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12#include <linux/module.h>
13#include <linux/i2c.h>
14#include <linux/iio/iio.h>
15#include <linux/iio/sysfs.h>
16#include <linux/iio/trigger_consumer.h>
17#include <linux/iio/buffer.h>
18#include <linux/iio/triggered_buffer.h>
19#include <linux/delay.h>
20#include <linux/regulator/consumer.h>
21
22#define MAG3110_STATUS 0x00
23#define MAG3110_OUT_X 0x01
24#define MAG3110_OUT_Y 0x03
25#define MAG3110_OUT_Z 0x05
26#define MAG3110_WHO_AM_I 0x07
27#define MAG3110_SYSMOD 0x08
28#define MAG3110_OFF_X 0x09
29#define MAG3110_OFF_Y 0x0b
30#define MAG3110_OFF_Z 0x0d
31#define MAG3110_DIE_TEMP 0x0f
32#define MAG3110_CTRL_REG1 0x10
33#define MAG3110_CTRL_REG2 0x11
34
35#define MAG3110_STATUS_DRDY (BIT(2) | BIT(1) | BIT(0))
36
37#define MAG3110_CTRL_DR_MASK (BIT(7) | BIT(6) | BIT(5))
38#define MAG3110_CTRL_DR_SHIFT 5
39#define MAG3110_CTRL_DR_DEFAULT 0
40
41#define MAG3110_SYSMOD_MODE_MASK GENMASK(1, 0)
42
43#define MAG3110_CTRL_TM BIT(1)
44#define MAG3110_CTRL_AC BIT(0)
45
46#define MAG3110_CTRL_AUTO_MRST_EN BIT(7)
47#define MAG3110_CTRL_RAW BIT(5)
48
49#define MAG3110_DEVICE_ID 0xc4
50
51
52struct mag3110_data {
53 struct i2c_client *client;
54 struct mutex lock;
55 u8 ctrl_reg1;
56 int sleep_val;
57 struct regulator *vdd_reg;
58 struct regulator *vddio_reg;
59
60 struct {
61 __be16 channels[3];
62 u8 temperature;
63 s64 ts __aligned(8);
64 } scan;
65};
66
67static int mag3110_request(struct mag3110_data *data)
68{
69 int ret, tries = 150;
70
71 if ((data->ctrl_reg1 & MAG3110_CTRL_AC) == 0) {
72
73 ret = i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
74 data->ctrl_reg1 | MAG3110_CTRL_TM);
75 if (ret < 0)
76 return ret;
77 }
78
79 while (tries-- > 0) {
80 ret = i2c_smbus_read_byte_data(data->client, MAG3110_STATUS);
81 if (ret < 0)
82 return ret;
83
84 if ((ret & MAG3110_STATUS_DRDY) == MAG3110_STATUS_DRDY)
85 break;
86
87 if (data->sleep_val <= 20)
88 usleep_range(data->sleep_val * 250, data->sleep_val * 500);
89 else
90 msleep(20);
91 }
92
93 if (tries < 0) {
94 dev_err(&data->client->dev, "data not ready\n");
95 return -EIO;
96 }
97
98 return 0;
99}
100
101static int mag3110_read(struct mag3110_data *data, __be16 buf[3])
102{
103 int ret;
104
105 mutex_lock(&data->lock);
106 ret = mag3110_request(data);
107 if (ret < 0) {
108 mutex_unlock(&data->lock);
109 return ret;
110 }
111 ret = i2c_smbus_read_i2c_block_data(data->client,
112 MAG3110_OUT_X, 3 * sizeof(__be16), (u8 *) buf);
113 mutex_unlock(&data->lock);
114
115 return ret;
116}
117
118static ssize_t mag3110_show_int_plus_micros(char *buf,
119 const int (*vals)[2], int n)
120{
121 size_t len = 0;
122
123 while (n-- > 0)
124 len += scnprintf(buf + len, PAGE_SIZE - len,
125 "%d.%06d ", vals[n][0], vals[n][1]);
126
127
128 buf[len - 1] = '\n';
129
130 return len;
131}
132
133static int mag3110_get_int_plus_micros_index(const int (*vals)[2], int n,
134 int val, int val2)
135{
136 while (n-- > 0)
137 if (val == vals[n][0] && val2 == vals[n][1])
138 return n;
139
140 return -EINVAL;
141}
142
143static const int mag3110_samp_freq[8][2] = {
144 {80, 0}, {40, 0}, {20, 0}, {10, 0}, {5, 0}, {2, 500000},
145 {1, 250000}, {0, 625000}
146};
147
148static ssize_t mag3110_show_samp_freq_avail(struct device *dev,
149 struct device_attribute *attr, char *buf)
150{
151 return mag3110_show_int_plus_micros(buf, mag3110_samp_freq, 8);
152}
153
154static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(mag3110_show_samp_freq_avail);
155
156static int mag3110_get_samp_freq_index(struct mag3110_data *data,
157 int val, int val2)
158{
159 return mag3110_get_int_plus_micros_index(mag3110_samp_freq, 8, val,
160 val2);
161}
162
163static int mag3110_calculate_sleep(struct mag3110_data *data)
164{
165 int ret, i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
166
167 if (mag3110_samp_freq[i][0] > 0)
168 ret = 1000 / mag3110_samp_freq[i][0];
169 else
170 ret = 1000;
171
172 return ret == 0 ? 1 : ret;
173}
174
175static int mag3110_standby(struct mag3110_data *data)
176{
177 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
178 data->ctrl_reg1 & ~MAG3110_CTRL_AC);
179}
180
181static int mag3110_wait_standby(struct mag3110_data *data)
182{
183 int ret, tries = 30;
184
185
186
187
188
189
190 while (tries-- > 0) {
191 ret = i2c_smbus_read_byte_data(data->client, MAG3110_SYSMOD);
192 if (ret < 0) {
193 dev_err(&data->client->dev, "i2c error\n");
194 return ret;
195 }
196
197 if ((ret & MAG3110_SYSMOD_MODE_MASK) == 0)
198 break;
199
200 msleep_interruptible(500);
201 }
202
203 if (tries < 0) {
204 dev_err(&data->client->dev, "device not entering standby mode\n");
205 return -EIO;
206 }
207
208 return 0;
209}
210
211static int mag3110_active(struct mag3110_data *data)
212{
213 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
214 data->ctrl_reg1);
215}
216
217
218static int mag3110_is_active(struct mag3110_data *data)
219{
220 int reg;
221
222 reg = i2c_smbus_read_byte_data(data->client, MAG3110_CTRL_REG1);
223 if (reg < 0)
224 return reg;
225
226 return reg & MAG3110_CTRL_AC;
227}
228
229static int mag3110_change_config(struct mag3110_data *data, u8 reg, u8 val)
230{
231 int ret;
232 int is_active;
233
234 mutex_lock(&data->lock);
235
236 is_active = mag3110_is_active(data);
237 if (is_active < 0) {
238 ret = is_active;
239 goto fail;
240 }
241
242
243 if (is_active > 0) {
244 ret = mag3110_standby(data);
245 if (ret < 0)
246 goto fail;
247 }
248
249
250
251
252
253 ret = mag3110_wait_standby(data);
254 if (ret < 0)
255 goto fail;
256
257 ret = i2c_smbus_write_byte_data(data->client, reg, val);
258 if (ret < 0)
259 goto fail;
260
261 if (is_active > 0) {
262 ret = mag3110_active(data);
263 if (ret < 0)
264 goto fail;
265 }
266
267 ret = 0;
268fail:
269 mutex_unlock(&data->lock);
270
271 return ret;
272}
273
274static int mag3110_read_raw(struct iio_dev *indio_dev,
275 struct iio_chan_spec const *chan,
276 int *val, int *val2, long mask)
277{
278 struct mag3110_data *data = iio_priv(indio_dev);
279 __be16 buffer[3];
280 int i, ret;
281
282 switch (mask) {
283 case IIO_CHAN_INFO_RAW:
284 ret = iio_device_claim_direct_mode(indio_dev);
285 if (ret)
286 return ret;
287
288 switch (chan->type) {
289 case IIO_MAGN:
290 ret = mag3110_read(data, buffer);
291 if (ret < 0)
292 goto release;
293 *val = sign_extend32(
294 be16_to_cpu(buffer[chan->scan_index]), 15);
295 ret = IIO_VAL_INT;
296 break;
297 case IIO_TEMP:
298 mutex_lock(&data->lock);
299 ret = mag3110_request(data);
300 if (ret < 0) {
301 mutex_unlock(&data->lock);
302 goto release;
303 }
304 ret = i2c_smbus_read_byte_data(data->client,
305 MAG3110_DIE_TEMP);
306 mutex_unlock(&data->lock);
307 if (ret < 0)
308 goto release;
309 *val = sign_extend32(ret, 7);
310 ret = IIO_VAL_INT;
311 break;
312 default:
313 ret = -EINVAL;
314 }
315release:
316 iio_device_release_direct_mode(indio_dev);
317 return ret;
318
319 case IIO_CHAN_INFO_SCALE:
320 switch (chan->type) {
321 case IIO_MAGN:
322 *val = 0;
323 *val2 = 1000;
324 return IIO_VAL_INT_PLUS_MICRO;
325 case IIO_TEMP:
326 *val = 1000;
327 return IIO_VAL_INT;
328 default:
329 return -EINVAL;
330 }
331 case IIO_CHAN_INFO_SAMP_FREQ:
332 i = data->ctrl_reg1 >> MAG3110_CTRL_DR_SHIFT;
333 *val = mag3110_samp_freq[i][0];
334 *val2 = mag3110_samp_freq[i][1];
335 return IIO_VAL_INT_PLUS_MICRO;
336 case IIO_CHAN_INFO_CALIBBIAS:
337 ret = i2c_smbus_read_word_swapped(data->client,
338 MAG3110_OFF_X + 2 * chan->scan_index);
339 if (ret < 0)
340 return ret;
341 *val = sign_extend32(ret >> 1, 14);
342 return IIO_VAL_INT;
343 }
344 return -EINVAL;
345}
346
347static int mag3110_write_raw(struct iio_dev *indio_dev,
348 struct iio_chan_spec const *chan,
349 int val, int val2, long mask)
350{
351 struct mag3110_data *data = iio_priv(indio_dev);
352 int rate, ret;
353
354 ret = iio_device_claim_direct_mode(indio_dev);
355 if (ret)
356 return ret;
357
358 switch (mask) {
359 case IIO_CHAN_INFO_SAMP_FREQ:
360 rate = mag3110_get_samp_freq_index(data, val, val2);
361 if (rate < 0) {
362 ret = -EINVAL;
363 break;
364 }
365 data->ctrl_reg1 &= 0xff & ~MAG3110_CTRL_DR_MASK
366 & ~MAG3110_CTRL_AC;
367 data->ctrl_reg1 |= rate << MAG3110_CTRL_DR_SHIFT;
368 data->sleep_val = mag3110_calculate_sleep(data);
369 if (data->sleep_val < 40)
370 data->ctrl_reg1 |= MAG3110_CTRL_AC;
371
372 ret = mag3110_change_config(data, MAG3110_CTRL_REG1,
373 data->ctrl_reg1);
374 break;
375 case IIO_CHAN_INFO_CALIBBIAS:
376 if (val < -10000 || val > 10000) {
377 ret = -EINVAL;
378 break;
379 }
380 ret = i2c_smbus_write_word_swapped(data->client,
381 MAG3110_OFF_X + 2 * chan->scan_index, val << 1);
382 break;
383 default:
384 ret = -EINVAL;
385 break;
386 }
387 iio_device_release_direct_mode(indio_dev);
388 return ret;
389}
390
391static irqreturn_t mag3110_trigger_handler(int irq, void *p)
392{
393 struct iio_poll_func *pf = p;
394 struct iio_dev *indio_dev = pf->indio_dev;
395 struct mag3110_data *data = iio_priv(indio_dev);
396 int ret;
397
398 ret = mag3110_read(data, data->scan.channels);
399 if (ret < 0)
400 goto done;
401
402 if (test_bit(3, indio_dev->active_scan_mask)) {
403 ret = i2c_smbus_read_byte_data(data->client,
404 MAG3110_DIE_TEMP);
405 if (ret < 0)
406 goto done;
407 data->scan.temperature = ret;
408 }
409
410 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
411 iio_get_time_ns(indio_dev));
412
413done:
414 iio_trigger_notify_done(indio_dev->trig);
415 return IRQ_HANDLED;
416}
417
418#define MAG3110_CHANNEL(axis, idx) { \
419 .type = IIO_MAGN, \
420 .modified = 1, \
421 .channel2 = IIO_MOD_##axis, \
422 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
423 BIT(IIO_CHAN_INFO_CALIBBIAS), \
424 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
425 BIT(IIO_CHAN_INFO_SCALE), \
426 .scan_index = idx, \
427 .scan_type = { \
428 .sign = 's', \
429 .realbits = 16, \
430 .storagebits = 16, \
431 .endianness = IIO_BE, \
432 }, \
433}
434
435static const struct iio_chan_spec mag3110_channels[] = {
436 MAG3110_CHANNEL(X, 0),
437 MAG3110_CHANNEL(Y, 1),
438 MAG3110_CHANNEL(Z, 2),
439 {
440 .type = IIO_TEMP,
441 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
442 BIT(IIO_CHAN_INFO_SCALE),
443 .scan_index = 3,
444 .scan_type = {
445 .sign = 's',
446 .realbits = 8,
447 .storagebits = 8,
448 },
449 },
450 IIO_CHAN_SOFT_TIMESTAMP(4),
451};
452
453static struct attribute *mag3110_attributes[] = {
454 &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
455 NULL
456};
457
458static const struct attribute_group mag3110_group = {
459 .attrs = mag3110_attributes,
460};
461
462static const struct iio_info mag3110_info = {
463 .attrs = &mag3110_group,
464 .read_raw = &mag3110_read_raw,
465 .write_raw = &mag3110_write_raw,
466};
467
468static const unsigned long mag3110_scan_masks[] = {0x7, 0xf, 0};
469
470static int mag3110_probe(struct i2c_client *client,
471 const struct i2c_device_id *id)
472{
473 struct mag3110_data *data;
474 struct iio_dev *indio_dev;
475 int ret;
476
477 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
478 if (!indio_dev)
479 return -ENOMEM;
480
481 data = iio_priv(indio_dev);
482
483 data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
484 if (IS_ERR(data->vdd_reg))
485 return dev_err_probe(&client->dev, PTR_ERR(data->vdd_reg),
486 "failed to get VDD regulator!\n");
487
488 data->vddio_reg = devm_regulator_get(&client->dev, "vddio");
489 if (IS_ERR(data->vddio_reg))
490 return dev_err_probe(&client->dev, PTR_ERR(data->vddio_reg),
491 "failed to get VDDIO regulator!\n");
492
493 ret = regulator_enable(data->vdd_reg);
494 if (ret) {
495 dev_err(&client->dev, "failed to enable VDD regulator!\n");
496 return ret;
497 }
498
499 ret = regulator_enable(data->vddio_reg);
500 if (ret) {
501 dev_err(&client->dev, "failed to enable VDDIO regulator!\n");
502 goto disable_regulator_vdd;
503 }
504
505 ret = i2c_smbus_read_byte_data(client, MAG3110_WHO_AM_I);
506 if (ret < 0)
507 goto disable_regulators;
508 if (ret != MAG3110_DEVICE_ID) {
509 ret = -ENODEV;
510 goto disable_regulators;
511 }
512
513 data->client = client;
514 mutex_init(&data->lock);
515
516 i2c_set_clientdata(client, indio_dev);
517 indio_dev->info = &mag3110_info;
518 indio_dev->name = id->name;
519 indio_dev->modes = INDIO_DIRECT_MODE;
520 indio_dev->channels = mag3110_channels;
521 indio_dev->num_channels = ARRAY_SIZE(mag3110_channels);
522 indio_dev->available_scan_masks = mag3110_scan_masks;
523
524 data->ctrl_reg1 = MAG3110_CTRL_DR_DEFAULT << MAG3110_CTRL_DR_SHIFT;
525 data->sleep_val = mag3110_calculate_sleep(data);
526 if (data->sleep_val < 40)
527 data->ctrl_reg1 |= MAG3110_CTRL_AC;
528
529 ret = mag3110_change_config(data, MAG3110_CTRL_REG1, data->ctrl_reg1);
530 if (ret < 0)
531 goto disable_regulators;
532
533 ret = i2c_smbus_write_byte_data(client, MAG3110_CTRL_REG2,
534 MAG3110_CTRL_AUTO_MRST_EN);
535 if (ret < 0)
536 goto standby_on_error;
537
538 ret = iio_triggered_buffer_setup(indio_dev, NULL,
539 mag3110_trigger_handler, NULL);
540 if (ret < 0)
541 goto standby_on_error;
542
543 ret = iio_device_register(indio_dev);
544 if (ret < 0)
545 goto buffer_cleanup;
546 return 0;
547
548buffer_cleanup:
549 iio_triggered_buffer_cleanup(indio_dev);
550standby_on_error:
551 mag3110_standby(iio_priv(indio_dev));
552disable_regulators:
553 regulator_disable(data->vddio_reg);
554disable_regulator_vdd:
555 regulator_disable(data->vdd_reg);
556
557 return ret;
558}
559
560static int mag3110_remove(struct i2c_client *client)
561{
562 struct iio_dev *indio_dev = i2c_get_clientdata(client);
563 struct mag3110_data *data = iio_priv(indio_dev);
564
565 iio_device_unregister(indio_dev);
566 iio_triggered_buffer_cleanup(indio_dev);
567 mag3110_standby(iio_priv(indio_dev));
568 regulator_disable(data->vddio_reg);
569 regulator_disable(data->vdd_reg);
570
571 return 0;
572}
573
574#ifdef CONFIG_PM_SLEEP
575static int mag3110_suspend(struct device *dev)
576{
577 struct mag3110_data *data = iio_priv(i2c_get_clientdata(
578 to_i2c_client(dev)));
579 int ret;
580
581 ret = mag3110_standby(iio_priv(i2c_get_clientdata(
582 to_i2c_client(dev))));
583 if (ret)
584 return ret;
585
586 ret = regulator_disable(data->vddio_reg);
587 if (ret) {
588 dev_err(dev, "failed to disable VDDIO regulator\n");
589 return ret;
590 }
591
592 ret = regulator_disable(data->vdd_reg);
593 if (ret) {
594 dev_err(dev, "failed to disable VDD regulator\n");
595 return ret;
596 }
597
598 return 0;
599}
600
601static int mag3110_resume(struct device *dev)
602{
603 struct mag3110_data *data = iio_priv(i2c_get_clientdata(
604 to_i2c_client(dev)));
605 int ret;
606
607 ret = regulator_enable(data->vdd_reg);
608 if (ret) {
609 dev_err(dev, "failed to enable VDD regulator\n");
610 return ret;
611 }
612
613 ret = regulator_enable(data->vddio_reg);
614 if (ret) {
615 dev_err(dev, "failed to enable VDDIO regulator\n");
616 regulator_disable(data->vdd_reg);
617 return ret;
618 }
619
620 return i2c_smbus_write_byte_data(data->client, MAG3110_CTRL_REG1,
621 data->ctrl_reg1);
622}
623
624static SIMPLE_DEV_PM_OPS(mag3110_pm_ops, mag3110_suspend, mag3110_resume);
625#define MAG3110_PM_OPS (&mag3110_pm_ops)
626#else
627#define MAG3110_PM_OPS NULL
628#endif
629
630static const struct i2c_device_id mag3110_id[] = {
631 { "mag3110", 0 },
632 { }
633};
634MODULE_DEVICE_TABLE(i2c, mag3110_id);
635
636static const struct of_device_id mag3110_of_match[] = {
637 { .compatible = "fsl,mag3110" },
638 { }
639};
640MODULE_DEVICE_TABLE(of, mag3110_of_match);
641
642static struct i2c_driver mag3110_driver = {
643 .driver = {
644 .name = "mag3110",
645 .of_match_table = mag3110_of_match,
646 .pm = MAG3110_PM_OPS,
647 },
648 .probe = mag3110_probe,
649 .remove = mag3110_remove,
650 .id_table = mag3110_id,
651};
652module_i2c_driver(mag3110_driver);
653
654MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
655MODULE_DESCRIPTION("Freescale MAG3110 magnetometer driver");
656MODULE_LICENSE("GPL");
657
