1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2014 Intel Corporation
4  *
5  * Driver for Semtech's SX9500 capacitive proximity/button solution.
6  * Datasheet available at
7  * <http://www.semtech.com/images/datasheet/sx9500.pdf>.
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/module.h>
13 #include <linux/i2c.h>
14 #include <linux/irq.h>
15 #include <linux/acpi.h>
16 #include <linux/gpio/consumer.h>
17 #include <linux/regmap.h>
18 #include <linux/pm.h>
19 #include <linux/delay.h>
20 
21 #include <linux/iio/iio.h>
22 #include <linux/iio/buffer.h>
23 #include <linux/iio/sysfs.h>
24 #include <linux/iio/events.h>
25 #include <linux/iio/trigger.h>
26 #include <linux/iio/triggered_buffer.h>
27 #include <linux/iio/trigger_consumer.h>
28 
29 #define SX9500_DRIVER_NAME		"sx9500"
30 #define SX9500_IRQ_NAME			"sx9500_event"
31 
32 /* Register definitions. */
33 #define SX9500_REG_IRQ_SRC		0x00
34 #define SX9500_REG_STAT			0x01
35 #define SX9500_REG_IRQ_MSK		0x03
36 
37 #define SX9500_REG_PROX_CTRL0		0x06
38 #define SX9500_REG_PROX_CTRL1		0x07
39 #define SX9500_REG_PROX_CTRL2		0x08
40 #define SX9500_REG_PROX_CTRL3		0x09
41 #define SX9500_REG_PROX_CTRL4		0x0a
42 #define SX9500_REG_PROX_CTRL5		0x0b
43 #define SX9500_REG_PROX_CTRL6		0x0c
44 #define SX9500_REG_PROX_CTRL7		0x0d
45 #define SX9500_REG_PROX_CTRL8		0x0e
46 
47 #define SX9500_REG_SENSOR_SEL		0x20
48 #define SX9500_REG_USE_MSB		0x21
49 #define SX9500_REG_USE_LSB		0x22
50 #define SX9500_REG_AVG_MSB		0x23
51 #define SX9500_REG_AVG_LSB		0x24
52 #define SX9500_REG_DIFF_MSB		0x25
53 #define SX9500_REG_DIFF_LSB		0x26
54 #define SX9500_REG_OFFSET_MSB		0x27
55 #define SX9500_REG_OFFSET_LSB		0x28
56 
57 #define SX9500_REG_RESET		0x7f
58 
59 /* Write this to REG_RESET to do a soft reset. */
60 #define SX9500_SOFT_RESET		0xde
61 
62 #define SX9500_SCAN_PERIOD_MASK		GENMASK(6, 4)
63 #define SX9500_SCAN_PERIOD_SHIFT	4
64 
65 /*
66  * These serve for identifying IRQ source in the IRQ_SRC register, and
67  * also for masking the IRQs in the IRQ_MSK register.
68  */
69 #define SX9500_CLOSE_IRQ		BIT(6)
70 #define SX9500_FAR_IRQ			BIT(5)
71 #define SX9500_CONVDONE_IRQ		BIT(3)
72 
73 #define SX9500_PROXSTAT_SHIFT		4
74 #define SX9500_COMPSTAT_MASK		GENMASK(3, 0)
75 
76 #define SX9500_NUM_CHANNELS		4
77 #define SX9500_CHAN_MASK		GENMASK(SX9500_NUM_CHANNELS - 1, 0)
78 
79 struct sx9500_data {
80 	struct mutex mutex;
81 	struct i2c_client *client;
82 	struct iio_trigger *trig;
83 	struct regmap *regmap;
84 	struct gpio_desc *gpiod_rst;
85 	/*
86 	 * Last reading of the proximity status for each channel.  We
87 	 * only send an event to user space when this changes.
88 	 */
89 	bool prox_stat[SX9500_NUM_CHANNELS];
90 	bool event_enabled[SX9500_NUM_CHANNELS];
91 	bool trigger_enabled;
92 	u16 *buffer;
93 	/* Remember enabled channels and sample rate during suspend. */
94 	unsigned int suspend_ctrl0;
95 	struct completion completion;
96 	int data_rdy_users, close_far_users;
97 	int channel_users[SX9500_NUM_CHANNELS];
98 };
99 
100 static const struct iio_event_spec sx9500_events[] = {
101 	{
102 		.type = IIO_EV_TYPE_THRESH,
103 		.dir = IIO_EV_DIR_EITHER,
104 		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
105 	},
106 };
107 
108 #define SX9500_CHANNEL(idx)					\
109 	{							\
110 		.type = IIO_PROXIMITY,				\
111 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
112 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
113 		.indexed = 1,					\
114 		.channel = idx,					\
115 		.event_spec = sx9500_events,			\
116 		.num_event_specs = ARRAY_SIZE(sx9500_events),	\
117 		.scan_index = idx,				\
118 		.scan_type = {					\
119 			.sign = 'u',				\
120 			.realbits = 16,				\
121 			.storagebits = 16,			\
122 			.shift = 0,				\
123 		},						\
124 	}
125 
126 static const struct iio_chan_spec sx9500_channels[] = {
127 	SX9500_CHANNEL(0),
128 	SX9500_CHANNEL(1),
129 	SX9500_CHANNEL(2),
130 	SX9500_CHANNEL(3),
131 	IIO_CHAN_SOFT_TIMESTAMP(4),
132 };
133 
134 static const struct {
135 	int val;
136 	int val2;
137 } sx9500_samp_freq_table[] = {
138 	{33, 333333},
139 	{16, 666666},
140 	{11, 111111},
141 	{8, 333333},
142 	{6, 666666},
143 	{5, 0},
144 	{3, 333333},
145 	{2, 500000},
146 };
147 
148 static const unsigned int sx9500_scan_period_table[] = {
149 	30, 60, 90, 120, 150, 200, 300, 400,
150 };
151 
152 static const struct regmap_range sx9500_writable_reg_ranges[] = {
153 	regmap_reg_range(SX9500_REG_IRQ_MSK, SX9500_REG_IRQ_MSK),
154 	regmap_reg_range(SX9500_REG_PROX_CTRL0, SX9500_REG_PROX_CTRL8),
155 	regmap_reg_range(SX9500_REG_SENSOR_SEL, SX9500_REG_SENSOR_SEL),
156 	regmap_reg_range(SX9500_REG_OFFSET_MSB, SX9500_REG_OFFSET_LSB),
157 	regmap_reg_range(SX9500_REG_RESET, SX9500_REG_RESET),
158 };
159 
160 static const struct regmap_access_table sx9500_writeable_regs = {
161 	.yes_ranges = sx9500_writable_reg_ranges,
162 	.n_yes_ranges = ARRAY_SIZE(sx9500_writable_reg_ranges),
163 };
164 
165 /*
166  * All allocated registers are readable, so we just list unallocated
167  * ones.
168  */
169 static const struct regmap_range sx9500_non_readable_reg_ranges[] = {
170 	regmap_reg_range(SX9500_REG_STAT + 1, SX9500_REG_STAT + 1),
171 	regmap_reg_range(SX9500_REG_IRQ_MSK + 1, SX9500_REG_PROX_CTRL0 - 1),
172 	regmap_reg_range(SX9500_REG_PROX_CTRL8 + 1, SX9500_REG_SENSOR_SEL - 1),
173 	regmap_reg_range(SX9500_REG_OFFSET_LSB + 1, SX9500_REG_RESET - 1),
174 };
175 
176 static const struct regmap_access_table sx9500_readable_regs = {
177 	.no_ranges = sx9500_non_readable_reg_ranges,
178 	.n_no_ranges = ARRAY_SIZE(sx9500_non_readable_reg_ranges),
179 };
180 
181 static const struct regmap_range sx9500_volatile_reg_ranges[] = {
182 	regmap_reg_range(SX9500_REG_IRQ_SRC, SX9500_REG_STAT),
183 	regmap_reg_range(SX9500_REG_USE_MSB, SX9500_REG_OFFSET_LSB),
184 	regmap_reg_range(SX9500_REG_RESET, SX9500_REG_RESET),
185 };
186 
187 static const struct regmap_access_table sx9500_volatile_regs = {
188 	.yes_ranges = sx9500_volatile_reg_ranges,
189 	.n_yes_ranges = ARRAY_SIZE(sx9500_volatile_reg_ranges),
190 };
191 
192 static const struct regmap_config sx9500_regmap_config = {
193 	.reg_bits = 8,
194 	.val_bits = 8,
195 
196 	.max_register = SX9500_REG_RESET,
197 	.cache_type = REGCACHE_RBTREE,
198 
199 	.wr_table = &sx9500_writeable_regs,
200 	.rd_table = &sx9500_readable_regs,
201 	.volatile_table = &sx9500_volatile_regs,
202 };
203 
204 static int sx9500_inc_users(struct sx9500_data *data, int *counter,
205 			    unsigned int reg, unsigned int bitmask)
206 {
207 	(*counter)++;
208 	if (*counter != 1)
209 		/* Bit is already active, nothing to do. */
210 		return 0;
211 
212 	return regmap_set_bits(data->regmap, reg, bitmask);
213 }
214 
215 static int sx9500_dec_users(struct sx9500_data *data, int *counter,
216 			    unsigned int reg, unsigned int bitmask)
217 {
218 	(*counter)--;
219 	if (*counter != 0)
220 		/* There are more users, do not deactivate. */
221 		return 0;
222 
223 	return regmap_clear_bits(data->regmap, reg, bitmask);
224 }
225 
226 static int sx9500_inc_chan_users(struct sx9500_data *data, int chan)
227 {
228 	return sx9500_inc_users(data, &data->channel_users[chan],
229 				SX9500_REG_PROX_CTRL0, BIT(chan));
230 }
231 
232 static int sx9500_dec_chan_users(struct sx9500_data *data, int chan)
233 {
234 	return sx9500_dec_users(data, &data->channel_users[chan],
235 				SX9500_REG_PROX_CTRL0, BIT(chan));
236 }
237 
238 static int sx9500_inc_data_rdy_users(struct sx9500_data *data)
239 {
240 	return sx9500_inc_users(data, &data->data_rdy_users,
241 				SX9500_REG_IRQ_MSK, SX9500_CONVDONE_IRQ);
242 }
243 
244 static int sx9500_dec_data_rdy_users(struct sx9500_data *data)
245 {
246 	return sx9500_dec_users(data, &data->data_rdy_users,
247 				SX9500_REG_IRQ_MSK, SX9500_CONVDONE_IRQ);
248 }
249 
250 static int sx9500_inc_close_far_users(struct sx9500_data *data)
251 {
252 	return sx9500_inc_users(data, &data->close_far_users,
253 				SX9500_REG_IRQ_MSK,
254 				SX9500_CLOSE_IRQ | SX9500_FAR_IRQ);
255 }
256 
257 static int sx9500_dec_close_far_users(struct sx9500_data *data)
258 {
259 	return sx9500_dec_users(data, &data->close_far_users,
260 				SX9500_REG_IRQ_MSK,
261 				SX9500_CLOSE_IRQ | SX9500_FAR_IRQ);
262 }
263 
264 static int sx9500_read_prox_data(struct sx9500_data *data,
265 				 const struct iio_chan_spec *chan,
266 				 int *val)
267 {
268 	int ret;
269 	__be16 regval;
270 
271 	ret = regmap_write(data->regmap, SX9500_REG_SENSOR_SEL, chan->channel);
272 	if (ret < 0)
273 		return ret;
274 
275 	ret = regmap_bulk_read(data->regmap, SX9500_REG_USE_MSB, &regval, 2);
276 	if (ret < 0)
277 		return ret;
278 
279 	*val = be16_to_cpu(regval);
280 
281 	return IIO_VAL_INT;
282 }
283 
284 /*
285  * If we have no interrupt support, we have to wait for a scan period
286  * after enabling a channel to get a result.
287  */
288 static int sx9500_wait_for_sample(struct sx9500_data *data)
289 {
290 	int ret;
291 	unsigned int val;
292 
293 	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0, &val);
294 	if (ret < 0)
295 		return ret;
296 
297 	val = (val & SX9500_SCAN_PERIOD_MASK) >> SX9500_SCAN_PERIOD_SHIFT;
298 
299 	msleep(sx9500_scan_period_table[val]);
300 
301 	return 0;
302 }
303 
304 static int sx9500_read_proximity(struct sx9500_data *data,
305 				 const struct iio_chan_spec *chan,
306 				 int *val)
307 {
308 	int ret;
309 
310 	mutex_lock(&data->mutex);
311 
312 	ret = sx9500_inc_chan_users(data, chan->channel);
313 	if (ret < 0)
314 		goto out;
315 
316 	ret = sx9500_inc_data_rdy_users(data);
317 	if (ret < 0)
318 		goto out_dec_chan;
319 
320 	mutex_unlock(&data->mutex);
321 
322 	if (data->client->irq > 0)
323 		ret = wait_for_completion_interruptible(&data->completion);
324 	else
325 		ret = sx9500_wait_for_sample(data);
326 
327 	mutex_lock(&data->mutex);
328 
329 	if (ret < 0)
330 		goto out_dec_data_rdy;
331 
332 	ret = sx9500_read_prox_data(data, chan, val);
333 	if (ret < 0)
334 		goto out_dec_data_rdy;
335 
336 	ret = sx9500_dec_data_rdy_users(data);
337 	if (ret < 0)
338 		goto out_dec_chan;
339 
340 	ret = sx9500_dec_chan_users(data, chan->channel);
341 	if (ret < 0)
342 		goto out;
343 
344 	ret = IIO_VAL_INT;
345 
346 	goto out;
347 
348 out_dec_data_rdy:
349 	sx9500_dec_data_rdy_users(data);
350 out_dec_chan:
351 	sx9500_dec_chan_users(data, chan->channel);
352 out:
353 	mutex_unlock(&data->mutex);
354 	reinit_completion(&data->completion);
355 
356 	return ret;
357 }
358 
359 static int sx9500_read_samp_freq(struct sx9500_data *data,
360 				 int *val, int *val2)
361 {
362 	int ret;
363 	unsigned int regval;
364 
365 	mutex_lock(&data->mutex);
366 	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0, &regval);
367 	mutex_unlock(&data->mutex);
368 
369 	if (ret < 0)
370 		return ret;
371 
372 	regval = (regval & SX9500_SCAN_PERIOD_MASK) >> SX9500_SCAN_PERIOD_SHIFT;
373 	*val = sx9500_samp_freq_table[regval].val;
374 	*val2 = sx9500_samp_freq_table[regval].val2;
375 
376 	return IIO_VAL_INT_PLUS_MICRO;
377 }
378 
379 static int sx9500_read_raw(struct iio_dev *indio_dev,
380 			   const struct iio_chan_spec *chan,
381 			   int *val, int *val2, long mask)
382 {
383 	struct sx9500_data *data = iio_priv(indio_dev);
384 	int ret;
385 
386 	switch (chan->type) {
387 	case IIO_PROXIMITY:
388 		switch (mask) {
389 		case IIO_CHAN_INFO_RAW:
390 			if (!iio_device_claim_direct(indio_dev))
391 				return -EBUSY;
392 			ret = sx9500_read_proximity(data, chan, val);
393 			iio_device_release_direct(indio_dev);
394 			return ret;
395 		case IIO_CHAN_INFO_SAMP_FREQ:
396 			return sx9500_read_samp_freq(data, val, val2);
397 		default:
398 			return -EINVAL;
399 		}
400 	default:
401 		return -EINVAL;
402 	}
403 }
404 
405 static int sx9500_set_samp_freq(struct sx9500_data *data,
406 				int val, int val2)
407 {
408 	int i, ret;
409 
410 	for (i = 0; i < ARRAY_SIZE(sx9500_samp_freq_table); i++)
411 		if (val == sx9500_samp_freq_table[i].val &&
412 		    val2 == sx9500_samp_freq_table[i].val2)
413 			break;
414 
415 	if (i == ARRAY_SIZE(sx9500_samp_freq_table))
416 		return -EINVAL;
417 
418 	mutex_lock(&data->mutex);
419 
420 	ret = regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
421 				 SX9500_SCAN_PERIOD_MASK,
422 				 i << SX9500_SCAN_PERIOD_SHIFT);
423 
424 	mutex_unlock(&data->mutex);
425 
426 	return ret;
427 }
428 
429 static int sx9500_write_raw(struct iio_dev *indio_dev,
430 			    const struct iio_chan_spec *chan,
431 			    int val, int val2, long mask)
432 {
433 	struct sx9500_data *data = iio_priv(indio_dev);
434 
435 	switch (chan->type) {
436 	case IIO_PROXIMITY:
437 		switch (mask) {
438 		case IIO_CHAN_INFO_SAMP_FREQ:
439 			return sx9500_set_samp_freq(data, val, val2);
440 		default:
441 			return -EINVAL;
442 		}
443 	default:
444 		return -EINVAL;
445 	}
446 }
447 
448 static irqreturn_t sx9500_irq_handler(int irq, void *private)
449 {
450 	struct iio_dev *indio_dev = private;
451 	struct sx9500_data *data = iio_priv(indio_dev);
452 
453 	if (data->trigger_enabled)
454 		iio_trigger_poll(data->trig);
455 
456 	/*
457 	 * Even if no event is enabled, we need to wake the thread to
458 	 * clear the interrupt state by reading SX9500_REG_IRQ_SRC.  It
459 	 * is not possible to do that here because regmap_read takes a
460 	 * mutex.
461 	 */
462 	return IRQ_WAKE_THREAD;
463 }
464 
465 static void sx9500_push_events(struct iio_dev *indio_dev)
466 {
467 	int ret;
468 	unsigned int val, chan;
469 	struct sx9500_data *data = iio_priv(indio_dev);
470 
471 	ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
472 	if (ret < 0) {
473 		dev_err(&data->client->dev, "i2c transfer error in irq\n");
474 		return;
475 	}
476 
477 	val >>= SX9500_PROXSTAT_SHIFT;
478 	for (chan = 0; chan < SX9500_NUM_CHANNELS; chan++) {
479 		int dir;
480 		u64 ev;
481 		bool new_prox = val & BIT(chan);
482 
483 		if (!data->event_enabled[chan])
484 			continue;
485 		if (new_prox == data->prox_stat[chan])
486 			/* No change on this channel. */
487 			continue;
488 
489 		dir = new_prox ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
490 		ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan,
491 					  IIO_EV_TYPE_THRESH, dir);
492 		iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev));
493 		data->prox_stat[chan] = new_prox;
494 	}
495 }
496 
497 static irqreturn_t sx9500_irq_thread_handler(int irq, void *private)
498 {
499 	struct iio_dev *indio_dev = private;
500 	struct sx9500_data *data = iio_priv(indio_dev);
501 	int ret;
502 	unsigned int val;
503 
504 	mutex_lock(&data->mutex);
505 
506 	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
507 	if (ret < 0) {
508 		dev_err(&data->client->dev, "i2c transfer error in irq\n");
509 		goto out;
510 	}
511 
512 	if (val & (SX9500_CLOSE_IRQ | SX9500_FAR_IRQ))
513 		sx9500_push_events(indio_dev);
514 
515 	if (val & SX9500_CONVDONE_IRQ)
516 		complete(&data->completion);
517 
518 out:
519 	mutex_unlock(&data->mutex);
520 
521 	return IRQ_HANDLED;
522 }
523 
524 static int sx9500_read_event_config(struct iio_dev *indio_dev,
525 				    const struct iio_chan_spec *chan,
526 				    enum iio_event_type type,
527 				    enum iio_event_direction dir)
528 {
529 	struct sx9500_data *data = iio_priv(indio_dev);
530 
531 	if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
532 	    dir != IIO_EV_DIR_EITHER)
533 		return -EINVAL;
534 
535 	return data->event_enabled[chan->channel];
536 }
537 
538 static int sx9500_write_event_config(struct iio_dev *indio_dev,
539 				     const struct iio_chan_spec *chan,
540 				     enum iio_event_type type,
541 				     enum iio_event_direction dir,
542 				     bool state)
543 {
544 	struct sx9500_data *data = iio_priv(indio_dev);
545 	int ret;
546 
547 	if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
548 	    dir != IIO_EV_DIR_EITHER)
549 		return -EINVAL;
550 
551 	mutex_lock(&data->mutex);
552 
553 	if (state) {
554 		ret = sx9500_inc_chan_users(data, chan->channel);
555 		if (ret < 0)
556 			goto out_unlock;
557 		ret = sx9500_inc_close_far_users(data);
558 		if (ret < 0)
559 			goto out_undo_chan;
560 	} else {
561 		ret = sx9500_dec_chan_users(data, chan->channel);
562 		if (ret < 0)
563 			goto out_unlock;
564 		ret = sx9500_dec_close_far_users(data);
565 		if (ret < 0)
566 			goto out_undo_chan;
567 	}
568 
569 	data->event_enabled[chan->channel] = state;
570 	goto out_unlock;
571 
572 out_undo_chan:
573 	if (state)
574 		sx9500_dec_chan_users(data, chan->channel);
575 	else
576 		sx9500_inc_chan_users(data, chan->channel);
577 out_unlock:
578 	mutex_unlock(&data->mutex);
579 	return ret;
580 }
581 
582 static int sx9500_update_scan_mode(struct iio_dev *indio_dev,
583 				   const unsigned long *scan_mask)
584 {
585 	struct sx9500_data *data = iio_priv(indio_dev);
586 
587 	mutex_lock(&data->mutex);
588 	kfree(data->buffer);
589 	data->buffer = kzalloc(indio_dev->scan_bytes, GFP_KERNEL);
590 	mutex_unlock(&data->mutex);
591 
592 	if (data->buffer == NULL)
593 		return -ENOMEM;
594 
595 	return 0;
596 }
597 
598 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
599 	"2.500000 3.333333 5 6.666666 8.333333 11.111111 16.666666 33.333333");
600 
601 static struct attribute *sx9500_attributes[] = {
602 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
603 	NULL,
604 };
605 
606 static const struct attribute_group sx9500_attribute_group = {
607 	.attrs = sx9500_attributes,
608 };
609 
610 static const struct iio_info sx9500_info = {
611 	.attrs = &sx9500_attribute_group,
612 	.read_raw = &sx9500_read_raw,
613 	.write_raw = &sx9500_write_raw,
614 	.read_event_config = &sx9500_read_event_config,
615 	.write_event_config = &sx9500_write_event_config,
616 	.update_scan_mode = &sx9500_update_scan_mode,
617 };
618 
619 static int sx9500_set_trigger_state(struct iio_trigger *trig,
620 				    bool state)
621 {
622 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
623 	struct sx9500_data *data = iio_priv(indio_dev);
624 	int ret;
625 
626 	mutex_lock(&data->mutex);
627 
628 	if (state)
629 		ret = sx9500_inc_data_rdy_users(data);
630 	else
631 		ret = sx9500_dec_data_rdy_users(data);
632 	if (ret < 0)
633 		goto out;
634 
635 	data->trigger_enabled = state;
636 
637 out:
638 	mutex_unlock(&data->mutex);
639 
640 	return ret;
641 }
642 
643 static const struct iio_trigger_ops sx9500_trigger_ops = {
644 	.set_trigger_state = sx9500_set_trigger_state,
645 };
646 
647 static irqreturn_t sx9500_trigger_handler(int irq, void *private)
648 {
649 	struct iio_poll_func *pf = private;
650 	struct iio_dev *indio_dev = pf->indio_dev;
651 	struct sx9500_data *data = iio_priv(indio_dev);
652 	int val, bit, ret, i = 0;
653 
654 	mutex_lock(&data->mutex);
655 
656 	iio_for_each_active_channel(indio_dev, bit) {
657 		ret = sx9500_read_prox_data(data, &indio_dev->channels[bit],
658 					    &val);
659 		if (ret < 0)
660 			goto out;
661 
662 		data->buffer[i++] = val;
663 	}
664 
665 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
666 					   iio_get_time_ns(indio_dev));
667 
668 out:
669 	mutex_unlock(&data->mutex);
670 
671 	iio_trigger_notify_done(indio_dev->trig);
672 
673 	return IRQ_HANDLED;
674 }
675 
676 static int sx9500_buffer_postenable(struct iio_dev *indio_dev)
677 {
678 	struct sx9500_data *data = iio_priv(indio_dev);
679 	int ret = 0, i;
680 
681 	mutex_lock(&data->mutex);
682 
683 	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
684 		if (test_bit(i, indio_dev->active_scan_mask)) {
685 			ret = sx9500_inc_chan_users(data, i);
686 			if (ret)
687 				break;
688 		}
689 
690 	if (ret)
691 		for (i = i - 1; i >= 0; i--)
692 			if (test_bit(i, indio_dev->active_scan_mask))
693 				sx9500_dec_chan_users(data, i);
694 
695 	mutex_unlock(&data->mutex);
696 
697 	return ret;
698 }
699 
700 static int sx9500_buffer_predisable(struct iio_dev *indio_dev)
701 {
702 	struct sx9500_data *data = iio_priv(indio_dev);
703 	int ret = 0, i;
704 
705 	mutex_lock(&data->mutex);
706 
707 	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
708 		if (test_bit(i, indio_dev->active_scan_mask)) {
709 			ret = sx9500_dec_chan_users(data, i);
710 			if (ret)
711 				break;
712 		}
713 
714 	if (ret)
715 		for (i = i - 1; i >= 0; i--)
716 			if (test_bit(i, indio_dev->active_scan_mask))
717 				sx9500_inc_chan_users(data, i);
718 
719 	mutex_unlock(&data->mutex);
720 
721 	return ret;
722 }
723 
724 static const struct iio_buffer_setup_ops sx9500_buffer_setup_ops = {
725 	.postenable = sx9500_buffer_postenable,
726 	.predisable = sx9500_buffer_predisable,
727 };
728 
729 struct sx9500_reg_default {
730 	u8 reg;
731 	u8 def;
732 };
733 
734 static const struct sx9500_reg_default sx9500_default_regs[] = {
735 	{
736 		.reg = SX9500_REG_PROX_CTRL1,
737 		/* Shield enabled, small range. */
738 		.def = 0x43,
739 	},
740 	{
741 		.reg = SX9500_REG_PROX_CTRL2,
742 		/* x8 gain, 167kHz frequency, finest resolution. */
743 		.def = 0x77,
744 	},
745 	{
746 		.reg = SX9500_REG_PROX_CTRL3,
747 		/* Doze enabled, 2x scan period doze, no raw filter. */
748 		.def = 0x40,
749 	},
750 	{
751 		.reg = SX9500_REG_PROX_CTRL4,
752 		/* Average threshold. */
753 		.def = 0x30,
754 	},
755 	{
756 		.reg = SX9500_REG_PROX_CTRL5,
757 		/*
758 		 * Debouncer off, lowest average negative filter,
759 		 * highest average positive filter.
760 		 */
761 		.def = 0x0f,
762 	},
763 	{
764 		.reg = SX9500_REG_PROX_CTRL6,
765 		/* Proximity detection threshold: 280 */
766 		.def = 0x0e,
767 	},
768 	{
769 		.reg = SX9500_REG_PROX_CTRL7,
770 		/*
771 		 * No automatic compensation, compensate each pin
772 		 * independently, proximity hysteresis: 32, close
773 		 * debouncer off, far debouncer off.
774 		 */
775 		.def = 0x00,
776 	},
777 	{
778 		.reg = SX9500_REG_PROX_CTRL8,
779 		/* No stuck timeout, no periodic compensation. */
780 		.def = 0x00,
781 	},
782 	{
783 		.reg = SX9500_REG_PROX_CTRL0,
784 		/* Scan period: 30ms, all sensors disabled. */
785 		.def = 0x00,
786 	},
787 };
788 
789 /* Activate all channels and perform an initial compensation. */
790 static int sx9500_init_compensation(struct iio_dev *indio_dev)
791 {
792 	struct sx9500_data *data = iio_priv(indio_dev);
793 	int i, ret;
794 	unsigned int val;
795 
796 	ret = regmap_set_bits(data->regmap, SX9500_REG_PROX_CTRL0,
797 			      SX9500_CHAN_MASK);
798 	if (ret < 0)
799 		return ret;
800 
801 	for (i = 10; i >= 0; i--) {
802 		usleep_range(10000, 20000);
803 		ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
804 		if (ret < 0)
805 			goto out;
806 		if (!(val & SX9500_COMPSTAT_MASK))
807 			break;
808 	}
809 
810 	if (i < 0) {
811 		dev_err(&data->client->dev, "initial compensation timed out");
812 		ret = -ETIMEDOUT;
813 	}
814 
815 out:
816 	regmap_clear_bits(data->regmap, SX9500_REG_PROX_CTRL0,
817 			  SX9500_CHAN_MASK);
818 	return ret;
819 }
820 
821 static int sx9500_init_device(struct iio_dev *indio_dev)
822 {
823 	struct sx9500_data *data = iio_priv(indio_dev);
824 	int ret, i;
825 	unsigned int val;
826 
827 	if (data->gpiod_rst) {
828 		gpiod_set_value_cansleep(data->gpiod_rst, 0);
829 		usleep_range(1000, 2000);
830 		gpiod_set_value_cansleep(data->gpiod_rst, 1);
831 		usleep_range(1000, 2000);
832 	}
833 
834 	ret = regmap_write(data->regmap, SX9500_REG_IRQ_MSK, 0);
835 	if (ret < 0)
836 		return ret;
837 
838 	ret = regmap_write(data->regmap, SX9500_REG_RESET,
839 			   SX9500_SOFT_RESET);
840 	if (ret < 0)
841 		return ret;
842 
843 	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
844 	if (ret < 0)
845 		return ret;
846 
847 	for (i = 0; i < ARRAY_SIZE(sx9500_default_regs); i++) {
848 		ret = regmap_write(data->regmap,
849 				   sx9500_default_regs[i].reg,
850 				   sx9500_default_regs[i].def);
851 		if (ret < 0)
852 			return ret;
853 	}
854 
855 	return sx9500_init_compensation(indio_dev);
856 }
857 
858 static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
859 static const struct acpi_gpio_params interrupt_gpios = { 2, 0, false };
860 
861 static const struct acpi_gpio_mapping acpi_sx9500_gpios[] = {
862 	{ "reset-gpios", &reset_gpios, 1 },
863 	/*
864 	 * Some platforms have a bug in ACPI GPIO description making IRQ
865 	 * GPIO to be output only. Ask the GPIO core to ignore this limit.
866 	 */
867 	{ "interrupt-gpios", &interrupt_gpios, 1, ACPI_GPIO_QUIRK_NO_IO_RESTRICTION },
868 	{ }
869 };
870 
871 static void sx9500_gpio_probe(struct i2c_client *client,
872 			      struct sx9500_data *data)
873 {
874 	struct gpio_desc *gpiod_int;
875 	struct device *dev;
876 	int ret;
877 
878 	if (!client)
879 		return;
880 
881 	dev = &client->dev;
882 
883 	ret = devm_acpi_dev_add_driver_gpios(dev, acpi_sx9500_gpios);
884 	if (ret)
885 		dev_dbg(dev, "Unable to add GPIO mapping table\n");
886 
887 	if (client->irq <= 0) {
888 		gpiod_int = devm_gpiod_get(dev, "interrupt", GPIOD_IN);
889 		if (IS_ERR(gpiod_int))
890 			dev_err(dev, "gpio get irq failed\n");
891 		else
892 			client->irq = gpiod_to_irq(gpiod_int);
893 	}
894 
895 	data->gpiod_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
896 	if (IS_ERR(data->gpiod_rst)) {
897 		dev_warn(dev, "gpio get reset pin failed\n");
898 		data->gpiod_rst = NULL;
899 	}
900 }
901 
902 static int sx9500_probe(struct i2c_client *client)
903 {
904 	int ret;
905 	struct iio_dev *indio_dev;
906 	struct sx9500_data *data;
907 
908 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
909 	if (indio_dev == NULL)
910 		return -ENOMEM;
911 
912 	data = iio_priv(indio_dev);
913 	data->client = client;
914 	mutex_init(&data->mutex);
915 	init_completion(&data->completion);
916 	data->trigger_enabled = false;
917 
918 	data->regmap = devm_regmap_init_i2c(client, &sx9500_regmap_config);
919 	if (IS_ERR(data->regmap))
920 		return PTR_ERR(data->regmap);
921 
922 	indio_dev->name = SX9500_DRIVER_NAME;
923 	indio_dev->channels = sx9500_channels;
924 	indio_dev->num_channels = ARRAY_SIZE(sx9500_channels);
925 	indio_dev->info = &sx9500_info;
926 	indio_dev->modes = INDIO_DIRECT_MODE;
927 	i2c_set_clientdata(client, indio_dev);
928 
929 	sx9500_gpio_probe(client, data);
930 
931 	ret = sx9500_init_device(indio_dev);
932 	if (ret < 0)
933 		return ret;
934 
935 	if (client->irq <= 0)
936 		dev_warn(&client->dev, "no valid irq found\n");
937 	else {
938 		ret = devm_request_threaded_irq(&client->dev, client->irq,
939 				sx9500_irq_handler, sx9500_irq_thread_handler,
940 				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
941 				SX9500_IRQ_NAME, indio_dev);
942 		if (ret < 0)
943 			return ret;
944 
945 		data->trig = devm_iio_trigger_alloc(&client->dev,
946 				"%s-dev%d", indio_dev->name, iio_device_id(indio_dev));
947 		if (!data->trig)
948 			return -ENOMEM;
949 
950 		data->trig->ops = &sx9500_trigger_ops;
951 		iio_trigger_set_drvdata(data->trig, indio_dev);
952 
953 		ret = iio_trigger_register(data->trig);
954 		if (ret)
955 			return ret;
956 	}
957 
958 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
959 					 sx9500_trigger_handler,
960 					 &sx9500_buffer_setup_ops);
961 	if (ret < 0)
962 		goto out_trigger_unregister;
963 
964 	ret = iio_device_register(indio_dev);
965 	if (ret < 0)
966 		goto out_buffer_cleanup;
967 
968 	return 0;
969 
970 out_buffer_cleanup:
971 	iio_triggered_buffer_cleanup(indio_dev);
972 out_trigger_unregister:
973 	if (client->irq > 0)
974 		iio_trigger_unregister(data->trig);
975 
976 	return ret;
977 }
978 
979 static void sx9500_remove(struct i2c_client *client)
980 {
981 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
982 	struct sx9500_data *data = iio_priv(indio_dev);
983 
984 	iio_device_unregister(indio_dev);
985 	iio_triggered_buffer_cleanup(indio_dev);
986 	if (client->irq > 0)
987 		iio_trigger_unregister(data->trig);
988 	kfree(data->buffer);
989 }
990 
991 static int sx9500_suspend(struct device *dev)
992 {
993 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
994 	struct sx9500_data *data = iio_priv(indio_dev);
995 	int ret;
996 
997 	mutex_lock(&data->mutex);
998 	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0,
999 			  &data->suspend_ctrl0);
1000 	if (ret < 0)
1001 		goto out;
1002 
1003 	/*
1004 	 * Scan period doesn't matter because when all the sensors are
1005 	 * deactivated the device is in sleep mode.
1006 	 */
1007 	ret = regmap_write(data->regmap, SX9500_REG_PROX_CTRL0, 0);
1008 
1009 out:
1010 	mutex_unlock(&data->mutex);
1011 	return ret;
1012 }
1013 
1014 static int sx9500_resume(struct device *dev)
1015 {
1016 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
1017 	struct sx9500_data *data = iio_priv(indio_dev);
1018 	int ret;
1019 
1020 	mutex_lock(&data->mutex);
1021 	ret = regmap_write(data->regmap, SX9500_REG_PROX_CTRL0,
1022 			   data->suspend_ctrl0);
1023 	mutex_unlock(&data->mutex);
1024 
1025 	return ret;
1026 }
1027 
1028 static DEFINE_SIMPLE_DEV_PM_OPS(sx9500_pm_ops, sx9500_suspend, sx9500_resume);
1029 
1030 static const struct acpi_device_id sx9500_acpi_match[] = {
1031 	{"SSX9500", 0},
1032 	{"SASX9500", 0},
1033 	{ }
1034 };
1035 MODULE_DEVICE_TABLE(acpi, sx9500_acpi_match);
1036 
1037 static const struct of_device_id sx9500_of_match[] = {
1038 	{ .compatible = "semtech,sx9500", },
1039 	{ }
1040 };
1041 MODULE_DEVICE_TABLE(of, sx9500_of_match);
1042 
1043 static const struct i2c_device_id sx9500_id[] = {
1044 	{ "sx9500" },
1045 	{ }
1046 };
1047 MODULE_DEVICE_TABLE(i2c, sx9500_id);
1048 
1049 static struct i2c_driver sx9500_driver = {
1050 	.driver = {
1051 		.name	= SX9500_DRIVER_NAME,
1052 		.acpi_match_table = sx9500_acpi_match,
1053 		.of_match_table = sx9500_of_match,
1054 		.pm = pm_sleep_ptr(&sx9500_pm_ops),
1055 	},
1056 	.probe		= sx9500_probe,
1057 	.remove		= sx9500_remove,
1058 	.id_table	= sx9500_id,
1059 };
1060 module_i2c_driver(sx9500_driver);
1061 
1062 MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
1063 MODULE_DESCRIPTION("Driver for Semtech SX9500 proximity sensor");
1064 MODULE_LICENSE("GPL v2");
1065