summaryrefslogtreecommitdiffstats
path: root/drivers/media/i2c/as3645a.c
blob: 58d523f2648f61894ff8ed98526fff077da79e91 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
/*
 * drivers/media/i2c/as3645a.c - AS3645A and LM3555 flash controllers driver
 *
 * Copyright (C) 2008-2011 Nokia Corporation
 * Copyright (c) 2011, Intel Corporation.
 *
 * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 * TODO:
 * - Check hardware FSTROBE control when sensor driver add support for this
 *
 */

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>

#include <media/as3645a.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>

#define AS_TIMER_MS_TO_CODE(t)			(((t) - 100) / 50)
#define AS_TIMER_CODE_TO_MS(c)			(50 * (c) + 100)

/* Register definitions */

/* Read-only Design info register: Reset state: xxxx 0001 */
#define AS_DESIGN_INFO_REG			0x00
#define AS_DESIGN_INFO_FACTORY(x)		(((x) >> 4))
#define AS_DESIGN_INFO_MODEL(x)			((x) & 0x0f)

/* Read-only Version control register: Reset state: 0000 0000
 * for first engineering samples
 */
#define AS_VERSION_CONTROL_REG			0x01
#define AS_VERSION_CONTROL_RFU(x)		(((x) >> 4))
#define AS_VERSION_CONTROL_VERSION(x)		((x) & 0x0f)

/* Read / Write	(Indicator and timer register): Reset state: 0000 1111 */
#define AS_INDICATOR_AND_TIMER_REG		0x02
#define AS_INDICATOR_AND_TIMER_TIMEOUT_SHIFT	0
#define AS_INDICATOR_AND_TIMER_VREF_SHIFT	4
#define AS_INDICATOR_AND_TIMER_INDICATOR_SHIFT	6

/* Read / Write	(Current set register): Reset state: 0110 1001 */
#define AS_CURRENT_SET_REG			0x03
#define AS_CURRENT_ASSIST_LIGHT_SHIFT		0
#define AS_CURRENT_LED_DET_ON			(1 << 3)
#define AS_CURRENT_FLASH_CURRENT_SHIFT		4

/* Read / Write	(Control register): Reset state: 1011 0100 */
#define AS_CONTROL_REG				0x04
#define AS_CONTROL_MODE_SETTING_SHIFT		0
#define AS_CONTROL_STROBE_ON			(1 << 2)
#define AS_CONTROL_OUT_ON			(1 << 3)
#define AS_CONTROL_EXT_TORCH_ON			(1 << 4)
#define AS_CONTROL_STROBE_TYPE_EDGE		(0 << 5)
#define AS_CONTROL_STROBE_TYPE_LEVEL		(1 << 5)
#define AS_CONTROL_COIL_PEAK_SHIFT		6

/* Read only (D3 is read / write) (Fault and info): Reset state: 0000 x000 */
#define AS_FAULT_INFO_REG			0x05
#define AS_FAULT_INFO_INDUCTOR_PEAK_LIMIT	(1 << 1)
#define AS_FAULT_INFO_INDICATOR_LED		(1 << 2)
#define AS_FAULT_INFO_LED_AMOUNT		(1 << 3)
#define AS_FAULT_INFO_TIMEOUT			(1 << 4)
#define AS_FAULT_INFO_OVER_TEMPERATURE		(1 << 5)
#define AS_FAULT_INFO_SHORT_CIRCUIT		(1 << 6)
#define AS_FAULT_INFO_OVER_VOLTAGE		(1 << 7)

/* Boost register */
#define AS_BOOST_REG				0x0d
#define AS_BOOST_CURRENT_DISABLE		(0 << 0)
#define AS_BOOST_CURRENT_ENABLE			(1 << 0)

/* Password register is used to unlock boost register writing */
#define AS_PASSWORD_REG				0x0f
#define AS_PASSWORD_UNLOCK_VALUE		0x55

enum as_mode {
	AS_MODE_EXT_TORCH = 0 << AS_CONTROL_MODE_SETTING_SHIFT,
	AS_MODE_INDICATOR = 1 << AS_CONTROL_MODE_SETTING_SHIFT,
	AS_MODE_ASSIST = 2 << AS_CONTROL_MODE_SETTING_SHIFT,
	AS_MODE_FLASH = 3 << AS_CONTROL_MODE_SETTING_SHIFT,
};

/*
 * struct as3645a
 *
 * @subdev:		V4L2 subdev
 * @pdata:		Flash platform data
 * @power_lock:		Protects power_count
 * @power_count:	Power reference count
 * @led_mode:		V4L2 flash LED mode
 * @timeout:		Flash timeout in microseconds
 * @flash_current:	Flash current (0=200mA ... 15=500mA). Maximum
 *			values are 400mA for two LEDs and 500mA for one LED.
 * @assist_current:	Torch/Assist light current (0=20mA, 1=40mA ... 7=160mA)
 * @indicator_current:	Indicator LED current (0=0mA, 1=2.5mA ... 4=10mA)
 * @strobe_source:	Flash strobe source (software or external)
 */
struct as3645a {
	struct v4l2_subdev subdev;
	const struct as3645a_platform_data *pdata;

	struct mutex power_lock;
	int power_count;

	/* Controls */
	struct v4l2_ctrl_handler ctrls;

	enum v4l2_flash_led_mode led_mode;
	unsigned int timeout;
	u8 flash_current;
	u8 assist_current;
	u8 indicator_current;
	enum v4l2_flash_strobe_source strobe_source;
};

#define to_as3645a(sd) container_of(sd, struct as3645a, subdev)

/* Return negative errno else zero on success */
static int as3645a_write(struct as3645a *flash, u8 addr, u8 val)
{
	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
	int rval;

	rval = i2c_smbus_write_byte_data(client, addr, val);

	dev_dbg(&client->dev, "Write Addr:%02X Val:%02X %s\n", addr, val,
		rval < 0 ? "fail" : "ok");

	return rval;
}

/* Return negative errno else a data byte received from the device. */
static int as3645a_read(struct as3645a *flash, u8 addr)
{
	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
	int rval;

	rval = i2c_smbus_read_byte_data(client, addr);

	dev_dbg(&client->dev, "Read Addr:%02X Val:%02X %s\n", addr, rval,
		rval < 0 ? "fail" : "ok");

	return rval;
}

/* -----------------------------------------------------------------------------
 * Hardware configuration and trigger
 */

/*
 * as3645a_set_config - Set flash configuration registers
 * @flash: The flash
 *
 * Configure the hardware with flash, assist and indicator currents, as well as
 * flash timeout.
 *
 * Return 0 on success, or a negative error code if an I2C communication error
 * occurred.
 */
static int as3645a_set_config(struct as3645a *flash)
{
	int ret;
	u8 val;

	val = (flash->flash_current << AS_CURRENT_FLASH_CURRENT_SHIFT)
	    | (flash->assist_current << AS_CURRENT_ASSIST_LIGHT_SHIFT)
	    | AS_CURRENT_LED_DET_ON;

	ret = as3645a_write(flash, AS_CURRENT_SET_REG, val);
	if (ret < 0)
		return ret;

	val = AS_TIMER_MS_TO_CODE(flash->timeout / 1000)
		    << AS_INDICATOR_AND_TIMER_TIMEOUT_SHIFT;

	val |= (flash->pdata->vref << AS_INDICATOR_AND_TIMER_VREF_SHIFT)
	    |  ((flash->indicator_current ? flash->indicator_current - 1 : 0)
		 << AS_INDICATOR_AND_TIMER_INDICATOR_SHIFT);

	return as3645a_write(flash, AS_INDICATOR_AND_TIMER_REG, val);
}

/*
 * as3645a_set_control - Set flash control register
 * @flash: The flash
 * @mode: Desired output mode
 * @on: Desired output state
 *
 * Configure the hardware with output mode and state.
 *
 * Return 0 on success, or a negative error code if an I2C communication error
 * occurred.
 */
static int
as3645a_set_control(struct as3645a *flash, enum as_mode mode, bool on)
{
	u8 reg;

	/* Configure output parameters and operation mode. */
	reg = (flash->pdata->peak << AS_CONTROL_COIL_PEAK_SHIFT)
	    | (on ? AS_CONTROL_OUT_ON : 0)
	    | mode;

	if (flash->led_mode == V4L2_FLASH_LED_MODE_FLASH &&
	    flash->strobe_source == V4L2_FLASH_STROBE_SOURCE_EXTERNAL) {
		reg |= AS_CONTROL_STROBE_TYPE_LEVEL
		    |  AS_CONTROL_STROBE_ON;
	}

	return as3645a_write(flash, AS_CONTROL_REG, reg);
}

/*
 * as3645a_set_output - Configure output and operation mode
 * @flash: Flash controller
 * @strobe: Strobe the flash (only valid in flash mode)
 *
 * Turn the LEDs output on/off and set the operation mode based on the current
 * parameters.
 *
 * The AS3645A can't control the indicator LED independently of the flash/torch
 * LED. If the flash controller is in V4L2_FLASH_LED_MODE_NONE mode, set the
 * chip to indicator mode. Otherwise set it to assist light (torch) or flash
 * mode.
 *
 * In indicator and assist modes, turn the output on/off based on the indicator
 * and torch currents. In software strobe flash mode, turn the output on/off
 * based on the strobe parameter.
 */
static int as3645a_set_output(struct as3645a *flash, bool strobe)
{
	enum as_mode mode;
	bool on;

	switch (flash->led_mode) {
	case V4L2_FLASH_LED_MODE_NONE:
		on = flash->indicator_current != 0;
		mode = AS_MODE_INDICATOR;
		break;
	case V4L2_FLASH_LED_MODE_TORCH:
		on = true;
		mode = AS_MODE_ASSIST;
		break;
	case V4L2_FLASH_LED_MODE_FLASH:
		on = strobe;
		mode = AS_MODE_FLASH;
		break;
	default:
		BUG();
	}

	/* Configure output parameters and operation mode. */
	return as3645a_set_control(flash, mode, on);
}

/* -----------------------------------------------------------------------------
 * V4L2 controls
 */

static int as3645a_is_active(struct as3645a *flash)
{
	int ret;

	ret = as3645a_read(flash, AS_CONTROL_REG);
	return ret < 0 ? ret : !!(ret & AS_CONTROL_OUT_ON);
}

static int as3645a_read_fault(struct as3645a *flash)
{
	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
	int rval;

	/* NOTE: reading register clear fault status */
	rval = as3645a_read(flash, AS_FAULT_INFO_REG);
	if (rval < 0)
		return rval;

	if (rval & AS_FAULT_INFO_INDUCTOR_PEAK_LIMIT)
		dev_dbg(&client->dev, "Inductor Peak limit fault\n");

	if (rval & AS_FAULT_INFO_INDICATOR_LED)
		dev_dbg(&client->dev, "Indicator LED fault: "
			"Short circuit or open loop\n");

	dev_dbg(&client->dev, "%u connected LEDs\n",
		rval & AS_FAULT_INFO_LED_AMOUNT ? 2 : 1);

	if (rval & AS_FAULT_INFO_TIMEOUT)
		dev_dbg(&client->dev, "Timeout fault\n");

	if (rval & AS_FAULT_INFO_OVER_TEMPERATURE)
		dev_dbg(&client->dev, "Over temperature fault\n");

	if (rval & AS_FAULT_INFO_SHORT_CIRCUIT)
		dev_dbg(&client->dev, "Short circuit fault\n");

	if (rval & AS_FAULT_INFO_OVER_VOLTAGE)
		dev_dbg(&client->dev, "Over voltage fault: "
			"Indicates missing capacitor or open connection\n");

	return rval;
}

static int as3645a_get_ctrl(struct v4l2_ctrl *ctrl)
{
	struct as3645a *flash =
		container_of(ctrl->handler, struct as3645a, ctrls);
	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
	int value;

	switch (ctrl->id) {
	case V4L2_CID_FLASH_FAULT:
		value = as3645a_read_fault(flash);
		if (value < 0)
			return value;

		ctrl->cur.val = 0;
		if (value & AS_FAULT_INFO_SHORT_CIRCUIT)
			ctrl->cur.val |= V4L2_FLASH_FAULT_SHORT_CIRCUIT;
		if (value & AS_FAULT_INFO_OVER_TEMPERATURE)
			ctrl->cur.val |= V4L2_FLASH_FAULT_OVER_TEMPERATURE;
		if (value & AS_FAULT_INFO_TIMEOUT)
			ctrl->cur.val |= V4L2_FLASH_FAULT_TIMEOUT;
		if (value & AS_FAULT_INFO_OVER_VOLTAGE)
			ctrl->cur.val |= V4L2_FLASH_FAULT_OVER_VOLTAGE;
		if (value & AS_FAULT_INFO_INDUCTOR_PEAK_LIMIT)
			ctrl->cur.val |= V4L2_FLASH_FAULT_OVER_CURRENT;
		if (value & AS_FAULT_INFO_INDICATOR_LED)
			ctrl->cur.val |= V4L2_FLASH_FAULT_INDICATOR;
		break;

	case V4L2_CID_FLASH_STROBE_STATUS:
		if (flash->led_mode != V4L2_FLASH_LED_MODE_FLASH) {
			ctrl->cur.val = 0;
			break;
		}

		value = as3645a_is_active(flash);
		if (value < 0)
			return value;

		ctrl->cur.val = value;
		break;
	}

	dev_dbg(&client->dev, "G_CTRL %08x:%d\n", ctrl->id, ctrl->cur.val);

	return 0;
}

static int as3645a_set_ctrl(struct v4l2_ctrl *ctrl)
{
	struct as3645a *flash =
		container_of(ctrl->handler, struct as3645a, ctrls);
	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
	int ret;

	dev_dbg(&client->dev, "S_CTRL %08x:%d\n", ctrl->id, ctrl->val);

	/* If a control that doesn't apply to the current mode is modified,
	 * we store the value and return immediately. The setting will be
	 * applied when the LED mode is changed. Otherwise we apply the setting
	 * immediately.
	 */

	switch (ctrl->id) {
	case V4L2_CID_FLASH_LED_MODE:
		if (flash->indicator_current)
			return -EBUSY;

		ret = as3645a_set_config(flash);
		if (ret < 0)
			return ret;

		flash->led_mode = ctrl->val;
		return as3645a_set_output(flash, false);

	case V4L2_CID_FLASH_STROBE_SOURCE:
		flash->strobe_source = ctrl->val;

		/* Applies to flash mode only. */
		if (flash->led_mode != V4L2_FLASH_LED_MODE_FLASH)
			break;

		return as3645a_set_output(flash, false);

	case V4L2_CID_FLASH_STROBE:
		if (flash->led_mode != V4L2_FLASH_LED_MODE_FLASH)
			return -EBUSY;

		return as3645a_set_output(flash, true);

	case V4L2_CID_FLASH_STROBE_STOP:
		if (flash->led_mode != V4L2_FLASH_LED_MODE_FLASH)
			return -EBUSY;

		return as3645a_set_output(flash, false);

	case V4L2_CID_FLASH_TIMEOUT:
		flash->timeout = ctrl->val;

		/* Applies to flash mode only. */
		if (flash->led_mode != V4L2_FLASH_LED_MODE_FLASH)
			break;

		return as3645a_set_config(flash);

	case V4L2_CID_FLASH_INTENSITY:
		flash->flash_current = (ctrl->val - AS3645A_FLASH_INTENSITY_MIN)
				     / AS3645A_FLASH_INTENSITY_STEP;

		/* Applies to flash mode only. */
		if (flash->led_mode != V4L2_FLASH_LED_MODE_FLASH)
			break;

		return as3645a_set_config(flash);

	case V4L2_CID_FLASH_TORCH_INTENSITY:
		flash->assist_current =
			(ctrl->val - AS3645A_TORCH_INTENSITY_MIN)
			/ AS3645A_TORCH_INTENSITY_STEP;

		/* Applies to torch mode only. */
		if (flash->led_mode != V4L2_FLASH_LED_MODE_TORCH)
			break;

		return as3645a_set_config(flash);

	case V4L2_CID_FLASH_INDICATOR_INTENSITY:
		if (flash->led_mode != V4L2_FLASH_LED_MODE_NONE)
			return -EBUSY;

		flash->indicator_current =
			(ctrl->val - AS3645A_INDICATOR_INTENSITY_MIN)
			/ AS3645A_INDICATOR_INTENSITY_STEP;

		ret = as3645a_set_config(flash);
		if (ret < 0)
			return ret;

		if ((ctrl->val == 0) == (ctrl->cur.val == 0))
			break;

		return as3645a_set_output(flash, false);
	}

	return 0;
}

static const struct v4l2_ctrl_ops as3645a_ctrl_ops = {
	.g_volatile_ctrl = as3645a_get_ctrl,
	.s_ctrl = as3645a_set_ctrl,
};

/* -----------------------------------------------------------------------------
 * V4L2 subdev core operations
 */

/* Put device into know state. */
static int as3645a_setup(struct as3645a *flash)
{
	struct i2c_client *client = v4l2_get_subdevdata(&flash->subdev);
	int ret;

	/* clear errors */
	ret = as3645a_read(flash, AS_FAULT_INFO_REG);
	if (ret < 0)
		return ret;

	dev_dbg(&client->dev, "Fault info: %02x\n", ret);

	ret = as3645a_set_config(flash);
	if (ret < 0)
		return ret;

	ret = as3645a_set_output(flash, false);
	if (ret < 0)
		return ret;

	/* read status */
	ret = as3645a_read_fault(flash);
	if (ret < 0)
		return ret;

	dev_dbg(&client->dev, "AS_INDICATOR_AND_TIMER_REG: %02x\n",
		as3645a_read(flash, AS_INDICATOR_AND_TIMER_REG));
	dev_dbg(&client->dev, "AS_CURRENT_SET_REG: %02x\n",
		as3645a_read(flash, AS_CURRENT_SET_REG));
	dev_dbg(&client->dev, "AS_CONTROL_REG: %02x\n",
		as3645a_read(flash, AS_CONTROL_REG));

	return ret & ~AS_FAULT_INFO_LED_AMOUNT ? -EIO : 0;
}

static int __as3645a_set_power(struct as3645a *flash, int on)
{
	int ret;

	if (!on)
		as3645a_set_control(flash, AS_MODE_EXT_TORCH, false);

	if (flash->pdata->set_power) {
		ret = flash->pdata->set_power(&flash->subdev, on);
		if (ret < 0)
			return ret;
	}

	if (!on)
		return 0;

	ret = as3645a_setup(flash);
	if (ret < 0) {
		if (flash->pdata->set_power)
			flash->pdata->set_power(&flash->subdev, 0);
	}

	return ret;
}

static int as3645a_set_power(struct v4l2_subdev *sd, int on)
{
	struct as3645a *flash = to_as3645a(sd);
	int ret = 0;

	mutex_lock(&flash->power_lock);

	if (flash->power_count == !on) {
		ret = __as3645a_set_power(flash, !!on);
		if (ret < 0)
			goto done;
	}

	flash->power_count += on ? 1 : -1;
	WARN_ON(flash->power_count < 0);

done:
	mutex_unlock(&flash->power_lock);
	return ret;
}

static int as3645a_registered(struct v4l2_subdev *sd)
{
	struct as3645a *flash = to_as3645a(sd);
	struct i2c_client *client = v4l2_get_subdevdata(sd);
	int rval, man, model, rfu, version;
	const char *vendor;

	/* Power up the flash driver and read manufacturer ID, model ID, RFU
	 * and version.
	 */
	rval = as3645a_set_power(&flash->subdev, 1);
	if (rval < 0)
		return rval;

	rval = as3645a_read(flash, AS_DESIGN_INFO_REG);
	if (rval < 0)
		goto power_off;

	man = AS_DESIGN_INFO_FACTORY(rval);
	model = AS_DESIGN_INFO_MODEL(rval);

	rval = as3645a_read(flash, AS_VERSION_CONTROL_REG);
	if (rval < 0)
		goto power_off;

	rfu = AS_VERSION_CONTROL_RFU(rval);
	version = AS_VERSION_CONTROL_VERSION(rval);

	/* Verify the chip model and version. */
	if (model != 0x01 || rfu != 0x00) {
		dev_err(&client->dev, "AS3645A not detected "
			"(model %d rfu %d)\n", model, rfu);
		rval = -ENODEV;
		goto power_off;
	}

	switch (man) {
	case 1:
		vendor = "AMS, Austria Micro Systems";
		break;
	case 2:
		vendor = "ADI, Analog Devices Inc.";
		break;
	case 3:
		vendor = "NSC, National Semiconductor";
		break;
	case 4:
		vendor = "NXP";
		break;
	case 5:
		vendor = "TI, Texas Instrument";
		break;
	default:
		vendor = "Unknown";
	}

	dev_info(&client->dev, "Chip vendor: %s (%d) Version: %d\n", vendor,
		 man, version);

	rval = as3645a_write(flash, AS_PASSWORD_REG, AS_PASSWORD_UNLOCK_VALUE);
	if (rval < 0)
		goto power_off;

	rval = as3645a_write(flash, AS_BOOST_REG, AS_BOOST_CURRENT_DISABLE);
	if (rval < 0)
		goto power_off;

	/* Setup default values. This makes sure that the chip is in a known
	 * state, in case the power rail can't be controlled.
	 */
	rval = as3645a_setup(flash);

power_off:
	as3645a_set_power(&flash->subdev, 0);

	return rval;
}

static int as3645a_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
{
	return as3645a_set_power(sd, 1);
}

static int as3645a_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
{
	return as3645a_set_power(sd, 0);
}

static const struct v4l2_subdev_core_ops as3645a_core_ops = {
	.s_power		= as3645a_set_power,
};

static const struct v4l2_subdev_ops as3645a_ops = {
	.core = &as3645a_core_ops,
};

static const struct v4l2_subdev_internal_ops as3645a_internal_ops = {
	.registered = as3645a_registered,
	.open = as3645a_open,
	.close = as3645a_close,
};

/* -----------------------------------------------------------------------------
 *  I2C driver
 */
#ifdef CONFIG_PM

static int as3645a_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
	struct as3645a *flash = to_as3645a(subdev);
	int rval;

	if (flash->power_count == 0)
		return 0;

	rval = __as3645a_set_power(flash, 0);

	dev_dbg(&client->dev, "Suspend %s\n", rval < 0 ? "failed" : "ok");

	return rval;
}

static int as3645a_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
	struct as3645a *flash = to_as3645a(subdev);
	int rval;

	if (flash->power_count == 0)
		return 0;

	rval = __as3645a_set_power(flash, 1);

	dev_dbg(&client->dev, "Resume %s\n", rval < 0 ? "fail" : "ok");

	return rval;
}

#else

#define as3645a_suspend	NULL
#define as3645a_resume	NULL

#endif /* CONFIG_PM */

/*
 * as3645a_init_controls - Create controls
 * @flash: The flash
 *
 * The number of LEDs reported in platform data is used to compute default
 * limits. Parameters passed through platform data can override those limits.
 */
static int as3645a_init_controls(struct as3645a *flash)
{
	const struct as3645a_platform_data *pdata = flash->pdata;
	struct v4l2_ctrl *ctrl;
	int maximum;

	v4l2_ctrl_handler_init(&flash->ctrls, 10);

	/* V4L2_CID_FLASH_LED_MODE */
	v4l2_ctrl_new_std_menu(&flash->ctrls, &as3645a_ctrl_ops,
			       V4L2_CID_FLASH_LED_MODE, 2, ~7,
			       V4L2_FLASH_LED_MODE_NONE);

	/* V4L2_CID_FLASH_STROBE_SOURCE */
	v4l2_ctrl_new_std_menu(&flash->ctrls, &as3645a_ctrl_ops,
			       V4L2_CID_FLASH_STROBE_SOURCE,
			       pdata->ext_strobe ? 1 : 0,
			       pdata->ext_strobe ? ~3 : ~1,
			       V4L2_FLASH_STROBE_SOURCE_SOFTWARE);

	flash->strobe_source = V4L2_FLASH_STROBE_SOURCE_SOFTWARE;

	/* V4L2_CID_FLASH_STROBE */
	v4l2_ctrl_new_std(&flash->ctrls, &as3645a_ctrl_ops,
			  V4L2_CID_FLASH_STROBE, 0, 0, 0, 0);

	/* V4L2_CID_FLASH_STROBE_STOP */
	v4l2_ctrl_new_std(&flash->ctrls, &as3645a_ctrl_ops,
			  V4L2_CID_FLASH_STROBE_STOP, 0, 0, 0, 0);

	/* V4L2_CID_FLASH_STROBE_STATUS */
	ctrl = v4l2_ctrl_new_std(&flash->ctrls, &as3645a_ctrl_ops,
				 V4L2_CID_FLASH_STROBE_STATUS, 0, 1, 1, 1);
	if (ctrl != NULL)
		ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;

	/* V4L2_CID_FLASH_TIMEOUT */
	maximum = pdata->timeout_max;

	v4l2_ctrl_new_std(&flash->ctrls, &as3645a_ctrl_ops,
			  V4L2_CID_FLASH_TIMEOUT, AS3645A_FLASH_TIMEOUT_MIN,
			  maximum, AS3645A_FLASH_TIMEOUT_STEP, maximum);

	flash->timeout = maximum;

	/* V4L2_CID_FLASH_INTENSITY */
	maximum = pdata->flash_max_current;

	v4l2_ctrl_new_std(&flash->ctrls, &as3645a_ctrl_ops,
			  V4L2_CID_FLASH_INTENSITY, AS3645A_FLASH_INTENSITY_MIN,
			  maximum, AS3645A_FLASH_INTENSITY_STEP, maximum);

	flash->flash_current = (maximum - AS3645A_FLASH_INTENSITY_MIN)
			     / AS3645A_FLASH_INTENSITY_STEP;

	/* V4L2_CID_FLASH_TORCH_INTENSITY */
	maximum = pdata->torch_max_current;

	v4l2_ctrl_new_std(&flash->ctrls, &as3645a_ctrl_ops,
			  V4L2_CID_FLASH_TORCH_INTENSITY,
			  AS3645A_TORCH_INTENSITY_MIN, maximum,
			  AS3645A_TORCH_INTENSITY_STEP,
			  AS3645A_TORCH_INTENSITY_MIN);

	flash->assist_current = 0;

	/* V4L2_CID_FLASH_INDICATOR_INTENSITY */
	v4l2_ctrl_new_std(&flash->ctrls, &as3645a_ctrl_ops,
			  V4L2_CID_FLASH_INDICATOR_INTENSITY,
			  AS3645A_INDICATOR_INTENSITY_MIN,
			  AS3645A_INDICATOR_INTENSITY_MAX,
			  AS3645A_INDICATOR_INTENSITY_STEP,
			  AS3645A_INDICATOR_INTENSITY_MIN);

	flash->indicator_current = 0;

	/* V4L2_CID_FLASH_FAULT */
	ctrl = v4l2_ctrl_new_std(&flash->ctrls, &as3645a_ctrl_ops,
				 V4L2_CID_FLASH_FAULT, 0,
				 V4L2_FLASH_FAULT_OVER_VOLTAGE |
				 V4L2_FLASH_FAULT_TIMEOUT |
				 V4L2_FLASH_FAULT_OVER_TEMPERATURE |
				 V4L2_FLASH_FAULT_SHORT_CIRCUIT, 0, 0);
	if (ctrl != NULL)
		ctrl->flags |= V4L2_CTRL_FLAG_VOLATILE;

	flash->subdev.ctrl_handler = &flash->ctrls;

	return flash->ctrls.error;
}

static int as3645a_probe(struct i2c_client *client,
			 const struct i2c_device_id *devid)
{
	struct as3645a *flash;
	int ret;

	if (client->dev.platform_data == NULL)
		return -ENODEV;

	flash = kzalloc(sizeof(*flash), GFP_KERNEL);
	if (flash == NULL)
		return -ENOMEM;

	flash->pdata = client->dev.platform_data;

	v4l2_i2c_subdev_init(&flash->subdev, client, &as3645a_ops);
	flash->subdev.internal_ops = &as3645a_internal_ops;
	flash->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;

	ret = as3645a_init_controls(flash);
	if (ret < 0)
		goto done;

	ret = media_entity_init(&flash->subdev.entity, 0, NULL, 0);
	if (ret < 0)
		goto done;

	flash->subdev.entity.type = MEDIA_ENT_T_V4L2_SUBDEV_FLASH;

	mutex_init(&flash->power_lock);

	flash->led_mode = V4L2_FLASH_LED_MODE_NONE;

done:
	if (ret < 0) {
		v4l2_ctrl_handler_free(&flash->ctrls);
		kfree(flash);
	}

	return ret;
}

static int as3645a_remove(struct i2c_client *client)
{
	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
	struct as3645a *flash = to_as3645a(subdev);

	v4l2_device_unregister_subdev(subdev);
	v4l2_ctrl_handler_free(&flash->ctrls);
	media_entity_cleanup(&flash->subdev.entity);
	mutex_destroy(&flash->power_lock);
	kfree(flash);

	return 0;
}

static const struct i2c_device_id as3645a_id_table[] = {
	{ AS3645A_NAME, 0 },
	{ },
};
MODULE_DEVICE_TABLE(i2c, as3645a_id_table);

static const struct dev_pm_ops as3645a_pm_ops = {
	.suspend = as3645a_suspend,
	.resume = as3645a_resume,
};

static struct i2c_driver as3645a_i2c_driver = {
	.driver	= {
		.name = AS3645A_NAME,
		.pm   = &as3645a_pm_ops,
	},
	.probe	= as3645a_probe,
	.remove	= as3645a_remove,
	.id_table = as3645a_id_table,
};

module_i2c_driver(as3645a_i2c_driver);

MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
MODULE_DESCRIPTION("LED flash driver for AS3645A, LM3555 and their clones");
MODULE_LICENSE("GPL");