1/*
2 * apds9300.c - IIO driver for Avago APDS9300 ambient light sensor
3 *
4 * Copyright 2013 Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
5 *
6 * This file is subject to the terms and conditions of version 2 of
7 * the GNU General Public License.  See the file COPYING in the main
8 * directory of this archive for more details.
9 */
10
11#include <linux/module.h>
12#include <linux/slab.h>
13#include <linux/pm.h>
14#include <linux/i2c.h>
15#include <linux/err.h>
16#include <linux/mutex.h>
17#include <linux/interrupt.h>
18#include <linux/iio/iio.h>
19#include <linux/iio/sysfs.h>
20#include <linux/iio/events.h>
21
22#define APDS9300_DRV_NAME "apds9300"
23#define APDS9300_IRQ_NAME "apds9300_event"
24
25/* Command register bits */
26#define APDS9300_CMD	BIT(7) /* Select command register. Must write as 1 */
27#define APDS9300_WORD	BIT(5) /* I2C write/read: if 1 word, if 0 byte */
28#define APDS9300_CLEAR	BIT(6) /* Interrupt clear. Clears pending interrupt */
29
30/* Register set */
31#define APDS9300_CONTROL	0x00 /* Control of basic functions */
32#define APDS9300_THRESHLOWLOW	0x02 /* Low byte of low interrupt threshold */
33#define APDS9300_THRESHHIGHLOW	0x04 /* Low byte of high interrupt threshold */
34#define APDS9300_INTERRUPT	0x06 /* Interrupt control */
35#define APDS9300_DATA0LOW	0x0c /* Low byte of ADC channel 0 */
36#define APDS9300_DATA1LOW	0x0e /* Low byte of ADC channel 1 */
37
38/* Power on/off value for APDS9300_CONTROL register */
39#define APDS9300_POWER_ON	0x03
40#define APDS9300_POWER_OFF	0x00
41
42/* Interrupts */
43#define APDS9300_INTR_ENABLE	0x10
44/* Interrupt Persist Function: Any value outside of threshold range */
45#define APDS9300_THRESH_INTR	0x01
46
47#define APDS9300_THRESH_MAX	0xffff /* Max threshold value */
48
49struct apds9300_data {
50	struct i2c_client *client;
51	struct mutex mutex;
52	int power_state;
53	int thresh_low;
54	int thresh_hi;
55	int intr_en;
56};
57
58/* Lux calculation */
59
60/* Calculated values 1000 * (CH1/CH0)^1.4 for CH1/CH0 from 0 to 0.52 */
61static const u16 apds9300_lux_ratio[] = {
62	0, 2, 4, 7, 11, 15, 19, 24, 29, 34, 40, 45, 51, 57, 64, 70, 77, 84, 91,
63	98, 105, 112, 120, 128, 136, 144, 152, 160, 168, 177, 185, 194, 203,
64	212, 221, 230, 239, 249, 258, 268, 277, 287, 297, 307, 317, 327, 337,
65	347, 358, 368, 379, 390, 400,
66};
67
68static unsigned long apds9300_calculate_lux(u16 ch0, u16 ch1)
69{
70	unsigned long lux, tmp;
71
72	/* avoid division by zero */
73	if (ch0 == 0)
74		return 0;
75
76	tmp = DIV_ROUND_UP(ch1 * 100, ch0);
77	if (tmp <= 52) {
78		lux = 3150 * ch0 - (unsigned long)DIV_ROUND_UP_ULL(ch0
79				* apds9300_lux_ratio[tmp] * 5930ull, 1000);
80	} else if (tmp <= 65) {
81		lux = 2290 * ch0 - 2910 * ch1;
82	} else if (tmp <= 80) {
83		lux = 1570 * ch0 - 1800 * ch1;
84	} else if (tmp <= 130) {
85		lux = 338 * ch0 - 260 * ch1;
86	} else {
87		lux = 0;
88	}
89
90	return lux / 100000;
91}
92
93static int apds9300_get_adc_val(struct apds9300_data *data, int adc_number)
94{
95	int ret;
96	u8 flags = APDS9300_CMD | APDS9300_WORD;
97
98	if (!data->power_state)
99		return -EBUSY;
100
101	/* Select ADC0 or ADC1 data register */
102	flags |= adc_number ? APDS9300_DATA1LOW : APDS9300_DATA0LOW;
103
104	ret = i2c_smbus_read_word_data(data->client, flags);
105	if (ret < 0)
106		dev_err(&data->client->dev,
107			"failed to read ADC%d value\n", adc_number);
108
109	return ret;
110}
111
112static int apds9300_set_thresh_low(struct apds9300_data *data, int value)
113{
114	int ret;
115
116	if (!data->power_state)
117		return -EBUSY;
118
119	if (value > APDS9300_THRESH_MAX)
120		return -EINVAL;
121
122	ret = i2c_smbus_write_word_data(data->client, APDS9300_THRESHLOWLOW
123			| APDS9300_CMD | APDS9300_WORD, value);
124	if (ret) {
125		dev_err(&data->client->dev, "failed to set thresh_low\n");
126		return ret;
127	}
128	data->thresh_low = value;
129
130	return 0;
131}
132
133static int apds9300_set_thresh_hi(struct apds9300_data *data, int value)
134{
135	int ret;
136
137	if (!data->power_state)
138		return -EBUSY;
139
140	if (value > APDS9300_THRESH_MAX)
141		return -EINVAL;
142
143	ret = i2c_smbus_write_word_data(data->client, APDS9300_THRESHHIGHLOW
144			| APDS9300_CMD | APDS9300_WORD, value);
145	if (ret) {
146		dev_err(&data->client->dev, "failed to set thresh_hi\n");
147		return ret;
148	}
149	data->thresh_hi = value;
150
151	return 0;
152}
153
154static int apds9300_set_intr_state(struct apds9300_data *data, int state)
155{
156	int ret;
157	u8 cmd;
158
159	if (!data->power_state)
160		return -EBUSY;
161
162	cmd = state ? APDS9300_INTR_ENABLE | APDS9300_THRESH_INTR : 0x00;
163	ret = i2c_smbus_write_byte_data(data->client,
164			APDS9300_INTERRUPT | APDS9300_CMD, cmd);
165	if (ret) {
166		dev_err(&data->client->dev,
167			"failed to set interrupt state %d\n", state);
168		return ret;
169	}
170	data->intr_en = state;
171
172	return 0;
173}
174
175static int apds9300_set_power_state(struct apds9300_data *data, int state)
176{
177	int ret;
178	u8 cmd;
179
180	cmd = state ? APDS9300_POWER_ON : APDS9300_POWER_OFF;
181	ret = i2c_smbus_write_byte_data(data->client,
182			APDS9300_CONTROL | APDS9300_CMD, cmd);
183	if (ret) {
184		dev_err(&data->client->dev,
185			"failed to set power state %d\n", state);
186		return ret;
187	}
188	data->power_state = state;
189
190	return 0;
191}
192
193static void apds9300_clear_intr(struct apds9300_data *data)
194{
195	int ret;
196
197	ret = i2c_smbus_write_byte(data->client, APDS9300_CLEAR | APDS9300_CMD);
198	if (ret < 0)
199		dev_err(&data->client->dev, "failed to clear interrupt\n");
200}
201
202static int apds9300_chip_init(struct apds9300_data *data)
203{
204	int ret;
205
206	/* Need to set power off to ensure that the chip is off */
207	ret = apds9300_set_power_state(data, 0);
208	if (ret < 0)
209		goto err;
210	/*
211	 * Probe the chip. To do so we try to power up the device and then to
212	 * read back the 0x03 code
213	 */
214	ret = apds9300_set_power_state(data, 1);
215	if (ret < 0)
216		goto err;
217	ret = i2c_smbus_read_byte_data(data->client,
218			APDS9300_CONTROL | APDS9300_CMD);
219	if (ret != APDS9300_POWER_ON) {
220		ret = -ENODEV;
221		goto err;
222	}
223	/*
224	 * Disable interrupt to ensure thai it is doesn't enable
225	 * i.e. after device soft reset
226	 */
227	ret = apds9300_set_intr_state(data, 0);
228	if (ret < 0)
229		goto err;
230
231	return 0;
232
233err:
234	dev_err(&data->client->dev, "failed to init the chip\n");
235	return ret;
236}
237
238static int apds9300_read_raw(struct iio_dev *indio_dev,
239		struct iio_chan_spec const *chan, int *val, int *val2,
240		long mask)
241{
242	int ch0, ch1, ret = -EINVAL;
243	struct apds9300_data *data = iio_priv(indio_dev);
244
245	mutex_lock(&data->mutex);
246	switch (chan->type) {
247	case IIO_LIGHT:
248		ch0 = apds9300_get_adc_val(data, 0);
249		if (ch0 < 0) {
250			ret = ch0;
251			break;
252		}
253		ch1 = apds9300_get_adc_val(data, 1);
254		if (ch1 < 0) {
255			ret = ch1;
256			break;
257		}
258		*val = apds9300_calculate_lux(ch0, ch1);
259		ret = IIO_VAL_INT;
260		break;
261	case IIO_INTENSITY:
262		ret = apds9300_get_adc_val(data, chan->channel);
263		if (ret < 0)
264			break;
265		*val = ret;
266		ret = IIO_VAL_INT;
267		break;
268	default:
269		break;
270	}
271	mutex_unlock(&data->mutex);
272
273	return ret;
274}
275
276static int apds9300_read_thresh(struct iio_dev *indio_dev,
277		const struct iio_chan_spec *chan, enum iio_event_type type,
278		enum iio_event_direction dir, enum iio_event_info info,
279		int *val, int *val2)
280{
281	struct apds9300_data *data = iio_priv(indio_dev);
282
283	switch (dir) {
284	case IIO_EV_DIR_RISING:
285		*val = data->thresh_hi;
286		break;
287	case IIO_EV_DIR_FALLING:
288		*val = data->thresh_low;
289		break;
290	default:
291		return -EINVAL;
292	}
293
294	return IIO_VAL_INT;
295}
296
297static int apds9300_write_thresh(struct iio_dev *indio_dev,
298		const struct iio_chan_spec *chan, enum iio_event_type type,
299		enum iio_event_direction dir, enum iio_event_info info, int val,
300		int val2)
301{
302	struct apds9300_data *data = iio_priv(indio_dev);
303	int ret;
304
305	mutex_lock(&data->mutex);
306	if (dir == IIO_EV_DIR_RISING)
307		ret = apds9300_set_thresh_hi(data, val);
308	else
309		ret = apds9300_set_thresh_low(data, val);
310	mutex_unlock(&data->mutex);
311
312	return ret;
313}
314
315static int apds9300_read_interrupt_config(struct iio_dev *indio_dev,
316		const struct iio_chan_spec *chan,
317		enum iio_event_type type,
318		enum iio_event_direction dir)
319{
320	struct apds9300_data *data = iio_priv(indio_dev);
321
322	return data->intr_en;
323}
324
325static int apds9300_write_interrupt_config(struct iio_dev *indio_dev,
326		const struct iio_chan_spec *chan, enum iio_event_type type,
327		enum iio_event_direction dir, int state)
328{
329	struct apds9300_data *data = iio_priv(indio_dev);
330	int ret;
331
332	mutex_lock(&data->mutex);
333	ret = apds9300_set_intr_state(data, state);
334	mutex_unlock(&data->mutex);
335
336	return ret;
337}
338
339static const struct iio_info apds9300_info_no_irq = {
340	.driver_module	= THIS_MODULE,
341	.read_raw	= apds9300_read_raw,
342};
343
344static const struct iio_info apds9300_info = {
345	.driver_module		= THIS_MODULE,
346	.read_raw		= apds9300_read_raw,
347	.read_event_value	= apds9300_read_thresh,
348	.write_event_value	= apds9300_write_thresh,
349	.read_event_config	= apds9300_read_interrupt_config,
350	.write_event_config	= apds9300_write_interrupt_config,
351};
352
353static const struct iio_event_spec apds9300_event_spec[] = {
354	{
355		.type = IIO_EV_TYPE_THRESH,
356		.dir = IIO_EV_DIR_RISING,
357		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
358			BIT(IIO_EV_INFO_ENABLE),
359	}, {
360		.type = IIO_EV_TYPE_THRESH,
361		.dir = IIO_EV_DIR_FALLING,
362		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
363			BIT(IIO_EV_INFO_ENABLE),
364	},
365};
366
367static const struct iio_chan_spec apds9300_channels[] = {
368	{
369		.type = IIO_LIGHT,
370		.channel = 0,
371		.indexed = true,
372		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
373	}, {
374		.type = IIO_INTENSITY,
375		.channel = 0,
376		.channel2 = IIO_MOD_LIGHT_BOTH,
377		.indexed = true,
378		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
379		.event_spec = apds9300_event_spec,
380		.num_event_specs = ARRAY_SIZE(apds9300_event_spec),
381	}, {
382		.type = IIO_INTENSITY,
383		.channel = 1,
384		.channel2 = IIO_MOD_LIGHT_IR,
385		.indexed = true,
386		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
387	},
388};
389
390static irqreturn_t apds9300_interrupt_handler(int irq, void *private)
391{
392	struct iio_dev *dev_info = private;
393	struct apds9300_data *data = iio_priv(dev_info);
394
395	iio_push_event(dev_info,
396		       IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
397					    IIO_EV_TYPE_THRESH,
398					    IIO_EV_DIR_EITHER),
399		       iio_get_time_ns());
400
401	apds9300_clear_intr(data);
402
403	return IRQ_HANDLED;
404}
405
406static int apds9300_probe(struct i2c_client *client,
407		const struct i2c_device_id *id)
408{
409	struct apds9300_data *data;
410	struct iio_dev *indio_dev;
411	int ret;
412
413	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
414	if (!indio_dev)
415		return -ENOMEM;
416
417	data = iio_priv(indio_dev);
418	i2c_set_clientdata(client, indio_dev);
419	data->client = client;
420
421	ret = apds9300_chip_init(data);
422	if (ret < 0)
423		goto err;
424
425	mutex_init(&data->mutex);
426
427	indio_dev->dev.parent = &client->dev;
428	indio_dev->channels = apds9300_channels;
429	indio_dev->num_channels = ARRAY_SIZE(apds9300_channels);
430	indio_dev->name = APDS9300_DRV_NAME;
431	indio_dev->modes = INDIO_DIRECT_MODE;
432
433	if (client->irq)
434		indio_dev->info = &apds9300_info;
435	else
436		indio_dev->info = &apds9300_info_no_irq;
437
438	if (client->irq) {
439		ret = devm_request_threaded_irq(&client->dev, client->irq,
440				NULL, apds9300_interrupt_handler,
441				IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
442				APDS9300_IRQ_NAME, indio_dev);
443		if (ret) {
444			dev_err(&client->dev, "irq request error %d\n", -ret);
445			goto err;
446		}
447	}
448
449	ret = iio_device_register(indio_dev);
450	if (ret < 0)
451		goto err;
452
453	return 0;
454
455err:
456	/* Ensure that power off in case of error */
457	apds9300_set_power_state(data, 0);
458	return ret;
459}
460
461static int apds9300_remove(struct i2c_client *client)
462{
463	struct iio_dev *indio_dev = i2c_get_clientdata(client);
464	struct apds9300_data *data = iio_priv(indio_dev);
465
466	iio_device_unregister(indio_dev);
467
468	/* Ensure that power off and interrupts are disabled */
469	apds9300_set_intr_state(data, 0);
470	apds9300_set_power_state(data, 0);
471
472	return 0;
473}
474
475#ifdef CONFIG_PM_SLEEP
476static int apds9300_suspend(struct device *dev)
477{
478	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
479	struct apds9300_data *data = iio_priv(indio_dev);
480	int ret;
481
482	mutex_lock(&data->mutex);
483	ret = apds9300_set_power_state(data, 0);
484	mutex_unlock(&data->mutex);
485
486	return ret;
487}
488
489static int apds9300_resume(struct device *dev)
490{
491	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
492	struct apds9300_data *data = iio_priv(indio_dev);
493	int ret;
494
495	mutex_lock(&data->mutex);
496	ret = apds9300_set_power_state(data, 1);
497	mutex_unlock(&data->mutex);
498
499	return ret;
500}
501
502static SIMPLE_DEV_PM_OPS(apds9300_pm_ops, apds9300_suspend, apds9300_resume);
503#define APDS9300_PM_OPS (&apds9300_pm_ops)
504#else
505#define APDS9300_PM_OPS NULL
506#endif
507
508static struct i2c_device_id apds9300_id[] = {
509	{ APDS9300_DRV_NAME, 0 },
510	{ }
511};
512
513MODULE_DEVICE_TABLE(i2c, apds9300_id);
514
515static struct i2c_driver apds9300_driver = {
516	.driver = {
517		.name	= APDS9300_DRV_NAME,
518		.owner	= THIS_MODULE,
519		.pm	= APDS9300_PM_OPS,
520	},
521	.probe		= apds9300_probe,
522	.remove		= apds9300_remove,
523	.id_table	= apds9300_id,
524};
525
526module_i2c_driver(apds9300_driver);
527
528MODULE_AUTHOR("Kravchenko Oleksandr <o.v.kravchenko@globallogic.com>");
529MODULE_AUTHOR("GlobalLogic inc.");
530MODULE_DESCRIPTION("APDS9300 ambient light photo sensor driver");
531MODULE_LICENSE("GPL");
532