xref: /openbmc/linux/drivers/iio/light/stk3310.c (revision bc5aa3a0)
1 /**
2  * Sensortek STK3310/STK3311 Ambient Light and Proximity Sensor
3  *
4  * Copyright (c) 2015, Intel Corporation.
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  * IIO driver for STK3310/STK3311. 7-bit I2C address: 0x48.
11  */
12 
13 #include <linux/acpi.h>
14 #include <linux/i2c.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/regmap.h>
19 #include <linux/iio/events.h>
20 #include <linux/iio/iio.h>
21 #include <linux/iio/sysfs.h>
22 
23 #define STK3310_REG_STATE			0x00
24 #define STK3310_REG_PSCTRL			0x01
25 #define STK3310_REG_ALSCTRL			0x02
26 #define STK3310_REG_INT				0x04
27 #define STK3310_REG_THDH_PS			0x06
28 #define STK3310_REG_THDL_PS			0x08
29 #define STK3310_REG_FLAG			0x10
30 #define STK3310_REG_PS_DATA_MSB			0x11
31 #define STK3310_REG_PS_DATA_LSB			0x12
32 #define STK3310_REG_ALS_DATA_MSB		0x13
33 #define STK3310_REG_ALS_DATA_LSB		0x14
34 #define STK3310_REG_ID				0x3E
35 #define STK3310_MAX_REG				0x80
36 
37 #define STK3310_STATE_EN_PS			BIT(0)
38 #define STK3310_STATE_EN_ALS			BIT(1)
39 #define STK3310_STATE_STANDBY			0x00
40 
41 #define STK3310_CHIP_ID_VAL			0x13
42 #define STK3311_CHIP_ID_VAL			0x1D
43 #define STK3310_PSINT_EN			0x01
44 #define STK3310_PS_MAX_VAL			0xFFFF
45 
46 #define STK3310_DRIVER_NAME			"stk3310"
47 #define STK3310_REGMAP_NAME			"stk3310_regmap"
48 #define STK3310_EVENT				"stk3310_event"
49 
50 #define STK3310_SCALE_AVAILABLE			"6.4 1.6 0.4 0.1"
51 
52 #define STK3310_IT_AVAILABLE \
53 	"0.000185 0.000370 0.000741 0.001480 0.002960 0.005920 0.011840 " \
54 	"0.023680 0.047360 0.094720 0.189440 0.378880 0.757760 1.515520 " \
55 	"3.031040 6.062080"
56 
57 #define STK3310_REGFIELD(name)						    \
58 	do {								    \
59 		data->reg_##name =					    \
60 			devm_regmap_field_alloc(&client->dev, regmap,	    \
61 				stk3310_reg_field_##name);		    \
62 		if (IS_ERR(data->reg_##name)) {				    \
63 			dev_err(&client->dev, "reg field alloc failed.\n"); \
64 			return PTR_ERR(data->reg_##name);		    \
65 		}							    \
66 	} while (0)
67 
68 static const struct reg_field stk3310_reg_field_state =
69 				REG_FIELD(STK3310_REG_STATE, 0, 2);
70 static const struct reg_field stk3310_reg_field_als_gain =
71 				REG_FIELD(STK3310_REG_ALSCTRL, 4, 5);
72 static const struct reg_field stk3310_reg_field_ps_gain =
73 				REG_FIELD(STK3310_REG_PSCTRL, 4, 5);
74 static const struct reg_field stk3310_reg_field_als_it =
75 				REG_FIELD(STK3310_REG_ALSCTRL, 0, 3);
76 static const struct reg_field stk3310_reg_field_ps_it =
77 				REG_FIELD(STK3310_REG_PSCTRL, 0, 3);
78 static const struct reg_field stk3310_reg_field_int_ps =
79 				REG_FIELD(STK3310_REG_INT, 0, 2);
80 static const struct reg_field stk3310_reg_field_flag_psint =
81 				REG_FIELD(STK3310_REG_FLAG, 4, 4);
82 static const struct reg_field stk3310_reg_field_flag_nf =
83 				REG_FIELD(STK3310_REG_FLAG, 0, 0);
84 
85 /* Estimate maximum proximity values with regard to measurement scale. */
86 static const int stk3310_ps_max[4] = {
87 	STK3310_PS_MAX_VAL / 640,
88 	STK3310_PS_MAX_VAL / 160,
89 	STK3310_PS_MAX_VAL /  40,
90 	STK3310_PS_MAX_VAL /  10
91 };
92 
93 static const int stk3310_scale_table[][2] = {
94 	{6, 400000}, {1, 600000}, {0, 400000}, {0, 100000}
95 };
96 
97 /* Integration time in seconds, microseconds */
98 static const int stk3310_it_table[][2] = {
99 	{0, 185},	{0, 370},	{0, 741},	{0, 1480},
100 	{0, 2960},	{0, 5920},	{0, 11840},	{0, 23680},
101 	{0, 47360},	{0, 94720},	{0, 189440},	{0, 378880},
102 	{0, 757760},	{1, 515520},	{3, 31040},	{6, 62080},
103 };
104 
105 struct stk3310_data {
106 	struct i2c_client *client;
107 	struct mutex lock;
108 	bool als_enabled;
109 	bool ps_enabled;
110 	u64 timestamp;
111 	struct regmap *regmap;
112 	struct regmap_field *reg_state;
113 	struct regmap_field *reg_als_gain;
114 	struct regmap_field *reg_ps_gain;
115 	struct regmap_field *reg_als_it;
116 	struct regmap_field *reg_ps_it;
117 	struct regmap_field *reg_int_ps;
118 	struct regmap_field *reg_flag_psint;
119 	struct regmap_field *reg_flag_nf;
120 };
121 
122 static const struct iio_event_spec stk3310_events[] = {
123 	/* Proximity event */
124 	{
125 		.type = IIO_EV_TYPE_THRESH,
126 		.dir = IIO_EV_DIR_RISING,
127 		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
128 				 BIT(IIO_EV_INFO_ENABLE),
129 	},
130 	/* Out-of-proximity event */
131 	{
132 		.type = IIO_EV_TYPE_THRESH,
133 		.dir = IIO_EV_DIR_FALLING,
134 		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
135 				 BIT(IIO_EV_INFO_ENABLE),
136 	},
137 };
138 
139 static const struct iio_chan_spec stk3310_channels[] = {
140 	{
141 		.type = IIO_LIGHT,
142 		.info_mask_separate =
143 			BIT(IIO_CHAN_INFO_RAW) |
144 			BIT(IIO_CHAN_INFO_SCALE) |
145 			BIT(IIO_CHAN_INFO_INT_TIME),
146 	},
147 	{
148 		.type = IIO_PROXIMITY,
149 		.info_mask_separate =
150 			BIT(IIO_CHAN_INFO_RAW) |
151 			BIT(IIO_CHAN_INFO_SCALE) |
152 			BIT(IIO_CHAN_INFO_INT_TIME),
153 		.event_spec = stk3310_events,
154 		.num_event_specs = ARRAY_SIZE(stk3310_events),
155 	}
156 };
157 
158 static IIO_CONST_ATTR(in_illuminance_scale_available, STK3310_SCALE_AVAILABLE);
159 
160 static IIO_CONST_ATTR(in_proximity_scale_available, STK3310_SCALE_AVAILABLE);
161 
162 static IIO_CONST_ATTR(in_illuminance_integration_time_available,
163 		      STK3310_IT_AVAILABLE);
164 
165 static IIO_CONST_ATTR(in_proximity_integration_time_available,
166 		      STK3310_IT_AVAILABLE);
167 
168 static struct attribute *stk3310_attributes[] = {
169 	&iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
170 	&iio_const_attr_in_proximity_scale_available.dev_attr.attr,
171 	&iio_const_attr_in_illuminance_integration_time_available.dev_attr.attr,
172 	&iio_const_attr_in_proximity_integration_time_available.dev_attr.attr,
173 	NULL,
174 };
175 
176 static const struct attribute_group stk3310_attribute_group = {
177 	.attrs = stk3310_attributes
178 };
179 
180 static int stk3310_get_index(const int table[][2], int table_size,
181 			     int val, int val2)
182 {
183 	int i;
184 
185 	for (i = 0; i < table_size; i++) {
186 		if (val == table[i][0] && val2 == table[i][1])
187 			return i;
188 	}
189 
190 	return -EINVAL;
191 }
192 
193 static int stk3310_read_event(struct iio_dev *indio_dev,
194 			      const struct iio_chan_spec *chan,
195 			      enum iio_event_type type,
196 			      enum iio_event_direction dir,
197 			      enum iio_event_info info,
198 			      int *val, int *val2)
199 {
200 	u8 reg;
201 	__be16 buf;
202 	int ret;
203 	struct stk3310_data *data = iio_priv(indio_dev);
204 
205 	if (info != IIO_EV_INFO_VALUE)
206 		return -EINVAL;
207 
208 	/* Only proximity interrupts are implemented at the moment. */
209 	if (dir == IIO_EV_DIR_RISING)
210 		reg = STK3310_REG_THDH_PS;
211 	else if (dir == IIO_EV_DIR_FALLING)
212 		reg = STK3310_REG_THDL_PS;
213 	else
214 		return -EINVAL;
215 
216 	mutex_lock(&data->lock);
217 	ret = regmap_bulk_read(data->regmap, reg, &buf, 2);
218 	mutex_unlock(&data->lock);
219 	if (ret < 0) {
220 		dev_err(&data->client->dev, "register read failed\n");
221 		return ret;
222 	}
223 	*val = be16_to_cpu(buf);
224 
225 	return IIO_VAL_INT;
226 }
227 
228 static int stk3310_write_event(struct iio_dev *indio_dev,
229 			       const struct iio_chan_spec *chan,
230 			       enum iio_event_type type,
231 			       enum iio_event_direction dir,
232 			       enum iio_event_info info,
233 			       int val, int val2)
234 {
235 	u8 reg;
236 	__be16 buf;
237 	int ret;
238 	unsigned int index;
239 	struct stk3310_data *data = iio_priv(indio_dev);
240 	struct i2c_client *client = data->client;
241 
242 	ret = regmap_field_read(data->reg_ps_gain, &index);
243 	if (ret < 0)
244 		return ret;
245 
246 	if (val < 0 || val > stk3310_ps_max[index])
247 		return -EINVAL;
248 
249 	if (dir == IIO_EV_DIR_RISING)
250 		reg = STK3310_REG_THDH_PS;
251 	else if (dir == IIO_EV_DIR_FALLING)
252 		reg = STK3310_REG_THDL_PS;
253 	else
254 		return -EINVAL;
255 
256 	buf = cpu_to_be16(val);
257 	ret = regmap_bulk_write(data->regmap, reg, &buf, 2);
258 	if (ret < 0)
259 		dev_err(&client->dev, "failed to set PS threshold!\n");
260 
261 	return ret;
262 }
263 
264 static int stk3310_read_event_config(struct iio_dev *indio_dev,
265 				     const struct iio_chan_spec *chan,
266 				     enum iio_event_type type,
267 				     enum iio_event_direction dir)
268 {
269 	unsigned int event_val;
270 	int ret;
271 	struct stk3310_data *data = iio_priv(indio_dev);
272 
273 	ret = regmap_field_read(data->reg_int_ps, &event_val);
274 	if (ret < 0)
275 		return ret;
276 
277 	return event_val;
278 }
279 
280 static int stk3310_write_event_config(struct iio_dev *indio_dev,
281 				      const struct iio_chan_spec *chan,
282 				      enum iio_event_type type,
283 				      enum iio_event_direction dir,
284 				      int state)
285 {
286 	int ret;
287 	struct stk3310_data *data = iio_priv(indio_dev);
288 	struct i2c_client *client = data->client;
289 
290 	if (state < 0 || state > 7)
291 		return -EINVAL;
292 
293 	/* Set INT_PS value */
294 	mutex_lock(&data->lock);
295 	ret = regmap_field_write(data->reg_int_ps, state);
296 	if (ret < 0)
297 		dev_err(&client->dev, "failed to set interrupt mode\n");
298 	mutex_unlock(&data->lock);
299 
300 	return ret;
301 }
302 
303 static int stk3310_read_raw(struct iio_dev *indio_dev,
304 			    struct iio_chan_spec const *chan,
305 			    int *val, int *val2, long mask)
306 {
307 	u8 reg;
308 	__be16 buf;
309 	int ret;
310 	unsigned int index;
311 	struct stk3310_data *data = iio_priv(indio_dev);
312 	struct i2c_client *client = data->client;
313 
314 	if (chan->type != IIO_LIGHT && chan->type != IIO_PROXIMITY)
315 		return -EINVAL;
316 
317 	switch (mask) {
318 	case IIO_CHAN_INFO_RAW:
319 		if (chan->type == IIO_LIGHT)
320 			reg = STK3310_REG_ALS_DATA_MSB;
321 		else
322 			reg = STK3310_REG_PS_DATA_MSB;
323 
324 		mutex_lock(&data->lock);
325 		ret = regmap_bulk_read(data->regmap, reg, &buf, 2);
326 		if (ret < 0) {
327 			dev_err(&client->dev, "register read failed\n");
328 			mutex_unlock(&data->lock);
329 			return ret;
330 		}
331 		*val = be16_to_cpu(buf);
332 		mutex_unlock(&data->lock);
333 		return IIO_VAL_INT;
334 	case IIO_CHAN_INFO_INT_TIME:
335 		if (chan->type == IIO_LIGHT)
336 			ret = regmap_field_read(data->reg_als_it, &index);
337 		else
338 			ret = regmap_field_read(data->reg_ps_it, &index);
339 		if (ret < 0)
340 			return ret;
341 
342 		*val = stk3310_it_table[index][0];
343 		*val2 = stk3310_it_table[index][1];
344 		return IIO_VAL_INT_PLUS_MICRO;
345 	case IIO_CHAN_INFO_SCALE:
346 		if (chan->type == IIO_LIGHT)
347 			ret = regmap_field_read(data->reg_als_gain, &index);
348 		else
349 			ret = regmap_field_read(data->reg_ps_gain, &index);
350 		if (ret < 0)
351 			return ret;
352 
353 		*val = stk3310_scale_table[index][0];
354 		*val2 = stk3310_scale_table[index][1];
355 		return IIO_VAL_INT_PLUS_MICRO;
356 	}
357 
358 	return -EINVAL;
359 }
360 
361 static int stk3310_write_raw(struct iio_dev *indio_dev,
362 			     struct iio_chan_spec const *chan,
363 			     int val, int val2, long mask)
364 {
365 	int ret;
366 	int index;
367 	struct stk3310_data *data = iio_priv(indio_dev);
368 
369 	if (chan->type != IIO_LIGHT && chan->type != IIO_PROXIMITY)
370 		return -EINVAL;
371 
372 	switch (mask) {
373 	case IIO_CHAN_INFO_INT_TIME:
374 		index = stk3310_get_index(stk3310_it_table,
375 					  ARRAY_SIZE(stk3310_it_table),
376 					  val, val2);
377 		if (index < 0)
378 			return -EINVAL;
379 		mutex_lock(&data->lock);
380 		if (chan->type == IIO_LIGHT)
381 			ret = regmap_field_write(data->reg_als_it, index);
382 		else
383 			ret = regmap_field_write(data->reg_ps_it, index);
384 		if (ret < 0)
385 			dev_err(&data->client->dev,
386 				"sensor configuration failed\n");
387 		mutex_unlock(&data->lock);
388 		return ret;
389 
390 	case IIO_CHAN_INFO_SCALE:
391 		index = stk3310_get_index(stk3310_scale_table,
392 					  ARRAY_SIZE(stk3310_scale_table),
393 					  val, val2);
394 		if (index < 0)
395 			return -EINVAL;
396 		mutex_lock(&data->lock);
397 		if (chan->type == IIO_LIGHT)
398 			ret = regmap_field_write(data->reg_als_gain, index);
399 		else
400 			ret = regmap_field_write(data->reg_ps_gain, index);
401 		if (ret < 0)
402 			dev_err(&data->client->dev,
403 				"sensor configuration failed\n");
404 		mutex_unlock(&data->lock);
405 		return ret;
406 	}
407 
408 	return -EINVAL;
409 }
410 
411 static const struct iio_info stk3310_info = {
412 	.driver_module		= THIS_MODULE,
413 	.read_raw		= stk3310_read_raw,
414 	.write_raw		= stk3310_write_raw,
415 	.attrs			= &stk3310_attribute_group,
416 	.read_event_value	= stk3310_read_event,
417 	.write_event_value	= stk3310_write_event,
418 	.read_event_config	= stk3310_read_event_config,
419 	.write_event_config	= stk3310_write_event_config,
420 };
421 
422 static int stk3310_set_state(struct stk3310_data *data, u8 state)
423 {
424 	int ret;
425 	struct i2c_client *client = data->client;
426 
427 	/* 3-bit state; 0b100 is not supported. */
428 	if (state > 7 || state == 4)
429 		return -EINVAL;
430 
431 	mutex_lock(&data->lock);
432 	ret = regmap_field_write(data->reg_state, state);
433 	if (ret < 0) {
434 		dev_err(&client->dev, "failed to change sensor state\n");
435 	} else if (state != STK3310_STATE_STANDBY) {
436 		/* Don't reset the 'enabled' flags if we're going in standby */
437 		data->ps_enabled  = !!(state & STK3310_STATE_EN_PS);
438 		data->als_enabled = !!(state & STK3310_STATE_EN_ALS);
439 	}
440 	mutex_unlock(&data->lock);
441 
442 	return ret;
443 }
444 
445 static int stk3310_init(struct iio_dev *indio_dev)
446 {
447 	int ret;
448 	int chipid;
449 	u8 state;
450 	struct stk3310_data *data = iio_priv(indio_dev);
451 	struct i2c_client *client = data->client;
452 
453 	ret = regmap_read(data->regmap, STK3310_REG_ID, &chipid);
454 	if (ret < 0)
455 		return ret;
456 
457 	if (chipid != STK3310_CHIP_ID_VAL &&
458 	    chipid != STK3311_CHIP_ID_VAL) {
459 		dev_err(&client->dev, "invalid chip id: 0x%x\n", chipid);
460 		return -ENODEV;
461 	}
462 
463 	state = STK3310_STATE_EN_ALS | STK3310_STATE_EN_PS;
464 	ret = stk3310_set_state(data, state);
465 	if (ret < 0) {
466 		dev_err(&client->dev, "failed to enable sensor");
467 		return ret;
468 	}
469 
470 	/* Enable PS interrupts */
471 	ret = regmap_field_write(data->reg_int_ps, STK3310_PSINT_EN);
472 	if (ret < 0)
473 		dev_err(&client->dev, "failed to enable interrupts!\n");
474 
475 	return ret;
476 }
477 
478 static bool stk3310_is_volatile_reg(struct device *dev, unsigned int reg)
479 {
480 	switch (reg) {
481 	case STK3310_REG_ALS_DATA_MSB:
482 	case STK3310_REG_ALS_DATA_LSB:
483 	case STK3310_REG_PS_DATA_LSB:
484 	case STK3310_REG_PS_DATA_MSB:
485 	case STK3310_REG_FLAG:
486 		return true;
487 	default:
488 		return false;
489 	}
490 }
491 
492 static struct regmap_config stk3310_regmap_config = {
493 	.name = STK3310_REGMAP_NAME,
494 	.reg_bits = 8,
495 	.val_bits = 8,
496 	.max_register = STK3310_MAX_REG,
497 	.cache_type = REGCACHE_RBTREE,
498 	.volatile_reg = stk3310_is_volatile_reg,
499 };
500 
501 static int stk3310_regmap_init(struct stk3310_data *data)
502 {
503 	struct regmap *regmap;
504 	struct i2c_client *client;
505 
506 	client = data->client;
507 	regmap = devm_regmap_init_i2c(client, &stk3310_regmap_config);
508 	if (IS_ERR(regmap)) {
509 		dev_err(&client->dev, "regmap initialization failed.\n");
510 		return PTR_ERR(regmap);
511 	}
512 	data->regmap = regmap;
513 
514 	STK3310_REGFIELD(state);
515 	STK3310_REGFIELD(als_gain);
516 	STK3310_REGFIELD(ps_gain);
517 	STK3310_REGFIELD(als_it);
518 	STK3310_REGFIELD(ps_it);
519 	STK3310_REGFIELD(int_ps);
520 	STK3310_REGFIELD(flag_psint);
521 	STK3310_REGFIELD(flag_nf);
522 
523 	return 0;
524 }
525 
526 static irqreturn_t stk3310_irq_handler(int irq, void *private)
527 {
528 	struct iio_dev *indio_dev = private;
529 	struct stk3310_data *data = iio_priv(indio_dev);
530 
531 	data->timestamp = iio_get_time_ns(indio_dev);
532 
533 	return IRQ_WAKE_THREAD;
534 }
535 
536 static irqreturn_t stk3310_irq_event_handler(int irq, void *private)
537 {
538 	int ret;
539 	unsigned int dir;
540 	u64 event;
541 
542 	struct iio_dev *indio_dev = private;
543 	struct stk3310_data *data = iio_priv(indio_dev);
544 
545 	/* Read FLAG_NF to figure out what threshold has been met. */
546 	mutex_lock(&data->lock);
547 	ret = regmap_field_read(data->reg_flag_nf, &dir);
548 	if (ret < 0) {
549 		dev_err(&data->client->dev, "register read failed\n");
550 		mutex_unlock(&data->lock);
551 		return ret;
552 	}
553 	event = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 1,
554 				     IIO_EV_TYPE_THRESH,
555 				     (dir ? IIO_EV_DIR_FALLING :
556 					    IIO_EV_DIR_RISING));
557 	iio_push_event(indio_dev, event, data->timestamp);
558 
559 	/* Reset the interrupt flag */
560 	ret = regmap_field_write(data->reg_flag_psint, 0);
561 	if (ret < 0)
562 		dev_err(&data->client->dev, "failed to reset interrupts\n");
563 	mutex_unlock(&data->lock);
564 
565 	return IRQ_HANDLED;
566 }
567 
568 static int stk3310_probe(struct i2c_client *client,
569 			 const struct i2c_device_id *id)
570 {
571 	int ret;
572 	struct iio_dev *indio_dev;
573 	struct stk3310_data *data;
574 
575 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
576 	if (!indio_dev) {
577 		dev_err(&client->dev, "iio allocation failed!\n");
578 		return -ENOMEM;
579 	}
580 
581 	data = iio_priv(indio_dev);
582 	data->client = client;
583 	i2c_set_clientdata(client, indio_dev);
584 	mutex_init(&data->lock);
585 
586 	ret = stk3310_regmap_init(data);
587 	if (ret < 0)
588 		return ret;
589 
590 	indio_dev->dev.parent = &client->dev;
591 	indio_dev->info = &stk3310_info;
592 	indio_dev->name = STK3310_DRIVER_NAME;
593 	indio_dev->modes = INDIO_DIRECT_MODE;
594 	indio_dev->channels = stk3310_channels;
595 	indio_dev->num_channels = ARRAY_SIZE(stk3310_channels);
596 
597 	ret = stk3310_init(indio_dev);
598 	if (ret < 0)
599 		return ret;
600 
601 	if (client->irq > 0) {
602 		ret = devm_request_threaded_irq(&client->dev, client->irq,
603 						stk3310_irq_handler,
604 						stk3310_irq_event_handler,
605 						IRQF_TRIGGER_FALLING |
606 						IRQF_ONESHOT,
607 						STK3310_EVENT, indio_dev);
608 		if (ret < 0) {
609 			dev_err(&client->dev, "request irq %d failed\n",
610 				client->irq);
611 			goto err_standby;
612 		}
613 	}
614 
615 	ret = iio_device_register(indio_dev);
616 	if (ret < 0) {
617 		dev_err(&client->dev, "device_register failed\n");
618 		goto err_standby;
619 	}
620 
621 	return 0;
622 
623 err_standby:
624 	stk3310_set_state(data, STK3310_STATE_STANDBY);
625 	return ret;
626 }
627 
628 static int stk3310_remove(struct i2c_client *client)
629 {
630 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
631 
632 	iio_device_unregister(indio_dev);
633 	return stk3310_set_state(iio_priv(indio_dev), STK3310_STATE_STANDBY);
634 }
635 
636 #ifdef CONFIG_PM_SLEEP
637 static int stk3310_suspend(struct device *dev)
638 {
639 	struct stk3310_data *data;
640 
641 	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
642 
643 	return stk3310_set_state(data, STK3310_STATE_STANDBY);
644 }
645 
646 static int stk3310_resume(struct device *dev)
647 {
648 	u8 state = 0;
649 	struct stk3310_data *data;
650 
651 	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
652 	if (data->ps_enabled)
653 		state |= STK3310_STATE_EN_PS;
654 	if (data->als_enabled)
655 		state |= STK3310_STATE_EN_ALS;
656 
657 	return stk3310_set_state(data, state);
658 }
659 
660 static SIMPLE_DEV_PM_OPS(stk3310_pm_ops, stk3310_suspend, stk3310_resume);
661 
662 #define STK3310_PM_OPS (&stk3310_pm_ops)
663 #else
664 #define STK3310_PM_OPS NULL
665 #endif
666 
667 static const struct i2c_device_id stk3310_i2c_id[] = {
668 	{"STK3310", 0},
669 	{"STK3311", 0},
670 	{}
671 };
672 MODULE_DEVICE_TABLE(i2c, stk3310_i2c_id);
673 
674 static const struct acpi_device_id stk3310_acpi_id[] = {
675 	{"STK3310", 0},
676 	{"STK3311", 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