xref: /openbmc/linux/drivers/iio/proximity/sx9360.c (revision 0a4cad9c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2021 Google LLC.
4  *
5  * Driver for Semtech's SX9360 capacitive proximity/button solution.
6  * Based on SX9360 driver and copy of datasheet at:
7  * https://edit.wpgdadawant.com/uploads/news_file/program/2019/30184/tech_files/program_30184_suggest_other_file.pdf
8  */
9 
10 #include <linux/acpi.h>
11 #include <linux/bits.h>
12 #include <linux/bitfield.h>
13 #include <linux/delay.h>
14 #include <linux/i2c.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel.h>
17 #include <linux/log2.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/module.h>
20 #include <linux/pm.h>
21 #include <linux/property.h>
22 #include <linux/regmap.h>
23 
24 #include <linux/iio/iio.h>
25 
26 #include "sx_common.h"
27 
28 /* Nominal Oscillator Frequency. */
29 #define SX9360_FOSC_MHZ			4
30 #define SX9360_FOSC_HZ			(SX9360_FOSC_MHZ * 1000000)
31 
32 /* Register definitions. */
33 #define SX9360_REG_IRQ_SRC		SX_COMMON_REG_IRQ_SRC
34 #define SX9360_REG_STAT		0x01
35 #define SX9360_REG_STAT_COMPSTAT_MASK	GENMASK(2, 1)
36 #define SX9360_REG_IRQ_MSK		0x02
37 #define SX9360_CONVDONE_IRQ		BIT(0)
38 #define SX9360_FAR_IRQ			BIT(2)
39 #define SX9360_CLOSE_IRQ		BIT(3)
40 #define SX9360_REG_IRQ_CFG		0x03
41 
42 #define SX9360_REG_GNRL_CTRL0		0x10
43 #define SX9360_REG_GNRL_CTRL0_PHEN_MASK GENMASK(1, 0)
44 #define SX9360_REG_GNRL_CTRL1		0x11
45 #define SX9360_REG_GNRL_CTRL1_SCANPERIOD_MASK GENMASK(2, 0)
46 #define SX9360_REG_GNRL_CTRL2		0x12
47 #define SX9360_REG_GNRL_CTRL2_PERIOD_102MS	0x32
48 #define SX9360_REG_GNRL_REG_2_PERIOD_MS(_r)	\
49 	(((_r) * 8192) / (SX9360_FOSC_HZ / 1000))
50 #define SX9360_REG_GNRL_FREQ_2_REG(_f)  (((_f) * 8192) / SX9360_FOSC_HZ)
51 #define SX9360_REG_GNRL_REG_2_FREQ(_r)  (SX9360_FOSC_HZ / ((_r) * 8192))
52 
53 #define SX9360_REG_AFE_CTRL1		0x21
54 #define SX9360_REG_AFE_PARAM0_PHR	0x22
55 #define SX9360_REG_AFE_PARAM1_PHR	0x23
56 #define SX9360_REG_AFE_PARAM0_PHM	0x24
57 #define SX9360_REG_AFE_PARAM0_RSVD		0x08
58 #define SX9360_REG_AFE_PARAM0_RESOLUTION_MASK	GENMASK(2, 0)
59 #define SX9360_REG_AFE_PARAM0_RESOLUTION_128	0x02
60 #define SX9360_REG_AFE_PARAM1_PHM	0x25
61 #define SX9360_REG_AFE_PARAM1_AGAIN_PHM_6PF	0x40
62 #define SX9360_REG_AFE_PARAM1_FREQ_83_33HZ	0x06
63 
64 #define SX9360_REG_PROX_CTRL0_PHR	0x40
65 #define SX9360_REG_PROX_CTRL0_PHM	0x41
66 #define SX9360_REG_PROX_CTRL0_GAIN_MASK	GENMASK(5, 3)
67 #define SX9360_REG_PROX_CTRL0_GAIN_1		0x80
68 #define SX9360_REG_PROX_CTRL0_RAWFILT_MASK	GENMASK(2, 0)
69 #define SX9360_REG_PROX_CTRL0_RAWFILT_1P50	0x01
70 #define SX9360_REG_PROX_CTRL1		0x42
71 #define SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_MASK	GENMASK(5, 3)
72 #define SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_16K 0x20
73 #define SX9360_REG_PROX_CTRL2		0x43
74 #define SX9360_REG_PROX_CTRL2_AVGDEB_MASK	GENMASK(7, 6)
75 #define SX9360_REG_PROX_CTRL2_AVGDEB_2SAMPLES	0x40
76 #define SX9360_REG_PROX_CTRL2_AVGPOS_THRESH_16K	0x20
77 #define SX9360_REG_PROX_CTRL3		0x44
78 #define SX9360_REG_PROX_CTRL3_AVGNEG_FILT_MASK	GENMASK(5, 3)
79 #define SX9360_REG_PROX_CTRL3_AVGNEG_FILT_2	0x08
80 #define SX9360_REG_PROX_CTRL3_AVGPOS_FILT_MASK	GENMASK(2, 0)
81 #define SX9360_REG_PROX_CTRL3_AVGPOS_FILT_256	0x04
82 #define SX9360_REG_PROX_CTRL4		0x45
83 #define SX9360_REG_PROX_CTRL4_HYST_MASK			GENMASK(5, 4)
84 #define SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK	GENMASK(3, 2)
85 #define SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK		GENMASK(1, 0)
86 #define SX9360_REG_PROX_CTRL5		0x46
87 #define SX9360_REG_PROX_CTRL5_PROXTHRESH_32	0x08
88 
89 #define SX9360_REG_REF_CORR0		0x60
90 #define SX9360_REG_REF_CORR1		0x61
91 
92 #define SX9360_REG_USEFUL_PHR_MSB		0x90
93 #define SX9360_REG_USEFUL_PHR_LSB		0x91
94 
95 #define SX9360_REG_OFFSET_PMR_MSB		0x92
96 #define SX9360_REG_OFFSET_PMR_LSB		0x93
97 
98 #define SX9360_REG_USEFUL_PHM_MSB		0x94
99 #define SX9360_REG_USEFUL_PHM_LSB		0x95
100 
101 #define SX9360_REG_AVG_PHM_MSB		0x96
102 #define SX9360_REG_AVG_PHM_LSB		0x97
103 
104 #define SX9360_REG_DIFF_PHM_MSB		0x98
105 #define SX9360_REG_DIFF_PHM_LSB		0x99
106 
107 #define SX9360_REG_OFFSET_PHM_MSB		0x9a
108 #define SX9360_REG_OFFSET_PHM_LSB		0x9b
109 
110 #define SX9360_REG_USE_FILTER_MSB		0x9a
111 #define SX9360_REG_USE_FILTER_LSB		0x9b
112 
113 #define SX9360_REG_RESET		0xcf
114 /* Write this to REG_RESET to do a soft reset. */
115 #define SX9360_SOFT_RESET		0xde
116 
117 #define SX9360_REG_WHOAMI		0xfa
118 #define   SX9360_WHOAMI_VALUE				0x60
119 
120 #define SX9360_REG_REVISION		0xfe
121 
122 /* 2 channels, Phase Reference and Measurement. */
123 #define SX9360_NUM_CHANNELS		2
124 
125 static const struct iio_chan_spec sx9360_channels[] = {
126 	{
127 		.type = IIO_PROXIMITY,
128 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
129 				      BIT(IIO_CHAN_INFO_HARDWAREGAIN),
130 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
131 		.info_mask_separate_available =
132 			BIT(IIO_CHAN_INFO_HARDWAREGAIN),
133 		.info_mask_shared_by_all_available =
134 			BIT(IIO_CHAN_INFO_SAMP_FREQ),
135 		.indexed = 1,
136 		.address = SX9360_REG_USEFUL_PHR_MSB,
137 		.channel = 0,
138 		.scan_index = 0,
139 		.scan_type = {
140 			.sign = 's',
141 			.realbits = 12,
142 			.storagebits = 16,
143 			.endianness = IIO_BE,
144 		},
145 	},
146 	{
147 		.type = IIO_PROXIMITY,
148 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
149 				      BIT(IIO_CHAN_INFO_HARDWAREGAIN),
150 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
151 		.info_mask_separate_available =
152 			BIT(IIO_CHAN_INFO_HARDWAREGAIN),
153 		.info_mask_shared_by_all_available =
154 			BIT(IIO_CHAN_INFO_SAMP_FREQ),
155 		.indexed = 1,
156 		.address = SX9360_REG_USEFUL_PHM_MSB,
157 		.event_spec = sx_common_events,
158 		.num_event_specs = ARRAY_SIZE(sx_common_events),
159 		.channel = 1,
160 		.scan_index = 1,
161 		.scan_type = {
162 			.sign = 's',
163 			.realbits = 12,
164 			.storagebits = 16,
165 			.endianness = IIO_BE,
166 		},
167 	},
168 	IIO_CHAN_SOFT_TIMESTAMP(2),
169 };
170 
171 /*
172  * Each entry contains the integer part (val) and the fractional part, in micro
173  * seconds. It conforms to the IIO output IIO_VAL_INT_PLUS_MICRO.
174  *
175  * The frequency control register holds the period, with a ~2ms increment.
176  * Therefore the smallest frequency is 4MHz / (2047 * 8192),
177  * The fastest is 4MHz / 8192.
178  * The interval is not linear, but given there is 2047 possible value,
179  * Returns the fake increment of (Max-Min)/2047
180  */
181 static const struct {
182 	int val;
183 	int val2;
184 } sx9360_samp_freq_interval[] = {
185 	{ 0, 281250 },  /* 4MHz / (8192 * 2047) */
186 	{ 0, 281250 },
187 	{ 448, 281250 },  /* 4MHz / 8192 */
188 };
189 
190 static const struct regmap_range sx9360_writable_reg_ranges[] = {
191 	/*
192 	 * To set COMPSTAT for compensation, even if datasheet says register is
193 	 * RO.
194 	 */
195 	regmap_reg_range(SX9360_REG_STAT, SX9360_REG_IRQ_CFG),
196 	regmap_reg_range(SX9360_REG_GNRL_CTRL0, SX9360_REG_GNRL_CTRL2),
197 	regmap_reg_range(SX9360_REG_AFE_CTRL1, SX9360_REG_AFE_PARAM1_PHM),
198 	regmap_reg_range(SX9360_REG_PROX_CTRL0_PHR, SX9360_REG_PROX_CTRL5),
199 	regmap_reg_range(SX9360_REG_REF_CORR0, SX9360_REG_REF_CORR1),
200 	regmap_reg_range(SX9360_REG_OFFSET_PMR_MSB, SX9360_REG_OFFSET_PMR_LSB),
201 	regmap_reg_range(SX9360_REG_RESET, SX9360_REG_RESET),
202 };
203 
204 static const struct regmap_access_table sx9360_writeable_regs = {
205 	.yes_ranges = sx9360_writable_reg_ranges,
206 	.n_yes_ranges = ARRAY_SIZE(sx9360_writable_reg_ranges),
207 };
208 
209 /*
210  * All allocated registers are readable, so we just list unallocated
211  * ones.
212  */
213 static const struct regmap_range sx9360_non_readable_reg_ranges[] = {
214 	regmap_reg_range(SX9360_REG_IRQ_CFG + 1, SX9360_REG_GNRL_CTRL0 - 1),
215 	regmap_reg_range(SX9360_REG_GNRL_CTRL2 + 1, SX9360_REG_AFE_CTRL1 - 1),
216 	regmap_reg_range(SX9360_REG_AFE_PARAM1_PHM + 1,
217 			 SX9360_REG_PROX_CTRL0_PHR - 1),
218 	regmap_reg_range(SX9360_REG_PROX_CTRL5 + 1, SX9360_REG_REF_CORR0 - 1),
219 	regmap_reg_range(SX9360_REG_REF_CORR1 + 1,
220 			 SX9360_REG_USEFUL_PHR_MSB - 1),
221 	regmap_reg_range(SX9360_REG_USE_FILTER_LSB + 1, SX9360_REG_RESET - 1),
222 	regmap_reg_range(SX9360_REG_RESET + 1, SX9360_REG_WHOAMI - 1),
223 	regmap_reg_range(SX9360_REG_WHOAMI + 1, SX9360_REG_REVISION - 1),
224 };
225 
226 static const struct regmap_access_table sx9360_readable_regs = {
227 	.no_ranges = sx9360_non_readable_reg_ranges,
228 	.n_no_ranges = ARRAY_SIZE(sx9360_non_readable_reg_ranges),
229 };
230 
231 static const struct regmap_range sx9360_volatile_reg_ranges[] = {
232 	regmap_reg_range(SX9360_REG_IRQ_SRC, SX9360_REG_STAT),
233 	regmap_reg_range(SX9360_REG_USEFUL_PHR_MSB, SX9360_REG_USE_FILTER_LSB),
234 	regmap_reg_range(SX9360_REG_WHOAMI, SX9360_REG_WHOAMI),
235 	regmap_reg_range(SX9360_REG_REVISION, SX9360_REG_REVISION),
236 };
237 
238 static const struct regmap_access_table sx9360_volatile_regs = {
239 	.yes_ranges = sx9360_volatile_reg_ranges,
240 	.n_yes_ranges = ARRAY_SIZE(sx9360_volatile_reg_ranges),
241 };
242 
243 static const struct regmap_config sx9360_regmap_config = {
244 	.reg_bits = 8,
245 	.val_bits = 8,
246 
247 	.max_register = SX9360_REG_REVISION,
248 	.cache_type = REGCACHE_RBTREE,
249 
250 	.wr_table = &sx9360_writeable_regs,
251 	.rd_table = &sx9360_readable_regs,
252 	.volatile_table = &sx9360_volatile_regs,
253 };
254 
255 static int sx9360_read_prox_data(struct sx_common_data *data,
256 				 const struct iio_chan_spec *chan,
257 				 __be16 *val)
258 {
259 	return regmap_bulk_read(data->regmap, chan->address, val, sizeof(*val));
260 }
261 
262 /*
263  * If we have no interrupt support, we have to wait for a scan period
264  * after enabling a channel to get a result.
265  */
266 static int sx9360_wait_for_sample(struct sx_common_data *data)
267 {
268 	int ret;
269 	__be16 buf;
270 
271 	ret = regmap_bulk_read(data->regmap, SX9360_REG_GNRL_CTRL1,
272 			       &buf, sizeof(buf));
273 	if (ret < 0)
274 		return ret;
275 	msleep(SX9360_REG_GNRL_REG_2_PERIOD_MS(be16_to_cpu(buf)));
276 
277 	return 0;
278 }
279 
280 static int sx9360_read_gain(struct sx_common_data *data,
281 			    const struct iio_chan_spec *chan, int *val)
282 {
283 	unsigned int reg, regval;
284 	int ret;
285 
286 	reg = SX9360_REG_PROX_CTRL0_PHR + chan->channel;
287 	ret = regmap_read(data->regmap, reg, &regval);
288 	if (ret)
289 		return ret;
290 
291 	*val = 1 << FIELD_GET(SX9360_REG_PROX_CTRL0_GAIN_MASK, regval);
292 
293 	return IIO_VAL_INT;
294 }
295 
296 static int sx9360_read_samp_freq(struct sx_common_data *data,
297 				 int *val, int *val2)
298 {
299 	int ret, divisor;
300 	__be16 buf;
301 
302 	ret = regmap_bulk_read(data->regmap, SX9360_REG_GNRL_CTRL1,
303 			       &buf, sizeof(buf));
304 	if (ret < 0)
305 		return ret;
306 	divisor = be16_to_cpu(buf);
307 	if (divisor == 0) {
308 		*val = 0;
309 		return IIO_VAL_INT;
310 	}
311 
312 	*val = SX9360_FOSC_HZ;
313 	*val2 = divisor * 8192;
314 
315 	return IIO_VAL_FRACTIONAL;
316 }
317 
318 static int sx9360_read_raw(struct iio_dev *indio_dev,
319 			   const struct iio_chan_spec *chan,
320 			   int *val, int *val2, long mask)
321 {
322 	struct sx_common_data *data = iio_priv(indio_dev);
323 	int ret;
324 
325 	switch (mask) {
326 	case IIO_CHAN_INFO_RAW:
327 		ret = iio_device_claim_direct_mode(indio_dev);
328 		if (ret)
329 			return ret;
330 
331 		ret = sx_common_read_proximity(data, chan, val);
332 		iio_device_release_direct_mode(indio_dev);
333 		return ret;
334 	case IIO_CHAN_INFO_HARDWAREGAIN:
335 		ret = iio_device_claim_direct_mode(indio_dev);
336 		if (ret)
337 			return ret;
338 
339 		ret = sx9360_read_gain(data, chan, val);
340 		iio_device_release_direct_mode(indio_dev);
341 		return ret;
342 	case IIO_CHAN_INFO_SAMP_FREQ:
343 		return sx9360_read_samp_freq(data, val, val2);
344 	default:
345 		return -EINVAL;
346 	}
347 }
348 
349 static const char *sx9360_channel_labels[SX9360_NUM_CHANNELS] = {
350 	"reference", "main",
351 };
352 
353 static int sx9360_read_label(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
354 			     char *label)
355 {
356 	return sysfs_emit(label, "%s\n", sx9360_channel_labels[chan->channel]);
357 }
358 
359 static const int sx9360_gain_vals[] = { 1, 2, 4, 8 };
360 
361 static int sx9360_read_avail(struct iio_dev *indio_dev,
362 			     struct iio_chan_spec const *chan,
363 			     const int **vals, int *type, int *length,
364 			     long mask)
365 {
366 	if (chan->type != IIO_PROXIMITY)
367 		return -EINVAL;
368 
369 	switch (mask) {
370 	case IIO_CHAN_INFO_HARDWAREGAIN:
371 		*type = IIO_VAL_INT;
372 		*length = ARRAY_SIZE(sx9360_gain_vals);
373 		*vals = sx9360_gain_vals;
374 		return IIO_AVAIL_LIST;
375 	case IIO_CHAN_INFO_SAMP_FREQ:
376 		*type = IIO_VAL_INT_PLUS_MICRO;
377 		*length = ARRAY_SIZE(sx9360_samp_freq_interval) * 2;
378 		*vals = (int *)sx9360_samp_freq_interval;
379 		return IIO_AVAIL_RANGE;
380 	default:
381 		return -EINVAL;
382 	}
383 }
384 
385 static int sx9360_set_samp_freq(struct sx_common_data *data,
386 				int val, int val2)
387 {
388 	int ret, reg;
389 	__be16 buf;
390 
391 	reg = val * 8192 / SX9360_FOSC_HZ + val2 * 8192 / (SX9360_FOSC_MHZ);
392 	buf = cpu_to_be16(reg);
393 	mutex_lock(&data->mutex);
394 
395 	ret = regmap_bulk_write(data->regmap, SX9360_REG_GNRL_CTRL1, &buf,
396 				sizeof(buf));
397 
398 	mutex_unlock(&data->mutex);
399 
400 	return ret;
401 }
402 
403 static int sx9360_read_thresh(struct sx_common_data *data, int *val)
404 {
405 	unsigned int regval;
406 	int ret;
407 
408 	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL5, &regval);
409 	if (ret)
410 		return ret;
411 
412 	if (regval <= 1)
413 		*val = regval;
414 	else
415 		*val = (regval * regval) / 2;
416 
417 	return IIO_VAL_INT;
418 }
419 
420 static int sx9360_read_hysteresis(struct sx_common_data *data, int *val)
421 {
422 	unsigned int regval, pthresh;
423 	int ret;
424 
425 	ret = sx9360_read_thresh(data, &pthresh);
426 	if (ret < 0)
427 		return ret;
428 
429 	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL4, &regval);
430 	if (ret)
431 		return ret;
432 
433 	regval = FIELD_GET(SX9360_REG_PROX_CTRL4_HYST_MASK, regval);
434 	if (!regval)
435 		*val = 0;
436 	else
437 		*val = pthresh >> (5 - regval);
438 
439 	return IIO_VAL_INT;
440 }
441 
442 static int sx9360_read_far_debounce(struct sx_common_data *data, int *val)
443 {
444 	unsigned int regval;
445 	int ret;
446 
447 	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL4, &regval);
448 	if (ret)
449 		return ret;
450 
451 	regval = FIELD_GET(SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK, regval);
452 	if (regval)
453 		*val = 1 << regval;
454 	else
455 		*val = 0;
456 
457 	return IIO_VAL_INT;
458 }
459 
460 static int sx9360_read_close_debounce(struct sx_common_data *data, int *val)
461 {
462 	unsigned int regval;
463 	int ret;
464 
465 	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL4, &regval);
466 	if (ret)
467 		return ret;
468 
469 	regval = FIELD_GET(SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK, regval);
470 	if (regval)
471 		*val = 1 << regval;
472 	else
473 		*val = 0;
474 
475 	return IIO_VAL_INT;
476 }
477 
478 static int sx9360_read_event_val(struct iio_dev *indio_dev,
479 				 const struct iio_chan_spec *chan,
480 				 enum iio_event_type type,
481 				 enum iio_event_direction dir,
482 				 enum iio_event_info info, int *val, int *val2)
483 {
484 	struct sx_common_data *data = iio_priv(indio_dev);
485 
486 	if (chan->type != IIO_PROXIMITY)
487 		return -EINVAL;
488 
489 	switch (info) {
490 	case IIO_EV_INFO_VALUE:
491 		return sx9360_read_thresh(data, val);
492 	case IIO_EV_INFO_PERIOD:
493 		switch (dir) {
494 		case IIO_EV_DIR_RISING:
495 			return sx9360_read_far_debounce(data, val);
496 		case IIO_EV_DIR_FALLING:
497 			return sx9360_read_close_debounce(data, val);
498 		default:
499 			return -EINVAL;
500 		}
501 	case IIO_EV_INFO_HYSTERESIS:
502 		return sx9360_read_hysteresis(data, val);
503 	default:
504 		return -EINVAL;
505 	}
506 }
507 
508 static int sx9360_write_thresh(struct sx_common_data *data, int _val)
509 {
510 	unsigned int val = _val;
511 	int ret;
512 
513 	if (val >= 1)
514 		val = int_sqrt(2 * val);
515 
516 	if (val > 0xff)
517 		return -EINVAL;
518 
519 	mutex_lock(&data->mutex);
520 	ret = regmap_write(data->regmap, SX9360_REG_PROX_CTRL5, val);
521 	mutex_unlock(&data->mutex);
522 
523 	return ret;
524 }
525 
526 static int sx9360_write_hysteresis(struct sx_common_data *data, int _val)
527 {
528 	unsigned int hyst, val = _val;
529 	int ret, pthresh;
530 
531 	ret = sx9360_read_thresh(data, &pthresh);
532 	if (ret < 0)
533 		return ret;
534 
535 	if (val == 0)
536 		hyst = 0;
537 	else if (val >= pthresh >> 2)
538 		hyst = 3;
539 	else if (val >= pthresh >> 3)
540 		hyst = 2;
541 	else if (val >= pthresh >> 4)
542 		hyst = 1;
543 	else
544 		return -EINVAL;
545 
546 	hyst = FIELD_PREP(SX9360_REG_PROX_CTRL4_HYST_MASK, hyst);
547 	mutex_lock(&data->mutex);
548 	ret = regmap_update_bits(data->regmap, SX9360_REG_PROX_CTRL4,
549 				 SX9360_REG_PROX_CTRL4_HYST_MASK, hyst);
550 	mutex_unlock(&data->mutex);
551 
552 	return ret;
553 }
554 
555 static int sx9360_write_far_debounce(struct sx_common_data *data, int _val)
556 {
557 	unsigned int regval, val = _val;
558 	int ret;
559 
560 	if (val > 0)
561 		val = ilog2(val);
562 	if (!FIELD_FIT(SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK, val))
563 		return -EINVAL;
564 
565 	regval = FIELD_PREP(SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK, val);
566 
567 	mutex_lock(&data->mutex);
568 	ret = regmap_update_bits(data->regmap, SX9360_REG_PROX_CTRL4,
569 				 SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK,
570 				 regval);
571 	mutex_unlock(&data->mutex);
572 
573 	return ret;
574 }
575 
576 static int sx9360_write_close_debounce(struct sx_common_data *data, int _val)
577 {
578 	unsigned int regval, val = _val;
579 	int ret;
580 
581 	if (val > 0)
582 		val = ilog2(val);
583 	if (!FIELD_FIT(SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK, val))
584 		return -EINVAL;
585 
586 	regval = FIELD_PREP(SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK, val);
587 
588 	mutex_lock(&data->mutex);
589 	ret = regmap_update_bits(data->regmap, SX9360_REG_PROX_CTRL4,
590 				 SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK,
591 				 regval);
592 	mutex_unlock(&data->mutex);
593 
594 	return ret;
595 }
596 
597 static int sx9360_write_event_val(struct iio_dev *indio_dev,
598 				  const struct iio_chan_spec *chan,
599 				  enum iio_event_type type,
600 				  enum iio_event_direction dir,
601 				  enum iio_event_info info, int val, int val2)
602 {
603 	struct sx_common_data *data = iio_priv(indio_dev);
604 
605 	if (chan->type != IIO_PROXIMITY)
606 		return -EINVAL;
607 
608 	switch (info) {
609 	case IIO_EV_INFO_VALUE:
610 		return sx9360_write_thresh(data, val);
611 	case IIO_EV_INFO_PERIOD:
612 		switch (dir) {
613 		case IIO_EV_DIR_RISING:
614 			return sx9360_write_far_debounce(data, val);
615 		case IIO_EV_DIR_FALLING:
616 			return sx9360_write_close_debounce(data, val);
617 		default:
618 			return -EINVAL;
619 		}
620 	case IIO_EV_INFO_HYSTERESIS:
621 		return sx9360_write_hysteresis(data, val);
622 	default:
623 		return -EINVAL;
624 	}
625 }
626 
627 static int sx9360_write_gain(struct sx_common_data *data,
628 			     const struct iio_chan_spec *chan, int val)
629 {
630 	unsigned int gain, reg;
631 	int ret;
632 
633 	gain = ilog2(val);
634 	reg = SX9360_REG_PROX_CTRL0_PHR + chan->channel;
635 	gain = FIELD_PREP(SX9360_REG_PROX_CTRL0_GAIN_MASK, gain);
636 
637 	mutex_lock(&data->mutex);
638 	ret = regmap_update_bits(data->regmap, reg,
639 				 SX9360_REG_PROX_CTRL0_GAIN_MASK,
640 				 gain);
641 	mutex_unlock(&data->mutex);
642 
643 	return ret;
644 }
645 
646 static int sx9360_write_raw(struct iio_dev *indio_dev,
647 			    const struct iio_chan_spec *chan, int val, int val2,
648 			    long mask)
649 {
650 	struct sx_common_data *data = iio_priv(indio_dev);
651 
652 	switch (mask) {
653 	case IIO_CHAN_INFO_SAMP_FREQ:
654 		return sx9360_set_samp_freq(data, val, val2);
655 	case IIO_CHAN_INFO_HARDWAREGAIN:
656 		return sx9360_write_gain(data, chan, val);
657 	default:
658 		return -EINVAL;
659 	}
660 }
661 
662 static const struct sx_common_reg_default sx9360_default_regs[] = {
663 	{ SX9360_REG_IRQ_MSK, 0x00 },
664 	{ SX9360_REG_IRQ_CFG, 0x00 },
665 	/*
666 	 * The lower 2 bits should not be set as it enable sensors measurements.
667 	 * Turning the detection on before the configuration values are set to
668 	 * good values can cause the device to return erroneous readings.
669 	 */
670 	{ SX9360_REG_GNRL_CTRL0, 0x00 },
671 	{ SX9360_REG_GNRL_CTRL1, 0x00 },
672 	{ SX9360_REG_GNRL_CTRL2, SX9360_REG_GNRL_CTRL2_PERIOD_102MS },
673 
674 	{ SX9360_REG_AFE_CTRL1, 0x00 },
675 	{ SX9360_REG_AFE_PARAM0_PHR, SX9360_REG_AFE_PARAM0_RSVD |
676 		SX9360_REG_AFE_PARAM0_RESOLUTION_128 },
677 	{ SX9360_REG_AFE_PARAM1_PHR, SX9360_REG_AFE_PARAM1_AGAIN_PHM_6PF |
678 		SX9360_REG_AFE_PARAM1_FREQ_83_33HZ },
679 	{ SX9360_REG_AFE_PARAM0_PHM, SX9360_REG_AFE_PARAM0_RSVD |
680 		SX9360_REG_AFE_PARAM0_RESOLUTION_128 },
681 	{ SX9360_REG_AFE_PARAM1_PHM, SX9360_REG_AFE_PARAM1_AGAIN_PHM_6PF |
682 		SX9360_REG_AFE_PARAM1_FREQ_83_33HZ },
683 
684 	{ SX9360_REG_PROX_CTRL0_PHR, SX9360_REG_PROX_CTRL0_GAIN_1 |
685 		SX9360_REG_PROX_CTRL0_RAWFILT_1P50 },
686 	{ SX9360_REG_PROX_CTRL0_PHM, SX9360_REG_PROX_CTRL0_GAIN_1 |
687 		SX9360_REG_PROX_CTRL0_RAWFILT_1P50 },
688 	{ SX9360_REG_PROX_CTRL1, SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_16K },
689 	{ SX9360_REG_PROX_CTRL2, SX9360_REG_PROX_CTRL2_AVGDEB_2SAMPLES |
690 		SX9360_REG_PROX_CTRL2_AVGPOS_THRESH_16K },
691 	{ SX9360_REG_PROX_CTRL3, SX9360_REG_PROX_CTRL3_AVGNEG_FILT_2 |
692 		SX9360_REG_PROX_CTRL3_AVGPOS_FILT_256 },
693 	{ SX9360_REG_PROX_CTRL4, 0x00 },
694 	{ SX9360_REG_PROX_CTRL5, SX9360_REG_PROX_CTRL5_PROXTHRESH_32 },
695 };
696 
697 /* Activate all channels and perform an initial compensation. */
698 static int sx9360_init_compensation(struct iio_dev *indio_dev)
699 {
700 	struct sx_common_data *data = iio_priv(indio_dev);
701 	unsigned int val;
702 	int ret;
703 
704 	/* run the compensation phase on all channels */
705 	ret = regmap_update_bits(data->regmap, SX9360_REG_STAT,
706 				 SX9360_REG_STAT_COMPSTAT_MASK,
707 				 SX9360_REG_STAT_COMPSTAT_MASK);
708 	if (ret)
709 		return ret;
710 
711 	return regmap_read_poll_timeout(data->regmap, SX9360_REG_STAT, val,
712 				       !(val & SX9360_REG_STAT_COMPSTAT_MASK),
713 				       20000, 2000000);
714 }
715 
716 static const struct sx_common_reg_default *
717 sx9360_get_default_reg(struct device *dev, int idx,
718 		       struct sx_common_reg_default *reg_def)
719 {
720 	u32 raw = 0, pos = 0;
721 	int ret;
722 
723 	memcpy(reg_def, &sx9360_default_regs[idx], sizeof(*reg_def));
724 	switch (reg_def->reg) {
725 	case SX9360_REG_AFE_PARAM0_PHR:
726 	case SX9360_REG_AFE_PARAM0_PHM:
727 		ret = device_property_read_u32(dev, "semtech,resolution", &raw);
728 		if (ret)
729 			break;
730 
731 		raw = ilog2(raw) - 3;
732 
733 		reg_def->def &= ~SX9360_REG_AFE_PARAM0_RESOLUTION_MASK;
734 		reg_def->def |= FIELD_PREP(SX9360_REG_AFE_PARAM0_RESOLUTION_MASK, raw);
735 		break;
736 	case SX9360_REG_PROX_CTRL0_PHR:
737 	case SX9360_REG_PROX_CTRL0_PHM:
738 		ret = device_property_read_u32(dev, "semtech,proxraw-strength", &raw);
739 		if (ret)
740 			break;
741 
742 		reg_def->def &= ~SX9360_REG_PROX_CTRL0_RAWFILT_MASK;
743 		reg_def->def |= FIELD_PREP(SX9360_REG_PROX_CTRL0_RAWFILT_MASK, raw);
744 		break;
745 	case SX9360_REG_PROX_CTRL3:
746 		ret = device_property_read_u32(dev, "semtech,avg-pos-strength",
747 					       &pos);
748 		if (ret)
749 			break;
750 
751 		/* Powers of 2, except for a gap between 16 and 64 */
752 		raw = clamp(ilog2(pos), 3, 11) - (pos >= 32 ? 4 : 3);
753 		reg_def->def &= ~SX9360_REG_PROX_CTRL3_AVGPOS_FILT_MASK;
754 		reg_def->def |= FIELD_PREP(SX9360_REG_PROX_CTRL3_AVGPOS_FILT_MASK, raw);
755 		break;
756 	}
757 
758 	return reg_def;
759 }
760 
761 static int sx9360_check_whoami(struct device *dev, struct iio_dev *indio_dev)
762 {
763 	/*
764 	 * Only one sensor for this driver. Assuming the device tree
765 	 * is correct, just set the sensor name.
766 	 */
767 	indio_dev->name = "sx9360";
768 	return 0;
769 }
770 
771 static const struct sx_common_chip_info sx9360_chip_info = {
772 	.reg_stat = SX9360_REG_STAT,
773 	.reg_irq_msk = SX9360_REG_IRQ_MSK,
774 	.reg_enable_chan = SX9360_REG_GNRL_CTRL0,
775 	.reg_reset = SX9360_REG_RESET,
776 
777 	.mask_enable_chan = SX9360_REG_GNRL_CTRL0_PHEN_MASK,
778 	.stat_offset = 2,
779 	.num_channels = SX9360_NUM_CHANNELS,
780 	.num_default_regs = ARRAY_SIZE(sx9360_default_regs),
781 
782 	.ops = {
783 		.read_prox_data = sx9360_read_prox_data,
784 		.check_whoami = sx9360_check_whoami,
785 		.init_compensation = sx9360_init_compensation,
786 		.wait_for_sample = sx9360_wait_for_sample,
787 		.get_default_reg = sx9360_get_default_reg,
788 	},
789 
790 	.iio_channels = sx9360_channels,
791 	.num_iio_channels = ARRAY_SIZE(sx9360_channels),
792 	.iio_info =  {
793 		.read_raw = sx9360_read_raw,
794 		.read_avail = sx9360_read_avail,
795 		.read_label = sx9360_read_label,
796 		.read_event_value = sx9360_read_event_val,
797 		.write_event_value = sx9360_write_event_val,
798 		.write_raw = sx9360_write_raw,
799 		.read_event_config = sx_common_read_event_config,
800 		.write_event_config = sx_common_write_event_config,
801 	},
802 };
803 
804 static int sx9360_probe(struct i2c_client *client)
805 {
806 	return sx_common_probe(client, &sx9360_chip_info, &sx9360_regmap_config);
807 }
808 
809 static int __maybe_unused sx9360_suspend(struct device *dev)
810 {
811 	struct sx_common_data *data = iio_priv(dev_get_drvdata(dev));
812 	unsigned int regval;
813 	int ret;
814 
815 	disable_irq_nosync(data->client->irq);
816 
817 	mutex_lock(&data->mutex);
818 	ret = regmap_read(data->regmap, SX9360_REG_GNRL_CTRL0, &regval);
819 
820 	data->suspend_ctrl =
821 		FIELD_GET(SX9360_REG_GNRL_CTRL0_PHEN_MASK, regval);
822 
823 	if (ret < 0)
824 		goto out;
825 
826 	/* Disable all phases, send the device to sleep. */
827 	ret = regmap_write(data->regmap, SX9360_REG_GNRL_CTRL0, 0);
828 
829 out:
830 	mutex_unlock(&data->mutex);
831 	return ret;
832 }
833 
834 static int __maybe_unused sx9360_resume(struct device *dev)
835 {
836 	struct sx_common_data *data = iio_priv(dev_get_drvdata(dev));
837 	int ret;
838 
839 	mutex_lock(&data->mutex);
840 	ret = regmap_update_bits(data->regmap, SX9360_REG_GNRL_CTRL0,
841 				 SX9360_REG_GNRL_CTRL0_PHEN_MASK,
842 				 data->suspend_ctrl);
843 	mutex_unlock(&data->mutex);
844 	if (ret)
845 		return ret;
846 
847 	enable_irq(data->client->irq);
848 	return 0;
849 }
850 
851 static SIMPLE_DEV_PM_OPS(sx9360_pm_ops, sx9360_suspend, sx9360_resume);
852 
853 static const struct acpi_device_id sx9360_acpi_match[] = {
854 	{ "STH9360", SX9360_WHOAMI_VALUE },
855 	{ }
856 };
857 MODULE_DEVICE_TABLE(acpi, sx9360_acpi_match);
858 
859 static const struct of_device_id sx9360_of_match[] = {
860 	{ .compatible = "semtech,sx9360", (void *)SX9360_WHOAMI_VALUE },
861 	{ }
862 };
863 MODULE_DEVICE_TABLE(of, sx9360_of_match);
864 
865 static const struct i2c_device_id sx9360_id[] = {
866 	{"sx9360", SX9360_WHOAMI_VALUE },
867 	{ }
868 };
869 MODULE_DEVICE_TABLE(i2c, sx9360_id);
870 
871 static struct i2c_driver sx9360_driver = {
872 	.driver = {
873 		.name	= "sx9360",
874 		.acpi_match_table = sx9360_acpi_match,
875 		.of_match_table = sx9360_of_match,
876 		.pm = &sx9360_pm_ops,
877 
878 		/*
879 		 * Lots of i2c transfers in probe + over 200 ms waiting in
880 		 * sx9360_init_compensation() mean a slow probe; prefer async
881 		 * so we don't delay boot if we're builtin to the kernel.
882 		 */
883 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
884 	},
885 	.probe_new	= sx9360_probe,
886 	.id_table	= sx9360_id,
887 };
888 module_i2c_driver(sx9360_driver);
889 
890 MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
891 MODULE_DESCRIPTION("Driver for Semtech SX9360 proximity sensor");
892 MODULE_LICENSE("GPL v2");
893 MODULE_IMPORT_NS(SEMTECH_PROX);
894