Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[deliverable/linux.git] / drivers / iio / magnetometer / mag3110.c
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1/*
2 * mag3110.c - Support for Freescale MAG3110 magnetometer 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 * (7-bit I2C slave address 0x0e)
11 *
12 * TODO: irq, user offset, oversampling, continuous mode
13 */
14
15#include <linux/module.h>
16#include <linux/i2c.h>
17#include <linux/iio/iio.h>
18#include <linux/iio/sysfs.h>
19#include <linux/iio/trigger_consumer.h>
20#include <linux/iio/buffer.h>
21#include <linux/iio/triggered_buffer.h>
22#include <linux/delay.h>
23
24#define MAG3110_STATUS 0x00
25#define MAG3110_OUT_X 0x01 /* MSB first */
26#define MAG3110_OUT_Y 0x03
27#define MAG3110_OUT_Z 0x05
28#define MAG3110_WHO_AM_I 0x07
29#define MAG3110_OFF_X 0x09 /* MSB first */
30#define MAG3110_OFF_Y 0x0b
31#define MAG3110_OFF_Z 0x0d
32#define MAG3110_DIE_TEMP 0x0f
33#define MAG3110_CTRL_REG1 0x10
34#define MAG3110_CTRL_REG2 0x11
35
36#define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
37
38#define MAG3110_CTRL_DR_MASK (BIT(7) | BIT(6) | BIT(5))
39#define MAG3110_CTRL_DR_SHIFT 5
40#define MAG3110_CTRL_DR_DEFAULT 0
41
42#define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */
43#define MAG3110_CTRL_AC BIT(0) /* continuous measurements */
44
45#define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */
46#define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */
47
48#define MAG3110_DEVICE_ID 0xc4
49
50/* Each client has this additional data */
51struct mag3110_data {
52 struct i2c_client *client;
53 struct mutex lock;
54 u8 ctrl_reg1;
55};
56
57static int mag3110_request(struct mag3110_data *data)
58{
59 int ret, tries = 150;
60
61 /* trigger measurement */
62 ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
63 data->ctrl_reg1 | MAG3110_CTRL_TM);
64 if (ret < 0)
65 return ret;
66
67 while (tries-- > 0) {
68 ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);
69 if (ret < 0)
70 return ret;
71 /* wait for data ready */
72 if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)
73 break;
74 msleep(20);
75 }
76
77 if (tries < 0) {
78 dev_err(&data->client->dev, "data not ready\n");
79 return -EIO;
80 }
81
82 return 0;
83}
84
85static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
86{
87 int ret;
88
89 mutex_lock(&data->lock);
90 ret = mag3110_request(data);
91 if (ret < 0) {
92 mutex_unlock(&data->lock);
93 return ret;
94 }
95 ret = i2c_smbus_read_i2c_block_data(data->client,
96 MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf);
97 mutex_unlock(&data->lock);
98
99 return ret;
100}
101
102static ssize_t mag3110_show_int_plus_micros(char *buf,
103 const int (*vals)[2], int n)
104{
105 size_t len = 0;
106
107 while (n-- > 0)
108 len += scnprintf(buf + len, PAGE_SIZE - len,
71bd8945 109 "%d.%06d ", vals[n][0], vals[n][1]);
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110
111 /* replace trailing space by newline */
112 buf[len - 1] = '\n';
113
114 return len;
115}
116
117static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,
118 int val, int val2)
119{
120 while (n-- > 0)
121 if (val == vals[n][0] && val2 == vals[n][1])
122 return n;
123
124 return -EINVAL;
125}
126
127static const int mag3110_samp_freq[8][2] = {
128 {80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},
129 {1, 250000}, {0, 625000}
130};
131
132static ssize_t mag3110_show_samp_freq_avail(struct device *dev,
133 struct device_attribute *attr, char *buf)
134{
135 return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8);
136}
137
138static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail);
139
140static int mag3110_get_samp_freq_index(struct mag3110_data *data,
141 int val, int val2)
142{
143 return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val,
144 val2);
145}
146
147static int mag3110_read_raw(struct iio_dev *indio_dev,
148 struct iio_chan_spec const *chan,
149 int *val, int *val2, long mask)
150{
151 struct mag3110_data *data = iio_priv(indio_dev);
152 __be16 buffer[3];
153 int i, ret;
154
155 switch (mask) {
156 case IIO_CHAN_INFO_RAW:
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157 if (iio_buffer_enabled(indio_dev))
158 return -EBUSY;
159
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160 switch (chan->type) {
161 case IIO_MAGN: /* in 0.1 uT / LSB */
162 ret = mag3110_read(data, buffer);
163 if (ret < 0)
164 return ret;
165 *val = sign_extend32(
166 be16_to_cpu(buffer[chan->scan_index]), 15);
167 return IIO_VAL_INT;
168 case IIO_TEMP: /* in 1 C / LSB */
169 mutex_lock(&data->lock);
170 ret = mag3110_request(data);
171 if (ret < 0) {
172 mutex_unlock(&data->lock);
173 return ret;
174 }
175 ret = i2c_smbus_read_byte_data(data->client,
176 MAG3110_DIE_TEMP);
177 mutex_unlock(&data->lock);
178 if (ret < 0)
179 return ret;
180 *val = sign_extend32(ret, 7);
181 return IIO_VAL_INT;
182 default:
183 return -EINVAL;
184 }
185 case IIO_CHAN_INFO_SCALE:
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186 switch (chan->type) {
187 case IIO_MAGN:
188 *val = 0;
189 *val2 = 1000;
190 return IIO_VAL_INT_PLUS_MICRO;
191 case IIO_TEMP:
192 *val = 1000;
193 return IIO_VAL_INT;
194 default:
195 return -EINVAL;
196 }
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197 case IIO_CHAN_INFO_SAMP_FREQ:
198 i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
199 *val = mag3110_samp_freq[i][0];
200 *val2 = mag3110_samp_freq[i][1];
201 return IIO_VAL_INT_PLUS_MICRO;
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202 case IIO_CHAN_INFO_CALIBBIAS:
203 ret = i2c_smbus_read_word_swapped(data->client,
204 MAG3110_OFF_X + 2 * chan->scan_index);
205 if (ret < 0)
206 return ret;
207 *val = sign_extend32(ret >> 1, 14);
208 return IIO_VAL_INT;
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209 }
210 return -EINVAL;
211}
212
213static int mag3110_write_raw(struct iio_dev *indio_dev,
214 struct iio_chan_spec const *chan,
215 int val, int val2, long mask)
216{
217 struct mag3110_data *data = iio_priv(indio_dev);
218 int rate;
219
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220 if (iio_buffer_enabled(indio_dev))
221 return -EBUSY;
222
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223 switch (mask) {
224 case IIO_CHAN_INFO_SAMP_FREQ:
225 rate = mag3110_get_samp_freq_index(data, val, val2);
226 if (rate < 0)
227 return -EINVAL;
228
229 data->ctrl_reg1 &= ~MAG3110_CTRL_DR_MASK;
230 data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;
231 return i2c_smbus_write_byte_data(data->client,
232 MAG3110_CTRL_REG1, data->ctrl_reg1);
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233 case IIO_CHAN_INFO_CALIBBIAS:
234 if (val < -10000 || val > 10000)
235 return -EINVAL;
236 return i2c_smbus_write_word_swapped(data->client,
237 MAG3110_OFF_X + 2 * chan->scan_index, val << 1);
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238 default:
239 return -EINVAL;
240 }
241}
242
243static irqreturn_t mag3110_trigger_handler(int irq, void *p)
244{
245 struct iio_poll_func *pf = p;
246 struct iio_dev *indio_dev = pf->indio_dev;
247 struct mag3110_data *data = iio_priv(indio_dev);
248 u8 buffer[16]; /* 3 16-bit channels + 1 byte temp + padding + ts */
249 int ret;
250
251 ret = mag3110_read(data, (__be16 *) buffer);
252 if (ret < 0)
253 goto done;
254
255 if (test_bit(3, indio_dev->active_scan_mask)) {
256 ret = i2c_smbus_read_byte_data(data->client,
257 MAG3110_DIE_TEMP);
258 if (ret < 0)
259 goto done;
260 buffer[6] = ret;
261 }
262
263 iio_push_to_buffers_with_timestamp(indio_dev, buffer,
264 iio_get_time_ns());
265
266done:
267 iio_trigger_notify_done(indio_dev->trig);
268 return IRQ_HANDLED;
269}
270
271#define MAG3110_CHANNEL(axis, idx) { \
272 .type = IIO_MAGN, \
273 .modified = 1, \
274 .channel2 = IIO_MOD_##axis, \
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275 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
276 BIT(IIO_CHAN_INFO_CALIBBIAS), \
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277 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
278 BIT(IIO_CHAN_INFO_SCALE), \
279 .scan_index = idx, \
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280 .scan_type = { \
281 .sign = 's', \
282 .realbits = 16, \
283 .storagebits = 16, \
284 .endianness = IIO_BE, \
285 }, \
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286}
287
288static const struct iio_chan_spec mag3110_channels[] = {
289 MAG3110_CHANNEL(X, 0),
290 MAG3110_CHANNEL(Y, 1),
291 MAG3110_CHANNEL(Z, 2),
292 {
293 .type = IIO_TEMP,
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294 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
295 BIT(IIO_CHAN_INFO_SCALE),
39631b5f 296 .scan_index = 3,
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297 .scan_type = {
298 .sign = 's',
299 .realbits = 8,
300 .storagebits = 8,
301 },
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302 },
303 IIO_CHAN_SOFT_TIMESTAMP(4),
304};
305
306static struct attribute *mag3110_attributes[] = {
307 &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
308 NULL
309};
310
311static const struct attribute_group mag3110_group = {
312 .attrs = mag3110_attributes,
313};
314
315static const struct iio_info mag3110_info = {
316 .attrs = &mag3110_group,
317 .read_raw = &mag3110_read_raw,
318 .write_raw = &mag3110_write_raw,
319 .driver_module = THIS_MODULE,
320};
321
322static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0};
323
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324static int mag3110_standby(struct mag3110_data *data)
325{
326 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
327 data->ctrl_reg1 & ~MAG3110_CTRL_AC);
328}
329
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330static int mag3110_probe(struct i2c_client *client,
331 const struct i2c_device_id *id)
332{
333 struct mag3110_data *data;
334 struct iio_dev *indio_dev;
335 int ret;
336
337 ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I);
338 if (ret < 0)
339 return ret;
340 if (ret != MAG3110_DEVICE_ID)
341 return -ENODEV;
342
343 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
344 if (!indio_dev)
345 return -ENOMEM;
346
347 data = iio_priv(indio_dev);
348 data->client = client;
349 mutex_init(&data->lock);
350
351 i2c_set_clientdata(client, indio_dev);
352 indio_dev->info = &mag3110_info;
353 indio_dev->name = id->name;
354 indio_dev->dev.parent = &client->dev;
355 indio_dev->modes = INDIO_DIRECT_MODE;
356 indio_dev->channels = mag3110_channels;
357 indio_dev->num_channels = ARRAY_SIZE(mag3110_channels);
358 indio_dev->available_scan_masks = mag3110_scan_masks;
359
6584891b 360 data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT << MAG3110_CTRL_DR_SHIFT;
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361 ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG1,
362 data->ctrl_reg1);
363 if (ret < 0)
364 return ret;
365
366 ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2,
0828eddc 367 MAG3110_CTRL_AUTO_MRST_EN);
39631b5f 368 if (ret < 0)
66687e6a 369 goto standby_on_error;
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370
371 ret = iio_triggered_buffer_setup(indio_dev, NULL,
372 mag3110_trigger_handler, NULL);
373 if (ret < 0)
66687e6a 374 goto standby_on_error;
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375
376 ret = iio_device_register(indio_dev);
377 if (ret < 0)
378 goto buffer_cleanup;
379 return 0;
380
381buffer_cleanup:
382 iio_triggered_buffer_cleanup(indio_dev);
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383standby_on_error:
384 mag3110_standby(iio_priv(indio_dev));
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385 return ret;
386}
387
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388static int mag3110_remove(struct i2c_client *client)
389{
390 struct iio_dev *indio_dev = i2c_get_clientdata(client);
391
392 iio_device_unregister(indio_dev);
393 iio_triggered_buffer_cleanup(indio_dev);
394 mag3110_standby(iio_priv(indio_dev));
395
396 return 0;
397}
398
399#ifdef CONFIG_PM_SLEEP
400static int mag3110_suspend(struct device *dev)
401{
402 return mag3110_standby(iio_priv(i2c_get_clientdata(
403 to_i2c_client(dev))));
404}
405
406static int mag3110_resume(struct device *dev)
407{
408 struct mag3110_data *data = iio_priv(i2c_get_clientdata(
409 to_i2c_client(dev)));
410
411 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
412 data->ctrl_reg1);
413}
414
415static SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend, mag3110_resume);
416#define MAG3110_PM_OPS (&mag3110_pm_ops)
417#else
418#define MAG3110_PM_OPS NULL
419#endif
420
421static const struct i2c_device_id mag3110_id[] = {
422 { "mag3110", 0 },
423 { }
424};
425MODULE_DEVICE_TABLE(i2c, mag3110_id);
426
427static struct i2c_driver mag3110_driver = {
428 .driver = {
429 .name = "mag3110",
430 .pm = MAG3110_PM_OPS,
431 },
432 .probe = mag3110_probe,
433 .remove = mag3110_remove,
434 .id_table = mag3110_id,
435};
436module_i2c_driver(mag3110_driver);
437
438MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
439MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver");
440MODULE_LICENSE("GPL");
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