These changes are the raw update to linux-4.4.6-rt14. Kernel sources
[kvmfornfv.git] / kernel / drivers / iio / accel / stk8312.c
1 /**
2  * Sensortek STK8312 3-Axis Accelerometer
3  *
4  * Copyright (c) 2015, Intel Corporation.
5  *
6  * This file is subject to the terms and conditions of version 2 of
7  * the GNU General Public License. See the file COPYING in the main
8  * directory of this archive for more details.
9  *
10  * IIO driver for STK8312; 7-bit I2C address: 0x3D.
11  */
12
13 #include <linux/acpi.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/i2c.h>
16 #include <linux/interrupt.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/delay.h>
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/trigger.h>
24 #include <linux/iio/triggered_buffer.h>
25 #include <linux/iio/trigger_consumer.h>
26
27 #define STK8312_REG_XOUT                0x00
28 #define STK8312_REG_YOUT                0x01
29 #define STK8312_REG_ZOUT                0x02
30 #define STK8312_REG_INTSU               0x06
31 #define STK8312_REG_MODE                0x07
32 #define STK8312_REG_SR                  0x08
33 #define STK8312_REG_STH                 0x13
34 #define STK8312_REG_RESET               0x20
35 #define STK8312_REG_AFECTRL             0x24
36 #define STK8312_REG_OTPADDR             0x3D
37 #define STK8312_REG_OTPDATA             0x3E
38 #define STK8312_REG_OTPCTRL             0x3F
39
40 #define STK8312_MODE_ACTIVE             BIT(0)
41 #define STK8312_MODE_STANDBY            0x00
42 #define STK8312_MODE_INT_AH_PP          0xC0    /* active-high, push-pull */
43 #define STK8312_DREADY_BIT              BIT(4)
44 #define STK8312_RNG_6G                  1
45 #define STK8312_RNG_SHIFT               6
46 #define STK8312_RNG_MASK                GENMASK(7, 6)
47 #define STK8312_SR_MASK                 GENMASK(2, 0)
48 #define STK8312_SR_400HZ_IDX            0
49 #define STK8312_ALL_CHANNEL_MASK        GENMASK(2, 0)
50 #define STK8312_ALL_CHANNEL_SIZE        3
51
52 #define STK8312_DRIVER_NAME             "stk8312"
53 #define STK8312_IRQ_NAME                "stk8312_event"
54
55 /*
56  * The accelerometer has two measurement ranges:
57  *
58  * -6g - +6g (8-bit, signed)
59  * -16g - +16g (8-bit, signed)
60  *
61  * scale1 = (6 + 6) * 9.81 / (2^8 - 1)     = 0.4616
62  * scale2 = (16 + 16) * 9.81 / (2^8 - 1)   = 1.2311
63  */
64 #define STK8312_SCALE_AVAIL             "0.4616 1.2311"
65
66 static const int stk8312_scale_table[][2] = {
67         {0, 461600}, {1, 231100}
68 };
69
70 static const struct {
71         int val;
72         int val2;
73 } stk8312_samp_freq_table[] = {
74         {400, 0}, {200, 0}, {100, 0}, {50, 0}, {25, 0},
75         {12, 500000}, {6, 250000}, {3, 125000}
76 };
77
78 #define STK8312_ACCEL_CHANNEL(index, reg, axis) {                       \
79         .type = IIO_ACCEL,                                              \
80         .address = reg,                                                 \
81         .modified = 1,                                                  \
82         .channel2 = IIO_MOD_##axis,                                     \
83         .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),                   \
84         .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |          \
85                                     BIT(IIO_CHAN_INFO_SAMP_FREQ),       \
86         .scan_index = index,                                            \
87         .scan_type = {                                                  \
88                 .sign = 's',                                            \
89                 .realbits = 8,                                          \
90                 .storagebits = 8,                                       \
91                 .endianness = IIO_CPU,                                  \
92         },                                                              \
93 }
94
95 static const struct iio_chan_spec stk8312_channels[] = {
96         STK8312_ACCEL_CHANNEL(0, STK8312_REG_XOUT, X),
97         STK8312_ACCEL_CHANNEL(1, STK8312_REG_YOUT, Y),
98         STK8312_ACCEL_CHANNEL(2, STK8312_REG_ZOUT, Z),
99         IIO_CHAN_SOFT_TIMESTAMP(3),
100 };
101
102 struct stk8312_data {
103         struct i2c_client *client;
104         struct mutex lock;
105         u8 range;
106         u8 sample_rate_idx;
107         u8 mode;
108         struct iio_trigger *dready_trig;
109         bool dready_trigger_on;
110         s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 64-bit timestamp */
111 };
112
113 static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
114
115 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("3.125 6.25 12.5 25 50 100 200 400");
116
117 static struct attribute *stk8312_attributes[] = {
118         &iio_const_attr_in_accel_scale_available.dev_attr.attr,
119         &iio_const_attr_sampling_frequency_available.dev_attr.attr,
120         NULL,
121 };
122
123 static const struct attribute_group stk8312_attribute_group = {
124         .attrs = stk8312_attributes
125 };
126
127 static int stk8312_otp_init(struct stk8312_data *data)
128 {
129         int ret;
130         int count = 10;
131         struct i2c_client *client = data->client;
132
133         ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
134         if (ret < 0)
135                 goto exit_err;
136         ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
137         if (ret < 0)
138                 goto exit_err;
139
140         do {
141                 usleep_range(1000, 5000);
142                 ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
143                 if (ret < 0)
144                         goto exit_err;
145                 count--;
146         } while (!(ret & BIT(7)) && count > 0);
147
148         if (count == 0) {
149                 ret = -ETIMEDOUT;
150                 goto exit_err;
151         }
152
153         ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
154         if (ret == 0)
155                 ret = -EINVAL;
156         if (ret < 0)
157                 goto exit_err;
158
159         ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_AFECTRL, ret);
160         if (ret < 0)
161                 goto exit_err;
162         msleep(150);
163
164         return 0;
165
166 exit_err:
167         dev_err(&client->dev, "failed to initialize sensor\n");
168         return ret;
169 }
170
171 static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
172 {
173         int ret;
174         struct i2c_client *client = data->client;
175
176         if (mode == data->mode)
177                 return 0;
178
179         ret = i2c_smbus_write_byte_data(client, STK8312_REG_MODE, mode);
180         if (ret < 0) {
181                 dev_err(&client->dev, "failed to change sensor mode\n");
182                 return ret;
183         }
184
185         data->mode = mode;
186         if (mode & STK8312_MODE_ACTIVE) {
187                 /* Need to run OTP sequence before entering active mode */
188                 usleep_range(1000, 5000);
189                 ret = stk8312_otp_init(data);
190         }
191
192         return ret;
193 }
194
195 static int stk8312_set_interrupts(struct stk8312_data *data, u8 int_mask)
196 {
197         int ret;
198         u8 mode;
199         struct i2c_client *client = data->client;
200
201         mode = data->mode;
202         /* We need to go in standby mode to modify registers */
203         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
204         if (ret < 0)
205                 return ret;
206
207         ret = i2c_smbus_write_byte_data(client, STK8312_REG_INTSU, int_mask);
208         if (ret < 0) {
209                 dev_err(&client->dev, "failed to set interrupts\n");
210                 stk8312_set_mode(data, mode);
211                 return ret;
212         }
213
214         return stk8312_set_mode(data, mode);
215 }
216
217 static int stk8312_data_rdy_trigger_set_state(struct iio_trigger *trig,
218                                               bool state)
219 {
220         struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
221         struct stk8312_data *data = iio_priv(indio_dev);
222         int ret;
223
224         if (state)
225                 ret = stk8312_set_interrupts(data, STK8312_DREADY_BIT);
226         else
227                 ret = stk8312_set_interrupts(data, 0x00);
228
229         if (ret < 0) {
230                 dev_err(&data->client->dev, "failed to set trigger state\n");
231                 return ret;
232         }
233
234         data->dready_trigger_on = state;
235
236         return 0;
237 }
238
239 static const struct iio_trigger_ops stk8312_trigger_ops = {
240         .set_trigger_state = stk8312_data_rdy_trigger_set_state,
241         .owner = THIS_MODULE,
242 };
243
244 static int stk8312_set_sample_rate(struct stk8312_data *data, u8 rate)
245 {
246         int ret;
247         u8 masked_reg;
248         u8 mode;
249         struct i2c_client *client = data->client;
250
251         if (rate == data->sample_rate_idx)
252                 return 0;
253
254         mode = data->mode;
255         /* We need to go in standby mode to modify registers */
256         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
257         if (ret < 0)
258                 return ret;
259
260         ret = i2c_smbus_read_byte_data(client, STK8312_REG_SR);
261         if (ret < 0)
262                 goto err_activate;
263
264         masked_reg = (ret & (~STK8312_SR_MASK)) | rate;
265
266         ret = i2c_smbus_write_byte_data(client, STK8312_REG_SR, masked_reg);
267         if (ret < 0)
268                 goto err_activate;
269
270         data->sample_rate_idx = rate;
271
272         return stk8312_set_mode(data, mode);
273
274 err_activate:
275         dev_err(&client->dev, "failed to set sampling rate\n");
276         stk8312_set_mode(data, mode);
277
278         return ret;
279 }
280
281 static int stk8312_set_range(struct stk8312_data *data, u8 range)
282 {
283         int ret;
284         u8 masked_reg;
285         u8 mode;
286         struct i2c_client *client = data->client;
287
288         if (range != 1 && range != 2)
289                 return -EINVAL;
290         else if (range == data->range)
291                 return 0;
292
293         mode = data->mode;
294         /* We need to go in standby mode to modify registers */
295         ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
296         if (ret < 0)
297                 return ret;
298
299         ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
300         if (ret < 0)
301                 goto err_activate;
302
303         masked_reg = ret & (~STK8312_RNG_MASK);
304         masked_reg |= range << STK8312_RNG_SHIFT;
305
306         ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
307         if (ret < 0)
308                 goto err_activate;
309
310         data->range = range;
311
312         return stk8312_set_mode(data, mode);
313
314 err_activate:
315         dev_err(&client->dev, "failed to change sensor range\n");
316         stk8312_set_mode(data, mode);
317
318         return ret;
319 }
320
321 static int stk8312_read_accel(struct stk8312_data *data, u8 address)
322 {
323         int ret;
324         struct i2c_client *client = data->client;
325
326         if (address > 2)
327                 return -EINVAL;
328
329         ret = i2c_smbus_read_byte_data(client, address);
330         if (ret < 0)
331                 dev_err(&client->dev, "register read failed\n");
332
333         return ret;
334 }
335
336 static int stk8312_read_raw(struct iio_dev *indio_dev,
337                             struct iio_chan_spec const *chan,
338                             int *val, int *val2, long mask)
339 {
340         struct stk8312_data *data = iio_priv(indio_dev);
341         int ret;
342
343         switch (mask) {
344         case IIO_CHAN_INFO_RAW:
345                 if (iio_buffer_enabled(indio_dev))
346                         return -EBUSY;
347                 mutex_lock(&data->lock);
348                 ret = stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
349                 if (ret < 0) {
350                         mutex_unlock(&data->lock);
351                         return ret;
352                 }
353                 ret = stk8312_read_accel(data, chan->address);
354                 if (ret < 0) {
355                         stk8312_set_mode(data,
356                                          data->mode & (~STK8312_MODE_ACTIVE));
357                         mutex_unlock(&data->lock);
358                         return ret;
359                 }
360                 *val = sign_extend32(ret, 7);
361                 ret = stk8312_set_mode(data,
362                                        data->mode & (~STK8312_MODE_ACTIVE));
363                 mutex_unlock(&data->lock);
364                 if (ret < 0)
365                         return ret;
366                 return IIO_VAL_INT;
367         case IIO_CHAN_INFO_SCALE:
368                 *val = stk8312_scale_table[data->range - 1][0];
369                 *val2 = stk8312_scale_table[data->range - 1][1];
370                 return IIO_VAL_INT_PLUS_MICRO;
371         case IIO_CHAN_INFO_SAMP_FREQ:
372                 *val = stk8312_samp_freq_table[data->sample_rate_idx].val;
373                 *val2 = stk8312_samp_freq_table[data->sample_rate_idx].val2;
374                 return IIO_VAL_INT_PLUS_MICRO;
375         }
376
377         return -EINVAL;
378 }
379
380 static int stk8312_write_raw(struct iio_dev *indio_dev,
381                              struct iio_chan_spec const *chan,
382                              int val, int val2, long mask)
383 {
384         int i;
385         int index = -1;
386         int ret;
387         struct stk8312_data *data = iio_priv(indio_dev);
388
389         switch (mask) {
390         case IIO_CHAN_INFO_SCALE:
391                 for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
392                         if (val == stk8312_scale_table[i][0] &&
393                             val2 == stk8312_scale_table[i][1]) {
394                                 index = i + 1;
395                                 break;
396                         }
397                 if (index < 0)
398                         return -EINVAL;
399
400                 mutex_lock(&data->lock);
401                 ret = stk8312_set_range(data, index);
402                 mutex_unlock(&data->lock);
403
404                 return ret;
405         case IIO_CHAN_INFO_SAMP_FREQ:
406                 for (i = 0; i < ARRAY_SIZE(stk8312_samp_freq_table); i++)
407                         if (val == stk8312_samp_freq_table[i].val &&
408                             val2 == stk8312_samp_freq_table[i].val2) {
409                                 index = i;
410                                 break;
411                         }
412                 if (index < 0)
413                         return -EINVAL;
414                 mutex_lock(&data->lock);
415                 ret = stk8312_set_sample_rate(data, index);
416                 mutex_unlock(&data->lock);
417
418                 return ret;
419         }
420
421         return -EINVAL;
422 }
423
424 static const struct iio_info stk8312_info = {
425         .driver_module          = THIS_MODULE,
426         .read_raw               = stk8312_read_raw,
427         .write_raw              = stk8312_write_raw,
428         .attrs                  = &stk8312_attribute_group,
429 };
430
431 static irqreturn_t stk8312_trigger_handler(int irq, void *p)
432 {
433         struct iio_poll_func *pf = p;
434         struct iio_dev *indio_dev = pf->indio_dev;
435         struct stk8312_data *data = iio_priv(indio_dev);
436         int bit, ret, i = 0;
437
438         mutex_lock(&data->lock);
439         /*
440          * Do a bulk read if all channels are requested,
441          * from 0x00 (XOUT) to 0x02 (ZOUT)
442          */
443         if (*(indio_dev->active_scan_mask) == STK8312_ALL_CHANNEL_MASK) {
444                 ret = i2c_smbus_read_i2c_block_data(data->client,
445                                                     STK8312_REG_XOUT,
446                                                     STK8312_ALL_CHANNEL_SIZE,
447                                                     data->buffer);
448                 if (ret < STK8312_ALL_CHANNEL_SIZE) {
449                         dev_err(&data->client->dev, "register read failed\n");
450                         mutex_unlock(&data->lock);
451                         goto err;
452                 }
453         } else {
454                 for_each_set_bit(bit, indio_dev->active_scan_mask,
455                                  indio_dev->masklength) {
456                         ret = stk8312_read_accel(data, bit);
457                         if (ret < 0) {
458                                 mutex_unlock(&data->lock);
459                                 goto err;
460                         }
461                         data->buffer[i++] = ret;
462                 }
463         }
464         mutex_unlock(&data->lock);
465
466         iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
467                                            pf->timestamp);
468 err:
469         iio_trigger_notify_done(indio_dev->trig);
470
471         return IRQ_HANDLED;
472 }
473
474 static irqreturn_t stk8312_data_rdy_trig_poll(int irq, void *private)
475 {
476         struct iio_dev *indio_dev = private;
477         struct stk8312_data *data = iio_priv(indio_dev);
478
479         if (data->dready_trigger_on)
480                 iio_trigger_poll(data->dready_trig);
481
482         return IRQ_HANDLED;
483 }
484
485 static int stk8312_buffer_preenable(struct iio_dev *indio_dev)
486 {
487         struct stk8312_data *data = iio_priv(indio_dev);
488
489         return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
490 }
491
492 static int stk8312_buffer_postdisable(struct iio_dev *indio_dev)
493 {
494         struct stk8312_data *data = iio_priv(indio_dev);
495
496         return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
497 }
498
499 static const struct iio_buffer_setup_ops stk8312_buffer_setup_ops = {
500         .preenable   = stk8312_buffer_preenable,
501         .postenable  = iio_triggered_buffer_postenable,
502         .predisable  = iio_triggered_buffer_predisable,
503         .postdisable = stk8312_buffer_postdisable,
504 };
505
506 static int stk8312_probe(struct i2c_client *client,
507                          const struct i2c_device_id *id)
508 {
509         int ret;
510         struct iio_dev *indio_dev;
511         struct stk8312_data *data;
512
513         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
514         if (!indio_dev) {
515                 dev_err(&client->dev, "iio allocation failed!\n");
516                 return -ENOMEM;
517         }
518
519         data = iio_priv(indio_dev);
520         data->client = client;
521         i2c_set_clientdata(client, indio_dev);
522         mutex_init(&data->lock);
523
524         indio_dev->dev.parent = &client->dev;
525         indio_dev->info = &stk8312_info;
526         indio_dev->name = STK8312_DRIVER_NAME;
527         indio_dev->modes = INDIO_DIRECT_MODE;
528         indio_dev->channels = stk8312_channels;
529         indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);
530
531         /* A software reset is recommended at power-on */
532         ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
533         if (ret < 0) {
534                 dev_err(&client->dev, "failed to reset sensor\n");
535                 return ret;
536         }
537         data->sample_rate_idx = STK8312_SR_400HZ_IDX;
538         ret = stk8312_set_range(data, STK8312_RNG_6G);
539         if (ret < 0)
540                 return ret;
541
542         ret = stk8312_set_mode(data,
543                                STK8312_MODE_INT_AH_PP | STK8312_MODE_ACTIVE);
544         if (ret < 0)
545                 return ret;
546
547         if (client->irq > 0) {
548                 ret = devm_request_threaded_irq(&client->dev, client->irq,
549                                                 stk8312_data_rdy_trig_poll,
550                                                 NULL,
551                                                 IRQF_TRIGGER_RISING |
552                                                 IRQF_ONESHOT,
553                                                 STK8312_IRQ_NAME,
554                                                 indio_dev);
555                 if (ret < 0) {
556                         dev_err(&client->dev, "request irq %d failed\n",
557                                 client->irq);
558                         goto err_power_off;
559                 }
560
561                 data->dready_trig = devm_iio_trigger_alloc(&client->dev,
562                                                            "%s-dev%d",
563                                                            indio_dev->name,
564                                                            indio_dev->id);
565                 if (!data->dready_trig) {
566                         ret = -ENOMEM;
567                         goto err_power_off;
568                 }
569
570                 data->dready_trig->dev.parent = &client->dev;
571                 data->dready_trig->ops = &stk8312_trigger_ops;
572                 iio_trigger_set_drvdata(data->dready_trig, indio_dev);
573                 ret = iio_trigger_register(data->dready_trig);
574                 if (ret) {
575                         dev_err(&client->dev, "iio trigger register failed\n");
576                         goto err_power_off;
577                 }
578         }
579
580         ret = iio_triggered_buffer_setup(indio_dev,
581                                          iio_pollfunc_store_time,
582                                          stk8312_trigger_handler,
583                                          &stk8312_buffer_setup_ops);
584         if (ret < 0) {
585                 dev_err(&client->dev, "iio triggered buffer setup failed\n");
586                 goto err_trigger_unregister;
587         }
588
589         ret = iio_device_register(indio_dev);
590         if (ret < 0) {
591                 dev_err(&client->dev, "device_register failed\n");
592                 goto err_buffer_cleanup;
593         }
594
595         return 0;
596
597 err_buffer_cleanup:
598         iio_triggered_buffer_cleanup(indio_dev);
599 err_trigger_unregister:
600         if (data->dready_trig)
601                 iio_trigger_unregister(data->dready_trig);
602 err_power_off:
603         stk8312_set_mode(data, STK8312_MODE_STANDBY);
604         return ret;
605 }
606
607 static int stk8312_remove(struct i2c_client *client)
608 {
609         struct iio_dev *indio_dev = i2c_get_clientdata(client);
610         struct stk8312_data *data = iio_priv(indio_dev);
611
612         iio_device_unregister(indio_dev);
613         iio_triggered_buffer_cleanup(indio_dev);
614
615         if (data->dready_trig)
616                 iio_trigger_unregister(data->dready_trig);
617
618         return stk8312_set_mode(data, STK8312_MODE_STANDBY);
619 }
620
621 #ifdef CONFIG_PM_SLEEP
622 static int stk8312_suspend(struct device *dev)
623 {
624         struct stk8312_data *data;
625
626         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
627
628         return stk8312_set_mode(data, data->mode & (~STK8312_MODE_ACTIVE));
629 }
630
631 static int stk8312_resume(struct device *dev)
632 {
633         struct stk8312_data *data;
634
635         data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
636
637         return stk8312_set_mode(data, data->mode | STK8312_MODE_ACTIVE);
638 }
639
640 static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
641
642 #define STK8312_PM_OPS (&stk8312_pm_ops)
643 #else
644 #define STK8312_PM_OPS NULL
645 #endif
646
647 static const struct i2c_device_id stk8312_i2c_id[] = {
648         {"STK8312", 0},
649         {}
650 };
651 MODULE_DEVICE_TABLE(i2c, stk8312_i2c_id);
652
653 static const struct acpi_device_id stk8312_acpi_id[] = {
654         {"STK8312", 0},
655         {}
656 };
657
658 MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
659
660 static struct i2c_driver stk8312_driver = {
661         .driver = {
662                 .name = STK8312_DRIVER_NAME,
663                 .pm = STK8312_PM_OPS,
664                 .acpi_match_table = ACPI_PTR(stk8312_acpi_id),
665         },
666         .probe =            stk8312_probe,
667         .remove =           stk8312_remove,
668         .id_table =         stk8312_i2c_id,
669 };
670
671 module_i2c_driver(stk8312_driver);
672
673 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
674 MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
675 MODULE_LICENSE("GPL v2");