Linux-libre 5.3.12-gnu
[librecmc/linux-libre.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/acpi.h>
11 #include <linux/i2c.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/delay.h>
16 #include <linux/iio/buffer.h>
17 #include <linux/iio/iio.h>
18 #include <linux/iio/sysfs.h>
19 #include <linux/iio/trigger.h>
20 #include <linux/iio/triggered_buffer.h>
21 #include <linux/iio/trigger_consumer.h>
22
23 #define STK8312_REG_XOUT                0x00
24 #define STK8312_REG_YOUT                0x01
25 #define STK8312_REG_ZOUT                0x02
26 #define STK8312_REG_INTSU               0x06
27 #define STK8312_REG_MODE                0x07
28 #define STK8312_REG_SR                  0x08
29 #define STK8312_REG_STH                 0x13
30 #define STK8312_REG_RESET               0x20
31 #define STK8312_REG_AFECTRL             0x24
32 #define STK8312_REG_OTPADDR             0x3D
33 #define STK8312_REG_OTPDATA             0x3E
34 #define STK8312_REG_OTPCTRL             0x3F
35
36 #define STK8312_MODE_ACTIVE             BIT(0)
37 #define STK8312_MODE_STANDBY            0x00
38 #define STK8312_MODE_INT_AH_PP          0xC0    /* active-high, push-pull */
39 #define STK8312_DREADY_BIT              BIT(4)
40 #define STK8312_RNG_6G                  1
41 #define STK8312_RNG_SHIFT               6
42 #define STK8312_RNG_MASK                GENMASK(7, 6)
43 #define STK8312_SR_MASK                 GENMASK(2, 0)
44 #define STK8312_SR_400HZ_IDX            0
45 #define STK8312_ALL_CHANNEL_MASK        GENMASK(2, 0)
46 #define STK8312_ALL_CHANNEL_SIZE        3
47
48 #define STK8312_DRIVER_NAME             "stk8312"
49 #define STK8312_IRQ_NAME                "stk8312_event"
50
51 /*
52  * The accelerometer has two measurement ranges:
53  *
54  * -6g - +6g (8-bit, signed)
55  * -16g - +16g (8-bit, signed)
56  *
57  * scale1 = (6 + 6) * 9.81 / (2^8 - 1)     = 0.4616
58  * scale2 = (16 + 16) * 9.81 / (2^8 - 1)   = 1.2311
59  */
60 #define STK8312_SCALE_AVAIL             "0.4616 1.2311"
61
62 static const int stk8312_scale_table[][2] = {
63         {0, 461600}, {1, 231100}
64 };
65
66 static const struct {
67         int val;
68         int val2;
69 } stk8312_samp_freq_table[] = {
70         {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0},
71         {12, 500000}, {6, 250000}, {3, 125000}
72 };
73
74 #define STK8312_ACCEL_CHANNEL(index, reg, axis) {                       \
75         .type = IIO_ACCEL,                                              \
76         .address = reg,                                                 \
77         .modified = 1,                                                  \
78         .channel2 = IIO_MOD_##axis,                                     \
79         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
80         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |          \
81                                     BIT(IIO_CHAN_INFO_SAMP_FREQ),       \
82         .scan_index = index,                                            \
83         .scan_type = {                                                  \
84                 .sign = 's',                                            \
85                 .realbits = 8,                                          \
86                 .storagebits = 8,                                       \
87                 .endianness = IIO_CPU,                                  \
88         },                                                              \
89 }
90
91 static const struct iio_chan_spec stk8312_channels[] = {
92         STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X),
93         STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y),
94         STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z),
95         IIO_CHAN_SOFT_TIMESTAMP(3),
96 };
97
98 struct stk8312_data {
99         struct i2c_client *client;
100         struct mutex lock;
101         u8 range;
102         u8 sample_rate_idx;
103         u8 mode;
104         struct iio_trigger *dready_trig;
105         bool dready_trigger_on;
106         s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 64-bit timestamp */
107 };
108
109 static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
110
111 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");
112
113 static struct attribute *stk8312_attributes[] = {
114         &iio_const_attr_in_accel_scale_available.dev_attr.attr,
115         &iio_const_attr_sampling_frequency_available.dev_attr.attr,
116         NULL,
117 };
118
119 static const struct attribute_group stk8312_attribute_group = {
120         .attrs = stk8312_attributes
121 };
122
123 static int stk8312_otp_init(struct stk8312_data *data)
124 {
125         int ret;
126         int count = 10;
127         struct i2c_client *client = data->client;
128
129         ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
130         if (ret < 0)
131                 goto exit_err;
132         ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
133         if (ret < 0)
134                 goto exit_err;
135
136         do {
137                 usleep_range(1000, 5000);
138                 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
139                 if (ret < 0)
140                         goto exit_err;
141                 count--;
142         } while (!(ret & BIT(7)) && count > 0);
143
144         if (count == 0) {
145                 ret = -ETIMEDOUT;
146                 goto exit_err;
147         }
148
149         ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
150         if (ret == 0)
151                 ret = -EINVAL;
152         if (ret < 0)
153                 goto exit_err;
154
155         ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_AFECTRL, ret);
156         if (ret < 0)
157                 goto exit_err;
158         msleep(150);
159
160         return 0;
161
162 exit_err:
163         dev_err(&client->dev, "failed to initialize sensor\n");
164         return ret;
165 }
166
167 static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
168 {
169         int ret;
170         struct i2c_client *client = data->client;
171
172         if (mode == data->mode)
173                 return 0;
174
175         ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode);
176         if (ret < 0) {
177                 dev_err(&client->dev, "failed to change sensor mode\n");
178                 return ret;
179         }
180
181         data->mode = mode;
182         if (mode & STK8312_MODE_ACTIVE) {
183                 /* Need to run OTP sequence before entering active mode */
184                 usleep_range(1000, 5000);
185                 ret = stk8312_otp_init(data);
186         }
187
188         return ret;
189 }
190
191 static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask)
192 {
193         int ret;
194         u8 mode;
195         struct i2c_client *client = data->client;
196
197         mode = data->mode;
198         /* We need to go in standby mode to modify registers */
199         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
200         if (ret < 0)
201                 return ret;
202
203         ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask);
204         if (ret < 0) {
205                 dev_err(&client->dev, "failed to set interrupts\n");
206                 stk8312_set_mode(data, mode);
207                 return ret;
208         }
209
210         return stk8312_set_mode(data, mode);
211 }
212
213 static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig,
214                                               bool state)
215 {
216         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
217         struct stk8312_data *data = iio_priv(indio_dev);
218         int ret;
219
220         if (state)
221                 ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT);
222         else
223                 ret = stk8312_set_interrupts(data, 0x00);
224
225         if (ret < 0) {
226                 dev_err(&data->client->dev, "failed to set trigger state\n");
227                 return ret;
228         }
229
230         data->dready_trigger_on = state;
231
232         return 0;
233 }
234
235 static const struct iio_trigger_ops stk8312_trigger_ops = {
236         .set_trigger_state = stk8312_data_rdy_trigger_set_state,
237 };
238
239 static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate)
240 {
241         int ret;
242         u8 masked_reg;
243         u8 mode;
244         struct i2c_client *client = data->client;
245
246         if (rate == data->sample_rate_idx)
247                 return 0;
248
249         mode = data->mode;
250         /* We need to go in standby mode to modify registers */
251         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
252         if (ret < 0)
253                 return ret;
254
255         ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR);
256         if (ret < 0)
257                 goto err_activate;
258
259         masked_reg = (ret & (~STK8312_SR_MASK)) | rate;
260
261         ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg);
262         if (ret < 0)
263                 goto err_activate;
264
265         data->sample_rate_idx = rate;
266
267         return stk8312_set_mode(data, mode);
268
269 err_activate:
270         dev_err(&client->dev, "failed to set sampling rate\n");
271         stk8312_set_mode(data, mode);
272
273         return ret;
274 }
275
276 static int stk8312_set_range(struct stk8312_data *data, u8 range)
277 {
278         int ret;
279         u8 masked_reg;
280         u8 mode;
281         struct i2c_client *client = data->client;
282
283         if (range != 1 && range != 2)
284                 return -EINVAL;
285         else if (range == data->range)
286                 return 0;
287
288         mode = data->mode;
289         /* We need to go in standby mode to modify registers */
290         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
291         if (ret < 0)
292                 return ret;
293
294         ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
295         if (ret < 0)
296                 goto err_activate;
297
298         masked_reg = ret & (~STK8312_RNG_MASK);
299         masked_reg |= range << STK8312_RNG_SHIFT;
300
301         ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
302         if (ret < 0)
303                 goto err_activate;
304
305         data->range = range;
306
307         return stk8312_set_mode(data, mode);
308
309 err_activate:
310         dev_err(&client->dev, "failed to change sensor range\n");
311         stk8312_set_mode(data, mode);
312
313         return ret;
314 }
315
316 static int stk8312_read_accel(struct stk8312_data *data, u8 address)
317 {
318         int ret;
319         struct i2c_client *client = data->client;
320
321         if (address > 2)
322                 return -EINVAL;
323
324         ret = i2c_smbus_read_byte_data(client, address);
325         if (ret < 0)
326                 dev_err(&client->dev, "register read failed\n");
327
328         return ret;
329 }
330
331 static int stk8312_read_raw(struct iio_dev *indio_dev,
332                             struct iio_chan_spec const *chan,
333                             int *val, int *val2, long mask)
334 {
335         struct stk8312_data *data = iio_priv(indio_dev);
336         int ret;
337
338         switch (mask) {
339         case IIO_CHAN_INFO_RAW:
340                 if (iio_buffer_enabled(indio_dev))
341                         return -EBUSY;
342                 mutex_lock(&data->lock);
343                 ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
344                 if (ret < 0) {
345                         mutex_unlock(&data->lock);
346                         return ret;
347                 }
348                 ret = stk8312_read_accel(data, chan->address);
349                 if (ret < 0) {
350                         stk8312_set_mode(data,
351                                          data->mode & (~STK8312_MODE_ACTIVE));
352                         mutex_unlock(&data->lock);
353                         return ret;
354                 }
355                 *val = sign_extend32(ret, 7);
356                 ret = stk8312_set_mode(data,
357                                        data->mode & (~STK8312_MODE_ACTIVE));
358                 mutex_unlock(&data->lock);
359                 if (ret < 0)
360                         return ret;
361                 return IIO_VAL_INT;
362         case IIO_CHAN_INFO_SCALE:
363                 *val = stk8312_scale_table[data->range - 1][0];
364                 *val2 = stk8312_scale_table[data->range - 1][1];
365                 return IIO_VAL_INT_PLUS_MICRO;
366         case IIO_CHAN_INFO_SAMP_FREQ:
367                 *val = stk8312_samp_freq_table[data->sample_rate_idx].val;
368                 *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2;
369                 return IIO_VAL_INT_PLUS_MICRO;
370         }
371
372         return -EINVAL;
373 }
374
375 static int stk8312_write_raw(struct iio_dev *indio_dev,
376                              struct iio_chan_spec const *chan,
377                              int val, int val2, long mask)
378 {
379         int i;
380         int index = -1;
381         int ret;
382         struct stk8312_data *data = iio_priv(indio_dev);
383
384         switch (mask) {
385         case IIO_CHAN_INFO_SCALE:
386                 for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
387                         if (val == stk8312_scale_table[i][0] &&
388                             val2 == stk8312_scale_table[i][1]) {
389                                 index = i + 1;
390                                 break;
391                         }
392                 if (index < 0)
393                         return -EINVAL;
394
395                 mutex_lock(&data->lock);
396                 ret = stk8312_set_range(data, index);
397                 mutex_unlock(&data->lock);
398
399                 return ret;
400         case IIO_CHAN_INFO_SAMP_FREQ:
401                 for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++)
402                         if (val == stk8312_samp_freq_table[i].val &&
403                             val2 == stk8312_samp_freq_table[i].val2) {
404                                 index = i;
405                                 break;
406                         }
407                 if (index < 0)
408                         return -EINVAL;
409                 mutex_lock(&data->lock);
410                 ret = stk8312_set_sample_rate(data, index);
411                 mutex_unlock(&data->lock);
412
413                 return ret;
414         }
415
416         return -EINVAL;
417 }
418
419 static const struct iio_info stk8312_info = {
420         .read_raw               = stk8312_read_raw,
421         .write_raw              = stk8312_write_raw,
422         .attrs                  = &stk8312_attribute_group,
423 };
424
425 static irqreturn_t stk8312_trigger_handler(int irq, void *p)
426 {
427         struct iio_poll_func *pf = p;
428         struct iio_dev *indio_dev = pf->indio_dev;
429         struct stk8312_data *data = iio_priv(indio_dev);
430         int bit, ret, i = 0;
431
432         mutex_lock(&data->lock);
433         /*
434          * Do a bulk read if all channels are requested,
435          * from 0x00 (XOUT) to 0x02 (ZOUT)
436          */
437         if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) {
438                 ret = i2c_smbus_read_i2c_block_data(data->client,
439                                                     STK8312_REG_XOUT,
440                                                     STK8312_ALL_CHANNEL_SIZE,
441                                                     data->buffer);
442                 if (ret < STK8312_ALL_CHANNEL_SIZE) {
443                         dev_err(&data->client->dev, "register read failed\n");
444                         mutex_unlock(&data->lock);
445                         goto err;
446                 }
447         } else {
448                 for_each_set_bit(bit, indio_dev->active_scan_mask,
449                                  indio_dev->masklength) {
450                         ret = stk8312_read_accel(data, bit);
451                         if (ret < 0) {
452                                 mutex_unlock(&data->lock);
453                                 goto err;
454                         }
455                         data->buffer[i++] = ret;
456                 }
457         }
458         mutex_unlock(&data->lock);
459
460         iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
461                                            pf->timestamp);
462 err:
463         iio_trigger_notify_done(indio_dev->trig);
464
465         return IRQ_HANDLED;
466 }
467
468 static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)
469 {
470         struct iio_dev *indio_dev = private;
471         struct stk8312_data *data = iio_priv(indio_dev);
472
473         if (data->dready_trigger_on)
474                 iio_trigger_poll(data->dready_trig);
475
476         return IRQ_HANDLED;
477 }
478
479 static int stk8312_buffer_preenable(struct iio_dev *indio_dev)
480 {
481         struct stk8312_data *data = iio_priv(indio_dev);
482
483         return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
484 }
485
486 static int stk8312_buffer_postdisable(struct iio_dev *indio_dev)
487 {
488         struct stk8312_data *data = iio_priv(indio_dev);
489
490         return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
491 }
492
493 static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {
494         .preenable   = stk8312_buffer_preenable,
495         .postenable  = iio_triggered_buffer_postenable,
496         .predisable  = iio_triggered_buffer_predisable,
497         .postdisable = stk8312_buffer_postdisable,
498 };
499
500 static int stk8312_probe(struct i2c_client *client,
501                          const struct i2c_device_id *id)
502 {
503         int ret;
504         struct iio_dev *indio_dev;
505         struct stk8312_data *data;
506
507         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
508         if (!indio_dev) {
509                 dev_err(&client->dev, "iio allocation failed!\n");
510                 return -ENOMEM;
511         }
512
513         data = iio_priv(indio_dev);
514         data->client = client;
515         i2c_set_clientdata(client, indio_dev);
516         mutex_init(&data->lock);
517
518         indio_dev->dev.parent = &client->dev;
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                                                            indio_dev->id);
559                 if (!data->dready_trig) {
560                         ret = -ENOMEM;
561                         goto err_power_off;
562                 }
563
564                 data->dready_trig->dev.parent = &client->dev;
565                 data->dready_trig->ops = &stk8312_trigger_ops;
566                 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
567                 ret = iio_trigger_register(data->dready_trig);
568                 if (ret) {
569                         dev_err(&client->dev, "iio trigger register failed\n");
570                         goto err_power_off;
571                 }
572         }
573
574         ret = iio_triggered_buffer_setup(indio_dev,
575                                          iio_pollfunc_store_time,
576                                          stk8312_trigger_handler,
577                                          &stk8312_buffer_setup_ops);
578         if (ret < 0) {
579                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
580                 goto err_trigger_unregister;
581         }
582
583         ret = iio_device_register(indio_dev);
584         if (ret < 0) {
585                 dev_err(&client->dev, "device_register failed\n");
586                 goto err_buffer_cleanup;
587         }
588
589         return 0;
590
591 err_buffer_cleanup:
592         iio_triggered_buffer_cleanup(indio_dev);
593 err_trigger_unregister:
594         if (data->dready_trig)
595                 iio_trigger_unregister(data->dready_trig);
596 err_power_off:
597         stk8312_set_mode(data, STK8312_MODE_STANDBY);
598         return ret;
599 }
600
601 static int stk8312_remove(struct i2c_client *client)
602 {
603         struct iio_dev *indio_dev = i2c_get_clientdata(client);
604         struct stk8312_data *data = iio_priv(indio_dev);
605
606         iio_device_unregister(indio_dev);
607         iio_triggered_buffer_cleanup(indio_dev);
608
609         if (data->dready_trig)
610                 iio_trigger_unregister(data->dready_trig);
611
612         return stk8312_set_mode(data, STK8312_MODE_STANDBY);
613 }
614
615 #ifdef CONFIG_PM_SLEEP
616 static int stk8312_suspend(struct device *dev)
617 {
618         struct stk8312_data *data;
619
620         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
621
622         return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
623 }
624
625 static int stk8312_resume(struct device *dev)
626 {
627         struct stk8312_data *data;
628
629         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
630
631         return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
632 }
633
634 static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
635
636 #define STK8312_PM_OPS (&stk8312_pm_ops)
637 #else
638 #define STK8312_PM_OPS NULL
639 #endif
640
641 static const struct i2c_device_id stk8312_i2c_id[] = {
642         {"STK8312", 0},
643         {}
644 };
645 MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);
646
647 static const struct acpi_device_id stk8312_acpi_id[] = {
648         {"STK8312", 0},
649         {}
650 };
651
652 MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
653
654 static struct i2c_driver stk8312_driver = {
655         .driver = {
656                 .name = STK8312_DRIVER_NAME,
657                 .pm = STK8312_PM_OPS,
658                 .acpi_match_table = ACPI_PTR(stk8312_acpi_id),
659         },
660         .probe =            stk8312_probe,
661         .remove =           stk8312_remove,
662         .id_table =         stk8312_i2c_id,
663 };
664
665 module_i2c_driver(stk8312_driver);
666
667 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
668 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
669 MODULE_LICENSE("GPL v2");