xref: /openbmc/linux/drivers/iio/light/stk3310.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /**
3  * Sensortek STK3310/STK3311 Ambient Light and Proximity Sensor
4  *
5  * Copyright (c) 2015, Intel Corporation.
6  *
7  * IIO driver for STK3310/STK3311. 7-bit I2C address: 0x48.
8  */
9 
10 #include <linux/acpi.h>
11 #include <linux/i2c.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/regmap.h>
16 #include <linux/iio/events.h>
17 #include <linux/iio/iio.h>
18 #include <linux/iio/sysfs.h>
19 
20 #define STK3310_REG_STATE			0x00
21 #define STK3310_REG_PSCTRL			0x01
22 #define STK3310_REG_ALSCTRL			0x02
23 #define STK3310_REG_INT				0x04
24 #define STK3310_REG_THDH_PS			0x06
25 #define STK3310_REG_THDL_PS			0x08
26 #define STK3310_REG_FLAG			0x10
27 #define STK3310_REG_PS_DATA_MSB			0x11
28 #define STK3310_REG_PS_DATA_LSB			0x12
29 #define STK3310_REG_ALS_DATA_MSB		0x13
30 #define STK3310_REG_ALS_DATA_LSB		0x14
31 #define STK3310_REG_ID				0x3E
32 #define STK3310_MAX_REG				0x80
33 
34 #define STK3310_STATE_EN_PS			BIT(0)
35 #define STK3310_STATE_EN_ALS			BIT(1)
36 #define STK3310_STATE_STANDBY			0x00
37 
38 #define STK3310_CHIP_ID_VAL			0x13
39 #define STK3311_CHIP_ID_VAL			0x1D
40 #define STK3335_CHIP_ID_VAL			0x51
41 #define STK3310_PSINT_EN			0x01
42 #define STK3310_PS_MAX_VAL			0xFFFF
43 
44 #define STK3310_DRIVER_NAME			"stk3310"
45 #define STK3310_REGMAP_NAME			"stk3310_regmap"
46 #define STK3310_EVENT				"stk3310_event"
47 
48 #define STK3310_SCALE_AVAILABLE			"6.4 1.6 0.4 0.1"
49 
50 #define STK3310_IT_AVAILABLE \
51 	"0.000185 0.000370 0.000741 0.001480 0.002960 0.005920 0.011840 " \
52 	"0.023680 0.047360 0.094720 0.189440 0.378880 0.757760 1.515520 " \
53 	"3.031040 6.062080"
54 
55 #define STK3310_REGFIELD(name)						    \
56 	do {								    \
57 		data->reg_##name =					    \
58 			devm_regmap_field_alloc(&client->dev, regmap,	    \
59 				stk3310_reg_field_##name);		    \
60 		if (IS_ERR(data->reg_##name)) {				    \
61 			dev_err(&client->dev, "reg field alloc failed.\n"); \
62 			return PTR_ERR(data->reg_##name);		    \
63 		}							    \
64 	} while (0)
65 
66 static const struct reg_field stk3310_reg_field_state =
67 				REG_FIELD(STK3310_REG_STATE, 0, 2);
68 static const struct reg_field stk3310_reg_field_als_gain =
69 				REG_FIELD(STK3310_REG_ALSCTRL, 4, 5);
70 static const struct reg_field stk3310_reg_field_ps_gain =
71 				REG_FIELD(STK3310_REG_PSCTRL, 4, 5);
72 static const struct reg_field stk3310_reg_field_als_it =
73 				REG_FIELD(STK3310_REG_ALSCTRL, 0, 3);
74 static const struct reg_field stk3310_reg_field_ps_it =
75 				REG_FIELD(STK3310_REG_PSCTRL, 0, 3);
76 static const struct reg_field stk3310_reg_field_int_ps =
77 				REG_FIELD(STK3310_REG_INT, 0, 2);
78 static const struct reg_field stk3310_reg_field_flag_psint =
79 				REG_FIELD(STK3310_REG_FLAG, 4, 4);
80 static const struct reg_field stk3310_reg_field_flag_nf =
81 				REG_FIELD(STK3310_REG_FLAG, 0, 0);
82 
83 /* Estimate maximum proximity values with regard to measurement scale. */
84 static const int stk3310_ps_max[4] = {
85 	STK3310_PS_MAX_VAL / 640,
86 	STK3310_PS_MAX_VAL / 160,
87 	STK3310_PS_MAX_VAL /  40,
88 	STK3310_PS_MAX_VAL /  10
89 };
90 
91 static const int stk3310_scale_table[][2] = {
92 	{6, 400000}, {1, 600000}, {0, 400000}, {0, 100000}
93 };
94 
95 /* Integration time in seconds, microseconds */
96 static const int stk3310_it_table[][2] = {
97 	{0, 185},	{0, 370},	{0, 741},	{0, 1480},
98 	{0, 2960},	{0, 5920},	{0, 11840},	{0, 23680},
99 	{0, 47360},	{0, 94720},	{0, 189440},	{0, 378880},
100 	{0, 757760},	{1, 515520},	{3, 31040},	{6, 62080},
101 };
102 
103 struct stk3310_data {
104 	struct i2c_client *client;
105 	struct mutex lock;
106 	bool als_enabled;
107 	bool ps_enabled;
108 	u64 timestamp;
109 	struct regmap *regmap;
110 	struct regmap_field *reg_state;
111 	struct regmap_field *reg_als_gain;
112 	struct regmap_field *reg_ps_gain;
113 	struct regmap_field *reg_als_it;
114 	struct regmap_field *reg_ps_it;
115 	struct regmap_field *reg_int_ps;
116 	struct regmap_field *reg_flag_psint;
117 	struct regmap_field *reg_flag_nf;
118 };
119 
120 static const struct iio_event_spec stk3310_events[] = {
121 	/* Proximity event */
122 	{
123 		.type = IIO_EV_TYPE_THRESH,
124 		.dir = IIO_EV_DIR_RISING,
125 		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
126 				 BIT(IIO_EV_INFO_ENABLE),
127 	},
128 	/* Out-of-proximity event */
129 	{
130 		.type = IIO_EV_TYPE_THRESH,
131 		.dir = IIO_EV_DIR_FALLING,
132 		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
133 				 BIT(IIO_EV_INFO_ENABLE),
134 	},
135 };
136 
137 static const struct iio_chan_spec stk3310_channels[] = {
138 	{
139 		.type = IIO_LIGHT,
140 		.info_mask_separate =
141 			BIT(IIO_CHAN_INFO_RAW) |
142 			BIT(IIO_CHAN_INFO_SCALE) |
143 			BIT(IIO_CHAN_INFO_INT_TIME),
144 	},
145 	{
146 		.type = IIO_PROXIMITY,
147 		.info_mask_separate =
148 			BIT(IIO_CHAN_INFO_RAW) |
149 			BIT(IIO_CHAN_INFO_SCALE) |
150 			BIT(IIO_CHAN_INFO_INT_TIME),
151 		.event_spec = stk3310_events,
152 		.num_event_specs = ARRAY_SIZE(stk3310_events),
153 	}
154 };
155 
156 static IIO_CONST_ATTR(in_illuminance_scale_available, STK3310_SCALE_AVAILABLE);
157 
158 static IIO_CONST_ATTR(in_proximity_scale_available, STK3310_SCALE_AVAILABLE);
159 
160 static IIO_CONST_ATTR(in_illuminance_integration_time_available,
161 		      STK3310_IT_AVAILABLE);
162 
163 static IIO_CONST_ATTR(in_proximity_integration_time_available,
164 		      STK3310_IT_AVAILABLE);
165 
166 static struct attribute *stk3310_attributes[] = {
167 	&iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
168 	&iio_const_attr_in_proximity_scale_available.dev_attr.attr,
169 	&iio_const_attr_in_illuminance_integration_time_available.dev_attr.attr,
170 	&iio_const_attr_in_proximity_integration_time_available.dev_attr.attr,
171 	NULL,
172 };
173 
174 static const struct attribute_group stk3310_attribute_group = {
175 	.attrs = stk3310_attributes
176 };
177 
178 static int stk3310_get_index(const int table[][2], int table_size,
179 			     int val, int val2)
180 {
181 	int i;
182 
183 	for (i = 0; i < table_size; i++) {
184 		if (val == table[i][0] && val2 == table[i][1])
185 			return i;
186 	}
187 
188 	return -EINVAL;
189 }
190 
191 static int stk3310_read_event(struct iio_dev *indio_dev,
192 			      const struct iio_chan_spec *chan,
193 			      enum iio_event_type type,
194 			      enum iio_event_direction dir,
195 			      enum iio_event_info info,
196 			      int *val, int *val2)
197 {
198 	u8 reg;
199 	__be16 buf;
200 	int ret;
201 	struct stk3310_data *data = iio_priv(indio_dev);
202 
203 	if (info != IIO_EV_INFO_VALUE)
204 		return -EINVAL;
205 
206 	/* Only proximity interrupts are implemented at the moment. */
207 	if (dir == IIO_EV_DIR_RISING)
208 		reg = STK3310_REG_THDH_PS;
209 	else if (dir == IIO_EV_DIR_FALLING)
210 		reg = STK3310_REG_THDL_PS;
211 	else
212 		return -EINVAL;
213 
214 	mutex_lock(&data->lock);
215 	ret = regmap_bulk_read(data->regmap, reg, &buf, 2);
216 	mutex_unlock(&data->lock);
217 	if (ret < 0) {
218 		dev_err(&data->client->dev, "register read failed\n");
219 		return ret;
220 	}
221 	*val = be16_to_cpu(buf);
222 
223 	return IIO_VAL_INT;
224 }
225 
226 static int stk3310_write_event(struct iio_dev *indio_dev,
227 			       const struct iio_chan_spec *chan,
228 			       enum iio_event_type type,
229 			       enum iio_event_direction dir,
230 			       enum iio_event_info info,
231 			       int val, int val2)
232 {
233 	u8 reg;
234 	__be16 buf;
235 	int ret;
236 	unsigned int index;
237 	struct stk3310_data *data = iio_priv(indio_dev);
238 	struct i2c_client *client = data->client;
239 
240 	ret = regmap_field_read(data->reg_ps_gain, &index);
241 	if (ret < 0)
242 		return ret;
243 
244 	if (val < 0 || val > stk3310_ps_max[index])
245 		return -EINVAL;
246 
247 	if (dir == IIO_EV_DIR_RISING)
248 		reg = STK3310_REG_THDH_PS;
249 	else if (dir == IIO_EV_DIR_FALLING)
250 		reg = STK3310_REG_THDL_PS;
251 	else
252 		return -EINVAL;
253 
254 	buf = cpu_to_be16(val);
255 	ret = regmap_bulk_write(data->regmap, reg, &buf, 2);
256 	if (ret < 0)
257 		dev_err(&client->dev, "failed to set PS threshold!\n");
258 
259 	return ret;
260 }
261 
262 static int stk3310_read_event_config(struct iio_dev *indio_dev,
263 				     const struct iio_chan_spec *chan,
264 				     enum iio_event_type type,
265 				     enum iio_event_direction dir)
266 {
267 	unsigned int event_val;
268 	int ret;
269 	struct stk3310_data *data = iio_priv(indio_dev);
270 
271 	ret = regmap_field_read(data->reg_int_ps, &event_val);
272 	if (ret < 0)
273 		return ret;
274 
275 	return event_val;
276 }
277 
278 static int stk3310_write_event_config(struct iio_dev *indio_dev,
279 				      const struct iio_chan_spec *chan,
280 				      enum iio_event_type type,
281 				      enum iio_event_direction dir,
282 				      int state)
283 {
284 	int ret;
285 	struct stk3310_data *data = iio_priv(indio_dev);
286 	struct i2c_client *client = data->client;
287 
288 	if (state < 0 || state > 7)
289 		return -EINVAL;
290 
291 	/* Set INT_PS value */
292 	mutex_lock(&data->lock);
293 	ret = regmap_field_write(data->reg_int_ps, state);
294 	if (ret < 0)
295 		dev_err(&client->dev, "failed to set interrupt mode\n");
296 	mutex_unlock(&data->lock);
297 
298 	return ret;
299 }
300 
301 static int stk3310_read_raw(struct iio_dev *indio_dev,
302 			    struct iio_chan_spec const *chan,
303 			    int *val, int *val2, long mask)
304 {
305 	u8 reg;
306 	__be16 buf;
307 	int ret;
308 	unsigned int index;
309 	struct stk3310_data *data = iio_priv(indio_dev);
310 	struct i2c_client *client = data->client;
311 
312 	if (chan->type != IIO_LIGHT && chan->type != IIO_PROXIMITY)
313 		return -EINVAL;
314 
315 	switch (mask) {
316 	case IIO_CHAN_INFO_RAW:
317 		if (chan->type == IIO_LIGHT)
318 			reg = STK3310_REG_ALS_DATA_MSB;
319 		else
320 			reg = STK3310_REG_PS_DATA_MSB;
321 
322 		mutex_lock(&data->lock);
323 		ret = regmap_bulk_read(data->regmap, reg, &buf, 2);
324 		if (ret < 0) {
325 			dev_err(&client->dev, "register read failed\n");
326 			mutex_unlock(&data->lock);
327 			return ret;
328 		}
329 		*val = be16_to_cpu(buf);
330 		mutex_unlock(&data->lock);
331 		return IIO_VAL_INT;
332 	case IIO_CHAN_INFO_INT_TIME:
333 		if (chan->type == IIO_LIGHT)
334 			ret = regmap_field_read(data->reg_als_it, &index);
335 		else
336 			ret = regmap_field_read(data->reg_ps_it, &index);
337 		if (ret < 0)
338 			return ret;
339 
340 		*val = stk3310_it_table[index][0];
341 		*val2 = stk3310_it_table[index][1];
342 		return IIO_VAL_INT_PLUS_MICRO;
343 	case IIO_CHAN_INFO_SCALE:
344 		if (chan->type == IIO_LIGHT)
345 			ret = regmap_field_read(data->reg_als_gain, &index);
346 		else
347 			ret = regmap_field_read(data->reg_ps_gain, &index);
348 		if (ret < 0)
349 			return ret;
350 
351 		*val = stk3310_scale_table[index][0];
352 		*val2 = stk3310_scale_table[index][1];
353 		return IIO_VAL_INT_PLUS_MICRO;
354 	}
355 
356 	return -EINVAL;
357 }
358 
359 static int stk3310_write_raw(struct iio_dev *indio_dev,
360 			     struct iio_chan_spec const *chan,
361 			     int val, int val2, long mask)
362 {
363 	int ret;
364 	int index;
365 	struct stk3310_data *data = iio_priv(indio_dev);
366 
367 	if (chan->type != IIO_LIGHT && chan->type != IIO_PROXIMITY)
368 		return -EINVAL;
369 
370 	switch (mask) {
371 	case IIO_CHAN_INFO_INT_TIME:
372 		index = stk3310_get_index(stk3310_it_table,
373 					  ARRAY_SIZE(stk3310_it_table),
374 					  val, val2);
375 		if (index < 0)
376 			return -EINVAL;
377 		mutex_lock(&data->lock);
378 		if (chan->type == IIO_LIGHT)
379 			ret = regmap_field_write(data->reg_als_it, index);
380 		else
381 			ret = regmap_field_write(data->reg_ps_it, index);
382 		if (ret < 0)
383 			dev_err(&data->client->dev,
384 				"sensor configuration failed\n");
385 		mutex_unlock(&data->lock);
386 		return ret;
387 
388 	case IIO_CHAN_INFO_SCALE:
389 		index = stk3310_get_index(stk3310_scale_table,
390 					  ARRAY_SIZE(stk3310_scale_table),
391 					  val, val2);
392 		if (index < 0)
393 			return -EINVAL;
394 		mutex_lock(&data->lock);
395 		if (chan->type == IIO_LIGHT)
396 			ret = regmap_field_write(data->reg_als_gain, index);
397 		else
398 			ret = regmap_field_write(data->reg_ps_gain, index);
399 		if (ret < 0)
400 			dev_err(&data->client->dev,
401 				"sensor configuration failed\n");
402 		mutex_unlock(&data->lock);
403 		return ret;
404 	}
405 
406 	return -EINVAL;
407 }
408 
409 static const struct iio_info stk3310_info = {
410 	.read_raw		= stk3310_read_raw,
411 	.write_raw		= stk3310_write_raw,
412 	.attrs			= &stk3310_attribute_group,
413 	.read_event_value	= stk3310_read_event,
414 	.write_event_value	= stk3310_write_event,
415 	.read_event_config	= stk3310_read_event_config,
416 	.write_event_config	= stk3310_write_event_config,
417 };
418 
419 static int stk3310_set_state(struct stk3310_data *data, u8 state)
420 {
421 	int ret;
422 	struct i2c_client *client = data->client;
423 
424 	/* 3-bit state; 0b100 is not supported. */
425 	if (state > 7 || state == 4)
426 		return -EINVAL;
427 
428 	mutex_lock(&data->lock);
429 	ret = regmap_field_write(data->reg_state, state);
430 	if (ret < 0) {
431 		dev_err(&client->dev, "failed to change sensor state\n");
432 	} else if (state != STK3310_STATE_STANDBY) {
433 		/* Don't reset the 'enabled' flags if we're going in standby */
434 		data->ps_enabled  = !!(state & STK3310_STATE_EN_PS);
435 		data->als_enabled = !!(state & STK3310_STATE_EN_ALS);
436 	}
437 	mutex_unlock(&data->lock);
438 
439 	return ret;
440 }
441 
442 static int stk3310_init(struct iio_dev *indio_dev)
443 {
444 	int ret;
445 	int chipid;
446 	u8 state;
447 	struct stk3310_data *data = iio_priv(indio_dev);
448 	struct i2c_client *client = data->client;
449 
450 	ret = regmap_read(data->regmap, STK3310_REG_ID, &chipid);
451 	if (ret < 0)
452 		return ret;
453 
454 	if (chipid != STK3310_CHIP_ID_VAL &&
455 	    chipid != STK3311_CHIP_ID_VAL &&
456 	    chipid != STK3335_CHIP_ID_VAL) {
457 		dev_err(&client->dev, "invalid chip id: 0x%x\n", chipid);
458 		return -ENODEV;
459 	}
460 
461 	state = STK3310_STATE_EN_ALS | STK3310_STATE_EN_PS;
462 	ret = stk3310_set_state(data, state);
463 	if (ret < 0) {
464 		dev_err(&client->dev, "failed to enable sensor");
465 		return ret;
466 	}
467 
468 	/* Enable PS interrupts */
469 	ret = regmap_field_write(data->reg_int_ps, STK3310_PSINT_EN);
470 	if (ret < 0)
471 		dev_err(&client->dev, "failed to enable interrupts!\n");
472 
473 	return ret;
474 }
475 
476 static bool stk3310_is_volatile_reg(struct device *dev, unsigned int reg)
477 {
478 	switch (reg) {
479 	case STK3310_REG_ALS_DATA_MSB:
480 	case STK3310_REG_ALS_DATA_LSB:
481 	case STK3310_REG_PS_DATA_LSB:
482 	case STK3310_REG_PS_DATA_MSB:
483 	case STK3310_REG_FLAG:
484 		return true;
485 	default:
486 		return false;
487 	}
488 }
489 
490 static struct regmap_config stk3310_regmap_config = {
491 	.name = STK3310_REGMAP_NAME,
492 	.reg_bits = 8,
493 	.val_bits = 8,
494 	.max_register = STK3310_MAX_REG,
495 	.cache_type = REGCACHE_RBTREE,
496 	.volatile_reg = stk3310_is_volatile_reg,
497 };
498 
499 static int stk3310_regmap_init(struct stk3310_data *data)
500 {
501 	struct regmap *regmap;
502 	struct i2c_client *client;
503 
504 	client = data->client;
505 	regmap = devm_regmap_init_i2c(client, &stk3310_regmap_config);
506 	if (IS_ERR(regmap)) {
507 		dev_err(&client->dev, "regmap initialization failed.\n");
508 		return PTR_ERR(regmap);
509 	}
510 	data->regmap = regmap;
511 
512 	STK3310_REGFIELD(state);
513 	STK3310_REGFIELD(als_gain);
514 	STK3310_REGFIELD(ps_gain);
515 	STK3310_REGFIELD(als_it);
516 	STK3310_REGFIELD(ps_it);
517 	STK3310_REGFIELD(int_ps);
518 	STK3310_REGFIELD(flag_psint);
519 	STK3310_REGFIELD(flag_nf);
520 
521 	return 0;
522 }
523 
524 static irqreturn_t stk3310_irq_handler(int irq, void *private)
525 {
526 	struct iio_dev *indio_dev = private;
527 	struct stk3310_data *data = iio_priv(indio_dev);
528 
529 	data->timestamp = iio_get_time_ns(indio_dev);
530 
531 	return IRQ_WAKE_THREAD;
532 }
533 
534 static irqreturn_t stk3310_irq_event_handler(int irq, void *private)
535 {
536 	int ret;
537 	unsigned int dir;
538 	u64 event;
539 
540 	struct iio_dev *indio_dev = private;
541 	struct stk3310_data *data = iio_priv(indio_dev);
542 
543 	/* Read FLAG_NF to figure out what threshold has been met. */
544 	mutex_lock(&data->lock);
545 	ret = regmap_field_read(data->reg_flag_nf, &dir);
546 	if (ret < 0) {
547 		dev_err(&data->client->dev, "register read failed\n");
548 		mutex_unlock(&data->lock);
549 		return ret;
550 	}
551 	event = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 1,
552 				     IIO_EV_TYPE_THRESH,
553 				     (dir ? IIO_EV_DIR_FALLING :
554 					    IIO_EV_DIR_RISING));
555 	iio_push_event(indio_dev, event, data->timestamp);
556 
557 	/* Reset the interrupt flag */
558 	ret = regmap_field_write(data->reg_flag_psint, 0);
559 	if (ret < 0)
560 		dev_err(&data->client->dev, "failed to reset interrupts\n");
561 	mutex_unlock(&data->lock);
562 
563 	return IRQ_HANDLED;
564 }
565 
566 static int stk3310_probe(struct i2c_client *client,
567 			 const struct i2c_device_id *id)
568 {
569 	int ret;
570 	struct iio_dev *indio_dev;
571 	struct stk3310_data *data;
572 
573 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
574 	if (!indio_dev) {
575 		dev_err(&client->dev, "iio allocation failed!\n");
576 		return -ENOMEM;
577 	}
578 
579 	data = iio_priv(indio_dev);
580 	data->client = client;
581 	i2c_set_clientdata(client, indio_dev);
582 	mutex_init(&data->lock);
583 
584 	ret = stk3310_regmap_init(data);
585 	if (ret < 0)
586 		return ret;
587 
588 	indio_dev->dev.parent = &client->dev;
589 	indio_dev->info = &stk3310_info;
590 	indio_dev->name = STK3310_DRIVER_NAME;
591 	indio_dev->modes = INDIO_DIRECT_MODE;
592 	indio_dev->channels = stk3310_channels;
593 	indio_dev->num_channels = ARRAY_SIZE(stk3310_channels);
594 
595 	ret = stk3310_init(indio_dev);
596 	if (ret < 0)
597 		return ret;
598 
599 	if (client->irq > 0) {
600 		ret = devm_request_threaded_irq(&client->dev, client->irq,
601 						stk3310_irq_handler,
602 						stk3310_irq_event_handler,
603 						IRQF_TRIGGER_FALLING |
604 						IRQF_ONESHOT,
605 						STK3310_EVENT, indio_dev);
606 		if (ret < 0) {
607 			dev_err(&client->dev, "request irq %d failed\n",
608 				client->irq);
609 			goto err_standby;
610 		}
611 	}
612 
613 	ret = iio_device_register(indio_dev);
614 	if (ret < 0) {
615 		dev_err(&client->dev, "device_register failed\n");
616 		goto err_standby;
617 	}
618 
619 	return 0;
620 
621 err_standby:
622 	stk3310_set_state(data, STK3310_STATE_STANDBY);
623 	return ret;
624 }
625 
626 static int stk3310_remove(struct i2c_client *client)
627 {
628 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
629 
630 	iio_device_unregister(indio_dev);
631 	return stk3310_set_state(iio_priv(indio_dev), STK3310_STATE_STANDBY);
632 }
633 
634 #ifdef CONFIG_PM_SLEEP
635 static int stk3310_suspend(struct device *dev)
636 {
637 	struct stk3310_data *data;
638 
639 	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
640 
641 	return stk3310_set_state(data, STK3310_STATE_STANDBY);
642 }
643 
644 static int stk3310_resume(struct device *dev)
645 {
646 	u8 state = 0;
647 	struct stk3310_data *data;
648 
649 	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
650 	if (data->ps_enabled)
651 		state |= STK3310_STATE_EN_PS;
652 	if (data->als_enabled)
653 		state |= STK3310_STATE_EN_ALS;
654 
655 	return stk3310_set_state(data, state);
656 }
657 
658 static SIMPLE_DEV_PM_OPS(stk3310_pm_ops, stk3310_suspend, stk3310_resume);
659 
660 #define STK3310_PM_OPS (&stk3310_pm_ops)
661 #else
662 #define STK3310_PM_OPS NULL
663 #endif
664 
665 static const struct i2c_device_id stk3310_i2c_id[] = {
666 	{"STK3310", 0},
667 	{"STK3311", 0},
668 	{"STK3335", 0},
669 	{}
670 };
671 MODULE_DEVICE_TABLE(i2c, stk3310_i2c_id);
672 
673 static const struct acpi_device_id stk3310_acpi_id[] = {
674 	{"STK3310", 0},
675 	{"STK3311", 0},
676 	{"STK3335", 0},
677 	{}
678 };
679 
680 MODULE_DEVICE_TABLE(acpi, stk3310_acpi_id);
681 
682 static struct i2c_driver stk3310_driver = {
683 	.driver = {
684 		.name = "stk3310",
685 		.pm = STK3310_PM_OPS,
686 		.acpi_match_table = ACPI_PTR(stk3310_acpi_id),
687 	},
688 	.probe =            stk3310_probe,
689 	.remove =           stk3310_remove,
690 	.id_table =         stk3310_i2c_id,
691 };
692 
693 module_i2c_driver(stk3310_driver);
694 
695 MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
696 MODULE_DESCRIPTION("STK3310 Ambient Light and Proximity Sensor driver");
697 MODULE_LICENSE("GPL v2");
698