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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	u16 buffer[8]; /* 4 16-bit channels + 64-bit timestamp */
 68};
 69
 70static 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
106static const int tcs3472_agains[] = { 1, 4, 16, 60 };
107
108static 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
116static 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
138static 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
173static 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 */
215static const int tcs3472_intr_pers[] = {
216	0, 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60
217};
218
219static 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
253static 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	}
304error:
305	mutex_unlock(&data->lock);
306
307	return ret;
308}
309
310static 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
324static 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
352static 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
371static 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
395done:
396	iio_trigger_notify_done(indio_dev->trig);
397
398	return IRQ_HANDLED;
399}
400
401static 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
418static IIO_CONST_ATTR(calibscale_available, "1 4 16 60");
419static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available);
420
421static 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
427static const struct attribute_group tcs3472_attribute_group = {
428	.attrs = tcs3472_attributes,
429};
430
431static 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
441static 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
534free_irq:
535	free_irq(client->irq, indio_dev);
536buffer_cleanup:
537	iio_triggered_buffer_cleanup(indio_dev);
538	return ret;
539}
540
541static 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
558static 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
571static 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
578static 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
598static SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend, tcs3472_resume);
599
600static const struct i2c_device_id tcs3472_id[] = {
601	{ "tcs3472", 0 },
602	{ }
603};
604MODULE_DEVICE_TABLE(i2c, tcs3472_id);
605
606static 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};
615module_i2c_driver(tcs3472_driver);
616
617MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
618MODULE_DESCRIPTION("TCS3472 color light sensors driver");
619MODULE_LICENSE("GPL");