GNU Linux-libre 5.16.19-gnu
[releases.git] / drivers / iio / accel / stk8312.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Sensortek STK8312 3-Axis Accelerometer
4  *
5  * Copyright (c) 2015, Intel Corporation.
6  *
7  * IIO driver for STK8312; 7-bit I2C address: 0x3D.
8  */
9
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    /* active-high, push-pull */
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  * The accelerometer has two measurement ranges:
52  *
53  * -6g - +6g (8-bit, signed)
54  * -16g - +16g (8-bit, signed)
55  *
56  * scale1 = (6 + 6) * 9.81 / (2^8 - 1)     = 0.4616
57  * scale2 = (16 + 16) * 9.81 / (2^8 - 1)   = 1.2311
58  */
59 #define STK8312_SCALE_AVAIL             "0.4616 1.2311"
60
61 static const int stk8312_scale_table[][2] = {
62         {0, 461600}, {1, 231100}
63 };
64
65 static 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
90 static 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
97 struct 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         /* Ensure timestamp is naturally aligned */
106         struct {
107                 s8 chans[3];
108                 s64 timestamp __aligned(8);
109         } scan;
110 };
111
112 static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
113
114 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");
115
116 static 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
122 static const struct attribute_group stk8312_attribute_group = {
123         .attrs = stk8312_attributes
124 };
125
126 static 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
165 exit_err:
166         dev_err(&client->dev, "failed to initialize sensor\n");
167         return ret;
168 }
169
170 static 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                 /* Need to run OTP sequence before entering active mode */
187                 usleep_range(1000, 5000);
188                 ret = stk8312_otp_init(data);
189         }
190
191         return ret;
192 }
193
194 static 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         /* We need to go in standby mode to modify registers */
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
216 static 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
238 static const struct iio_trigger_ops stk8312_trigger_ops = {
239         .set_trigger_state = stk8312_data_rdy_trigger_set_state,
240 };
241
242 static 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         /* We need to go in standby mode to modify registers */
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
272 err_activate:
273         dev_err(&client->dev, "failed to set sampling rate\n");
274         stk8312_set_mode(data, mode);
275
276         return ret;
277 }
278
279 static 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         /* We need to go in standby mode to modify registers */
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
312 err_activate:
313         dev_err(&client->dev, "failed to change sensor range\n");
314         stk8312_set_mode(data, mode);
315
316         return ret;
317 }
318
319 static 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
334 static 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
378 static 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
422 static 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
428 static 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          * Do a bulk read if all channels are requested,
438          * from 0x00 (XOUT) to 0x02 (ZOUT)
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);
465 err:
466         iio_trigger_notify_done(indio_dev->trig);
467
468         return IRQ_HANDLED;
469 }
470
471 static 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
482 static 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
489 static 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
496 static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {
497         .preenable   = stk8312_buffer_preenable,
498         .postdisable = stk8312_buffer_postdisable,
499 };
500
501 static 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         /* A software reset is recommended at power-on */
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
590 err_buffer_cleanup:
591         iio_triggered_buffer_cleanup(indio_dev);
592 err_trigger_unregister:
593         if (data->dready_trig)
594                 iio_trigger_unregister(data->dready_trig);
595 err_power_off:
596         stk8312_set_mode(data, STK8312_MODE_STANDBY);
597         return ret;
598 }
599
600 static 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
615 static 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
624 static 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
633 static 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
640 static const struct i2c_device_id stk8312_i2c_id[] = {
641         /* Deprecated in favour of lowercase form */
642         { "STK8312", 0 },
643         { "stk8312", 0 },
644         {}
645 };
646 MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);
647
648 static 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
658 module_i2c_driver(stk8312_driver);
659
660 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
661 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
662 MODULE_LICENSE("GPL v2");