summaryrefslogtreecommitdiff
path: root/drivers/video/backlight/adp8870_bl.c
blob: 5becace3fd0f569d94be2c13269567ee5b75b8dd (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
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Backlight driver for Analog Devices ADP8870 Backlight Devices
 *
 * Copyright 2009-2011 Analog Devices Inc.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/pm.h>
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/fb.h>
#include <linux/backlight.h>
#include <linux/leds.h>
#include <linux/workqueue.h>
#include <linux/slab.h>

#include <linux/platform_data/adp8870.h>
#define ADP8870_EXT_FEATURES
#define ADP8870_USE_LEDS


#define ADP8870_MFDVID	0x00  /* Manufacturer and device ID */
#define ADP8870_MDCR	0x01  /* Device mode and status */
#define ADP8870_INT_STAT 0x02  /* Interrupts status */
#define ADP8870_INT_EN	0x03  /* Interrupts enable */
#define ADP8870_CFGR	0x04  /* Configuration register */
#define ADP8870_BLSEL	0x05  /* Sink enable backlight or independent */
#define ADP8870_PWMLED	0x06  /* PWM Enable Selection Register */
#define ADP8870_BLOFF	0x07  /* Backlight off timeout */
#define ADP8870_BLDIM	0x08  /* Backlight dim timeout */
#define ADP8870_BLFR	0x09  /* Backlight fade in and out rates */
#define ADP8870_BLMX1	0x0A  /* Backlight (Brightness Level 1-daylight) maximum current */
#define ADP8870_BLDM1	0x0B  /* Backlight (Brightness Level 1-daylight) dim current */
#define ADP8870_BLMX2	0x0C  /* Backlight (Brightness Level 2-bright) maximum current */
#define ADP8870_BLDM2	0x0D  /* Backlight (Brightness Level 2-bright) dim current */
#define ADP8870_BLMX3	0x0E  /* Backlight (Brightness Level 3-office) maximum current */
#define ADP8870_BLDM3	0x0F  /* Backlight (Brightness Level 3-office) dim current */
#define ADP8870_BLMX4	0x10  /* Backlight (Brightness Level 4-indoor) maximum current */
#define ADP8870_BLDM4	0x11  /* Backlight (Brightness Level 4-indoor) dim current */
#define ADP8870_BLMX5	0x12  /* Backlight (Brightness Level 5-dark) maximum current */
#define ADP8870_BLDM5	0x13  /* Backlight (Brightness Level 5-dark) dim current */
#define ADP8870_ISCLAW	0x1A  /* Independent sink current fade law register */
#define ADP8870_ISCC	0x1B  /* Independent sink current control register */
#define ADP8870_ISCT1	0x1C  /* Independent Sink Current Timer Register LED[7:5] */
#define ADP8870_ISCT2	0x1D  /* Independent Sink Current Timer Register LED[4:1] */
#define ADP8870_ISCF	0x1E  /* Independent sink current fade register */
#define ADP8870_ISC1	0x1F  /* Independent Sink Current LED1 */
#define ADP8870_ISC2	0x20  /* Independent Sink Current LED2 */
#define ADP8870_ISC3	0x21  /* Independent Sink Current LED3 */
#define ADP8870_ISC4	0x22  /* Independent Sink Current LED4 */
#define ADP8870_ISC5	0x23  /* Independent Sink Current LED5 */
#define ADP8870_ISC6	0x24  /* Independent Sink Current LED6 */
#define ADP8870_ISC7	0x25  /* Independent Sink Current LED7 (Brightness Level 1-daylight) */
#define ADP8870_ISC7_L2	0x26  /* Independent Sink Current LED7 (Brightness Level 2-bright) */
#define ADP8870_ISC7_L3	0x27  /* Independent Sink Current LED7 (Brightness Level 3-office) */
#define ADP8870_ISC7_L4	0x28  /* Independent Sink Current LED7 (Brightness Level 4-indoor) */
#define ADP8870_ISC7_L5	0x29  /* Independent Sink Current LED7 (Brightness Level 5-dark) */
#define ADP8870_CMP_CTL	0x2D  /* ALS Comparator Control Register */
#define ADP8870_ALS1_EN	0x2E  /* Main ALS comparator level enable */
#define ADP8870_ALS2_EN	0x2F  /* Second ALS comparator level enable */
#define ADP8870_ALS1_STAT 0x30  /* Main ALS Comparator Status Register */
#define ADP8870_ALS2_STAT 0x31  /* Second ALS Comparator Status Register */
#define ADP8870_L2TRP	0x32  /* L2 comparator reference */
#define ADP8870_L2HYS	0x33  /* L2 hysteresis */
#define ADP8870_L3TRP	0x34  /* L3 comparator reference */
#define ADP8870_L3HYS	0x35  /* L3 hysteresis */
#define ADP8870_L4TRP	0x36  /* L4 comparator reference */
#define ADP8870_L4HYS	0x37  /* L4 hysteresis */
#define ADP8870_L5TRP	0x38  /* L5 comparator reference */
#define ADP8870_L5HYS	0x39  /* L5 hysteresis */
#define ADP8870_PH1LEVL	0x40  /* First phototransistor ambient light level-low byte register */
#define ADP8870_PH1LEVH	0x41  /* First phototransistor ambient light level-high byte register */
#define ADP8870_PH2LEVL	0x42  /* Second phototransistor ambient light level-low byte register */
#define ADP8870_PH2LEVH	0x43  /* Second phototransistor ambient light level-high byte register */

#define ADP8870_MANUFID		0x3  /* Analog Devices AD8870 Manufacturer and device ID */
#define ADP8870_DEVID(x)	((x) & 0xF)
#define ADP8870_MANID(x)	((x) >> 4)

/* MDCR Device mode and status */
#define D7ALSEN			(1 << 7)
#define INT_CFG			(1 << 6)
#define NSTBY			(1 << 5)
#define DIM_EN			(1 << 4)
#define GDWN_DIS		(1 << 3)
#define SIS_EN			(1 << 2)
#define CMP_AUTOEN		(1 << 1)
#define BLEN			(1 << 0)

/* ADP8870_ALS1_EN Main ALS comparator level enable */
#define L5_EN			(1 << 3)
#define L4_EN			(1 << 2)
#define L3_EN			(1 << 1)
#define L2_EN			(1 << 0)

#define CFGR_BLV_SHIFT		3
#define CFGR_BLV_MASK		0x7
#define ADP8870_FLAG_LED_MASK	0xFF

#define FADE_VAL(in, out)	((0xF & (in)) | ((0xF & (out)) << 4))
#define BL_CFGR_VAL(law, blv)	((((blv) & CFGR_BLV_MASK) << CFGR_BLV_SHIFT) | ((0x3 & (law)) << 1))
#define ALS_CMPR_CFG_VAL(filt)	((0x7 & (filt)) << 1)

struct adp8870_bl {
	struct i2c_client *client;
	struct backlight_device *bl;
	struct adp8870_led *led;
	struct adp8870_backlight_platform_data *pdata;
	struct mutex lock;
	unsigned long cached_daylight_max;
	int id;
	int revid;
	int current_brightness;
};

struct adp8870_led {
	struct led_classdev	cdev;
	struct work_struct	work;
	struct i2c_client	*client;
	enum led_brightness	new_brightness;
	int			id;
	int			flags;
};

static int adp8870_read(struct i2c_client *client, int reg, uint8_t *val)
{
	int ret;

	ret = i2c_smbus_read_byte_data(client, reg);
	if (ret < 0) {
		dev_err(&client->dev, "failed reading at 0x%02x\n", reg);
		return ret;
	}

	*val = ret;
	return 0;
}


static int adp8870_write(struct i2c_client *client, u8 reg, u8 val)
{
	int ret = i2c_smbus_write_byte_data(client, reg, val);

	if (ret)
		dev_err(&client->dev, "failed to write\n");

	return ret;
}

static int adp8870_set_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
{
	struct adp8870_bl *data = i2c_get_clientdata(client);
	uint8_t reg_val;
	int ret;

	mutex_lock(&data->lock);

	ret = adp8870_read(client, reg, &reg_val);

	if (!ret && ((reg_val & bit_mask) != bit_mask)) {
		reg_val |= bit_mask;
		ret = adp8870_write(client, reg, reg_val);
	}

	mutex_unlock(&data->lock);
	return ret;
}

static int adp8870_clr_bits(struct i2c_client *client, int reg, uint8_t bit_mask)
{
	struct adp8870_bl *data = i2c_get_clientdata(client);
	uint8_t reg_val;
	int ret;

	mutex_lock(&data->lock);

	ret = adp8870_read(client, reg, &reg_val);

	if (!ret && (reg_val & bit_mask)) {
		reg_val &= ~bit_mask;
		ret = adp8870_write(client, reg, reg_val);
	}

	mutex_unlock(&data->lock);
	return ret;
}

/*
 * Independent sink / LED
 */
#if defined(ADP8870_USE_LEDS)
static void adp8870_led_work(struct work_struct *work)
{
	struct adp8870_led *led = container_of(work, struct adp8870_led, work);

	adp8870_write(led->client, ADP8870_ISC1 + led->id - 1,
			 led->new_brightness >> 1);
}

static void adp8870_led_set(struct led_classdev *led_cdev,
			   enum led_brightness value)
{
	struct adp8870_led *led;

	led = container_of(led_cdev, struct adp8870_led, cdev);
	led->new_brightness = value;
	/*
	 * Use workqueue for IO since I2C operations can sleep.
	 */
	schedule_work(&led->work);
}

static int adp8870_led_setup(struct adp8870_led *led)
{
	struct i2c_client *client = led->client;
	int ret = 0;

	ret = adp8870_write(client, ADP8870_ISC1 + led->id - 1, 0);
	if (ret)
		return ret;

	ret = adp8870_set_bits(client, ADP8870_ISCC, 1 << (led->id - 1));
	if (ret)
		return ret;

	if (led->id > 4)
		ret = adp8870_set_bits(client, ADP8870_ISCT1,
				(led->flags & 0x3) << ((led->id - 5) * 2));
	else
		ret = adp8870_set_bits(client, ADP8870_ISCT2,
				(led->flags & 0x3) << ((led->id - 1) * 2));

	return ret;
}

static int adp8870_led_probe(struct i2c_client *client)
{
	struct adp8870_backlight_platform_data *pdata =
		dev_get_platdata(&client->dev);
	struct adp8870_bl *data = i2c_get_clientdata(client);
	struct adp8870_led *led, *led_dat;
	struct led_info *cur_led;
	int ret, i;

	led = devm_kcalloc(&client->dev, pdata->num_leds, sizeof(*led),
				GFP_KERNEL);
	if (led == NULL)
		return -ENOMEM;

	ret = adp8870_write(client, ADP8870_ISCLAW, pdata->led_fade_law);
	if (ret)
		return ret;

	ret = adp8870_write(client, ADP8870_ISCT1,
			(pdata->led_on_time & 0x3) << 6);
	if (ret)
		return ret;

	ret = adp8870_write(client, ADP8870_ISCF,
			FADE_VAL(pdata->led_fade_in, pdata->led_fade_out));
	if (ret)
		return ret;

	for (i = 0; i < pdata->num_leds; ++i) {
		cur_led = &pdata->leds[i];
		led_dat = &led[i];

		led_dat->id = cur_led->flags & ADP8870_FLAG_LED_MASK;

		if (led_dat->id > 7 || led_dat->id < 1) {
			dev_err(&client->dev, "Invalid LED ID %d\n",
				led_dat->id);
			ret = -EINVAL;
			goto err;
		}

		if (pdata->bl_led_assign & (1 << (led_dat->id - 1))) {
			dev_err(&client->dev, "LED %d used by Backlight\n",
				led_dat->id);
			ret = -EBUSY;
			goto err;
		}

		led_dat->cdev.name = cur_led->name;
		led_dat->cdev.default_trigger = cur_led->default_trigger;
		led_dat->cdev.brightness_set = adp8870_led_set;
		led_dat->cdev.brightness = LED_OFF;
		led_dat->flags = cur_led->flags >> FLAG_OFFT_SHIFT;
		led_dat->client = client;
		led_dat->new_brightness = LED_OFF;
		INIT_WORK(&led_dat->work, adp8870_led_work);

		ret = led_classdev_register(&client->dev, &led_dat->cdev);
		if (ret) {
			dev_err(&client->dev, "failed to register LED %d\n",
				led_dat->id);
			goto err;
		}

		ret = adp8870_led_setup(led_dat);
		if (ret) {
			dev_err(&client->dev, "failed to write\n");
			i++;
			goto err;
		}
	}

	data->led = led;

	return 0;

 err:
	for (i = i - 1; i >= 0; --i) {
		led_classdev_unregister(&led[i].cdev);
		cancel_work_sync(&led[i].work);
	}

	return ret;
}

static int adp8870_led_remove(struct i2c_client *client)
{
	struct adp8870_backlight_platform_data *pdata =
		dev_get_platdata(&client->dev);
	struct adp8870_bl *data = i2c_get_clientdata(client);
	int i;

	for (i = 0; i < pdata->num_leds; i++) {
		led_classdev_unregister(&data->led[i].cdev);
		cancel_work_sync(&data->led[i].work);
	}

	return 0;
}
#else
static int adp8870_led_probe(struct i2c_client *client)
{
	return 0;
}

static int adp8870_led_remove(struct i2c_client *client)
{
	return 0;
}
#endif

static int adp8870_bl_set(struct backlight_device *bl, int brightness)
{
	struct adp8870_bl *data = bl_get_data(bl);
	struct i2c_client *client = data->client;
	int ret = 0;

	if (data->pdata->en_ambl_sens) {
		if ((brightness > 0) && (brightness < ADP8870_MAX_BRIGHTNESS)) {
			/* Disable Ambient Light auto adjust */
			ret = adp8870_clr_bits(client, ADP8870_MDCR,
					CMP_AUTOEN);
			if (ret)
				return ret;
			ret = adp8870_write(client, ADP8870_BLMX1, brightness);
			if (ret)
				return ret;
		} else {
			/*
			 * MAX_BRIGHTNESS -> Enable Ambient Light auto adjust
			 * restore daylight l1 sysfs brightness
			 */
			ret = adp8870_write(client, ADP8870_BLMX1,
					 data->cached_daylight_max);
			if (ret)
				return ret;

			ret = adp8870_set_bits(client, ADP8870_MDCR,
					 CMP_AUTOEN);
			if (ret)
				return ret;
		}
	} else {
		ret = adp8870_write(client, ADP8870_BLMX1, brightness);
		if (ret)
			return ret;
	}

	if (data->current_brightness && brightness == 0)
		ret = adp8870_set_bits(client,
				ADP8870_MDCR, DIM_EN);
	else if (data->current_brightness == 0 && brightness)
		ret = adp8870_clr_bits(client,
				ADP8870_MDCR, DIM_EN);

	if (!ret)
		data->current_brightness = brightness;

	return ret;
}

static int adp8870_bl_update_status(struct backlight_device *bl)
{
	return adp8870_bl_set(bl, backlight_get_brightness(bl));
}

static int adp8870_bl_get_brightness(struct backlight_device *bl)
{
	struct adp8870_bl *data = bl_get_data(bl);

	return data->current_brightness;
}

static const struct backlight_ops adp8870_bl_ops = {
	.update_status	= adp8870_bl_update_status,
	.get_brightness	= adp8870_bl_get_brightness,
};

static int adp8870_bl_setup(struct backlight_device *bl)
{
	struct adp8870_bl *data = bl_get_data(bl);
	struct i2c_client *client = data->client;
	struct adp8870_backlight_platform_data *pdata = data->pdata;
	int ret = 0;

	ret = adp8870_write(client, ADP8870_BLSEL, ~pdata->bl_led_assign);
	if (ret)
		return ret;

	ret = adp8870_write(client, ADP8870_PWMLED, pdata->pwm_assign);
	if (ret)
		return ret;

	ret = adp8870_write(client, ADP8870_BLMX1, pdata->l1_daylight_max);
	if (ret)
		return ret;

	ret = adp8870_write(client, ADP8870_BLDM1, pdata->l1_daylight_dim);
	if (ret)
		return ret;

	if (pdata->en_ambl_sens) {
		data->cached_daylight_max = pdata->l1_daylight_max;
		ret = adp8870_write(client, ADP8870_BLMX2,
						pdata->l2_bright_max);
		if (ret)
			return ret;
		ret = adp8870_write(client, ADP8870_BLDM2,
						pdata->l2_bright_dim);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_BLMX3,
						pdata->l3_office_max);
		if (ret)
			return ret;
		ret = adp8870_write(client, ADP8870_BLDM3,
						pdata->l3_office_dim);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_BLMX4,
						pdata->l4_indoor_max);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_BLDM4,
						pdata->l4_indor_dim);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_BLMX5,
						pdata->l5_dark_max);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_BLDM5,
						pdata->l5_dark_dim);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_L2TRP, pdata->l2_trip);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_L2HYS, pdata->l2_hyst);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_L3TRP, pdata->l3_trip);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_L3HYS, pdata->l3_hyst);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_L4TRP, pdata->l4_trip);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_L4HYS, pdata->l4_hyst);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_L5TRP, pdata->l5_trip);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_L5HYS, pdata->l5_hyst);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_ALS1_EN, L5_EN | L4_EN |
						L3_EN | L2_EN);
		if (ret)
			return ret;

		ret = adp8870_write(client, ADP8870_CMP_CTL,
			ALS_CMPR_CFG_VAL(pdata->abml_filt));
		if (ret)
			return ret;
	}

	ret = adp8870_write(client, ADP8870_CFGR,
			BL_CFGR_VAL(pdata->bl_fade_law, 0));
	if (ret)
		return ret;

	ret = adp8870_write(client, ADP8870_BLFR, FADE_VAL(pdata->bl_fade_in,
			pdata->bl_fade_out));
	if (ret)
		return ret;
	/*
	 * ADP8870 Rev0 requires GDWN_DIS bit set
	 */

	ret = adp8870_set_bits(client, ADP8870_MDCR, BLEN | DIM_EN | NSTBY |
			(data->revid == 0 ? GDWN_DIS : 0));

	return ret;
}

static ssize_t adp8870_show(struct device *dev, char *buf, int reg)
{
	struct adp8870_bl *data = dev_get_drvdata(dev);
	int error;
	uint8_t reg_val;

	mutex_lock(&data->lock);
	error = adp8870_read(data->client, reg, &reg_val);
	mutex_unlock(&data->lock);

	if (error < 0)
		return error;

	return sprintf(buf, "%u\n", reg_val);
}

static ssize_t adp8870_store(struct device *dev, const char *buf,
			 size_t count, int reg)
{
	struct adp8870_bl *data = dev_get_drvdata(dev);
	unsigned long val;
	int ret;

	ret = kstrtoul(buf, 10, &val);
	if (ret)
		return ret;

	mutex_lock(&data->lock);
	adp8870_write(data->client, reg, val);
	mutex_unlock(&data->lock);

	return count;
}

static ssize_t adp8870_bl_l5_dark_max_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	return adp8870_show(dev, buf, ADP8870_BLMX5);
}

static ssize_t adp8870_bl_l5_dark_max_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	return adp8870_store(dev, buf, count, ADP8870_BLMX5);
}
static DEVICE_ATTR(l5_dark_max, 0664, adp8870_bl_l5_dark_max_show,
			adp8870_bl_l5_dark_max_store);


static ssize_t adp8870_bl_l4_indoor_max_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	return adp8870_show(dev, buf, ADP8870_BLMX4);
}

static ssize_t adp8870_bl_l4_indoor_max_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	return adp8870_store(dev, buf, count, ADP8870_BLMX4);
}
static DEVICE_ATTR(l4_indoor_max, 0664, adp8870_bl_l4_indoor_max_show,
			adp8870_bl_l4_indoor_max_store);


static ssize_t adp8870_bl_l3_office_max_show(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	return adp8870_show(dev, buf, ADP8870_BLMX3);
}

static ssize_t adp8870_bl_l3_office_max_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	return adp8870_store(dev, buf, count, ADP8870_BLMX3);
}

static DEVICE_ATTR(l3_office_max, 0664, adp8870_bl_l3_office_max_show,
			adp8870_bl_l3_office_max_store);

static ssize_t adp8870_bl_l2_bright_max_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	return adp8870_show(dev, buf, ADP8870_BLMX2);
}

static ssize_t adp8870_bl_l2_bright_max_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	return adp8870_store(dev, buf, count, ADP8870_BLMX2);
}
static DEVICE_ATTR(l2_bright_max, 0664, adp8870_bl_l2_bright_max_show,
			adp8870_bl_l2_bright_max_store);

static ssize_t adp8870_bl_l1_daylight_max_show(struct device *dev,
			struct device_attribute *attr, char *buf)
{
	return adp8870_show(dev, buf, ADP8870_BLMX1);
}

static ssize_t adp8870_bl_l1_daylight_max_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	struct adp8870_bl *data = dev_get_drvdata(dev);
	int ret = kstrtoul(buf, 10, &data->cached_daylight_max);

	if (ret)
		return ret;

	return adp8870_store(dev, buf, count, ADP8870_BLMX1);
}
static DEVICE_ATTR(l1_daylight_max, 0664, adp8870_bl_l1_daylight_max_show,
			adp8870_bl_l1_daylight_max_store);

static ssize_t adp8870_bl_l5_dark_dim_show(struct device *dev,
			struct device_attribute *attr, char *buf)
{
	return adp8870_show(dev, buf, ADP8870_BLDM5);
}

static ssize_t adp8870_bl_l5_dark_dim_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	return adp8870_store(dev, buf, count, ADP8870_BLDM5);
}
static DEVICE_ATTR(l5_dark_dim, 0664, adp8870_bl_l5_dark_dim_show,
			adp8870_bl_l5_dark_dim_store);

static ssize_t adp8870_bl_l4_indoor_dim_show(struct device *dev,
			struct device_attribute *attr, char *buf)
{
	return adp8870_show(dev, buf, ADP8870_BLDM4);
}

static ssize_t adp8870_bl_l4_indoor_dim_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	return adp8870_store(dev, buf, count, ADP8870_BLDM4);
}
static DEVICE_ATTR(l4_indoor_dim, 0664, adp8870_bl_l4_indoor_dim_show,
			adp8870_bl_l4_indoor_dim_store);


static ssize_t adp8870_bl_l3_office_dim_show(struct device *dev,
			struct device_attribute *attr, char *buf)
{
	return adp8870_show(dev, buf, ADP8870_BLDM3);
}

static ssize_t adp8870_bl_l3_office_dim_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	return adp8870_store(dev, buf, count, ADP8870_BLDM3);
}
static DEVICE_ATTR(l3_office_dim, 0664, adp8870_bl_l3_office_dim_show,
			adp8870_bl_l3_office_dim_store);

static ssize_t adp8870_bl_l2_bright_dim_show(struct device *dev,
			struct device_attribute *attr, char *buf)
{
	return adp8870_show(dev, buf, ADP8870_BLDM2);
}

static ssize_t adp8870_bl_l2_bright_dim_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	return adp8870_store(dev, buf, count, ADP8870_BLDM2);
}
static DEVICE_ATTR(l2_bright_dim, 0664, adp8870_bl_l2_bright_dim_show,
			adp8870_bl_l2_bright_dim_store);

static ssize_t adp8870_bl_l1_daylight_dim_show(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	return adp8870_show(dev, buf, ADP8870_BLDM1);
}

static ssize_t adp8870_bl_l1_daylight_dim_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	return adp8870_store(dev, buf, count, ADP8870_BLDM1);
}
static DEVICE_ATTR(l1_daylight_dim, 0664, adp8870_bl_l1_daylight_dim_show,
			adp8870_bl_l1_daylight_dim_store);

#ifdef ADP8870_EXT_FEATURES
static ssize_t adp8870_bl_ambient_light_level_show(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	struct adp8870_bl *data = dev_get_drvdata(dev);
	int error;
	uint8_t reg_val;
	uint16_t ret_val;

	mutex_lock(&data->lock);
	error = adp8870_read(data->client, ADP8870_PH1LEVL, &reg_val);
	if (error < 0) {
		mutex_unlock(&data->lock);
		return error;
	}
	ret_val = reg_val;
	error = adp8870_read(data->client, ADP8870_PH1LEVH, &reg_val);
	mutex_unlock(&data->lock);

	if (error < 0)
		return error;

	/* Return 13-bit conversion value for the first light sensor */
	ret_val += (reg_val & 0x1F) << 8;

	return sprintf(buf, "%u\n", ret_val);
}
static DEVICE_ATTR(ambient_light_level, 0444,
		adp8870_bl_ambient_light_level_show, NULL);

static ssize_t adp8870_bl_ambient_light_zone_show(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	struct adp8870_bl *data = dev_get_drvdata(dev);
	int error;
	uint8_t reg_val;

	mutex_lock(&data->lock);
	error = adp8870_read(data->client, ADP8870_CFGR, &reg_val);
	mutex_unlock(&data->lock);

	if (error < 0)
		return error;

	return sprintf(buf, "%u\n",
		((reg_val >> CFGR_BLV_SHIFT) & CFGR_BLV_MASK) + 1);
}

static ssize_t adp8870_bl_ambient_light_zone_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	struct adp8870_bl *data = dev_get_drvdata(dev);
	unsigned long val;
	uint8_t reg_val;
	int ret;

	ret = kstrtoul(buf, 10, &val);
	if (ret)
		return ret;

	if (val == 0) {
		/* Enable automatic ambient light sensing */
		adp8870_set_bits(data->client, ADP8870_MDCR, CMP_AUTOEN);
	} else if ((val > 0) && (val < 6)) {
		/* Disable automatic ambient light sensing */
		adp8870_clr_bits(data->client, ADP8870_MDCR, CMP_AUTOEN);

		/* Set user supplied ambient light zone */
		mutex_lock(&data->lock);
		ret = adp8870_read(data->client, ADP8870_CFGR, &reg_val);
		if (!ret) {
			reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT);
			reg_val |= (val - 1) << CFGR_BLV_SHIFT;
			adp8870_write(data->client, ADP8870_CFGR, reg_val);
		}
		mutex_unlock(&data->lock);
	}

	return count;
}
static DEVICE_ATTR(ambient_light_zone, 0664,
		adp8870_bl_ambient_light_zone_show,
		adp8870_bl_ambient_light_zone_store);
#endif

static struct attribute *adp8870_bl_attributes[] = {
	&dev_attr_l5_dark_max.attr,
	&dev_attr_l5_dark_dim.attr,
	&dev_attr_l4_indoor_max.attr,
	&dev_attr_l4_indoor_dim.attr,
	&dev_attr_l3_office_max.attr,
	&dev_attr_l3_office_dim.attr,
	&dev_attr_l2_bright_max.attr,
	&dev_attr_l2_bright_dim.attr,
	&dev_attr_l1_daylight_max.attr,
	&dev_attr_l1_daylight_dim.attr,
#ifdef ADP8870_EXT_FEATURES
	&dev_attr_ambient_light_level.attr,
	&dev_attr_ambient_light_zone.attr,
#endif
	NULL
};

static const struct attribute_group adp8870_bl_attr_group = {
	.attrs = adp8870_bl_attributes,
};

static int adp8870_probe(struct i2c_client *client,
					const struct i2c_device_id *id)
{
	struct backlight_properties props;
	struct backlight_device *bl;
	struct adp8870_bl *data;
	struct adp8870_backlight_platform_data *pdata =
		dev_get_platdata(&client->dev);
	uint8_t reg_val;
	int ret;

	if (!i2c_check_functionality(client->adapter,
					I2C_FUNC_SMBUS_BYTE_DATA)) {
		dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
		return -EIO;
	}

	if (!pdata) {
		dev_err(&client->dev, "no platform data?\n");
		return -EINVAL;
	}

	ret = adp8870_read(client, ADP8870_MFDVID, &reg_val);
	if (ret < 0)
		return -EIO;

	if (ADP8870_MANID(reg_val) != ADP8870_MANUFID) {
		dev_err(&client->dev, "failed to probe\n");
		return -ENODEV;
	}

	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
	if (data == NULL)
		return -ENOMEM;

	data->revid = ADP8870_DEVID(reg_val);
	data->client = client;
	data->pdata = pdata;
	data->id = id->driver_data;
	data->current_brightness = 0;
	i2c_set_clientdata(client, data);

	mutex_init(&data->lock);

	memset(&props, 0, sizeof(props));
	props.type = BACKLIGHT_RAW;
	props.max_brightness = props.brightness = ADP8870_MAX_BRIGHTNESS;
	bl = devm_backlight_device_register(&client->dev,
				dev_driver_string(&client->dev),
				&client->dev, data, &adp8870_bl_ops, &props);
	if (IS_ERR(bl)) {
		dev_err(&client->dev, "failed to register backlight\n");
		return PTR_ERR(bl);
	}

	data->bl = bl;

	if (pdata->en_ambl_sens) {
		ret = sysfs_create_group(&bl->dev.kobj,
			&adp8870_bl_attr_group);
		if (ret) {
			dev_err(&client->dev, "failed to register sysfs\n");
			return ret;
		}
	}

	ret = adp8870_bl_setup(bl);
	if (ret) {
		ret = -EIO;
		goto out;
	}

	backlight_update_status(bl);

	dev_info(&client->dev, "Rev.%d Backlight\n", data->revid);

	if (pdata->num_leds)
		adp8870_led_probe(client);

	return 0;

out:
	if (data->pdata->en_ambl_sens)
		sysfs_remove_group(&data->bl->dev.kobj,
			&adp8870_bl_attr_group);

	return ret;
}

static void adp8870_remove(struct i2c_client *client)
{
	struct adp8870_bl *data = i2c_get_clientdata(client);

	adp8870_clr_bits(client, ADP8870_MDCR, NSTBY);

	if (data->led)
		adp8870_led_remove(client);

	if (data->pdata->en_ambl_sens)
		sysfs_remove_group(&data->bl->dev.kobj,
			&adp8870_bl_attr_group);
}

#ifdef CONFIG_PM_SLEEP
static int adp8870_i2c_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);

	adp8870_clr_bits(client, ADP8870_MDCR, NSTBY);

	return 0;
}

static int adp8870_i2c_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);

	adp8870_set_bits(client, ADP8870_MDCR, NSTBY | BLEN);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(adp8870_i2c_pm_ops, adp8870_i2c_suspend,
			adp8870_i2c_resume);

static const struct i2c_device_id adp8870_id[] = {
	{ "adp8870", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, adp8870_id);

static struct i2c_driver adp8870_driver = {
	.driver = {
		.name	= KBUILD_MODNAME,
		.pm	= &adp8870_i2c_pm_ops,
	},
	.probe    = adp8870_probe,
	.remove   = adp8870_remove,
	.id_table = adp8870_id,
};

module_i2c_driver(adp8870_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("ADP8870 Backlight driver");