for TI TMP006 IR thermopile sensor
3 *
4 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
5 *
6 * This file is subject to the terms and conditions of version 2 of
7 * the GNU General Public License. See the file COPYING in the main
8 * directory of this archive for more details.
9 *
10 * Driver for the Texas Instruments I2C 16-bit IR thermopile sensor
11 *
12 * (7-bit I2C slave address 0x40, changeable via ADR pins)
13 *
14 * TODO: data ready irq
15 */
16
17#include <linux/err.h>
18#include <linux/i2c.h>
19#include <linux/delay.h>
20#include <linux/module.h>
21#include <linux/pm.h>
22#include <linux/bitops.h>
23
24#include <linux/iio/iio.h>
25#include <linux/iio/sysfs.h>
26
27#define TMP006_VOBJECT 0x00
28#define TMP006_TAMBIENT 0x01
29#define TMP006_CONFIG 0x02
30#define TMP006_MANUFACTURER_ID 0xfe
31#define TMP006_DEVICE_ID 0xff
32
33#define TMP006_TAMBIENT_SHIFT 2
34
35#define TMP006_CONFIG_RESET BIT(15)
36#define TMP006_CONFIG_DRDY_EN BIT(8)
37#define TMP006_CONFIG_DRDY BIT(7)
38
39#define TMP006_CONFIG_MOD_MASK 0x7000
40
41#define TMP006_CONFIG_CR_MASK 0x0e00
42#define TMP006_CONFIG_CR_SHIFT 9
43
44#define MANUFACTURER_MAGIC 0x5449
45#define DEVICE_MAGIC 0x0067
46
47struct tmp006_data {
48 struct i2c_client *client;
49 u16 config;
50};
51
52static int tmp006_read_measurement(struct tmp006_data *data, u8 reg)
53{
54 s32 ret;
55 int tries = 50;
56
57 while (tries-- > 0) {
58 ret = i2c_smbus_read_word_swapped(data->client,
59 TMP006_CONFIG);
60 if (ret < 0)
61 return ret;
62 if (ret & TMP006_CONFIG_DRDY)
63 break;
64 msleep(100);
65 }
66
67 if (tries < 0)
68 return -EIO;
69
70 return i2c_smbus_read_word_swapped(data->client, reg);
71}
72
73static const int tmp006_freqs[5][2] = { {4, 0}, {2, 0}, {1, 0},
74 {0, 500000}, {0, 250000} };
75
76static int tmp006_read_raw(struct iio_dev *indio_dev,
77 struct iio_chan_spec const *channel, int *val,
78 int *val2, long mask)
79{
80 struct tmp006_data *data = iio_priv(indio_dev);
81 s32 ret;
82 int cr;
83
84 switch (mask) {
85 case IIO_CHAN_INFO_RAW:
86 if (channel->type == IIO_VOLTAGE) {
87 /* LSB is 156.25 nV */
88 ret = tmp006_read_measurement(data, TMP006_VOBJECT);
89 if (ret < 0)
90 return ret;
91 *val = sign_extend32(ret, 15);
92 } else if (channel->type == IIO_TEMP) {
93 /* LSB is 0.03125 degrees Celsius */
94 ret = tmp006_read_measurement(data, TMP006_TAMBIENT);
95 if (ret < 0)
96 return ret;
97 *val = sign_extend32(ret, 15) >> TMP006_TAMBIENT_SHIFT;
98 } else {
99 break;
100 }
101 return IIO_VAL_INT;
102 case IIO_CHAN_INFO_SCALE:
103 if (channel->type == IIO_VOLTAGE) {
104 *val = 0;
105 *val2 = 156250;
106 } else if (channel->type == IIO_TEMP) {
107 *val = 31;
108 *val2 = 250000;
109 } else {
110 break;
111 }
112 return IIO_VAL_INT_PLUS_MICRO;
113 case IIO_CHAN_INFO_SAMP_FREQ:
114 cr = (data->config & TMP006_CONFIG_CR_MASK)
115 >> TMP006_CONFIG_CR_SHIFT;
116 *val = tmp006_freqs[cr][0];
117 *val2 = tmp006_freqs[cr][1];
118 return IIO_VAL_INT_PLUS_MICRO;
119 default:
120 break;
121 }
122
123 return -EINVAL;
124}
125
126static int tmp006_write_raw(struct iio_dev *indio_dev,
127 struct iio_chan_spec const *chan,
128 int val,
129 int val2,
130 long mask)
131{
132 struct tmp006_data *data = iio_priv(indio_dev);
133 int i;
134
135 for (i = 0; i < ARRAY_SIZE(tmp006_freqs); i++)
136 if ((val == tmp006_freqs[i][0]) &&
137 (val2 == tmp006_freqs[i][1])) {
138 data->config &= ~TMP006_CONFIG_CR_MASK;
139 data->config |= i << TMP006_CONFIG_CR_SHIFT;
140
141 return i2c_smbus_write_word_swapped(data->client,
142 TMP006_CONFIG,
143 data->config);
144
145 }
146 return -EINVAL;
147}
148
149static IIO_CONST_ATTR(sampling_frequency_available, "4 2 1 0.5 0.25");
150
151static struct attribute *tmp006_attributes[] = {
152 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
153 NULL
154};
155
156static const struct attribute_group tmp006_attribute_group = {
157 .attrs = tmp006_attributes,
158};
159
160static const struct iio_chan_spec tmp006_channels[] = {
161 {
162 .type = IIO_VOLTAGE,
163 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
164 BIT(IIO_CHAN_INFO_SCALE),
165 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
166 },
167 {
168 .type = IIO_TEMP,
169 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
170 BIT(IIO_CHAN_INFO_SCALE),
171 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
172 }
173};
174
175static const struct iio_info tmp006_info = {
176 .read_raw = tmp006_read_raw,
177 .write_raw = tmp006_write_raw,
178 .attrs = &tmp006_attribute_group,
179 .driver_module = THIS_MODULE,
180};
181
182static bool tmp006_check_identification(struct i2c_client *client)
183{
184 int mid, did;
185
186 mid = i2c_smbus_read_word_swapped(client, TMP006_MANUFACTURER_ID);
187 if (mid < 0)
188 return false;
189
190 did = i2c_smbus_read_word_swapped(client, TMP006_DEVICE_ID);
191 if (did < 0)
192 return false;
193
194 return mid == MANUFACTURER_MAGIC && did == DEVICE_MAGIC;
195}
196
197static int tmp006_probe(struct i2c_client *client,
198 const struct i2c_device_id *id)
199{
200 struct iio_dev *indio_dev;
201 struct tmp006_data *data;
202 int ret;
203
204 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
205 return -ENODEV;
206
207 if (!tmp006_check_identification(client)) {
208 dev_err(&client->dev, "no TMP006 sensor\n");
209 return -ENODEV;
210 }
211
212 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
213 if (!indio_dev)
214 return -ENOMEM;
215
216 data = iio_priv(indio_dev);
217 i2c_set_clientdata(client, indio_dev);
218 data->client = client;
219
220 indio_dev->dev.parent = &client->dev;
221 indio_dev->name = dev_name(&client->dev);
222 indio_dev->modes = INDIO_DIRECT_MODE;
223 indio_dev->info = &tmp006_info;
224
225 indio_dev->channels = tmp006_channels;
226 indio_dev->num_channels = ARRAY_SIZE(tmp006_channels);
227
228 ret = i2c_smbus_read_word_swapped(data->client, TMP006_CONFIG);
229 if (ret < 0)
230 return ret;
231 data->config = ret;
232
233 return iio_device_register(indio_dev);
234}
235
236static int tmp006_powerdown(struct tmp006_data *data)
237{
238 return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
239 data->config & ~TMP006_CONFIG_MOD_MASK);
240}
241
242static int tmp006_remove(struct i2c_client *client)
243{
244 struct iio_dev *indio_dev = i2c_get_clientdata(client);
245
246 iio_device_unregister(indio_dev);
247 tmp006_powerdown(iio_priv(indio_dev));
248
249 return 0;
250}
251
252#ifdef CONFIG_PM_SLEEP
253static int tmp006_suspend(struct device *dev)
254{
255 struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
256 return tmp006_powerdown(iio_priv(indio_dev));
257}
258
259static int tmp006_resume(struct device *dev)
260{
261 struct tmp006_data *data = iio_priv(i2c_get_clientdata(
262 to_i2c_client(dev)));
263 return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,
264 data->config | TMP006_CONFIG_MOD_MASK);
265}
266#endif
267
268static SIMPLE_DEV_PM_OPS(tmp006_pm_ops, tmp006_suspend, tmp006_resume);
269
270static const struct i2c_device_id tmp006_id[] = {
271 { "tmp006", 0 },
272 { }
273};
274MODULE_DEVICE_TABLE(i2c, tmp006_id);
275
276static struct i2c_driver tmp006_driver = {
277 .driver = {
278 .name = "tmp006",
279 .pm = &tmp006_pm_ops,
280 .owner = THIS_MODULE,
281 },
282 .probe = tmp006_probe,
283 .remove = tmp006_remove,
284 .id_table = tmp006_id,
285};
286module_i2c_driver(tmp006_driver);
287
288MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
289MODULE_DESCRIPTION("TI TMP006 IR thermopile sensor driver");
290MODULE_LICENSE("GPL");