summaryrefslogtreecommitdiff
path: root/drivers/video/s3c2410fb.c
blob: 0aa13761de6ec3168c38569dd2a9ee479689cdfb (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
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
/* linux/drivers/video/s3c2410fb.c
 *	Copyright (c) 2004,2005 Arnaud Patard
 *	Copyright (c) 2004-2008 Ben Dooks
 *
 * S3C2410 LCD Framebuffer Driver
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive for
 * more details.
 *
 * Driver based on skeletonfb.c, sa1100fb.c and others.
*/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/cpufreq.h>

#include <asm/io.h>
#include <asm/div64.h>

#include <asm/mach/map.h>
#include <mach/regs-lcd.h>
#include <mach/regs-gpio.h>
#include <mach/fb.h>

#ifdef CONFIG_PM
#include <linux/pm.h>
#endif

#include "s3c2410fb.h"

/* Debugging stuff */
#ifdef CONFIG_FB_S3C2410_DEBUG
static int debug	= 1;
#else
static int debug	= 0;
#endif

#define dprintk(msg...)	if (debug) { printk(KERN_DEBUG "s3c2410fb: " msg); }

/* useful functions */

static int is_s3c2412(struct s3c2410fb_info *fbi)
{
	return (fbi->drv_type == DRV_S3C2412);
}

/* s3c2410fb_set_lcdaddr
 *
 * initialise lcd controller address pointers
 */
static void s3c2410fb_set_lcdaddr(struct fb_info *info)
{
	unsigned long saddr1, saddr2, saddr3;
	struct s3c2410fb_info *fbi = info->par;
	void __iomem *regs = fbi->io;

	saddr1  = info->fix.smem_start >> 1;
	saddr2  = info->fix.smem_start;
	saddr2 += info->fix.line_length * info->var.yres;
	saddr2 >>= 1;

	saddr3 = S3C2410_OFFSIZE(0) |
		 S3C2410_PAGEWIDTH((info->fix.line_length / 2) & 0x3ff);

	dprintk("LCDSADDR1 = 0x%08lx\n", saddr1);
	dprintk("LCDSADDR2 = 0x%08lx\n", saddr2);
	dprintk("LCDSADDR3 = 0x%08lx\n", saddr3);

	writel(saddr1, regs + S3C2410_LCDSADDR1);
	writel(saddr2, regs + S3C2410_LCDSADDR2);
	writel(saddr3, regs + S3C2410_LCDSADDR3);
}

/* s3c2410fb_calc_pixclk()
 *
 * calculate divisor for clk->pixclk
 */
static unsigned int s3c2410fb_calc_pixclk(struct s3c2410fb_info *fbi,
					  unsigned long pixclk)
{
	unsigned long clk = fbi->clk_rate;
	unsigned long long div;

	/* pixclk is in picoseconds, our clock is in Hz
	 *
	 * Hz -> picoseconds is / 10^-12
	 */

	div = (unsigned long long)clk * pixclk;
	div >>= 12;			/* div / 2^12 */
	do_div(div, 625 * 625UL * 625); /* div / 5^12 */

	dprintk("pixclk %ld, divisor is %ld\n", pixclk, (long)div);
	return div;
}

/*
 *	s3c2410fb_check_var():
 *	Get the video params out of 'var'. If a value doesn't fit, round it up,
 *	if it's too big, return -EINVAL.
 *
 */
static int s3c2410fb_check_var(struct fb_var_screeninfo *var,
			       struct fb_info *info)
{
	struct s3c2410fb_info *fbi = info->par;
	struct s3c2410fb_mach_info *mach_info = fbi->dev->platform_data;
	struct s3c2410fb_display *display = NULL;
	struct s3c2410fb_display *default_display = mach_info->displays +
						    mach_info->default_display;
	int type = default_display->type;
	unsigned i;

	dprintk("check_var(var=%p, info=%p)\n", var, info);

	/* validate x/y resolution */
	/* choose default mode if possible */
	if (var->yres == default_display->yres &&
	    var->xres == default_display->xres &&
	    var->bits_per_pixel == default_display->bpp)
		display = default_display;
	else
		for (i = 0; i < mach_info->num_displays; i++)
			if (type == mach_info->displays[i].type &&
			    var->yres == mach_info->displays[i].yres &&
			    var->xres == mach_info->displays[i].xres &&
			    var->bits_per_pixel == mach_info->displays[i].bpp) {
				display = mach_info->displays + i;
				break;
			}

	if (!display) {
		dprintk("wrong resolution or depth %dx%d at %d bpp\n",
			var->xres, var->yres, var->bits_per_pixel);
		return -EINVAL;
	}

	/* it is always the size as the display */
	var->xres_virtual = display->xres;
	var->yres_virtual = display->yres;
	var->height = display->height;
	var->width = display->width;

	/* copy lcd settings */
	var->pixclock = display->pixclock;
	var->left_margin = display->left_margin;
	var->right_margin = display->right_margin;
	var->upper_margin = display->upper_margin;
	var->lower_margin = display->lower_margin;
	var->vsync_len = display->vsync_len;
	var->hsync_len = display->hsync_len;

	fbi->regs.lcdcon5 = display->lcdcon5;
	/* set display type */
	fbi->regs.lcdcon1 = display->type;

	var->transp.offset = 0;
	var->transp.length = 0;
	/* set r/g/b positions */
	switch (var->bits_per_pixel) {
	case 1:
	case 2:
	case 4:
		var->red.offset	= 0;
		var->red.length	= var->bits_per_pixel;
		var->green	= var->red;
		var->blue	= var->red;
		break;
	case 8:
		if (display->type != S3C2410_LCDCON1_TFT) {
			/* 8 bpp 332 */
			var->red.length		= 3;
			var->red.offset		= 5;
			var->green.length	= 3;
			var->green.offset	= 2;
			var->blue.length	= 2;
			var->blue.offset	= 0;
		} else {
			var->red.offset		= 0;
			var->red.length		= 8;
			var->green		= var->red;
			var->blue		= var->red;
		}
		break;
	case 12:
		/* 12 bpp 444 */
		var->red.length		= 4;
		var->red.offset		= 8;
		var->green.length	= 4;
		var->green.offset	= 4;
		var->blue.length	= 4;
		var->blue.offset	= 0;
		break;

	default:
	case 16:
		if (display->lcdcon5 & S3C2410_LCDCON5_FRM565) {
			/* 16 bpp, 565 format */
			var->red.offset		= 11;
			var->green.offset	= 5;
			var->blue.offset	= 0;
			var->red.length		= 5;
			var->green.length	= 6;
			var->blue.length	= 5;
		} else {
			/* 16 bpp, 5551 format */
			var->red.offset		= 11;
			var->green.offset	= 6;
			var->blue.offset	= 1;
			var->red.length		= 5;
			var->green.length	= 5;
			var->blue.length	= 5;
		}
		break;
	case 32:
		/* 24 bpp 888 and 8 dummy */
		var->red.length		= 8;
		var->red.offset		= 16;
		var->green.length	= 8;
		var->green.offset	= 8;
		var->blue.length	= 8;
		var->blue.offset	= 0;
		break;
	}
	return 0;
}

/* s3c2410fb_calculate_stn_lcd_regs
 *
 * calculate register values from var settings
 */
static void s3c2410fb_calculate_stn_lcd_regs(const struct fb_info *info,
					     struct s3c2410fb_hw *regs)
{
	const struct s3c2410fb_info *fbi = info->par;
	const struct fb_var_screeninfo *var = &info->var;
	int type = regs->lcdcon1 & ~S3C2410_LCDCON1_TFT;
	int hs = var->xres >> 2;
	unsigned wdly = (var->left_margin >> 4) - 1;
	unsigned wlh = (var->hsync_len >> 4) - 1;

	if (type != S3C2410_LCDCON1_STN4)
		hs >>= 1;

	switch (var->bits_per_pixel) {
	case 1:
		regs->lcdcon1 |= S3C2410_LCDCON1_STN1BPP;
		break;
	case 2:
		regs->lcdcon1 |= S3C2410_LCDCON1_STN2GREY;
		break;
	case 4:
		regs->lcdcon1 |= S3C2410_LCDCON1_STN4GREY;
		break;
	case 8:
		regs->lcdcon1 |= S3C2410_LCDCON1_STN8BPP;
		hs *= 3;
		break;
	case 12:
		regs->lcdcon1 |= S3C2410_LCDCON1_STN12BPP;
		hs *= 3;
		break;

	default:
		/* invalid pixel depth */
		dev_err(fbi->dev, "invalid bpp %d\n",
			var->bits_per_pixel);
	}
	/* update X/Y info */
	dprintk("setting horz: lft=%d, rt=%d, sync=%d\n",
		var->left_margin, var->right_margin, var->hsync_len);

	regs->lcdcon2 = S3C2410_LCDCON2_LINEVAL(var->yres - 1);

	if (wdly > 3)
		wdly = 3;

	if (wlh > 3)
		wlh = 3;

	regs->lcdcon3 =	S3C2410_LCDCON3_WDLY(wdly) |
			S3C2410_LCDCON3_LINEBLANK(var->right_margin / 8) |
			S3C2410_LCDCON3_HOZVAL(hs - 1);

	regs->lcdcon4 = S3C2410_LCDCON4_WLH(wlh);
}

/* s3c2410fb_calculate_tft_lcd_regs
 *
 * calculate register values from var settings
 */
static void s3c2410fb_calculate_tft_lcd_regs(const struct fb_info *info,
					     struct s3c2410fb_hw *regs)
{
	const struct s3c2410fb_info *fbi = info->par;
	const struct fb_var_screeninfo *var = &info->var;

	switch (var->bits_per_pixel) {
	case 1:
		regs->lcdcon1 |= S3C2410_LCDCON1_TFT1BPP;
		break;
	case 2:
		regs->lcdcon1 |= S3C2410_LCDCON1_TFT2BPP;
		break;
	case 4:
		regs->lcdcon1 |= S3C2410_LCDCON1_TFT4BPP;
		break;
	case 8:
		regs->lcdcon1 |= S3C2410_LCDCON1_TFT8BPP;
		regs->lcdcon5 |= S3C2410_LCDCON5_BSWP |
				 S3C2410_LCDCON5_FRM565;
		regs->lcdcon5 &= ~S3C2410_LCDCON5_HWSWP;
		break;
	case 16:
		regs->lcdcon1 |= S3C2410_LCDCON1_TFT16BPP;
		regs->lcdcon5 &= ~S3C2410_LCDCON5_BSWP;
		regs->lcdcon5 |= S3C2410_LCDCON5_HWSWP;
		break;
	case 32:
		regs->lcdcon1 |= S3C2410_LCDCON1_TFT24BPP;
		regs->lcdcon5 &= ~(S3C2410_LCDCON5_BSWP |
				   S3C2410_LCDCON5_HWSWP |
				   S3C2410_LCDCON5_BPP24BL);
		break;
	default:
		/* invalid pixel depth */
		dev_err(fbi->dev, "invalid bpp %d\n",
			var->bits_per_pixel);
	}
	/* update X/Y info */
	dprintk("setting vert: up=%d, low=%d, sync=%d\n",
		var->upper_margin, var->lower_margin, var->vsync_len);

	dprintk("setting horz: lft=%d, rt=%d, sync=%d\n",
		var->left_margin, var->right_margin, var->hsync_len);

	regs->lcdcon2 = S3C2410_LCDCON2_LINEVAL(var->yres - 1) |
			S3C2410_LCDCON2_VBPD(var->upper_margin - 1) |
			S3C2410_LCDCON2_VFPD(var->lower_margin - 1) |
			S3C2410_LCDCON2_VSPW(var->vsync_len - 1);

	regs->lcdcon3 = S3C2410_LCDCON3_HBPD(var->right_margin - 1) |
			S3C2410_LCDCON3_HFPD(var->left_margin - 1) |
			S3C2410_LCDCON3_HOZVAL(var->xres - 1);

	regs->lcdcon4 = S3C2410_LCDCON4_HSPW(var->hsync_len - 1);
}

/* s3c2410fb_activate_var
 *
 * activate (set) the controller from the given framebuffer
 * information
 */
static void s3c2410fb_activate_var(struct fb_info *info)
{
	struct s3c2410fb_info *fbi = info->par;
	void __iomem *regs = fbi->io;
	int type = fbi->regs.lcdcon1 & S3C2410_LCDCON1_TFT;
	struct fb_var_screeninfo *var = &info->var;
	int clkdiv;

	clkdiv = DIV_ROUND_UP(s3c2410fb_calc_pixclk(fbi, var->pixclock), 2);

	dprintk("%s: var->xres  = %d\n", __func__, var->xres);
	dprintk("%s: var->yres  = %d\n", __func__, var->yres);
	dprintk("%s: var->bpp   = %d\n", __func__, var->bits_per_pixel);

	if (type == S3C2410_LCDCON1_TFT) {
		s3c2410fb_calculate_tft_lcd_regs(info, &fbi->regs);
		--clkdiv;
		if (clkdiv < 0)
			clkdiv = 0;
	} else {
		s3c2410fb_calculate_stn_lcd_regs(info, &fbi->regs);
		if (clkdiv < 2)
			clkdiv = 2;
	}

	fbi->regs.lcdcon1 |=  S3C2410_LCDCON1_CLKVAL(clkdiv);

	/* write new registers */

	dprintk("new register set:\n");
	dprintk("lcdcon[1] = 0x%08lx\n", fbi->regs.lcdcon1);
	dprintk("lcdcon[2] = 0x%08lx\n", fbi->regs.lcdcon2);
	dprintk("lcdcon[3] = 0x%08lx\n", fbi->regs.lcdcon3);
	dprintk("lcdcon[4] = 0x%08lx\n", fbi->regs.lcdcon4);
	dprintk("lcdcon[5] = 0x%08lx\n", fbi->regs.lcdcon5);

	writel(fbi->regs.lcdcon1 & ~S3C2410_LCDCON1_ENVID,
		regs + S3C2410_LCDCON1);
	writel(fbi->regs.lcdcon2, regs + S3C2410_LCDCON2);
	writel(fbi->regs.lcdcon3, regs + S3C2410_LCDCON3);
	writel(fbi->regs.lcdcon4, regs + S3C2410_LCDCON4);
	writel(fbi->regs.lcdcon5, regs + S3C2410_LCDCON5);

	/* set lcd address pointers */
	s3c2410fb_set_lcdaddr(info);

	fbi->regs.lcdcon1 |= S3C2410_LCDCON1_ENVID,
	writel(fbi->regs.lcdcon1, regs + S3C2410_LCDCON1);
}

/*
 *      s3c2410fb_set_par - Alters the hardware state.
 *      @info: frame buffer structure that represents a single frame buffer
 *
 */
static int s3c2410fb_set_par(struct fb_info *info)
{
	struct fb_var_screeninfo *var = &info->var;

	switch (var->bits_per_pixel) {
	case 32:
	case 16:
	case 12:
		info->fix.visual = FB_VISUAL_TRUECOLOR;
		break;
	case 1:
		info->fix.visual = FB_VISUAL_MONO01;
		break;
	default:
		info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
		break;
	}

	info->fix.line_length = (var->xres_virtual * var->bits_per_pixel) / 8;

	/* activate this new configuration */

	s3c2410fb_activate_var(info);
	return 0;
}

static void schedule_palette_update(struct s3c2410fb_info *fbi,
				    unsigned int regno, unsigned int val)
{
	unsigned long flags;
	unsigned long irqen;
	void __iomem *irq_base = fbi->irq_base;

	local_irq_save(flags);

	fbi->palette_buffer[regno] = val;

	if (!fbi->palette_ready) {
		fbi->palette_ready = 1;

		/* enable IRQ */
		irqen = readl(irq_base + S3C24XX_LCDINTMSK);
		irqen &= ~S3C2410_LCDINT_FRSYNC;
		writel(irqen, irq_base + S3C24XX_LCDINTMSK);
	}

	local_irq_restore(flags);
}

/* from pxafb.c */
static inline unsigned int chan_to_field(unsigned int chan,
					 struct fb_bitfield *bf)
{
	chan &= 0xffff;
	chan >>= 16 - bf->length;
	return chan << bf->offset;
}

static int s3c2410fb_setcolreg(unsigned regno,
			       unsigned red, unsigned green, unsigned blue,
			       unsigned transp, struct fb_info *info)
{
	struct s3c2410fb_info *fbi = info->par;
	void __iomem *regs = fbi->io;
	unsigned int val;

	/* dprintk("setcol: regno=%d, rgb=%d,%d,%d\n",
		   regno, red, green, blue); */

	switch (info->fix.visual) {
	case FB_VISUAL_TRUECOLOR:
		/* true-colour, use pseudo-palette */

		if (regno < 16) {
			u32 *pal = info->pseudo_palette;

			val  = chan_to_field(red,   &info->var.red);
			val |= chan_to_field(green, &info->var.green);
			val |= chan_to_field(blue,  &info->var.blue);

			pal[regno] = val;
		}
		break;

	case FB_VISUAL_PSEUDOCOLOR:
		if (regno < 256) {
			/* currently assume RGB 5-6-5 mode */

			val  = (red   >>  0) & 0xf800;
			val |= (green >>  5) & 0x07e0;
			val |= (blue  >> 11) & 0x001f;

			writel(val, regs + S3C2410_TFTPAL(regno));
			schedule_palette_update(fbi, regno, val);
		}

		break;

	default:
		return 1;	/* unknown type */
	}

	return 0;
}

/* s3c2410fb_lcd_enable
 *
 * shutdown the lcd controller
 */
static void s3c2410fb_lcd_enable(struct s3c2410fb_info *fbi, int enable)
{
	unsigned long flags;

	local_irq_save(flags);

	if (enable)
		fbi->regs.lcdcon1 |= S3C2410_LCDCON1_ENVID;
	else
		fbi->regs.lcdcon1 &= ~S3C2410_LCDCON1_ENVID;

	writel(fbi->regs.lcdcon1, fbi->io + S3C2410_LCDCON1);

	local_irq_restore(flags);
}


/*
 *      s3c2410fb_blank
 *	@blank_mode: the blank mode we want.
 *	@info: frame buffer structure that represents a single frame buffer
 *
 *	Blank the screen if blank_mode != 0, else unblank. Return 0 if
 *	blanking succeeded, != 0 if un-/blanking failed due to e.g. a
 *	video mode which doesn't support it. Implements VESA suspend
 *	and powerdown modes on hardware that supports disabling hsync/vsync:
 *
 *	Returns negative errno on error, or zero on success.
 *
 */
static int s3c2410fb_blank(int blank_mode, struct fb_info *info)
{
	struct s3c2410fb_info *fbi = info->par;
	void __iomem *tpal_reg = fbi->io;

	dprintk("blank(mode=%d, info=%p)\n", blank_mode, info);

	tpal_reg += is_s3c2412(fbi) ? S3C2412_TPAL : S3C2410_TPAL;

	if (blank_mode == FB_BLANK_POWERDOWN) {
		s3c2410fb_lcd_enable(fbi, 0);
	} else {
		s3c2410fb_lcd_enable(fbi, 1);
	}

	if (blank_mode == FB_BLANK_UNBLANK)
		writel(0x0, tpal_reg);
	else {
		dprintk("setting TPAL to output 0x000000\n");
		writel(S3C2410_TPAL_EN, tpal_reg);
	}

	return 0;
}

static int s3c2410fb_debug_show(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%s\n", debug ? "on" : "off");
}

static int s3c2410fb_debug_store(struct device *dev,
				 struct device_attribute *attr,
				 const char *buf, size_t len)
{
	if (len < 1)
		return -EINVAL;

	if (strnicmp(buf, "on", 2) == 0 ||
	    strnicmp(buf, "1", 1) == 0) {
		debug = 1;
		printk(KERN_DEBUG "s3c2410fb: Debug On");
	} else if (strnicmp(buf, "off", 3) == 0 ||
		   strnicmp(buf, "0", 1) == 0) {
		debug = 0;
		printk(KERN_DEBUG "s3c2410fb: Debug Off");
	} else {
		return -EINVAL;
	}

	return len;
}

static DEVICE_ATTR(debug, 0666, s3c2410fb_debug_show, s3c2410fb_debug_store);

static struct fb_ops s3c2410fb_ops = {
	.owner		= THIS_MODULE,
	.fb_check_var	= s3c2410fb_check_var,
	.fb_set_par	= s3c2410fb_set_par,
	.fb_blank	= s3c2410fb_blank,
	.fb_setcolreg	= s3c2410fb_setcolreg,
	.fb_fillrect	= cfb_fillrect,
	.fb_copyarea	= cfb_copyarea,
	.fb_imageblit	= cfb_imageblit,
};

/*
 * s3c2410fb_map_video_memory():
 *	Allocates the DRAM memory for the frame buffer.  This buffer is
 *	remapped into a non-cached, non-buffered, memory region to
 *	allow palette and pixel writes to occur without flushing the
 *	cache.  Once this area is remapped, all virtual memory
 *	access to the video memory should occur at the new region.
 */
static int __devinit s3c2410fb_map_video_memory(struct fb_info *info)
{
	struct s3c2410fb_info *fbi = info->par;
	dma_addr_t map_dma;
	unsigned map_size = PAGE_ALIGN(info->fix.smem_len);

	dprintk("map_video_memory(fbi=%p) map_size %u\n", fbi, map_size);

	info->screen_base = dma_alloc_writecombine(fbi->dev, map_size,
						   &map_dma, GFP_KERNEL);

	if (info->screen_base) {
		/* prevent initial garbage on screen */
		dprintk("map_video_memory: clear %p:%08x\n",
			info->screen_base, map_size);
		memset(info->screen_base, 0x00, map_size);

		info->fix.smem_start = map_dma;

		dprintk("map_video_memory: dma=%08lx cpu=%p size=%08x\n",
			info->fix.smem_start, info->screen_base, map_size);
	}

	return info->screen_base ? 0 : -ENOMEM;
}

static inline void s3c2410fb_unmap_video_memory(struct fb_info *info)
{
	struct s3c2410fb_info *fbi = info->par;

	dma_free_writecombine(fbi->dev, PAGE_ALIGN(info->fix.smem_len),
			      info->screen_base, info->fix.smem_start);
}

static inline void modify_gpio(void __iomem *reg,
			       unsigned long set, unsigned long mask)
{
	unsigned long tmp;

	tmp = readl(reg) & ~mask;
	writel(tmp | set, reg);
}

/*
 * s3c2410fb_init_registers - Initialise all LCD-related registers
 */
static int s3c2410fb_init_registers(struct fb_info *info)
{
	struct s3c2410fb_info *fbi = info->par;
	struct s3c2410fb_mach_info *mach_info = fbi->dev->platform_data;
	unsigned long flags;
	void __iomem *regs = fbi->io;
	void __iomem *tpal;
	void __iomem *lpcsel;

	if (is_s3c2412(fbi)) {
		tpal = regs + S3C2412_TPAL;
		lpcsel = regs + S3C2412_TCONSEL;
	} else {
		tpal = regs + S3C2410_TPAL;
		lpcsel = regs + S3C2410_LPCSEL;
	}

	/* Initialise LCD with values from haret */

	local_irq_save(flags);

	/* modify the gpio(s) with interrupts set (bjd) */

	modify_gpio(S3C2410_GPCUP,  mach_info->gpcup,  mach_info->gpcup_mask);
	modify_gpio(S3C2410_GPCCON, mach_info->gpccon, mach_info->gpccon_mask);
	modify_gpio(S3C2410_GPDUP,  mach_info->gpdup,  mach_info->gpdup_mask);
	modify_gpio(S3C2410_GPDCON, mach_info->gpdcon, mach_info->gpdcon_mask);

	local_irq_restore(flags);

	dprintk("LPCSEL    = 0x%08lx\n", mach_info->lpcsel);
	writel(mach_info->lpcsel, lpcsel);

	dprintk("replacing TPAL %08x\n", readl(tpal));

	/* ensure temporary palette disabled */
	writel(0x00, tpal);

	return 0;
}

static void s3c2410fb_write_palette(struct s3c2410fb_info *fbi)
{
	unsigned int i;
	void __iomem *regs = fbi->io;

	fbi->palette_ready = 0;

	for (i = 0; i < 256; i++) {
		unsigned long ent = fbi->palette_buffer[i];
		if (ent == PALETTE_BUFF_CLEAR)
			continue;

		writel(ent, regs + S3C2410_TFTPAL(i));

		/* it seems the only way to know exactly
		 * if the palette wrote ok, is to check
		 * to see if the value verifies ok
		 */

		if (readw(regs + S3C2410_TFTPAL(i)) == ent)
			fbi->palette_buffer[i] = PALETTE_BUFF_CLEAR;
		else
			fbi->palette_ready = 1;   /* retry */
	}
}

static irqreturn_t s3c2410fb_irq(int irq, void *dev_id)
{
	struct s3c2410fb_info *fbi = dev_id;
	void __iomem *irq_base = fbi->irq_base;
	unsigned long lcdirq = readl(irq_base + S3C24XX_LCDINTPND);

	if (lcdirq & S3C2410_LCDINT_FRSYNC) {
		if (fbi->palette_ready)
			s3c2410fb_write_palette(fbi);

		writel(S3C2410_LCDINT_FRSYNC, irq_base + S3C24XX_LCDINTPND);
		writel(S3C2410_LCDINT_FRSYNC, irq_base + S3C24XX_LCDSRCPND);
	}

	return IRQ_HANDLED;
}

#ifdef CONFIG_CPU_FREQ

static int s3c2410fb_cpufreq_transition(struct notifier_block *nb,
					unsigned long val, void *data)
{
	struct cpufreq_freqs *freqs = data;
	struct s3c2410fb_info *info;
	struct fb_info *fbinfo;
	long delta_f;

	info = container_of(nb, struct s3c2410fb_info, freq_transition);
	fbinfo = platform_get_drvdata(to_platform_device(info->dev));

	/* work out change, <0 for speed-up */
	delta_f = info->clk_rate - clk_get_rate(info->clk);

	if ((val == CPUFREQ_POSTCHANGE && delta_f > 0) ||
	    (val == CPUFREQ_PRECHANGE && delta_f < 0)) {
		info->clk_rate = clk_get_rate(info->clk);
		s3c2410fb_activate_var(fbinfo);
	}

	return 0;
}

static inline int s3c2410fb_cpufreq_register(struct s3c2410fb_info *info)
{
	info->freq_transition.notifier_call = s3c2410fb_cpufreq_transition;

	return cpufreq_register_notifier(&info->freq_transition,
					 CPUFREQ_TRANSITION_NOTIFIER);
}

static inline void s3c2410fb_cpufreq_deregister(struct s3c2410fb_info *info)
{
	cpufreq_unregister_notifier(&info->freq_transition,
				    CPUFREQ_TRANSITION_NOTIFIER);
}

#else
static inline int s3c2410fb_cpufreq_register(struct s3c2410fb_info *info)
{
	return 0;
}

static inline void s3c2410fb_cpufreq_deregister(struct s3c2410fb_info *info)
{
}
#endif


static char driver_name[] = "s3c2410fb";

static int __devinit s3c24xxfb_probe(struct platform_device *pdev,
				  enum s3c_drv_type drv_type)
{
	struct s3c2410fb_info *info;
	struct s3c2410fb_display *display;
	struct fb_info *fbinfo;
	struct s3c2410fb_mach_info *mach_info;
	struct resource *res;
	int ret;
	int irq;
	int i;
	int size;
	u32 lcdcon1;

	mach_info = pdev->dev.platform_data;
	if (mach_info == NULL) {
		dev_err(&pdev->dev,
			"no platform data for lcd, cannot attach\n");
		return -EINVAL;
	}

	if (mach_info->default_display >= mach_info->num_displays) {
		dev_err(&pdev->dev, "default is %d but only %d displays\n",
			mach_info->default_display, mach_info->num_displays);
		return -EINVAL;
	}

	display = mach_info->displays + mach_info->default_display;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0) {
		dev_err(&pdev->dev, "no irq for device\n");
		return -ENOENT;
	}

	fbinfo = framebuffer_alloc(sizeof(struct s3c2410fb_info), &pdev->dev);
	if (!fbinfo)
		return -ENOMEM;

	platform_set_drvdata(pdev, fbinfo);

	info = fbinfo->par;
	info->dev = &pdev->dev;
	info->drv_type = drv_type;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (res == NULL) {
		dev_err(&pdev->dev, "failed to get memory registers\n");
		ret = -ENXIO;
		goto dealloc_fb;
	}

	size = resource_size(res);
	info->mem = request_mem_region(res->start, size, pdev->name);
	if (info->mem == NULL) {
		dev_err(&pdev->dev, "failed to get memory region\n");
		ret = -ENOENT;
		goto dealloc_fb;
	}

	info->io = ioremap(res->start, size);
	if (info->io == NULL) {
		dev_err(&pdev->dev, "ioremap() of registers failed\n");
		ret = -ENXIO;
		goto release_mem;
	}

	info->irq_base = info->io + ((drv_type == DRV_S3C2412) ? S3C2412_LCDINTBASE : S3C2410_LCDINTBASE);

	dprintk("devinit\n");

	strcpy(fbinfo->fix.id, driver_name);

	/* Stop the video */
	lcdcon1 = readl(info->io + S3C2410_LCDCON1);
	writel(lcdcon1 & ~S3C2410_LCDCON1_ENVID, info->io + S3C2410_LCDCON1);

	fbinfo->fix.type	    = FB_TYPE_PACKED_PIXELS;
	fbinfo->fix.type_aux	    = 0;
	fbinfo->fix.xpanstep	    = 0;
	fbinfo->fix.ypanstep	    = 0;
	fbinfo->fix.ywrapstep	    = 0;
	fbinfo->fix.accel	    = FB_ACCEL_NONE;

	fbinfo->var.nonstd	    = 0;
	fbinfo->var.activate	    = FB_ACTIVATE_NOW;
	fbinfo->var.accel_flags     = 0;
	fbinfo->var.vmode	    = FB_VMODE_NONINTERLACED;

	fbinfo->fbops		    = &s3c2410fb_ops;
	fbinfo->flags		    = FBINFO_FLAG_DEFAULT;
	fbinfo->pseudo_palette      = &info->pseudo_pal;

	for (i = 0; i < 256; i++)
		info->palette_buffer[i] = PALETTE_BUFF_CLEAR;

	ret = request_irq(irq, s3c2410fb_irq, IRQF_DISABLED, pdev->name, info);
	if (ret) {
		dev_err(&pdev->dev, "cannot get irq %d - err %d\n", irq, ret);
		ret = -EBUSY;
		goto release_regs;
	}

	info->clk = clk_get(NULL, "lcd");
	if (IS_ERR(info->clk)) {
		printk(KERN_ERR "failed to get lcd clock source\n");
		ret = PTR_ERR(info->clk);
		goto release_irq;
	}

	clk_enable(info->clk);
	dprintk("got and enabled clock\n");

	msleep(1);

	info->clk_rate = clk_get_rate(info->clk);

	/* find maximum required memory size for display */
	for (i = 0; i < mach_info->num_displays; i++) {
		unsigned long smem_len = mach_info->displays[i].xres;

		smem_len *= mach_info->displays[i].yres;
		smem_len *= mach_info->displays[i].bpp;
		smem_len >>= 3;
		if (fbinfo->fix.smem_len < smem_len)
			fbinfo->fix.smem_len = smem_len;
	}

	/* Initialize video memory */
	ret = s3c2410fb_map_video_memory(fbinfo);
	if (ret) {
		printk(KERN_ERR "Failed to allocate video RAM: %d\n", ret);
		ret = -ENOMEM;
		goto release_clock;
	}

	dprintk("got video memory\n");

	fbinfo->var.xres = display->xres;
	fbinfo->var.yres = display->yres;
	fbinfo->var.bits_per_pixel = display->bpp;

	s3c2410fb_init_registers(fbinfo);

	s3c2410fb_check_var(&fbinfo->var, fbinfo);

	ret = s3c2410fb_cpufreq_register(info);
	if (ret < 0) {
		dev_err(&pdev->dev, "Failed to register cpufreq\n");
		goto free_video_memory;
	}

	ret = register_framebuffer(fbinfo);
	if (ret < 0) {
		printk(KERN_ERR "Failed to register framebuffer device: %d\n",
			ret);
		goto free_cpufreq;
	}

	/* create device files */
	ret = device_create_file(&pdev->dev, &dev_attr_debug);
	if (ret) {
		printk(KERN_ERR "failed to add debug attribute\n");
	}

	printk(KERN_INFO "fb%d: %s frame buffer device\n",
		fbinfo->node, fbinfo->fix.id);

	return 0;

 free_cpufreq:
	s3c2410fb_cpufreq_deregister(info);
free_video_memory:
	s3c2410fb_unmap_video_memory(fbinfo);
release_clock:
	clk_disable(info->clk);
	clk_put(info->clk);
release_irq:
	free_irq(irq, info);
release_regs:
	iounmap(info->io);
release_mem:
	release_mem_region(res->start, size);
dealloc_fb:
	platform_set_drvdata(pdev, NULL);
	framebuffer_release(fbinfo);
	return ret;
}

static int __devinit s3c2410fb_probe(struct platform_device *pdev)
{
	return s3c24xxfb_probe(pdev, DRV_S3C2410);
}

static int __devinit s3c2412fb_probe(struct platform_device *pdev)
{
	return s3c24xxfb_probe(pdev, DRV_S3C2412);
}


/*
 *  Cleanup
 */
static int __devexit s3c2410fb_remove(struct platform_device *pdev)
{
	struct fb_info *fbinfo = platform_get_drvdata(pdev);
	struct s3c2410fb_info *info = fbinfo->par;
	int irq;

	unregister_framebuffer(fbinfo);
	s3c2410fb_cpufreq_deregister(info);

	s3c2410fb_lcd_enable(info, 0);
	msleep(1);

	s3c2410fb_unmap_video_memory(fbinfo);

	if (info->clk) {
		clk_disable(info->clk);
		clk_put(info->clk);
		info->clk = NULL;
	}

	irq = platform_get_irq(pdev, 0);
	free_irq(irq, info);

	iounmap(info->io);

	release_mem_region(info->mem->start, resource_size(info->mem));

	platform_set_drvdata(pdev, NULL);
	framebuffer_release(fbinfo);

	return 0;
}

#ifdef CONFIG_PM

/* suspend and resume support for the lcd controller */
static int s3c2410fb_suspend(struct platform_device *dev, pm_message_t state)
{
	struct fb_info	   *fbinfo = platform_get_drvdata(dev);
	struct s3c2410fb_info *info = fbinfo->par;

	s3c2410fb_lcd_enable(info, 0);

	/* sleep before disabling the clock, we need to ensure
	 * the LCD DMA engine is not going to get back on the bus
	 * before the clock goes off again (bjd) */

	msleep(1);
	clk_disable(info->clk);

	return 0;
}

static int s3c2410fb_resume(struct platform_device *dev)
{
	struct fb_info	   *fbinfo = platform_get_drvdata(dev);
	struct s3c2410fb_info *info = fbinfo->par;

	clk_enable(info->clk);
	msleep(1);

	s3c2410fb_init_registers(fbinfo);

	/* re-activate our display after resume */
	s3c2410fb_activate_var(fbinfo);
	s3c2410fb_blank(FB_BLANK_UNBLANK, fbinfo);

	return 0;
}

#else
#define s3c2410fb_suspend NULL
#define s3c2410fb_resume  NULL
#endif

static struct platform_driver s3c2410fb_driver = {
	.probe		= s3c2410fb_probe,
	.remove		= __devexit_p(s3c2410fb_remove),
	.suspend	= s3c2410fb_suspend,
	.resume		= s3c2410fb_resume,
	.driver		= {
		.name	= "s3c2410-lcd",
		.owner	= THIS_MODULE,
	},
};

static struct platform_driver s3c2412fb_driver = {
	.probe		= s3c2412fb_probe,
	.remove		= __devexit_p(s3c2410fb_remove),
	.suspend	= s3c2410fb_suspend,
	.resume		= s3c2410fb_resume,
	.driver		= {
		.name	= "s3c2412-lcd",
		.owner	= THIS_MODULE,
	},
};

int __init s3c2410fb_init(void)
{
	int ret = platform_driver_register(&s3c2410fb_driver);

	if (ret == 0)
		ret = platform_driver_register(&s3c2412fb_driver);

	return ret;
}

static void __exit s3c2410fb_cleanup(void)
{
	platform_driver_unregister(&s3c2410fb_driver);
	platform_driver_unregister(&s3c2412fb_driver);
}

module_init(s3c2410fb_init);
module_exit(s3c2410fb_cleanup);

MODULE_AUTHOR("Arnaud Patard <arnaud.patard@rtp-net.org>, "
	      "Ben Dooks <ben-linux@fluff.org>");
MODULE_DESCRIPTION("Framebuffer driver for the s3c2410");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:s3c2410-lcd");
MODULE_ALIAS("platform:s3c2412-lcd");