xref: /openbmc/linux/drivers/iio/proximity/sx9310.c (revision 70a59dd8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2018 Google LLC.
4  *
5  * Driver for Semtech's SX9310/SX9311 capacitive proximity/button solution.
6  * Based on SX9500 driver and Semtech driver using the input framework
7  * <https://my.syncplicity.com/share/teouwsim8niiaud/
8  *          linux-driver-SX9310_NoSmartHSensing>.
9  * Reworked in April 2019 by Evan Green <evgreen@chromium.org>
10  * and in January 2020 by Daniel Campello <campello@chromium.org>.
11  */
12 
13 #include <linux/acpi.h>
14 #include <linux/bitfield.h>
15 #include <linux/delay.h>
16 #include <linux/i2c.h>
17 #include <linux/irq.h>
18 #include <linux/kernel.h>
19 #include <linux/mod_devicetable.h>
20 #include <linux/module.h>
21 #include <linux/pm.h>
22 #include <linux/regmap.h>
23 #include <linux/regulator/consumer.h>
24 #include <linux/slab.h>
25 
26 #include <linux/iio/buffer.h>
27 #include <linux/iio/events.h>
28 #include <linux/iio/iio.h>
29 #include <linux/iio/sysfs.h>
30 #include <linux/iio/trigger.h>
31 #include <linux/iio/triggered_buffer.h>
32 #include <linux/iio/trigger_consumer.h>
33 
34 /* Register definitions. */
35 #define SX9310_REG_IRQ_SRC				0x00
36 #define SX9310_REG_STAT0				0x01
37 #define SX9310_REG_STAT1				0x02
38 #define SX9310_REG_STAT1_COMPSTAT_MASK			GENMASK(3, 0)
39 #define SX9310_REG_IRQ_MSK				0x03
40 #define   SX9310_CONVDONE_IRQ				BIT(3)
41 #define   SX9310_FAR_IRQ				BIT(5)
42 #define   SX9310_CLOSE_IRQ				BIT(6)
43 #define SX9310_REG_IRQ_FUNC				0x04
44 
45 #define SX9310_REG_PROX_CTRL0				0x10
46 #define   SX9310_REG_PROX_CTRL0_SENSOREN_MASK		GENMASK(3, 0)
47 #define   SX9310_REG_PROX_CTRL0_SCANPERIOD_MASK		GENMASK(7, 4)
48 #define   SX9310_REG_PROX_CTRL0_SCANPERIOD_15MS		0x01
49 #define SX9310_REG_PROX_CTRL1				0x11
50 #define SX9310_REG_PROX_CTRL2				0x12
51 #define   SX9310_REG_PROX_CTRL2_COMBMODE_CS1_CS2	(0x02 << 6)
52 #define   SX9310_REG_PROX_CTRL2_SHIELDEN_DYNAMIC	(0x01 << 2)
53 #define SX9310_REG_PROX_CTRL3				0x13
54 #define   SX9310_REG_PROX_CTRL3_GAIN0_X8		(0x03 << 2)
55 #define   SX9310_REG_PROX_CTRL3_GAIN12_X4		0x02
56 #define SX9310_REG_PROX_CTRL4				0x14
57 #define   SX9310_REG_PROX_CTRL4_RESOLUTION_FINEST	0x07
58 #define SX9310_REG_PROX_CTRL5				0x15
59 #define   SX9310_REG_PROX_CTRL5_RANGE_SMALL		(0x03 << 6)
60 #define   SX9310_REG_PROX_CTRL5_STARTUPSENS_CS1		(0x01 << 2)
61 #define   SX9310_REG_PROX_CTRL5_RAWFILT_1P25		0x02
62 #define SX9310_REG_PROX_CTRL6				0x16
63 #define   SX9310_REG_PROX_CTRL6_AVGTHRESH_DEFAULT	0x20
64 #define SX9310_REG_PROX_CTRL7				0x17
65 #define   SX9310_REG_PROX_CTRL7_AVGNEGFILT_2		(0x01 << 3)
66 #define   SX9310_REG_PROX_CTRL7_AVGPOSFILT_512		0x05
67 #define SX9310_REG_PROX_CTRL8				0x18
68 #define SX9310_REG_PROX_CTRL9				0x19
69 #define   SX9310_REG_PROX_CTRL8_9_PTHRESH_28		(0x08 << 3)
70 #define   SX9310_REG_PROX_CTRL8_9_PTHRESH_96		(0x11 << 3)
71 #define   SX9310_REG_PROX_CTRL8_9_BODYTHRESH_900	0x03
72 #define   SX9310_REG_PROX_CTRL8_9_BODYTHRESH_1500	0x05
73 #define SX9310_REG_PROX_CTRL10				0x1a
74 #define   SX9310_REG_PROX_CTRL10_HYST_6PCT		(0x01 << 4)
75 #define   SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_2		0x01
76 #define SX9310_REG_PROX_CTRL11				0x1b
77 #define SX9310_REG_PROX_CTRL12				0x1c
78 #define SX9310_REG_PROX_CTRL13				0x1d
79 #define SX9310_REG_PROX_CTRL14				0x1e
80 #define SX9310_REG_PROX_CTRL15				0x1f
81 #define SX9310_REG_PROX_CTRL16				0x20
82 #define SX9310_REG_PROX_CTRL17				0x21
83 #define SX9310_REG_PROX_CTRL18				0x22
84 #define SX9310_REG_PROX_CTRL19				0x23
85 #define SX9310_REG_SAR_CTRL0				0x2a
86 #define   SX9310_REG_SAR_CTRL0_SARDEB_4_SAMPLES		(0x02 << 5)
87 #define   SX9310_REG_SAR_CTRL0_SARHYST_8		(0x02 << 3)
88 #define SX9310_REG_SAR_CTRL1				0x2b
89 /* Each increment of the slope register is 0.0078125. */
90 #define   SX9310_REG_SAR_CTRL1_SLOPE(_hnslope)		(_hnslope / 78125)
91 #define SX9310_REG_SAR_CTRL2				0x2c
92 #define   SX9310_REG_SAR_CTRL2_SAROFFSET_DEFAULT	0x3c
93 
94 #define SX9310_REG_SENSOR_SEL				0x30
95 #define SX9310_REG_USE_MSB				0x31
96 #define SX9310_REG_USE_LSB				0x32
97 #define SX9310_REG_AVG_MSB				0x33
98 #define SX9310_REG_AVG_LSB				0x34
99 #define SX9310_REG_DIFF_MSB				0x35
100 #define SX9310_REG_DIFF_LSB				0x36
101 #define SX9310_REG_OFFSET_MSB				0x37
102 #define SX9310_REG_OFFSET_LSB				0x38
103 #define SX9310_REG_SAR_MSB				0x39
104 #define SX9310_REG_SAR_LSB				0x3a
105 #define SX9310_REG_I2C_ADDR				0x40
106 #define SX9310_REG_PAUSE				0x41
107 #define SX9310_REG_WHOAMI				0x42
108 #define   SX9310_WHOAMI_VALUE				0x01
109 #define   SX9311_WHOAMI_VALUE				0x02
110 #define SX9310_REG_RESET				0x7f
111 #define   SX9310_SOFT_RESET				0xde
112 
113 
114 /* 4 hardware channels, as defined in STAT0: COMB, CS2, CS1 and CS0. */
115 #define SX9310_NUM_CHANNELS				4
116 static_assert(SX9310_NUM_CHANNELS < BITS_PER_LONG);
117 
118 struct sx9310_data {
119 	/* Serialize access to registers and channel configuration */
120 	struct mutex mutex;
121 	struct i2c_client *client;
122 	struct iio_trigger *trig;
123 	struct regmap *regmap;
124 	struct regulator_bulk_data supplies[2];
125 	/*
126 	 * Last reading of the proximity status for each channel.
127 	 * We only send an event to user space when this changes.
128 	 */
129 	unsigned long chan_prox_stat;
130 	bool trigger_enabled;
131 	/* Ensure correct alignment of timestamp when present. */
132 	struct {
133 		__be16 channels[SX9310_NUM_CHANNELS];
134 		s64 ts __aligned(8);
135 	} buffer;
136 	/* Remember enabled channels and sample rate during suspend. */
137 	unsigned int suspend_ctrl0;
138 	struct completion completion;
139 	unsigned long chan_read;
140 	unsigned long chan_event;
141 	unsigned int whoami;
142 };
143 
144 static const struct iio_event_spec sx9310_events[] = {
145 	{
146 		.type = IIO_EV_TYPE_THRESH,
147 		.dir = IIO_EV_DIR_EITHER,
148 		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
149 	},
150 };
151 
152 #define SX9310_NAMED_CHANNEL(idx, name)					 \
153 	{								 \
154 		.type = IIO_PROXIMITY,					 \
155 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		 \
156 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
157 		.indexed = 1,						 \
158 		.channel = idx,						 \
159 		.extend_name = name,					 \
160 		.address = SX9310_REG_DIFF_MSB,				 \
161 		.event_spec = sx9310_events,				 \
162 		.num_event_specs = ARRAY_SIZE(sx9310_events),		 \
163 		.scan_index = idx,					 \
164 		.scan_type = {						 \
165 			.sign = 's',					 \
166 			.realbits = 12,					 \
167 			.storagebits = 16,				 \
168 			.endianness = IIO_BE,				 \
169 		},							 \
170 	}
171 #define SX9310_CHANNEL(idx) SX9310_NAMED_CHANNEL(idx, NULL)
172 
173 static const struct iio_chan_spec sx9310_channels[] = {
174 	SX9310_CHANNEL(0),			/* CS0 */
175 	SX9310_CHANNEL(1),			/* CS1 */
176 	SX9310_CHANNEL(2),			/* CS2 */
177 	SX9310_NAMED_CHANNEL(3, "comb"),	/* COMB */
178 
179 	IIO_CHAN_SOFT_TIMESTAMP(4),
180 };
181 
182 /*
183  * Each entry contains the integer part (val) and the fractional part, in micro
184  * seconds. It conforms to the IIO output IIO_VAL_INT_PLUS_MICRO.
185  */
186 static const struct {
187 	int val;
188 	int val2;
189 } sx9310_samp_freq_table[] = {
190 	{ 500, 0 }, /* 0000: Min (no idle time) */
191 	{ 66, 666666 }, /* 0001: 15 ms */
192 	{ 33, 333333 }, /* 0010: 30 ms (Typ.) */
193 	{ 22, 222222 }, /* 0011: 45 ms */
194 	{ 16, 666666 }, /* 0100: 60 ms */
195 	{ 11, 111111 }, /* 0101: 90 ms */
196 	{ 8, 333333 }, /* 0110: 120 ms */
197 	{ 5, 0 }, /* 0111: 200 ms */
198 	{ 2, 500000 }, /* 1000: 400 ms */
199 	{ 1, 666666 }, /* 1001: 600 ms */
200 	{ 1, 250000 }, /* 1010: 800 ms */
201 	{ 1, 0 }, /* 1011: 1 s */
202 	{ 0, 500000 }, /* 1100: 2 s */
203 	{ 0, 333333 }, /* 1101: 3 s */
204 	{ 0, 250000 }, /* 1110: 4 s */
205 	{ 0, 200000 }, /* 1111: 5 s */
206 };
207 static const unsigned int sx9310_scan_period_table[] = {
208 	2,   15,  30,  45,   60,   90,	 120,  200,
209 	400, 600, 800, 1000, 2000, 3000, 4000, 5000,
210 };
211 
212 static ssize_t sx9310_show_samp_freq_avail(struct device *dev,
213 					   struct device_attribute *attr,
214 					   char *buf)
215 {
216 	size_t len = 0;
217 	int i;
218 
219 	for (i = 0; i < ARRAY_SIZE(sx9310_samp_freq_table); i++)
220 		len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%d ",
221 				 sx9310_samp_freq_table[i].val,
222 				 sx9310_samp_freq_table[i].val2);
223 	buf[len - 1] = '\n';
224 	return len;
225 }
226 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(sx9310_show_samp_freq_avail);
227 
228 static const struct regmap_range sx9310_writable_reg_ranges[] = {
229 	regmap_reg_range(SX9310_REG_IRQ_MSK, SX9310_REG_IRQ_FUNC),
230 	regmap_reg_range(SX9310_REG_PROX_CTRL0, SX9310_REG_PROX_CTRL19),
231 	regmap_reg_range(SX9310_REG_SAR_CTRL0, SX9310_REG_SAR_CTRL2),
232 	regmap_reg_range(SX9310_REG_SENSOR_SEL, SX9310_REG_SENSOR_SEL),
233 	regmap_reg_range(SX9310_REG_OFFSET_MSB, SX9310_REG_OFFSET_LSB),
234 	regmap_reg_range(SX9310_REG_PAUSE, SX9310_REG_PAUSE),
235 	regmap_reg_range(SX9310_REG_RESET, SX9310_REG_RESET),
236 };
237 
238 static const struct regmap_access_table sx9310_writeable_regs = {
239 	.yes_ranges = sx9310_writable_reg_ranges,
240 	.n_yes_ranges = ARRAY_SIZE(sx9310_writable_reg_ranges),
241 };
242 
243 static const struct regmap_range sx9310_readable_reg_ranges[] = {
244 	regmap_reg_range(SX9310_REG_IRQ_SRC, SX9310_REG_IRQ_FUNC),
245 	regmap_reg_range(SX9310_REG_PROX_CTRL0, SX9310_REG_PROX_CTRL19),
246 	regmap_reg_range(SX9310_REG_SAR_CTRL0, SX9310_REG_SAR_CTRL2),
247 	regmap_reg_range(SX9310_REG_SENSOR_SEL, SX9310_REG_SAR_LSB),
248 	regmap_reg_range(SX9310_REG_I2C_ADDR, SX9310_REG_WHOAMI),
249 	regmap_reg_range(SX9310_REG_RESET, SX9310_REG_RESET),
250 };
251 
252 static const struct regmap_access_table sx9310_readable_regs = {
253 	.yes_ranges = sx9310_readable_reg_ranges,
254 	.n_yes_ranges = ARRAY_SIZE(sx9310_readable_reg_ranges),
255 };
256 
257 static const struct regmap_range sx9310_volatile_reg_ranges[] = {
258 	regmap_reg_range(SX9310_REG_IRQ_SRC, SX9310_REG_STAT1),
259 	regmap_reg_range(SX9310_REG_USE_MSB, SX9310_REG_DIFF_LSB),
260 	regmap_reg_range(SX9310_REG_SAR_MSB, SX9310_REG_SAR_LSB),
261 	regmap_reg_range(SX9310_REG_RESET, SX9310_REG_RESET),
262 };
263 
264 static const struct regmap_access_table sx9310_volatile_regs = {
265 	.yes_ranges = sx9310_volatile_reg_ranges,
266 	.n_yes_ranges = ARRAY_SIZE(sx9310_volatile_reg_ranges),
267 };
268 
269 static const struct regmap_config sx9310_regmap_config = {
270 	.reg_bits = 8,
271 	.val_bits = 8,
272 
273 	.max_register = SX9310_REG_RESET,
274 	.cache_type = REGCACHE_RBTREE,
275 
276 	.wr_table = &sx9310_writeable_regs,
277 	.rd_table = &sx9310_readable_regs,
278 	.volatile_table = &sx9310_volatile_regs,
279 };
280 
281 static int sx9310_update_chan_en(struct sx9310_data *data,
282 				 unsigned long chan_read,
283 				 unsigned long chan_event)
284 {
285 	int ret;
286 	unsigned long channels = chan_read | chan_event;
287 
288 	if ((data->chan_read | data->chan_event) != channels) {
289 		ret = regmap_update_bits(data->regmap, SX9310_REG_PROX_CTRL0,
290 					 SX9310_REG_PROX_CTRL0_SENSOREN_MASK,
291 					 channels);
292 		if (ret)
293 			return ret;
294 	}
295 	data->chan_read = chan_read;
296 	data->chan_event = chan_event;
297 	return 0;
298 }
299 
300 static int sx9310_get_read_channel(struct sx9310_data *data, int channel)
301 {
302 	return sx9310_update_chan_en(data, data->chan_read | BIT(channel),
303 				     data->chan_event);
304 }
305 
306 static int sx9310_put_read_channel(struct sx9310_data *data, int channel)
307 {
308 	return sx9310_update_chan_en(data, data->chan_read & ~BIT(channel),
309 				     data->chan_event);
310 }
311 
312 static int sx9310_get_event_channel(struct sx9310_data *data, int channel)
313 {
314 	return sx9310_update_chan_en(data, data->chan_read,
315 				     data->chan_event | BIT(channel));
316 }
317 
318 static int sx9310_put_event_channel(struct sx9310_data *data, int channel)
319 {
320 	return sx9310_update_chan_en(data, data->chan_read,
321 				     data->chan_event & ~BIT(channel));
322 }
323 
324 static int sx9310_enable_irq(struct sx9310_data *data, unsigned int irq)
325 {
326 	if (!data->client->irq)
327 		return 0;
328 	return regmap_update_bits(data->regmap, SX9310_REG_IRQ_MSK, irq, irq);
329 }
330 
331 static int sx9310_disable_irq(struct sx9310_data *data, unsigned int irq)
332 {
333 	if (!data->client->irq)
334 		return 0;
335 	return regmap_update_bits(data->regmap, SX9310_REG_IRQ_MSK, irq, 0);
336 }
337 
338 static int sx9310_read_prox_data(struct sx9310_data *data,
339 				 const struct iio_chan_spec *chan, __be16 *val)
340 {
341 	int ret;
342 
343 	ret = regmap_write(data->regmap, SX9310_REG_SENSOR_SEL, chan->channel);
344 	if (ret)
345 		return ret;
346 
347 	return regmap_bulk_read(data->regmap, chan->address, val, sizeof(*val));
348 }
349 
350 /*
351  * If we have no interrupt support, we have to wait for a scan period
352  * after enabling a channel to get a result.
353  */
354 static int sx9310_wait_for_sample(struct sx9310_data *data)
355 {
356 	int ret;
357 	unsigned int val;
358 
359 	ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0, &val);
360 	if (ret)
361 		return ret;
362 
363 	val = FIELD_GET(SX9310_REG_PROX_CTRL0_SCANPERIOD_MASK, val);
364 
365 	msleep(sx9310_scan_period_table[val]);
366 
367 	return 0;
368 }
369 
370 static int sx9310_read_proximity(struct sx9310_data *data,
371 				 const struct iio_chan_spec *chan, int *val)
372 {
373 	int ret;
374 	__be16 rawval;
375 
376 	mutex_lock(&data->mutex);
377 
378 	ret = sx9310_get_read_channel(data, chan->channel);
379 	if (ret)
380 		goto out;
381 
382 	ret = sx9310_enable_irq(data, SX9310_CONVDONE_IRQ);
383 	if (ret)
384 		goto out_put_channel;
385 
386 	mutex_unlock(&data->mutex);
387 
388 	if (data->client->irq) {
389 		ret = wait_for_completion_interruptible(&data->completion);
390 		reinit_completion(&data->completion);
391 	} else {
392 		ret = sx9310_wait_for_sample(data);
393 	}
394 
395 	mutex_lock(&data->mutex);
396 
397 	if (ret)
398 		goto out_disable_irq;
399 
400 	ret = sx9310_read_prox_data(data, chan, &rawval);
401 	if (ret)
402 		goto out_disable_irq;
403 
404 	*val = sign_extend32(be16_to_cpu(rawval),
405 			     chan->address == SX9310_REG_DIFF_MSB ? 11 : 15);
406 
407 	ret = sx9310_disable_irq(data, SX9310_CONVDONE_IRQ);
408 	if (ret)
409 		goto out_put_channel;
410 
411 	ret = sx9310_put_read_channel(data, chan->channel);
412 	if (ret)
413 		goto out;
414 
415 	mutex_unlock(&data->mutex);
416 
417 	return IIO_VAL_INT;
418 
419 out_disable_irq:
420 	sx9310_disable_irq(data, SX9310_CONVDONE_IRQ);
421 out_put_channel:
422 	sx9310_put_read_channel(data, chan->channel);
423 out:
424 	mutex_unlock(&data->mutex);
425 
426 	return ret;
427 }
428 
429 static int sx9310_read_samp_freq(struct sx9310_data *data, int *val, int *val2)
430 {
431 	unsigned int regval;
432 	int ret;
433 
434 	ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0, &regval);
435 	if (ret)
436 		return ret;
437 
438 	regval = FIELD_GET(SX9310_REG_PROX_CTRL0_SCANPERIOD_MASK, regval);
439 	*val = sx9310_samp_freq_table[regval].val;
440 	*val2 = sx9310_samp_freq_table[regval].val2;
441 
442 	return IIO_VAL_INT_PLUS_MICRO;
443 }
444 
445 static int sx9310_read_raw(struct iio_dev *indio_dev,
446 			   const struct iio_chan_spec *chan, int *val,
447 			   int *val2, long mask)
448 {
449 	struct sx9310_data *data = iio_priv(indio_dev);
450 	int ret;
451 
452 	if (chan->type != IIO_PROXIMITY)
453 		return -EINVAL;
454 
455 	switch (mask) {
456 	case IIO_CHAN_INFO_RAW:
457 		ret = iio_device_claim_direct_mode(indio_dev);
458 		if (ret)
459 			return ret;
460 
461 		ret = sx9310_read_proximity(data, chan, val);
462 		iio_device_release_direct_mode(indio_dev);
463 		return ret;
464 	case IIO_CHAN_INFO_SAMP_FREQ:
465 		return sx9310_read_samp_freq(data, val, val2);
466 	default:
467 		return -EINVAL;
468 	}
469 }
470 
471 static int sx9310_set_samp_freq(struct sx9310_data *data, int val, int val2)
472 {
473 	int i, ret;
474 
475 	for (i = 0; i < ARRAY_SIZE(sx9310_samp_freq_table); i++)
476 		if (val == sx9310_samp_freq_table[i].val &&
477 		    val2 == sx9310_samp_freq_table[i].val2)
478 			break;
479 
480 	if (i == ARRAY_SIZE(sx9310_samp_freq_table))
481 		return -EINVAL;
482 
483 	mutex_lock(&data->mutex);
484 
485 	ret = regmap_update_bits(
486 		data->regmap, SX9310_REG_PROX_CTRL0,
487 		SX9310_REG_PROX_CTRL0_SCANPERIOD_MASK,
488 		FIELD_PREP(SX9310_REG_PROX_CTRL0_SCANPERIOD_MASK, i));
489 
490 	mutex_unlock(&data->mutex);
491 
492 	return ret;
493 }
494 
495 static int sx9310_write_raw(struct iio_dev *indio_dev,
496 			    const struct iio_chan_spec *chan, int val, int val2,
497 			    long mask)
498 {
499 	struct sx9310_data *data = iio_priv(indio_dev);
500 
501 	if (chan->type != IIO_PROXIMITY)
502 		return -EINVAL;
503 
504 	if (mask != IIO_CHAN_INFO_SAMP_FREQ)
505 		return -EINVAL;
506 
507 	return sx9310_set_samp_freq(data, val, val2);
508 }
509 
510 static irqreturn_t sx9310_irq_handler(int irq, void *private)
511 {
512 	struct iio_dev *indio_dev = private;
513 	struct sx9310_data *data = iio_priv(indio_dev);
514 
515 	if (data->trigger_enabled)
516 		iio_trigger_poll(data->trig);
517 
518 	/*
519 	 * Even if no event is enabled, we need to wake the thread to clear the
520 	 * interrupt state by reading SX9310_REG_IRQ_SRC.
521 	 * It is not possible to do that here because regmap_read takes a mutex.
522 	 */
523 	return IRQ_WAKE_THREAD;
524 }
525 
526 static void sx9310_push_events(struct iio_dev *indio_dev)
527 {
528 	int ret;
529 	unsigned int val, chan;
530 	struct sx9310_data *data = iio_priv(indio_dev);
531 	s64 timestamp = iio_get_time_ns(indio_dev);
532 	unsigned long prox_changed;
533 
534 	/* Read proximity state on all channels */
535 	ret = regmap_read(data->regmap, SX9310_REG_STAT0, &val);
536 	if (ret) {
537 		dev_err(&data->client->dev, "i2c transfer error in irq\n");
538 		return;
539 	}
540 
541 	/*
542 	 * Only iterate over channels with changes on proximity status that have
543 	 * events enabled.
544 	 */
545 	prox_changed = (data->chan_prox_stat ^ val) & data->chan_event;
546 
547 	for_each_set_bit(chan, &prox_changed, SX9310_NUM_CHANNELS) {
548 		int dir;
549 		u64 ev;
550 
551 		dir = (val & BIT(chan)) ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
552 		ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan,
553 					  IIO_EV_TYPE_THRESH, dir);
554 
555 		iio_push_event(indio_dev, ev, timestamp);
556 	}
557 	data->chan_prox_stat = val;
558 }
559 
560 static irqreturn_t sx9310_irq_thread_handler(int irq, void *private)
561 {
562 	struct iio_dev *indio_dev = private;
563 	struct sx9310_data *data = iio_priv(indio_dev);
564 	int ret;
565 	unsigned int val;
566 
567 	mutex_lock(&data->mutex);
568 
569 	ret = regmap_read(data->regmap, SX9310_REG_IRQ_SRC, &val);
570 	if (ret) {
571 		dev_err(&data->client->dev, "i2c transfer error in irq\n");
572 		goto out;
573 	}
574 
575 	if (val & (SX9310_FAR_IRQ | SX9310_CLOSE_IRQ))
576 		sx9310_push_events(indio_dev);
577 
578 	if (val & SX9310_CONVDONE_IRQ)
579 		complete(&data->completion);
580 
581 out:
582 	mutex_unlock(&data->mutex);
583 
584 	return IRQ_HANDLED;
585 }
586 
587 static int sx9310_read_event_config(struct iio_dev *indio_dev,
588 				    const struct iio_chan_spec *chan,
589 				    enum iio_event_type type,
590 				    enum iio_event_direction dir)
591 {
592 	struct sx9310_data *data = iio_priv(indio_dev);
593 
594 	return !!(data->chan_event & BIT(chan->channel));
595 }
596 
597 static int sx9310_write_event_config(struct iio_dev *indio_dev,
598 				     const struct iio_chan_spec *chan,
599 				     enum iio_event_type type,
600 				     enum iio_event_direction dir, int state)
601 {
602 	struct sx9310_data *data = iio_priv(indio_dev);
603 	unsigned int eventirq = SX9310_FAR_IRQ | SX9310_CLOSE_IRQ;
604 	int ret;
605 
606 	/* If the state hasn't changed, there's nothing to do. */
607 	if (!!(data->chan_event & BIT(chan->channel)) == state)
608 		return 0;
609 
610 	mutex_lock(&data->mutex);
611 	if (state) {
612 		ret = sx9310_get_event_channel(data, chan->channel);
613 		if (ret)
614 			goto out_unlock;
615 		if (!(data->chan_event & ~BIT(chan->channel))) {
616 			ret = sx9310_enable_irq(data, eventirq);
617 			if (ret)
618 				sx9310_put_event_channel(data, chan->channel);
619 		}
620 	} else {
621 		ret = sx9310_put_event_channel(data, chan->channel);
622 		if (ret)
623 			goto out_unlock;
624 		if (!data->chan_event) {
625 			ret = sx9310_disable_irq(data, eventirq);
626 			if (ret)
627 				sx9310_get_event_channel(data, chan->channel);
628 		}
629 	}
630 
631 out_unlock:
632 	mutex_unlock(&data->mutex);
633 	return ret;
634 }
635 
636 static struct attribute *sx9310_attributes[] = {
637 	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
638 	NULL
639 };
640 
641 static const struct attribute_group sx9310_attribute_group = {
642 	.attrs = sx9310_attributes,
643 };
644 
645 static const struct iio_info sx9310_info = {
646 	.attrs = &sx9310_attribute_group,
647 	.read_raw = sx9310_read_raw,
648 	.write_raw = sx9310_write_raw,
649 	.read_event_config = sx9310_read_event_config,
650 	.write_event_config = sx9310_write_event_config,
651 };
652 
653 static int sx9310_set_trigger_state(struct iio_trigger *trig, bool state)
654 {
655 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
656 	struct sx9310_data *data = iio_priv(indio_dev);
657 	int ret = 0;
658 
659 	mutex_lock(&data->mutex);
660 
661 	if (state)
662 		ret = sx9310_enable_irq(data, SX9310_CONVDONE_IRQ);
663 	else if (!data->chan_read)
664 		ret = sx9310_disable_irq(data, SX9310_CONVDONE_IRQ);
665 	if (ret)
666 		goto out;
667 
668 	data->trigger_enabled = state;
669 
670 out:
671 	mutex_unlock(&data->mutex);
672 
673 	return ret;
674 }
675 
676 static const struct iio_trigger_ops sx9310_trigger_ops = {
677 	.set_trigger_state = sx9310_set_trigger_state,
678 };
679 
680 static irqreturn_t sx9310_trigger_handler(int irq, void *private)
681 {
682 	struct iio_poll_func *pf = private;
683 	struct iio_dev *indio_dev = pf->indio_dev;
684 	struct sx9310_data *data = iio_priv(indio_dev);
685 	__be16 val;
686 	int bit, ret, i = 0;
687 
688 	mutex_lock(&data->mutex);
689 
690 	for_each_set_bit(bit, indio_dev->active_scan_mask,
691 			 indio_dev->masklength) {
692 		ret = sx9310_read_prox_data(data, &indio_dev->channels[bit],
693 					    &val);
694 		if (ret)
695 			goto out;
696 
697 		data->buffer.channels[i++] = val;
698 	}
699 
700 	iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer,
701 					   pf->timestamp);
702 
703 out:
704 	mutex_unlock(&data->mutex);
705 
706 	iio_trigger_notify_done(indio_dev->trig);
707 
708 	return IRQ_HANDLED;
709 }
710 
711 static int sx9310_buffer_preenable(struct iio_dev *indio_dev)
712 {
713 	struct sx9310_data *data = iio_priv(indio_dev);
714 	unsigned long channels = 0;
715 	int bit, ret;
716 
717 	mutex_lock(&data->mutex);
718 	for_each_set_bit(bit, indio_dev->active_scan_mask,
719 			 indio_dev->masklength)
720 		__set_bit(indio_dev->channels[bit].channel, &channels);
721 
722 	ret = sx9310_update_chan_en(data, channels, data->chan_event);
723 	mutex_unlock(&data->mutex);
724 	return ret;
725 }
726 
727 static int sx9310_buffer_postdisable(struct iio_dev *indio_dev)
728 {
729 	struct sx9310_data *data = iio_priv(indio_dev);
730 	int ret;
731 
732 	mutex_lock(&data->mutex);
733 	ret = sx9310_update_chan_en(data, 0, data->chan_event);
734 	mutex_unlock(&data->mutex);
735 	return ret;
736 }
737 
738 static const struct iio_buffer_setup_ops sx9310_buffer_setup_ops = {
739 	.preenable = sx9310_buffer_preenable,
740 	.postdisable = sx9310_buffer_postdisable,
741 };
742 
743 struct sx9310_reg_default {
744 	u8 reg;
745 	u8 def;
746 };
747 
748 static const struct sx9310_reg_default sx9310_default_regs[] = {
749 	{ SX9310_REG_IRQ_MSK, 0x00 },
750 	{ SX9310_REG_IRQ_FUNC, 0x00 },
751 	/*
752 	 * The lower 4 bits should not be set as it enable sensors measurements.
753 	 * Turning the detection on before the configuration values are set to
754 	 * good values can cause the device to return erroneous readings.
755 	 */
756 	{ SX9310_REG_PROX_CTRL0, SX9310_REG_PROX_CTRL0_SCANPERIOD_15MS },
757 	{ SX9310_REG_PROX_CTRL1, 0x00 },
758 	{ SX9310_REG_PROX_CTRL2, SX9310_REG_PROX_CTRL2_COMBMODE_CS1_CS2 |
759 				 SX9310_REG_PROX_CTRL2_SHIELDEN_DYNAMIC },
760 	{ SX9310_REG_PROX_CTRL3, SX9310_REG_PROX_CTRL3_GAIN0_X8 |
761 				 SX9310_REG_PROX_CTRL3_GAIN12_X4 },
762 	{ SX9310_REG_PROX_CTRL4, SX9310_REG_PROX_CTRL4_RESOLUTION_FINEST },
763 	{ SX9310_REG_PROX_CTRL5, SX9310_REG_PROX_CTRL5_RANGE_SMALL |
764 				 SX9310_REG_PROX_CTRL5_STARTUPSENS_CS1 |
765 				 SX9310_REG_PROX_CTRL5_RAWFILT_1P25 },
766 	{ SX9310_REG_PROX_CTRL6, SX9310_REG_PROX_CTRL6_AVGTHRESH_DEFAULT },
767 	{ SX9310_REG_PROX_CTRL7, SX9310_REG_PROX_CTRL7_AVGNEGFILT_2 |
768 				 SX9310_REG_PROX_CTRL7_AVGPOSFILT_512 },
769 	{ SX9310_REG_PROX_CTRL8, SX9310_REG_PROX_CTRL8_9_PTHRESH_96 |
770 				 SX9310_REG_PROX_CTRL8_9_BODYTHRESH_1500 },
771 	{ SX9310_REG_PROX_CTRL9, SX9310_REG_PROX_CTRL8_9_PTHRESH_28 |
772 				 SX9310_REG_PROX_CTRL8_9_BODYTHRESH_900 },
773 	{ SX9310_REG_PROX_CTRL10, SX9310_REG_PROX_CTRL10_HYST_6PCT |
774 				  SX9310_REG_PROX_CTRL10_FAR_DEBOUNCE_2 },
775 	{ SX9310_REG_PROX_CTRL11, 0x00 },
776 	{ SX9310_REG_PROX_CTRL12, 0x00 },
777 	{ SX9310_REG_PROX_CTRL13, 0x00 },
778 	{ SX9310_REG_PROX_CTRL14, 0x00 },
779 	{ SX9310_REG_PROX_CTRL15, 0x00 },
780 	{ SX9310_REG_PROX_CTRL16, 0x00 },
781 	{ SX9310_REG_PROX_CTRL17, 0x00 },
782 	{ SX9310_REG_PROX_CTRL18, 0x00 },
783 	{ SX9310_REG_PROX_CTRL19, 0x00 },
784 	{ SX9310_REG_SAR_CTRL0, SX9310_REG_SAR_CTRL0_SARDEB_4_SAMPLES |
785 				SX9310_REG_SAR_CTRL0_SARHYST_8 },
786 	{ SX9310_REG_SAR_CTRL1, SX9310_REG_SAR_CTRL1_SLOPE(10781250) },
787 	{ SX9310_REG_SAR_CTRL2, SX9310_REG_SAR_CTRL2_SAROFFSET_DEFAULT },
788 };
789 
790 /* Activate all channels and perform an initial compensation. */
791 static int sx9310_init_compensation(struct iio_dev *indio_dev)
792 {
793 	struct sx9310_data *data = iio_priv(indio_dev);
794 	int ret;
795 	unsigned int val;
796 	unsigned int ctrl0;
797 
798 	ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0, &ctrl0);
799 	if (ret)
800 		return ret;
801 
802 	/* run the compensation phase on all channels */
803 	ret = regmap_write(data->regmap, SX9310_REG_PROX_CTRL0,
804 			   ctrl0 | SX9310_REG_PROX_CTRL0_SENSOREN_MASK);
805 	if (ret)
806 		return ret;
807 
808 	ret = regmap_read_poll_timeout(data->regmap, SX9310_REG_STAT1, val,
809 				       !(val & SX9310_REG_STAT1_COMPSTAT_MASK),
810 				       20000, 2000000);
811 	if (ret) {
812 		if (ret == -ETIMEDOUT)
813 			dev_err(&data->client->dev,
814 				"initial compensation timed out: 0x%02x\n",
815 				val);
816 		return ret;
817 	}
818 
819 	regmap_write(data->regmap, SX9310_REG_PROX_CTRL0, ctrl0);
820 	return ret;
821 }
822 
823 static int sx9310_init_device(struct iio_dev *indio_dev)
824 {
825 	struct sx9310_data *data = iio_priv(indio_dev);
826 	const struct sx9310_reg_default *initval;
827 	int ret;
828 	unsigned int i, val;
829 
830 	ret = regmap_write(data->regmap, SX9310_REG_RESET, SX9310_SOFT_RESET);
831 	if (ret)
832 		return ret;
833 
834 	usleep_range(1000, 2000); /* power-up time is ~1ms. */
835 
836 	/* Clear reset interrupt state by reading SX9310_REG_IRQ_SRC. */
837 	ret = regmap_read(data->regmap, SX9310_REG_IRQ_SRC, &val);
838 	if (ret)
839 		return ret;
840 
841 	/* Program some sane defaults. */
842 	for (i = 0; i < ARRAY_SIZE(sx9310_default_regs); i++) {
843 		initval = &sx9310_default_regs[i];
844 		ret = regmap_write(data->regmap, initval->reg, initval->def);
845 		if (ret)
846 			return ret;
847 	}
848 
849 	return sx9310_init_compensation(indio_dev);
850 }
851 
852 static int sx9310_set_indio_dev_name(struct device *dev,
853 				     struct iio_dev *indio_dev,
854 				     unsigned int whoami)
855 {
856 	unsigned int long ddata;
857 
858 	ddata = (uintptr_t)device_get_match_data(dev);
859 	if (ddata != whoami) {
860 		dev_err(dev, "WHOAMI does not match device data: %u\n", whoami);
861 		return -ENODEV;
862 	}
863 
864 	switch (whoami) {
865 	case SX9310_WHOAMI_VALUE:
866 		indio_dev->name = "sx9310";
867 		break;
868 	case SX9311_WHOAMI_VALUE:
869 		indio_dev->name = "sx9311";
870 		break;
871 	default:
872 		dev_err(dev, "unexpected WHOAMI response: %u\n", whoami);
873 		return -ENODEV;
874 	}
875 
876 	return 0;
877 }
878 
879 static void sx9310_regulator_disable(void *_data)
880 {
881 	struct sx9310_data *data = _data;
882 
883 	regulator_bulk_disable(ARRAY_SIZE(data->supplies), data->supplies);
884 }
885 
886 static int sx9310_probe(struct i2c_client *client)
887 {
888 	int ret;
889 	struct device *dev = &client->dev;
890 	struct iio_dev *indio_dev;
891 	struct sx9310_data *data;
892 
893 	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
894 	if (!indio_dev)
895 		return -ENOMEM;
896 
897 	data = iio_priv(indio_dev);
898 	data->client = client;
899 	data->supplies[0].supply = "vdd";
900 	data->supplies[1].supply = "svdd";
901 	mutex_init(&data->mutex);
902 	init_completion(&data->completion);
903 
904 	data->regmap = devm_regmap_init_i2c(client, &sx9310_regmap_config);
905 	if (IS_ERR(data->regmap))
906 		return PTR_ERR(data->regmap);
907 
908 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(data->supplies),
909 				      data->supplies);
910 	if (ret)
911 		return ret;
912 
913 	ret = regulator_bulk_enable(ARRAY_SIZE(data->supplies), data->supplies);
914 	if (ret)
915 		return ret;
916 	/* Must wait for Tpor time after initial power up */
917 	usleep_range(1000, 1100);
918 
919 	ret = devm_add_action_or_reset(dev, sx9310_regulator_disable, data);
920 	if (ret)
921 		return ret;
922 
923 	ret = regmap_read(data->regmap, SX9310_REG_WHOAMI, &data->whoami);
924 	if (ret) {
925 		dev_err(dev, "error in reading WHOAMI register: %d", ret);
926 		return ret;
927 	}
928 
929 	ret = sx9310_set_indio_dev_name(dev, indio_dev, data->whoami);
930 	if (ret)
931 		return ret;
932 
933 	ACPI_COMPANION_SET(&indio_dev->dev, ACPI_COMPANION(dev));
934 	indio_dev->channels = sx9310_channels;
935 	indio_dev->num_channels = ARRAY_SIZE(sx9310_channels);
936 	indio_dev->info = &sx9310_info;
937 	indio_dev->modes = INDIO_DIRECT_MODE;
938 	i2c_set_clientdata(client, indio_dev);
939 
940 	ret = sx9310_init_device(indio_dev);
941 	if (ret)
942 		return ret;
943 
944 	if (client->irq) {
945 		ret = devm_request_threaded_irq(dev, client->irq,
946 						sx9310_irq_handler,
947 						sx9310_irq_thread_handler,
948 						IRQF_ONESHOT,
949 						"sx9310_event", indio_dev);
950 		if (ret)
951 			return ret;
952 
953 		data->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
954 						    indio_dev->name,
955 						    indio_dev->id);
956 		if (!data->trig)
957 			return -ENOMEM;
958 
959 		data->trig->dev.parent = dev;
960 		data->trig->ops = &sx9310_trigger_ops;
961 		iio_trigger_set_drvdata(data->trig, indio_dev);
962 
963 		ret = devm_iio_trigger_register(dev, data->trig);
964 		if (ret)
965 			return ret;
966 	}
967 
968 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
969 					      iio_pollfunc_store_time,
970 					      sx9310_trigger_handler,
971 					      &sx9310_buffer_setup_ops);
972 	if (ret)
973 		return ret;
974 
975 	return devm_iio_device_register(dev, indio_dev);
976 }
977 
978 static int __maybe_unused sx9310_suspend(struct device *dev)
979 {
980 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
981 	struct sx9310_data *data = iio_priv(indio_dev);
982 	u8 ctrl0;
983 	int ret;
984 
985 	disable_irq_nosync(data->client->irq);
986 
987 	mutex_lock(&data->mutex);
988 	ret = regmap_read(data->regmap, SX9310_REG_PROX_CTRL0,
989 			  &data->suspend_ctrl0);
990 	if (ret)
991 		goto out;
992 
993 	ctrl0 = data->suspend_ctrl0 & ~SX9310_REG_PROX_CTRL0_SENSOREN_MASK;
994 	ret = regmap_write(data->regmap, SX9310_REG_PROX_CTRL0, ctrl0);
995 	if (ret)
996 		goto out;
997 
998 	ret = regmap_write(data->regmap, SX9310_REG_PAUSE, 0);
999 
1000 out:
1001 	mutex_unlock(&data->mutex);
1002 	return ret;
1003 }
1004 
1005 static int __maybe_unused sx9310_resume(struct device *dev)
1006 {
1007 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
1008 	struct sx9310_data *data = iio_priv(indio_dev);
1009 	int ret;
1010 
1011 	mutex_lock(&data->mutex);
1012 	ret = regmap_write(data->regmap, SX9310_REG_PAUSE, 1);
1013 	if (ret)
1014 		goto out;
1015 
1016 	ret = regmap_write(data->regmap, SX9310_REG_PROX_CTRL0,
1017 			   data->suspend_ctrl0);
1018 
1019 out:
1020 	mutex_unlock(&data->mutex);
1021 	if (ret)
1022 		return ret;
1023 
1024 	enable_irq(data->client->irq);
1025 	return 0;
1026 }
1027 
1028 static const struct dev_pm_ops sx9310_pm_ops = {
1029 	SET_SYSTEM_SLEEP_PM_OPS(sx9310_suspend, sx9310_resume)
1030 };
1031 
1032 static const struct acpi_device_id sx9310_acpi_match[] = {
1033 	{ "STH9310", SX9310_WHOAMI_VALUE },
1034 	{ "STH9311", SX9311_WHOAMI_VALUE },
1035 	{}
1036 };
1037 MODULE_DEVICE_TABLE(acpi, sx9310_acpi_match);
1038 
1039 static const struct of_device_id sx9310_of_match[] = {
1040 	{ .compatible = "semtech,sx9310", (void *)SX9310_WHOAMI_VALUE },
1041 	{ .compatible = "semtech,sx9311", (void *)SX9311_WHOAMI_VALUE },
1042 	{}
1043 };
1044 MODULE_DEVICE_TABLE(of, sx9310_of_match);
1045 
1046 static const struct i2c_device_id sx9310_id[] = {
1047 	{ "sx9310", SX9310_WHOAMI_VALUE },
1048 	{ "sx9311", SX9311_WHOAMI_VALUE },
1049 	{}
1050 };
1051 MODULE_DEVICE_TABLE(i2c, sx9310_id);
1052 
1053 static struct i2c_driver sx9310_driver = {
1054 	.driver = {
1055 		.name	= "sx9310",
1056 		.acpi_match_table = sx9310_acpi_match,
1057 		.of_match_table = sx9310_of_match,
1058 		.pm = &sx9310_pm_ops,
1059 
1060 		/*
1061 		 * Lots of i2c transfers in probe + over 200 ms waiting in
1062 		 * sx9310_init_compensation() mean a slow probe; prefer async
1063 		 * so we don't delay boot if we're builtin to the kernel.
1064 		 */
1065 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1066 	},
1067 	.probe_new	= sx9310_probe,
1068 	.id_table	= sx9310_id,
1069 };
1070 module_i2c_driver(sx9310_driver);
1071 
1072 MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
1073 MODULE_AUTHOR("Daniel Campello <campello@chromium.org>");
1074 MODULE_DESCRIPTION("Driver for Semtech SX9310/SX9311 proximity sensor");
1075 MODULE_LICENSE("GPL v2");
1076