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  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
 58struct 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	/* Ensure timestamp is naturally aligned */
 68	struct {
 69		u16 chans[4];
 70		s64 timestamp __aligned(8);
 71	} scan;
 72};
 73
 74static const struct iio_event_spec tcs3472_events[] = {
 75	{
 76		.type = IIO_EV_TYPE_THRESH,
 77		.dir = IIO_EV_DIR_RISING,
 78		.mask_separate = BIT(IIO_EV_INFO_VALUE),
 79	}, {
 80		.type = IIO_EV_TYPE_THRESH,
 81		.dir = IIO_EV_DIR_FALLING,
 82		.mask_separate = BIT(IIO_EV_INFO_VALUE),
 83	}, {
 84		.type = IIO_EV_TYPE_THRESH,
 85		.dir = IIO_EV_DIR_EITHER,
 86		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
 87				 BIT(IIO_EV_INFO_PERIOD),
 88	},
 89};
 90
 91#define TCS3472_CHANNEL(_color, _si, _addr) { \
 92	.type = IIO_INTENSITY, \
 93	.modified = 1, \
 94	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 95	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_CALIBSCALE) | \
 96		BIT(IIO_CHAN_INFO_INT_TIME), \
 97	.channel2 = IIO_MOD_LIGHT_##_color, \
 98	.address = _addr, \
 99	.scan_index = _si, \
100	.scan_type = { \
101		.sign = 'u', \
102		.realbits = 16, \
103		.storagebits = 16, \
104		.endianness = IIO_CPU, \
105	}, \
106	.event_spec = _si ? NULL : tcs3472_events, \
107	.num_event_specs = _si ? 0 : ARRAY_SIZE(tcs3472_events), \
108}
109
110static const int tcs3472_agains[] = { 1, 4, 16, 60 };
111
112static const struct iio_chan_spec tcs3472_channels[] = {
113	TCS3472_CHANNEL(CLEAR, 0, TCS3472_CDATA),
114	TCS3472_CHANNEL(RED, 1, TCS3472_RDATA),
115	TCS3472_CHANNEL(GREEN, 2, TCS3472_GDATA),
116	TCS3472_CHANNEL(BLUE, 3, TCS3472_BDATA),
117	IIO_CHAN_SOFT_TIMESTAMP(4),
118};
119
120static int tcs3472_req_data(struct tcs3472_data *data)
121{
122	int tries = 50;
123	int ret;
124
125	while (tries--) {
126		ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);
127		if (ret < 0)
128			return ret;
129		if (ret & TCS3472_STATUS_AVALID)
130			break;
131		msleep(20);
132	}
133
134	if (tries < 0) {
135		dev_err(&data->client->dev, "data not ready\n");
136		return -EIO;
137	}
138
139	return 0;
140}
141
142static int tcs3472_read_raw(struct iio_dev *indio_dev,
143			   struct iio_chan_spec const *chan,
144			   int *val, int *val2, long mask)
145{
146	struct tcs3472_data *data = iio_priv(indio_dev);
147	int ret;
148
149	switch (mask) {
150	case IIO_CHAN_INFO_RAW:
151		ret = iio_device_claim_direct_mode(indio_dev);
152		if (ret)
153			return ret;
154		ret = tcs3472_req_data(data);
155		if (ret < 0) {
156			iio_device_release_direct_mode(indio_dev);
157			return ret;
158		}
159		ret = i2c_smbus_read_word_data(data->client, chan->address);
160		iio_device_release_direct_mode(indio_dev);
161		if (ret < 0)
162			return ret;
163		*val = ret;
164		return IIO_VAL_INT;
165	case IIO_CHAN_INFO_CALIBSCALE:
166		*val = tcs3472_agains[data->control &
167			TCS3472_CONTROL_AGAIN_MASK];
168		return IIO_VAL_INT;
169	case IIO_CHAN_INFO_INT_TIME:
170		*val = 0;
171		*val2 = (256 - data->atime) * 2400;
172		return IIO_VAL_INT_PLUS_MICRO;
173	}
174	return -EINVAL;
175}
176
177static int tcs3472_write_raw(struct iio_dev *indio_dev,
178			       struct iio_chan_spec const *chan,
179			       int val, int val2, long mask)
180{
181	struct tcs3472_data *data = iio_priv(indio_dev);
182	int i;
183
184	switch (mask) {
185	case IIO_CHAN_INFO_CALIBSCALE:
186		if (val2 != 0)
187			return -EINVAL;
188		for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) {
189			if (val == tcs3472_agains[i]) {
190				data->control &= ~TCS3472_CONTROL_AGAIN_MASK;
191				data->control |= i;
192				return i2c_smbus_write_byte_data(
193					data->client, TCS3472_CONTROL,
194					data->control);
195			}
196		}
197		return -EINVAL;
198	case IIO_CHAN_INFO_INT_TIME:
199		if (val != 0)
200			return -EINVAL;
201		for (i = 0; i < 256; i++) {
202			if (val2 == (256 - i) * 2400) {
203				data->atime = i;
204				return i2c_smbus_write_byte_data(
205					data->client, TCS3472_ATIME,
206					data->atime);
207			}
208
209		}
210		return -EINVAL;
211	}
212	return -EINVAL;
213}
214
215/*
216 * Translation from APERS field value to the number of consecutive out-of-range
217 * clear channel values before an interrupt is generated
218 */
219static const int tcs3472_intr_pers[] = {
220	0, 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60
221};
222
223static int tcs3472_read_event(struct iio_dev *indio_dev,
224	const struct iio_chan_spec *chan, enum iio_event_type type,
225	enum iio_event_direction dir, enum iio_event_info info, int *val,
226	int *val2)
227{
228	struct tcs3472_data *data = iio_priv(indio_dev);
229	int ret;
230	unsigned int period;
231
232	mutex_lock(&data->lock);
233
234	switch (info) {
235	case IIO_EV_INFO_VALUE:
236		*val = (dir == IIO_EV_DIR_RISING) ?
237			data->high_thresh : data->low_thresh;
238		ret = IIO_VAL_INT;
239		break;
240	case IIO_EV_INFO_PERIOD:
241		period = (256 - data->atime) * 2400 *
242			tcs3472_intr_pers[data->apers];
243		*val = period / USEC_PER_SEC;
244		*val2 = period % USEC_PER_SEC;
245		ret = IIO_VAL_INT_PLUS_MICRO;
246		break;
247	default:
248		ret = -EINVAL;
249		break;
250	}
251
252	mutex_unlock(&data->lock);
253
254	return ret;
255}
256
257static int tcs3472_write_event(struct iio_dev *indio_dev,
258	const struct iio_chan_spec *chan, enum iio_event_type type,
259	enum iio_event_direction dir, enum iio_event_info info, int val,
260	int val2)
261{
262	struct tcs3472_data *data = iio_priv(indio_dev);
263	int ret;
264	u8 command;
265	int period;
266	int i;
267
268	mutex_lock(&data->lock);
269	switch (info) {
270	case IIO_EV_INFO_VALUE:
271		switch (dir) {
272		case IIO_EV_DIR_RISING:
273			command = TCS3472_AIHT;
274			break;
275		case IIO_EV_DIR_FALLING:
276			command = TCS3472_AILT;
277			break;
278		default:
279			ret = -EINVAL;
280			goto error;
281		}
282		ret = i2c_smbus_write_word_data(data->client, command, val);
283		if (ret)
284			goto error;
285
286		if (dir == IIO_EV_DIR_RISING)
287			data->high_thresh = val;
288		else
289			data->low_thresh = val;
290		break;
291	case IIO_EV_INFO_PERIOD:
292		period = val * USEC_PER_SEC + val2;
293		for (i = 1; i < ARRAY_SIZE(tcs3472_intr_pers) - 1; i++) {
294			if (period <= (256 - data->atime) * 2400 *
295					tcs3472_intr_pers[i])
296				break;
297		}
298		ret = i2c_smbus_write_byte_data(data->client, TCS3472_PERS, i);
299		if (ret)
300			goto error;
301
302		data->apers = i;
303		break;
304	default:
305		ret = -EINVAL;
306		break;
307	}
308error:
309	mutex_unlock(&data->lock);
310
311	return ret;
312}
313
314static int tcs3472_read_event_config(struct iio_dev *indio_dev,
315	const struct iio_chan_spec *chan, enum iio_event_type type,
316	enum iio_event_direction dir)
317{
318	struct tcs3472_data *data = iio_priv(indio_dev);
319	int ret;
320
321	mutex_lock(&data->lock);
322	ret = !!(data->enable & TCS3472_ENABLE_AIEN);
323	mutex_unlock(&data->lock);
324
325	return ret;
326}
327
328static int tcs3472_write_event_config(struct iio_dev *indio_dev,
329	const struct iio_chan_spec *chan, enum iio_event_type type,
330	enum iio_event_direction dir, int state)
331{
332	struct tcs3472_data *data = iio_priv(indio_dev);
333	int ret = 0;
334	u8 enable_old;
335
336	mutex_lock(&data->lock);
337
338	enable_old = data->enable;
339
340	if (state)
341		data->enable |= TCS3472_ENABLE_AIEN;
342	else
343		data->enable &= ~TCS3472_ENABLE_AIEN;
344
345	if (enable_old != data->enable) {
346		ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
347						data->enable);
348		if (ret)
349			data->enable = enable_old;
350	}
351	mutex_unlock(&data->lock);
352
353	return ret;
354}
355
356static irqreturn_t tcs3472_event_handler(int irq, void *priv)
357{
358	struct iio_dev *indio_dev = priv;
359	struct tcs3472_data *data = iio_priv(indio_dev);
360	int ret;
361
362	ret = i2c_smbus_read_byte_data(data->client, TCS3472_STATUS);
363	if (ret >= 0 && (ret & TCS3472_STATUS_AINT)) {
364		iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
365						IIO_EV_TYPE_THRESH,
366						IIO_EV_DIR_EITHER),
367				iio_get_time_ns(indio_dev));
368
369		i2c_smbus_read_byte_data(data->client, TCS3472_INTR_CLEAR);
370	}
371
372	return IRQ_HANDLED;
373}
374
375static irqreturn_t tcs3472_trigger_handler(int irq, void *p)
376{
377	struct iio_poll_func *pf = p;
378	struct iio_dev *indio_dev = pf->indio_dev;
379	struct tcs3472_data *data = iio_priv(indio_dev);
380	int i, j = 0;
381
382	int ret = tcs3472_req_data(data);
383	if (ret < 0)
384		goto done;
385
386	for_each_set_bit(i, indio_dev->active_scan_mask,
387		indio_dev->masklength) {
388		ret = i2c_smbus_read_word_data(data->client,
389			TCS3472_CDATA + 2*i);
390		if (ret < 0)
391			goto done;
392
393		data->scan.chans[j++] = ret;
394	}
395
396	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
397		iio_get_time_ns(indio_dev));
398
399done:
400	iio_trigger_notify_done(indio_dev->trig);
401
402	return IRQ_HANDLED;
403}
404
405static ssize_t tcs3472_show_int_time_available(struct device *dev,
406					struct device_attribute *attr,
407					char *buf)
408{
409	size_t len = 0;
410	int i;
411
412	for (i = 1; i <= 256; i++)
413		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06d ",
414			2400 * i);
415
416	/* replace trailing space by newline */
417	buf[len - 1] = '\n';
418
419	return len;
420}
421
422static IIO_CONST_ATTR(calibscale_available, "1 4 16 60");
423static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available);
424
425static struct attribute *tcs3472_attributes[] = {
426	&iio_const_attr_calibscale_available.dev_attr.attr,
427	&iio_dev_attr_integration_time_available.dev_attr.attr,
428	NULL
429};
430
431static const struct attribute_group tcs3472_attribute_group = {
432	.attrs = tcs3472_attributes,
433};
434
435static const struct iio_info tcs3472_info = {
436	.read_raw = tcs3472_read_raw,
437	.write_raw = tcs3472_write_raw,
438	.read_event_value = tcs3472_read_event,
439	.write_event_value = tcs3472_write_event,
440	.read_event_config = tcs3472_read_event_config,
441	.write_event_config = tcs3472_write_event_config,
442	.attrs = &tcs3472_attribute_group,
443};
444
445static int tcs3472_probe(struct i2c_client *client,
446			   const struct i2c_device_id *id)
447{
448	struct tcs3472_data *data;
449	struct iio_dev *indio_dev;
450	int ret;
451
452	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
453	if (indio_dev == NULL)
454		return -ENOMEM;
455
456	data = iio_priv(indio_dev);
457	i2c_set_clientdata(client, indio_dev);
458	data->client = client;
459	mutex_init(&data->lock);
460
461	indio_dev->info = &tcs3472_info;
462	indio_dev->name = TCS3472_DRV_NAME;
463	indio_dev->channels = tcs3472_channels;
464	indio_dev->num_channels = ARRAY_SIZE(tcs3472_channels);
465	indio_dev->modes = INDIO_DIRECT_MODE;
466
467	ret = i2c_smbus_read_byte_data(data->client, TCS3472_ID);
468	if (ret < 0)
469		return ret;
470
471	if (ret == 0x44)
472		dev_info(&client->dev, "TCS34721/34725 found\n");
473	else if (ret == 0x4d)
474		dev_info(&client->dev, "TCS34723/34727 found\n");
475	else
476		return -ENODEV;
477
478	ret = i2c_smbus_read_byte_data(data->client, TCS3472_CONTROL);
479	if (ret < 0)
480		return ret;
481	data->control = ret;
482
483	ret = i2c_smbus_read_byte_data(data->client, TCS3472_ATIME);
484	if (ret < 0)
485		return ret;
486	data->atime = ret;
487
488	ret = i2c_smbus_read_word_data(data->client, TCS3472_AILT);
489	if (ret < 0)
490		return ret;
491	data->low_thresh = ret;
492
493	ret = i2c_smbus_read_word_data(data->client, TCS3472_AIHT);
494	if (ret < 0)
495		return ret;
496	data->high_thresh = ret;
497
498	data->apers = 1;
499	ret = i2c_smbus_write_byte_data(data->client, TCS3472_PERS,
500					data->apers);
501	if (ret < 0)
502		return ret;
503
504	ret = i2c_smbus_read_byte_data(data->client, TCS3472_ENABLE);
505	if (ret < 0)
506		return ret;
507
508	/* enable device */
509	data->enable = ret | TCS3472_ENABLE_PON | TCS3472_ENABLE_AEN;
510	data->enable &= ~TCS3472_ENABLE_AIEN;
511	ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
512		data->enable);
513	if (ret < 0)
514		return ret;
515
516	ret = iio_triggered_buffer_setup(indio_dev, NULL,
517		tcs3472_trigger_handler, NULL);
518	if (ret < 0)
519		return ret;
520
521	if (client->irq) {
522		ret = request_threaded_irq(client->irq, NULL,
523					   tcs3472_event_handler,
524					   IRQF_TRIGGER_FALLING | IRQF_SHARED |
525					   IRQF_ONESHOT,
526					   client->name, indio_dev);
527		if (ret)
528			goto buffer_cleanup;
529	}
530
531	ret = iio_device_register(indio_dev);
532	if (ret < 0)
533		goto free_irq;
534
535	return 0;
536
537free_irq:
538	if (client->irq)
539		free_irq(client->irq, indio_dev);
540buffer_cleanup:
541	iio_triggered_buffer_cleanup(indio_dev);
542	return ret;
543}
544
545static int tcs3472_powerdown(struct tcs3472_data *data)
546{
547	int ret;
548	u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;
549
550	mutex_lock(&data->lock);
551
552	ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
553		data->enable & ~enable_mask);
554	if (!ret)
555		data->enable &= ~enable_mask;
556
557	mutex_unlock(&data->lock);
558
559	return ret;
560}
561
562static int tcs3472_remove(struct i2c_client *client)
563{
564	struct iio_dev *indio_dev = i2c_get_clientdata(client);
565
566	iio_device_unregister(indio_dev);
567	if (client->irq)
568		free_irq(client->irq, indio_dev);
569	iio_triggered_buffer_cleanup(indio_dev);
570	tcs3472_powerdown(iio_priv(indio_dev));
571
572	return 0;
573}
574
575#ifdef CONFIG_PM_SLEEP
576static int tcs3472_suspend(struct device *dev)
577{
578	struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
579		to_i2c_client(dev)));
580	return tcs3472_powerdown(data);
581}
582
583static int tcs3472_resume(struct device *dev)
584{
585	struct tcs3472_data *data = iio_priv(i2c_get_clientdata(
586		to_i2c_client(dev)));
587	int ret;
588	u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;
589
590	mutex_lock(&data->lock);
591
592	ret = i2c_smbus_write_byte_data(data->client, TCS3472_ENABLE,
593		data->enable | enable_mask);
594	if (!ret)
595		data->enable |= enable_mask;
596
597	mutex_unlock(&data->lock);
598
599	return ret;
600}
601#endif
602
603static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume);
604
605static const struct i2c_device_id tcs3472_id[] = {
606	{ "tcs3472", 0 },
607	{ }
608};
609MODULE_DEVICE_TABLE(i2c, tcs3472_id);
610
611static struct i2c_driver tcs3472_driver = {
612	.driver = {
613		.name	= TCS3472_DRV_NAME,
614		.pm	= &tcs3472_pm_ops,
615	},
616	.probe		= tcs3472_probe,
617	.remove		= tcs3472_remove,
618	.id_table	= tcs3472_id,
619};
620module_i2c_driver(tcs3472_driver);
621
622MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
623MODULE_DESCRIPTION("TCS3472 color light sensors driver");
624MODULE_LICENSE("GPL");