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
79struct 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
100static 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
126static 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
134static 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
148static const unsigned int sx9500_scan_period_table[] = {
149	30, 60, 90, 120, 150, 200, 300, 400,
150};
151
152static 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
160static 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 */
169static 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
176static 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
181static 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
187static 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
192static 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
204static 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_update_bits(data->regmap, reg, bitmask, bitmask);
213}
214
215static 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_update_bits(data->regmap, reg, bitmask, 0);
224}
225
226static 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
232static 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
238static 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
244static 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
250static 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
257static 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
264static 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 */
288static 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
304static 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
348out_dec_data_rdy:
349	sx9500_dec_data_rdy_users(data);
350out_dec_chan:
351	sx9500_dec_chan_users(data, chan->channel);
352out:
353	mutex_unlock(&data->mutex);
354	reinit_completion(&data->completion);
355
356	return ret;
357}
358
359static 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
379static 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			ret = iio_device_claim_direct_mode(indio_dev);
391			if (ret)
392				return ret;
393			ret = sx9500_read_proximity(data, chan, val);
394			iio_device_release_direct_mode(indio_dev);
395			return ret;
396		case IIO_CHAN_INFO_SAMP_FREQ:
397			return sx9500_read_samp_freq(data, val, val2);
398		default:
399			return -EINVAL;
400		}
401	default:
402		return -EINVAL;
403	}
404}
405
406static int sx9500_set_samp_freq(struct sx9500_data *data,
407				int val, int val2)
408{
409	int i, ret;
410
411	for (i = 0; i < ARRAY_SIZE(sx9500_samp_freq_table); i++)
412		if (val == sx9500_samp_freq_table[i].val &&
413		    val2 == sx9500_samp_freq_table[i].val2)
414			break;
415
416	if (i == ARRAY_SIZE(sx9500_samp_freq_table))
417		return -EINVAL;
418
419	mutex_lock(&data->mutex);
420
421	ret = regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
422				 SX9500_SCAN_PERIOD_MASK,
423				 i << SX9500_SCAN_PERIOD_SHIFT);
424
425	mutex_unlock(&data->mutex);
426
427	return ret;
428}
429
430static int sx9500_write_raw(struct iio_dev *indio_dev,
431			    const struct iio_chan_spec *chan,
432			    int val, int val2, long mask)
433{
434	struct sx9500_data *data = iio_priv(indio_dev);
435
436	switch (chan->type) {
437	case IIO_PROXIMITY:
438		switch (mask) {
439		case IIO_CHAN_INFO_SAMP_FREQ:
440			return sx9500_set_samp_freq(data, val, val2);
441		default:
442			return -EINVAL;
443		}
444	default:
445		return -EINVAL;
446	}
447}
448
449static irqreturn_t sx9500_irq_handler(int irq, void *private)
450{
451	struct iio_dev *indio_dev = private;
452	struct sx9500_data *data = iio_priv(indio_dev);
453
454	if (data->trigger_enabled)
455		iio_trigger_poll(data->trig);
456
457	/*
458	 * Even if no event is enabled, we need to wake the thread to
459	 * clear the interrupt state by reading SX9500_REG_IRQ_SRC.  It
460	 * is not possible to do that here because regmap_read takes a
461	 * mutex.
462	 */
463	return IRQ_WAKE_THREAD;
464}
465
466static void sx9500_push_events(struct iio_dev *indio_dev)
467{
468	int ret;
469	unsigned int val, chan;
470	struct sx9500_data *data = iio_priv(indio_dev);
471
472	ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
473	if (ret < 0) {
474		dev_err(&data->client->dev, "i2c transfer error in irq\n");
475		return;
476	}
477
478	val >>= SX9500_PROXSTAT_SHIFT;
479	for (chan = 0; chan < SX9500_NUM_CHANNELS; chan++) {
480		int dir;
481		u64 ev;
482		bool new_prox = val & BIT(chan);
483
484		if (!data->event_enabled[chan])
485			continue;
486		if (new_prox == data->prox_stat[chan])
487			/* No change on this channel. */
488			continue;
489
490		dir = new_prox ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
491		ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan,
492					  IIO_EV_TYPE_THRESH, dir);
493		iio_push_event(indio_dev, ev, iio_get_time_ns(indio_dev));
494		data->prox_stat[chan] = new_prox;
495	}
496}
497
498static irqreturn_t sx9500_irq_thread_handler(int irq, void *private)
499{
500	struct iio_dev *indio_dev = private;
501	struct sx9500_data *data = iio_priv(indio_dev);
502	int ret;
503	unsigned int val;
504
505	mutex_lock(&data->mutex);
506
507	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
508	if (ret < 0) {
509		dev_err(&data->client->dev, "i2c transfer error in irq\n");
510		goto out;
511	}
512
513	if (val & (SX9500_CLOSE_IRQ | SX9500_FAR_IRQ))
514		sx9500_push_events(indio_dev);
515
516	if (val & SX9500_CONVDONE_IRQ)
517		complete(&data->completion);
518
519out:
520	mutex_unlock(&data->mutex);
521
522	return IRQ_HANDLED;
523}
524
525static int sx9500_read_event_config(struct iio_dev *indio_dev,
526				    const struct iio_chan_spec *chan,
527				    enum iio_event_type type,
528				    enum iio_event_direction dir)
529{
530	struct sx9500_data *data = iio_priv(indio_dev);
531
532	if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
533	    dir != IIO_EV_DIR_EITHER)
534		return -EINVAL;
535
536	return data->event_enabled[chan->channel];
537}
538
539static int sx9500_write_event_config(struct iio_dev *indio_dev,
540				     const struct iio_chan_spec *chan,
541				     enum iio_event_type type,
542				     enum iio_event_direction dir,
543				     int state)
544{
545	struct sx9500_data *data = iio_priv(indio_dev);
546	int ret;
547
548	if (chan->type != IIO_PROXIMITY || type != IIO_EV_TYPE_THRESH ||
549	    dir != IIO_EV_DIR_EITHER)
550		return -EINVAL;
551
552	mutex_lock(&data->mutex);
553
554	if (state == 1) {
555		ret = sx9500_inc_chan_users(data, chan->channel);
556		if (ret < 0)
557			goto out_unlock;
558		ret = sx9500_inc_close_far_users(data);
559		if (ret < 0)
560			goto out_undo_chan;
561	} else {
562		ret = sx9500_dec_chan_users(data, chan->channel);
563		if (ret < 0)
564			goto out_unlock;
565		ret = sx9500_dec_close_far_users(data);
566		if (ret < 0)
567			goto out_undo_chan;
568	}
569
570	data->event_enabled[chan->channel] = state;
571	goto out_unlock;
572
573out_undo_chan:
574	if (state == 1)
575		sx9500_dec_chan_users(data, chan->channel);
576	else
577		sx9500_inc_chan_users(data, chan->channel);
578out_unlock:
579	mutex_unlock(&data->mutex);
580	return ret;
581}
582
583static int sx9500_update_scan_mode(struct iio_dev *indio_dev,
584				   const unsigned long *scan_mask)
585{
586	struct sx9500_data *data = iio_priv(indio_dev);
587
588	mutex_lock(&data->mutex);
589	kfree(data->buffer);
590	data->buffer = kzalloc(indio_dev->scan_bytes, GFP_KERNEL);
591	mutex_unlock(&data->mutex);
592
593	if (data->buffer == NULL)
594		return -ENOMEM;
595
596	return 0;
597}
598
599static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(
600	"2.500000 3.333333 5 6.666666 8.333333 11.111111 16.666666 33.333333");
601
602static struct attribute *sx9500_attributes[] = {
603	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
604	NULL,
605};
606
607static const struct attribute_group sx9500_attribute_group = {
608	.attrs = sx9500_attributes,
609};
610
611static const struct iio_info sx9500_info = {
612	.attrs = &sx9500_attribute_group,
613	.read_raw = &sx9500_read_raw,
614	.write_raw = &sx9500_write_raw,
615	.read_event_config = &sx9500_read_event_config,
616	.write_event_config = &sx9500_write_event_config,
617	.update_scan_mode = &sx9500_update_scan_mode,
618};
619
620static int sx9500_set_trigger_state(struct iio_trigger *trig,
621				    bool state)
622{
623	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
624	struct sx9500_data *data = iio_priv(indio_dev);
625	int ret;
626
627	mutex_lock(&data->mutex);
628
629	if (state)
630		ret = sx9500_inc_data_rdy_users(data);
631	else
632		ret = sx9500_dec_data_rdy_users(data);
633	if (ret < 0)
634		goto out;
635
636	data->trigger_enabled = state;
637
638out:
639	mutex_unlock(&data->mutex);
640
641	return ret;
642}
643
644static const struct iio_trigger_ops sx9500_trigger_ops = {
645	.set_trigger_state = sx9500_set_trigger_state,
646};
647
648static irqreturn_t sx9500_trigger_handler(int irq, void *private)
649{
650	struct iio_poll_func *pf = private;
651	struct iio_dev *indio_dev = pf->indio_dev;
652	struct sx9500_data *data = iio_priv(indio_dev);
653	int val, bit, ret, i = 0;
654
655	mutex_lock(&data->mutex);
656
657	for_each_set_bit(bit, indio_dev->active_scan_mask,
658			 indio_dev->masklength) {
659		ret = sx9500_read_prox_data(data, &indio_dev->channels[bit],
660					    &val);
661		if (ret < 0)
662			goto out;
663
664		data->buffer[i++] = val;
665	}
666
667	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
668					   iio_get_time_ns(indio_dev));
669
670out:
671	mutex_unlock(&data->mutex);
672
673	iio_trigger_notify_done(indio_dev->trig);
674
675	return IRQ_HANDLED;
676}
677
678static int sx9500_buffer_postenable(struct iio_dev *indio_dev)
679{
680	struct sx9500_data *data = iio_priv(indio_dev);
681	int ret = 0, i;
682
683	mutex_lock(&data->mutex);
684
685	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
686		if (test_bit(i, indio_dev->active_scan_mask)) {
687			ret = sx9500_inc_chan_users(data, i);
688			if (ret)
689				break;
690		}
691
692	if (ret)
693		for (i = i - 1; i >= 0; i--)
694			if (test_bit(i, indio_dev->active_scan_mask))
695				sx9500_dec_chan_users(data, i);
696
697	mutex_unlock(&data->mutex);
698
699	return ret;
700}
701
702static int sx9500_buffer_predisable(struct iio_dev *indio_dev)
703{
704	struct sx9500_data *data = iio_priv(indio_dev);
705	int ret = 0, i;
706
707	mutex_lock(&data->mutex);
708
709	for (i = 0; i < SX9500_NUM_CHANNELS; i++)
710		if (test_bit(i, indio_dev->active_scan_mask)) {
711			ret = sx9500_dec_chan_users(data, i);
712			if (ret)
713				break;
714		}
715
716	if (ret)
717		for (i = i - 1; i >= 0; i--)
718			if (test_bit(i, indio_dev->active_scan_mask))
719				sx9500_inc_chan_users(data, i);
720
721	mutex_unlock(&data->mutex);
722
723	return ret;
724}
725
726static const struct iio_buffer_setup_ops sx9500_buffer_setup_ops = {
727	.postenable = sx9500_buffer_postenable,
728	.predisable = sx9500_buffer_predisable,
729};
730
731struct sx9500_reg_default {
732	u8 reg;
733	u8 def;
734};
735
736static const struct sx9500_reg_default sx9500_default_regs[] = {
737	{
738		.reg = SX9500_REG_PROX_CTRL1,
739		/* Shield enabled, small range. */
740		.def = 0x43,
741	},
742	{
743		.reg = SX9500_REG_PROX_CTRL2,
744		/* x8 gain, 167kHz frequency, finest resolution. */
745		.def = 0x77,
746	},
747	{
748		.reg = SX9500_REG_PROX_CTRL3,
749		/* Doze enabled, 2x scan period doze, no raw filter. */
750		.def = 0x40,
751	},
752	{
753		.reg = SX9500_REG_PROX_CTRL4,
754		/* Average threshold. */
755		.def = 0x30,
756	},
757	{
758		.reg = SX9500_REG_PROX_CTRL5,
759		/*
760		 * Debouncer off, lowest average negative filter,
761		 * highest average positive filter.
762		 */
763		.def = 0x0f,
764	},
765	{
766		.reg = SX9500_REG_PROX_CTRL6,
767		/* Proximity detection threshold: 280 */
768		.def = 0x0e,
769	},
770	{
771		.reg = SX9500_REG_PROX_CTRL7,
772		/*
773		 * No automatic compensation, compensate each pin
774		 * independently, proximity hysteresis: 32, close
775		 * debouncer off, far debouncer off.
776		 */
777		.def = 0x00,
778	},
779	{
780		.reg = SX9500_REG_PROX_CTRL8,
781		/* No stuck timeout, no periodic compensation. */
782		.def = 0x00,
783	},
784	{
785		.reg = SX9500_REG_PROX_CTRL0,
786		/* Scan period: 30ms, all sensors disabled. */
787		.def = 0x00,
788	},
789};
790
791/* Activate all channels and perform an initial compensation. */
792static int sx9500_init_compensation(struct iio_dev *indio_dev)
793{
794	struct sx9500_data *data = iio_priv(indio_dev);
795	int i, ret;
796	unsigned int val;
797
798	ret = regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
799				 SX9500_CHAN_MASK, SX9500_CHAN_MASK);
800	if (ret < 0)
801		return ret;
802
803	for (i = 10; i >= 0; i--) {
804		usleep_range(10000, 20000);
805		ret = regmap_read(data->regmap, SX9500_REG_STAT, &val);
806		if (ret < 0)
807			goto out;
808		if (!(val & SX9500_COMPSTAT_MASK))
809			break;
810	}
811
812	if (i < 0) {
813		dev_err(&data->client->dev, "initial compensation timed out");
814		ret = -ETIMEDOUT;
815	}
816
817out:
818	regmap_update_bits(data->regmap, SX9500_REG_PROX_CTRL0,
819			   SX9500_CHAN_MASK, 0);
820	return ret;
821}
822
823static int sx9500_init_device(struct iio_dev *indio_dev)
824{
825	struct sx9500_data *data = iio_priv(indio_dev);
826	int ret, i;
827	unsigned int val;
828
829	if (data->gpiod_rst) {
830		gpiod_set_value_cansleep(data->gpiod_rst, 0);
831		usleep_range(1000, 2000);
832		gpiod_set_value_cansleep(data->gpiod_rst, 1);
833		usleep_range(1000, 2000);
834	}
835
836	ret = regmap_write(data->regmap, SX9500_REG_IRQ_MSK, 0);
837	if (ret < 0)
838		return ret;
839
840	ret = regmap_write(data->regmap, SX9500_REG_RESET,
841			   SX9500_SOFT_RESET);
842	if (ret < 0)
843		return ret;
844
845	ret = regmap_read(data->regmap, SX9500_REG_IRQ_SRC, &val);
846	if (ret < 0)
847		return ret;
848
849	for (i = 0; i < ARRAY_SIZE(sx9500_default_regs); i++) {
850		ret = regmap_write(data->regmap,
851				   sx9500_default_regs[i].reg,
852				   sx9500_default_regs[i].def);
853		if (ret < 0)
854			return ret;
855	}
856
857	return sx9500_init_compensation(indio_dev);
858}
859
860static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
861static const struct acpi_gpio_params interrupt_gpios = { 2, 0, false };
862
863static const struct acpi_gpio_mapping acpi_sx9500_gpios[] = {
864	{ "reset-gpios", &reset_gpios, 1 },
865	/*
866	 * Some platforms have a bug in ACPI GPIO description making IRQ
867	 * GPIO to be output only. Ask the GPIO core to ignore this limit.
868	 */
869	{ "interrupt-gpios", &interrupt_gpios, 1, ACPI_GPIO_QUIRK_NO_IO_RESTRICTION },
870	{ },
871};
872
873static void sx9500_gpio_probe(struct i2c_client *client,
874			      struct sx9500_data *data)
875{
876	struct gpio_desc *gpiod_int;
877	struct device *dev;
878	int ret;
879
880	if (!client)
881		return;
882
883	dev = &client->dev;
884
885	ret = devm_acpi_dev_add_driver_gpios(dev, acpi_sx9500_gpios);
886	if (ret)
887		dev_dbg(dev, "Unable to add GPIO mapping table\n");
888
889	if (client->irq <= 0) {
890		gpiod_int = devm_gpiod_get(dev, "interrupt", GPIOD_IN);
891		if (IS_ERR(gpiod_int))
892			dev_err(dev, "gpio get irq failed\n");
893		else
894			client->irq = gpiod_to_irq(gpiod_int);
895	}
896
897	data->gpiod_rst = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
898	if (IS_ERR(data->gpiod_rst)) {
899		dev_warn(dev, "gpio get reset pin failed\n");
900		data->gpiod_rst = NULL;
901	}
902}
903
904static int sx9500_probe(struct i2c_client *client)
905{
906	int ret;
907	struct iio_dev *indio_dev;
908	struct sx9500_data *data;
909
910	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
911	if (indio_dev == NULL)
912		return -ENOMEM;
913
914	data = iio_priv(indio_dev);
915	data->client = client;
916	mutex_init(&data->mutex);
917	init_completion(&data->completion);
918	data->trigger_enabled = false;
919
920	data->regmap = devm_regmap_init_i2c(client, &sx9500_regmap_config);
921	if (IS_ERR(data->regmap))
922		return PTR_ERR(data->regmap);
923
924	indio_dev->name = SX9500_DRIVER_NAME;
925	indio_dev->channels = sx9500_channels;
926	indio_dev->num_channels = ARRAY_SIZE(sx9500_channels);
927	indio_dev->info = &sx9500_info;
928	indio_dev->modes = INDIO_DIRECT_MODE;
929	i2c_set_clientdata(client, indio_dev);
930
931	sx9500_gpio_probe(client, data);
932
933	ret = sx9500_init_device(indio_dev);
934	if (ret < 0)
935		return ret;
936
937	if (client->irq <= 0)
938		dev_warn(&client->dev, "no valid irq found\n");
939	else {
940		ret = devm_request_threaded_irq(&client->dev, client->irq,
941				sx9500_irq_handler, sx9500_irq_thread_handler,
942				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
943				SX9500_IRQ_NAME, indio_dev);
944		if (ret < 0)
945			return ret;
946
947		data->trig = devm_iio_trigger_alloc(&client->dev,
948				"%s-dev%d", indio_dev->name, iio_device_id(indio_dev));
949		if (!data->trig)
950			return -ENOMEM;
951
952		data->trig->ops = &sx9500_trigger_ops;
953		iio_trigger_set_drvdata(data->trig, indio_dev);
954
955		ret = iio_trigger_register(data->trig);
956		if (ret)
957			return ret;
958	}
959
960	ret = iio_triggered_buffer_setup(indio_dev, NULL,
961					 sx9500_trigger_handler,
962					 &sx9500_buffer_setup_ops);
963	if (ret < 0)
964		goto out_trigger_unregister;
965
966	ret = iio_device_register(indio_dev);
967	if (ret < 0)
968		goto out_buffer_cleanup;
969
970	return 0;
971
972out_buffer_cleanup:
973	iio_triggered_buffer_cleanup(indio_dev);
974out_trigger_unregister:
975	if (client->irq > 0)
976		iio_trigger_unregister(data->trig);
977
978	return ret;
979}
980
981static void sx9500_remove(struct i2c_client *client)
982{
983	struct iio_dev *indio_dev = i2c_get_clientdata(client);
984	struct sx9500_data *data = iio_priv(indio_dev);
985
986	iio_device_unregister(indio_dev);
987	iio_triggered_buffer_cleanup(indio_dev);
988	if (client->irq > 0)
989		iio_trigger_unregister(data->trig);
990	kfree(data->buffer);
991}
992
993static int sx9500_suspend(struct device *dev)
994{
995	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
996	struct sx9500_data *data = iio_priv(indio_dev);
997	int ret;
998
999	mutex_lock(&data->mutex);
1000	ret = regmap_read(data->regmap, SX9500_REG_PROX_CTRL0,
1001			  &data->suspend_ctrl0);
1002	if (ret < 0)
1003		goto out;
1004
1005	/*
1006	 * Scan period doesn't matter because when all the sensors are
1007	 * deactivated the device is in sleep mode.
1008	 */
1009	ret = regmap_write(data->regmap, SX9500_REG_PROX_CTRL0, 0);
1010
1011out:
1012	mutex_unlock(&data->mutex);
1013	return ret;
1014}
1015
1016static int sx9500_resume(struct device *dev)
1017{
1018	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
1019	struct sx9500_data *data = iio_priv(indio_dev);
1020	int ret;
1021
1022	mutex_lock(&data->mutex);
1023	ret = regmap_write(data->regmap, SX9500_REG_PROX_CTRL0,
1024			   data->suspend_ctrl0);
1025	mutex_unlock(&data->mutex);
1026
1027	return ret;
1028}
1029
1030static DEFINE_SIMPLE_DEV_PM_OPS(sx9500_pm_ops, sx9500_suspend, sx9500_resume);
1031
1032static const struct acpi_device_id sx9500_acpi_match[] = {
1033	{"SSX9500", 0},
1034	{"SASX9500", 0},
1035	{ },
1036};
1037MODULE_DEVICE_TABLE(acpi, sx9500_acpi_match);
1038
1039static const struct of_device_id sx9500_of_match[] = {
1040	{ .compatible = "semtech,sx9500", },
1041	{ }
1042};
1043MODULE_DEVICE_TABLE(of, sx9500_of_match);
1044
1045static const struct i2c_device_id sx9500_id[] = {
1046	{"sx9500", 0},
1047	{ },
1048};
1049MODULE_DEVICE_TABLE(i2c, sx9500_id);
1050
1051static struct i2c_driver sx9500_driver = {
1052	.driver = {
1053		.name	= SX9500_DRIVER_NAME,
1054		.acpi_match_table = sx9500_acpi_match,
1055		.of_match_table = sx9500_of_match,
1056		.pm = pm_sleep_ptr(&sx9500_pm_ops),
1057	},
1058	.probe		= sx9500_probe,
1059	.remove		= sx9500_remove,
1060	.id_table	= sx9500_id,
1061};
1062module_i2c_driver(sx9500_driver);
1063
1064MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
1065MODULE_DESCRIPTION("Driver for Semtech SX9500 proximity sensor");
1066MODULE_LICENSE("GPL v2");
1067