xref: /openbmc/linux/drivers/iio/light/opt3001.c (revision 84e8d090)
1 /**
2  * opt3001.c - Texas Instruments OPT3001 Light Sensor
3  *
4  * Copyright (C) 2014 Texas Instruments Incorporated - http://www.ti.com
5  *
6  * Author: Andreas Dannenberg <dannenberg@ti.com>
7  * Based on previous work from: Felipe Balbi <balbi@ti.com>
8  *
9  * This program is free software: you can redistribute it and/or modify it
10  * under the terms of the GNU General Public License version 2 of the License
11  * as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but WITHOUT
14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16  * more details.
17  */
18 
19 #include <linux/bitops.h>
20 #include <linux/delay.h>
21 #include <linux/device.h>
22 #include <linux/i2c.h>
23 #include <linux/interrupt.h>
24 #include <linux/irq.h>
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/mutex.h>
28 #include <linux/slab.h>
29 #include <linux/types.h>
30 
31 #include <linux/iio/events.h>
32 #include <linux/iio/iio.h>
33 #include <linux/iio/sysfs.h>
34 
35 #define OPT3001_RESULT		0x00
36 #define OPT3001_CONFIGURATION	0x01
37 #define OPT3001_LOW_LIMIT	0x02
38 #define OPT3001_HIGH_LIMIT	0x03
39 #define OPT3001_MANUFACTURER_ID	0x7e
40 #define OPT3001_DEVICE_ID	0x7f
41 
42 #define OPT3001_CONFIGURATION_RN_MASK	(0xf << 12)
43 #define OPT3001_CONFIGURATION_RN_AUTO	(0xc << 12)
44 
45 #define OPT3001_CONFIGURATION_CT	BIT(11)
46 
47 #define OPT3001_CONFIGURATION_M_MASK	(3 << 9)
48 #define OPT3001_CONFIGURATION_M_SHUTDOWN (0 << 9)
49 #define OPT3001_CONFIGURATION_M_SINGLE	(1 << 9)
50 #define OPT3001_CONFIGURATION_M_CONTINUOUS (2 << 9) /* also 3 << 9 */
51 
52 #define OPT3001_CONFIGURATION_OVF	BIT(8)
53 #define OPT3001_CONFIGURATION_CRF	BIT(7)
54 #define OPT3001_CONFIGURATION_FH	BIT(6)
55 #define OPT3001_CONFIGURATION_FL	BIT(5)
56 #define OPT3001_CONFIGURATION_L		BIT(4)
57 #define OPT3001_CONFIGURATION_POL	BIT(3)
58 #define OPT3001_CONFIGURATION_ME	BIT(2)
59 
60 #define OPT3001_CONFIGURATION_FC_MASK	(3 << 0)
61 
62 /* The end-of-conversion enable is located in the low-limit register */
63 #define OPT3001_LOW_LIMIT_EOC_ENABLE	0xc000
64 
65 #define OPT3001_REG_EXPONENT(n)		((n) >> 12)
66 #define OPT3001_REG_MANTISSA(n)		((n) & 0xfff)
67 
68 #define OPT3001_INT_TIME_LONG		800000
69 #define OPT3001_INT_TIME_SHORT		100000
70 
71 /*
72  * Time to wait for conversion result to be ready. The device datasheet
73  * worst-case max value is 880ms. Add some slack to be on the safe side.
74  */
75 #define OPT3001_RESULT_READY_TIMEOUT	msecs_to_jiffies(1000)
76 
77 struct opt3001 {
78 	struct i2c_client	*client;
79 	struct device		*dev;
80 
81 	struct mutex		lock;
82 	bool			ok_to_ignore_lock;
83 	bool			result_ready;
84 	wait_queue_head_t	result_ready_queue;
85 	u16			result;
86 
87 	u32			int_time;
88 	u32			mode;
89 
90 	u16			high_thresh_mantissa;
91 	u16			low_thresh_mantissa;
92 
93 	u8			high_thresh_exp;
94 	u8			low_thresh_exp;
95 };
96 
97 struct opt3001_scale {
98 	int	val;
99 	int	val2;
100 };
101 
102 static const struct opt3001_scale opt3001_scales[] = {
103 	{
104 		.val = 40,
105 		.val2 = 950000,
106 	},
107 	{
108 		.val = 81,
109 		.val2 = 900000,
110 	},
111 	{
112 		.val = 163,
113 		.val2 = 800000,
114 	},
115 	{
116 		.val = 327,
117 		.val2 = 600000,
118 	},
119 	{
120 		.val = 655,
121 		.val2 = 200000,
122 	},
123 	{
124 		.val = 1310,
125 		.val2 = 400000,
126 	},
127 	{
128 		.val = 2620,
129 		.val2 = 800000,
130 	},
131 	{
132 		.val = 5241,
133 		.val2 = 600000,
134 	},
135 	{
136 		.val = 10483,
137 		.val2 = 200000,
138 	},
139 	{
140 		.val = 20966,
141 		.val2 = 400000,
142 	},
143 	{
144 		.val = 83865,
145 		.val2 = 600000,
146 	},
147 };
148 
149 static int opt3001_find_scale(const struct opt3001 *opt, int val,
150 		int val2, u8 *exponent)
151 {
152 	int i;
153 
154 	for (i = 0; i < ARRAY_SIZE(opt3001_scales); i++) {
155 		const struct opt3001_scale *scale = &opt3001_scales[i];
156 
157 		/*
158 		 * Combine the integer and micro parts for comparison
159 		 * purposes. Use milli lux precision to avoid 32-bit integer
160 		 * overflows.
161 		 */
162 		if ((val * 1000 + val2 / 1000) <=
163 				(scale->val * 1000 + scale->val2 / 1000)) {
164 			*exponent = i;
165 			return 0;
166 		}
167 	}
168 
169 	return -EINVAL;
170 }
171 
172 static void opt3001_to_iio_ret(struct opt3001 *opt, u8 exponent,
173 		u16 mantissa, int *val, int *val2)
174 {
175 	int lux;
176 
177 	lux = 10 * (mantissa << exponent);
178 	*val = lux / 1000;
179 	*val2 = (lux - (*val * 1000)) * 1000;
180 }
181 
182 static void opt3001_set_mode(struct opt3001 *opt, u16 *reg, u16 mode)
183 {
184 	*reg &= ~OPT3001_CONFIGURATION_M_MASK;
185 	*reg |= mode;
186 	opt->mode = mode;
187 }
188 
189 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.1 0.8");
190 
191 static struct attribute *opt3001_attributes[] = {
192 	&iio_const_attr_integration_time_available.dev_attr.attr,
193 	NULL
194 };
195 
196 static const struct attribute_group opt3001_attribute_group = {
197 	.attrs = opt3001_attributes,
198 };
199 
200 static const struct iio_event_spec opt3001_event_spec[] = {
201 	{
202 		.type = IIO_EV_TYPE_THRESH,
203 		.dir = IIO_EV_DIR_RISING,
204 		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
205 			BIT(IIO_EV_INFO_ENABLE),
206 	},
207 	{
208 		.type = IIO_EV_TYPE_THRESH,
209 		.dir = IIO_EV_DIR_FALLING,
210 		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
211 			BIT(IIO_EV_INFO_ENABLE),
212 	},
213 };
214 
215 static const struct iio_chan_spec opt3001_channels[] = {
216 	{
217 		.type = IIO_LIGHT,
218 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
219 				BIT(IIO_CHAN_INFO_INT_TIME),
220 		.event_spec = opt3001_event_spec,
221 		.num_event_specs = ARRAY_SIZE(opt3001_event_spec),
222 	},
223 	IIO_CHAN_SOFT_TIMESTAMP(1),
224 };
225 
226 static int opt3001_get_lux(struct opt3001 *opt, int *val, int *val2)
227 {
228 	int ret;
229 	u16 mantissa;
230 	u16 reg;
231 	u8 exponent;
232 	u16 value;
233 
234 	/*
235 	 * Enable the end-of-conversion interrupt mechanism. Note that doing
236 	 * so will overwrite the low-level limit value however we will restore
237 	 * this value later on.
238 	 */
239 	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_LOW_LIMIT,
240 			OPT3001_LOW_LIMIT_EOC_ENABLE);
241 	if (ret < 0) {
242 		dev_err(opt->dev, "failed to write register %02x\n",
243 				OPT3001_LOW_LIMIT);
244 		return ret;
245 	}
246 
247 	/* Reset data-ready indicator flag (will be set in the IRQ routine) */
248 	opt->result_ready = false;
249 
250 	/* Allow IRQ to access the device despite lock being set */
251 	opt->ok_to_ignore_lock = true;
252 
253 	/* Configure for single-conversion mode and start a new conversion */
254 	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
255 	if (ret < 0) {
256 		dev_err(opt->dev, "failed to read register %02x\n",
257 				OPT3001_CONFIGURATION);
258 		goto err;
259 	}
260 
261 	reg = ret;
262 	opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SINGLE);
263 
264 	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
265 			reg);
266 	if (ret < 0) {
267 		dev_err(opt->dev, "failed to write register %02x\n",
268 				OPT3001_CONFIGURATION);
269 		goto err;
270 	}
271 
272 	/* Wait for the IRQ to indicate the conversion is complete */
273 	ret = wait_event_timeout(opt->result_ready_queue, opt->result_ready,
274 			OPT3001_RESULT_READY_TIMEOUT);
275 
276 err:
277 	/* Disallow IRQ to access the device while lock is active */
278 	opt->ok_to_ignore_lock = false;
279 
280 	if (ret == 0)
281 		return -ETIMEDOUT;
282 	else if (ret < 0)
283 		return ret;
284 
285 	/*
286 	 * Disable the end-of-conversion interrupt mechanism by restoring the
287 	 * low-level limit value (clearing OPT3001_LOW_LIMIT_EOC_ENABLE). Note
288 	 * that selectively clearing those enable bits would affect the actual
289 	 * limit value due to bit-overlap and therefore can't be done.
290 	 */
291 	value = (opt->low_thresh_exp << 12) | opt->low_thresh_mantissa;
292 	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_LOW_LIMIT,
293 			value);
294 	if (ret < 0) {
295 		dev_err(opt->dev, "failed to write register %02x\n",
296 				OPT3001_LOW_LIMIT);
297 		return ret;
298 	}
299 
300 	exponent = OPT3001_REG_EXPONENT(opt->result);
301 	mantissa = OPT3001_REG_MANTISSA(opt->result);
302 
303 	opt3001_to_iio_ret(opt, exponent, mantissa, val, val2);
304 
305 	return IIO_VAL_INT_PLUS_MICRO;
306 }
307 
308 static int opt3001_get_int_time(struct opt3001 *opt, int *val, int *val2)
309 {
310 	*val = 0;
311 	*val2 = opt->int_time;
312 
313 	return IIO_VAL_INT_PLUS_MICRO;
314 }
315 
316 static int opt3001_set_int_time(struct opt3001 *opt, int time)
317 {
318 	int ret;
319 	u16 reg;
320 
321 	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
322 	if (ret < 0) {
323 		dev_err(opt->dev, "failed to read register %02x\n",
324 				OPT3001_CONFIGURATION);
325 		return ret;
326 	}
327 
328 	reg = ret;
329 
330 	switch (time) {
331 	case OPT3001_INT_TIME_SHORT:
332 		reg &= ~OPT3001_CONFIGURATION_CT;
333 		opt->int_time = OPT3001_INT_TIME_SHORT;
334 		break;
335 	case OPT3001_INT_TIME_LONG:
336 		reg |= OPT3001_CONFIGURATION_CT;
337 		opt->int_time = OPT3001_INT_TIME_LONG;
338 		break;
339 	default:
340 		return -EINVAL;
341 	}
342 
343 	return i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
344 			reg);
345 }
346 
347 static int opt3001_read_raw(struct iio_dev *iio,
348 		struct iio_chan_spec const *chan, int *val, int *val2,
349 		long mask)
350 {
351 	struct opt3001 *opt = iio_priv(iio);
352 	int ret;
353 
354 	if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
355 		return -EBUSY;
356 
357 	if (chan->type != IIO_LIGHT)
358 		return -EINVAL;
359 
360 	mutex_lock(&opt->lock);
361 
362 	switch (mask) {
363 	case IIO_CHAN_INFO_PROCESSED:
364 		ret = opt3001_get_lux(opt, val, val2);
365 		break;
366 	case IIO_CHAN_INFO_INT_TIME:
367 		ret = opt3001_get_int_time(opt, val, val2);
368 		break;
369 	default:
370 		ret = -EINVAL;
371 	}
372 
373 	mutex_unlock(&opt->lock);
374 
375 	return ret;
376 }
377 
378 static int opt3001_write_raw(struct iio_dev *iio,
379 		struct iio_chan_spec const *chan, int val, int val2,
380 		long mask)
381 {
382 	struct opt3001 *opt = iio_priv(iio);
383 	int ret;
384 
385 	if (opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
386 		return -EBUSY;
387 
388 	if (chan->type != IIO_LIGHT)
389 		return -EINVAL;
390 
391 	if (mask != IIO_CHAN_INFO_INT_TIME)
392 		return -EINVAL;
393 
394 	if (val != 0)
395 		return -EINVAL;
396 
397 	mutex_lock(&opt->lock);
398 	ret = opt3001_set_int_time(opt, val2);
399 	mutex_unlock(&opt->lock);
400 
401 	return ret;
402 }
403 
404 static int opt3001_read_event_value(struct iio_dev *iio,
405 		const struct iio_chan_spec *chan, enum iio_event_type type,
406 		enum iio_event_direction dir, enum iio_event_info info,
407 		int *val, int *val2)
408 {
409 	struct opt3001 *opt = iio_priv(iio);
410 	int ret = IIO_VAL_INT_PLUS_MICRO;
411 
412 	mutex_lock(&opt->lock);
413 
414 	switch (dir) {
415 	case IIO_EV_DIR_RISING:
416 		opt3001_to_iio_ret(opt, opt->high_thresh_exp,
417 				opt->high_thresh_mantissa, val, val2);
418 		break;
419 	case IIO_EV_DIR_FALLING:
420 		opt3001_to_iio_ret(opt, opt->low_thresh_exp,
421 				opt->low_thresh_mantissa, val, val2);
422 		break;
423 	default:
424 		ret = -EINVAL;
425 	}
426 
427 	mutex_unlock(&opt->lock);
428 
429 	return ret;
430 }
431 
432 static int opt3001_write_event_value(struct iio_dev *iio,
433 		const struct iio_chan_spec *chan, enum iio_event_type type,
434 		enum iio_event_direction dir, enum iio_event_info info,
435 		int val, int val2)
436 {
437 	struct opt3001 *opt = iio_priv(iio);
438 	int ret;
439 
440 	u16 mantissa;
441 	u16 value;
442 	u16 reg;
443 
444 	u8 exponent;
445 
446 	if (val < 0)
447 		return -EINVAL;
448 
449 	mutex_lock(&opt->lock);
450 
451 	ret = opt3001_find_scale(opt, val, val2, &exponent);
452 	if (ret < 0) {
453 		dev_err(opt->dev, "can't find scale for %d.%06u\n", val, val2);
454 		goto err;
455 	}
456 
457 	mantissa = (((val * 1000) + (val2 / 1000)) / 10) >> exponent;
458 	value = (exponent << 12) | mantissa;
459 
460 	switch (dir) {
461 	case IIO_EV_DIR_RISING:
462 		reg = OPT3001_HIGH_LIMIT;
463 		opt->high_thresh_mantissa = mantissa;
464 		opt->high_thresh_exp = exponent;
465 		break;
466 	case IIO_EV_DIR_FALLING:
467 		reg = OPT3001_LOW_LIMIT;
468 		opt->low_thresh_mantissa = mantissa;
469 		opt->low_thresh_exp = exponent;
470 		break;
471 	default:
472 		ret = -EINVAL;
473 		goto err;
474 	}
475 
476 	ret = i2c_smbus_write_word_swapped(opt->client, reg, value);
477 	if (ret < 0) {
478 		dev_err(opt->dev, "failed to write register %02x\n", reg);
479 		goto err;
480 	}
481 
482 err:
483 	mutex_unlock(&opt->lock);
484 
485 	return ret;
486 }
487 
488 static int opt3001_read_event_config(struct iio_dev *iio,
489 		const struct iio_chan_spec *chan, enum iio_event_type type,
490 		enum iio_event_direction dir)
491 {
492 	struct opt3001 *opt = iio_priv(iio);
493 
494 	return opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS;
495 }
496 
497 static int opt3001_write_event_config(struct iio_dev *iio,
498 		const struct iio_chan_spec *chan, enum iio_event_type type,
499 		enum iio_event_direction dir, int state)
500 {
501 	struct opt3001 *opt = iio_priv(iio);
502 	int ret;
503 	u16 mode;
504 	u16 reg;
505 
506 	if (state && opt->mode == OPT3001_CONFIGURATION_M_CONTINUOUS)
507 		return 0;
508 
509 	if (!state && opt->mode == OPT3001_CONFIGURATION_M_SHUTDOWN)
510 		return 0;
511 
512 	mutex_lock(&opt->lock);
513 
514 	mode = state ? OPT3001_CONFIGURATION_M_CONTINUOUS
515 		: OPT3001_CONFIGURATION_M_SHUTDOWN;
516 
517 	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
518 	if (ret < 0) {
519 		dev_err(opt->dev, "failed to read register %02x\n",
520 				OPT3001_CONFIGURATION);
521 		goto err;
522 	}
523 
524 	reg = ret;
525 	opt3001_set_mode(opt, &reg, mode);
526 
527 	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
528 			reg);
529 	if (ret < 0) {
530 		dev_err(opt->dev, "failed to write register %02x\n",
531 				OPT3001_CONFIGURATION);
532 		goto err;
533 	}
534 
535 err:
536 	mutex_unlock(&opt->lock);
537 
538 	return ret;
539 }
540 
541 static const struct iio_info opt3001_info = {
542 	.driver_module = THIS_MODULE,
543 	.attrs = &opt3001_attribute_group,
544 	.read_raw = opt3001_read_raw,
545 	.write_raw = opt3001_write_raw,
546 	.read_event_value = opt3001_read_event_value,
547 	.write_event_value = opt3001_write_event_value,
548 	.read_event_config = opt3001_read_event_config,
549 	.write_event_config = opt3001_write_event_config,
550 };
551 
552 static int opt3001_read_id(struct opt3001 *opt)
553 {
554 	char manufacturer[2];
555 	u16 device_id;
556 	int ret;
557 
558 	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_MANUFACTURER_ID);
559 	if (ret < 0) {
560 		dev_err(opt->dev, "failed to read register %02x\n",
561 				OPT3001_MANUFACTURER_ID);
562 		return ret;
563 	}
564 
565 	manufacturer[0] = ret >> 8;
566 	manufacturer[1] = ret & 0xff;
567 
568 	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_DEVICE_ID);
569 	if (ret < 0) {
570 		dev_err(opt->dev, "failed to read register %02x\n",
571 				OPT3001_DEVICE_ID);
572 		return ret;
573 	}
574 
575 	device_id = ret;
576 
577 	dev_info(opt->dev, "Found %c%c OPT%04x\n", manufacturer[0],
578 			manufacturer[1], device_id);
579 
580 	return 0;
581 }
582 
583 static int opt3001_configure(struct opt3001 *opt)
584 {
585 	int ret;
586 	u16 reg;
587 
588 	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
589 	if (ret < 0) {
590 		dev_err(opt->dev, "failed to read register %02x\n",
591 				OPT3001_CONFIGURATION);
592 		return ret;
593 	}
594 
595 	reg = ret;
596 
597 	/* Enable automatic full-scale setting mode */
598 	reg &= ~OPT3001_CONFIGURATION_RN_MASK;
599 	reg |= OPT3001_CONFIGURATION_RN_AUTO;
600 
601 	/* Reflect status of the device's integration time setting */
602 	if (reg & OPT3001_CONFIGURATION_CT)
603 		opt->int_time = OPT3001_INT_TIME_LONG;
604 	else
605 		opt->int_time = OPT3001_INT_TIME_SHORT;
606 
607 	/* Ensure device is in shutdown initially */
608 	opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SHUTDOWN);
609 
610 	/* Configure for latched window-style comparison operation */
611 	reg |= OPT3001_CONFIGURATION_L;
612 	reg &= ~OPT3001_CONFIGURATION_POL;
613 	reg &= ~OPT3001_CONFIGURATION_ME;
614 	reg &= ~OPT3001_CONFIGURATION_FC_MASK;
615 
616 	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
617 			reg);
618 	if (ret < 0) {
619 		dev_err(opt->dev, "failed to write register %02x\n",
620 				OPT3001_CONFIGURATION);
621 		return ret;
622 	}
623 
624 	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_LOW_LIMIT);
625 	if (ret < 0) {
626 		dev_err(opt->dev, "failed to read register %02x\n",
627 				OPT3001_LOW_LIMIT);
628 		return ret;
629 	}
630 
631 	opt->low_thresh_mantissa = OPT3001_REG_MANTISSA(ret);
632 	opt->low_thresh_exp = OPT3001_REG_EXPONENT(ret);
633 
634 	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_HIGH_LIMIT);
635 	if (ret < 0) {
636 		dev_err(opt->dev, "failed to read register %02x\n",
637 				OPT3001_HIGH_LIMIT);
638 		return ret;
639 	}
640 
641 	opt->high_thresh_mantissa = OPT3001_REG_MANTISSA(ret);
642 	opt->high_thresh_exp = OPT3001_REG_EXPONENT(ret);
643 
644 	return 0;
645 }
646 
647 static irqreturn_t opt3001_irq(int irq, void *_iio)
648 {
649 	struct iio_dev *iio = _iio;
650 	struct opt3001 *opt = iio_priv(iio);
651 	int ret;
652 
653 	if (!opt->ok_to_ignore_lock)
654 		mutex_lock(&opt->lock);
655 
656 	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
657 	if (ret < 0) {
658 		dev_err(opt->dev, "failed to read register %02x\n",
659 				OPT3001_CONFIGURATION);
660 		goto out;
661 	}
662 
663 	if ((ret & OPT3001_CONFIGURATION_M_MASK) ==
664 			OPT3001_CONFIGURATION_M_CONTINUOUS) {
665 		if (ret & OPT3001_CONFIGURATION_FH)
666 			iio_push_event(iio,
667 					IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
668 							IIO_EV_TYPE_THRESH,
669 							IIO_EV_DIR_RISING),
670 					iio_get_time_ns());
671 		if (ret & OPT3001_CONFIGURATION_FL)
672 			iio_push_event(iio,
673 					IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
674 							IIO_EV_TYPE_THRESH,
675 							IIO_EV_DIR_FALLING),
676 					iio_get_time_ns());
677 	} else if (ret & OPT3001_CONFIGURATION_CRF) {
678 		ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_RESULT);
679 		if (ret < 0) {
680 			dev_err(opt->dev, "failed to read register %02x\n",
681 					OPT3001_RESULT);
682 			goto out;
683 		}
684 		opt->result = ret;
685 		opt->result_ready = true;
686 		wake_up(&opt->result_ready_queue);
687 	}
688 
689 out:
690 	if (!opt->ok_to_ignore_lock)
691 		mutex_unlock(&opt->lock);
692 
693 	return IRQ_HANDLED;
694 }
695 
696 static int opt3001_probe(struct i2c_client *client,
697 		const struct i2c_device_id *id)
698 {
699 	struct device *dev = &client->dev;
700 
701 	struct iio_dev *iio;
702 	struct opt3001 *opt;
703 	int irq = client->irq;
704 	int ret;
705 
706 	iio = devm_iio_device_alloc(dev, sizeof(*opt));
707 	if (!iio)
708 		return -ENOMEM;
709 
710 	opt = iio_priv(iio);
711 	opt->client = client;
712 	opt->dev = dev;
713 
714 	mutex_init(&opt->lock);
715 	init_waitqueue_head(&opt->result_ready_queue);
716 	i2c_set_clientdata(client, iio);
717 
718 	ret = opt3001_read_id(opt);
719 	if (ret)
720 		return ret;
721 
722 	ret = opt3001_configure(opt);
723 	if (ret)
724 		return ret;
725 
726 	iio->name = client->name;
727 	iio->channels = opt3001_channels;
728 	iio->num_channels = ARRAY_SIZE(opt3001_channels);
729 	iio->dev.parent = dev;
730 	iio->modes = INDIO_DIRECT_MODE;
731 	iio->info = &opt3001_info;
732 
733 	ret = devm_iio_device_register(dev, iio);
734 	if (ret) {
735 		dev_err(dev, "failed to register IIO device\n");
736 		return ret;
737 	}
738 
739 	ret = request_threaded_irq(irq, NULL, opt3001_irq,
740 			IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
741 			"opt3001", iio);
742 	if (ret) {
743 		dev_err(dev, "failed to request IRQ #%d\n", irq);
744 		return ret;
745 	}
746 
747 	return 0;
748 }
749 
750 static int opt3001_remove(struct i2c_client *client)
751 {
752 	struct iio_dev *iio = i2c_get_clientdata(client);
753 	struct opt3001 *opt = iio_priv(iio);
754 	int ret;
755 	u16 reg;
756 
757 	free_irq(client->irq, iio);
758 
759 	ret = i2c_smbus_read_word_swapped(opt->client, OPT3001_CONFIGURATION);
760 	if (ret < 0) {
761 		dev_err(opt->dev, "failed to read register %02x\n",
762 				OPT3001_CONFIGURATION);
763 		return ret;
764 	}
765 
766 	reg = ret;
767 	opt3001_set_mode(opt, &reg, OPT3001_CONFIGURATION_M_SHUTDOWN);
768 
769 	ret = i2c_smbus_write_word_swapped(opt->client, OPT3001_CONFIGURATION,
770 			reg);
771 	if (ret < 0) {
772 		dev_err(opt->dev, "failed to write register %02x\n",
773 				OPT3001_CONFIGURATION);
774 		return ret;
775 	}
776 
777 	return 0;
778 }
779 
780 static const struct i2c_device_id opt3001_id[] = {
781 	{ "opt3001", 0 },
782 	{ } /* Terminating Entry */
783 };
784 MODULE_DEVICE_TABLE(i2c, opt3001_id);
785 
786 static const struct of_device_id opt3001_of_match[] = {
787 	{ .compatible = "ti,opt3001" },
788 	{ }
789 };
790 
791 static struct i2c_driver opt3001_driver = {
792 	.probe = opt3001_probe,
793 	.remove = opt3001_remove,
794 	.id_table = opt3001_id,
795 
796 	.driver = {
797 		.name = "opt3001",
798 		.of_match_table = of_match_ptr(opt3001_of_match),
799 	},
800 };
801 
802 module_i2c_driver(opt3001_driver);
803 
804 MODULE_LICENSE("GPL v2");
805 MODULE_AUTHOR("Andreas Dannenberg <dannenberg@ti.com>");
806 MODULE_DESCRIPTION("Texas Instruments OPT3001 Light Sensor Driver");
807