aboutsummaryrefslogtreecommitdiff
path: root/drivers/iio/light/lv0104cs.c
blob: 55b8e2855647731388bf1448fc45c2c7770c5173 (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
// SPDX-License-Identifier: GPL-2.0+
/*
 * lv0104cs.c: LV0104CS Ambient Light Sensor Driver
 *
 * Copyright (C) 2018
 * Author: Jeff LaBundy <jeff@labundy.com>
 *
 * 7-bit I2C slave address: 0x13
 *
 * Link to data sheet: http://www.onsemi.com/pub/Collateral/LV0104CS-D.PDF
 */

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

#define LV0104CS_REGVAL_MEASURE		0xE0
#define LV0104CS_REGVAL_SLEEP		0x00

#define LV0104CS_SCALE_0_25X		0
#define LV0104CS_SCALE_1X		1
#define LV0104CS_SCALE_2X		2
#define LV0104CS_SCALE_8X		3
#define LV0104CS_SCALE_SHIFT		3

#define LV0104CS_INTEG_12_5MS		0
#define LV0104CS_INTEG_100MS		1
#define LV0104CS_INTEG_200MS		2
#define LV0104CS_INTEG_SHIFT		1

#define LV0104CS_CALIBSCALE_UNITY	31

struct lv0104cs_private {
	struct i2c_client *client;
	struct mutex lock;
	u8 calibscale;
	u8 scale;
	u8 int_time;
};

struct lv0104cs_mapping {
	int val;
	int val2;
	u8 regval;
};

static const struct lv0104cs_mapping lv0104cs_calibscales[] = {
	{ 0, 666666, 0x81 },
	{ 0, 800000, 0x82 },
	{ 0, 857142, 0x83 },
	{ 0, 888888, 0x84 },
	{ 0, 909090, 0x85 },
	{ 0, 923076, 0x86 },
	{ 0, 933333, 0x87 },
	{ 0, 941176, 0x88 },
	{ 0, 947368, 0x89 },
	{ 0, 952380, 0x8A },
	{ 0, 956521, 0x8B },
	{ 0, 960000, 0x8C },
	{ 0, 962962, 0x8D },
	{ 0, 965517, 0x8E },
	{ 0, 967741, 0x8F },
	{ 0, 969696, 0x90 },
	{ 0, 971428, 0x91 },
	{ 0, 972972, 0x92 },
	{ 0, 974358, 0x93 },
	{ 0, 975609, 0x94 },
	{ 0, 976744, 0x95 },
	{ 0, 977777, 0x96 },
	{ 0, 978723, 0x97 },
	{ 0, 979591, 0x98 },
	{ 0, 980392, 0x99 },
	{ 0, 981132, 0x9A },
	{ 0, 981818, 0x9B },
	{ 0, 982456, 0x9C },
	{ 0, 983050, 0x9D },
	{ 0, 983606, 0x9E },
	{ 0, 984126, 0x9F },
	{ 1, 0, 0x80 },
	{ 1, 16129, 0xBF },
	{ 1, 16666, 0xBE },
	{ 1, 17241, 0xBD },
	{ 1, 17857, 0xBC },
	{ 1, 18518, 0xBB },
	{ 1, 19230, 0xBA },
	{ 1, 20000, 0xB9 },
	{ 1, 20833, 0xB8 },
	{ 1, 21739, 0xB7 },
	{ 1, 22727, 0xB6 },
	{ 1, 23809, 0xB5 },
	{ 1, 24999, 0xB4 },
	{ 1, 26315, 0xB3 },
	{ 1, 27777, 0xB2 },
	{ 1, 29411, 0xB1 },
	{ 1, 31250, 0xB0 },
	{ 1, 33333, 0xAF },
	{ 1, 35714, 0xAE },
	{ 1, 38461, 0xAD },
	{ 1, 41666, 0xAC },
	{ 1, 45454, 0xAB },
	{ 1, 50000, 0xAA },
	{ 1, 55555, 0xA9 },
	{ 1, 62500, 0xA8 },
	{ 1, 71428, 0xA7 },
	{ 1, 83333, 0xA6 },
	{ 1, 100000, 0xA5 },
	{ 1, 125000, 0xA4 },
	{ 1, 166666, 0xA3 },
	{ 1, 250000, 0xA2 },
	{ 1, 500000, 0xA1 },
};

static const struct lv0104cs_mapping lv0104cs_scales[] = {
	{ 0, 250000, LV0104CS_SCALE_0_25X << LV0104CS_SCALE_SHIFT },
	{ 1, 0, LV0104CS_SCALE_1X << LV0104CS_SCALE_SHIFT },
	{ 2, 0, LV0104CS_SCALE_2X << LV0104CS_SCALE_SHIFT },
	{ 8, 0, LV0104CS_SCALE_8X << LV0104CS_SCALE_SHIFT },
};

static const struct lv0104cs_mapping lv0104cs_int_times[] = {
	{ 0, 12500, LV0104CS_INTEG_12_5MS << LV0104CS_INTEG_SHIFT },
	{ 0, 100000, LV0104CS_INTEG_100MS << LV0104CS_INTEG_SHIFT },
	{ 0, 200000, LV0104CS_INTEG_200MS << LV0104CS_INTEG_SHIFT },
};

static int lv0104cs_write_reg(struct i2c_client *client, u8 regval)
{
	int ret;

	ret = i2c_master_send(client, (char *)&regval, sizeof(regval));
	if (ret < 0)
		return ret;
	if (ret != sizeof(regval))
		return -EIO;

	return 0;
}

static int lv0104cs_read_adc(struct i2c_client *client, u16 *adc_output)
{
	__be16 regval;
	int ret;

	ret = i2c_master_recv(client, (char *)&regval, sizeof(regval));
	if (ret < 0)
		return ret;
	if (ret != sizeof(regval))
		return -EIO;

	*adc_output = be16_to_cpu(regval);

	return 0;
}

static int lv0104cs_get_lux(struct lv0104cs_private *lv0104cs,
				int *val, int *val2)
{
	u8 regval = LV0104CS_REGVAL_MEASURE;
	u16 adc_output;
	int ret;

	regval |= lv0104cs_scales[lv0104cs->scale].regval;
	regval |= lv0104cs_int_times[lv0104cs->int_time].regval;
	ret = lv0104cs_write_reg(lv0104cs->client, regval);
	if (ret)
		return ret;

	/* wait for integration time to pass (with margin) */
	switch (lv0104cs->int_time) {
	case LV0104CS_INTEG_12_5MS:
		msleep(50);
		break;

	case LV0104CS_INTEG_100MS:
		msleep(150);
		break;

	case LV0104CS_INTEG_200MS:
		msleep(250);
		break;

	default:
		return -EINVAL;
	}

	ret = lv0104cs_read_adc(lv0104cs->client, &adc_output);
	if (ret)
		return ret;

	ret = lv0104cs_write_reg(lv0104cs->client, LV0104CS_REGVAL_SLEEP);
	if (ret)
		return ret;

	/* convert ADC output to lux */
	switch (lv0104cs->scale) {
	case LV0104CS_SCALE_0_25X:
		*val = adc_output * 4;
		*val2 = 0;
		return 0;

	case LV0104CS_SCALE_1X:
		*val = adc_output;
		*val2 = 0;
		return 0;

	case LV0104CS_SCALE_2X:
		*val = adc_output / 2;
		*val2 = (adc_output % 2) * 500000;
		return 0;

	case LV0104CS_SCALE_8X:
		*val = adc_output / 8;
		*val2 = (adc_output % 8) * 125000;
		return 0;

	default:
		return -EINVAL;
	}
}

static int lv0104cs_read_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int *val, int *val2, long mask)
{
	struct lv0104cs_private *lv0104cs = iio_priv(indio_dev);
	int ret;

	if (chan->type != IIO_LIGHT)
		return -EINVAL;

	mutex_lock(&lv0104cs->lock);

	switch (mask) {
	case IIO_CHAN_INFO_PROCESSED:
		ret = lv0104cs_get_lux(lv0104cs, val, val2);
		if (ret)
			goto err_mutex;
		ret = IIO_VAL_INT_PLUS_MICRO;
		break;

	case IIO_CHAN_INFO_CALIBSCALE:
		*val = lv0104cs_calibscales[lv0104cs->calibscale].val;
		*val2 = lv0104cs_calibscales[lv0104cs->calibscale].val2;
		ret = IIO_VAL_INT_PLUS_MICRO;
		break;

	case IIO_CHAN_INFO_SCALE:
		*val = lv0104cs_scales[lv0104cs->scale].val;
		*val2 = lv0104cs_scales[lv0104cs->scale].val2;
		ret = IIO_VAL_INT_PLUS_MICRO;
		break;

	case IIO_CHAN_INFO_INT_TIME:
		*val = lv0104cs_int_times[lv0104cs->int_time].val;
		*val2 = lv0104cs_int_times[lv0104cs->int_time].val2;
		ret = IIO_VAL_INT_PLUS_MICRO;
		break;

	default:
		ret = -EINVAL;
	}

err_mutex:
	mutex_unlock(&lv0104cs->lock);

	return ret;
}

static int lv0104cs_set_calibscale(struct lv0104cs_private *lv0104cs,
				int val, int val2)
{
	int calibscale = val * 1000000 + val2;
	int floor, ceil, mid;
	int ret, i, index;

	/* round to nearest quantized calibscale (sensitivity) */
	for (i = 0; i < ARRAY_SIZE(lv0104cs_calibscales) - 1; i++) {
		floor = lv0104cs_calibscales[i].val * 1000000
				+ lv0104cs_calibscales[i].val2;
		ceil = lv0104cs_calibscales[i + 1].val * 1000000
				+ lv0104cs_calibscales[i + 1].val2;
		mid = (floor + ceil) / 2;

		/* round down */
		if (calibscale >= floor && calibscale < mid) {
			index = i;
			break;
		}

		/* round up */
		if (calibscale >= mid && calibscale <= ceil) {
			index = i + 1;
			break;
		}
	}

	if (i == ARRAY_SIZE(lv0104cs_calibscales) - 1)
		return -EINVAL;

	mutex_lock(&lv0104cs->lock);

	/* set calibscale (sensitivity) */
	ret = lv0104cs_write_reg(lv0104cs->client,
			lv0104cs_calibscales[index].regval);
	if (ret)
		goto err_mutex;

	lv0104cs->calibscale = index;

err_mutex:
	mutex_unlock(&lv0104cs->lock);

	return ret;
}

static int lv0104cs_set_scale(struct lv0104cs_private *lv0104cs,
				int val, int val2)
{
	int i;

	/* hard matching */
	for (i = 0; i < ARRAY_SIZE(lv0104cs_scales); i++) {
		if (val != lv0104cs_scales[i].val)
			continue;

		if (val2 == lv0104cs_scales[i].val2)
			break;
	}

	if (i == ARRAY_SIZE(lv0104cs_scales))
		return -EINVAL;

	mutex_lock(&lv0104cs->lock);
	lv0104cs->scale = i;
	mutex_unlock(&lv0104cs->lock);

	return 0;
}

static int lv0104cs_set_int_time(struct lv0104cs_private *lv0104cs,
				int val, int val2)
{
	int i;

	/* hard matching */
	for (i = 0; i < ARRAY_SIZE(lv0104cs_int_times); i++) {
		if (val != lv0104cs_int_times[i].val)
			continue;

		if (val2 == lv0104cs_int_times[i].val2)
			break;
	}

	if (i == ARRAY_SIZE(lv0104cs_int_times))
		return -EINVAL;

	mutex_lock(&lv0104cs->lock);
	lv0104cs->int_time = i;
	mutex_unlock(&lv0104cs->lock);

	return 0;
}

static int lv0104cs_write_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int val, int val2, long mask)
{
	struct lv0104cs_private *lv0104cs = iio_priv(indio_dev);

	if (chan->type != IIO_LIGHT)
		return -EINVAL;

	switch (mask) {
	case IIO_CHAN_INFO_CALIBSCALE:
		return lv0104cs_set_calibscale(lv0104cs, val, val2);

	case IIO_CHAN_INFO_SCALE:
		return lv0104cs_set_scale(lv0104cs, val, val2);

	case IIO_CHAN_INFO_INT_TIME:
		return lv0104cs_set_int_time(lv0104cs, val, val2);

	default:
		return -EINVAL;
	}
}

static ssize_t lv0104cs_show_calibscale_avail(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	ssize_t len = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(lv0104cs_calibscales); i++) {
		len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ",
				lv0104cs_calibscales[i].val,
				lv0104cs_calibscales[i].val2);
	}

	buf[len - 1] = '\n';

	return len;
}

static ssize_t lv0104cs_show_scale_avail(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	ssize_t len = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(lv0104cs_scales); i++) {
		len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ",
				lv0104cs_scales[i].val,
				lv0104cs_scales[i].val2);
	}

	buf[len - 1] = '\n';

	return len;
}

static ssize_t lv0104cs_show_int_time_avail(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	ssize_t len = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(lv0104cs_int_times); i++) {
		len += scnprintf(buf + len, PAGE_SIZE - len, "%d.%06d ",
				lv0104cs_int_times[i].val,
				lv0104cs_int_times[i].val2);
	}

	buf[len - 1] = '\n';

	return len;
}

static IIO_DEVICE_ATTR(calibscale_available, 0444,
				lv0104cs_show_calibscale_avail, NULL, 0);
static IIO_DEVICE_ATTR(scale_available, 0444,
				lv0104cs_show_scale_avail, NULL, 0);
static IIO_DEV_ATTR_INT_TIME_AVAIL(lv0104cs_show_int_time_avail);

static struct attribute *lv0104cs_attributes[] = {
	&iio_dev_attr_calibscale_available.dev_attr.attr,
	&iio_dev_attr_scale_available.dev_attr.attr,
	&iio_dev_attr_integration_time_available.dev_attr.attr,
	NULL
};

static const struct attribute_group lv0104cs_attribute_group = {
	.attrs = lv0104cs_attributes,
};

static const struct iio_info lv0104cs_info = {
	.attrs = &lv0104cs_attribute_group,
	.read_raw = &lv0104cs_read_raw,
	.write_raw = &lv0104cs_write_raw,
};

static const struct iio_chan_spec lv0104cs_channels[] = {
	{
		.type = IIO_LIGHT,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
				      BIT(IIO_CHAN_INFO_CALIBSCALE) |
				      BIT(IIO_CHAN_INFO_SCALE) |
				      BIT(IIO_CHAN_INFO_INT_TIME),
	},
};

static int lv0104cs_probe(struct i2c_client *client,
				const struct i2c_device_id *id)
{
	struct iio_dev *indio_dev;
	struct lv0104cs_private *lv0104cs;
	int ret;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*lv0104cs));
	if (!indio_dev)
		return -ENOMEM;

	lv0104cs = iio_priv(indio_dev);

	i2c_set_clientdata(client, lv0104cs);
	lv0104cs->client = client;

	mutex_init(&lv0104cs->lock);

	lv0104cs->calibscale = LV0104CS_CALIBSCALE_UNITY;
	lv0104cs->scale = LV0104CS_SCALE_1X;
	lv0104cs->int_time = LV0104CS_INTEG_200MS;

	ret = lv0104cs_write_reg(lv0104cs->client,
			lv0104cs_calibscales[LV0104CS_CALIBSCALE_UNITY].regval);
	if (ret)
		return ret;

	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->dev.parent = &client->dev;
	indio_dev->channels = lv0104cs_channels;
	indio_dev->num_channels = ARRAY_SIZE(lv0104cs_channels);
	indio_dev->name = client->name;
	indio_dev->info = &lv0104cs_info;

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

static const struct i2c_device_id lv0104cs_id[] = {
	{ "lv0104cs", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, lv0104cs_id);

static struct i2c_driver lv0104cs_i2c_driver = {
	.driver = {
		.name	= "lv0104cs",
	},
	.id_table	= lv0104cs_id,
	.probe		= lv0104cs_probe,
};
module_i2c_driver(lv0104cs_i2c_driver);

MODULE_AUTHOR("Jeff LaBundy <jeff@labundy.com>");
MODULE_DESCRIPTION("LV0104CS Ambient Light Sensor Driver");
MODULE_LICENSE("GPL");