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/bits.h>
11 #include <linux/bitfield.h>
12 #include <linux/delay.h>
13 #include <linux/i2c.h>
14 #include <linux/interrupt.h>
15 #include <linux/kernel.h>
16 #include <linux/log2.h>
17 #include <linux/mod_devicetable.h>
18 #include <linux/module.h>
19 #include <linux/pm.h>
20 #include <linux/property.h>
21 #include <linux/regmap.h>
22 
23 #include <linux/iio/iio.h>
24 
25 #include "sx_common.h"
26 
27 /* Nominal Oscillator Frequency. */
28 #define SX9360_FOSC_MHZ			4
29 #define SX9360_FOSC_HZ			(SX9360_FOSC_MHZ * 1000000)
30 
31 /* Register definitions. */
32 #define SX9360_REG_IRQ_SRC		SX_COMMON_REG_IRQ_SRC
33 #define SX9360_REG_STAT		0x01
34 #define SX9360_REG_STAT_COMPSTAT_MASK	GENMASK(2, 1)
35 #define SX9360_REG_IRQ_MSK		0x02
36 #define SX9360_CONVDONE_IRQ		BIT(0)
37 #define SX9360_FAR_IRQ			BIT(2)
38 #define SX9360_CLOSE_IRQ		BIT(3)
39 #define SX9360_REG_IRQ_CFG		0x03
40 
41 #define SX9360_REG_GNRL_CTRL0		0x10
42 #define SX9360_REG_GNRL_CTRL0_PHEN_MASK GENMASK(1, 0)
43 #define SX9360_REG_GNRL_CTRL1		0x11
44 #define SX9360_REG_GNRL_CTRL1_SCANPERIOD_MASK GENMASK(2, 0)
45 #define SX9360_REG_GNRL_CTRL2		0x12
46 #define SX9360_REG_GNRL_CTRL2_PERIOD_102MS	0x32
47 #define SX9360_REG_GNRL_REG_2_PERIOD_MS(_r)	\
48 	(((_r) * 8192) / (SX9360_FOSC_HZ / 1000))
49 #define SX9360_REG_GNRL_FREQ_2_REG(_f)  (((_f) * 8192) / SX9360_FOSC_HZ)
50 #define SX9360_REG_GNRL_REG_2_FREQ(_r)  (SX9360_FOSC_HZ / ((_r) * 8192))
51 
52 #define SX9360_REG_AFE_CTRL1		0x21
53 #define SX9360_REG_AFE_CTRL1_RESFILTIN_MASK GENMASK(3, 0)
54 #define SX9360_REG_AFE_CTRL1_RESFILTIN_0OHMS 0
55 #define SX9360_REG_AFE_PARAM0_PHR	0x22
56 #define SX9360_REG_AFE_PARAM1_PHR	0x23
57 #define SX9360_REG_AFE_PARAM0_PHM	0x24
58 #define SX9360_REG_AFE_PARAM0_RSVD		0x08
59 #define SX9360_REG_AFE_PARAM0_RESOLUTION_MASK	GENMASK(2, 0)
60 #define SX9360_REG_AFE_PARAM0_RESOLUTION_128	0x02
61 #define SX9360_REG_AFE_PARAM1_PHM	0x25
62 #define SX9360_REG_AFE_PARAM1_AGAIN_PHM_6PF	0x40
63 #define SX9360_REG_AFE_PARAM1_FREQ_83_33HZ	0x06
64 
65 #define SX9360_REG_PROX_CTRL0_PHR	0x40
66 #define SX9360_REG_PROX_CTRL0_PHM	0x41
67 #define SX9360_REG_PROX_CTRL0_GAIN_MASK	GENMASK(5, 3)
68 #define SX9360_REG_PROX_CTRL0_GAIN_1		0x80
69 #define SX9360_REG_PROX_CTRL0_RAWFILT_MASK	GENMASK(2, 0)
70 #define SX9360_REG_PROX_CTRL0_RAWFILT_1P50	0x01
71 #define SX9360_REG_PROX_CTRL1		0x42
72 #define SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_MASK	GENMASK(5, 3)
73 #define SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_16K 0x20
74 #define SX9360_REG_PROX_CTRL2		0x43
75 #define SX9360_REG_PROX_CTRL2_AVGDEB_MASK	GENMASK(7, 6)
76 #define SX9360_REG_PROX_CTRL2_AVGDEB_2SAMPLES	0x40
77 #define SX9360_REG_PROX_CTRL2_AVGPOS_THRESH_16K	0x20
78 #define SX9360_REG_PROX_CTRL3		0x44
79 #define SX9360_REG_PROX_CTRL3_AVGNEG_FILT_MASK	GENMASK(5, 3)
80 #define SX9360_REG_PROX_CTRL3_AVGNEG_FILT_2	0x08
81 #define SX9360_REG_PROX_CTRL3_AVGPOS_FILT_MASK	GENMASK(2, 0)
82 #define SX9360_REG_PROX_CTRL3_AVGPOS_FILT_256	0x04
83 #define SX9360_REG_PROX_CTRL4		0x45
84 #define SX9360_REG_PROX_CTRL4_HYST_MASK			GENMASK(5, 4)
85 #define SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK	GENMASK(3, 2)
86 #define SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK		GENMASK(1, 0)
87 #define SX9360_REG_PROX_CTRL5		0x46
88 #define SX9360_REG_PROX_CTRL5_PROXTHRESH_32	0x08
89 
90 #define SX9360_REG_REF_CORR0		0x60
91 #define SX9360_REG_REF_CORR1		0x61
92 
93 #define SX9360_REG_USEFUL_PHR_MSB		0x90
94 #define SX9360_REG_USEFUL_PHR_LSB		0x91
95 
96 #define SX9360_REG_OFFSET_PMR_MSB		0x92
97 #define SX9360_REG_OFFSET_PMR_LSB		0x93
98 
99 #define SX9360_REG_USEFUL_PHM_MSB		0x94
100 #define SX9360_REG_USEFUL_PHM_LSB		0x95
101 
102 #define SX9360_REG_AVG_PHM_MSB		0x96
103 #define SX9360_REG_AVG_PHM_LSB		0x97
104 
105 #define SX9360_REG_DIFF_PHM_MSB		0x98
106 #define SX9360_REG_DIFF_PHM_LSB		0x99
107 
108 #define SX9360_REG_OFFSET_PHM_MSB		0x9a
109 #define SX9360_REG_OFFSET_PHM_LSB		0x9b
110 
111 #define SX9360_REG_USE_FILTER_MSB		0x9a
112 #define SX9360_REG_USE_FILTER_LSB		0x9b
113 
114 #define SX9360_REG_RESET		0xcf
115 /* Write this to REG_RESET to do a soft reset. */
116 #define SX9360_SOFT_RESET		0xde
117 
118 #define SX9360_REG_WHOAMI		0xfa
119 #define   SX9360_WHOAMI_VALUE				0x60
120 
121 #define SX9360_REG_REVISION		0xfe
122 
123 /* 2 channels, Phase Reference and Measurement. */
124 #define SX9360_NUM_CHANNELS		2
125 
126 static const struct iio_chan_spec sx9360_channels[] = {
127 	{
128 		.type = IIO_PROXIMITY,
129 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
130 				      BIT(IIO_CHAN_INFO_HARDWAREGAIN),
131 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
132 		.info_mask_separate_available =
133 			BIT(IIO_CHAN_INFO_HARDWAREGAIN),
134 		.info_mask_shared_by_all_available =
135 			BIT(IIO_CHAN_INFO_SAMP_FREQ),
136 		.indexed = 1,
137 		.address = SX9360_REG_USEFUL_PHR_MSB,
138 		.channel = 0,
139 		.scan_index = 0,
140 		.scan_type = {
141 			.sign = 's',
142 			.realbits = 12,
143 			.storagebits = 16,
144 			.endianness = IIO_BE,
145 		},
146 	},
147 	{
148 		.type = IIO_PROXIMITY,
149 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
150 				      BIT(IIO_CHAN_INFO_HARDWAREGAIN),
151 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
152 		.info_mask_separate_available =
153 			BIT(IIO_CHAN_INFO_HARDWAREGAIN),
154 		.info_mask_shared_by_all_available =
155 			BIT(IIO_CHAN_INFO_SAMP_FREQ),
156 		.indexed = 1,
157 		.address = SX9360_REG_USEFUL_PHM_MSB,
158 		.event_spec = sx_common_events,
159 		.num_event_specs = ARRAY_SIZE(sx_common_events),
160 		.channel = 1,
161 		.scan_index = 1,
162 		.scan_type = {
163 			.sign = 's',
164 			.realbits = 12,
165 			.storagebits = 16,
166 			.endianness = IIO_BE,
167 		},
168 	},
169 	IIO_CHAN_SOFT_TIMESTAMP(2),
170 };
171 
172 /*
173  * Each entry contains the integer part (val) and the fractional part, in micro
174  * seconds. It conforms to the IIO output IIO_VAL_INT_PLUS_MICRO.
175  *
176  * The frequency control register holds the period, with a ~2ms increment.
177  * Therefore the smallest frequency is 4MHz / (2047 * 8192),
178  * The fastest is 4MHz / 8192.
179  * The interval is not linear, but given there is 2047 possible value,
180  * Returns the fake increment of (Max-Min)/2047
181  */
182 static const struct {
183 	int val;
184 	int val2;
185 } sx9360_samp_freq_interval[] = {
186 	{ 0, 281250 },  /* 4MHz / (8192 * 2047) */
187 	{ 0, 281250 },
188 	{ 448, 281250 },  /* 4MHz / 8192 */
189 };
190 
191 static const struct regmap_range sx9360_writable_reg_ranges[] = {
192 	/*
193 	 * To set COMPSTAT for compensation, even if datasheet says register is
194 	 * RO.
195 	 */
196 	regmap_reg_range(SX9360_REG_STAT, SX9360_REG_IRQ_CFG),
197 	regmap_reg_range(SX9360_REG_GNRL_CTRL0, SX9360_REG_GNRL_CTRL2),
198 	regmap_reg_range(SX9360_REG_AFE_CTRL1, SX9360_REG_AFE_PARAM1_PHM),
199 	regmap_reg_range(SX9360_REG_PROX_CTRL0_PHR, SX9360_REG_PROX_CTRL5),
200 	regmap_reg_range(SX9360_REG_REF_CORR0, SX9360_REG_REF_CORR1),
201 	regmap_reg_range(SX9360_REG_OFFSET_PMR_MSB, SX9360_REG_OFFSET_PMR_LSB),
202 	regmap_reg_range(SX9360_REG_RESET, SX9360_REG_RESET),
203 };
204 
205 static const struct regmap_access_table sx9360_writeable_regs = {
206 	.yes_ranges = sx9360_writable_reg_ranges,
207 	.n_yes_ranges = ARRAY_SIZE(sx9360_writable_reg_ranges),
208 };
209 
210 /*
211  * All allocated registers are readable, so we just list unallocated
212  * ones.
213  */
214 static const struct regmap_range sx9360_non_readable_reg_ranges[] = {
215 	regmap_reg_range(SX9360_REG_IRQ_CFG + 1, SX9360_REG_GNRL_CTRL0 - 1),
216 	regmap_reg_range(SX9360_REG_GNRL_CTRL2 + 1, SX9360_REG_AFE_CTRL1 - 1),
217 	regmap_reg_range(SX9360_REG_AFE_PARAM1_PHM + 1,
218 			 SX9360_REG_PROX_CTRL0_PHR - 1),
219 	regmap_reg_range(SX9360_REG_PROX_CTRL5 + 1, SX9360_REG_REF_CORR0 - 1),
220 	regmap_reg_range(SX9360_REG_REF_CORR1 + 1,
221 			 SX9360_REG_USEFUL_PHR_MSB - 1),
222 	regmap_reg_range(SX9360_REG_USE_FILTER_LSB + 1, SX9360_REG_RESET - 1),
223 	regmap_reg_range(SX9360_REG_RESET + 1, SX9360_REG_WHOAMI - 1),
224 	regmap_reg_range(SX9360_REG_WHOAMI + 1, SX9360_REG_REVISION - 1),
225 };
226 
227 static const struct regmap_access_table sx9360_readable_regs = {
228 	.no_ranges = sx9360_non_readable_reg_ranges,
229 	.n_no_ranges = ARRAY_SIZE(sx9360_non_readable_reg_ranges),
230 };
231 
232 static const struct regmap_range sx9360_volatile_reg_ranges[] = {
233 	regmap_reg_range(SX9360_REG_IRQ_SRC, SX9360_REG_STAT),
234 	regmap_reg_range(SX9360_REG_USEFUL_PHR_MSB, SX9360_REG_USE_FILTER_LSB),
235 	regmap_reg_range(SX9360_REG_WHOAMI, SX9360_REG_WHOAMI),
236 	regmap_reg_range(SX9360_REG_REVISION, SX9360_REG_REVISION),
237 };
238 
239 static const struct regmap_access_table sx9360_volatile_regs = {
240 	.yes_ranges = sx9360_volatile_reg_ranges,
241 	.n_yes_ranges = ARRAY_SIZE(sx9360_volatile_reg_ranges),
242 };
243 
244 static const struct regmap_config sx9360_regmap_config = {
245 	.reg_bits = 8,
246 	.val_bits = 8,
247 
248 	.max_register = SX9360_REG_REVISION,
249 	.cache_type = REGCACHE_RBTREE,
250 
251 	.wr_table = &sx9360_writeable_regs,
252 	.rd_table = &sx9360_readable_regs,
253 	.volatile_table = &sx9360_volatile_regs,
254 };
255 
sx9360_read_prox_data(struct sx_common_data * data,const struct iio_chan_spec * chan,__be16 * val)256 static int sx9360_read_prox_data(struct sx_common_data *data,
257 				 const struct iio_chan_spec *chan,
258 				 __be16 *val)
259 {
260 	return regmap_bulk_read(data->regmap, chan->address, val, sizeof(*val));
261 }
262 
263 /*
264  * If we have no interrupt support, we have to wait for a scan period
265  * after enabling a channel to get a result.
266  */
sx9360_wait_for_sample(struct sx_common_data * data)267 static int sx9360_wait_for_sample(struct sx_common_data *data)
268 {
269 	int ret;
270 	__be16 buf;
271 
272 	ret = regmap_bulk_read(data->regmap, SX9360_REG_GNRL_CTRL1,
273 			       &buf, sizeof(buf));
274 	if (ret < 0)
275 		return ret;
276 	msleep(SX9360_REG_GNRL_REG_2_PERIOD_MS(be16_to_cpu(buf)));
277 
278 	return 0;
279 }
280 
sx9360_read_gain(struct sx_common_data * data,const struct iio_chan_spec * chan,int * val)281 static int sx9360_read_gain(struct sx_common_data *data,
282 			    const struct iio_chan_spec *chan, int *val)
283 {
284 	unsigned int reg, regval;
285 	int ret;
286 
287 	reg = SX9360_REG_PROX_CTRL0_PHR + chan->channel;
288 	ret = regmap_read(data->regmap, reg, &regval);
289 	if (ret)
290 		return ret;
291 
292 	*val = 1 << FIELD_GET(SX9360_REG_PROX_CTRL0_GAIN_MASK, regval);
293 
294 	return IIO_VAL_INT;
295 }
296 
sx9360_read_samp_freq(struct sx_common_data * data,int * val,int * val2)297 static int sx9360_read_samp_freq(struct sx_common_data *data,
298 				 int *val, int *val2)
299 {
300 	int ret, divisor;
301 	__be16 buf;
302 
303 	ret = regmap_bulk_read(data->regmap, SX9360_REG_GNRL_CTRL1,
304 			       &buf, sizeof(buf));
305 	if (ret < 0)
306 		return ret;
307 	divisor = be16_to_cpu(buf);
308 	if (divisor == 0) {
309 		*val = 0;
310 		return IIO_VAL_INT;
311 	}
312 
313 	*val = SX9360_FOSC_HZ;
314 	*val2 = divisor * 8192;
315 
316 	return IIO_VAL_FRACTIONAL;
317 }
318 
sx9360_read_raw(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,int * val,int * val2,long mask)319 static int sx9360_read_raw(struct iio_dev *indio_dev,
320 			   const struct iio_chan_spec *chan,
321 			   int *val, int *val2, long mask)
322 {
323 	struct sx_common_data *data = iio_priv(indio_dev);
324 	int ret;
325 
326 	switch (mask) {
327 	case IIO_CHAN_INFO_RAW:
328 		if (!iio_device_claim_direct(indio_dev))
329 			return -EBUSY;
330 
331 		ret = sx_common_read_proximity(data, chan, val);
332 		iio_device_release_direct(indio_dev);
333 		return ret;
334 	case IIO_CHAN_INFO_HARDWAREGAIN:
335 		if (!iio_device_claim_direct(indio_dev))
336 			return -EBUSY;
337 
338 		ret = sx9360_read_gain(data, chan, val);
339 		iio_device_release_direct(indio_dev);
340 		return ret;
341 	case IIO_CHAN_INFO_SAMP_FREQ:
342 		return sx9360_read_samp_freq(data, val, val2);
343 	default:
344 		return -EINVAL;
345 	}
346 }
347 
348 static const char *sx9360_channel_labels[SX9360_NUM_CHANNELS] = {
349 	"reference", "main",
350 };
351 
sx9360_read_label(struct iio_dev * iio_dev,const struct iio_chan_spec * chan,char * label)352 static int sx9360_read_label(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
353 			     char *label)
354 {
355 	return sysfs_emit(label, "%s\n", sx9360_channel_labels[chan->channel]);
356 }
357 
358 static const int sx9360_gain_vals[] = { 1, 2, 4, 8 };
359 
sx9360_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long mask)360 static int sx9360_read_avail(struct iio_dev *indio_dev,
361 			     struct iio_chan_spec const *chan,
362 			     const int **vals, int *type, int *length,
363 			     long mask)
364 {
365 	if (chan->type != IIO_PROXIMITY)
366 		return -EINVAL;
367 
368 	switch (mask) {
369 	case IIO_CHAN_INFO_HARDWAREGAIN:
370 		*type = IIO_VAL_INT;
371 		*length = ARRAY_SIZE(sx9360_gain_vals);
372 		*vals = sx9360_gain_vals;
373 		return IIO_AVAIL_LIST;
374 	case IIO_CHAN_INFO_SAMP_FREQ:
375 		*type = IIO_VAL_INT_PLUS_MICRO;
376 		*length = ARRAY_SIZE(sx9360_samp_freq_interval) * 2;
377 		*vals = (int *)sx9360_samp_freq_interval;
378 		return IIO_AVAIL_RANGE;
379 	default:
380 		return -EINVAL;
381 	}
382 }
383 
sx9360_set_samp_freq(struct sx_common_data * data,int val,int val2)384 static int sx9360_set_samp_freq(struct sx_common_data *data,
385 				int val, int val2)
386 {
387 	int reg;
388 	__be16 buf;
389 
390 	reg = val * 8192 / SX9360_FOSC_HZ + val2 * 8192 / (SX9360_FOSC_MHZ);
391 	buf = cpu_to_be16(reg);
392 	guard(mutex)(&data->mutex);
393 
394 	return regmap_bulk_write(data->regmap, SX9360_REG_GNRL_CTRL1, &buf,
395 				 sizeof(buf));
396 }
397 
sx9360_read_thresh(struct sx_common_data * data,int * val)398 static int sx9360_read_thresh(struct sx_common_data *data, int *val)
399 {
400 	unsigned int regval;
401 	int ret;
402 
403 	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL5, &regval);
404 	if (ret)
405 		return ret;
406 
407 	if (regval <= 1)
408 		*val = regval;
409 	else
410 		*val = (regval * regval) / 2;
411 
412 	return IIO_VAL_INT;
413 }
414 
sx9360_read_hysteresis(struct sx_common_data * data,int * val)415 static int sx9360_read_hysteresis(struct sx_common_data *data, int *val)
416 {
417 	unsigned int regval, pthresh;
418 	int ret;
419 
420 	ret = sx9360_read_thresh(data, &pthresh);
421 	if (ret < 0)
422 		return ret;
423 
424 	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL4, &regval);
425 	if (ret)
426 		return ret;
427 
428 	regval = FIELD_GET(SX9360_REG_PROX_CTRL4_HYST_MASK, regval);
429 	if (!regval)
430 		*val = 0;
431 	else
432 		*val = pthresh >> (5 - regval);
433 
434 	return IIO_VAL_INT;
435 }
436 
sx9360_read_far_debounce(struct sx_common_data * data,int * val)437 static int sx9360_read_far_debounce(struct sx_common_data *data, int *val)
438 {
439 	unsigned int regval;
440 	int ret;
441 
442 	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL4, &regval);
443 	if (ret)
444 		return ret;
445 
446 	regval = FIELD_GET(SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK, regval);
447 	if (regval)
448 		*val = 1 << regval;
449 	else
450 		*val = 0;
451 
452 	return IIO_VAL_INT;
453 }
454 
sx9360_read_close_debounce(struct sx_common_data * data,int * val)455 static int sx9360_read_close_debounce(struct sx_common_data *data, int *val)
456 {
457 	unsigned int regval;
458 	int ret;
459 
460 	ret = regmap_read(data->regmap, SX9360_REG_PROX_CTRL4, &regval);
461 	if (ret)
462 		return ret;
463 
464 	regval = FIELD_GET(SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK, regval);
465 	if (regval)
466 		*val = 1 << regval;
467 	else
468 		*val = 0;
469 
470 	return IIO_VAL_INT;
471 }
472 
sx9360_read_event_val(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir,enum iio_event_info info,int * val,int * val2)473 static int sx9360_read_event_val(struct iio_dev *indio_dev,
474 				 const struct iio_chan_spec *chan,
475 				 enum iio_event_type type,
476 				 enum iio_event_direction dir,
477 				 enum iio_event_info info, int *val, int *val2)
478 {
479 	struct sx_common_data *data = iio_priv(indio_dev);
480 
481 	if (chan->type != IIO_PROXIMITY)
482 		return -EINVAL;
483 
484 	switch (info) {
485 	case IIO_EV_INFO_VALUE:
486 		return sx9360_read_thresh(data, val);
487 	case IIO_EV_INFO_PERIOD:
488 		switch (dir) {
489 		case IIO_EV_DIR_RISING:
490 			return sx9360_read_far_debounce(data, val);
491 		case IIO_EV_DIR_FALLING:
492 			return sx9360_read_close_debounce(data, val);
493 		default:
494 			return -EINVAL;
495 		}
496 	case IIO_EV_INFO_HYSTERESIS:
497 		return sx9360_read_hysteresis(data, val);
498 	default:
499 		return -EINVAL;
500 	}
501 }
502 
sx9360_write_thresh(struct sx_common_data * data,int _val)503 static int sx9360_write_thresh(struct sx_common_data *data, int _val)
504 {
505 	unsigned int val = _val;
506 
507 	if (val >= 1)
508 		val = int_sqrt(2 * val);
509 
510 	if (val > 0xff)
511 		return -EINVAL;
512 
513 	guard(mutex)(&data->mutex);
514 	return regmap_write(data->regmap, SX9360_REG_PROX_CTRL5, val);
515 }
516 
sx9360_write_hysteresis(struct sx_common_data * data,int _val)517 static int sx9360_write_hysteresis(struct sx_common_data *data, int _val)
518 {
519 	unsigned int hyst, val = _val;
520 	int ret, pthresh;
521 
522 	ret = sx9360_read_thresh(data, &pthresh);
523 	if (ret < 0)
524 		return ret;
525 
526 	if (val == 0)
527 		hyst = 0;
528 	else if (val >= pthresh >> 2)
529 		hyst = 3;
530 	else if (val >= pthresh >> 3)
531 		hyst = 2;
532 	else if (val >= pthresh >> 4)
533 		hyst = 1;
534 	else
535 		return -EINVAL;
536 
537 	hyst = FIELD_PREP(SX9360_REG_PROX_CTRL4_HYST_MASK, hyst);
538 	guard(mutex)(&data->mutex);
539 	return regmap_update_bits(data->regmap, SX9360_REG_PROX_CTRL4,
540 				  SX9360_REG_PROX_CTRL4_HYST_MASK, hyst);
541 }
542 
sx9360_write_far_debounce(struct sx_common_data * data,int _val)543 static int sx9360_write_far_debounce(struct sx_common_data *data, int _val)
544 {
545 	unsigned int regval, val = _val;
546 
547 	if (val > 0)
548 		val = ilog2(val);
549 	if (!FIELD_FIT(SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK, val))
550 		return -EINVAL;
551 
552 	regval = FIELD_PREP(SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK, val);
553 
554 	guard(mutex)(&data->mutex);
555 	return regmap_update_bits(data->regmap, SX9360_REG_PROX_CTRL4,
556 				  SX9360_REG_PROX_CTRL4_FAR_DEBOUNCE_MASK,
557 				  regval);
558 }
559 
sx9360_write_close_debounce(struct sx_common_data * data,int _val)560 static int sx9360_write_close_debounce(struct sx_common_data *data, int _val)
561 {
562 	unsigned int regval, val = _val;
563 
564 	if (val > 0)
565 		val = ilog2(val);
566 	if (!FIELD_FIT(SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK, val))
567 		return -EINVAL;
568 
569 	regval = FIELD_PREP(SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK, val);
570 
571 	guard(mutex)(&data->mutex);
572 	return regmap_update_bits(data->regmap, SX9360_REG_PROX_CTRL4,
573 				  SX9360_REG_PROX_CTRL4_CLOSE_DEBOUNCE_MASK,
574 				  regval);
575 }
576 
sx9360_write_event_val(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,enum iio_event_type type,enum iio_event_direction dir,enum iio_event_info info,int val,int val2)577 static int sx9360_write_event_val(struct iio_dev *indio_dev,
578 				  const struct iio_chan_spec *chan,
579 				  enum iio_event_type type,
580 				  enum iio_event_direction dir,
581 				  enum iio_event_info info, int val, int val2)
582 {
583 	struct sx_common_data *data = iio_priv(indio_dev);
584 
585 	if (chan->type != IIO_PROXIMITY)
586 		return -EINVAL;
587 
588 	switch (info) {
589 	case IIO_EV_INFO_VALUE:
590 		return sx9360_write_thresh(data, val);
591 	case IIO_EV_INFO_PERIOD:
592 		switch (dir) {
593 		case IIO_EV_DIR_RISING:
594 			return sx9360_write_far_debounce(data, val);
595 		case IIO_EV_DIR_FALLING:
596 			return sx9360_write_close_debounce(data, val);
597 		default:
598 			return -EINVAL;
599 		}
600 	case IIO_EV_INFO_HYSTERESIS:
601 		return sx9360_write_hysteresis(data, val);
602 	default:
603 		return -EINVAL;
604 	}
605 }
606 
sx9360_write_gain(struct sx_common_data * data,const struct iio_chan_spec * chan,int val)607 static int sx9360_write_gain(struct sx_common_data *data,
608 			     const struct iio_chan_spec *chan, int val)
609 {
610 	unsigned int gain, reg;
611 
612 	gain = ilog2(val);
613 	reg = SX9360_REG_PROX_CTRL0_PHR + chan->channel;
614 	gain = FIELD_PREP(SX9360_REG_PROX_CTRL0_GAIN_MASK, gain);
615 
616 	guard(mutex)(&data->mutex);
617 	return regmap_update_bits(data->regmap, reg,
618 				  SX9360_REG_PROX_CTRL0_GAIN_MASK,
619 				  gain);
620 }
621 
sx9360_write_raw(struct iio_dev * indio_dev,const struct iio_chan_spec * chan,int val,int val2,long mask)622 static int sx9360_write_raw(struct iio_dev *indio_dev,
623 			    const struct iio_chan_spec *chan, int val, int val2,
624 			    long mask)
625 {
626 	struct sx_common_data *data = iio_priv(indio_dev);
627 
628 	switch (mask) {
629 	case IIO_CHAN_INFO_SAMP_FREQ:
630 		return sx9360_set_samp_freq(data, val, val2);
631 	case IIO_CHAN_INFO_HARDWAREGAIN:
632 		return sx9360_write_gain(data, chan, val);
633 	default:
634 		return -EINVAL;
635 	}
636 }
637 
638 static const struct sx_common_reg_default sx9360_default_regs[] = {
639 	{ SX9360_REG_IRQ_MSK, 0x00 },
640 	{ SX9360_REG_IRQ_CFG, 0x00, "irq_cfg" },
641 	/*
642 	 * The lower 2 bits should not be set as it enable sensors measurements.
643 	 * Turning the detection on before the configuration values are set to
644 	 * good values can cause the device to return erroneous readings.
645 	 */
646 	{ SX9360_REG_GNRL_CTRL0, 0x00, "gnrl_ctrl0" },
647 	{ SX9360_REG_GNRL_CTRL1, 0x00, "gnrl_ctrl1" },
648 	{ SX9360_REG_GNRL_CTRL2, SX9360_REG_GNRL_CTRL2_PERIOD_102MS, "gnrl_ctrl2" },
649 
650 	{ SX9360_REG_AFE_CTRL1, SX9360_REG_AFE_CTRL1_RESFILTIN_0OHMS, "afe_ctrl0" },
651 	{ SX9360_REG_AFE_PARAM0_PHR, SX9360_REG_AFE_PARAM0_RSVD |
652 		SX9360_REG_AFE_PARAM0_RESOLUTION_128, "afe_param0_phr" },
653 	{ SX9360_REG_AFE_PARAM1_PHR, SX9360_REG_AFE_PARAM1_AGAIN_PHM_6PF |
654 		SX9360_REG_AFE_PARAM1_FREQ_83_33HZ, "afe_param1_phr" },
655 	{ SX9360_REG_AFE_PARAM0_PHM, SX9360_REG_AFE_PARAM0_RSVD |
656 		SX9360_REG_AFE_PARAM0_RESOLUTION_128, "afe_param0_phm" },
657 	{ SX9360_REG_AFE_PARAM1_PHM, SX9360_REG_AFE_PARAM1_AGAIN_PHM_6PF |
658 		SX9360_REG_AFE_PARAM1_FREQ_83_33HZ, "afe_param1_phm" },
659 
660 	{ SX9360_REG_PROX_CTRL0_PHR, SX9360_REG_PROX_CTRL0_GAIN_1 |
661 		SX9360_REG_PROX_CTRL0_RAWFILT_1P50, "prox_ctrl0_phr" },
662 	{ SX9360_REG_PROX_CTRL0_PHM, SX9360_REG_PROX_CTRL0_GAIN_1 |
663 		SX9360_REG_PROX_CTRL0_RAWFILT_1P50, "prox_ctrl0_phm" },
664 	{ SX9360_REG_PROX_CTRL1, SX9360_REG_PROX_CTRL1_AVGNEG_THRESH_16K, "prox_ctrl1" },
665 	{ SX9360_REG_PROX_CTRL2, SX9360_REG_PROX_CTRL2_AVGDEB_2SAMPLES |
666 		SX9360_REG_PROX_CTRL2_AVGPOS_THRESH_16K, "prox_ctrl2" },
667 	{ SX9360_REG_PROX_CTRL3, SX9360_REG_PROX_CTRL3_AVGNEG_FILT_2 |
668 		SX9360_REG_PROX_CTRL3_AVGPOS_FILT_256, "prox_ctrl3" },
669 	{ SX9360_REG_PROX_CTRL4, 0x00, "prox_ctrl4" },
670 	{ SX9360_REG_PROX_CTRL5, SX9360_REG_PROX_CTRL5_PROXTHRESH_32, "prox_ctrl5" },
671 };
672 
673 /* Activate all channels and perform an initial compensation. */
sx9360_init_compensation(struct iio_dev * indio_dev)674 static int sx9360_init_compensation(struct iio_dev *indio_dev)
675 {
676 	struct sx_common_data *data = iio_priv(indio_dev);
677 	unsigned int val;
678 	int ret;
679 
680 	/* run the compensation phase on all channels */
681 	ret = regmap_set_bits(data->regmap, SX9360_REG_STAT,
682 			      SX9360_REG_STAT_COMPSTAT_MASK);
683 	if (ret)
684 		return ret;
685 
686 	return regmap_read_poll_timeout(data->regmap, SX9360_REG_STAT, val,
687 				       !(val & SX9360_REG_STAT_COMPSTAT_MASK),
688 				       20000, 2000000);
689 }
690 
691 static const struct sx_common_reg_default *
sx9360_get_default_reg(struct device * dev,int idx,struct sx_common_reg_default * reg_def)692 sx9360_get_default_reg(struct device *dev, int idx,
693 		       struct sx_common_reg_default *reg_def)
694 {
695 	u32 raw = 0, pos = 0;
696 	int ret;
697 
698 	memcpy(reg_def, &sx9360_default_regs[idx], sizeof(*reg_def));
699 	switch (reg_def->reg) {
700 	case SX9360_REG_AFE_CTRL1:
701 		ret = device_property_read_u32(dev,
702 				"semtech,input-precharge-resistor-ohms",
703 				&raw);
704 		if (ret)
705 			break;
706 
707 		reg_def->def &= ~SX9360_REG_AFE_CTRL1_RESFILTIN_MASK;
708 		reg_def->def |= FIELD_PREP(SX9360_REG_AFE_CTRL1_RESFILTIN_MASK,
709 					   raw / 2000);
710 		break;
711 	case SX9360_REG_AFE_PARAM0_PHR:
712 	case SX9360_REG_AFE_PARAM0_PHM:
713 		ret = device_property_read_u32(dev, "semtech,resolution", &raw);
714 		if (ret)
715 			break;
716 
717 		raw = ilog2(raw) - 3;
718 
719 		reg_def->def &= ~SX9360_REG_AFE_PARAM0_RESOLUTION_MASK;
720 		reg_def->def |= FIELD_PREP(SX9360_REG_AFE_PARAM0_RESOLUTION_MASK, raw);
721 		break;
722 	case SX9360_REG_PROX_CTRL0_PHR:
723 	case SX9360_REG_PROX_CTRL0_PHM:
724 		ret = device_property_read_u32(dev, "semtech,proxraw-strength", &raw);
725 		if (ret)
726 			break;
727 
728 		reg_def->def &= ~SX9360_REG_PROX_CTRL0_RAWFILT_MASK;
729 		reg_def->def |= FIELD_PREP(SX9360_REG_PROX_CTRL0_RAWFILT_MASK, raw);
730 		break;
731 	case SX9360_REG_PROX_CTRL3:
732 		ret = device_property_read_u32(dev, "semtech,avg-pos-strength",
733 					       &pos);
734 		if (ret)
735 			break;
736 
737 		/* Powers of 2, except for a gap between 16 and 64 */
738 		raw = clamp(ilog2(pos), 3, 11) - (pos >= 32 ? 4 : 3);
739 		reg_def->def &= ~SX9360_REG_PROX_CTRL3_AVGPOS_FILT_MASK;
740 		reg_def->def |= FIELD_PREP(SX9360_REG_PROX_CTRL3_AVGPOS_FILT_MASK, raw);
741 		break;
742 	}
743 
744 	return reg_def;
745 }
746 
sx9360_check_whoami(struct device * dev,struct iio_dev * indio_dev)747 static int sx9360_check_whoami(struct device *dev, struct iio_dev *indio_dev)
748 {
749 	/*
750 	 * Only one sensor for this driver. Assuming the device tree
751 	 * is correct, just set the sensor name.
752 	 */
753 	indio_dev->name = "sx9360";
754 	return 0;
755 }
756 
757 static const struct sx_common_chip_info sx9360_chip_info = {
758 	.reg_stat = SX9360_REG_STAT,
759 	.reg_irq_msk = SX9360_REG_IRQ_MSK,
760 	.reg_enable_chan = SX9360_REG_GNRL_CTRL0,
761 	.reg_reset = SX9360_REG_RESET,
762 
763 	.mask_enable_chan = SX9360_REG_GNRL_CTRL0_PHEN_MASK,
764 	.stat_offset = 2,
765 	.num_channels = SX9360_NUM_CHANNELS,
766 	.num_default_regs = ARRAY_SIZE(sx9360_default_regs),
767 
768 	.ops = {
769 		.read_prox_data = sx9360_read_prox_data,
770 		.check_whoami = sx9360_check_whoami,
771 		.init_compensation = sx9360_init_compensation,
772 		.wait_for_sample = sx9360_wait_for_sample,
773 		.get_default_reg = sx9360_get_default_reg,
774 	},
775 
776 	.iio_channels = sx9360_channels,
777 	.num_iio_channels = ARRAY_SIZE(sx9360_channels),
778 	.iio_info =  {
779 		.read_raw = sx9360_read_raw,
780 		.read_avail = sx9360_read_avail,
781 		.read_label = sx9360_read_label,
782 		.read_event_value = sx9360_read_event_val,
783 		.write_event_value = sx9360_write_event_val,
784 		.write_raw = sx9360_write_raw,
785 		.read_event_config = sx_common_read_event_config,
786 		.write_event_config = sx_common_write_event_config,
787 	},
788 };
789 
sx9360_probe(struct i2c_client * client)790 static int sx9360_probe(struct i2c_client *client)
791 {
792 	return sx_common_probe(client, &sx9360_chip_info, &sx9360_regmap_config);
793 }
794 
sx9360_suspend(struct device * dev)795 static int sx9360_suspend(struct device *dev)
796 {
797 	struct sx_common_data *data = iio_priv(dev_get_drvdata(dev));
798 	unsigned int regval;
799 	int ret;
800 
801 	disable_irq_nosync(data->client->irq);
802 
803 	guard(mutex)(&data->mutex);
804 	ret = regmap_read(data->regmap, SX9360_REG_GNRL_CTRL0, &regval);
805 	if (ret < 0)
806 		return ret;
807 
808 	data->suspend_ctrl =
809 		FIELD_GET(SX9360_REG_GNRL_CTRL0_PHEN_MASK, regval);
810 
811 
812 	/* Disable all phases, send the device to sleep. */
813 	return regmap_write(data->regmap, SX9360_REG_GNRL_CTRL0, 0);
814 }
815 
sx9360_resume(struct device * dev)816 static int sx9360_resume(struct device *dev)
817 {
818 	struct sx_common_data *data = iio_priv(dev_get_drvdata(dev));
819 
820 	scoped_guard(mutex, &data->mutex) {
821 		int ret = regmap_update_bits(data->regmap,
822 					     SX9360_REG_GNRL_CTRL0,
823 					     SX9360_REG_GNRL_CTRL0_PHEN_MASK,
824 					     data->suspend_ctrl);
825 		if (ret)
826 			return ret;
827 	}
828 	enable_irq(data->client->irq);
829 	return 0;
830 }
831 
832 static DEFINE_SIMPLE_DEV_PM_OPS(sx9360_pm_ops, sx9360_suspend, sx9360_resume);
833 
834 static const struct acpi_device_id sx9360_acpi_match[] = {
835 	{ "STH9360", SX9360_WHOAMI_VALUE },
836 	{ "SAMM0208", SX9360_WHOAMI_VALUE },
837 	{ }
838 };
839 MODULE_DEVICE_TABLE(acpi, sx9360_acpi_match);
840 
841 static const struct of_device_id sx9360_of_match[] = {
842 	{ .compatible = "semtech,sx9360", (void *)SX9360_WHOAMI_VALUE },
843 	{ }
844 };
845 MODULE_DEVICE_TABLE(of, sx9360_of_match);
846 
847 static const struct i2c_device_id sx9360_id[] = {
848 	{"sx9360", SX9360_WHOAMI_VALUE },
849 	{ }
850 };
851 MODULE_DEVICE_TABLE(i2c, sx9360_id);
852 
853 static struct i2c_driver sx9360_driver = {
854 	.driver = {
855 		.name	= "sx9360",
856 		.acpi_match_table = sx9360_acpi_match,
857 		.of_match_table = sx9360_of_match,
858 		.pm = pm_sleep_ptr(&sx9360_pm_ops),
859 
860 		/*
861 		 * Lots of i2c transfers in probe + over 200 ms waiting in
862 		 * sx9360_init_compensation() mean a slow probe; prefer async
863 		 * so we don't delay boot if we're builtin to the kernel.
864 		 */
865 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
866 	},
867 	.probe		= sx9360_probe,
868 	.id_table	= sx9360_id,
869 };
870 module_i2c_driver(sx9360_driver);
871 
872 MODULE_AUTHOR("Gwendal Grignou <gwendal@chromium.org>");
873 MODULE_DESCRIPTION("Driver for Semtech SX9360 proximity sensor");
874 MODULE_LICENSE("GPL v2");
875 MODULE_IMPORT_NS("SEMTECH_PROX");
876