xref: /openbmc/linux/drivers/iio/light/si1133.c (revision a44e4f3a)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * si1133.c - Support for Silabs SI1133 combined ambient
4  * light and UV index sensors
5  *
6  * Copyright 2018 Maxime Roussin-Belanger <maxime.roussinbelanger@gmail.com>
7  */
8 
9 #include <linux/delay.h>
10 #include <linux/i2c.h>
11 #include <linux/interrupt.h>
12 #include <linux/module.h>
13 #include <linux/regmap.h>
14 
15 #include <linux/iio/iio.h>
16 #include <linux/iio/sysfs.h>
17 
18 #include <linux/util_macros.h>
19 
20 #define SI1133_REG_PART_ID		0x00
21 #define SI1133_REG_REV_ID		0x01
22 #define SI1133_REG_MFR_ID		0x02
23 #define SI1133_REG_INFO0		0x03
24 #define SI1133_REG_INFO1		0x04
25 
26 #define SI1133_PART_ID			0x33
27 
28 #define SI1133_REG_HOSTIN0		0x0A
29 #define SI1133_REG_COMMAND		0x0B
30 #define SI1133_REG_IRQ_ENABLE		0x0F
31 #define SI1133_REG_RESPONSE1		0x10
32 #define SI1133_REG_RESPONSE0		0x11
33 #define SI1133_REG_IRQ_STATUS		0x12
34 #define SI1133_REG_MEAS_RATE		0x1A
35 
36 #define SI1133_IRQ_CHANNEL_ENABLE	0xF
37 
38 #define SI1133_CMD_RESET_CTR		0x00
39 #define SI1133_CMD_RESET_SW		0x01
40 #define SI1133_CMD_FORCE		0x11
41 #define SI1133_CMD_START_AUTONOMOUS	0x13
42 #define SI1133_CMD_PARAM_SET		0x80
43 #define SI1133_CMD_PARAM_QUERY		0x40
44 #define SI1133_CMD_PARAM_MASK		0x3F
45 
46 #define SI1133_CMD_ERR_MASK		BIT(4)
47 #define SI1133_CMD_SEQ_MASK		0xF
48 #define SI1133_MAX_CMD_CTR		0xF
49 
50 #define SI1133_PARAM_REG_CHAN_LIST	0x01
51 #define SI1133_PARAM_REG_ADCCONFIG(x)	((x) * 4) + 2
52 #define SI1133_PARAM_REG_ADCSENS(x)	((x) * 4) + 3
53 #define SI1133_PARAM_REG_ADCPOST(x)	((x) * 4) + 4
54 
55 #define SI1133_ADCMUX_MASK 0x1F
56 
57 #define SI1133_ADCCONFIG_DECIM_RATE(x)	(x) << 5
58 
59 #define SI1133_ADCSENS_SCALE_MASK 0x70
60 #define SI1133_ADCSENS_SCALE_SHIFT 4
61 #define SI1133_ADCSENS_HSIG_MASK BIT(7)
62 #define SI1133_ADCSENS_HSIG_SHIFT 7
63 #define SI1133_ADCSENS_HW_GAIN_MASK 0xF
64 #define SI1133_ADCSENS_NB_MEAS(x)	fls(x) << SI1133_ADCSENS_SCALE_SHIFT
65 
66 #define SI1133_ADCPOST_24BIT_EN BIT(6)
67 #define SI1133_ADCPOST_POSTSHIFT_BITQTY(x) (x & GENMASK(2, 0)) << 3
68 
69 #define SI1133_PARAM_ADCMUX_SMALL_IR	0x0
70 #define SI1133_PARAM_ADCMUX_MED_IR	0x1
71 #define SI1133_PARAM_ADCMUX_LARGE_IR	0x2
72 #define SI1133_PARAM_ADCMUX_WHITE	0xB
73 #define SI1133_PARAM_ADCMUX_LARGE_WHITE	0xD
74 #define SI1133_PARAM_ADCMUX_UV		0x18
75 #define SI1133_PARAM_ADCMUX_UV_DEEP	0x19
76 
77 #define SI1133_ERR_INVALID_CMD		0x0
78 #define SI1133_ERR_INVALID_LOCATION_CMD 0x1
79 #define SI1133_ERR_SATURATION_ADC_OR_OVERFLOW_ACCUMULATION 0x2
80 #define SI1133_ERR_OUTPUT_BUFFER_OVERFLOW 0x3
81 
82 #define SI1133_COMPLETION_TIMEOUT_MS	500
83 
84 #define SI1133_CMD_MINSLEEP_US_LOW	5000
85 #define SI1133_CMD_MINSLEEP_US_HIGH	7500
86 #define SI1133_CMD_TIMEOUT_MS		25
87 #define SI1133_CMD_LUX_TIMEOUT_MS	5000
88 #define SI1133_CMD_TIMEOUT_US		SI1133_CMD_TIMEOUT_MS * 1000
89 
90 #define SI1133_REG_HOSTOUT(x)		(x) + 0x13
91 
92 #define SI1133_MEASUREMENT_FREQUENCY 1250
93 
94 #define SI1133_X_ORDER_MASK            0x0070
95 #define SI1133_Y_ORDER_MASK            0x0007
96 #define si1133_get_x_order(m)          ((m) & SI1133_X_ORDER_MASK) >> 4
97 #define si1133_get_y_order(m)          ((m) & SI1133_Y_ORDER_MASK)
98 
99 #define SI1133_LUX_ADC_MASK		0xE
100 #define SI1133_ADC_THRESHOLD		16000
101 #define SI1133_INPUT_FRACTION_HIGH	7
102 #define SI1133_INPUT_FRACTION_LOW	15
103 #define SI1133_LUX_OUTPUT_FRACTION	12
104 #define SI1133_LUX_BUFFER_SIZE		9
105 
106 static const int si1133_scale_available[] = {
107 	1, 2, 4, 8, 16, 32, 64, 128};
108 
109 static IIO_CONST_ATTR(scale_available, "1 2 4 8 16 32 64 128");
110 
111 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.0244 0.0488 0.0975 0.195 0.390 0.780 "
112 				     "1.560 3.120 6.24 12.48 25.0 50.0");
113 
114 /* A.K.A. HW_GAIN in datasheet */
115 enum si1133_int_time {
116 	    _24_4_us = 0,
117 	    _48_8_us = 1,
118 	    _97_5_us = 2,
119 	   _195_0_us = 3,
120 	   _390_0_us = 4,
121 	   _780_0_us = 5,
122 	 _1_560_0_us = 6,
123 	 _3_120_0_us = 7,
124 	 _6_240_0_us = 8,
125 	_12_480_0_us = 9,
126 	_25_ms = 10,
127 	_50_ms = 11,
128 };
129 
130 /* Integration time in milliseconds, nanoseconds */
131 static const int si1133_int_time_table[][2] = {
132 	[_24_4_us] = {0, 24400},
133 	[_48_8_us] = {0, 48800},
134 	[_97_5_us] = {0, 97500},
135 	[_195_0_us] = {0, 195000},
136 	[_390_0_us] = {0, 390000},
137 	[_780_0_us] = {0, 780000},
138 	[_1_560_0_us] = {1, 560000},
139 	[_3_120_0_us] = {3, 120000},
140 	[_6_240_0_us] = {6, 240000},
141 	[_12_480_0_us] = {12, 480000},
142 	[_25_ms] = {25, 000000},
143 	[_50_ms] = {50, 000000},
144 };
145 
146 static const struct regmap_range si1133_reg_ranges[] = {
147 	regmap_reg_range(0x00, 0x02),
148 	regmap_reg_range(0x0A, 0x0B),
149 	regmap_reg_range(0x0F, 0x0F),
150 	regmap_reg_range(0x10, 0x12),
151 	regmap_reg_range(0x13, 0x2C),
152 };
153 
154 static const struct regmap_range si1133_reg_ro_ranges[] = {
155 	regmap_reg_range(0x00, 0x02),
156 	regmap_reg_range(0x10, 0x2C),
157 };
158 
159 static const struct regmap_range si1133_precious_ranges[] = {
160 	regmap_reg_range(0x12, 0x12),
161 };
162 
163 static const struct regmap_access_table si1133_write_ranges_table = {
164 	.yes_ranges	= si1133_reg_ranges,
165 	.n_yes_ranges	= ARRAY_SIZE(si1133_reg_ranges),
166 	.no_ranges	= si1133_reg_ro_ranges,
167 	.n_no_ranges	= ARRAY_SIZE(si1133_reg_ro_ranges),
168 };
169 
170 static const struct regmap_access_table si1133_read_ranges_table = {
171 	.yes_ranges	= si1133_reg_ranges,
172 	.n_yes_ranges	= ARRAY_SIZE(si1133_reg_ranges),
173 };
174 
175 static const struct regmap_access_table si1133_precious_table = {
176 	.yes_ranges	= si1133_precious_ranges,
177 	.n_yes_ranges	= ARRAY_SIZE(si1133_precious_ranges),
178 };
179 
180 static const struct regmap_config si1133_regmap_config = {
181 	.reg_bits = 8,
182 	.val_bits = 8,
183 
184 	.max_register = 0x2C,
185 
186 	.wr_table = &si1133_write_ranges_table,
187 	.rd_table = &si1133_read_ranges_table,
188 
189 	.precious_table = &si1133_precious_table,
190 };
191 
192 struct si1133_data {
193 	struct regmap *regmap;
194 	struct i2c_client *client;
195 
196 	/* Lock protecting one command at a time can be processed */
197 	struct mutex mutex;
198 
199 	int rsp_seq;
200 	u8 scan_mask;
201 	u8 adc_sens[6];
202 	u8 adc_config[6];
203 
204 	struct completion completion;
205 };
206 
207 struct si1133_coeff {
208 	s16 info;
209 	u16 mag;
210 };
211 
212 struct si1133_lux_coeff {
213 	struct si1133_coeff coeff_high[4];
214 	struct si1133_coeff coeff_low[9];
215 };
216 
217 static const struct si1133_lux_coeff lux_coeff = {
218 	{
219 		{  0,   209},
220 		{ 1665,  93},
221 		{ 2064,  65},
222 		{-2671, 234}
223 	},
224 	{
225 		{    0,     0},
226 		{ 1921, 29053},
227 		{-1022, 36363},
228 		{ 2320, 20789},
229 		{ -367, 57909},
230 		{-1774, 38240},
231 		{ -608, 46775},
232 		{-1503, 51831},
233 		{-1886, 58928}
234 	}
235 };
236 
237 static int si1133_calculate_polynomial_inner(u32 input, u8 fraction, u16 mag,
238 					     s8 shift)
239 {
240 	return ((input << fraction) / mag) << shift;
241 }
242 
243 static int si1133_calculate_output(u32 x, u32 y, u8 x_order, u8 y_order,
244 				   u8 input_fraction, s8 sign,
245 				   const struct si1133_coeff *coeffs)
246 {
247 	s8 shift;
248 	int x1 = 1;
249 	int x2 = 1;
250 	int y1 = 1;
251 	int y2 = 1;
252 
253 	shift = ((u16)coeffs->info & 0xFF00) >> 8;
254 	shift ^= 0xFF;
255 	shift += 1;
256 	shift = -shift;
257 
258 	if (x_order > 0) {
259 		x1 = si1133_calculate_polynomial_inner(x, input_fraction,
260 						       coeffs->mag, shift);
261 		if (x_order > 1)
262 			x2 = x1;
263 	}
264 
265 	if (y_order > 0) {
266 		y1 = si1133_calculate_polynomial_inner(y, input_fraction,
267 						       coeffs->mag, shift);
268 		if (y_order > 1)
269 			y2 = y1;
270 	}
271 
272 	return sign * x1 * x2 * y1 * y2;
273 }
274 
275 /*
276  * The algorithm is from:
277  * https://siliconlabs.github.io/Gecko_SDK_Doc/efm32zg/html/si1133_8c_source.html#l00716
278  */
279 static int si1133_calc_polynomial(u32 x, u32 y, u8 input_fraction, u8 num_coeff,
280 				  const struct si1133_coeff *coeffs)
281 {
282 	u8 x_order, y_order;
283 	u8 counter;
284 	s8 sign;
285 	int output = 0;
286 
287 	for (counter = 0; counter < num_coeff; counter++) {
288 		if (coeffs->info < 0)
289 			sign = -1;
290 		else
291 			sign = 1;
292 
293 		x_order = si1133_get_x_order(coeffs->info);
294 		y_order = si1133_get_y_order(coeffs->info);
295 
296 		if ((x_order == 0) && (y_order == 0))
297 			output +=
298 			       sign * coeffs->mag << SI1133_LUX_OUTPUT_FRACTION;
299 		else
300 			output += si1133_calculate_output(x, y, x_order,
301 							  y_order,
302 							  input_fraction, sign,
303 							  coeffs);
304 		coeffs++;
305 	}
306 
307 	return abs(output);
308 }
309 
310 static int si1133_cmd_reset_sw(struct si1133_data *data)
311 {
312 	struct device *dev = &data->client->dev;
313 	unsigned int resp;
314 	unsigned long timeout;
315 	int err;
316 
317 	err = regmap_write(data->regmap, SI1133_REG_COMMAND,
318 			   SI1133_CMD_RESET_SW);
319 	if (err)
320 		return err;
321 
322 	timeout = jiffies + msecs_to_jiffies(SI1133_CMD_TIMEOUT_MS);
323 	while (true) {
324 		err = regmap_read(data->regmap, SI1133_REG_RESPONSE0, &resp);
325 		if (err == -ENXIO) {
326 			usleep_range(SI1133_CMD_MINSLEEP_US_LOW,
327 				     SI1133_CMD_MINSLEEP_US_HIGH);
328 			continue;
329 		}
330 
331 		if ((resp & SI1133_MAX_CMD_CTR) == SI1133_MAX_CMD_CTR)
332 			break;
333 
334 		if (time_after(jiffies, timeout)) {
335 			dev_warn(dev, "Timeout on reset ctr resp: %d\n", resp);
336 			return -ETIMEDOUT;
337 		}
338 	}
339 
340 	if (!err)
341 		data->rsp_seq = SI1133_MAX_CMD_CTR;
342 
343 	return err;
344 }
345 
346 static int si1133_parse_response_err(struct device *dev, u32 resp, u8 cmd)
347 {
348 	resp &= 0xF;
349 
350 	switch (resp) {
351 	case SI1133_ERR_OUTPUT_BUFFER_OVERFLOW:
352 		dev_warn(dev, "Output buffer overflow: %#02hhx\n", cmd);
353 		return -EOVERFLOW;
354 	case SI1133_ERR_SATURATION_ADC_OR_OVERFLOW_ACCUMULATION:
355 		dev_warn(dev, "Saturation of the ADC or overflow of accumulation: %#02hhx\n",
356 			 cmd);
357 		return -EOVERFLOW;
358 	case SI1133_ERR_INVALID_LOCATION_CMD:
359 		dev_warn(dev,
360 			 "Parameter access to an invalid location: %#02hhx\n",
361 			 cmd);
362 		return -EINVAL;
363 	case SI1133_ERR_INVALID_CMD:
364 		dev_warn(dev, "Invalid command %#02hhx\n", cmd);
365 		return -EINVAL;
366 	default:
367 		dev_warn(dev, "Unknown error %#02hhx\n", cmd);
368 		return -EINVAL;
369 	}
370 }
371 
372 static int si1133_cmd_reset_counter(struct si1133_data *data)
373 {
374 	int err = regmap_write(data->regmap, SI1133_REG_COMMAND,
375 			       SI1133_CMD_RESET_CTR);
376 	if (err)
377 		return err;
378 
379 	data->rsp_seq = 0;
380 
381 	return 0;
382 }
383 
384 static int si1133_command(struct si1133_data *data, u8 cmd)
385 {
386 	struct device *dev = &data->client->dev;
387 	u32 resp;
388 	int err;
389 	int expected_seq;
390 
391 	mutex_lock(&data->mutex);
392 
393 	expected_seq = (data->rsp_seq + 1) & SI1133_MAX_CMD_CTR;
394 
395 	if (cmd == SI1133_CMD_FORCE)
396 		reinit_completion(&data->completion);
397 
398 	err = regmap_write(data->regmap, SI1133_REG_COMMAND, cmd);
399 	if (err) {
400 		dev_warn(dev, "Failed to write command %#02hhx, ret=%d\n", cmd,
401 			 err);
402 		goto out;
403 	}
404 
405 	if (cmd == SI1133_CMD_FORCE) {
406 		/* wait for irq */
407 		if (!wait_for_completion_timeout(&data->completion,
408 			msecs_to_jiffies(SI1133_COMPLETION_TIMEOUT_MS))) {
409 			err = -ETIMEDOUT;
410 			goto out;
411 		}
412 		err = regmap_read(data->regmap, SI1133_REG_RESPONSE0, &resp);
413 		if (err)
414 			goto out;
415 	} else {
416 		err = regmap_read_poll_timeout(data->regmap,
417 					       SI1133_REG_RESPONSE0, resp,
418 					       (resp & SI1133_CMD_SEQ_MASK) ==
419 					       expected_seq ||
420 					       (resp & SI1133_CMD_ERR_MASK),
421 					       SI1133_CMD_MINSLEEP_US_LOW,
422 					       SI1133_CMD_TIMEOUT_MS * 1000);
423 		if (err) {
424 			dev_warn(dev,
425 				 "Failed to read command %#02hhx, ret=%d\n",
426 				 cmd, err);
427 			goto out;
428 		}
429 	}
430 
431 	if (resp & SI1133_CMD_ERR_MASK) {
432 		err = si1133_parse_response_err(dev, resp, cmd);
433 		si1133_cmd_reset_counter(data);
434 	} else {
435 		data->rsp_seq = expected_seq;
436 	}
437 
438 out:
439 	mutex_unlock(&data->mutex);
440 
441 	return err;
442 }
443 
444 static int si1133_param_set(struct si1133_data *data, u8 param, u32 value)
445 {
446 	int err = regmap_write(data->regmap, SI1133_REG_HOSTIN0, value);
447 
448 	if (err)
449 		return err;
450 
451 	return si1133_command(data, SI1133_CMD_PARAM_SET |
452 			      (param & SI1133_CMD_PARAM_MASK));
453 }
454 
455 static int si1133_param_query(struct si1133_data *data, u8 param, u32 *result)
456 {
457 	int err = si1133_command(data, SI1133_CMD_PARAM_QUERY |
458 				 (param & SI1133_CMD_PARAM_MASK));
459 	if (err)
460 		return err;
461 
462 	return regmap_read(data->regmap, SI1133_REG_RESPONSE1, result);
463 }
464 
465 #define SI1133_CHANNEL(_ch, _type) \
466 	.type = _type, \
467 	.channel = _ch, \
468 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
469 	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) | \
470 		BIT(IIO_CHAN_INFO_SCALE) | \
471 		BIT(IIO_CHAN_INFO_HARDWAREGAIN), \
472 
473 static const struct iio_chan_spec si1133_channels[] = {
474 	{
475 		.type = IIO_LIGHT,
476 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
477 		.channel = 0,
478 	},
479 	{
480 		SI1133_CHANNEL(SI1133_PARAM_ADCMUX_WHITE, IIO_INTENSITY)
481 		.channel2 = IIO_MOD_LIGHT_BOTH,
482 	},
483 	{
484 		SI1133_CHANNEL(SI1133_PARAM_ADCMUX_LARGE_WHITE, IIO_INTENSITY)
485 		.channel2 = IIO_MOD_LIGHT_BOTH,
486 		.extend_name = "large",
487 	},
488 	{
489 		SI1133_CHANNEL(SI1133_PARAM_ADCMUX_SMALL_IR, IIO_INTENSITY)
490 		.extend_name = "small",
491 		.modified = 1,
492 		.channel2 = IIO_MOD_LIGHT_IR,
493 	},
494 	{
495 		SI1133_CHANNEL(SI1133_PARAM_ADCMUX_MED_IR, IIO_INTENSITY)
496 		.modified = 1,
497 		.channel2 = IIO_MOD_LIGHT_IR,
498 	},
499 	{
500 		SI1133_CHANNEL(SI1133_PARAM_ADCMUX_LARGE_IR, IIO_INTENSITY)
501 		.extend_name = "large",
502 		.modified = 1,
503 		.channel2 = IIO_MOD_LIGHT_IR,
504 	},
505 	{
506 		SI1133_CHANNEL(SI1133_PARAM_ADCMUX_UV, IIO_UVINDEX)
507 	},
508 	{
509 		SI1133_CHANNEL(SI1133_PARAM_ADCMUX_UV_DEEP, IIO_UVINDEX)
510 		.modified = 1,
511 		.channel2 = IIO_MOD_LIGHT_DUV,
512 	}
513 };
514 
515 static int si1133_get_int_time_index(int milliseconds, int nanoseconds)
516 {
517 	int i;
518 
519 	for (i = 0; i < ARRAY_SIZE(si1133_int_time_table); i++) {
520 		if (milliseconds == si1133_int_time_table[i][0] &&
521 		    nanoseconds == si1133_int_time_table[i][1])
522 			return i;
523 	}
524 	return -EINVAL;
525 }
526 
527 static int si1133_set_integration_time(struct si1133_data *data, u8 adc,
528 				       int milliseconds, int nanoseconds)
529 {
530 	int index;
531 
532 	index = si1133_get_int_time_index(milliseconds, nanoseconds);
533 	if (index < 0)
534 		return index;
535 
536 	data->adc_sens[adc] &= 0xF0;
537 	data->adc_sens[adc] |= index;
538 
539 	return si1133_param_set(data, SI1133_PARAM_REG_ADCSENS(0),
540 				data->adc_sens[adc]);
541 }
542 
543 static int si1133_set_chlist(struct si1133_data *data, u8 scan_mask)
544 {
545 	/* channel list already set, no need to reprogram */
546 	if (data->scan_mask == scan_mask)
547 		return 0;
548 
549 	data->scan_mask = scan_mask;
550 
551 	return si1133_param_set(data, SI1133_PARAM_REG_CHAN_LIST, scan_mask);
552 }
553 
554 static int si1133_chan_set_adcconfig(struct si1133_data *data, u8 adc,
555 				     u8 adc_config)
556 {
557 	int err;
558 
559 	err = si1133_param_set(data, SI1133_PARAM_REG_ADCCONFIG(adc),
560 			       adc_config);
561 	if (err)
562 		return err;
563 
564 	data->adc_config[adc] = adc_config;
565 
566 	return 0;
567 }
568 
569 static int si1133_update_adcconfig(struct si1133_data *data, uint8_t adc,
570 				   u8 mask, u8 shift, u8 value)
571 {
572 	u32 adc_config;
573 	int err;
574 
575 	err = si1133_param_query(data, SI1133_PARAM_REG_ADCCONFIG(adc),
576 				 &adc_config);
577 	if (err)
578 		return err;
579 
580 	adc_config &= ~mask;
581 	adc_config |= (value << shift);
582 
583 	return si1133_chan_set_adcconfig(data, adc, adc_config);
584 }
585 
586 static int si1133_set_adcmux(struct si1133_data *data, u8 adc, u8 mux)
587 {
588 	if ((mux & data->adc_config[adc]) == mux)
589 		return 0; /* mux already set to correct value */
590 
591 	return si1133_update_adcconfig(data, adc, SI1133_ADCMUX_MASK, 0, mux);
592 }
593 
594 static int si1133_force_measurement(struct si1133_data *data)
595 {
596 	return si1133_command(data, SI1133_CMD_FORCE);
597 }
598 
599 static int si1133_bulk_read(struct si1133_data *data, u8 start_reg, u8 length,
600 			    u8 *buffer)
601 {
602 	int err;
603 
604 	err = si1133_force_measurement(data);
605 	if (err)
606 		return err;
607 
608 	return regmap_bulk_read(data->regmap, start_reg, buffer, length);
609 }
610 
611 static int si1133_measure(struct si1133_data *data,
612 			  struct iio_chan_spec const *chan,
613 			  int *val)
614 {
615 	int err;
616 
617 	__be16 resp;
618 
619 	err = si1133_set_adcmux(data, 0, chan->channel);
620 	if (err)
621 		return err;
622 
623 	/* Deactivate lux measurements if they were active */
624 	err = si1133_set_chlist(data, BIT(0));
625 	if (err)
626 		return err;
627 
628 	err = si1133_bulk_read(data, SI1133_REG_HOSTOUT(0), sizeof(resp),
629 			       (u8 *)&resp);
630 	if (err)
631 		return err;
632 
633 	*val = be16_to_cpu(resp);
634 
635 	return err;
636 }
637 
638 static irqreturn_t si1133_threaded_irq_handler(int irq, void *private)
639 {
640 	struct iio_dev *iio_dev = private;
641 	struct si1133_data *data = iio_priv(iio_dev);
642 	u32 irq_status;
643 	int err;
644 
645 	err = regmap_read(data->regmap, SI1133_REG_IRQ_STATUS, &irq_status);
646 	if (err) {
647 		dev_err_ratelimited(&iio_dev->dev, "Error reading IRQ\n");
648 		goto out;
649 	}
650 
651 	if (irq_status != data->scan_mask)
652 		return IRQ_NONE;
653 
654 out:
655 	complete(&data->completion);
656 
657 	return IRQ_HANDLED;
658 }
659 
660 static int si1133_scale_to_swgain(int scale_integer, int scale_fractional)
661 {
662 	scale_integer = find_closest(scale_integer, si1133_scale_available,
663 				     ARRAY_SIZE(si1133_scale_available));
664 	if (scale_integer < 0 ||
665 	    scale_integer > ARRAY_SIZE(si1133_scale_available) ||
666 	    scale_fractional != 0)
667 		return -EINVAL;
668 
669 	return scale_integer;
670 }
671 
672 static int si1133_chan_set_adcsens(struct si1133_data *data, u8 adc,
673 				   u8 adc_sens)
674 {
675 	int err;
676 
677 	err = si1133_param_set(data, SI1133_PARAM_REG_ADCSENS(adc), adc_sens);
678 	if (err)
679 		return err;
680 
681 	data->adc_sens[adc] = adc_sens;
682 
683 	return 0;
684 }
685 
686 static int si1133_update_adcsens(struct si1133_data *data, u8 mask,
687 				 u8 shift, u8 value)
688 {
689 	int err;
690 	u32 adc_sens;
691 
692 	err = si1133_param_query(data, SI1133_PARAM_REG_ADCSENS(0),
693 				 &adc_sens);
694 	if (err)
695 		return err;
696 
697 	adc_sens &= ~mask;
698 	adc_sens |= (value << shift);
699 
700 	return si1133_chan_set_adcsens(data, 0, adc_sens);
701 }
702 
703 static int si1133_get_lux(struct si1133_data *data, int *val)
704 {
705 	int err;
706 	int lux;
707 	u32 high_vis;
708 	u32 low_vis;
709 	u32 ir;
710 	u8 buffer[SI1133_LUX_BUFFER_SIZE];
711 
712 	/* Activate lux channels */
713 	err = si1133_set_chlist(data, SI1133_LUX_ADC_MASK);
714 	if (err)
715 		return err;
716 
717 	err = si1133_bulk_read(data, SI1133_REG_HOSTOUT(0),
718 			       SI1133_LUX_BUFFER_SIZE, buffer);
719 	if (err)
720 		return err;
721 
722 	high_vis = (buffer[0] << 16) | (buffer[1] << 8) | buffer[2];
723 	low_vis = (buffer[3] << 16) | (buffer[4] << 8) | buffer[5];
724 	ir = (buffer[6] << 16) | (buffer[7] << 8) | buffer[8];
725 
726 	if (high_vis > SI1133_ADC_THRESHOLD || ir > SI1133_ADC_THRESHOLD)
727 		lux = si1133_calc_polynomial(high_vis, ir,
728 					     SI1133_INPUT_FRACTION_HIGH,
729 					     ARRAY_SIZE(lux_coeff.coeff_high),
730 					     &lux_coeff.coeff_high[0]);
731 	else
732 		lux = si1133_calc_polynomial(low_vis, ir,
733 					     SI1133_INPUT_FRACTION_LOW,
734 					     ARRAY_SIZE(lux_coeff.coeff_low),
735 					     &lux_coeff.coeff_low[0]);
736 
737 	*val = lux >> SI1133_LUX_OUTPUT_FRACTION;
738 
739 	return err;
740 }
741 
742 static int si1133_read_raw(struct iio_dev *iio_dev,
743 			   struct iio_chan_spec const *chan,
744 			   int *val, int *val2, long mask)
745 {
746 	struct si1133_data *data = iio_priv(iio_dev);
747 	u8 adc_sens = data->adc_sens[0];
748 	int err;
749 
750 	switch (mask) {
751 	case IIO_CHAN_INFO_PROCESSED:
752 		switch (chan->type) {
753 		case IIO_LIGHT:
754 			err = si1133_get_lux(data, val);
755 			if (err)
756 				return err;
757 
758 			return IIO_VAL_INT;
759 		default:
760 			return -EINVAL;
761 		}
762 	case IIO_CHAN_INFO_RAW:
763 		switch (chan->type) {
764 		case IIO_INTENSITY:
765 		case IIO_UVINDEX:
766 			err = si1133_measure(data, chan, val);
767 			if (err)
768 				return err;
769 
770 			return IIO_VAL_INT;
771 		default:
772 			return -EINVAL;
773 		}
774 	case IIO_CHAN_INFO_INT_TIME:
775 		switch (chan->type) {
776 		case IIO_INTENSITY:
777 		case IIO_UVINDEX:
778 			adc_sens &= SI1133_ADCSENS_HW_GAIN_MASK;
779 
780 			*val = si1133_int_time_table[adc_sens][0];
781 			*val2 = si1133_int_time_table[adc_sens][1];
782 			return IIO_VAL_INT_PLUS_MICRO;
783 		default:
784 			return -EINVAL;
785 		}
786 	case IIO_CHAN_INFO_SCALE:
787 		switch (chan->type) {
788 		case IIO_INTENSITY:
789 		case IIO_UVINDEX:
790 			adc_sens &= SI1133_ADCSENS_SCALE_MASK;
791 			adc_sens >>= SI1133_ADCSENS_SCALE_SHIFT;
792 
793 			*val = BIT(adc_sens);
794 
795 			return IIO_VAL_INT;
796 		default:
797 			return -EINVAL;
798 		}
799 	case IIO_CHAN_INFO_HARDWAREGAIN:
800 		switch (chan->type) {
801 		case IIO_INTENSITY:
802 		case IIO_UVINDEX:
803 			adc_sens >>= SI1133_ADCSENS_HSIG_SHIFT;
804 
805 			*val = adc_sens;
806 
807 			return IIO_VAL_INT;
808 		default:
809 			return -EINVAL;
810 		}
811 	default:
812 		return -EINVAL;
813 	}
814 }
815 
816 static int si1133_write_raw(struct iio_dev *iio_dev,
817 			    struct iio_chan_spec const *chan,
818 			    int val, int val2, long mask)
819 {
820 	struct si1133_data *data = iio_priv(iio_dev);
821 
822 	switch (mask) {
823 	case IIO_CHAN_INFO_SCALE:
824 		switch (chan->type) {
825 		case IIO_INTENSITY:
826 		case IIO_UVINDEX:
827 			val = si1133_scale_to_swgain(val, val2);
828 			if (val < 0)
829 				return val;
830 
831 			return si1133_update_adcsens(data,
832 						     SI1133_ADCSENS_SCALE_MASK,
833 						     SI1133_ADCSENS_SCALE_SHIFT,
834 						     val);
835 		default:
836 			return -EINVAL;
837 		}
838 	case IIO_CHAN_INFO_INT_TIME:
839 		return si1133_set_integration_time(data, 0, val, val2);
840 	case IIO_CHAN_INFO_HARDWAREGAIN:
841 		switch (chan->type) {
842 		case IIO_INTENSITY:
843 		case IIO_UVINDEX:
844 			if (val != 0 && val != 1)
845 				return -EINVAL;
846 
847 			return si1133_update_adcsens(data,
848 						     SI1133_ADCSENS_HSIG_MASK,
849 						     SI1133_ADCSENS_HSIG_SHIFT,
850 						     val);
851 		default:
852 			return -EINVAL;
853 		}
854 	default:
855 		return -EINVAL;
856 	}
857 }
858 
859 static struct attribute *si1133_attributes[] = {
860 	&iio_const_attr_integration_time_available.dev_attr.attr,
861 	&iio_const_attr_scale_available.dev_attr.attr,
862 	NULL,
863 };
864 
865 static const struct attribute_group si1133_attribute_group = {
866 	.attrs = si1133_attributes,
867 };
868 
869 static const struct iio_info si1133_info = {
870 	.read_raw = si1133_read_raw,
871 	.write_raw = si1133_write_raw,
872 	.attrs = &si1133_attribute_group,
873 };
874 
875 /*
876  * si1133_init_lux_channels - Configure 3 different channels(adc) (1,2 and 3)
877  * The channel configuration for the lux measurement was taken from :
878  * https://siliconlabs.github.io/Gecko_SDK_Doc/efm32zg/html/si1133_8c_source.html#l00578
879  *
880  * Reserved the channel 0 for the other raw measurements
881  */
882 static int si1133_init_lux_channels(struct si1133_data *data)
883 {
884 	int err;
885 
886 	err = si1133_chan_set_adcconfig(data, 1,
887 					SI1133_ADCCONFIG_DECIM_RATE(1) |
888 					SI1133_PARAM_ADCMUX_LARGE_WHITE);
889 	if (err)
890 		return err;
891 
892 	err = si1133_param_set(data, SI1133_PARAM_REG_ADCPOST(1),
893 			       SI1133_ADCPOST_24BIT_EN |
894 			       SI1133_ADCPOST_POSTSHIFT_BITQTY(0));
895 	if (err)
896 		return err;
897 	err = si1133_chan_set_adcsens(data, 1, SI1133_ADCSENS_HSIG_MASK |
898 				      SI1133_ADCSENS_NB_MEAS(64) | _48_8_us);
899 	if (err)
900 		return err;
901 
902 	err = si1133_chan_set_adcconfig(data, 2,
903 					SI1133_ADCCONFIG_DECIM_RATE(1) |
904 					SI1133_PARAM_ADCMUX_LARGE_WHITE);
905 	if (err)
906 		return err;
907 
908 	err = si1133_param_set(data, SI1133_PARAM_REG_ADCPOST(2),
909 			       SI1133_ADCPOST_24BIT_EN |
910 			       SI1133_ADCPOST_POSTSHIFT_BITQTY(2));
911 	if (err)
912 		return err;
913 
914 	err = si1133_chan_set_adcsens(data, 2, SI1133_ADCSENS_HSIG_MASK |
915 				      SI1133_ADCSENS_NB_MEAS(1) | _3_120_0_us);
916 	if (err)
917 		return err;
918 
919 	err = si1133_chan_set_adcconfig(data, 3,
920 					SI1133_ADCCONFIG_DECIM_RATE(1) |
921 					SI1133_PARAM_ADCMUX_MED_IR);
922 	if (err)
923 		return err;
924 
925 	err = si1133_param_set(data, SI1133_PARAM_REG_ADCPOST(3),
926 			       SI1133_ADCPOST_24BIT_EN |
927 			       SI1133_ADCPOST_POSTSHIFT_BITQTY(2));
928 	if (err)
929 		return err;
930 
931 	return  si1133_chan_set_adcsens(data, 3, SI1133_ADCSENS_HSIG_MASK |
932 					SI1133_ADCSENS_NB_MEAS(64) | _48_8_us);
933 }
934 
935 static int si1133_initialize(struct si1133_data *data)
936 {
937 	int err;
938 
939 	err = si1133_cmd_reset_sw(data);
940 	if (err)
941 		return err;
942 
943 	/* Turn off autonomous mode */
944 	err = si1133_param_set(data, SI1133_REG_MEAS_RATE, 0);
945 	if (err)
946 		return err;
947 
948 	err = si1133_init_lux_channels(data);
949 	if (err)
950 		return err;
951 
952 	return regmap_write(data->regmap, SI1133_REG_IRQ_ENABLE,
953 			    SI1133_IRQ_CHANNEL_ENABLE);
954 }
955 
956 static int si1133_validate_ids(struct iio_dev *iio_dev)
957 {
958 	struct si1133_data *data = iio_priv(iio_dev);
959 
960 	unsigned int part_id, rev_id, mfr_id;
961 	int err;
962 
963 	err = regmap_read(data->regmap, SI1133_REG_PART_ID, &part_id);
964 	if (err)
965 		return err;
966 
967 	err = regmap_read(data->regmap, SI1133_REG_REV_ID, &rev_id);
968 	if (err)
969 		return err;
970 
971 	err = regmap_read(data->regmap, SI1133_REG_MFR_ID, &mfr_id);
972 	if (err)
973 		return err;
974 
975 	dev_info(&iio_dev->dev,
976 		 "Device ID part %#02hhx rev %#02hhx mfr %#02hhx\n",
977 		 part_id, rev_id, mfr_id);
978 	if (part_id != SI1133_PART_ID) {
979 		dev_err(&iio_dev->dev,
980 			"Part ID mismatch got %#02hhx, expected %#02x\n",
981 			part_id, SI1133_PART_ID);
982 		return -ENODEV;
983 	}
984 
985 	return 0;
986 }
987 
988 static int si1133_probe(struct i2c_client *client,
989 			const struct i2c_device_id *id)
990 {
991 	struct si1133_data *data;
992 	struct iio_dev *iio_dev;
993 	int err;
994 
995 	iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
996 	if (!iio_dev)
997 		return -ENOMEM;
998 
999 	data = iio_priv(iio_dev);
1000 
1001 	init_completion(&data->completion);
1002 
1003 	data->regmap = devm_regmap_init_i2c(client, &si1133_regmap_config);
1004 	if (IS_ERR(data->regmap)) {
1005 		err = PTR_ERR(data->regmap);
1006 		dev_err(&client->dev, "Failed to initialise regmap: %d\n", err);
1007 		return err;
1008 	}
1009 
1010 	i2c_set_clientdata(client, iio_dev);
1011 	data->client = client;
1012 
1013 	iio_dev->dev.parent = &client->dev;
1014 	iio_dev->name = id->name;
1015 	iio_dev->channels = si1133_channels;
1016 	iio_dev->num_channels = ARRAY_SIZE(si1133_channels);
1017 	iio_dev->info = &si1133_info;
1018 	iio_dev->modes = INDIO_DIRECT_MODE;
1019 
1020 	mutex_init(&data->mutex);
1021 
1022 	err = si1133_validate_ids(iio_dev);
1023 	if (err)
1024 		return err;
1025 
1026 	err = si1133_initialize(data);
1027 	if (err) {
1028 		dev_err(&client->dev,
1029 			"Error when initializing chip: %d\n", err);
1030 		return err;
1031 	}
1032 
1033 	if (!client->irq) {
1034 		dev_err(&client->dev,
1035 			"Required interrupt not provided, cannot proceed\n");
1036 		return -EINVAL;
1037 	}
1038 
1039 	err = devm_request_threaded_irq(&client->dev, client->irq,
1040 					NULL,
1041 					si1133_threaded_irq_handler,
1042 					IRQF_ONESHOT | IRQF_SHARED,
1043 					client->name, iio_dev);
1044 	if (err) {
1045 		dev_warn(&client->dev, "Request irq %d failed: %i\n",
1046 			 client->irq, err);
1047 		return err;
1048 	}
1049 
1050 	return devm_iio_device_register(&client->dev, iio_dev);
1051 }
1052 
1053 static const struct i2c_device_id si1133_ids[] = {
1054 	{ "si1133", 0 },
1055 	{ }
1056 };
1057 MODULE_DEVICE_TABLE(i2c, si1133_ids);
1058 
1059 static struct i2c_driver si1133_driver = {
1060 	.driver = {
1061 	    .name   = "si1133",
1062 	},
1063 	.probe  = si1133_probe,
1064 	.id_table = si1133_ids,
1065 };
1066 
1067 module_i2c_driver(si1133_driver);
1068 
1069 MODULE_AUTHOR("Maxime Roussin-Belanger <maxime.roussinbelanger@gmail.com>");
1070 MODULE_DESCRIPTION("Silabs SI1133, UV index sensor and ambient light sensor driver");
1071 MODULE_LICENSE("GPL");
1072