summaryrefslogtreecommitdiff
path: root/drivers/iio/light/zopt2201.c
blob: 604be60e92acae020acdbd274a599726e31983f8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
// SPDX-License-Identifier: GPL-2.0-only
/*
 * zopt2201.c - Support for IDT ZOPT2201 ambient light and UV B sensor
 *
 * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
 *
 * Datasheet: https://www.idt.com/document/dst/zopt2201-datasheet
 * 7-bit I2C slave addresses 0x53 (default) or 0x52 (programmed)
 *
 * TODO: interrupt support, ALS/UVB raw mode
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/delay.h>

#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

#include <linux/unaligned.h>

#define ZOPT2201_DRV_NAME "zopt2201"

/* Registers */
#define ZOPT2201_MAIN_CTRL		0x00
#define ZOPT2201_LS_MEAS_RATE		0x04
#define ZOPT2201_LS_GAIN		0x05
#define ZOPT2201_PART_ID		0x06
#define ZOPT2201_MAIN_STATUS		0x07
#define ZOPT2201_ALS_DATA		0x0d /* LSB first, 13 to 20 bits */
#define ZOPT2201_UVB_DATA		0x10 /* LSB first, 13 to 20 bits */
#define ZOPT2201_UV_COMP_DATA		0x13 /* LSB first, 13 to 20 bits */
#define ZOPT2201_COMP_DATA		0x16 /* LSB first, 13 to 20 bits */
#define ZOPT2201_INT_CFG		0x19
#define ZOPT2201_INT_PST		0x1a

#define ZOPT2201_MAIN_CTRL_LS_MODE	BIT(3) /* 0 .. ALS, 1 .. UV B */
#define ZOPT2201_MAIN_CTRL_LS_EN	BIT(1)

/* Values for ZOPT2201_LS_MEAS_RATE resolution / bit width */
#define ZOPT2201_MEAS_RES_20BIT		0 /* takes 400 ms */
#define ZOPT2201_MEAS_RES_19BIT		1 /* takes 200 ms */
#define ZOPT2201_MEAS_RES_18BIT		2 /* takes 100 ms, default */
#define ZOPT2201_MEAS_RES_17BIT		3 /* takes 50 ms */
#define ZOPT2201_MEAS_RES_16BIT		4 /* takes 25 ms */
#define ZOPT2201_MEAS_RES_13BIT		5 /* takes 3.125 ms */
#define ZOPT2201_MEAS_RES_SHIFT		4

/* Values for ZOPT2201_LS_MEAS_RATE measurement rate */
#define ZOPT2201_MEAS_FREQ_25MS		0
#define ZOPT2201_MEAS_FREQ_50MS		1
#define ZOPT2201_MEAS_FREQ_100MS	2 /* default */
#define ZOPT2201_MEAS_FREQ_200MS	3
#define ZOPT2201_MEAS_FREQ_500MS	4
#define ZOPT2201_MEAS_FREQ_1000MS	5
#define ZOPT2201_MEAS_FREQ_2000MS	6

/* Values for ZOPT2201_LS_GAIN */
#define ZOPT2201_LS_GAIN_1		0
#define ZOPT2201_LS_GAIN_3		1
#define ZOPT2201_LS_GAIN_6		2
#define ZOPT2201_LS_GAIN_9		3
#define ZOPT2201_LS_GAIN_18		4

/* Values for ZOPT2201_MAIN_STATUS */
#define ZOPT2201_MAIN_STATUS_POWERON	BIT(5)
#define ZOPT2201_MAIN_STATUS_INT	BIT(4)
#define ZOPT2201_MAIN_STATUS_DRDY	BIT(3)

#define ZOPT2201_PART_NUMBER		0xb2

struct zopt2201_data {
	struct i2c_client *client;
	struct mutex lock;
	u8 gain;
	u8 res;
	u8 rate;
};

static const struct {
	unsigned int gain; /* gain factor */
	unsigned int scale; /* micro lux per count */
} zopt2201_gain_als[] = {
	{  1, 19200000 },
	{  3,  6400000 },
	{  6,  3200000 },
	{  9,  2133333 },
	{ 18,  1066666 },
};

static const struct {
	unsigned int gain; /* gain factor */
	unsigned int scale; /* micro W/m2 per count */
} zopt2201_gain_uvb[] = {
	{  1, 460800 },
	{  3, 153600 },
	{  6,  76800 },
	{  9,  51200 },
	{ 18,  25600 },
};

static const struct {
	unsigned int bits; /* sensor resolution in bits */
	unsigned long us; /* measurement time in micro seconds */
} zopt2201_resolution[] = {
	{ 20, 400000 },
	{ 19, 200000 },
	{ 18, 100000 },
	{ 17,  50000 },
	{ 16,  25000 },
	{ 13,   3125 },
};

static const struct {
	unsigned int scale, uscale; /* scale factor as integer + micro */
	u8 gain; /* gain register value */
	u8 res; /* resolution register value */
} zopt2201_scale_als[] = {
	{ 19, 200000, 0, 5 },
	{  6, 400000, 1, 5 },
	{  3, 200000, 2, 5 },
	{  2, 400000, 0, 4 },
	{  2, 133333, 3, 5 },
	{  1, 200000, 0, 3 },
	{  1,  66666, 4, 5 },
	{  0, 800000, 1, 4 },
	{  0, 600000, 0, 2 },
	{  0, 400000, 2, 4 },
	{  0, 300000, 0, 1 },
	{  0, 266666, 3, 4 },
	{  0, 200000, 2, 3 },
	{  0, 150000, 0, 0 },
	{  0, 133333, 4, 4 },
	{  0, 100000, 2, 2 },
	{  0,  66666, 4, 3 },
	{  0,  50000, 2, 1 },
	{  0,  33333, 4, 2 },
	{  0,  25000, 2, 0 },
	{  0,  16666, 4, 1 },
	{  0,   8333, 4, 0 },
};

static const struct {
	unsigned int scale, uscale; /* scale factor as integer + micro */
	u8 gain; /* gain register value */
	u8 res; /* resolution register value */
} zopt2201_scale_uvb[] = {
	{ 0, 460800, 0, 5 },
	{ 0, 153600, 1, 5 },
	{ 0,  76800, 2, 5 },
	{ 0,  57600, 0, 4 },
	{ 0,  51200, 3, 5 },
	{ 0,  28800, 0, 3 },
	{ 0,  25600, 4, 5 },
	{ 0,  19200, 1, 4 },
	{ 0,  14400, 0, 2 },
	{ 0,   9600, 2, 4 },
	{ 0,   7200, 0, 1 },
	{ 0,   6400, 3, 4 },
	{ 0,   4800, 2, 3 },
	{ 0,   3600, 0, 0 },
	{ 0,   3200, 4, 4 },
	{ 0,   2400, 2, 2 },
	{ 0,   1600, 4, 3 },
	{ 0,   1200, 2, 1 },
	{ 0,    800, 4, 2 },
	{ 0,    600, 2, 0 },
	{ 0,    400, 4, 1 },
	{ 0,    200, 4, 0 },
};

static int zopt2201_enable_mode(struct zopt2201_data *data, bool uvb_mode)
{
	u8 out = ZOPT2201_MAIN_CTRL_LS_EN;

	if (uvb_mode)
		out |= ZOPT2201_MAIN_CTRL_LS_MODE;

	return i2c_smbus_write_byte_data(data->client, ZOPT2201_MAIN_CTRL, out);
}

static int zopt2201_read(struct zopt2201_data *data, u8 reg)
{
	struct i2c_client *client = data->client;
	int tries = 10;
	u8 buf[3];
	int ret;

	mutex_lock(&data->lock);
	ret = zopt2201_enable_mode(data, reg == ZOPT2201_UVB_DATA);
	if (ret < 0)
		goto fail;

	while (tries--) {
		unsigned long t = zopt2201_resolution[data->res].us;

		if (t <= 20000)
			usleep_range(t, t + 1000);
		else
			msleep(t / 1000);
		ret = i2c_smbus_read_byte_data(client, ZOPT2201_MAIN_STATUS);
		if (ret < 0)
			goto fail;
		if (ret & ZOPT2201_MAIN_STATUS_DRDY)
			break;
	}

	if (tries < 0) {
		ret = -ETIMEDOUT;
		goto fail;
	}

	ret = i2c_smbus_read_i2c_block_data(client, reg, sizeof(buf), buf);
	if (ret < 0)
		goto fail;

	ret = i2c_smbus_write_byte_data(client, ZOPT2201_MAIN_CTRL, 0x00);
	if (ret < 0)
		goto fail;
	mutex_unlock(&data->lock);

	return get_unaligned_le24(&buf[0]);

fail:
	mutex_unlock(&data->lock);
	return ret;
}

static const struct iio_chan_spec zopt2201_channels[] = {
	{
		.type = IIO_LIGHT,
		.address = ZOPT2201_ALS_DATA,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_SCALE),
		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
	},
	{
		.type = IIO_INTENSITY,
		.modified = 1,
		.channel2 = IIO_MOD_LIGHT_UV,
		.address = ZOPT2201_UVB_DATA,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
				      BIT(IIO_CHAN_INFO_SCALE),
		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
	},
	{
		.type = IIO_UVINDEX,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
	},
};

static int zopt2201_read_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int *val, int *val2, long mask)
{
	struct zopt2201_data *data = iio_priv(indio_dev);
	u64 tmp;
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = zopt2201_read(data, chan->address);
		if (ret < 0)
			return ret;
		*val = ret;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_PROCESSED:
		ret = zopt2201_read(data, ZOPT2201_UVB_DATA);
		if (ret < 0)
			return ret;
		*val = ret * 18 *
			(1 << (20 - zopt2201_resolution[data->res].bits)) /
			zopt2201_gain_uvb[data->gain].gain;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		switch (chan->address) {
		case ZOPT2201_ALS_DATA:
			*val = zopt2201_gain_als[data->gain].scale;
			break;
		case ZOPT2201_UVB_DATA:
			*val = zopt2201_gain_uvb[data->gain].scale;
			break;
		default:
			return -EINVAL;
		}

		*val2 = 1000000;
		*val2 *= (1 << (zopt2201_resolution[data->res].bits - 13));
		tmp = div_s64(*val * 1000000ULL, *val2);
		*val = div_s64_rem(tmp, 1000000, val2);

		return IIO_VAL_INT_PLUS_MICRO;
	case IIO_CHAN_INFO_INT_TIME:
		*val = 0;
		*val2 = zopt2201_resolution[data->res].us;
		return IIO_VAL_INT_PLUS_MICRO;
	default:
		return -EINVAL;
	}
}

static int zopt2201_set_resolution(struct zopt2201_data *data, u8 res)
{
	int ret;

	ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_MEAS_RATE,
					(res << ZOPT2201_MEAS_RES_SHIFT) |
					data->rate);
	if (ret < 0)
		return ret;

	data->res = res;

	return 0;
}

static int zopt2201_write_resolution(struct zopt2201_data *data,
				     int val, int val2)
{
	int i, ret;

	if (val != 0)
		return -EINVAL;

	for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
		if (val2 == zopt2201_resolution[i].us) {
			mutex_lock(&data->lock);
			ret = zopt2201_set_resolution(data, i);
			mutex_unlock(&data->lock);
			return ret;
		}

	return -EINVAL;
}

static int zopt2201_set_gain(struct zopt2201_data *data, u8 gain)
{
	int ret;

	ret = i2c_smbus_write_byte_data(data->client, ZOPT2201_LS_GAIN, gain);
	if (ret < 0)
		return ret;

	data->gain = gain;

	return 0;
}

static int zopt2201_write_scale_als_by_idx(struct zopt2201_data *data, int idx)
{
	int ret;

	mutex_lock(&data->lock);
	ret = zopt2201_set_resolution(data, zopt2201_scale_als[idx].res);
	if (ret < 0)
		goto unlock;

	ret = zopt2201_set_gain(data, zopt2201_scale_als[idx].gain);

unlock:
	mutex_unlock(&data->lock);
	return ret;
}

static int zopt2201_write_scale_als(struct zopt2201_data *data,
				     int val, int val2)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
		if (val == zopt2201_scale_als[i].scale &&
		    val2 == zopt2201_scale_als[i].uscale) {
			return zopt2201_write_scale_als_by_idx(data, i);
		}

	return -EINVAL;
}

static int zopt2201_write_scale_uvb_by_idx(struct zopt2201_data *data, int idx)
{
	int ret;

	mutex_lock(&data->lock);
	ret = zopt2201_set_resolution(data, zopt2201_scale_als[idx].res);
	if (ret < 0)
		goto unlock;

	ret = zopt2201_set_gain(data, zopt2201_scale_als[idx].gain);

unlock:
	mutex_unlock(&data->lock);
	return ret;
}

static int zopt2201_write_scale_uvb(struct zopt2201_data *data,
				     int val, int val2)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
		if (val == zopt2201_scale_uvb[i].scale &&
		    val2 == zopt2201_scale_uvb[i].uscale)
			return zopt2201_write_scale_uvb_by_idx(data, i);

	return -EINVAL;
}

static int zopt2201_write_raw(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan,
			      int val, int val2, long mask)
{
	struct zopt2201_data *data = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_INT_TIME:
		return zopt2201_write_resolution(data, val, val2);
	case IIO_CHAN_INFO_SCALE:
		switch (chan->address) {
		case ZOPT2201_ALS_DATA:
			return zopt2201_write_scale_als(data, val, val2);
		case ZOPT2201_UVB_DATA:
			return zopt2201_write_scale_uvb(data, val, val2);
		default:
			return -EINVAL;
		}
	}

	return -EINVAL;
}

static ssize_t zopt2201_show_int_time_available(struct device *dev,
						struct device_attribute *attr,
						char *buf)
{
	size_t len = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(zopt2201_resolution); i++)
		len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06lu ",
				 zopt2201_resolution[i].us);
	buf[len - 1] = '\n';

	return len;
}

static IIO_DEV_ATTR_INT_TIME_AVAIL(zopt2201_show_int_time_available);

static ssize_t zopt2201_show_als_scale_avail(struct device *dev,
					     struct device_attribute *attr,
					     char *buf)
{
	ssize_t len = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(zopt2201_scale_als); i++)
		len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
				 zopt2201_scale_als[i].scale,
				 zopt2201_scale_als[i].uscale);
	buf[len - 1] = '\n';

	return len;
}

static ssize_t zopt2201_show_uvb_scale_avail(struct device *dev,
					     struct device_attribute *attr,
					     char *buf)
{
	ssize_t len = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(zopt2201_scale_uvb); i++)
		len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06u ",
				 zopt2201_scale_uvb[i].scale,
				 zopt2201_scale_uvb[i].uscale);
	buf[len - 1] = '\n';

	return len;
}

static IIO_DEVICE_ATTR(in_illuminance_scale_available, 0444,
		       zopt2201_show_als_scale_avail, NULL, 0);
static IIO_DEVICE_ATTR(in_intensity_uv_scale_available, 0444,
		       zopt2201_show_uvb_scale_avail, NULL, 0);

static struct attribute *zopt2201_attributes[] = {
	&iio_dev_attr_integration_time_available.dev_attr.attr,
	&iio_dev_attr_in_illuminance_scale_available.dev_attr.attr,
	&iio_dev_attr_in_intensity_uv_scale_available.dev_attr.attr,
	NULL
};

static const struct attribute_group zopt2201_attribute_group = {
	.attrs = zopt2201_attributes,
};

static const struct iio_info zopt2201_info = {
	.read_raw = zopt2201_read_raw,
	.write_raw = zopt2201_write_raw,
	.attrs = &zopt2201_attribute_group,
};

static int zopt2201_probe(struct i2c_client *client)
{
	struct zopt2201_data *data;
	struct iio_dev *indio_dev;
	int ret;

	if (!i2c_check_functionality(client->adapter,
				     I2C_FUNC_SMBUS_READ_I2C_BLOCK))
		return -EOPNOTSUPP;

	ret = i2c_smbus_read_byte_data(client, ZOPT2201_PART_ID);
	if (ret < 0)
		return ret;
	if (ret != ZOPT2201_PART_NUMBER)
		return -ENODEV;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	if (!indio_dev)
		return -ENOMEM;

	data = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);
	data->client = client;
	mutex_init(&data->lock);

	indio_dev->info = &zopt2201_info;
	indio_dev->channels = zopt2201_channels;
	indio_dev->num_channels = ARRAY_SIZE(zopt2201_channels);
	indio_dev->name = ZOPT2201_DRV_NAME;
	indio_dev->modes = INDIO_DIRECT_MODE;

	data->rate = ZOPT2201_MEAS_FREQ_100MS;
	ret = zopt2201_set_resolution(data, ZOPT2201_MEAS_RES_18BIT);
	if (ret < 0)
		return ret;

	ret = zopt2201_set_gain(data, ZOPT2201_LS_GAIN_3);
	if (ret < 0)
		return ret;

	return devm_iio_device_register(&client->dev, indio_dev);
}

static const struct i2c_device_id zopt2201_id[] = {
	{ "zopt2201" },
	{ }
};
MODULE_DEVICE_TABLE(i2c, zopt2201_id);

static struct i2c_driver zopt2201_driver = {
	.driver = {
		.name   = ZOPT2201_DRV_NAME,
	},
	.probe = zopt2201_probe,
	.id_table = zopt2201_id,
};

module_i2c_driver(zopt2201_driver);

MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("IDT ZOPT2201 ambient light and UV B sensor driver");
MODULE_LICENSE("GPL");