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10#include <linux/i2c.h>
11#include <linux/interrupt.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/delay.h>
15#include <linux/iio/buffer.h>
16#include <linux/iio/iio.h>
17#include <linux/iio/sysfs.h>
18#include <linux/iio/trigger.h>
19#include <linux/iio/triggered_buffer.h>
20#include <linux/iio/trigger_consumer.h>
21
22#define STK8312_REG_XOUT 0x00
23#define STK8312_REG_YOUT 0x01
24#define STK8312_REG_ZOUT 0x02
25#define STK8312_REG_INTSU 0x06
26#define STK8312_REG_MODE 0x07
27#define STK8312_REG_SR 0x08
28#define STK8312_REG_STH 0x13
29#define STK8312_REG_RESET 0x20
30#define STK8312_REG_AFECTRL 0x24
31#define STK8312_REG_OTPADDR 0x3D
32#define STK8312_REG_OTPDATA 0x3E
33#define STK8312_REG_OTPCTRL 0x3F
34
35#define STK8312_MODE_ACTIVE BIT(0)
36#define STK8312_MODE_STANDBY 0x00
37#define STK8312_MODE_INT_AH_PP 0xC0
38#define STK8312_DREADY_BIT BIT(4)
39#define STK8312_RNG_6G 1
40#define STK8312_RNG_SHIFT 6
41#define STK8312_RNG_MASK GENMASK(7, 6)
42#define STK8312_SR_MASK GENMASK(2, 0)
43#define STK8312_SR_400HZ_IDX 0
44#define STK8312_ALL_CHANNEL_MASK GENMASK(2, 0)
45#define STK8312_ALL_CHANNEL_SIZE 3
46
47#define STK8312_DRIVER_NAME "stk8312"
48#define STK8312_IRQ_NAME "stk8312_event"
49
50
51
52
53
54
55
56
57
58
59#define STK8312_SCALE_AVAIL "0.4616 1.2311"
60
61static const int stk8312_scale_table[][2] = {
62 {0, 461600}, {1, 231100}
63};
64
65static const struct {
66 int val;
67 int val2;
68} stk8312_samp_freq_table[] = {
69 {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0},
70 {12, 500000}, {6, 250000}, {3, 125000}
71};
72
73#define STK8312_ACCEL_CHANNEL(index, reg, axis) { \
74 .type = IIO_ACCEL, \
75 .address = reg, \
76 .modified = 1, \
77 .channel2 = IIO_MOD_##axis, \
78 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
79 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
80 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
81 .scan_index = index, \
82 .scan_type = { \
83 .sign = 's', \
84 .realbits = 8, \
85 .storagebits = 8, \
86 .endianness = IIO_CPU, \
87 }, \
88}
89
90static const struct iio_chan_spec stk8312_channels[] = {
91 STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X),
92 STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y),
93 STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z),
94 IIO_CHAN_SOFT_TIMESTAMP(3),
95};
96
97struct stk8312_data {
98 struct i2c_client *client;
99 struct mutex lock;
100 u8 range;
101 u8 sample_rate_idx;
102 u8 mode;
103 struct iio_trigger *dready_trig;
104 bool dready_trigger_on;
105
106 struct {
107 s8 chans[3];
108 s64 timestamp __aligned(8);
109 } scan;
110};
111
112static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
113
114static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");
115
116static struct attribute *stk8312_attributes[] = {
117 &iio_const_attr_in_accel_scale_available.dev_attr.attr,
118 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
119 NULL,
120};
121
122static const struct attribute_group stk8312_attribute_group = {
123 .attrs = stk8312_attributes
124};
125
126static int stk8312_otp_init(struct stk8312_data *data)
127{
128 int ret;
129 int count = 10;
130 struct i2c_client *client = data->client;
131
132 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
133 if (ret < 0)
134 goto exit_err;
135 ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
136 if (ret < 0)
137 goto exit_err;
138
139 do {
140 usleep_range(1000, 5000);
141 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
142 if (ret < 0)
143 goto exit_err;
144 count--;
145 } while (!(ret & BIT(7)) && count > 0);
146
147 if (count == 0) {
148 ret = -ETIMEDOUT;
149 goto exit_err;
150 }
151
152 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
153 if (ret == 0)
154 ret = -EINVAL;
155 if (ret < 0)
156 goto exit_err;
157
158 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_AFECTRL, ret);
159 if (ret < 0)
160 goto exit_err;
161 msleep(150);
162
163 return 0;
164
165exit_err:
166 dev_err(&client->dev, "failed to initialize sensor\n");
167 return ret;
168}
169
170static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
171{
172 int ret;
173 struct i2c_client *client = data->client;
174
175 if (mode == data->mode)
176 return 0;
177
178 ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode);
179 if (ret < 0) {
180 dev_err(&client->dev, "failed to change sensor mode\n");
181 return ret;
182 }
183
184 data->mode = mode;
185 if (mode & STK8312_MODE_ACTIVE) {
186
187 usleep_range(1000, 5000);
188 ret = stk8312_otp_init(data);
189 }
190
191 return ret;
192}
193
194static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask)
195{
196 int ret;
197 u8 mode;
198 struct i2c_client *client = data->client;
199
200 mode = data->mode;
201
202 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
203 if (ret < 0)
204 return ret;
205
206 ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask);
207 if (ret < 0) {
208 dev_err(&client->dev, "failed to set interrupts\n");
209 stk8312_set_mode(data, mode);
210 return ret;
211 }
212
213 return stk8312_set_mode(data, mode);
214}
215
216static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig,
217 bool state)
218{
219 struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
220 struct stk8312_data *data = iio_priv(indio_dev);
221 int ret;
222
223 if (state)
224 ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT);
225 else
226 ret = stk8312_set_interrupts(data, 0x00);
227
228 if (ret < 0) {
229 dev_err(&data->client->dev, "failed to set trigger state\n");
230 return ret;
231 }
232
233 data->dready_trigger_on = state;
234
235 return 0;
236}
237
238static const struct iio_trigger_ops stk8312_trigger_ops = {
239 .set_trigger_state = stk8312_data_rdy_trigger_set_state,
240};
241
242static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate)
243{
244 int ret;
245 u8 masked_reg;
246 u8 mode;
247 struct i2c_client *client = data->client;
248
249 if (rate == data->sample_rate_idx)
250 return 0;
251
252 mode = data->mode;
253
254 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
255 if (ret < 0)
256 return ret;
257
258 ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR);
259 if (ret < 0)
260 goto err_activate;
261
262 masked_reg = (ret & (~STK8312_SR_MASK)) | rate;
263
264 ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg);
265 if (ret < 0)
266 goto err_activate;
267
268 data->sample_rate_idx = rate;
269
270 return stk8312_set_mode(data, mode);
271
272err_activate:
273 dev_err(&client->dev, "failed to set sampling rate\n");
274 stk8312_set_mode(data, mode);
275
276 return ret;
277}
278
279static int stk8312_set_range(struct stk8312_data *data, u8 range)
280{
281 int ret;
282 u8 masked_reg;
283 u8 mode;
284 struct i2c_client *client = data->client;
285
286 if (range != 1 && range != 2)
287 return -EINVAL;
288 else if (range == data->range)
289 return 0;
290
291 mode = data->mode;
292
293 ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
294 if (ret < 0)
295 return ret;
296
297 ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
298 if (ret < 0)
299 goto err_activate;
300
301 masked_reg = ret & (~STK8312_RNG_MASK);
302 masked_reg |= range << STK8312_RNG_SHIFT;
303
304 ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
305 if (ret < 0)
306 goto err_activate;
307
308 data->range = range;
309
310 return stk8312_set_mode(data, mode);
311
312err_activate:
313 dev_err(&client->dev, "failed to change sensor range\n");
314 stk8312_set_mode(data, mode);
315
316 return ret;
317}
318
319static int stk8312_read_accel(struct stk8312_data *data, u8 address)
320{
321 int ret;
322 struct i2c_client *client = data->client;
323
324 if (address > 2)
325 return -EINVAL;
326
327 ret = i2c_smbus_read_byte_data(client, address);
328 if (ret < 0)
329 dev_err(&client->dev, "register read failed\n");
330
331 return ret;
332}
333
334static int stk8312_read_raw(struct iio_dev *indio_dev,
335 struct iio_chan_spec const *chan,
336 int *val, int *val2, long mask)
337{
338 struct stk8312_data *data = iio_priv(indio_dev);
339 int ret;
340
341 switch (mask) {
342 case IIO_CHAN_INFO_RAW:
343 if (iio_buffer_enabled(indio_dev))
344 return -EBUSY;
345 mutex_lock(&data->lock);
346 ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
347 if (ret < 0) {
348 mutex_unlock(&data->lock);
349 return ret;
350 }
351 ret = stk8312_read_accel(data, chan->address);
352 if (ret < 0) {
353 stk8312_set_mode(data,
354 data->mode & (~STK8312_MODE_ACTIVE));
355 mutex_unlock(&data->lock);
356 return ret;
357 }
358 *val = sign_extend32(ret, 7);
359 ret = stk8312_set_mode(data,
360 data->mode & (~STK8312_MODE_ACTIVE));
361 mutex_unlock(&data->lock);
362 if (ret < 0)
363 return ret;
364 return IIO_VAL_INT;
365 case IIO_CHAN_INFO_SCALE:
366 *val = stk8312_scale_table[data->range - 1][0];
367 *val2 = stk8312_scale_table[data->range - 1][1];
368 return IIO_VAL_INT_PLUS_MICRO;
369 case IIO_CHAN_INFO_SAMP_FREQ:
370 *val = stk8312_samp_freq_table[data->sample_rate_idx].val;
371 *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2;
372 return IIO_VAL_INT_PLUS_MICRO;
373 }
374
375 return -EINVAL;
376}
377
378static int stk8312_write_raw(struct iio_dev *indio_dev,
379 struct iio_chan_spec const *chan,
380 int val, int val2, long mask)
381{
382 int i;
383 int index = -1;
384 int ret;
385 struct stk8312_data *data = iio_priv(indio_dev);
386
387 switch (mask) {
388 case IIO_CHAN_INFO_SCALE:
389 for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
390 if (val == stk8312_scale_table[i][0] &&
391 val2 == stk8312_scale_table[i][1]) {
392 index = i + 1;
393 break;
394 }
395 if (index < 0)
396 return -EINVAL;
397
398 mutex_lock(&data->lock);
399 ret = stk8312_set_range(data, index);
400 mutex_unlock(&data->lock);
401
402 return ret;
403 case IIO_CHAN_INFO_SAMP_FREQ:
404 for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++)
405 if (val == stk8312_samp_freq_table[i].val &&
406 val2 == stk8312_samp_freq_table[i].val2) {
407 index = i;
408 break;
409 }
410 if (index < 0)
411 return -EINVAL;
412 mutex_lock(&data->lock);
413 ret = stk8312_set_sample_rate(data, index);
414 mutex_unlock(&data->lock);
415
416 return ret;
417 }
418
419 return -EINVAL;
420}
421
422static const struct iio_info stk8312_info = {
423 .read_raw = stk8312_read_raw,
424 .write_raw = stk8312_write_raw,
425 .attrs = &stk8312_attribute_group,
426};
427
428static irqreturn_t stk8312_trigger_handler(int irq, void *p)
429{
430 struct iio_poll_func *pf = p;
431 struct iio_dev *indio_dev = pf->indio_dev;
432 struct stk8312_data *data = iio_priv(indio_dev);
433 int bit, ret, i = 0;
434
435 mutex_lock(&data->lock);
436
437
438
439
440 if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) {
441 ret = i2c_smbus_read_i2c_block_data(data->client,
442 STK8312_REG_XOUT,
443 STK8312_ALL_CHANNEL_SIZE,
444 data->scan.chans);
445 if (ret < STK8312_ALL_CHANNEL_SIZE) {
446 dev_err(&data->client->dev, "register read failed\n");
447 mutex_unlock(&data->lock);
448 goto err;
449 }
450 } else {
451 for_each_set_bit(bit, indio_dev->active_scan_mask,
452 indio_dev->masklength) {
453 ret = stk8312_read_accel(data, bit);
454 if (ret < 0) {
455 mutex_unlock(&data->lock);
456 goto err;
457 }
458 data->scan.chans[i++] = ret;
459 }
460 }
461 mutex_unlock(&data->lock);
462
463 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
464 pf->timestamp);
465err:
466 iio_trigger_notify_done(indio_dev->trig);
467
468 return IRQ_HANDLED;
469}
470
471static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)
472{
473 struct iio_dev *indio_dev = private;
474 struct stk8312_data *data = iio_priv(indio_dev);
475
476 if (data->dready_trigger_on)
477 iio_trigger_poll(data->dready_trig);
478
479 return IRQ_HANDLED;
480}
481
482static int stk8312_buffer_preenable(struct iio_dev *indio_dev)
483{
484 struct stk8312_data *data = iio_priv(indio_dev);
485
486 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
487}
488
489static int stk8312_buffer_postdisable(struct iio_dev *indio_dev)
490{
491 struct stk8312_data *data = iio_priv(indio_dev);
492
493 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
494}
495
496static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {
497 .preenable = stk8312_buffer_preenable,
498 .postdisable = stk8312_buffer_postdisable,
499};
500
501static int stk8312_probe(struct i2c_client *client,
502 const struct i2c_device_id *id)
503{
504 int ret;
505 struct iio_dev *indio_dev;
506 struct stk8312_data *data;
507
508 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
509 if (!indio_dev) {
510 dev_err(&client->dev, "iio allocation failed!\n");
511 return -ENOMEM;
512 }
513
514 data = iio_priv(indio_dev);
515 data->client = client;
516 i2c_set_clientdata(client, indio_dev);
517 mutex_init(&data->lock);
518
519 indio_dev->info = &stk8312_info;
520 indio_dev->name = STK8312_DRIVER_NAME;
521 indio_dev->modes = INDIO_DIRECT_MODE;
522 indio_dev->channels = stk8312_channels;
523 indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);
524
525
526 ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
527 if (ret < 0) {
528 dev_err(&client->dev, "failed to reset sensor\n");
529 return ret;
530 }
531 data->sample_rate_idx = STK8312_SR_400HZ_IDX;
532 ret = stk8312_set_range(data, STK8312_RNG_6G);
533 if (ret < 0)
534 return ret;
535
536 ret = stk8312_set_mode(data,
537 STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE);
538 if (ret < 0)
539 return ret;
540
541 if (client->irq > 0) {
542 ret = devm_request_threaded_irq(&client->dev, client->irq,
543 stk8312_data_rdy_trig_poll,
544 NULL,
545 IRQF_TRIGGER_RISING |
546 IRQF_ONESHOT,
547 STK8312_IRQ_NAME,
548 indio_dev);
549 if (ret < 0) {
550 dev_err(&client->dev, "request irq %d failed\n",
551 client->irq);
552 goto err_power_off;
553 }
554
555 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
556 "%s-dev%d",
557 indio_dev->name,
558 iio_device_id(indio_dev));
559 if (!data->dready_trig) {
560 ret = -ENOMEM;
561 goto err_power_off;
562 }
563
564 data->dready_trig->ops = &stk8312_trigger_ops;
565 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
566 ret = iio_trigger_register(data->dready_trig);
567 if (ret) {
568 dev_err(&client->dev, "iio trigger register failed\n");
569 goto err_power_off;
570 }
571 }
572
573 ret = iio_triggered_buffer_setup(indio_dev,
574 iio_pollfunc_store_time,
575 stk8312_trigger_handler,
576 &stk8312_buffer_setup_ops);
577 if (ret < 0) {
578 dev_err(&client->dev, "iio triggered buffer setup failed\n");
579 goto err_trigger_unregister;
580 }
581
582 ret = iio_device_register(indio_dev);
583 if (ret < 0) {
584 dev_err(&client->dev, "device_register failed\n");
585 goto err_buffer_cleanup;
586 }
587
588 return 0;
589
590err_buffer_cleanup:
591 iio_triggered_buffer_cleanup(indio_dev);
592err_trigger_unregister:
593 if (data->dready_trig)
594 iio_trigger_unregister(data->dready_trig);
595err_power_off:
596 stk8312_set_mode(data, STK8312_MODE_STANDBY);
597 return ret;
598}
599
600static int stk8312_remove(struct i2c_client *client)
601{
602 struct iio_dev *indio_dev = i2c_get_clientdata(client);
603 struct stk8312_data *data = iio_priv(indio_dev);
604
605 iio_device_unregister(indio_dev);
606 iio_triggered_buffer_cleanup(indio_dev);
607
608 if (data->dready_trig)
609 iio_trigger_unregister(data->dready_trig);
610
611 return stk8312_set_mode(data, STK8312_MODE_STANDBY);
612}
613
614#ifdef CONFIG_PM_SLEEP
615static int stk8312_suspend(struct device *dev)
616{
617 struct stk8312_data *data;
618
619 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
620
621 return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
622}
623
624static int stk8312_resume(struct device *dev)
625{
626 struct stk8312_data *data;
627
628 data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
629
630 return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
631}
632
633static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
634
635#define STK8312_PM_OPS (&stk8312_pm_ops)
636#else
637#define STK8312_PM_OPS NULL
638#endif
639
640static const struct i2c_device_id stk8312_i2c_id[] = {
641
642 { "STK8312", 0 },
643 { "stk8312", 0 },
644 {}
645};
646MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);
647
648static struct i2c_driver stk8312_driver = {
649 .driver = {
650 .name = STK8312_DRIVER_NAME,
651 .pm = STK8312_PM_OPS,
652 },
653 .probe = stk8312_probe,
654 .remove = stk8312_remove,
655 .id_table = stk8312_i2c_id,
656};
657
658module_i2c_driver(stk8312_driver);
659
660MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
661MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
662MODULE_LICENSE("GPL v2");
663
