xref: /linux/drivers/iio/light/iqs621-als.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Azoteq IQS621/622 Ambient Light Sensors
4  *
5  * Copyright (C) 2019 Jeff LaBundy <jeff@labundy.com>
6  */
7 
8 #include <linux/device.h>
9 #include <linux/iio/events.h>
10 #include <linux/iio/iio.h>
11 #include <linux/kernel.h>
12 #include <linux/mfd/iqs62x.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/notifier.h>
16 #include <linux/platform_device.h>
17 #include <linux/regmap.h>
18 
19 #define IQS621_ALS_FLAGS_LIGHT			BIT(7)
20 #define IQS621_ALS_FLAGS_RANGE			GENMASK(3, 0)
21 
22 #define IQS621_ALS_UI_OUT			0x17
23 
24 #define IQS621_ALS_THRESH_DARK			0x80
25 #define IQS621_ALS_THRESH_LIGHT			0x81
26 
27 #define IQS622_IR_RANGE				0x15
28 #define IQS622_IR_FLAGS				0x16
29 #define IQS622_IR_FLAGS_TOUCH			BIT(1)
30 #define IQS622_IR_FLAGS_PROX			BIT(0)
31 
32 #define IQS622_IR_UI_OUT			0x17
33 
34 #define IQS622_IR_THRESH_PROX			0x91
35 #define IQS622_IR_THRESH_TOUCH			0x92
36 
37 struct iqs621_als_private {
38 	struct iqs62x_core *iqs62x;
39 	struct iio_dev *indio_dev;
40 	struct notifier_block notifier;
41 	struct mutex lock;
42 	bool light_en;
43 	bool range_en;
44 	bool prox_en;
45 	u8 als_flags;
46 	u8 ir_flags_mask;
47 	u8 ir_flags;
48 	u8 thresh_light;
49 	u8 thresh_dark;
50 	u8 thresh_prox;
51 };
52 
53 static int iqs621_als_init(struct iqs621_als_private *iqs621_als)
54 {
55 	struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
56 	unsigned int event_mask = 0;
57 	int ret;
58 
59 	switch (iqs621_als->ir_flags_mask) {
60 	case IQS622_IR_FLAGS_TOUCH:
61 		ret = regmap_write(iqs62x->regmap, IQS622_IR_THRESH_TOUCH,
62 				   iqs621_als->thresh_prox);
63 		break;
64 
65 	case IQS622_IR_FLAGS_PROX:
66 		ret = regmap_write(iqs62x->regmap, IQS622_IR_THRESH_PROX,
67 				   iqs621_als->thresh_prox);
68 		break;
69 
70 	default:
71 		ret = regmap_write(iqs62x->regmap, IQS621_ALS_THRESH_LIGHT,
72 				   iqs621_als->thresh_light);
73 		if (ret)
74 			return ret;
75 
76 		ret = regmap_write(iqs62x->regmap, IQS621_ALS_THRESH_DARK,
77 				   iqs621_als->thresh_dark);
78 	}
79 
80 	if (ret)
81 		return ret;
82 
83 	if (iqs621_als->light_en || iqs621_als->range_en)
84 		event_mask |= iqs62x->dev_desc->als_mask;
85 
86 	if (iqs621_als->prox_en)
87 		event_mask |= iqs62x->dev_desc->ir_mask;
88 
89 	return regmap_clear_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
90 				 event_mask);
91 }
92 
93 static int iqs621_als_notifier(struct notifier_block *notifier,
94 			       unsigned long event_flags, void *context)
95 {
96 	struct iqs62x_event_data *event_data = context;
97 	struct iqs621_als_private *iqs621_als;
98 	struct iio_dev *indio_dev;
99 	bool light_new, light_old;
100 	bool prox_new, prox_old;
101 	u8 range_new, range_old;
102 	s64 timestamp;
103 	int ret;
104 
105 	iqs621_als = container_of(notifier, struct iqs621_als_private,
106 				  notifier);
107 	indio_dev = iqs621_als->indio_dev;
108 	timestamp = iio_get_time_ns(indio_dev);
109 
110 	mutex_lock(&iqs621_als->lock);
111 
112 	if (event_flags & BIT(IQS62X_EVENT_SYS_RESET)) {
113 		ret = iqs621_als_init(iqs621_als);
114 		if (ret) {
115 			dev_err(indio_dev->dev.parent,
116 				"Failed to re-initialize device: %d\n", ret);
117 			ret = NOTIFY_BAD;
118 		} else {
119 			ret = NOTIFY_OK;
120 		}
121 
122 		goto err_mutex;
123 	}
124 
125 	if (!iqs621_als->light_en && !iqs621_als->range_en &&
126 	    !iqs621_als->prox_en) {
127 		ret = NOTIFY_DONE;
128 		goto err_mutex;
129 	}
130 
131 	/* IQS621 only */
132 	light_new = event_data->als_flags & IQS621_ALS_FLAGS_LIGHT;
133 	light_old = iqs621_als->als_flags & IQS621_ALS_FLAGS_LIGHT;
134 
135 	if (iqs621_als->light_en && light_new && !light_old)
136 		iio_push_event(indio_dev,
137 			       IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
138 						    IIO_EV_TYPE_THRESH,
139 						    IIO_EV_DIR_RISING),
140 			       timestamp);
141 	else if (iqs621_als->light_en && !light_new && light_old)
142 		iio_push_event(indio_dev,
143 			       IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
144 						    IIO_EV_TYPE_THRESH,
145 						    IIO_EV_DIR_FALLING),
146 			       timestamp);
147 
148 	/* IQS621 and IQS622 */
149 	range_new = event_data->als_flags & IQS621_ALS_FLAGS_RANGE;
150 	range_old = iqs621_als->als_flags & IQS621_ALS_FLAGS_RANGE;
151 
152 	if (iqs621_als->range_en && (range_new > range_old))
153 		iio_push_event(indio_dev,
154 			       IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
155 						    IIO_EV_TYPE_CHANGE,
156 						    IIO_EV_DIR_RISING),
157 			       timestamp);
158 	else if (iqs621_als->range_en && (range_new < range_old))
159 		iio_push_event(indio_dev,
160 			       IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
161 						    IIO_EV_TYPE_CHANGE,
162 						    IIO_EV_DIR_FALLING),
163 			       timestamp);
164 
165 	/* IQS622 only */
166 	prox_new = event_data->ir_flags & iqs621_als->ir_flags_mask;
167 	prox_old = iqs621_als->ir_flags & iqs621_als->ir_flags_mask;
168 
169 	if (iqs621_als->prox_en && prox_new && !prox_old)
170 		iio_push_event(indio_dev,
171 			       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
172 						    IIO_EV_TYPE_THRESH,
173 						    IIO_EV_DIR_RISING),
174 			       timestamp);
175 	else if (iqs621_als->prox_en && !prox_new && prox_old)
176 		iio_push_event(indio_dev,
177 			       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
178 						    IIO_EV_TYPE_THRESH,
179 						    IIO_EV_DIR_FALLING),
180 			       timestamp);
181 
182 	iqs621_als->als_flags = event_data->als_flags;
183 	iqs621_als->ir_flags = event_data->ir_flags;
184 	ret = NOTIFY_OK;
185 
186 err_mutex:
187 	mutex_unlock(&iqs621_als->lock);
188 
189 	return ret;
190 }
191 
192 static void iqs621_als_notifier_unregister(void *context)
193 {
194 	struct iqs621_als_private *iqs621_als = context;
195 	struct iio_dev *indio_dev = iqs621_als->indio_dev;
196 	int ret;
197 
198 	ret = blocking_notifier_chain_unregister(&iqs621_als->iqs62x->nh,
199 						 &iqs621_als->notifier);
200 	if (ret)
201 		dev_err(indio_dev->dev.parent,
202 			"Failed to unregister notifier: %d\n", ret);
203 }
204 
205 static int iqs621_als_read_raw(struct iio_dev *indio_dev,
206 			       struct iio_chan_spec const *chan,
207 			       int *val, int *val2, long mask)
208 {
209 	struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
210 	struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
211 	int ret;
212 	__le16 val_buf;
213 
214 	switch (chan->type) {
215 	case IIO_INTENSITY:
216 		ret = regmap_read(iqs62x->regmap, chan->address, val);
217 		if (ret)
218 			return ret;
219 
220 		*val &= IQS621_ALS_FLAGS_RANGE;
221 		return IIO_VAL_INT;
222 
223 	case IIO_PROXIMITY:
224 	case IIO_LIGHT:
225 		ret = regmap_raw_read(iqs62x->regmap, chan->address, &val_buf,
226 				      sizeof(val_buf));
227 		if (ret)
228 			return ret;
229 
230 		*val = le16_to_cpu(val_buf);
231 		return IIO_VAL_INT;
232 
233 	default:
234 		return -EINVAL;
235 	}
236 }
237 
238 static int iqs621_als_read_event_config(struct iio_dev *indio_dev,
239 					const struct iio_chan_spec *chan,
240 					enum iio_event_type type,
241 					enum iio_event_direction dir)
242 {
243 	struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
244 	int ret;
245 
246 	mutex_lock(&iqs621_als->lock);
247 
248 	switch (chan->type) {
249 	case IIO_LIGHT:
250 		ret = iqs621_als->light_en;
251 		break;
252 
253 	case IIO_INTENSITY:
254 		ret = iqs621_als->range_en;
255 		break;
256 
257 	case IIO_PROXIMITY:
258 		ret = iqs621_als->prox_en;
259 		break;
260 
261 	default:
262 		ret = -EINVAL;
263 	}
264 
265 	mutex_unlock(&iqs621_als->lock);
266 
267 	return ret;
268 }
269 
270 static int iqs621_als_write_event_config(struct iio_dev *indio_dev,
271 					 const struct iio_chan_spec *chan,
272 					 enum iio_event_type type,
273 					 enum iio_event_direction dir,
274 					 bool state)
275 {
276 	struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
277 	struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
278 	unsigned int val;
279 	int ret;
280 
281 	mutex_lock(&iqs621_als->lock);
282 
283 	ret = regmap_read(iqs62x->regmap, iqs62x->dev_desc->als_flags, &val);
284 	if (ret)
285 		goto err_mutex;
286 	iqs621_als->als_flags = val;
287 
288 	switch (chan->type) {
289 	case IIO_LIGHT:
290 		ret = regmap_update_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
291 					 iqs62x->dev_desc->als_mask,
292 					 iqs621_als->range_en || state ? 0 :
293 									 0xFF);
294 		if (!ret)
295 			iqs621_als->light_en = state;
296 		break;
297 
298 	case IIO_INTENSITY:
299 		ret = regmap_update_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
300 					 iqs62x->dev_desc->als_mask,
301 					 iqs621_als->light_en || state ? 0 :
302 									 0xFF);
303 		if (!ret)
304 			iqs621_als->range_en = state;
305 		break;
306 
307 	case IIO_PROXIMITY:
308 		ret = regmap_read(iqs62x->regmap, IQS622_IR_FLAGS, &val);
309 		if (ret)
310 			goto err_mutex;
311 		iqs621_als->ir_flags = val;
312 
313 		ret = regmap_update_bits(iqs62x->regmap, IQS620_GLBL_EVENT_MASK,
314 					 iqs62x->dev_desc->ir_mask,
315 					 state ? 0 : 0xFF);
316 		if (!ret)
317 			iqs621_als->prox_en = state;
318 		break;
319 
320 	default:
321 		ret = -EINVAL;
322 	}
323 
324 err_mutex:
325 	mutex_unlock(&iqs621_als->lock);
326 
327 	return ret;
328 }
329 
330 static int iqs621_als_read_event_value(struct iio_dev *indio_dev,
331 				       const struct iio_chan_spec *chan,
332 				       enum iio_event_type type,
333 				       enum iio_event_direction dir,
334 				       enum iio_event_info info,
335 				       int *val, int *val2)
336 {
337 	struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
338 	int ret = IIO_VAL_INT;
339 
340 	mutex_lock(&iqs621_als->lock);
341 
342 	switch (dir) {
343 	case IIO_EV_DIR_RISING:
344 		*val = iqs621_als->thresh_light * 16;
345 		break;
346 
347 	case IIO_EV_DIR_FALLING:
348 		*val = iqs621_als->thresh_dark * 4;
349 		break;
350 
351 	case IIO_EV_DIR_EITHER:
352 		if (iqs621_als->ir_flags_mask == IQS622_IR_FLAGS_TOUCH)
353 			*val = iqs621_als->thresh_prox * 4;
354 		else
355 			*val = iqs621_als->thresh_prox;
356 		break;
357 
358 	default:
359 		ret = -EINVAL;
360 	}
361 
362 	mutex_unlock(&iqs621_als->lock);
363 
364 	return ret;
365 }
366 
367 static int iqs621_als_write_event_value(struct iio_dev *indio_dev,
368 					const struct iio_chan_spec *chan,
369 					enum iio_event_type type,
370 					enum iio_event_direction dir,
371 					enum iio_event_info info,
372 					int val, int val2)
373 {
374 	struct iqs621_als_private *iqs621_als = iio_priv(indio_dev);
375 	struct iqs62x_core *iqs62x = iqs621_als->iqs62x;
376 	unsigned int thresh_reg, thresh_val;
377 	u8 ir_flags_mask, *thresh_cache;
378 	int ret = -EINVAL;
379 
380 	mutex_lock(&iqs621_als->lock);
381 
382 	switch (dir) {
383 	case IIO_EV_DIR_RISING:
384 		thresh_reg = IQS621_ALS_THRESH_LIGHT;
385 		thresh_val = val / 16;
386 
387 		thresh_cache = &iqs621_als->thresh_light;
388 		ir_flags_mask = 0;
389 		break;
390 
391 	case IIO_EV_DIR_FALLING:
392 		thresh_reg = IQS621_ALS_THRESH_DARK;
393 		thresh_val = val / 4;
394 
395 		thresh_cache = &iqs621_als->thresh_dark;
396 		ir_flags_mask = 0;
397 		break;
398 
399 	case IIO_EV_DIR_EITHER:
400 		/*
401 		 * The IQS622 supports two detection thresholds, both measured
402 		 * in the same arbitrary units reported by read_raw: proximity
403 		 * (0 through 255 in steps of 1), and touch (0 through 1020 in
404 		 * steps of 4).
405 		 *
406 		 * Based on the single detection threshold chosen by the user,
407 		 * select the hardware threshold that gives the best trade-off
408 		 * between range and resolution.
409 		 *
410 		 * By default, the close-range (but coarse) touch threshold is
411 		 * chosen during probe.
412 		 */
413 		switch (val) {
414 		case 0 ... 255:
415 			thresh_reg = IQS622_IR_THRESH_PROX;
416 			thresh_val = val;
417 
418 			ir_flags_mask = IQS622_IR_FLAGS_PROX;
419 			break;
420 
421 		case 256 ... 1020:
422 			thresh_reg = IQS622_IR_THRESH_TOUCH;
423 			thresh_val = val / 4;
424 
425 			ir_flags_mask = IQS622_IR_FLAGS_TOUCH;
426 			break;
427 
428 		default:
429 			goto err_mutex;
430 		}
431 
432 		thresh_cache = &iqs621_als->thresh_prox;
433 		break;
434 
435 	default:
436 		goto err_mutex;
437 	}
438 
439 	if (thresh_val > 0xFF)
440 		goto err_mutex;
441 
442 	ret = regmap_write(iqs62x->regmap, thresh_reg, thresh_val);
443 	if (ret)
444 		goto err_mutex;
445 
446 	*thresh_cache = thresh_val;
447 	iqs621_als->ir_flags_mask = ir_flags_mask;
448 
449 err_mutex:
450 	mutex_unlock(&iqs621_als->lock);
451 
452 	return ret;
453 }
454 
455 static const struct iio_info iqs621_als_info = {
456 	.read_raw = &iqs621_als_read_raw,
457 	.read_event_config = iqs621_als_read_event_config,
458 	.write_event_config = iqs621_als_write_event_config,
459 	.read_event_value = iqs621_als_read_event_value,
460 	.write_event_value = iqs621_als_write_event_value,
461 };
462 
463 static const struct iio_event_spec iqs621_als_range_events[] = {
464 	{
465 		.type = IIO_EV_TYPE_CHANGE,
466 		.dir = IIO_EV_DIR_EITHER,
467 		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
468 	},
469 };
470 
471 static const struct iio_event_spec iqs621_als_light_events[] = {
472 	{
473 		.type = IIO_EV_TYPE_THRESH,
474 		.dir = IIO_EV_DIR_EITHER,
475 		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
476 	},
477 	{
478 		.type = IIO_EV_TYPE_THRESH,
479 		.dir = IIO_EV_DIR_RISING,
480 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
481 	},
482 	{
483 		.type = IIO_EV_TYPE_THRESH,
484 		.dir = IIO_EV_DIR_FALLING,
485 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
486 	},
487 };
488 
489 static const struct iio_chan_spec iqs621_als_channels[] = {
490 	{
491 		.type = IIO_INTENSITY,
492 		.address = IQS621_ALS_FLAGS,
493 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
494 		.event_spec = iqs621_als_range_events,
495 		.num_event_specs = ARRAY_SIZE(iqs621_als_range_events),
496 	},
497 	{
498 		.type = IIO_LIGHT,
499 		.address = IQS621_ALS_UI_OUT,
500 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
501 		.event_spec = iqs621_als_light_events,
502 		.num_event_specs = ARRAY_SIZE(iqs621_als_light_events),
503 	},
504 };
505 
506 static const struct iio_event_spec iqs622_als_prox_events[] = {
507 	{
508 		.type = IIO_EV_TYPE_THRESH,
509 		.dir = IIO_EV_DIR_EITHER,
510 		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
511 				 BIT(IIO_EV_INFO_VALUE),
512 	},
513 };
514 
515 static const struct iio_chan_spec iqs622_als_channels[] = {
516 	{
517 		.type = IIO_INTENSITY,
518 		.channel2 = IIO_MOD_LIGHT_BOTH,
519 		.address = IQS622_ALS_FLAGS,
520 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
521 		.event_spec = iqs621_als_range_events,
522 		.num_event_specs = ARRAY_SIZE(iqs621_als_range_events),
523 		.modified = true,
524 	},
525 	{
526 		.type = IIO_INTENSITY,
527 		.channel2 = IIO_MOD_LIGHT_IR,
528 		.address = IQS622_IR_RANGE,
529 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
530 		.modified = true,
531 	},
532 	{
533 		.type = IIO_PROXIMITY,
534 		.address = IQS622_IR_UI_OUT,
535 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
536 		.event_spec = iqs622_als_prox_events,
537 		.num_event_specs = ARRAY_SIZE(iqs622_als_prox_events),
538 	},
539 };
540 
541 static int iqs621_als_probe(struct platform_device *pdev)
542 {
543 	struct iqs62x_core *iqs62x = dev_get_drvdata(pdev->dev.parent);
544 	struct iqs621_als_private *iqs621_als;
545 	struct iio_dev *indio_dev;
546 	unsigned int val;
547 	int ret;
548 
549 	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*iqs621_als));
550 	if (!indio_dev)
551 		return -ENOMEM;
552 
553 	iqs621_als = iio_priv(indio_dev);
554 	iqs621_als->iqs62x = iqs62x;
555 	iqs621_als->indio_dev = indio_dev;
556 
557 	if (iqs62x->dev_desc->prod_num == IQS622_PROD_NUM) {
558 		ret = regmap_read(iqs62x->regmap, IQS622_IR_THRESH_TOUCH,
559 				  &val);
560 		if (ret)
561 			return ret;
562 		iqs621_als->thresh_prox = val;
563 		iqs621_als->ir_flags_mask = IQS622_IR_FLAGS_TOUCH;
564 
565 		indio_dev->channels = iqs622_als_channels;
566 		indio_dev->num_channels = ARRAY_SIZE(iqs622_als_channels);
567 	} else {
568 		ret = regmap_read(iqs62x->regmap, IQS621_ALS_THRESH_LIGHT,
569 				  &val);
570 		if (ret)
571 			return ret;
572 		iqs621_als->thresh_light = val;
573 
574 		ret = regmap_read(iqs62x->regmap, IQS621_ALS_THRESH_DARK,
575 				  &val);
576 		if (ret)
577 			return ret;
578 		iqs621_als->thresh_dark = val;
579 
580 		indio_dev->channels = iqs621_als_channels;
581 		indio_dev->num_channels = ARRAY_SIZE(iqs621_als_channels);
582 	}
583 
584 	indio_dev->modes = INDIO_DIRECT_MODE;
585 	indio_dev->name = iqs62x->dev_desc->dev_name;
586 	indio_dev->info = &iqs621_als_info;
587 
588 	mutex_init(&iqs621_als->lock);
589 
590 	iqs621_als->notifier.notifier_call = iqs621_als_notifier;
591 	ret = blocking_notifier_chain_register(&iqs621_als->iqs62x->nh,
592 					       &iqs621_als->notifier);
593 	if (ret) {
594 		dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret);
595 		return ret;
596 	}
597 
598 	ret = devm_add_action_or_reset(&pdev->dev,
599 				       iqs621_als_notifier_unregister,
600 				       iqs621_als);
601 	if (ret)
602 		return ret;
603 
604 	return devm_iio_device_register(&pdev->dev, indio_dev);
605 }
606 
607 static struct platform_driver iqs621_als_platform_driver = {
608 	.driver = {
609 		.name = "iqs621-als",
610 	},
611 	.probe = iqs621_als_probe,
612 };
613 module_platform_driver(iqs621_als_platform_driver);
614 
615 MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
616 MODULE_DESCRIPTION("Azoteq IQS621/622 Ambient Light Sensors");
617 MODULE_LICENSE("GPL");
618 MODULE_ALIAS("platform:iqs621-als");
619