Linux kernel mirror (for testing)
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linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * mag3110.c - Support for Freescale MAG3110 magnetometer sensor
4 *
5 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
6 *
7 * (7-bit I2C slave address 0x0e)
8 *
9 * TODO: irq, user offset, oversampling, continuous mode
10 */
11
12#include <linux/cleanup.h>
13#include <linux/module.h>
14#include <linux/i2c.h>
15#include <linux/iio/iio.h>
16#include <linux/iio/sysfs.h>
17#include <linux/iio/trigger_consumer.h>
18#include <linux/iio/buffer.h>
19#include <linux/iio/triggered_buffer.h>
20#include <linux/delay.h>
21#include <linux/regulator/consumer.h>
22
23#define MAG3110_STATUS 0x00
24#define MAG3110_OUT_X 0x01 /* MSB first */
25#define MAG3110_OUT_Y 0x03
26#define MAG3110_OUT_Z 0x05
27#define MAG3110_WHO_AM_I 0x07
28#define MAG3110_SYSMOD 0x08
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_SYSMOD_MODE_MASK GENMASK(1, 0)
43
44#define MAG3110_CTRL_TM BIT(1) /* trigger single measurement */
45#define MAG3110_CTRL_AC BIT(0) /* continuous measurements */
46
47#define MAG3110_CTRL_AUTO_MRST_EN BIT(7) /* magnetic auto-reset */
48#define MAG3110_CTRL_RAW BIT(5) /* measurements not user-offset corrected */
49
50#define MAG3110_DEVICE_ID 0xc4
51
52/* Each client has this additional data */
53struct mag3110_data {
54 struct i2c_client *client;
55 struct mutex lock;
56 u8 ctrl_reg1;
57 int sleep_val;
58 struct regulator *vdd_reg;
59 struct regulator *vddio_reg;
60 /* Ensure natural alignment of timestamp */
61 struct {
62 __be16 channels[3];
63 u8 temperature;
64 aligned_s64 ts;
65 } scan;
66};
67
68static int mag3110_request(struct mag3110_data *data)
69{
70 int ret, tries = 150;
71
72 if ((data->ctrl_reg1 & MAG3110_CTRL_AC) == 0) {
73 /* trigger measurement */
74 ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
75 data->ctrl_reg1 | MAG3110_CTRL_TM);
76 if (ret < 0)
77 return ret;
78 }
79
80 while (tries-- > 0) {
81 ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);
82 if (ret < 0)
83 return ret;
84 /* wait for data ready */
85 if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)
86 break;
87
88 if (data->sleep_val <= 20)
89 usleep_range(data->sleep_val * 250, data->sleep_val * 500);
90 else
91 msleep(20);
92 }
93
94 if (tries < 0) {
95 dev_err(&data->client->dev, "data not ready\n");
96 return -EIO;
97 }
98
99 return 0;
100}
101
102static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
103{
104 int ret;
105
106 guard(mutex)(&data->lock);
107 ret = mag3110_request(data);
108 if (ret < 0)
109 return ret;
110 return i2c_smbus_read_i2c_block_data(data->client, MAG3110_OUT_X,
111 3 * sizeof(__be16), (u8 *) buf);
112}
113
114static ssize_t mag3110_show_int_plus_micros(char *buf,
115 const int (*vals)[2], int n)
116{
117 size_t len = 0;
118
119 while (n-- > 0)
120 len += scnprintf(buf + len, PAGE_SIZE - len,
121 "%d.%06d ", vals[n][0], vals[n][1]);
122
123 /* replace trailing space by newline */
124 buf[len - 1] = '\n';
125
126 return len;
127}
128
129static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,
130 int val, int val2)
131{
132 while (n-- > 0)
133 if (val == vals[n][0] && val2 == vals[n][1])
134 return n;
135
136 return -EINVAL;
137}
138
139static const int mag3110_samp_freq[8][2] = {
140 {80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},
141 {1, 250000}, {0, 625000}
142};
143
144static ssize_t mag3110_show_samp_freq_avail(struct device *dev,
145 struct device_attribute *attr, char *buf)
146{
147 return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8);
148}
149
150static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail);
151
152static int mag3110_get_samp_freq_index(struct mag3110_data *data,
153 int val, int val2)
154{
155 return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val,
156 val2);
157}
158
159static int mag3110_calculate_sleep(struct mag3110_data *data)
160{
161 int ret, i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
162
163 if (mag3110_samp_freq[i][0] > 0)
164 ret = 1000 / mag3110_samp_freq[i][0];
165 else
166 ret = 1000;
167
168 return ret == 0 ? 1 : ret;
169}
170
171static int mag3110_standby(struct mag3110_data *data)
172{
173 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
174 data->ctrl_reg1 & ~MAG3110_CTRL_AC);
175}
176
177static int mag3110_wait_standby(struct mag3110_data *data)
178{
179 int ret, tries = 30;
180
181 /*
182 * Takes up to 1/ODR to come out of active mode into stby
183 * Longest expected period is 12.5seconds.
184 * We'll sleep for 500ms between checks
185 */
186 while (tries-- > 0) {
187 ret = i2c_smbus_read_byte_data(data->client, MAG3110_SYSMOD);
188 if (ret < 0) {
189 dev_err(&data->client->dev, "i2c error\n");
190 return ret;
191 }
192 /* wait for standby */
193 if ((ret & MAG3110_SYSMOD_MODE_MASK) == 0)
194 break;
195
196 msleep_interruptible(500);
197 }
198
199 if (tries < 0) {
200 dev_err(&data->client->dev, "device not entering standby mode\n");
201 return -EIO;
202 }
203
204 return 0;
205}
206
207static int mag3110_active(struct mag3110_data *data)
208{
209 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
210 data->ctrl_reg1);
211}
212
213/* returns >0 if active, 0 if in standby and <0 on error */
214static int mag3110_is_active(struct mag3110_data *data)
215{
216 int reg;
217
218 reg = i2c_smbus_read_byte_data(data->client, MAG3110_CTRL_REG1);
219 if (reg < 0)
220 return reg;
221
222 return reg & MAG3110_CTRL_AC;
223}
224
225static int mag3110_change_config(struct mag3110_data *data, u8 reg, u8 val)
226{
227 int ret;
228 int is_active;
229
230 guard(mutex)(&data->lock);
231
232 is_active = mag3110_is_active(data);
233 if (is_active < 0)
234 return is_active;
235
236 /* config can only be changed when in standby */
237 if (is_active > 0) {
238 ret = mag3110_standby(data);
239 if (ret < 0)
240 return ret;
241 }
242
243 /*
244 * After coming out of active we must wait for the part
245 * to transition to STBY. This can take up to 1 /ODR to occur
246 */
247 ret = mag3110_wait_standby(data);
248 if (ret < 0)
249 return ret;
250
251 ret = i2c_smbus_write_byte_data(data->client, reg, val);
252 if (ret < 0)
253 return ret;
254
255 if (is_active > 0) {
256 ret = mag3110_active(data);
257 if (ret < 0)
258 return ret;
259 }
260
261 return 0;
262}
263
264static int __mag3110_read_info_raw(struct mag3110_data *data,
265 struct iio_chan_spec const *chan,
266 int *val)
267{
268 __be16 buffer[3];
269 int ret;
270
271 switch (chan->type) {
272 case IIO_MAGN: /* in 0.1 uT / LSB */
273 ret = mag3110_read(data, buffer);
274 if (ret < 0)
275 return ret;
276 *val = sign_extend32(be16_to_cpu(buffer[chan->scan_index]),
277 chan->scan_type.realbits - 1);
278 return IIO_VAL_INT;
279
280 case IIO_TEMP: { /* in 1 C / LSB */
281 guard(mutex)(&data->lock);
282 ret = mag3110_request(data);
283 if (ret < 0)
284 return ret;
285 ret = i2c_smbus_read_byte_data(data->client,
286 MAG3110_DIE_TEMP);
287 if (ret < 0)
288 return ret;
289 *val = sign_extend32(ret, chan->scan_type.realbits - 1);
290 return IIO_VAL_INT;
291 }
292 default:
293 return -EINVAL;
294 }
295}
296
297static int mag3110_read_raw(struct iio_dev *indio_dev,
298 struct iio_chan_spec const *chan,
299 int *val, int *val2, long mask)
300{
301 struct mag3110_data *data = iio_priv(indio_dev);
302 int i, ret;
303
304 switch (mask) {
305 case IIO_CHAN_INFO_RAW:
306 if (!iio_device_claim_direct(indio_dev))
307 return -EBUSY;
308 ret = __mag3110_read_info_raw(data, chan, val);
309 iio_device_release_direct(indio_dev);
310 return ret;
311
312 case IIO_CHAN_INFO_SCALE:
313 switch (chan->type) {
314 case IIO_MAGN:
315 *val = 0;
316 *val2 = 1000;
317 return IIO_VAL_INT_PLUS_MICRO;
318 case IIO_TEMP:
319 *val = 1000;
320 return IIO_VAL_INT;
321 default:
322 return -EINVAL;
323 }
324 case IIO_CHAN_INFO_SAMP_FREQ:
325 i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
326 *val = mag3110_samp_freq[i][0];
327 *val2 = mag3110_samp_freq[i][1];
328 return IIO_VAL_INT_PLUS_MICRO;
329 case IIO_CHAN_INFO_CALIBBIAS:
330 ret = i2c_smbus_read_word_swapped(data->client,
331 MAG3110_OFF_X + 2 * chan->scan_index);
332 if (ret < 0)
333 return ret;
334 *val = sign_extend32(ret >> 1, 14);
335 return IIO_VAL_INT;
336 }
337 return -EINVAL;
338}
339
340static int __mag3110_write_raw(struct mag3110_data *data,
341 struct iio_chan_spec const *chan,
342 int val, int val2, long mask)
343{
344 int rate;
345
346 switch (mask) {
347 case IIO_CHAN_INFO_SAMP_FREQ:
348 rate = mag3110_get_samp_freq_index(data, val, val2);
349 if (rate < 0)
350 return -EINVAL;
351
352 data->ctrl_reg1 &= 0xff & ~MAG3110_CTRL_DR_MASK
353 & ~MAG3110_CTRL_AC;
354 data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;
355 data->sleep_val = mag3110_calculate_sleep(data);
356 if (data->sleep_val < 40)
357 data->ctrl_reg1 |= MAG3110_CTRL_AC;
358
359 return mag3110_change_config(data, MAG3110_CTRL_REG1,
360 data->ctrl_reg1);
361
362 case IIO_CHAN_INFO_CALIBBIAS:
363 if (val < -10000 || val > 10000)
364 return -EINVAL;
365
366 return i2c_smbus_write_word_swapped(data->client,
367 MAG3110_OFF_X + 2 * chan->scan_index, val << 1);
368 default:
369 return -EINVAL;
370 }
371}
372
373static int mag3110_write_raw(struct iio_dev *indio_dev,
374 struct iio_chan_spec const *chan,
375 int val, int val2, long mask)
376{
377 struct mag3110_data *data = iio_priv(indio_dev);
378 int ret;
379
380 if (!iio_device_claim_direct(indio_dev))
381 return -EBUSY;
382 ret = __mag3110_write_raw(data, chan, val, val2, mask);
383 iio_device_release_direct(indio_dev);
384
385 return ret;
386}
387
388static irqreturn_t mag3110_trigger_handler(int irq, void *p)
389{
390 struct iio_poll_func *pf = p;
391 struct iio_dev *indio_dev = pf->indio_dev;
392 struct mag3110_data *data = iio_priv(indio_dev);
393 int ret;
394
395 ret = mag3110_read(data, data->scan.channels);
396 if (ret < 0)
397 goto done;
398
399 if (test_bit(3, indio_dev->active_scan_mask)) {
400 ret = i2c_smbus_read_byte_data(data->client,
401 MAG3110_DIE_TEMP);
402 if (ret < 0)
403 goto done;
404 data->scan.temperature = ret;
405 }
406
407 iio_push_to_buffers_with_ts(indio_dev, &data->scan, sizeof(data->scan),
408 iio_get_time_ns(indio_dev));
409
410done:
411 iio_trigger_notify_done(indio_dev->trig);
412 return IRQ_HANDLED;
413}
414
415#define MAG3110_CHANNEL(axis, idx) { \
416 .type = IIO_MAGN, \
417 .modified = 1, \
418 .channel2 = IIO_MOD_##axis, \
419 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
420 BIT(IIO_CHAN_INFO_CALIBBIAS), \
421 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
422 BIT(IIO_CHAN_INFO_SCALE), \
423 .scan_index = idx, \
424 .scan_type = { \
425 .sign = 's', \
426 .realbits = 16, \
427 .storagebits = 16, \
428 .endianness = IIO_BE, \
429 }, \
430}
431
432static const struct iio_chan_spec mag3110_channels[] = {
433 MAG3110_CHANNEL(X, 0),
434 MAG3110_CHANNEL(Y, 1),
435 MAG3110_CHANNEL(Z, 2),
436 {
437 .type = IIO_TEMP,
438 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
439 BIT(IIO_CHAN_INFO_SCALE),
440 .scan_index = 3,
441 .scan_type = {
442 .sign = 's',
443 .realbits = 8,
444 .storagebits = 8,
445 },
446 },
447 IIO_CHAN_SOFT_TIMESTAMP(4),
448};
449
450static struct attribute *mag3110_attributes[] = {
451 &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
452 NULL
453};
454
455static const struct attribute_group mag3110_group = {
456 .attrs = mag3110_attributes,
457};
458
459static const struct iio_info mag3110_info = {
460 .attrs = &mag3110_group,
461 .read_raw = &mag3110_read_raw,
462 .write_raw = &mag3110_write_raw,
463};
464
465static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0};
466
467static int mag3110_probe(struct i2c_client *client)
468{
469 const struct i2c_device_id *id = i2c_client_get_device_id(client);
470 struct mag3110_data *data;
471 struct iio_dev *indio_dev;
472 int ret;
473
474 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
475 if (!indio_dev)
476 return -ENOMEM;
477
478 data = iio_priv(indio_dev);
479
480 data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
481 if (IS_ERR(data->vdd_reg))
482 return dev_err_probe(&client->dev, PTR_ERR(data->vdd_reg),
483 "failed to get VDD regulator!\n");
484
485 data->vddio_reg = devm_regulator_get(&client->dev, "vddio");
486 if (IS_ERR(data->vddio_reg))
487 return dev_err_probe(&client->dev, PTR_ERR(data->vddio_reg),
488 "failed to get VDDIO regulator!\n");
489
490 ret = regulator_enable(data->vdd_reg);
491 if (ret) {
492 dev_err(&client->dev, "failed to enable VDD regulator!\n");
493 return ret;
494 }
495
496 ret = regulator_enable(data->vddio_reg);
497 if (ret) {
498 dev_err(&client->dev, "failed to enable VDDIO regulator!\n");
499 goto disable_regulator_vdd;
500 }
501
502 ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I);
503 if (ret < 0)
504 goto disable_regulators;
505 if (ret != MAG3110_DEVICE_ID) {
506 ret = -ENODEV;
507 goto disable_regulators;
508 }
509
510 data->client = client;
511 mutex_init(&data->lock);
512
513 i2c_set_clientdata(client, indio_dev);
514 indio_dev->info = &mag3110_info;
515 indio_dev->name = id->name;
516 indio_dev->modes = INDIO_DIRECT_MODE;
517 indio_dev->channels = mag3110_channels;
518 indio_dev->num_channels = ARRAY_SIZE(mag3110_channels);
519 indio_dev->available_scan_masks = mag3110_scan_masks;
520
521 data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT << MAG3110_CTRL_DR_SHIFT;
522 data->sleep_val = mag3110_calculate_sleep(data);
523 if (data->sleep_val < 40)
524 data->ctrl_reg1 |= MAG3110_CTRL_AC;
525
526 ret = mag3110_change_config(data, MAG3110_CTRL_REG1, data->ctrl_reg1);
527 if (ret < 0)
528 goto disable_regulators;
529
530 ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2,
531 MAG3110_CTRL_AUTO_MRST_EN);
532 if (ret < 0)
533 goto standby_on_error;
534
535 ret = iio_triggered_buffer_setup(indio_dev, NULL,
536 mag3110_trigger_handler, NULL);
537 if (ret < 0)
538 goto standby_on_error;
539
540 ret = iio_device_register(indio_dev);
541 if (ret < 0)
542 goto buffer_cleanup;
543 return 0;
544
545buffer_cleanup:
546 iio_triggered_buffer_cleanup(indio_dev);
547standby_on_error:
548 mag3110_standby(iio_priv(indio_dev));
549disable_regulators:
550 regulator_disable(data->vddio_reg);
551disable_regulator_vdd:
552 regulator_disable(data->vdd_reg);
553
554 return ret;
555}
556
557static void mag3110_remove(struct i2c_client *client)
558{
559 struct iio_dev *indio_dev = i2c_get_clientdata(client);
560 struct mag3110_data *data = iio_priv(indio_dev);
561
562 iio_device_unregister(indio_dev);
563 iio_triggered_buffer_cleanup(indio_dev);
564 mag3110_standby(iio_priv(indio_dev));
565 regulator_disable(data->vddio_reg);
566 regulator_disable(data->vdd_reg);
567}
568
569static int mag3110_suspend(struct device *dev)
570{
571 struct mag3110_data *data = iio_priv(i2c_get_clientdata(
572 to_i2c_client(dev)));
573 int ret;
574
575 ret = mag3110_standby(iio_priv(i2c_get_clientdata(
576 to_i2c_client(dev))));
577 if (ret)
578 return ret;
579
580 ret = regulator_disable(data->vddio_reg);
581 if (ret) {
582 dev_err(dev, "failed to disable VDDIO regulator\n");
583 return ret;
584 }
585
586 ret = regulator_disable(data->vdd_reg);
587 if (ret) {
588 dev_err(dev, "failed to disable VDD regulator\n");
589 return ret;
590 }
591
592 return 0;
593}
594
595static int mag3110_resume(struct device *dev)
596{
597 struct mag3110_data *data = iio_priv(i2c_get_clientdata(
598 to_i2c_client(dev)));
599 int ret;
600
601 ret = regulator_enable(data->vdd_reg);
602 if (ret) {
603 dev_err(dev, "failed to enable VDD regulator\n");
604 return ret;
605 }
606
607 ret = regulator_enable(data->vddio_reg);
608 if (ret) {
609 dev_err(dev, "failed to enable VDDIO regulator\n");
610 regulator_disable(data->vdd_reg);
611 return ret;
612 }
613
614 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
615 data->ctrl_reg1);
616}
617
618static DEFINE_SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend,
619 mag3110_resume);
620
621static const struct i2c_device_id mag3110_id[] = {
622 { "mag3110" },
623 { }
624};
625MODULE_DEVICE_TABLE(i2c, mag3110_id);
626
627static const struct of_device_id mag3110_of_match[] = {
628 { .compatible = "fsl,mag3110" },
629 { }
630};
631MODULE_DEVICE_TABLE(of, mag3110_of_match);
632
633static struct i2c_driver mag3110_driver = {
634 .driver = {
635 .name = "mag3110",
636 .of_match_table = mag3110_of_match,
637 .pm = pm_sleep_ptr(&mag3110_pm_ops),
638 },
639 .probe = mag3110_probe,
640 .remove = mag3110_remove,
641 .id_table = mag3110_id,
642};
643module_i2c_driver(mag3110_driver);
644
645MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
646MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver");
647MODULE_LICENSE("GPL");