xref: /linux/drivers/iio/light/tcs3472.c (revision 666ed8bfd1de3b091cf32ca03b651757dd86cfff)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * tcs3472.c - Support for TAOS TCS3472 color light-to-digital converter
4  *
5  * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>
6  *
7  * Color light sensor with 16-bit channels for red, green, blue, clear);
8  * 7-bit I2C slave address 0x39 (TCS34721, TCS34723) or 0x29 (TCS34725,
9  * TCS34727)
10  *
11  * Datasheet: http://ams.com/eng/content/download/319364/1117183/file/TCS3472_Datasheet_EN_v2.pdf
12  *
13  * TODO: wait time
14  */
15 
16 #include <linux/module.h>
17 #include <linux/i2c.h>
18 #include <linux/delay.h>
19 #include <linux/pm.h>
20 
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/events.h>
24 #include <linux/iio/trigger_consumer.h>
25 #include <linux/iio/buffer.h>
26 #include <linux/iio/triggered_buffer.h>
27 
28 #define TCS3472_DRV_NAME "tcs3472"
29 
30 #define TCS3472_COMMAND BIT(7)
31 #define TCS3472_AUTO_INCR BIT(5)
32 #define TCS3472_SPECIAL_FUNC (BIT(5) | BIT(6))
33 
34 #define TCS3472_INTR_CLEAR (TCS3472_COMMAND | TCS3472_SPECIAL_FUNC | 0x06)
35 
36 #define TCS3472_ENABLE (TCS3472_COMMAND | 0x00)
37 #define TCS3472_ATIME (TCS3472_COMMAND | 0x01)
38 #define TCS3472_WTIME (TCS3472_COMMAND | 0x03)
39 #define TCS3472_AILT (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x04)
40 #define TCS3472_AIHT (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x06)
41 #define TCS3472_PERS (TCS3472_COMMAND | 0x0c)
42 #define TCS3472_CONFIG (TCS3472_COMMAND | 0x0d)
43 #define TCS3472_CONTROL (TCS3472_COMMAND | 0x0f)
44 #define TCS3472_ID (TCS3472_COMMAND | 0x12)
45 #define TCS3472_STATUS (TCS3472_COMMAND | 0x13)
46 #define TCS3472_CDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x14)
47 #define TCS3472_RDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x16)
48 #define TCS3472_GDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x18)
49 #define TCS3472_BDATA (TCS3472_COMMAND | TCS3472_AUTO_INCR | 0x1a)
50 
51 #define TCS3472_STATUS_AINT BIT(4)
52 #define TCS3472_STATUS_AVALID BIT(0)
53 #define TCS3472_ENABLE_AIEN BIT(4)
54 #define TCS3472_ENABLE_AEN BIT(1)
55 #define TCS3472_ENABLE_PON BIT(0)
56 #define TCS3472_CONTROL_AGAIN_MASK (BIT(0) | BIT(1))
57 
58 struct tcs3472_data {
59 	struct i2c_client *client;
60 	struct mutex lock;
61 	u16 low_thresh;
62 	u16 high_thresh;
63 	u8 enable;
64 	u8 control;
65 	u8 atime;
66 	u8 apers;
67 	u16 buffer[8]; /* 4 16-bit channels + 64-bit timestamp */
68 };
69 
70 static const struct iio_event_spec tcs3472_events[] = {
71 	{
72 		.type = IIO_EV_TYPE_THRESH,
73 		.dir = IIO_EV_DIR_RISING,
74 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
75 	}, {
76 		.type = IIO_EV_TYPE_THRESH,
77 		.dir = IIO_EV_DIR_FALLING,
78 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
79 	}, {
80 		.type = IIO_EV_TYPE_THRESH,
81 		.dir = IIO_EV_DIR_EITHER,
82 		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
83 				 BIT(IIO_EV_INFO_PERIOD),
84 	},
85 };
86 
87 #define TCS3472_CHANNEL(_color, _si, _addr) { \
88 	.type = IIO_INTENSITY, \
89 	.modified = 1, \
90 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
91 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBSCALE) | \
92 		BIT(IIO_CHAN_INFO_INT_TIME), \
93 	.channel2 = IIO_MOD_LIGHT_##_color, \
94 	.address = _addr, \
95 	.scan_index = _si, \
96 	.scan_type = { \
97 		.sign = 'u', \
98 		.realbits = 16, \
99 		.storagebits = 16, \
100 		.endianness = IIO_CPU, \
101 	}, \
102 	.event_spec = _si ? NULL : tcs3472_events, \
103 	.num_event_specs = _si ? 0 : ARRAY_SIZE(tcs3472_events), \
104 }
105 
106 static const int tcs3472_agains[] = { 1, 4, 16, 60 };
107 
108 static const struct iio_chan_spec tcs3472_channels[] = {
109 	TCS3472_CHANNEL(CLEAR, 0, TCS3472_CDATA),
110 	TCS3472_CHANNEL(RED, 1, TCS3472_RDATA),
111 	TCS3472_CHANNEL(GREEN, 2, TCS3472_GDATA),
112 	TCS3472_CHANNEL(BLUE, 3, TCS3472_BDATA),
113 	IIO_CHAN_SOFT_TIMESTAMP(4),
114 };
115 
116 static int tcs3472_req_data(struct tcs3472_data *data)
117 {
118 	int tries = 50;
119 	int ret;
120 
121 	while (tries--) {
122 		ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);
123 		if (ret < 0)
124 			return ret;
125 		if (ret & TCS3472_STATUS_AVALID)
126 			break;
127 		msleep(20);
128 	}
129 
130 	if (tries < 0) {
131 		dev_err(&data->client->dev, "data not ready\n");
132 		return -EIO;
133 	}
134 
135 	return 0;
136 }
137 
138 static int tcs3472_read_raw(struct iio_dev *indio_dev,
139 			   struct iio_chan_spec const *chan,
140 			   int *val, int *val2, long mask)
141 {
142 	struct tcs3472_data *data = iio_priv(indio_dev);
143 	int ret;
144 
145 	switch (mask) {
146 	case IIO_CHAN_INFO_RAW:
147 		ret = iio_device_claim_direct_mode(indio_dev);
148 		if (ret)
149 			return ret;
150 		ret = tcs3472_req_data(data);
151 		if (ret < 0) {
152 			iio_device_release_direct_mode(indio_dev);
153 			return ret;
154 		}
155 		ret = i2c_smbus_read_word_data(data->client, chan->address);
156 		iio_device_release_direct_mode(indio_dev);
157 		if (ret < 0)
158 			return ret;
159 		*val = ret;
160 		return IIO_VAL_INT;
161 	case IIO_CHAN_INFO_CALIBSCALE:
162 		*val = tcs3472_agains[data->control &
163 			TCS3472_CONTROL_AGAIN_MASK];
164 		return IIO_VAL_INT;
165 	case IIO_CHAN_INFO_INT_TIME:
166 		*val = 0;
167 		*val2 = (256 - data->atime) * 2400;
168 		return IIO_VAL_INT_PLUS_MICRO;
169 	}
170 	return -EINVAL;
171 }
172 
173 static int tcs3472_write_raw(struct iio_dev *indio_dev,
174 			       struct iio_chan_spec const *chan,
175 			       int val, int val2, long mask)
176 {
177 	struct tcs3472_data *data = iio_priv(indio_dev);
178 	int i;
179 
180 	switch (mask) {
181 	case IIO_CHAN_INFO_CALIBSCALE:
182 		if (val2 != 0)
183 			return -EINVAL;
184 		for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) {
185 			if (val == tcs3472_agains[i]) {
186 				data->control &= ~TCS3472_CONTROL_AGAIN_MASK;
187 				data->control |= i;
188 				return i2c_smbus_write_byte_data(
189 					data->client, TCS3472_CONTROL,
190 					data->control);
191 			}
192 		}
193 		return -EINVAL;
194 	case IIO_CHAN_INFO_INT_TIME:
195 		if (val != 0)
196 			return -EINVAL;
197 		for (i = 0; i < 256; i++) {
198 			if (val2 == (256 - i) * 2400) {
199 				data->atime = i;
200 				return i2c_smbus_write_byte_data(
201 					data->client, TCS3472_ATIME,
202 					data->atime);
203 			}
204 
205 		}
206 		return -EINVAL;
207 	}
208 	return -EINVAL;
209 }
210 
211 /*
212  * Translation from APERS field value to the number of consecutive out-of-range
213  * clear channel values before an interrupt is generated
214  */
215 static const int tcs3472_intr_pers[] = {
216 	0, 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60
217 };
218 
219 static int tcs3472_read_event(struct iio_dev *indio_dev,
220 	const struct iio_chan_spec *chan, enum iio_event_type type,
221 	enum iio_event_direction dir, enum iio_event_info info, int *val,
222 	int *val2)
223 {
224 	struct tcs3472_data *data = iio_priv(indio_dev);
225 	int ret;
226 	unsigned int period;
227 
228 	mutex_lock(&data->lock);
229 
230 	switch (info) {
231 	case IIO_EV_INFO_VALUE:
232 		*val = (dir == IIO_EV_DIR_RISING) ?
233 			data->high_thresh : data->low_thresh;
234 		ret = IIO_VAL_INT;
235 		break;
236 	case IIO_EV_INFO_PERIOD:
237 		period = (256 - data->atime) * 2400 *
238 			tcs3472_intr_pers[data->apers];
239 		*val = period / USEC_PER_SEC;
240 		*val2 = period % USEC_PER_SEC;
241 		ret = IIO_VAL_INT_PLUS_MICRO;
242 		break;
243 	default:
244 		ret = -EINVAL;
245 		break;
246 	}
247 
248 	mutex_unlock(&data->lock);
249 
250 	return ret;
251 }
252 
253 static int tcs3472_write_event(struct iio_dev *indio_dev,
254 	const struct iio_chan_spec *chan, enum iio_event_type type,
255 	enum iio_event_direction dir, enum iio_event_info info, int val,
256 	int val2)
257 {
258 	struct tcs3472_data *data = iio_priv(indio_dev);
259 	int ret;
260 	u8 command;
261 	int period;
262 	int i;
263 
264 	mutex_lock(&data->lock);
265 	switch (info) {
266 	case IIO_EV_INFO_VALUE:
267 		switch (dir) {
268 		case IIO_EV_DIR_RISING:
269 			command = TCS3472_AIHT;
270 			break;
271 		case IIO_EV_DIR_FALLING:
272 			command = TCS3472_AILT;
273 			break;
274 		default:
275 			ret = -EINVAL;
276 			goto error;
277 		}
278 		ret = i2c_smbus_write_word_data(data->client, command, val);
279 		if (ret)
280 			goto error;
281 
282 		if (dir == IIO_EV_DIR_RISING)
283 			data->high_thresh = val;
284 		else
285 			data->low_thresh = val;
286 		break;
287 	case IIO_EV_INFO_PERIOD:
288 		period = val * USEC_PER_SEC + val2;
289 		for (i = 1; i < ARRAY_SIZE(tcs3472_intr_pers) - 1; i++) {
290 			if (period <= (256 - data->atime) * 2400 *
291 					tcs3472_intr_pers[i])
292 				break;
293 		}
294 		ret = i2c_smbus_write_byte_data(data->client, TCS3472_PERS, i);
295 		if (ret)
296 			goto error;
297 
298 		data->apers = i;
299 		break;
300 	default:
301 		ret = -EINVAL;
302 		break;
303 	}
304 error:
305 	mutex_unlock(&data->lock);
306 
307 	return ret;
308 }
309 
310 static int tcs3472_read_event_config(struct iio_dev *indio_dev,
311 	const struct iio_chan_spec *chan, enum iio_event_type type,
312 	enum iio_event_direction dir)
313 {
314 	struct tcs3472_data *data = iio_priv(indio_dev);
315 	int ret;
316 
317 	mutex_lock(&data->lock);
318 	ret = !!(data->enable & TCS3472_ENABLE_AIEN);
319 	mutex_unlock(&data->lock);
320 
321 	return ret;
322 }
323 
324 static int tcs3472_write_event_config(struct iio_dev *indio_dev,
325 	const struct iio_chan_spec *chan, enum iio_event_type type,
326 	enum iio_event_direction dir, int state)
327 {
328 	struct tcs3472_data *data = iio_priv(indio_dev);
329 	int ret = 0;
330 	u8 enable_old;
331 
332 	mutex_lock(&data->lock);
333 
334 	enable_old = data->enable;
335 
336 	if (state)
337 		data->enable |= TCS3472_ENABLE_AIEN;
338 	else
339 		data->enable &= ~TCS3472_ENABLE_AIEN;
340 
341 	if (enable_old != data->enable) {
342 		ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
343 						data->enable);
344 		if (ret)
345 			data->enable = enable_old;
346 	}
347 	mutex_unlock(&data->lock);
348 
349 	return ret;
350 }
351 
352 static irqreturn_t tcs3472_event_handler(int irq, void *priv)
353 {
354 	struct iio_dev *indio_dev = priv;
355 	struct tcs3472_data *data = iio_priv(indio_dev);
356 	int ret;
357 
358 	ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);
359 	if (ret >= 0 && (ret & TCS3472_STATUS_AINT)) {
360 		iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
361 						IIO_EV_TYPE_THRESH,
362 						IIO_EV_DIR_EITHER),
363 				iio_get_time_ns(indio_dev));
364 
365 		i2c_smbus_read_byte_data(data->client, TCS3472_INTR_CLEAR);
366 	}
367 
368 	return IRQ_HANDLED;
369 }
370 
371 static irqreturn_t tcs3472_trigger_handler(int irq, void *p)
372 {
373 	struct iio_poll_func *pf = p;
374 	struct iio_dev *indio_dev = pf->indio_dev;
375 	struct tcs3472_data *data = iio_priv(indio_dev);
376 	int i, j = 0;
377 
378 	int ret = tcs3472_req_data(data);
379 	if (ret < 0)
380 		goto done;
381 
382 	for_each_set_bit(i, indio_dev->active_scan_mask,
383 		indio_dev->masklength) {
384 		ret = i2c_smbus_read_word_data(data->client,
385 			TCS3472_CDATA + 2*i);
386 		if (ret < 0)
387 			goto done;
388 
389 		data->buffer[j++] = ret;
390 	}
391 
392 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
393 		iio_get_time_ns(indio_dev));
394 
395 done:
396 	iio_trigger_notify_done(indio_dev->trig);
397 
398 	return IRQ_HANDLED;
399 }
400 
401 static ssize_t tcs3472_show_int_time_available(struct device *dev,
402 					struct device_attribute *attr,
403 					char *buf)
404 {
405 	size_t len = 0;
406 	int i;
407 
408 	for (i = 1; i <= 256; i++)
409 		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
410 			2400 * i);
411 
412 	/* replace trailing space by newline */
413 	buf[len - 1] = '\n';
414 
415 	return len;
416 }
417 
418 static IIO_CONST_ATTR(calibscale_available, "1 4 16 60");
419 static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available);
420 
421 static struct attribute *tcs3472_attributes[] = {
422 	&iio_const_attr_calibscale_available.dev_attr.attr,
423 	&iio_dev_attr_integration_time_available.dev_attr.attr,
424 	NULL
425 };
426 
427 static const struct attribute_group tcs3472_attribute_group = {
428 	.attrs = tcs3472_attributes,
429 };
430 
431 static const struct iio_info tcs3472_info = {
432 	.read_raw = tcs3472_read_raw,
433 	.write_raw = tcs3472_write_raw,
434 	.read_event_value = tcs3472_read_event,
435 	.write_event_value = tcs3472_write_event,
436 	.read_event_config = tcs3472_read_event_config,
437 	.write_event_config = tcs3472_write_event_config,
438 	.attrs = &tcs3472_attribute_group,
439 };
440 
441 static int tcs3472_probe(struct i2c_client *client,
442 			   const struct i2c_device_id *id)
443 {
444 	struct tcs3472_data *data;
445 	struct iio_dev *indio_dev;
446 	int ret;
447 
448 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
449 	if (indio_dev == NULL)
450 		return -ENOMEM;
451 
452 	data = iio_priv(indio_dev);
453 	i2c_set_clientdata(client, indio_dev);
454 	data->client = client;
455 	mutex_init(&data->lock);
456 
457 	indio_dev->dev.parent = &client->dev;
458 	indio_dev->info = &tcs3472_info;
459 	indio_dev->name = TCS3472_DRV_NAME;
460 	indio_dev->channels = tcs3472_channels;
461 	indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels);
462 	indio_dev->modes = INDIO_DIRECT_MODE;
463 
464 	ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID);
465 	if (ret < 0)
466 		return ret;
467 
468 	if (ret == 0x44)
469 		dev_info(&client->dev, "TCS34721/34725 found\n");
470 	else if (ret == 0x4d)
471 		dev_info(&client->dev, "TCS34723/34727 found\n");
472 	else
473 		return -ENODEV;
474 
475 	ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL);
476 	if (ret < 0)
477 		return ret;
478 	data->control = ret;
479 
480 	ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME);
481 	if (ret < 0)
482 		return ret;
483 	data->atime = ret;
484 
485 	ret = i2c_smbus_read_word_data(data->client, TCS3472_AILT);
486 	if (ret < 0)
487 		return ret;
488 	data->low_thresh = ret;
489 
490 	ret = i2c_smbus_read_word_data(data->client, TCS3472_AIHT);
491 	if (ret < 0)
492 		return ret;
493 	data->high_thresh = ret;
494 
495 	data->apers = 1;
496 	ret = i2c_smbus_write_byte_data(data->client, TCS3472_PERS,
497 					data->apers);
498 	if (ret < 0)
499 		return ret;
500 
501 	ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE);
502 	if (ret < 0)
503 		return ret;
504 
505 	/* enable device */
506 	data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN;
507 	data->enable &= ~TCS3472_ENABLE_AIEN;
508 	ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
509 		data->enable);
510 	if (ret < 0)
511 		return ret;
512 
513 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
514 		tcs3472_trigger_handler, NULL);
515 	if (ret < 0)
516 		return ret;
517 
518 	if (client->irq) {
519 		ret = request_threaded_irq(client->irq, NULL,
520 					   tcs3472_event_handler,
521 					   IRQF_TRIGGER_FALLING | IRQF_SHARED |
522 					   IRQF_ONESHOT,
523 					   client->name, indio_dev);
524 		if (ret)
525 			goto buffer_cleanup;
526 	}
527 
528 	ret = iio_device_register(indio_dev);
529 	if (ret < 0)
530 		goto free_irq;
531 
532 	return 0;
533 
534 free_irq:
535 	free_irq(client->irq, indio_dev);
536 buffer_cleanup:
537 	iio_triggered_buffer_cleanup(indio_dev);
538 	return ret;
539 }
540 
541 static int tcs3472_powerdown(struct tcs3472_data *data)
542 {
543 	int ret;
544 	u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;
545 
546 	mutex_lock(&data->lock);
547 
548 	ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
549 		data->enable & ~enable_mask);
550 	if (!ret)
551 		data->enable &= ~enable_mask;
552 
553 	mutex_unlock(&data->lock);
554 
555 	return ret;
556 }
557 
558 static int tcs3472_remove(struct i2c_client *client)
559 {
560 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
561 
562 	iio_device_unregister(indio_dev);
563 	free_irq(client->irq, indio_dev);
564 	iio_triggered_buffer_cleanup(indio_dev);
565 	tcs3472_powerdown(iio_priv(indio_dev));
566 
567 	return 0;
568 }
569 
570 #ifdef CONFIG_PM_SLEEP
571 static int tcs3472_suspend(struct device *dev)
572 {
573 	struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
574 		to_i2c_client(dev)));
575 	return tcs3472_powerdown(data);
576 }
577 
578 static int tcs3472_resume(struct device *dev)
579 {
580 	struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
581 		to_i2c_client(dev)));
582 	int ret;
583 	u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;
584 
585 	mutex_lock(&data->lock);
586 
587 	ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
588 		data->enable | enable_mask);
589 	if (!ret)
590 		data->enable |= enable_mask;
591 
592 	mutex_unlock(&data->lock);
593 
594 	return ret;
595 }
596 #endif
597 
598 static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume);
599 
600 static const struct i2c_device_id tcs3472_id[] = {
601 	{ "tcs3472", 0 },
602 	{ }
603 };
604 MODULE_DEVICE_TABLE(i2c, tcs3472_id);
605 
606 static struct i2c_driver tcs3472_driver = {
607 	.driver = {
608 		.name	= TCS3472_DRV_NAME,
609 		.pm	= &tcs3472_pm_ops,
610 	},
611 	.probe		= tcs3472_probe,
612 	.remove		= tcs3472_remove,
613 	.id_table	= tcs3472_id,
614 };
615 module_i2c_driver(tcs3472_driver);
616 
617 MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
618 MODULE_DESCRIPTION("TCS3472 color light sensors driver");
619 MODULE_LICENSE("GPL");
620