xref: /linux/drivers/iio/proximity/sx9500.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
1 /*
2  * Copyright (c) 2014 Intel Corporation
3  *
4  * Driver for Semtech's SX9500 capacitive proximity/button solution.
5  * Datasheet available at
6  * <http://www.semtech.com/images/datasheet/sx9500.pdf>.
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License version 2 as published by
10  * the Free Software Foundation.
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include <linux/i2c.h>
17 #include <linux/irq.h>
18 #include <linux/acpi.h>
19 #include <linux/gpio/consumer.h>
20 #include <linux/regmap.h>
21 #include <linux/pm.h>
22 #include <linux/delay.h>
23 
24 #include <linux/iio/iio.h>
25 #include <linux/iio/buffer.h>
26 #include <linux/iio/sysfs.h>
27 #include <linux/iio/events.h>
28 #include <linux/iio/trigger.h>
29 #include <linux/iio/triggered_buffer.h>
30 #include <linux/iio/trigger_consumer.h>
31 
32 #define SX9500_DRIVER_NAME		"sx9500"
33 #define SX9500_IRQ_NAME			"sx9500_event"
34 
35 #define SX9500_GPIO_INT			"interrupt"
36 #define SX9500_GPIO_RESET		"reset"
37 
38 /* Register definitions. */
39 #define SX9500_REG_IRQ_SRC		0x00
40 #define SX9500_REG_STAT			0x01
41 #define SX9500_REG_IRQ_MSK		0x03
42 
43 #define SX9500_REG_PROX_CTRL0		0x06
44 #define SX9500_REG_PROX_CTRL1		0x07
45 #define SX9500_REG_PROX_CTRL2		0x08
46 #define SX9500_REG_PROX_CTRL3		0x09
47 #define SX9500_REG_PROX_CTRL4		0x0a
48 #define SX9500_REG_PROX_CTRL5		0x0b
49 #define SX9500_REG_PROX_CTRL6		0x0c
50 #define SX9500_REG_PROX_CTRL7		0x0d
51 #define SX9500_REG_PROX_CTRL8		0x0e
52 
53 #define SX9500_REG_SENSOR_SEL		0x20
54 #define SX9500_REG_USE_MSB		0x21
55 #define SX9500_REG_USE_LSB		0x22
56 #define SX9500_REG_AVG_MSB		0x23
57 #define SX9500_REG_AVG_LSB		0x24
58 #define SX9500_REG_DIFF_MSB		0x25
59 #define SX9500_REG_DIFF_LSB		0x26
60 #define SX9500_REG_OFFSET_MSB		0x27
61 #define SX9500_REG_OFFSET_LSB		0x28
62 
63 #define SX9500_REG_RESET		0x7f
64 
65 /* Write this to REG_RESET to do a soft reset. */
66 #define SX9500_SOFT_RESET		0xde
67 
68 #define SX9500_SCAN_PERIOD_MASK		GENMASK(6, 4)
69 #define SX9500_SCAN_PERIOD_SHIFT	4
70 
71 /*
72  * These serve for identifying IRQ source in the IRQ_SRC register, and
73  * also for masking the IRQs in the IRQ_MSK register.
74  */
75 #define SX9500_CLOSE_IRQ		BIT(6)
76 #define SX9500_FAR_IRQ			BIT(5)
77 #define SX9500_CONVDONE_IRQ		BIT(3)
78 
79 #define SX9500_PROXSTAT_SHIFT		4
80 #define SX9500_COMPSTAT_MASK		GENMASK(3, 0)
81 
82 #define SX9500_NUM_CHANNELS		4
83 #define SX9500_CHAN_MASK		GENMASK(SX9500_NUM_CHANNELS - 1, 0)
84 
85 struct sx9500_data {
86 	struct mutex mutex;
87 	struct i2c_client *client;
88 	struct iio_trigger *trig;
89 	struct regmap *regmap;
90 	struct gpio_desc *gpiod_rst;
91 	/*
92 	 * Last reading of the proximity status for each channel.  We
93 	 * only send an event to user space when this changes.
94 	 */
95 	bool prox_stat[SX9500_NUM_CHANNELS];
96 	bool event_enabled[SX9500_NUM_CHANNELS];
97 	bool trigger_enabled;
98 	u16 *buffer;
99 	/* Remember enabled channels and sample rate during suspend. */
100 	unsigned int suspend_ctrl0;
101 	struct completion completion;
102 	int data_rdy_users, close_far_users;
103 	int channel_users[SX9500_NUM_CHANNELS];
104 };
105 
106 static const struct iio_event_spec sx9500_events[] = {
107 	{
108 		.type = IIO_EV_TYPE_THRESH,
109 		.dir = IIO_EV_DIR_EITHER,
110 		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
111 	},
112 };
113 
114 #define SX9500_CHANNEL(idx)					\
115 	{							\
116 		.type = IIO_PROXIMITY,				\
117 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
118 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
119 		.indexed = 1,					\
120 		.channel = idx,					\
121 		.event_spec = sx9500_events,			\
122 		.num_event_specs = ARRAY_SIZE(sx9500_events),	\
123 		.scan_index = idx,				\
124 		.scan_type = {					\
125 			.sign = 'u',				\
126 			.realbits = 16,				\
127 			.storagebits = 16,			\
128 			.shift = 0,				\
129 		},						\
130 	}
131 
132 static const struct iio_chan_spec sx9500_channels[] = {
133 	SX9500_CHANNEL(0),
134 	SX9500_CHANNEL(1),
135 	SX9500_CHANNEL(2),
136 	SX9500_CHANNEL(3),
137 	IIO_CHAN_SOFT_TIMESTAMP(4),
138 };
139 
140 static const struct {
141 	int val;
142 	int val2;
143 } sx9500_samp_freq_table[] = {
144 	{33, 333333},
145 	{16, 666666},
146 	{11, 111111},
147 	{8, 333333},
148 	{6, 666666},
149 	{5, 0},
150 	{3, 333333},
151 	{2, 500000},
152 };
153 
154 static const unsigned int sx9500_scan_period_table[] = {
155 	30, 60, 90, 120, 150, 200, 300, 400,
156 };
157 
158 static const struct regmap_range sx9500_writable_reg_ranges[] = {
159 	regmap_reg_range(SX9500_REG_IRQ_MSK, SX9500_REG_IRQ_MSK),
160 	regmap_reg_range(SX9500_REG_PROX_CTRL0, SX9500_REG_PROX_CTRL8),
161 	regmap_reg_range(SX9500_REG_SENSOR_SEL, SX9500_REG_SENSOR_SEL),
162 	regmap_reg_range(SX9500_REG_OFFSET_MSB, SX9500_REG_OFFSET_LSB),
163 	regmap_reg_range(SX9500_REG_RESET, SX9500_REG_RESET),
164 };
165 
166 static const struct regmap_access_table sx9500_writeable_regs = {
167 	.yes_ranges = sx9500_writable_reg_ranges,
168 	.n_yes_ranges = ARRAY_SIZE(sx9500_writable_reg_ranges),
169 };
170 
171 /*
172  * All allocated registers are readable, so we just list unallocated
173  * ones.
174  */
175 static const struct regmap_range sx9500_non_readable_reg_ranges[] = {
176 	regmap_reg_range(SX9500_REG_STAT + 1, SX9500_REG_STAT + 1),
177 	regmap_reg_range(SX9500_REG_IRQ_MSK + 1, SX9500_REG_PROX_CTRL0 - 1),
178 	regmap_reg_range(SX9500_REG_PROX_CTRL8 + 1, SX9500_REG_SENSOR_SEL - 1),
179 	regmap_reg_range(SX9500_REG_OFFSET_LSB + 1, SX9500_REG_RESET - 1),
180 };
181 
182 static const struct regmap_access_table sx9500_readable_regs = {
183 	.no_ranges = sx9500_non_readable_reg_ranges,
184 	.n_no_ranges = ARRAY_SIZE(sx9500_non_readable_reg_ranges),
185 };
186 
187 static const struct regmap_range sx9500_volatile_reg_ranges[] = {
188 	regmap_reg_range(SX9500_REG_IRQ_SRC, SX9500_REG_STAT),
189 	regmap_reg_range(SX9500_REG_USE_MSB, SX9500_REG_OFFSET_LSB),
190 	regmap_reg_range(SX9500_REG_RESET, SX9500_REG_RESET),
191 };
192 
193 static const struct regmap_access_table sx9500_volatile_regs = {
194 	.yes_ranges = sx9500_volatile_reg_ranges,
195 	.n_yes_ranges = ARRAY_SIZE(sx9500_volatile_reg_ranges),
196 };
197 
198 static const struct regmap_config sx9500_regmap_config = {
199 	.reg_bits = 8,
200 	.val_bits = 8,
201 
202 	.max_register = SX9500_REG_RESET,
203 	.cache_type = REGCACHE_RBTREE,
204 
205 	.wr_table = &sx9500_writeable_regs,
206 	.rd_table = &sx9500_readable_regs,
207 	.volatile_table = &sx9500_volatile_regs,
208 };
209 
210 static int sx9500_inc_users(struct sx9500_data *data, int *counter,
211 			    unsigned int reg, unsigned int bitmask)
212 {
213 	(*counter)++;
214 	if (*counter != 1)
215 		/* Bit is already active, nothing to do. */
216 		return 0;
217 
218 	return regmap_update_bits(data->regmap, reg, bitmask, bitmask);
219 }
220 
221 static int sx9500_dec_users(struct sx9500_data *data, int *counter,
222 			    unsigned int reg, unsigned int bitmask)
223 {
224 	(*counter)--;
225 	if (*counter != 0)
226 		/* There are more users, do not deactivate. */
227 		return 0;
228 
229 	return regmap_update_bits(data->regmap, reg, bitmask, 0);
230 }
231 
232 static int sx9500_inc_chan_users(struct sx9500_data *data, int chan)
233 {
234 	return sx9500_inc_users(data, &data->channel_users[chan],
235 				SX9500_REG_PROX_CTRL0, BIT(chan));
236 }
237 
238 static int sx9500_dec_chan_users(struct sx9500_data *data, int chan)
239 {
240 	return sx9500_dec_users(data, &data->channel_users[chan],
241 				SX9500_REG_PROX_CTRL0, BIT(chan));
242 }
243 
244 static int sx9500_inc_data_rdy_users(struct sx9500_data *data)
245 {
246 	return sx9500_inc_users(data, &data->data_rdy_users,
247 				SX9500_REG_IRQ_MSK, SX9500_CONVDONE_IRQ);
248 }
249 
250 static int sx9500_dec_data_rdy_users(struct sx9500_data *data)
251 {
252 	return sx9500_dec_users(data, &data->data_rdy_users,
253 				SX9500_REG_IRQ_MSK, SX9500_CONVDONE_IRQ);
254 }
255 
256 static int sx9500_inc_close_far_users(struct sx9500_data *data)
257 {
258 	return sx9500_inc_users(data, &data->close_far_users,
259 				SX9500_REG_IRQ_MSK,
260 				SX9500_CLOSE_IRQ | SX9500_FAR_IRQ);
261 }
262 
263 static int sx9500_dec_close_far_users(struct sx9500_data *data)
264 {
265 	return sx9500_dec_users(data, &data->close_far_users,
266 				SX9500_REG_IRQ_MSK,
267 				SX9500_CLOSE_IRQ | SX9500_FAR_IRQ);
268 }
269 
270 static int sx9500_read_prox_data(struct sx9500_data *data,
271 				 const struct iio_chan_spec *chan,
272 				 int *val)
273 {
274 	int ret;
275 	__be16 regval;
276 
277 	ret = regmap_write(data->regmap, SX9500_REG_SENSOR_SEL, chan->channel);
278 	if (ret < 0)
279 		return ret;
280 
281 	ret = regmap_bulk_read(data->regmap, SX9500_REG_USE_MSB, &regval, 2);
282 	if (ret < 0)
283 		return ret;
284 
285 	*val = be16_to_cpu(regval);
286 
287 	return IIO_VAL_INT;
288 }
289 
290 /*
291  * If we have no interrupt support, we have to wait for a scan period
292  * after enabling a channel to get a result.
293  */
294 static int sx9500_wait_for_sample(struct sx9500_data *data)
295 {
296 	int ret;
297 	unsigned int val;
298 
299 	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0, &val);
300 	if (ret < 0)
301 		return ret;
302 
303 	val = (val & SX9500_SCAN_PERIOD_MASK) >> SX9500_SCAN_PERIOD_SHIFT;
304 
305 	msleep(sx9500_scan_period_table[val]);
306 
307 	return 0;
308 }
309 
310 static int sx9500_read_proximity(struct sx9500_data *data,
311 				 const struct iio_chan_spec *chan,
312 				 int *val)
313 {
314 	int ret;
315 
316 	mutex_lock(&data->mutex);
317 
318 	ret = sx9500_inc_chan_users(data, chan->channel);
319 	if (ret < 0)
320 		goto out;
321 
322 	ret = sx9500_inc_data_rdy_users(data);
323 	if (ret < 0)
324 		goto out_dec_chan;
325 
326 	mutex_unlock(&data->mutex);
327 
328 	if (data->client->irq > 0)
329 		ret = wait_for_completion_interruptible(&data->completion);
330 	else
331 		ret = sx9500_wait_for_sample(data);
332 
333 	mutex_lock(&data->mutex);
334 
335 	if (ret < 0)
336 		goto out_dec_data_rdy;
337 
338 	ret = sx9500_read_prox_data(data, chan, val);
339 	if (ret < 0)
340 		goto out_dec_data_rdy;
341 
342 	ret = sx9500_dec_data_rdy_users(data);
343 	if (ret < 0)
344 		goto out_dec_chan;
345 
346 	ret = sx9500_dec_chan_users(data, chan->channel);
347 	if (ret < 0)
348 		goto out;
349 
350 	ret = IIO_VAL_INT;
351 
352 	goto out;
353 
354 out_dec_data_rdy:
355 	sx9500_dec_data_rdy_users(data);
356 out_dec_chan:
357 	sx9500_dec_chan_users(data, chan->channel);
358 out:
359 	mutex_unlock(&data->mutex);
360 	reinit_completion(&data->completion);
361 
362 	return ret;
363 }
364 
365 static int sx9500_read_samp_freq(struct sx9500_data *data,
366 				 int *val, int *val2)
367 {
368 	int ret;
369 	unsigned int regval;
370 
371 	mutex_lock(&data->mutex);
372 	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0, &regval);
373 	mutex_unlock(&data->mutex);
374 
375 	if (ret < 0)
376 		return ret;
377 
378 	regval = (regval & SX9500_SCAN_PERIOD_MASK) >> SX9500_SCAN_PERIOD_SHIFT;
379 	*val = sx9500_samp_freq_table[regval].val;
380 	*val2 = sx9500_samp_freq_table[regval].val2;
381 
382 	return IIO_VAL_INT_PLUS_MICRO;
383 }
384 
385 static int sx9500_read_raw(struct iio_dev *indio_dev,
386 			   const struct iio_chan_spec *chan,
387 			   int *val, int *val2, long mask)
388 {
389 	struct sx9500_data *data = iio_priv(indio_dev);
390 
391 	switch (chan->type) {
392 	case IIO_PROXIMITY:
393 		switch (mask) {
394 		case IIO_CHAN_INFO_RAW:
395 			if (iio_buffer_enabled(indio_dev))
396 				return -EBUSY;
397 			return sx9500_read_proximity(data, chan, val);
398 		case IIO_CHAN_INFO_SAMP_FREQ:
399 			return sx9500_read_samp_freq(data, val, val2);
400 		default:
401 			return -EINVAL;
402 		}
403 	default:
404 		return -EINVAL;
405 	}
406 }
407 
408 static int sx9500_set_samp_freq(struct sx9500_data *data,
409 				int val, int val2)
410 {
411 	int i, ret;
412 
413 	for (i = 0; i < ARRAY_SIZE(sx9500_samp_freq_table); i++)
414 		if (val == sx9500_samp_freq_table[i].val &&
415 		    val2 == sx9500_samp_freq_table[i].val2)
416 			break;
417 
418 	if (i == ARRAY_SIZE(sx9500_samp_freq_table))
419 		return -EINVAL;
420 
421 	mutex_lock(&data->mutex);
422 
423 	ret = regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
424 				 SX9500_SCAN_PERIOD_MASK,
425 				 i << SX9500_SCAN_PERIOD_SHIFT);
426 
427 	mutex_unlock(&data->mutex);
428 
429 	return ret;
430 }
431 
432 static int sx9500_write_raw(struct iio_dev *indio_dev,
433 			    const struct iio_chan_spec *chan,
434 			    int val, int val2, long mask)
435 {
436 	struct sx9500_data *data = iio_priv(indio_dev);
437 
438 	switch (chan->type) {
439 	case IIO_PROXIMITY:
440 		switch (mask) {
441 		case IIO_CHAN_INFO_SAMP_FREQ:
442 			return sx9500_set_samp_freq(data, val, val2);
443 		default:
444 			return -EINVAL;
445 		}
446 	default:
447 		return -EINVAL;
448 	}
449 }
450 
451 static irqreturn_t sx9500_irq_handler(int irq, void *private)
452 {
453 	struct iio_dev *indio_dev = private;
454 	struct sx9500_data *data = iio_priv(indio_dev);
455 
456 	if (data->trigger_enabled)
457 		iio_trigger_poll(data->trig);
458 
459 	/*
460 	 * Even if no event is enabled, we need to wake the thread to
461 	 * clear the interrupt state by reading SX9500_REG_IRQ_SRC.  It
462 	 * is not possible to do that here because regmap_read takes a
463 	 * mutex.
464 	 */
465 	return IRQ_WAKE_THREAD;
466 }
467 
468 static void sx9500_push_events(struct iio_dev *indio_dev)
469 {
470 	int ret;
471 	unsigned int val, chan;
472 	struct sx9500_data *data = iio_priv(indio_dev);
473 
474 	ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
475 	if (ret < 0) {
476 		dev_err(&data->client->dev, "i2c transfer error in irq\n");
477 		return;
478 	}
479 
480 	val >>= SX9500_PROXSTAT_SHIFT;
481 	for (chan = 0; chan < SX9500_NUM_CHANNELS; chan++) {
482 		int dir;
483 		u64 ev;
484 		bool new_prox = val & BIT(chan);
485 
486 		if (!data->event_enabled[chan])
487 			continue;
488 		if (new_prox == data->prox_stat[chan])
489 			/* No change on this channel. */
490 			continue;
491 
492 		dir = new_prox ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
493 		ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan,
494 					  IIO_EV_TYPE_THRESH, dir);
495 		iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev));
496 		data->prox_stat[chan] = new_prox;
497 	}
498 }
499 
500 static irqreturn_t sx9500_irq_thread_handler(int irq, void *private)
501 {
502 	struct iio_dev *indio_dev = private;
503 	struct sx9500_data *data = iio_priv(indio_dev);
504 	int ret;
505 	unsigned int val;
506 
507 	mutex_lock(&data->mutex);
508 
509 	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
510 	if (ret < 0) {
511 		dev_err(&data->client->dev, "i2c transfer error in irq\n");
512 		goto out;
513 	}
514 
515 	if (val & (SX9500_CLOSE_IRQ | SX9500_FAR_IRQ))
516 		sx9500_push_events(indio_dev);
517 
518 	if (val & SX9500_CONVDONE_IRQ)
519 		complete_all(&data->completion);
520 
521 out:
522 	mutex_unlock(&data->mutex);
523 
524 	return IRQ_HANDLED;
525 }
526 
527 static int sx9500_read_event_config(struct iio_dev *indio_dev,
528 				    const struct iio_chan_spec *chan,
529 				    enum iio_event_type type,
530 				    enum iio_event_direction dir)
531 {
532 	struct sx9500_data *data = iio_priv(indio_dev);
533 
534 	if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
535 	    dir != IIO_EV_DIR_EITHER)
536 		return -EINVAL;
537 
538 	return data->event_enabled[chan->channel];
539 }
540 
541 static int sx9500_write_event_config(struct iio_dev *indio_dev,
542 				     const struct iio_chan_spec *chan,
543 				     enum iio_event_type type,
544 				     enum iio_event_direction dir,
545 				     int state)
546 {
547 	struct sx9500_data *data = iio_priv(indio_dev);
548 	int ret;
549 
550 	if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
551 	    dir != IIO_EV_DIR_EITHER)
552 		return -EINVAL;
553 
554 	mutex_lock(&data->mutex);
555 
556 	if (state == 1) {
557 		ret = sx9500_inc_chan_users(data, chan->channel);
558 		if (ret < 0)
559 			goto out_unlock;
560 		ret = sx9500_inc_close_far_users(data);
561 		if (ret < 0)
562 			goto out_undo_chan;
563 	} else {
564 		ret = sx9500_dec_chan_users(data, chan->channel);
565 		if (ret < 0)
566 			goto out_unlock;
567 		ret = sx9500_dec_close_far_users(data);
568 		if (ret < 0)
569 			goto out_undo_chan;
570 	}
571 
572 	data->event_enabled[chan->channel] = state;
573 	goto out_unlock;
574 
575 out_undo_chan:
576 	if (state == 1)
577 		sx9500_dec_chan_users(data, chan->channel);
578 	else
579 		sx9500_inc_chan_users(data, chan->channel);
580 out_unlock:
581 	mutex_unlock(&data->mutex);
582 	return ret;
583 }
584 
585 static int sx9500_update_scan_mode(struct iio_dev *indio_dev,
586 				   const unsigned long *scan_mask)
587 {
588 	struct sx9500_data *data = iio_priv(indio_dev);
589 
590 	mutex_lock(&data->mutex);
591 	kfree(data->buffer);
592 	data->buffer = kzalloc(indio_dev->scan_bytes, GFP_KERNEL);
593 	mutex_unlock(&data->mutex);
594 
595 	if (data->buffer == NULL)
596 		return -ENOMEM;
597 
598 	return 0;
599 }
600 
601 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
602 	"2.500000 3.333333 5 6.666666 8.333333 11.111111 16.666666 33.333333");
603 
604 static struct attribute *sx9500_attributes[] = {
605 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
606 	NULL,
607 };
608 
609 static const struct attribute_group sx9500_attribute_group = {
610 	.attrs = sx9500_attributes,
611 };
612 
613 static const struct iio_info sx9500_info = {
614 	.driver_module = THIS_MODULE,
615 	.attrs = &sx9500_attribute_group,
616 	.read_raw = &sx9500_read_raw,
617 	.write_raw = &sx9500_write_raw,
618 	.read_event_config = &sx9500_read_event_config,
619 	.write_event_config = &sx9500_write_event_config,
620 	.update_scan_mode = &sx9500_update_scan_mode,
621 };
622 
623 static int sx9500_set_trigger_state(struct iio_trigger *trig,
624 				    bool state)
625 {
626 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
627 	struct sx9500_data *data = iio_priv(indio_dev);
628 	int ret;
629 
630 	mutex_lock(&data->mutex);
631 
632 	if (state)
633 		ret = sx9500_inc_data_rdy_users(data);
634 	else
635 		ret = sx9500_dec_data_rdy_users(data);
636 	if (ret < 0)
637 		goto out;
638 
639 	data->trigger_enabled = state;
640 
641 out:
642 	mutex_unlock(&data->mutex);
643 
644 	return ret;
645 }
646 
647 static const struct iio_trigger_ops sx9500_trigger_ops = {
648 	.set_trigger_state = sx9500_set_trigger_state,
649 	.owner = THIS_MODULE,
650 };
651 
652 static irqreturn_t sx9500_trigger_handler(int irq, void *private)
653 {
654 	struct iio_poll_func *pf = private;
655 	struct iio_dev *indio_dev = pf->indio_dev;
656 	struct sx9500_data *data = iio_priv(indio_dev);
657 	int val, bit, ret, i = 0;
658 
659 	mutex_lock(&data->mutex);
660 
661 	for_each_set_bit(bit, indio_dev->active_scan_mask,
662 			 indio_dev->masklength) {
663 		ret = sx9500_read_prox_data(data, &indio_dev->channels[bit],
664 					    &val);
665 		if (ret < 0)
666 			goto out;
667 
668 		data->buffer[i++] = val;
669 	}
670 
671 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
672 					   iio_get_time_ns(indio_dev));
673 
674 out:
675 	mutex_unlock(&data->mutex);
676 
677 	iio_trigger_notify_done(indio_dev->trig);
678 
679 	return IRQ_HANDLED;
680 }
681 
682 static int sx9500_buffer_preenable(struct iio_dev *indio_dev)
683 {
684 	struct sx9500_data *data = iio_priv(indio_dev);
685 	int ret = 0, i;
686 
687 	mutex_lock(&data->mutex);
688 
689 	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
690 		if (test_bit(i, indio_dev->active_scan_mask)) {
691 			ret = sx9500_inc_chan_users(data, i);
692 			if (ret)
693 				break;
694 		}
695 
696 	if (ret)
697 		for (i = i - 1; i >= 0; i--)
698 			if (test_bit(i, indio_dev->active_scan_mask))
699 				sx9500_dec_chan_users(data, i);
700 
701 	mutex_unlock(&data->mutex);
702 
703 	return ret;
704 }
705 
706 static int sx9500_buffer_predisable(struct iio_dev *indio_dev)
707 {
708 	struct sx9500_data *data = iio_priv(indio_dev);
709 	int ret = 0, i;
710 
711 	iio_triggered_buffer_predisable(indio_dev);
712 
713 	mutex_lock(&data->mutex);
714 
715 	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
716 		if (test_bit(i, indio_dev->active_scan_mask)) {
717 			ret = sx9500_dec_chan_users(data, i);
718 			if (ret)
719 				break;
720 		}
721 
722 	if (ret)
723 		for (i = i - 1; i >= 0; i--)
724 			if (test_bit(i, indio_dev->active_scan_mask))
725 				sx9500_inc_chan_users(data, i);
726 
727 	mutex_unlock(&data->mutex);
728 
729 	return ret;
730 }
731 
732 static const struct iio_buffer_setup_ops sx9500_buffer_setup_ops = {
733 	.preenable = sx9500_buffer_preenable,
734 	.postenable = iio_triggered_buffer_postenable,
735 	.predisable = sx9500_buffer_predisable,
736 };
737 
738 struct sx9500_reg_default {
739 	u8 reg;
740 	u8 def;
741 };
742 
743 static const struct sx9500_reg_default sx9500_default_regs[] = {
744 	{
745 		.reg = SX9500_REG_PROX_CTRL1,
746 		/* Shield enabled, small range. */
747 		.def = 0x43,
748 	},
749 	{
750 		.reg = SX9500_REG_PROX_CTRL2,
751 		/* x8 gain, 167kHz frequency, finest resolution. */
752 		.def = 0x77,
753 	},
754 	{
755 		.reg = SX9500_REG_PROX_CTRL3,
756 		/* Doze enabled, 2x scan period doze, no raw filter. */
757 		.def = 0x40,
758 	},
759 	{
760 		.reg = SX9500_REG_PROX_CTRL4,
761 		/* Average threshold. */
762 		.def = 0x30,
763 	},
764 	{
765 		.reg = SX9500_REG_PROX_CTRL5,
766 		/*
767 		 * Debouncer off, lowest average negative filter,
768 		 * highest average postive filter.
769 		 */
770 		.def = 0x0f,
771 	},
772 	{
773 		.reg = SX9500_REG_PROX_CTRL6,
774 		/* Proximity detection threshold: 280 */
775 		.def = 0x0e,
776 	},
777 	{
778 		.reg = SX9500_REG_PROX_CTRL7,
779 		/*
780 		 * No automatic compensation, compensate each pin
781 		 * independently, proximity hysteresis: 32, close
782 		 * debouncer off, far debouncer off.
783 		 */
784 		.def = 0x00,
785 	},
786 	{
787 		.reg = SX9500_REG_PROX_CTRL8,
788 		/* No stuck timeout, no periodic compensation. */
789 		.def = 0x00,
790 	},
791 	{
792 		.reg = SX9500_REG_PROX_CTRL0,
793 		/* Scan period: 30ms, all sensors disabled. */
794 		.def = 0x00,
795 	},
796 };
797 
798 /* Activate all channels and perform an initial compensation. */
799 static int sx9500_init_compensation(struct iio_dev *indio_dev)
800 {
801 	struct sx9500_data *data = iio_priv(indio_dev);
802 	int i, ret;
803 	unsigned int val;
804 
805 	ret = regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
806 				 SX9500_CHAN_MASK, SX9500_CHAN_MASK);
807 	if (ret < 0)
808 		return ret;
809 
810 	for (i = 10; i >= 0; i--) {
811 		usleep_range(10000, 20000);
812 		ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
813 		if (ret < 0)
814 			goto out;
815 		if (!(val & SX9500_COMPSTAT_MASK))
816 			break;
817 	}
818 
819 	if (i < 0) {
820 		dev_err(&data->client->dev, "initial compensation timed out");
821 		ret = -ETIMEDOUT;
822 	}
823 
824 out:
825 	regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
826 			   SX9500_CHAN_MASK, 0);
827 	return ret;
828 }
829 
830 static int sx9500_init_device(struct iio_dev *indio_dev)
831 {
832 	struct sx9500_data *data = iio_priv(indio_dev);
833 	int ret, i;
834 	unsigned int val;
835 
836 	if (data->gpiod_rst) {
837 		gpiod_set_value_cansleep(data->gpiod_rst, 0);
838 		usleep_range(1000, 2000);
839 		gpiod_set_value_cansleep(data->gpiod_rst, 1);
840 		usleep_range(1000, 2000);
841 	}
842 
843 	ret = regmap_write(data->regmap, SX9500_REG_IRQ_MSK, 0);
844 	if (ret < 0)
845 		return ret;
846 
847 	ret = regmap_write(data->regmap, SX9500_REG_RESET,
848 			   SX9500_SOFT_RESET);
849 	if (ret < 0)
850 		return ret;
851 
852 	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
853 	if (ret < 0)
854 		return ret;
855 
856 	for (i = 0; i < ARRAY_SIZE(sx9500_default_regs); i++) {
857 		ret = regmap_write(data->regmap,
858 				   sx9500_default_regs[i].reg,
859 				   sx9500_default_regs[i].def);
860 		if (ret < 0)
861 			return ret;
862 	}
863 
864 	return sx9500_init_compensation(indio_dev);
865 }
866 
867 static void sx9500_gpio_probe(struct i2c_client *client,
868 			      struct sx9500_data *data)
869 {
870 	struct device *dev;
871 
872 	if (!client)
873 		return;
874 
875 	dev = &client->dev;
876 
877 	data->gpiod_rst = devm_gpiod_get_index(dev, SX9500_GPIO_RESET,
878 					       0, GPIOD_OUT_HIGH);
879 	if (IS_ERR(data->gpiod_rst)) {
880 		dev_warn(dev, "gpio get reset pin failed\n");
881 		data->gpiod_rst = NULL;
882 	}
883 }
884 
885 static int sx9500_probe(struct i2c_client *client,
886 			const struct i2c_device_id *id)
887 {
888 	int ret;
889 	struct iio_dev *indio_dev;
890 	struct sx9500_data *data;
891 
892 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
893 	if (indio_dev == NULL)
894 		return -ENOMEM;
895 
896 	data = iio_priv(indio_dev);
897 	data->client = client;
898 	mutex_init(&data->mutex);
899 	init_completion(&data->completion);
900 	data->trigger_enabled = false;
901 
902 	data->regmap = devm_regmap_init_i2c(client, &sx9500_regmap_config);
903 	if (IS_ERR(data->regmap))
904 		return PTR_ERR(data->regmap);
905 
906 	indio_dev->dev.parent = &client->dev;
907 	indio_dev->name = SX9500_DRIVER_NAME;
908 	indio_dev->channels = sx9500_channels;
909 	indio_dev->num_channels = ARRAY_SIZE(sx9500_channels);
910 	indio_dev->info = &sx9500_info;
911 	indio_dev->modes = INDIO_DIRECT_MODE;
912 	i2c_set_clientdata(client, indio_dev);
913 
914 	sx9500_gpio_probe(client, data);
915 
916 	ret = sx9500_init_device(indio_dev);
917 	if (ret < 0)
918 		return ret;
919 
920 	if (client->irq <= 0)
921 		dev_warn(&client->dev, "no valid irq found\n");
922 	else {
923 		ret = devm_request_threaded_irq(&client->dev, client->irq,
924 				sx9500_irq_handler, sx9500_irq_thread_handler,
925 				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
926 				SX9500_IRQ_NAME, indio_dev);
927 		if (ret < 0)
928 			return ret;
929 
930 		data->trig = devm_iio_trigger_alloc(&client->dev,
931 				"%s-dev%d", indio_dev->name, indio_dev->id);
932 		if (!data->trig)
933 			return -ENOMEM;
934 
935 		data->trig->dev.parent = &client->dev;
936 		data->trig->ops = &sx9500_trigger_ops;
937 		iio_trigger_set_drvdata(data->trig, indio_dev);
938 
939 		ret = iio_trigger_register(data->trig);
940 		if (ret)
941 			return ret;
942 	}
943 
944 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
945 					 sx9500_trigger_handler,
946 					 &sx9500_buffer_setup_ops);
947 	if (ret < 0)
948 		goto out_trigger_unregister;
949 
950 	ret = iio_device_register(indio_dev);
951 	if (ret < 0)
952 		goto out_buffer_cleanup;
953 
954 	return 0;
955 
956 out_buffer_cleanup:
957 	iio_triggered_buffer_cleanup(indio_dev);
958 out_trigger_unregister:
959 	if (client->irq > 0)
960 		iio_trigger_unregister(data->trig);
961 
962 	return ret;
963 }
964 
965 static int sx9500_remove(struct i2c_client *client)
966 {
967 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
968 	struct sx9500_data *data = iio_priv(indio_dev);
969 
970 	iio_device_unregister(indio_dev);
971 	iio_triggered_buffer_cleanup(indio_dev);
972 	if (client->irq > 0)
973 		iio_trigger_unregister(data->trig);
974 	kfree(data->buffer);
975 
976 	return 0;
977 }
978 
979 #ifdef CONFIG_PM_SLEEP
980 static int sx9500_suspend(struct device *dev)
981 {
982 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
983 	struct sx9500_data *data = iio_priv(indio_dev);
984 	int ret;
985 
986 	mutex_lock(&data->mutex);
987 	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0,
988 			  &data->suspend_ctrl0);
989 	if (ret < 0)
990 		goto out;
991 
992 	/*
993 	 * Scan period doesn't matter because when all the sensors are
994 	 * deactivated the device is in sleep mode.
995 	 */
996 	ret = regmap_write(data->regmap, SX9500_REG_PROX_CTRL0, 0);
997 
998 out:
999 	mutex_unlock(&data->mutex);
1000 	return ret;
1001 }
1002 
1003 static int sx9500_resume(struct device *dev)
1004 {
1005 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
1006 	struct sx9500_data *data = iio_priv(indio_dev);
1007 	int ret;
1008 
1009 	mutex_lock(&data->mutex);
1010 	ret = regmap_write(data->regmap, SX9500_REG_PROX_CTRL0,
1011 			   data->suspend_ctrl0);
1012 	mutex_unlock(&data->mutex);
1013 
1014 	return ret;
1015 }
1016 #endif /* CONFIG_PM_SLEEP */
1017 
1018 static const struct dev_pm_ops sx9500_pm_ops = {
1019 	SET_SYSTEM_SLEEP_PM_OPS(sx9500_suspend, sx9500_resume)
1020 };
1021 
1022 static const struct acpi_device_id sx9500_acpi_match[] = {
1023 	{"SSX9500", 0},
1024 	{ },
1025 };
1026 MODULE_DEVICE_TABLE(acpi, sx9500_acpi_match);
1027 
1028 static const struct i2c_device_id sx9500_id[] = {
1029 	{"sx9500", 0},
1030 	{ },
1031 };
1032 MODULE_DEVICE_TABLE(i2c, sx9500_id);
1033 
1034 static struct i2c_driver sx9500_driver = {
1035 	.driver = {
1036 		.name	= SX9500_DRIVER_NAME,
1037 		.acpi_match_table = ACPI_PTR(sx9500_acpi_match),
1038 		.pm = &sx9500_pm_ops,
1039 	},
1040 	.probe		= sx9500_probe,
1041 	.remove		= sx9500_remove,
1042 	.id_table	= sx9500_id,
1043 };
1044 module_i2c_driver(sx9500_driver);
1045 
1046 MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
1047 MODULE_DESCRIPTION("Driver for Semtech SX9500 proximity sensor");
1048 MODULE_LICENSE("GPL v2");
1049