aboutsummaryrefslogtreecommitdiff
path: root/drivers/input/keyboard/lm8323.c
blob: 82d1dc8badd5472df8ca2cfd6d90c82a06076be7 (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
/*
 * drivers/i2c/chips/lm8323.c
 *
 * Copyright (C) 2007-2009 Nokia Corporation
 *
 * Written by Daniel Stone <daniel.stone@nokia.com>
 *            Timo O. Karjalainen <timo.o.karjalainen@nokia.com>
 *
 * Updated by Felipe Balbi <felipe.balbi@nokia.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation (version 2 of the License only).
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/leds.h>
#include <linux/pm.h>
#include <linux/i2c/lm8323.h>
#include <linux/slab.h>

/* Commands to send to the chip. */
#define LM8323_CMD_READ_ID		0x80 /* Read chip ID. */
#define LM8323_CMD_WRITE_CFG		0x81 /* Set configuration item. */
#define LM8323_CMD_READ_INT		0x82 /* Get interrupt status. */
#define LM8323_CMD_RESET		0x83 /* Reset, same as external one */
#define LM8323_CMD_WRITE_PORT_SEL	0x85 /* Set GPIO in/out. */
#define LM8323_CMD_WRITE_PORT_STATE	0x86 /* Set GPIO pullup. */
#define LM8323_CMD_READ_PORT_SEL	0x87 /* Get GPIO in/out. */
#define LM8323_CMD_READ_PORT_STATE	0x88 /* Get GPIO pullup. */
#define LM8323_CMD_READ_FIFO		0x89 /* Read byte from FIFO. */
#define LM8323_CMD_RPT_READ_FIFO	0x8a /* Read FIFO (no increment). */
#define LM8323_CMD_SET_ACTIVE		0x8b /* Set active time. */
#define LM8323_CMD_READ_ERR		0x8c /* Get error status. */
#define LM8323_CMD_READ_ROTATOR		0x8e /* Read rotator status. */
#define LM8323_CMD_SET_DEBOUNCE		0x8f /* Set debouncing time. */
#define LM8323_CMD_SET_KEY_SIZE		0x90 /* Set keypad size. */
#define LM8323_CMD_READ_KEY_SIZE	0x91 /* Get keypad size. */
#define LM8323_CMD_READ_CFG		0x92 /* Get configuration item. */
#define LM8323_CMD_WRITE_CLOCK		0x93 /* Set clock config. */
#define LM8323_CMD_READ_CLOCK		0x94 /* Get clock config. */
#define LM8323_CMD_PWM_WRITE		0x95 /* Write PWM script. */
#define LM8323_CMD_START_PWM		0x96 /* Start PWM engine. */
#define LM8323_CMD_STOP_PWM		0x97 /* Stop PWM engine. */

/* Interrupt status. */
#define INT_KEYPAD			0x01 /* Key event. */
#define INT_ROTATOR			0x02 /* Rotator event. */
#define INT_ERROR			0x08 /* Error: use CMD_READ_ERR. */
#define INT_NOINIT			0x10 /* Lost configuration. */
#define INT_PWM1			0x20 /* PWM1 stopped. */
#define INT_PWM2			0x40 /* PWM2 stopped. */
#define INT_PWM3			0x80 /* PWM3 stopped. */

/* Errors (signalled by INT_ERROR, read with CMD_READ_ERR). */
#define ERR_BADPAR			0x01 /* Bad parameter. */
#define ERR_CMDUNK			0x02 /* Unknown command. */
#define ERR_KEYOVR			0x04 /* Too many keys pressed. */
#define ERR_FIFOOVER			0x40 /* FIFO overflow. */

/* Configuration keys (CMD_{WRITE,READ}_CFG). */
#define CFG_MUX1SEL			0x01 /* Select MUX1_OUT input. */
#define CFG_MUX1EN			0x02 /* Enable MUX1_OUT. */
#define CFG_MUX2SEL			0x04 /* Select MUX2_OUT input. */
#define CFG_MUX2EN			0x08 /* Enable MUX2_OUT. */
#define CFG_PSIZE			0x20 /* Package size (must be 0). */
#define CFG_ROTEN			0x40 /* Enable rotator. */

/* Clock settings (CMD_{WRITE,READ}_CLOCK). */
#define CLK_RCPWM_INTERNAL		0x00
#define CLK_RCPWM_EXTERNAL		0x03
#define CLK_SLOWCLKEN			0x08 /* Enable 32.768kHz clock. */
#define CLK_SLOWCLKOUT			0x40 /* Enable slow pulse output. */

/* The possible addresses corresponding to CONFIG1 and CONFIG2 pin wirings. */
#define LM8323_I2C_ADDR00		(0x84 >> 1)	/* 1000 010x */
#define LM8323_I2C_ADDR01		(0x86 >> 1)	/* 1000 011x */
#define LM8323_I2C_ADDR10		(0x88 >> 1)	/* 1000 100x */
#define LM8323_I2C_ADDR11		(0x8A >> 1)	/* 1000 101x */

/* Key event fifo length */
#define LM8323_FIFO_LEN			15

/* Commands for PWM engine; feed in with PWM_WRITE. */
/* Load ramp counter from duty cycle field (range 0 - 0xff). */
#define PWM_SET(v)			(0x4000 | ((v) & 0xff))
/* Go to start of script. */
#define PWM_GOTOSTART			0x0000
/*
 * Stop engine (generates interrupt).  If reset is 1, clear the program
 * counter, else leave it.
 */
#define PWM_END(reset)			(0xc000 | (!!(reset) << 11))
/*
 * Ramp.  If s is 1, divide clock by 512, else divide clock by 16.
 * Take t clock scales (up to 63) per step, for n steps (up to 126).
 * If u is set, ramp up, else ramp down.
 */
#define PWM_RAMP(s, t, n, u)		((!!(s) << 14) | ((t) & 0x3f) << 8 | \
					 ((n) & 0x7f) | ((u) ? 0 : 0x80))
/*
 * Loop (i.e. jump back to pos) for a given number of iterations (up to 63).
 * If cnt is zero, execute until PWM_END is encountered.
 */
#define PWM_LOOP(cnt, pos)		(0xa000 | (((cnt) & 0x3f) << 7) | \
					 ((pos) & 0x3f))
/*
 * Wait for trigger.  Argument is a mask of channels, shifted by the channel
 * number, e.g. 0xa for channels 3 and 1.  Note that channels are numbered
 * from 1, not 0.
 */
#define PWM_WAIT_TRIG(chans)		(0xe000 | (((chans) & 0x7) << 6))
/* Send trigger.  Argument is same as PWM_WAIT_TRIG. */
#define PWM_SEND_TRIG(chans)		(0xe000 | ((chans) & 0x7))

struct lm8323_pwm {
	int			id;
	int			fade_time;
	int			brightness;
	int			desired_brightness;
	bool			enabled;
	bool			running;
	/* pwm lock */
	struct mutex		lock;
	struct work_struct	work;
	struct led_classdev	cdev;
	struct lm8323_chip	*chip;
};

struct lm8323_chip {
	/* device lock */
	struct mutex		lock;
	struct i2c_client	*client;
	struct input_dev	*idev;
	bool			kp_enabled;
	bool			pm_suspend;
	unsigned		keys_down;
	char			phys[32];
	unsigned short		keymap[LM8323_KEYMAP_SIZE];
	int			size_x;
	int			size_y;
	int			debounce_time;
	int			active_time;
	struct lm8323_pwm	pwm[LM8323_NUM_PWMS];
};

#define client_to_lm8323(c)	container_of(c, struct lm8323_chip, client)
#define dev_to_lm8323(d)	container_of(d, struct lm8323_chip, client->dev)
#define cdev_to_pwm(c)		container_of(c, struct lm8323_pwm, cdev)
#define work_to_pwm(w)		container_of(w, struct lm8323_pwm, work)

#define LM8323_MAX_DATA 8

/*
 * To write, we just access the chip's address in write mode, and dump the
 * command and data out on the bus.  The command byte and data are taken as
 * sequential u8s out of varargs, to a maximum of LM8323_MAX_DATA.
 */
static int lm8323_write(struct lm8323_chip *lm, int len, ...)
{
	int ret, i;
	va_list ap;
	u8 data[LM8323_MAX_DATA];

	va_start(ap, len);

	if (unlikely(len > LM8323_MAX_DATA)) {
		dev_err(&lm->client->dev, "tried to send %d bytes\n", len);
		va_end(ap);
		return 0;
	}

	for (i = 0; i < len; i++)
		data[i] = va_arg(ap, int);

	va_end(ap);

	/*
	 * If the host is asleep while we send the data, we can get a NACK
	 * back while it wakes up, so try again, once.
	 */
	ret = i2c_master_send(lm->client, data, len);
	if (unlikely(ret == -EREMOTEIO))
		ret = i2c_master_send(lm->client, data, len);
	if (unlikely(ret != len))
		dev_err(&lm->client->dev, "sent %d bytes of %d total\n",
			len, ret);

	return ret;
}

/*
 * To read, we first send the command byte to the chip and end the transaction,
 * then access the chip in read mode, at which point it will send the data.
 */
static int lm8323_read(struct lm8323_chip *lm, u8 cmd, u8 *buf, int len)
{
	int ret;

	/*
	 * If the host is asleep while we send the byte, we can get a NACK
	 * back while it wakes up, so try again, once.
	 */
	ret = i2c_master_send(lm->client, &cmd, 1);
	if (unlikely(ret == -EREMOTEIO))
		ret = i2c_master_send(lm->client, &cmd, 1);
	if (unlikely(ret != 1)) {
		dev_err(&lm->client->dev, "sending read cmd 0x%02x failed\n",
			cmd);
		return 0;
	}

	ret = i2c_master_recv(lm->client, buf, len);
	if (unlikely(ret != len))
		dev_err(&lm->client->dev, "wanted %d bytes, got %d\n",
			len, ret);

	return ret;
}

/*
 * Set the chip active time (idle time before it enters halt).
 */
static void lm8323_set_active_time(struct lm8323_chip *lm, int time)
{
	lm8323_write(lm, 2, LM8323_CMD_SET_ACTIVE, time >> 2);
}

/*
 * The signals are AT-style: the low 7 bits are the keycode, and the top
 * bit indicates the state (1 for down, 0 for up).
 */
static inline u8 lm8323_whichkey(u8 event)
{
	return event & 0x7f;
}

static inline int lm8323_ispress(u8 event)
{
	return (event & 0x80) ? 1 : 0;
}

static void process_keys(struct lm8323_chip *lm)
{
	u8 event;
	u8 key_fifo[LM8323_FIFO_LEN + 1];
	int old_keys_down = lm->keys_down;
	int ret;
	int i = 0;

	/*
	 * Read all key events from the FIFO at once. Next READ_FIFO clears the
	 * FIFO even if we didn't read all events previously.
	 */
	ret = lm8323_read(lm, LM8323_CMD_READ_FIFO, key_fifo, LM8323_FIFO_LEN);

	if (ret < 0) {
		dev_err(&lm->client->dev, "Failed reading fifo \n");
		return;
	}
	key_fifo[ret] = 0;

	while ((event = key_fifo[i++])) {
		u8 key = lm8323_whichkey(event);
		int isdown = lm8323_ispress(event);
		unsigned short keycode = lm->keymap[key];

		dev_vdbg(&lm->client->dev, "key 0x%02x %s\n",
			 key, isdown ? "down" : "up");

		if (lm->kp_enabled) {
			input_event(lm->idev, EV_MSC, MSC_SCAN, key);
			input_report_key(lm->idev, keycode, isdown);
			input_sync(lm->idev);
		}

		if (isdown)
			lm->keys_down++;
		else
			lm->keys_down--;
	}

	/*
	 * Errata: We need to ensure that the chip never enters halt mode
	 * during a keypress, so set active time to 0.  When it's released,
	 * we can enter halt again, so set the active time back to normal.
	 */
	if (!old_keys_down && lm->keys_down)
		lm8323_set_active_time(lm, 0);
	if (old_keys_down && !lm->keys_down)
		lm8323_set_active_time(lm, lm->active_time);
}

static void lm8323_process_error(struct lm8323_chip *lm)
{
	u8 error;

	if (lm8323_read(lm, LM8323_CMD_READ_ERR, &error, 1) == 1) {
		if (error & ERR_FIFOOVER)
			dev_vdbg(&lm->client->dev, "fifo overflow!\n");
		if (error & ERR_KEYOVR)
			dev_vdbg(&lm->client->dev,
					"more than two keys pressed\n");
		if (error & ERR_CMDUNK)
			dev_vdbg(&lm->client->dev,
					"unknown command submitted\n");
		if (error & ERR_BADPAR)
			dev_vdbg(&lm->client->dev, "bad command parameter\n");
	}
}

static void lm8323_reset(struct lm8323_chip *lm)
{
	/* The docs say we must pass 0xAA as the data byte. */
	lm8323_write(lm, 2, LM8323_CMD_RESET, 0xAA);
}

static int lm8323_configure(struct lm8323_chip *lm)
{
	int keysize = (lm->size_x << 4) | lm->size_y;
	int clock = (CLK_SLOWCLKEN | CLK_RCPWM_EXTERNAL);
	int debounce = lm->debounce_time >> 2;
	int active = lm->active_time >> 2;

	/*
	 * Active time must be greater than the debounce time: if it's
	 * a close-run thing, give ourselves a 12ms buffer.
	 */
	if (debounce >= active)
		active = debounce + 3;

	lm8323_write(lm, 2, LM8323_CMD_WRITE_CFG, 0);
	lm8323_write(lm, 2, LM8323_CMD_WRITE_CLOCK, clock);
	lm8323_write(lm, 2, LM8323_CMD_SET_KEY_SIZE, keysize);
	lm8323_set_active_time(lm, lm->active_time);
	lm8323_write(lm, 2, LM8323_CMD_SET_DEBOUNCE, debounce);
	lm8323_write(lm, 3, LM8323_CMD_WRITE_PORT_STATE, 0xff, 0xff);
	lm8323_write(lm, 3, LM8323_CMD_WRITE_PORT_SEL, 0, 0);

	/*
	 * Not much we can do about errors at this point, so just hope
	 * for the best.
	 */

	return 0;
}

static void pwm_done(struct lm8323_pwm *pwm)
{
	mutex_lock(&pwm->lock);
	pwm->running = false;
	if (pwm->desired_brightness != pwm->brightness)
		schedule_work(&pwm->work);
	mutex_unlock(&pwm->lock);
}

/*
 * Bottom half: handle the interrupt by posting key events, or dealing with
 * errors appropriately.
 */
static irqreturn_t lm8323_irq(int irq, void *_lm)
{
	struct lm8323_chip *lm = _lm;
	u8 ints;
	int i;

	mutex_lock(&lm->lock);

	while ((lm8323_read(lm, LM8323_CMD_READ_INT, &ints, 1) == 1) && ints) {
		if (likely(ints & INT_KEYPAD))
			process_keys(lm);
		if (ints & INT_ROTATOR) {
			/* We don't currently support the rotator. */
			dev_vdbg(&lm->client->dev, "rotator fired\n");
		}
		if (ints & INT_ERROR) {
			dev_vdbg(&lm->client->dev, "error!\n");
			lm8323_process_error(lm);
		}
		if (ints & INT_NOINIT) {
			dev_err(&lm->client->dev, "chip lost config; "
						  "reinitialising\n");
			lm8323_configure(lm);
		}
		for (i = 0; i < LM8323_NUM_PWMS; i++) {
			if (ints & (1 << (INT_PWM1 + i))) {
				dev_vdbg(&lm->client->dev,
					 "pwm%d engine completed\n", i);
				pwm_done(&lm->pwm[i]);
			}
		}
	}

	mutex_unlock(&lm->lock);

	return IRQ_HANDLED;
}

/*
 * Read the chip ID.
 */
static int lm8323_read_id(struct lm8323_chip *lm, u8 *buf)
{
	int bytes;

	bytes = lm8323_read(lm, LM8323_CMD_READ_ID, buf, 2);
	if (unlikely(bytes != 2))
		return -EIO;

	return 0;
}

static void lm8323_write_pwm_one(struct lm8323_pwm *pwm, int pos, u16 cmd)
{
	lm8323_write(pwm->chip, 4, LM8323_CMD_PWM_WRITE, (pos << 2) | pwm->id,
		     (cmd & 0xff00) >> 8, cmd & 0x00ff);
}

/*
 * Write a script into a given PWM engine, concluding with PWM_END.
 * If 'kill' is nonzero, the engine will be shut down at the end
 * of the script, producing a zero output. Otherwise the engine
 * will be kept running at the final PWM level indefinitely.
 */
static void lm8323_write_pwm(struct lm8323_pwm *pwm, int kill,
			     int len, const u16 *cmds)
{
	int i;

	for (i = 0; i < len; i++)
		lm8323_write_pwm_one(pwm, i, cmds[i]);

	lm8323_write_pwm_one(pwm, i++, PWM_END(kill));
	lm8323_write(pwm->chip, 2, LM8323_CMD_START_PWM, pwm->id);
	pwm->running = true;
}

static void lm8323_pwm_work(struct work_struct *work)
{
	struct lm8323_pwm *pwm = work_to_pwm(work);
	int div512, perstep, steps, hz, up, kill;
	u16 pwm_cmds[3];
	int num_cmds = 0;

	mutex_lock(&pwm->lock);

	/*
	 * Do nothing if we're already at the requested level,
	 * or previous setting is not yet complete. In the latter
	 * case we will be called again when the previous PWM script
	 * finishes.
	 */
	if (pwm->running || pwm->desired_brightness == pwm->brightness)
		goto out;

	kill = (pwm->desired_brightness == 0);
	up = (pwm->desired_brightness > pwm->brightness);
	steps = abs(pwm->desired_brightness - pwm->brightness);

	/*
	 * Convert time (in ms) into a divisor (512 or 16 on a refclk of
	 * 32768Hz), and number of ticks per step.
	 */
	if ((pwm->fade_time / steps) > (32768 / 512)) {
		div512 = 1;
		hz = 32768 / 512;
	} else {
		div512 = 0;
		hz = 32768 / 16;
	}

	perstep = (hz * pwm->fade_time) / (steps * 1000);

	if (perstep == 0)
		perstep = 1;
	else if (perstep > 63)
		perstep = 63;

	while (steps) {
		int s;

		s = min(126, steps);
		pwm_cmds[num_cmds++] = PWM_RAMP(div512, perstep, s, up);
		steps -= s;
	}

	lm8323_write_pwm(pwm, kill, num_cmds, pwm_cmds);
	pwm->brightness = pwm->desired_brightness;

 out:
	mutex_unlock(&pwm->lock);
}

static void lm8323_pwm_set_brightness(struct led_classdev *led_cdev,
				      enum led_brightness brightness)
{
	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
	struct lm8323_chip *lm = pwm->chip;

	mutex_lock(&pwm->lock);
	pwm->desired_brightness = brightness;
	mutex_unlock(&pwm->lock);

	if (in_interrupt()) {
		schedule_work(&pwm->work);
	} else {
		/*
		 * Schedule PWM work as usual unless we are going into suspend
		 */
		mutex_lock(&lm->lock);
		if (likely(!lm->pm_suspend))
			schedule_work(&pwm->work);
		else
			lm8323_pwm_work(&pwm->work);
		mutex_unlock(&lm->lock);
	}
}

static ssize_t lm8323_pwm_show_time(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);

	return sprintf(buf, "%d\n", pwm->fade_time);
}

static ssize_t lm8323_pwm_store_time(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t len)
{
	struct led_classdev *led_cdev = dev_get_drvdata(dev);
	struct lm8323_pwm *pwm = cdev_to_pwm(led_cdev);
	int ret;
	unsigned long time;

	ret = strict_strtoul(buf, 10, &time);
	/* Numbers only, please. */
	if (ret)
		return -EINVAL;

	pwm->fade_time = time;

	return strlen(buf);
}
static DEVICE_ATTR(time, 0644, lm8323_pwm_show_time, lm8323_pwm_store_time);

static int init_pwm(struct lm8323_chip *lm, int id, struct device *dev,
		    const char *name)
{
	struct lm8323_pwm *pwm;

	BUG_ON(id > 3);

	pwm = &lm->pwm[id - 1];

	pwm->id = id;
	pwm->fade_time = 0;
	pwm->brightness = 0;
	pwm->desired_brightness = 0;
	pwm->running = false;
	pwm->enabled = false;
	INIT_WORK(&pwm->work, lm8323_pwm_work);
	mutex_init(&pwm->lock);
	pwm->chip = lm;

	if (name) {
		pwm->cdev.name = name;
		pwm->cdev.brightness_set = lm8323_pwm_set_brightness;
		if (led_classdev_register(dev, &pwm->cdev) < 0) {
			dev_err(dev, "couldn't register PWM %d\n", id);
			return -1;
		}
		if (device_create_file(pwm->cdev.dev,
					&dev_attr_time) < 0) {
			dev_err(dev, "couldn't register time attribute\n");
			led_classdev_unregister(&pwm->cdev);
			return -1;
		}
		pwm->enabled = true;
	}

	return 0;
}

static struct i2c_driver lm8323_i2c_driver;

static ssize_t lm8323_show_disable(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct lm8323_chip *lm = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", !lm->kp_enabled);
}

static ssize_t lm8323_set_disable(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf, size_t count)
{
	struct lm8323_chip *lm = dev_get_drvdata(dev);
	int ret;
	unsigned long i;

	ret = strict_strtoul(buf, 10, &i);

	mutex_lock(&lm->lock);
	lm->kp_enabled = !i;
	mutex_unlock(&lm->lock);

	return count;
}
static DEVICE_ATTR(disable_kp, 0644, lm8323_show_disable, lm8323_set_disable);

static int __devinit lm8323_probe(struct i2c_client *client,
				  const struct i2c_device_id *id)
{
	struct lm8323_platform_data *pdata = client->dev.platform_data;
	struct input_dev *idev;
	struct lm8323_chip *lm;
	int pwm;
	int i, err;
	unsigned long tmo;
	u8 data[2];

	if (!pdata || !pdata->size_x || !pdata->size_y) {
		dev_err(&client->dev, "missing platform_data\n");
		return -EINVAL;
	}

	if (pdata->size_x > 8) {
		dev_err(&client->dev, "invalid x size %d specified\n",
			pdata->size_x);
		return -EINVAL;
	}

	if (pdata->size_y > 12) {
		dev_err(&client->dev, "invalid y size %d specified\n",
			pdata->size_y);
		return -EINVAL;
	}

	lm = kzalloc(sizeof *lm, GFP_KERNEL);
	idev = input_allocate_device();
	if (!lm || !idev) {
		err = -ENOMEM;
		goto fail1;
	}

	lm->client = client;
	lm->idev = idev;
	mutex_init(&lm->lock);

	lm->size_x = pdata->size_x;
	lm->size_y = pdata->size_y;
	dev_vdbg(&client->dev, "Keypad size: %d x %d\n",
		 lm->size_x, lm->size_y);

	lm->debounce_time = pdata->debounce_time;
	lm->active_time = pdata->active_time;

	lm8323_reset(lm);

	/* Nothing's set up to service the IRQ yet, so just spin for max.
	 * 100ms until we can configure. */
	tmo = jiffies + msecs_to_jiffies(100);
	while (lm8323_read(lm, LM8323_CMD_READ_INT, data, 1) == 1) {
		if (data[0] & INT_NOINIT)
			break;

		if (time_after(jiffies, tmo)) {
			dev_err(&client->dev,
				"timeout waiting for initialisation\n");
			break;
		}

		msleep(1);
	}

	lm8323_configure(lm);

	/* If a true probe check the device */
	if (lm8323_read_id(lm, data) != 0) {
		dev_err(&client->dev, "device not found\n");
		err = -ENODEV;
		goto fail1;
	}

	for (pwm = 0; pwm < LM8323_NUM_PWMS; pwm++) {
		err = init_pwm(lm, pwm + 1, &client->dev,
			       pdata->pwm_names[pwm]);
		if (err < 0)
			goto fail2;
	}

	lm->kp_enabled = true;
	err = device_create_file(&client->dev, &dev_attr_disable_kp);
	if (err < 0)
		goto fail2;

	idev->name = pdata->name ? : "LM8323 keypad";
	snprintf(lm->phys, sizeof(lm->phys),
		 "%s/input-kp", dev_name(&client->dev));
	idev->phys = lm->phys;

	idev->evbit[0] = BIT(EV_KEY) | BIT(EV_MSC);
	__set_bit(MSC_SCAN, idev->mscbit);
	for (i = 0; i < LM8323_KEYMAP_SIZE; i++) {
		__set_bit(pdata->keymap[i], idev->keybit);
		lm->keymap[i] = pdata->keymap[i];
	}
	__clear_bit(KEY_RESERVED, idev->keybit);

	if (pdata->repeat)
		__set_bit(EV_REP, idev->evbit);

	err = input_register_device(idev);
	if (err) {
		dev_dbg(&client->dev, "error registering input device\n");
		goto fail3;
	}

	err = request_threaded_irq(client->irq, NULL, lm8323_irq,
			  IRQF_TRIGGER_LOW|IRQF_ONESHOT, "lm8323", lm);
	if (err) {
		dev_err(&client->dev, "could not get IRQ %d\n", client->irq);
		goto fail4;
	}

	i2c_set_clientdata(client, lm);

	device_init_wakeup(&client->dev, 1);
	enable_irq_wake(client->irq);

	return 0;

fail4:
	input_unregister_device(idev);
	idev = NULL;
fail3:
	device_remove_file(&client->dev, &dev_attr_disable_kp);
fail2:
	while (--pwm >= 0)
		if (lm->pwm[pwm].enabled) {
			device_remove_file(lm->pwm[pwm].cdev.dev,
					   &dev_attr_time);
			led_classdev_unregister(&lm->pwm[pwm].cdev);
		}
fail1:
	input_free_device(idev);
	kfree(lm);
	return err;
}

static int __devexit lm8323_remove(struct i2c_client *client)
{
	struct lm8323_chip *lm = i2c_get_clientdata(client);
	int i;

	disable_irq_wake(client->irq);
	free_irq(client->irq, lm);

	input_unregister_device(lm->idev);

	device_remove_file(&lm->client->dev, &dev_attr_disable_kp);

	for (i = 0; i < 3; i++)
		if (lm->pwm[i].enabled) {
			device_remove_file(lm->pwm[i].cdev.dev, &dev_attr_time);
			led_classdev_unregister(&lm->pwm[i].cdev);
		}

	kfree(lm);

	return 0;
}

#ifdef CONFIG_PM_SLEEP
/*
 * We don't need to explicitly suspend the chip, as it already switches off
 * when there's no activity.
 */
static int lm8323_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm8323_chip *lm = i2c_get_clientdata(client);
	int i;

	irq_set_irq_wake(client->irq, 0);
	disable_irq(client->irq);

	mutex_lock(&lm->lock);
	lm->pm_suspend = true;
	mutex_unlock(&lm->lock);

	for (i = 0; i < 3; i++)
		if (lm->pwm[i].enabled)
			led_classdev_suspend(&lm->pwm[i].cdev);

	return 0;
}

static int lm8323_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm8323_chip *lm = i2c_get_clientdata(client);
	int i;

	mutex_lock(&lm->lock);
	lm->pm_suspend = false;
	mutex_unlock(&lm->lock);

	for (i = 0; i < 3; i++)
		if (lm->pwm[i].enabled)
			led_classdev_resume(&lm->pwm[i].cdev);

	enable_irq(client->irq);
	irq_set_irq_wake(client->irq, 1);

	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(lm8323_pm_ops, lm8323_suspend, lm8323_resume);

static const struct i2c_device_id lm8323_id[] = {
	{ "lm8323", 0 },
	{ }
};

static struct i2c_driver lm8323_i2c_driver = {
	.driver = {
		.name	= "lm8323",
		.pm	= &lm8323_pm_ops,
	},
	.probe		= lm8323_probe,
	.remove		= __devexit_p(lm8323_remove),
	.id_table	= lm8323_id,
};
MODULE_DEVICE_TABLE(i2c, lm8323_id);

static int __init lm8323_init(void)
{
	return i2c_add_driver(&lm8323_i2c_driver);
}
module_init(lm8323_init);

static void __exit lm8323_exit(void)
{
	i2c_del_driver(&lm8323_i2c_driver);
}
module_exit(lm8323_exit);

MODULE_AUTHOR("Timo O. Karjalainen <timo.o.karjalainen@nokia.com>");
MODULE_AUTHOR("Daniel Stone");
MODULE_AUTHOR("Felipe Balbi <felipe.balbi@nokia.com>");
MODULE_DESCRIPTION("LM8323 keypad driver");
MODULE_LICENSE("GPL");