summaryrefslogtreecommitdiff
path: root/drivers/iio/light/cm32181.c
blob: 97649944f1df65651076f83b9db169ad87a5253e (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2013 Capella Microsystems Inc.
 * Author: Kevin Tsai <ktsai@capellamicro.com>
 */

#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/interrupt.h>
#include <linux/regulator/consumer.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/events.h>
#include <linux/init.h>

/* Registers Address */
#define CM32181_REG_ADDR_CMD		0x00
#define CM32181_REG_ADDR_WH		0x01
#define CM32181_REG_ADDR_WL		0x02
#define CM32181_REG_ADDR_TEST		0x03
#define CM32181_REG_ADDR_ALS		0x04
#define CM32181_REG_ADDR_STATUS		0x06
#define CM32181_REG_ADDR_ID		0x07

/* Number of Configurable Registers */
#define CM32181_CONF_REG_NUM		4

/* CMD register */
#define CM32181_CMD_ALS_DISABLE		BIT(0)
#define CM32181_CMD_ALS_INT_EN		BIT(1)
#define CM32181_CMD_ALS_THRES_WINDOW	BIT(2)

#define CM32181_CMD_ALS_PERS_SHIFT	4
#define CM32181_CMD_ALS_PERS_MASK	(0x03 << CM32181_CMD_ALS_PERS_SHIFT)
#define CM32181_CMD_ALS_PERS_DEFAULT	(0x01 << CM32181_CMD_ALS_PERS_SHIFT)

#define CM32181_CMD_ALS_IT_SHIFT	6
#define CM32181_CMD_ALS_IT_MASK		(0x0F << CM32181_CMD_ALS_IT_SHIFT)
#define CM32181_CMD_ALS_IT_DEFAULT	(0x00 << CM32181_CMD_ALS_IT_SHIFT)

#define CM32181_CMD_ALS_SM_SHIFT	11
#define CM32181_CMD_ALS_SM_MASK		(0x03 << CM32181_CMD_ALS_SM_SHIFT)
#define CM32181_CMD_ALS_SM_DEFAULT	(0x01 << CM32181_CMD_ALS_SM_SHIFT)

#define CM32181_LUX_PER_BIT		500	/* ALS_SM=01 IT=800ms */
#define CM32181_LUX_PER_BIT_RESOLUTION	100000
#define CM32181_LUX_PER_BIT_BASE_IT	800000	/* Based on IT=800ms */
#define CM32181_CALIBSCALE_DEFAULT	100000
#define CM32181_CALIBSCALE_RESOLUTION	100000

#define SMBUS_ALERT_RESPONSE_ADDRESS	0x0c

/* CPM0 Index 0: device-id (3218 or 32181), 1: Unknown, 2: init_regs_bitmap */
#define CPM0_REGS_BITMAP		2
#define CPM0_HEADER_SIZE		3

/* CPM1 Index 0: lux_per_bit, 1: calibscale, 2: resolution (100000) */
#define CPM1_LUX_PER_BIT		0
#define CPM1_CALIBSCALE			1
#define CPM1_SIZE			3

/* CM3218 Family */
static const int cm3218_als_it_bits[] = { 0, 1, 2, 3 };
static const int cm3218_als_it_values[] = { 100000, 200000, 400000, 800000 };

/* CM32181 Family */
static const int cm32181_als_it_bits[] = { 12, 8, 0, 1, 2, 3 };
static const int cm32181_als_it_values[] = {
	25000, 50000, 100000, 200000, 400000, 800000
};

struct cm32181_chip {
	struct i2c_client *client;
	struct device *dev;
	struct mutex lock;
	u16 conf_regs[CM32181_CONF_REG_NUM];
	unsigned long init_regs_bitmap;
	int calibscale;
	int lux_per_bit;
	int lux_per_bit_base_it;
	int num_als_it;
	const int *als_it_bits;
	const int *als_it_values;
};

static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2);

#ifdef CONFIG_ACPI
/**
 * cm32181_acpi_get_cpm() - Get CPM object from ACPI
 * @dev:	pointer of struct device.
 * @obj_name:	pointer of ACPI object name.
 * @values:	pointer of array for return elements.
 * @count:	maximum size of return array.
 *
 * Convert ACPI CPM table to array.
 *
 * Return: -ENODEV for fail.  Otherwise is number of elements.
 */
static int cm32181_acpi_get_cpm(struct device *dev, char *obj_name,
				u64 *values, int count)
{
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *cpm, *elem;
	acpi_handle handle;
	acpi_status status;
	int i;

	handle = ACPI_HANDLE(dev);
	if (!handle)
		return -ENODEV;

	status = acpi_evaluate_object(handle, obj_name, NULL, &buffer);
	if (ACPI_FAILURE(status)) {
		dev_err(dev, "object %s not found\n", obj_name);
		return -ENODEV;
	}

	cpm = buffer.pointer;
	if (cpm->package.count > count)
		dev_warn(dev, "%s table contains %u values, only using first %d values\n",
			 obj_name, cpm->package.count, count);

	count = min_t(int, cpm->package.count, count);
	for (i = 0; i < count; i++) {
		elem = &(cpm->package.elements[i]);
		values[i] = elem->integer.value;
	}

	kfree(buffer.pointer);

	return count;
}

static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)
{
	u64 vals[CPM0_HEADER_SIZE + CM32181_CONF_REG_NUM];
	struct device *dev = cm32181->dev;
	int i, count;

	count = cm32181_acpi_get_cpm(dev, "CPM0", vals, ARRAY_SIZE(vals));
	if (count <= CPM0_HEADER_SIZE)
		return;

	count -= CPM0_HEADER_SIZE;

	cm32181->init_regs_bitmap = vals[CPM0_REGS_BITMAP];
	cm32181->init_regs_bitmap &= GENMASK(count - 1, 0);
	for_each_set_bit(i, &cm32181->init_regs_bitmap, count)
		cm32181->conf_regs[i] =	vals[CPM0_HEADER_SIZE + i];

	count = cm32181_acpi_get_cpm(dev, "CPM1", vals, ARRAY_SIZE(vals));
	if (count != CPM1_SIZE)
		return;

	cm32181->lux_per_bit = vals[CPM1_LUX_PER_BIT];

	/* Check for uncalibrated devices */
	if (vals[CPM1_CALIBSCALE] == CM32181_CALIBSCALE_DEFAULT)
		return;

	cm32181->calibscale = vals[CPM1_CALIBSCALE];
	/* CPM1 lux_per_bit is for the current it value */
	cm32181_read_als_it(cm32181, &cm32181->lux_per_bit_base_it);
}
#else
static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)
{
}
#endif /* CONFIG_ACPI */

/**
 * cm32181_reg_init() - Initialize CM32181 registers
 * @cm32181:	pointer of struct cm32181.
 *
 * Initialize CM32181 ambient light sensor register to default values.
 *
 * Return: 0 for success; otherwise for error code.
 */
static int cm32181_reg_init(struct cm32181_chip *cm32181)
{
	struct i2c_client *client = cm32181->client;
	int i;
	s32 ret;

	ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ID);
	if (ret < 0)
		return ret;

	/* check device ID */
	switch (ret & 0xFF) {
	case 0x18: /* CM3218 */
		cm32181->num_als_it = ARRAY_SIZE(cm3218_als_it_bits);
		cm32181->als_it_bits = cm3218_als_it_bits;
		cm32181->als_it_values = cm3218_als_it_values;
		break;
	case 0x81: /* CM32181 */
	case 0x82: /* CM32182, fully compat. with CM32181 */
		cm32181->num_als_it = ARRAY_SIZE(cm32181_als_it_bits);
		cm32181->als_it_bits = cm32181_als_it_bits;
		cm32181->als_it_values = cm32181_als_it_values;
		break;
	default:
		return -ENODEV;
	}

	/* Default Values */
	cm32181->conf_regs[CM32181_REG_ADDR_CMD] =
			CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT;
	cm32181->init_regs_bitmap = BIT(CM32181_REG_ADDR_CMD);
	cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT;
	cm32181->lux_per_bit = CM32181_LUX_PER_BIT;
	cm32181->lux_per_bit_base_it = CM32181_LUX_PER_BIT_BASE_IT;

	if (ACPI_HANDLE(cm32181->dev))
		cm32181_acpi_parse_cpm_tables(cm32181);

	/* Initialize registers*/
	for_each_set_bit(i, &cm32181->init_regs_bitmap, CM32181_CONF_REG_NUM) {
		ret = i2c_smbus_write_word_data(client, i,
						cm32181->conf_regs[i]);
		if (ret < 0)
			return ret;
	}

	return 0;
}

/**
 *  cm32181_read_als_it() - Get sensor integration time (ms)
 *  @cm32181:	pointer of struct cm32181
 *  @val2:	pointer of int to load the als_it value.
 *
 *  Report the current integration time in milliseconds.
 *
 *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
 */
static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2)
{
	u16 als_it;
	int i;

	als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD];
	als_it &= CM32181_CMD_ALS_IT_MASK;
	als_it >>= CM32181_CMD_ALS_IT_SHIFT;
	for (i = 0; i < cm32181->num_als_it; i++) {
		if (als_it == cm32181->als_it_bits[i]) {
			*val2 = cm32181->als_it_values[i];
			return IIO_VAL_INT_PLUS_MICRO;
		}
	}

	return -EINVAL;
}

/**
 * cm32181_write_als_it() - Write sensor integration time
 * @cm32181:	pointer of struct cm32181.
 * @val:	integration time by millisecond.
 *
 * Convert integration time (ms) to sensor value.
 *
 * Return: i2c_smbus_write_word_data command return value.
 */
static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val)
{
	struct i2c_client *client = cm32181->client;
	u16 als_it;
	int ret, i, n;

	n = cm32181->num_als_it;
	for (i = 0; i < n; i++)
		if (val <= cm32181->als_it_values[i])
			break;
	if (i >= n)
		i = n - 1;

	als_it = cm32181->als_it_bits[i];
	als_it <<= CM32181_CMD_ALS_IT_SHIFT;

	mutex_lock(&cm32181->lock);
	cm32181->conf_regs[CM32181_REG_ADDR_CMD] &=
		~CM32181_CMD_ALS_IT_MASK;
	cm32181->conf_regs[CM32181_REG_ADDR_CMD] |=
		als_it;
	ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
			cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
	mutex_unlock(&cm32181->lock);

	return ret;
}

/**
 * cm32181_get_lux() - report current lux value
 * @cm32181:	pointer of struct cm32181.
 *
 * Convert sensor raw data to lux.  It depends on integration
 * time and calibscale variable.
 *
 * Return: Positive value is lux, otherwise is error code.
 */
static int cm32181_get_lux(struct cm32181_chip *cm32181)
{
	struct i2c_client *client = cm32181->client;
	int ret;
	int als_it;
	u64 lux;

	ret = cm32181_read_als_it(cm32181, &als_it);
	if (ret < 0)
		return -EINVAL;

	lux = cm32181->lux_per_bit;
	lux *= cm32181->lux_per_bit_base_it;
	lux = div_u64(lux, als_it);

	ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
	if (ret < 0)
		return ret;

	lux *= ret;
	lux *= cm32181->calibscale;
	lux = div_u64(lux, CM32181_CALIBSCALE_RESOLUTION);
	lux = div_u64(lux, CM32181_LUX_PER_BIT_RESOLUTION);

	if (lux > 0xFFFF)
		lux = 0xFFFF;

	return lux;
}

static int cm32181_read_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int *val, int *val2, long mask)
{
	struct cm32181_chip *cm32181 = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_PROCESSED:
		ret = cm32181_get_lux(cm32181);
		if (ret < 0)
			return ret;
		*val = ret;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_CALIBSCALE:
		*val = cm32181->calibscale;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_INT_TIME:
		*val = 0;
		ret = cm32181_read_als_it(cm32181, val2);
		return ret;
	}

	return -EINVAL;
}

static int cm32181_write_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int val, int val2, long mask)
{
	struct cm32181_chip *cm32181 = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_CALIBSCALE:
		cm32181->calibscale = val;
		return val;
	case IIO_CHAN_INFO_INT_TIME:
		ret = cm32181_write_als_it(cm32181, val2);
		return ret;
	}

	return -EINVAL;
}

/**
 * cm32181_get_it_available() - Get available ALS IT value
 * @dev:	pointer of struct device.
 * @attr:	pointer of struct device_attribute.
 * @buf:	pointer of return string buffer.
 *
 * Display the available integration time values by millisecond.
 *
 * Return: string length.
 */
static ssize_t cm32181_get_it_available(struct device *dev,
			struct device_attribute *attr, char *buf)
{
	struct cm32181_chip *cm32181 = iio_priv(dev_to_iio_dev(dev));
	int i, n, len;

	n = cm32181->num_als_it;
	for (i = 0, len = 0; i < n; i++)
		len += sprintf(buf + len, "0.%06u ", cm32181->als_it_values[i]);
	return len + sprintf(buf + len, "\n");
}

static const struct iio_chan_spec cm32181_channels[] = {
	{
		.type = IIO_LIGHT,
		.info_mask_separate =
			BIT(IIO_CHAN_INFO_PROCESSED) |
			BIT(IIO_CHAN_INFO_CALIBSCALE) |
			BIT(IIO_CHAN_INFO_INT_TIME),
	}
};

static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
			S_IRUGO, cm32181_get_it_available, NULL, 0);

static struct attribute *cm32181_attributes[] = {
	&iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
	NULL,
};

static const struct attribute_group cm32181_attribute_group = {
	.attrs = cm32181_attributes
};

static const struct iio_info cm32181_info = {
	.read_raw		= &cm32181_read_raw,
	.write_raw		= &cm32181_write_raw,
	.attrs			= &cm32181_attribute_group,
};

static int cm32181_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct cm32181_chip *cm32181;
	struct iio_dev *indio_dev;
	int ret;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*cm32181));
	if (!indio_dev)
		return -ENOMEM;

	/*
	 * Some ACPI systems list 2 I2C resources for the CM3218 sensor, the
	 * SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address.
	 * Detect this and take the following step to deal with it:
	 * 1. When a SMBus Alert capable sensor has an Alert asserted, it will
	 *    not respond on its actual I2C address. Read a byte from the ARA
	 *    to clear any pending Alerts.
	 * 2. Create a "dummy" client for the actual I2C address and
	 *    use that client to communicate with the sensor.
	 */
	if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) {
		struct i2c_board_info board_info = { .type = "dummy" };

		i2c_smbus_read_byte(client);

		client = i2c_acpi_new_device(dev, 1, &board_info);
		if (IS_ERR(client))
			return PTR_ERR(client);
	}

	cm32181 = iio_priv(indio_dev);
	cm32181->client = client;
	cm32181->dev = dev;

	mutex_init(&cm32181->lock);
	indio_dev->channels = cm32181_channels;
	indio_dev->num_channels = ARRAY_SIZE(cm32181_channels);
	indio_dev->info = &cm32181_info;
	indio_dev->name = dev_name(dev);
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = cm32181_reg_init(cm32181);
	if (ret) {
		dev_err(dev, "%s: register init failed\n", __func__);
		return ret;
	}

	ret = devm_iio_device_register(dev, indio_dev);
	if (ret) {
		dev_err(dev, "%s: regist device failed\n", __func__);
		return ret;
	}

	return 0;
}

static const struct of_device_id cm32181_of_match[] = {
	{ .compatible = "capella,cm3218" },
	{ .compatible = "capella,cm32181" },
	{ }
};
MODULE_DEVICE_TABLE(of, cm32181_of_match);

#ifdef CONFIG_ACPI
static const struct acpi_device_id cm32181_acpi_match[] = {
	{ "CPLM3218", 0 },
	{ }
};
MODULE_DEVICE_TABLE(acpi, cm32181_acpi_match);
#endif

static struct i2c_driver cm32181_driver = {
	.driver = {
		.name	= "cm32181",
		.acpi_match_table = ACPI_PTR(cm32181_acpi_match),
		.of_match_table = cm32181_of_match,
	},
	.probe_new	= cm32181_probe,
};

module_i2c_driver(cm32181_driver);

MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
MODULE_DESCRIPTION("CM32181 ambient light sensor driver");
MODULE_LICENSE("GPL");