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 aligned_s64 timestamp;
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(client: data->client, TCS3472_STATUS);
127 if (ret < 0)
128 return ret;
129 if (ret & TCS3472_STATUS_AVALID)
130 break;
131 msleep(msecs: 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 if (!iio_device_claim_direct(indio_dev))
152 return -EBUSY;
153 ret = tcs3472_req_data(data);
154 if (ret < 0) {
155 iio_device_release_direct(indio_dev);
156 return ret;
157 }
158 ret = i2c_smbus_read_word_data(client: data->client, command: chan->address);
159 iio_device_release_direct(indio_dev);
160 if (ret < 0)
161 return ret;
162 *val = ret;
163 return IIO_VAL_INT;
164 case IIO_CHAN_INFO_CALIBSCALE:
165 *val = tcs3472_agains[data->control &
166 TCS3472_CONTROL_AGAIN_MASK];
167 return IIO_VAL_INT;
168 case IIO_CHAN_INFO_INT_TIME:
169 *val = 0;
170 *val2 = (256 - data->atime) * 2400;
171 return IIO_VAL_INT_PLUS_MICRO;
172 }
173 return -EINVAL;
174}
175
176static int tcs3472_write_raw(struct iio_dev *indio_dev,
177 struct iio_chan_spec const *chan,
178 int val, int val2, long mask)
179{
180 struct tcs3472_data *data = iio_priv(indio_dev);
181 int i;
182
183 switch (mask) {
184 case IIO_CHAN_INFO_CALIBSCALE:
185 if (val2 != 0)
186 return -EINVAL;
187 for (i = 0; i < ARRAY_SIZE(tcs3472_agains); i++) {
188 if (val == tcs3472_agains[i]) {
189 data->control &= ~TCS3472_CONTROL_AGAIN_MASK;
190 data->control |= i;
191 return i2c_smbus_write_byte_data(
192 client: data->client, TCS3472_CONTROL,
193 value: data->control);
194 }
195 }
196 return -EINVAL;
197 case IIO_CHAN_INFO_INT_TIME:
198 if (val != 0)
199 return -EINVAL;
200 for (i = 0; i < 256; i++) {
201 if (val2 == (256 - i) * 2400) {
202 data->atime = i;
203 return i2c_smbus_write_byte_data(
204 client: data->client, TCS3472_ATIME,
205 value: data->atime);
206 }
207
208 }
209 return -EINVAL;
210 }
211 return -EINVAL;
212}
213
214/*
215 * Translation from APERS field value to the number of consecutive out-of-range
216 * clear channel values before an interrupt is generated
217 */
218static const int tcs3472_intr_pers[] = {
219 0, 1, 2, 3, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60
220};
221
222static int tcs3472_read_event(struct iio_dev *indio_dev,
223 const struct iio_chan_spec *chan, enum iio_event_type type,
224 enum iio_event_direction dir, enum iio_event_info info, int *val,
225 int *val2)
226{
227 struct tcs3472_data *data = iio_priv(indio_dev);
228 int ret;
229 unsigned int period;
230
231 mutex_lock(&data->lock);
232
233 switch (info) {
234 case IIO_EV_INFO_VALUE:
235 *val = (dir == IIO_EV_DIR_RISING) ?
236 data->high_thresh : data->low_thresh;
237 ret = IIO_VAL_INT;
238 break;
239 case IIO_EV_INFO_PERIOD:
240 period = (256 - data->atime) * 2400 *
241 tcs3472_intr_pers[data->apers];
242 *val = period / USEC_PER_SEC;
243 *val2 = period % USEC_PER_SEC;
244 ret = IIO_VAL_INT_PLUS_MICRO;
245 break;
246 default:
247 ret = -EINVAL;
248 break;
249 }
250
251 mutex_unlock(lock: &data->lock);
252
253 return ret;
254}
255
256static int tcs3472_write_event(struct iio_dev *indio_dev,
257 const struct iio_chan_spec *chan, enum iio_event_type type,
258 enum iio_event_direction dir, enum iio_event_info info, int val,
259 int val2)
260{
261 struct tcs3472_data *data = iio_priv(indio_dev);
262 int ret;
263 u8 command;
264 int period;
265 int i;
266
267 mutex_lock(&data->lock);
268 switch (info) {
269 case IIO_EV_INFO_VALUE:
270 switch (dir) {
271 case IIO_EV_DIR_RISING:
272 command = TCS3472_AIHT;
273 break;
274 case IIO_EV_DIR_FALLING:
275 command = TCS3472_AILT;
276 break;
277 default:
278 ret = -EINVAL;
279 goto error;
280 }
281 ret = i2c_smbus_write_word_data(client: data->client, command, value: val);
282 if (ret)
283 goto error;
284
285 if (dir == IIO_EV_DIR_RISING)
286 data->high_thresh = val;
287 else
288 data->low_thresh = val;
289 break;
290 case IIO_EV_INFO_PERIOD:
291 period = val * USEC_PER_SEC + val2;
292 for (i = 1; i < ARRAY_SIZE(tcs3472_intr_pers) - 1; i++) {
293 if (period <= (256 - data->atime) * 2400 *
294 tcs3472_intr_pers[i])
295 break;
296 }
297 ret = i2c_smbus_write_byte_data(client: data->client, TCS3472_PERS, value: i);
298 if (ret)
299 goto error;
300
301 data->apers = i;
302 break;
303 default:
304 ret = -EINVAL;
305 break;
306 }
307error:
308 mutex_unlock(lock: &data->lock);
309
310 return ret;
311}
312
313static int tcs3472_read_event_config(struct iio_dev *indio_dev,
314 const struct iio_chan_spec *chan, enum iio_event_type type,
315 enum iio_event_direction dir)
316{
317 struct tcs3472_data *data = iio_priv(indio_dev);
318 int ret;
319
320 mutex_lock(&data->lock);
321 ret = !!(data->enable & TCS3472_ENABLE_AIEN);
322 mutex_unlock(lock: &data->lock);
323
324 return ret;
325}
326
327static int tcs3472_write_event_config(struct iio_dev *indio_dev,
328 const struct iio_chan_spec *chan, enum iio_event_type type,
329 enum iio_event_direction dir, bool state)
330{
331 struct tcs3472_data *data = iio_priv(indio_dev);
332 int ret = 0;
333 u8 enable_old;
334
335 mutex_lock(&data->lock);
336
337 enable_old = data->enable;
338
339 if (state)
340 data->enable |= TCS3472_ENABLE_AIEN;
341 else
342 data->enable &= ~TCS3472_ENABLE_AIEN;
343
344 if (enable_old != data->enable) {
345 ret = i2c_smbus_write_byte_data(client: data->client, TCS3472_ENABLE,
346 value: data->enable);
347 if (ret)
348 data->enable = enable_old;
349 }
350 mutex_unlock(lock: &data->lock);
351
352 return ret;
353}
354
355static irqreturn_t tcs3472_event_handler(int irq, void *priv)
356{
357 struct iio_dev *indio_dev = priv;
358 struct tcs3472_data *data = iio_priv(indio_dev);
359 int ret;
360
361 ret = i2c_smbus_read_byte_data(client: data->client, TCS3472_STATUS);
362 if (ret >= 0 && (ret & TCS3472_STATUS_AINT)) {
363 iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
364 IIO_EV_TYPE_THRESH,
365 IIO_EV_DIR_EITHER),
366 timestamp: iio_get_time_ns(indio_dev));
367
368 i2c_smbus_read_byte_data(client: data->client, TCS3472_INTR_CLEAR);
369 }
370
371 return IRQ_HANDLED;
372}
373
374static irqreturn_t tcs3472_trigger_handler(int irq, void *p)
375{
376 struct iio_poll_func *pf = p;
377 struct iio_dev *indio_dev = pf->indio_dev;
378 struct tcs3472_data *data = iio_priv(indio_dev);
379 int i, j = 0;
380
381 int ret = tcs3472_req_data(data);
382 if (ret < 0)
383 goto done;
384
385 iio_for_each_active_channel(indio_dev, i) {
386 ret = i2c_smbus_read_word_data(client: data->client,
387 TCS3472_CDATA + 2*i);
388 if (ret < 0)
389 goto done;
390
391 data->scan.chans[j++] = ret;
392 }
393
394 iio_push_to_buffers_with_timestamp(indio_dev, data: &data->scan,
395 timestamp: iio_get_time_ns(indio_dev));
396
397done:
398 iio_trigger_notify_done(trig: indio_dev->trig);
399
400 return IRQ_HANDLED;
401}
402
403static ssize_t tcs3472_show_int_time_available(struct device *dev,
404 struct device_attribute *attr,
405 char *buf)
406{
407 size_t len = 0;
408 int i;
409
410 for (i = 1; i <= 256; i++)
411 len += scnprintf(buf: buf + len, PAGE_SIZE - len, fmt: "0.%06d ",
412 2400 * i);
413
414 /* replace trailing space by newline */
415 buf[len - 1] = '\n';
416
417 return len;
418}
419
420static IIO_CONST_ATTR(calibscale_available, "1 4 16 60");
421static IIO_DEV_ATTR_INT_TIME_AVAIL(tcs3472_show_int_time_available);
422
423static struct attribute *tcs3472_attributes[] = {
424 &iio_const_attr_calibscale_available.dev_attr.attr,
425 &iio_dev_attr_integration_time_available.dev_attr.attr,
426 NULL
427};
428
429static const struct attribute_group tcs3472_attribute_group = {
430 .attrs = tcs3472_attributes,
431};
432
433static const struct iio_info tcs3472_info = {
434 .read_raw = tcs3472_read_raw,
435 .write_raw = tcs3472_write_raw,
436 .read_event_value = tcs3472_read_event,
437 .write_event_value = tcs3472_write_event,
438 .read_event_config = tcs3472_read_event_config,
439 .write_event_config = tcs3472_write_event_config,
440 .attrs = &tcs3472_attribute_group,
441};
442
443static int tcs3472_probe(struct i2c_client *client)
444{
445 struct tcs3472_data *data;
446 struct iio_dev *indio_dev;
447 int ret;
448
449 indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*data));
450 if (indio_dev == NULL)
451 return -ENOMEM;
452
453 data = iio_priv(indio_dev);
454 i2c_set_clientdata(client, data: indio_dev);
455 data->client = client;
456 mutex_init(&data->lock);
457
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(client: 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(client: data->client, TCS3472_CONTROL);
476 if (ret < 0)
477 return ret;
478 data->control = ret;
479
480 ret = i2c_smbus_read_byte_data(client: data->client, TCS3472_ATIME);
481 if (ret < 0)
482 return ret;
483 data->atime = ret;
484
485 ret = i2c_smbus_read_word_data(client: data->client, TCS3472_AILT);
486 if (ret < 0)
487 return ret;
488 data->low_thresh = ret;
489
490 ret = i2c_smbus_read_word_data(client: 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(client: data->client, TCS3472_PERS,
497 value: data->apers);
498 if (ret < 0)
499 return ret;
500
501 ret = i2c_smbus_read_byte_data(client: 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(client: data->client, TCS3472_ENABLE,
509 value: 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(irq: client->irq, NULL,
520 thread_fn: tcs3472_event_handler,
521 IRQF_TRIGGER_FALLING | IRQF_SHARED |
522 IRQF_ONESHOT,
523 name: client->name, dev: 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 if (client->irq)
536 free_irq(client->irq, indio_dev);
537buffer_cleanup:
538 iio_triggered_buffer_cleanup(indio_dev);
539 return ret;
540}
541
542static int tcs3472_powerdown(struct tcs3472_data *data)
543{
544 int ret;
545 u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;
546
547 mutex_lock(&data->lock);
548
549 ret = i2c_smbus_write_byte_data(client: data->client, TCS3472_ENABLE,
550 value: data->enable & ~enable_mask);
551 if (!ret)
552 data->enable &= ~enable_mask;
553
554 mutex_unlock(lock: &data->lock);
555
556 return ret;
557}
558
559static void tcs3472_remove(struct i2c_client *client)
560{
561 struct iio_dev *indio_dev = i2c_get_clientdata(client);
562
563 iio_device_unregister(indio_dev);
564 if (client->irq)
565 free_irq(client->irq, indio_dev);
566 iio_triggered_buffer_cleanup(indio_dev);
567 tcs3472_powerdown(data: iio_priv(indio_dev));
568}
569
570static int tcs3472_suspend(struct device *dev)
571{
572 struct tcs3472_data *data = iio_priv(indio_dev: i2c_get_clientdata(
573 to_i2c_client(dev)));
574 return tcs3472_powerdown(data);
575}
576
577static int tcs3472_resume(struct device *dev)
578{
579 struct tcs3472_data *data = iio_priv(indio_dev: i2c_get_clientdata(
580 to_i2c_client(dev)));
581 int ret;
582 u8 enable_mask = TCS3472_ENABLE_AEN | TCS3472_ENABLE_PON;
583
584 mutex_lock(&data->lock);
585
586 ret = i2c_smbus_write_byte_data(client: data->client, TCS3472_ENABLE,
587 value: data->enable | enable_mask);
588 if (!ret)
589 data->enable |= enable_mask;
590
591 mutex_unlock(lock: &data->lock);
592
593 return ret;
594}
595
596static DEFINE_SIMPLE_DEV_PM_OPS(tcs3472_pm_ops, tcs3472_suspend,
597 tcs3472_resume);
598
599static const struct i2c_device_id tcs3472_id[] = {
600 { "tcs3472" },
601 { }
602};
603MODULE_DEVICE_TABLE(i2c, tcs3472_id);
604
605static struct i2c_driver tcs3472_driver = {
606 .driver = {
607 .name = TCS3472_DRV_NAME,
608 .pm = pm_sleep_ptr(&tcs3472_pm_ops),
609 },
610 .probe = tcs3472_probe,
611 .remove = tcs3472_remove,
612 .id_table = tcs3472_id,
613};
614module_i2c_driver(tcs3472_driver);
615
616MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
617MODULE_DESCRIPTION("TCS3472 color light sensors driver");
618MODULE_LICENSE("GPL");
619

source code of linux/drivers/iio/light/tcs3472.c