1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2013 Capella Microsystems Inc.
4 * Author: Kevin Tsai <ktsai@capellamicro.com>
5 */
6
7#include <linux/acpi.h>
8#include <linux/delay.h>
9#include <linux/err.h>
10#include <linux/i2c.h>
11#include <linux/mutex.h>
12#include <linux/module.h>
13#include <linux/mod_devicetable.h>
14#include <linux/interrupt.h>
15#include <linux/regulator/consumer.h>
16#include <linux/iio/iio.h>
17#include <linux/iio/sysfs.h>
18#include <linux/iio/events.h>
19#include <linux/init.h>
20
21/* Registers Address */
22#define CM32181_REG_ADDR_CMD		0x00
23#define CM32181_REG_ADDR_WH		0x01
24#define CM32181_REG_ADDR_WL		0x02
25#define CM32181_REG_ADDR_TEST		0x03
26#define CM32181_REG_ADDR_ALS		0x04
27#define CM32181_REG_ADDR_STATUS		0x06
28#define CM32181_REG_ADDR_ID		0x07
29
30/* Number of Configurable Registers */
31#define CM32181_CONF_REG_NUM		4
32
33/* CMD register */
34#define CM32181_CMD_ALS_DISABLE		BIT(0)
35#define CM32181_CMD_ALS_INT_EN		BIT(1)
36#define CM32181_CMD_ALS_THRES_WINDOW	BIT(2)
37
38#define CM32181_CMD_ALS_PERS_SHIFT	4
39#define CM32181_CMD_ALS_PERS_MASK	(0x03 << CM32181_CMD_ALS_PERS_SHIFT)
40#define CM32181_CMD_ALS_PERS_DEFAULT	(0x01 << CM32181_CMD_ALS_PERS_SHIFT)
41
42#define CM32181_CMD_ALS_IT_SHIFT	6
43#define CM32181_CMD_ALS_IT_MASK		(0x0F << CM32181_CMD_ALS_IT_SHIFT)
44#define CM32181_CMD_ALS_IT_DEFAULT	(0x00 << CM32181_CMD_ALS_IT_SHIFT)
45
46#define CM32181_CMD_ALS_SM_SHIFT	11
47#define CM32181_CMD_ALS_SM_MASK		(0x03 << CM32181_CMD_ALS_SM_SHIFT)
48#define CM32181_CMD_ALS_SM_DEFAULT	(0x01 << CM32181_CMD_ALS_SM_SHIFT)
49
50#define CM32181_LUX_PER_BIT		500	/* ALS_SM=01 IT=800ms */
51#define CM32181_LUX_PER_BIT_RESOLUTION	100000
52#define CM32181_LUX_PER_BIT_BASE_IT	800000	/* Based on IT=800ms */
53#define CM32181_CALIBSCALE_DEFAULT	100000
54#define CM32181_CALIBSCALE_RESOLUTION	100000
55
56#define SMBUS_ALERT_RESPONSE_ADDRESS	0x0c
57
58/* CPM0 Index 0: device-id (3218 or 32181), 1: Unknown, 2: init_regs_bitmap */
59#define CPM0_REGS_BITMAP		2
60#define CPM0_HEADER_SIZE		3
61
62/* CPM1 Index 0: lux_per_bit, 1: calibscale, 2: resolution (100000) */
63#define CPM1_LUX_PER_BIT		0
64#define CPM1_CALIBSCALE			1
65#define CPM1_SIZE			3
66
67/* CM3218 Family */
68static const int cm3218_als_it_bits[] = { 0, 1, 2, 3 };
69static const int cm3218_als_it_values[] = { 100000, 200000, 400000, 800000 };
70
71/* CM32181 Family */
72static const int cm32181_als_it_bits[] = { 12, 8, 0, 1, 2, 3 };
73static const int cm32181_als_it_values[] = {
74	25000, 50000, 100000, 200000, 400000, 800000
75};
76
77struct cm32181_chip {
78	struct i2c_client *client;
79	struct device *dev;
80	struct mutex lock;
81	u16 conf_regs[CM32181_CONF_REG_NUM];
82	unsigned long init_regs_bitmap;
83	int calibscale;
84	int lux_per_bit;
85	int lux_per_bit_base_it;
86	int num_als_it;
87	const int *als_it_bits;
88	const int *als_it_values;
89};
90
91static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2);
92
93#ifdef CONFIG_ACPI
94/**
95 * cm32181_acpi_get_cpm() - Get CPM object from ACPI
96 * @dev:	pointer of struct device.
97 * @obj_name:	pointer of ACPI object name.
98 * @values:	pointer of array for return elements.
99 * @count:	maximum size of return array.
100 *
101 * Convert ACPI CPM table to array.
102 *
103 * Return: -ENODEV for fail.  Otherwise is number of elements.
104 */
105static int cm32181_acpi_get_cpm(struct device *dev, char *obj_name,
106				u64 *values, int count)
107{
108	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
109	union acpi_object *cpm, *elem;
110	acpi_handle handle;
111	acpi_status status;
112	int i;
113
114	handle = ACPI_HANDLE(dev);
115	if (!handle)
116		return -ENODEV;
117
118	status = acpi_evaluate_object(handle, obj_name, NULL, &buffer);
119	if (ACPI_FAILURE(status)) {
120		dev_err(dev, "object %s not found\n", obj_name);
121		return -ENODEV;
122	}
123
124	cpm = buffer.pointer;
125	if (cpm->package.count > count)
126		dev_warn(dev, "%s table contains %u values, only using first %d values\n",
127			 obj_name, cpm->package.count, count);
128
129	count = min_t(int, cpm->package.count, count);
130	for (i = 0; i < count; i++) {
131		elem = &(cpm->package.elements[i]);
132		values[i] = elem->integer.value;
133	}
134
135	kfree(buffer.pointer);
136
137	return count;
138}
139
140static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)
141{
142	u64 vals[CPM0_HEADER_SIZE + CM32181_CONF_REG_NUM];
143	struct device *dev = cm32181->dev;
144	int i, count;
145
146	count = cm32181_acpi_get_cpm(dev, "CPM0", vals, ARRAY_SIZE(vals));
147	if (count <= CPM0_HEADER_SIZE)
148		return;
149
150	count -= CPM0_HEADER_SIZE;
151
152	cm32181->init_regs_bitmap = vals[CPM0_REGS_BITMAP];
153	cm32181->init_regs_bitmap &= GENMASK(count - 1, 0);
154	for_each_set_bit(i, &cm32181->init_regs_bitmap, count)
155		cm32181->conf_regs[i] =	vals[CPM0_HEADER_SIZE + i];
156
157	count = cm32181_acpi_get_cpm(dev, "CPM1", vals, ARRAY_SIZE(vals));
158	if (count != CPM1_SIZE)
159		return;
160
161	cm32181->lux_per_bit = vals[CPM1_LUX_PER_BIT];
162
163	/* Check for uncalibrated devices */
164	if (vals[CPM1_CALIBSCALE] == CM32181_CALIBSCALE_DEFAULT)
165		return;
166
167	cm32181->calibscale = vals[CPM1_CALIBSCALE];
168	/* CPM1 lux_per_bit is for the current it value */
169	cm32181_read_als_it(cm32181, &cm32181->lux_per_bit_base_it);
170}
171#else
172static void cm32181_acpi_parse_cpm_tables(struct cm32181_chip *cm32181)
173{
174}
175#endif /* CONFIG_ACPI */
176
177/**
178 * cm32181_reg_init() - Initialize CM32181 registers
179 * @cm32181:	pointer of struct cm32181.
180 *
181 * Initialize CM32181 ambient light sensor register to default values.
182 *
183 * Return: 0 for success; otherwise for error code.
184 */
185static int cm32181_reg_init(struct cm32181_chip *cm32181)
186{
187	struct i2c_client *client = cm32181->client;
188	int i;
189	s32 ret;
190
191	ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ID);
192	if (ret < 0)
193		return ret;
194
195	/* check device ID */
196	switch (ret & 0xFF) {
197	case 0x18: /* CM3218 */
198		cm32181->num_als_it = ARRAY_SIZE(cm3218_als_it_bits);
199		cm32181->als_it_bits = cm3218_als_it_bits;
200		cm32181->als_it_values = cm3218_als_it_values;
201		break;
202	case 0x81: /* CM32181 */
203	case 0x82: /* CM32182, fully compat. with CM32181 */
204		cm32181->num_als_it = ARRAY_SIZE(cm32181_als_it_bits);
205		cm32181->als_it_bits = cm32181_als_it_bits;
206		cm32181->als_it_values = cm32181_als_it_values;
207		break;
208	default:
209		return -ENODEV;
210	}
211
212	/* Default Values */
213	cm32181->conf_regs[CM32181_REG_ADDR_CMD] =
214			CM32181_CMD_ALS_IT_DEFAULT | CM32181_CMD_ALS_SM_DEFAULT;
215	cm32181->init_regs_bitmap = BIT(CM32181_REG_ADDR_CMD);
216	cm32181->calibscale = CM32181_CALIBSCALE_DEFAULT;
217	cm32181->lux_per_bit = CM32181_LUX_PER_BIT;
218	cm32181->lux_per_bit_base_it = CM32181_LUX_PER_BIT_BASE_IT;
219
220	if (ACPI_HANDLE(cm32181->dev))
221		cm32181_acpi_parse_cpm_tables(cm32181);
222
223	/* Initialize registers*/
224	for_each_set_bit(i, &cm32181->init_regs_bitmap, CM32181_CONF_REG_NUM) {
225		ret = i2c_smbus_write_word_data(client, i,
226						cm32181->conf_regs[i]);
227		if (ret < 0)
228			return ret;
229	}
230
231	return 0;
232}
233
234/**
235 *  cm32181_read_als_it() - Get sensor integration time (ms)
236 *  @cm32181:	pointer of struct cm32181
237 *  @val2:	pointer of int to load the als_it value.
238 *
239 *  Report the current integration time in milliseconds.
240 *
241 *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
242 */
243static int cm32181_read_als_it(struct cm32181_chip *cm32181, int *val2)
244{
245	u16 als_it;
246	int i;
247
248	als_it = cm32181->conf_regs[CM32181_REG_ADDR_CMD];
249	als_it &= CM32181_CMD_ALS_IT_MASK;
250	als_it >>= CM32181_CMD_ALS_IT_SHIFT;
251	for (i = 0; i < cm32181->num_als_it; i++) {
252		if (als_it == cm32181->als_it_bits[i]) {
253			*val2 = cm32181->als_it_values[i];
254			return IIO_VAL_INT_PLUS_MICRO;
255		}
256	}
257
258	return -EINVAL;
259}
260
261/**
262 * cm32181_write_als_it() - Write sensor integration time
263 * @cm32181:	pointer of struct cm32181.
264 * @val:	integration time by millisecond.
265 *
266 * Convert integration time (ms) to sensor value.
267 *
268 * Return: i2c_smbus_write_word_data command return value.
269 */
270static int cm32181_write_als_it(struct cm32181_chip *cm32181, int val)
271{
272	struct i2c_client *client = cm32181->client;
273	u16 als_it;
274	int ret, i, n;
275
276	n = cm32181->num_als_it;
277	for (i = 0; i < n; i++)
278		if (val <= cm32181->als_it_values[i])
279			break;
280	if (i >= n)
281		i = n - 1;
282
283	als_it = cm32181->als_it_bits[i];
284	als_it <<= CM32181_CMD_ALS_IT_SHIFT;
285
286	mutex_lock(&cm32181->lock);
287	cm32181->conf_regs[CM32181_REG_ADDR_CMD] &=
288		~CM32181_CMD_ALS_IT_MASK;
289	cm32181->conf_regs[CM32181_REG_ADDR_CMD] |=
290		als_it;
291	ret = i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
292			cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
293	mutex_unlock(&cm32181->lock);
294
295	return ret;
296}
297
298/**
299 * cm32181_get_lux() - report current lux value
300 * @cm32181:	pointer of struct cm32181.
301 *
302 * Convert sensor raw data to lux.  It depends on integration
303 * time and calibscale variable.
304 *
305 * Return: Positive value is lux, otherwise is error code.
306 */
307static int cm32181_get_lux(struct cm32181_chip *cm32181)
308{
309	struct i2c_client *client = cm32181->client;
310	int ret;
311	int als_it;
312	u64 lux;
313
314	ret = cm32181_read_als_it(cm32181, &als_it);
315	if (ret < 0)
316		return -EINVAL;
317
318	lux = cm32181->lux_per_bit;
319	lux *= cm32181->lux_per_bit_base_it;
320	lux = div_u64(lux, als_it);
321
322	ret = i2c_smbus_read_word_data(client, CM32181_REG_ADDR_ALS);
323	if (ret < 0)
324		return ret;
325
326	lux *= ret;
327	lux *= cm32181->calibscale;
328	lux = div_u64(lux, CM32181_CALIBSCALE_RESOLUTION);
329	lux = div_u64(lux, CM32181_LUX_PER_BIT_RESOLUTION);
330
331	if (lux > 0xFFFF)
332		lux = 0xFFFF;
333
334	return lux;
335}
336
337static int cm32181_read_raw(struct iio_dev *indio_dev,
338			    struct iio_chan_spec const *chan,
339			    int *val, int *val2, long mask)
340{
341	struct cm32181_chip *cm32181 = iio_priv(indio_dev);
342	int ret;
343
344	switch (mask) {
345	case IIO_CHAN_INFO_PROCESSED:
346		ret = cm32181_get_lux(cm32181);
347		if (ret < 0)
348			return ret;
349		*val = ret;
350		return IIO_VAL_INT;
351	case IIO_CHAN_INFO_CALIBSCALE:
352		*val = cm32181->calibscale;
353		return IIO_VAL_INT;
354	case IIO_CHAN_INFO_INT_TIME:
355		*val = 0;
356		ret = cm32181_read_als_it(cm32181, val2);
357		return ret;
358	}
359
360	return -EINVAL;
361}
362
363static int cm32181_write_raw(struct iio_dev *indio_dev,
364			     struct iio_chan_spec const *chan,
365			     int val, int val2, long mask)
366{
367	struct cm32181_chip *cm32181 = iio_priv(indio_dev);
368	int ret;
369
370	switch (mask) {
371	case IIO_CHAN_INFO_CALIBSCALE:
372		cm32181->calibscale = val;
373		return val;
374	case IIO_CHAN_INFO_INT_TIME:
375		ret = cm32181_write_als_it(cm32181, val2);
376		return ret;
377	}
378
379	return -EINVAL;
380}
381
382/**
383 * cm32181_get_it_available() - Get available ALS IT value
384 * @dev:	pointer of struct device.
385 * @attr:	pointer of struct device_attribute.
386 * @buf:	pointer of return string buffer.
387 *
388 * Display the available integration time values by millisecond.
389 *
390 * Return: string length.
391 */
392static ssize_t cm32181_get_it_available(struct device *dev,
393			struct device_attribute *attr, char *buf)
394{
395	struct cm32181_chip *cm32181 = iio_priv(dev_to_iio_dev(dev));
396	int i, n, len;
397
398	n = cm32181->num_als_it;
399	for (i = 0, len = 0; i < n; i++)
400		len += sprintf(buf + len, "0.%06u ", cm32181->als_it_values[i]);
401	return len + sprintf(buf + len, "\n");
402}
403
404static const struct iio_chan_spec cm32181_channels[] = {
405	{
406		.type = IIO_LIGHT,
407		.info_mask_separate =
408			BIT(IIO_CHAN_INFO_PROCESSED) |
409			BIT(IIO_CHAN_INFO_CALIBSCALE) |
410			BIT(IIO_CHAN_INFO_INT_TIME),
411	}
412};
413
414static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
415			S_IRUGO, cm32181_get_it_available, NULL, 0);
416
417static struct attribute *cm32181_attributes[] = {
418	&iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
419	NULL,
420};
421
422static const struct attribute_group cm32181_attribute_group = {
423	.attrs = cm32181_attributes
424};
425
426static const struct iio_info cm32181_info = {
427	.read_raw		= &cm32181_read_raw,
428	.write_raw		= &cm32181_write_raw,
429	.attrs			= &cm32181_attribute_group,
430};
431
432static void cm32181_unregister_dummy_client(void *data)
433{
434	struct i2c_client *client = data;
435
436	/* Unregister the dummy client */
437	i2c_unregister_device(client);
438}
439
440static int cm32181_probe(struct i2c_client *client)
441{
442	struct device *dev = &client->dev;
443	struct cm32181_chip *cm32181;
444	struct iio_dev *indio_dev;
445	int ret;
446
447	indio_dev = devm_iio_device_alloc(dev, sizeof(*cm32181));
448	if (!indio_dev)
449		return -ENOMEM;
450
451	i2c_set_clientdata(client, indio_dev);
452
453	/*
454	 * Some ACPI systems list 2 I2C resources for the CM3218 sensor, the
455	 * SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address.
456	 * Detect this and take the following step to deal with it:
457	 * 1. When a SMBus Alert capable sensor has an Alert asserted, it will
458	 *    not respond on its actual I2C address. Read a byte from the ARA
459	 *    to clear any pending Alerts.
460	 * 2. Create a "dummy" client for the actual I2C address and
461	 *    use that client to communicate with the sensor.
462	 */
463	if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) {
464		struct i2c_board_info board_info = { .type = "dummy" };
465
466		i2c_smbus_read_byte(client);
467
468		client = i2c_acpi_new_device(dev, 1, &board_info);
469		if (IS_ERR(client))
470			return PTR_ERR(client);
471
472		ret = devm_add_action_or_reset(dev, cm32181_unregister_dummy_client, client);
473		if (ret)
474			return ret;
475	}
476
477	cm32181 = iio_priv(indio_dev);
478	cm32181->client = client;
479	cm32181->dev = dev;
480
481	mutex_init(&cm32181->lock);
482	indio_dev->channels = cm32181_channels;
483	indio_dev->num_channels = ARRAY_SIZE(cm32181_channels);
484	indio_dev->info = &cm32181_info;
485	indio_dev->name = dev_name(dev);
486	indio_dev->modes = INDIO_DIRECT_MODE;
487
488	ret = cm32181_reg_init(cm32181);
489	if (ret) {
490		dev_err(dev, "%s: register init failed\n", __func__);
491		return ret;
492	}
493
494	ret = devm_iio_device_register(dev, indio_dev);
495	if (ret) {
496		dev_err(dev, "%s: regist device failed\n", __func__);
497		return ret;
498	}
499
500	return 0;
501}
502
503static int cm32181_suspend(struct device *dev)
504{
505	struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
506	struct i2c_client *client = cm32181->client;
507
508	return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
509					 CM32181_CMD_ALS_DISABLE);
510}
511
512static int cm32181_resume(struct device *dev)
513{
514	struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev));
515	struct i2c_client *client = cm32181->client;
516
517	return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD,
518					 cm32181->conf_regs[CM32181_REG_ADDR_CMD]);
519}
520
521static DEFINE_SIMPLE_DEV_PM_OPS(cm32181_pm_ops, cm32181_suspend, cm32181_resume);
522
523static const struct of_device_id cm32181_of_match[] = {
524	{ .compatible = "capella,cm3218" },
525	{ .compatible = "capella,cm32181" },
526	{ }
527};
528MODULE_DEVICE_TABLE(of, cm32181_of_match);
529
530#ifdef CONFIG_ACPI
531static const struct acpi_device_id cm32181_acpi_match[] = {
532	{ "CPLM3218", 0 },
533	{ }
534};
535MODULE_DEVICE_TABLE(acpi, cm32181_acpi_match);
536#endif
537
538static struct i2c_driver cm32181_driver = {
539	.driver = {
540		.name	= "cm32181",
541		.acpi_match_table = ACPI_PTR(cm32181_acpi_match),
542		.of_match_table = cm32181_of_match,
543		.pm = pm_sleep_ptr(&cm32181_pm_ops),
544	},
545	.probe		= cm32181_probe,
546};
547
548module_i2c_driver(cm32181_driver);
549
550MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
551MODULE_DESCRIPTION("CM32181 ambient light sensor driver");
552MODULE_LICENSE("GPL");
553