aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/video/controlfb.c
blob: 403d17377f8db67fce024dbf52e4091225e6a743 (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
/*
 *  controlfb.c -- frame buffer device for the PowerMac 'control' display
 *
 *  Created 12 July 1998 by Dan Jacobowitz <dan@debian.org>
 *  Copyright (C) 1998 Dan Jacobowitz
 *  Copyright (C) 2001 Takashi Oe
 *
 *  Mmap code by Michel Lanners <mlan@cpu.lu>
 *
 *  Frame buffer structure from:
 *    drivers/video/chipsfb.c -- frame buffer device for
 *    Chips & Technologies 65550 chip.
 *
 *    Copyright (C) 1998 Paul Mackerras
 *
 *    This file is derived from the Powermac "chips" driver:
 *    Copyright (C) 1997 Fabio Riccardi.
 *    And from the frame buffer device for Open Firmware-initialized devices:
 *    Copyright (C) 1997 Geert Uytterhoeven.
 *
 *  Hardware information from:
 *    control.c: Console support for PowerMac "control" display adaptor.
 *    Copyright (C) 1996 Paul Mackerras
 *
 *  Updated to 2.5 framebuffer API by Ben Herrenschmidt
 *  <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>,
 *  and James Simmons <jsimmons@infradead.org>.
 *
 *  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.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/tty.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/nvram.h>
#include <linux/adb.h>
#include <linux/cuda.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/pgtable.h>
#include <asm/btext.h>

#include "macmodes.h"
#include "controlfb.h"

struct fb_par_control {
	int	vmode, cmode;
	int	xres, yres;
	int	vxres, vyres;
	int	xoffset, yoffset;
	int	pitch;
	struct control_regvals	regvals;
	unsigned long sync;
	unsigned char ctrl;
};

#define DIRTY(z) ((x)->z != (y)->z)
#define DIRTY_CMAP(z) (memcmp(&((x)->z), &((y)->z), sizeof((y)->z)))
static inline int PAR_EQUAL(struct fb_par_control *x, struct fb_par_control *y)
{
	int i, results;

	results = 1;
	for (i = 0; i < 3; i++)
		results &= !DIRTY(regvals.clock_params[i]);
	if (!results)
		return 0;
	for (i = 0; i < 16; i++)
		results &= !DIRTY(regvals.regs[i]);
	if (!results)
		return 0;
	return (!DIRTY(cmode) && !DIRTY(xres) && !DIRTY(yres)
		&& !DIRTY(vxres) && !DIRTY(vyres));
}
static inline int VAR_MATCH(struct fb_var_screeninfo *x, struct fb_var_screeninfo *y)
{
	return (!DIRTY(bits_per_pixel) && !DIRTY(xres)
		&& !DIRTY(yres) && !DIRTY(xres_virtual)
		&& !DIRTY(yres_virtual)
		&& !DIRTY_CMAP(red) && !DIRTY_CMAP(green) && !DIRTY_CMAP(blue));
}

struct fb_info_control {
	struct fb_info		info;
	struct fb_par_control	par;
	u32			pseudo_palette[17];
		
	struct cmap_regs	__iomem *cmap_regs;
	unsigned long		cmap_regs_phys;
	
	struct control_regs	__iomem *control_regs;
	unsigned long		control_regs_phys;
	unsigned long		control_regs_size;
	
	__u8			__iomem *frame_buffer;
	unsigned long		frame_buffer_phys;
	unsigned long		fb_orig_base;
	unsigned long		fb_orig_size;

	int			control_use_bank2;
	unsigned long		total_vram;
	unsigned char		vram_attr;
};

/* control register access macro */
#define CNTRL_REG(INFO,REG) (&(((INFO)->control_regs->REG).r))


/******************** Prototypes for exported functions ********************/
/*
 * struct fb_ops
 */
static int controlfb_pan_display(struct fb_var_screeninfo *var,
	struct fb_info *info);
static int controlfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
	u_int transp, struct fb_info *info);
static int controlfb_blank(int blank_mode, struct fb_info *info);
static int controlfb_mmap(struct fb_info *info, struct file *file,
	struct vm_area_struct *vma);
static int controlfb_set_par (struct fb_info *info);
static int controlfb_check_var (struct fb_var_screeninfo *var, struct fb_info *info);

/*
 * inititialization
 */
int control_init(void);
void control_setup(char *);

/******************** Prototypes for internal functions **********************/

static void set_control_clock(unsigned char *params);
static int init_control(struct fb_info_control *p);
static void control_set_hardware(struct fb_info_control *p,
	struct fb_par_control *par);
static int control_of_init(struct device_node *dp);
static void find_vram_size(struct fb_info_control *p);
static int read_control_sense(struct fb_info_control *p);
static int calc_clock_params(unsigned long clk, unsigned char *param);
static int control_var_to_par(struct fb_var_screeninfo *var,
	struct fb_par_control *par, const struct fb_info *fb_info);
static inline void control_par_to_var(struct fb_par_control *par,
	struct fb_var_screeninfo *var);
static void control_init_info(struct fb_info *info, struct fb_info_control *p);
static void control_cleanup(void);


/************************** Internal variables *******************************/

static struct fb_info_control *control_fb;

static int default_vmode __initdata = VMODE_NVRAM;
static int default_cmode __initdata = CMODE_NVRAM;


static struct fb_ops controlfb_ops = {
	.owner		= THIS_MODULE,
	.fb_check_var	= controlfb_check_var,
	.fb_set_par	= controlfb_set_par,
	.fb_setcolreg	= controlfb_setcolreg,
	.fb_pan_display = controlfb_pan_display,
	.fb_blank	= controlfb_blank,
	.fb_mmap	= controlfb_mmap,
	.fb_fillrect	= cfb_fillrect,
	.fb_copyarea	= cfb_copyarea,
	.fb_imageblit	= cfb_imageblit,
};


/********************  The functions for controlfb_ops ********************/

#ifdef MODULE
MODULE_LICENSE("GPL");

int init_module(void)
{
	struct device_node *dp;

	dp = find_devices("control");
	if (dp != 0 && !control_of_init(dp))
		return 0;

	return -ENXIO;
}

void cleanup_module(void)
{
	control_cleanup();
}
#endif

/*
 * Checks a var structure
 */
static int controlfb_check_var (struct fb_var_screeninfo *var, struct fb_info *info)
{
	struct fb_par_control par;
	int err;

	err = control_var_to_par(var, &par, info);
	if (err)
		return err;	
	control_par_to_var(&par, var);

	return 0;
}

/*
 * Applies current var to display
 */
static int controlfb_set_par (struct fb_info *info)
{
	struct fb_info_control *p = (struct fb_info_control *) info;
	struct fb_par_control par;
	int err;

	if((err = control_var_to_par(&info->var, &par, info))) {
		printk (KERN_ERR "controlfb_set_par: error calling"
				 " control_var_to_par: %d.\n", err);
		return err;
	}
	
	control_set_hardware(p, &par);

	info->fix.visual = (p->par.cmode == CMODE_8) ?
		FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_DIRECTCOLOR;
	info->fix.line_length = p->par.pitch;
	info->fix.xpanstep = 32 >> p->par.cmode;
	info->fix.ypanstep = 1;

	return 0;
}

/*
 * Set screen start address according to var offset values
 */
static inline void set_screen_start(int xoffset, int yoffset,
	struct fb_info_control *p)
{
	struct fb_par_control *par = &p->par;

	par->xoffset = xoffset;
	par->yoffset = yoffset;
	out_le32(CNTRL_REG(p,start_addr),
		 par->yoffset * par->pitch + (par->xoffset << par->cmode));
}


static int controlfb_pan_display(struct fb_var_screeninfo *var,
				 struct fb_info *info)
{
	unsigned int xoffset, hstep;
	struct fb_info_control *p = (struct fb_info_control *)info;
	struct fb_par_control *par = &p->par;

	/*
	 * make sure start addr will be 32-byte aligned
	 */
	hstep = 0x1f >> par->cmode;
	xoffset = (var->xoffset + hstep) & ~hstep;

	if (xoffset+par->xres > par->vxres ||
	    var->yoffset+par->yres > par->vyres)
		return -EINVAL;

	set_screen_start(xoffset, var->yoffset, p);

	return 0;
}


/*
 * Private mmap since we want to have a different caching on the framebuffer
 * for controlfb.
 * Note there's no locking in here; it's done in fb_mmap() in fbmem.c.
 */
static int controlfb_mmap(struct fb_info *info, struct file *file,
                       struct vm_area_struct *vma)
{
       unsigned long off, start;
       u32 len;

       off = vma->vm_pgoff << PAGE_SHIFT;

       /* frame buffer memory */
       start = info->fix.smem_start;
       len = PAGE_ALIGN((start & ~PAGE_MASK)+info->fix.smem_len);
       if (off >= len) {
               /* memory mapped io */
               off -= len;
               if (info->var.accel_flags)
                       return -EINVAL;
               start = info->fix.mmio_start;
               len = PAGE_ALIGN((start & ~PAGE_MASK)+info->fix.mmio_len);
               pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE|_PAGE_GUARDED;
       } else {
               /* framebuffer */
               pgprot_val(vma->vm_page_prot) |= _PAGE_WRITETHRU;
       }
       start &= PAGE_MASK;
       if ((vma->vm_end - vma->vm_start + off) > len)
       		return -EINVAL;
       off += start;
       vma->vm_pgoff = off >> PAGE_SHIFT;
       if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
           vma->vm_end - vma->vm_start, vma->vm_page_prot))
               return -EAGAIN;

       return 0;
}

static int controlfb_blank(int blank_mode, struct fb_info *info)
{
	struct fb_info_control *p = (struct fb_info_control *) info;
	unsigned ctrl;

	ctrl = ld_le32(CNTRL_REG(p,ctrl));
	if (blank_mode > 0)
		switch (blank_mode) {
		case FB_BLANK_VSYNC_SUSPEND:
			ctrl &= ~3;
			break;
		case FB_BLANK_HSYNC_SUSPEND:
			ctrl &= ~0x30;
			break;
		case FB_BLANK_POWERDOWN:
			ctrl &= ~0x33;
			/* fall through */
		case FB_BLANK_NORMAL:
			ctrl |= 0x400;
			break;
		default:
			break;
		}
	else {
		ctrl &= ~0x400;
		ctrl |= 0x33;
	}
	out_le32(CNTRL_REG(p,ctrl), ctrl);

	return 0;
}

static int controlfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
			     u_int transp, struct fb_info *info)
{
	struct fb_info_control *p = (struct fb_info_control *) info;
	__u8 r, g, b;

	if (regno > 255)
		return 1;

	r = red >> 8;
	g = green >> 8;
	b = blue >> 8;

	out_8(&p->cmap_regs->addr, regno);	/* tell clut what addr to fill	*/
	out_8(&p->cmap_regs->lut, r);		/* send one color channel at	*/
	out_8(&p->cmap_regs->lut, g);		/* a time...			*/
	out_8(&p->cmap_regs->lut, b);

	if (regno < 16) {
		int i;
		switch (p->par.cmode) {
		case CMODE_16:
			p->pseudo_palette[regno] =
			    (regno << 10) | (regno << 5) | regno;
			break;
		case CMODE_32:
			i = (regno << 8) | regno;
			p->pseudo_palette[regno] = (i << 16) | i;
			break;
		}
	}

	return 0;
}


/********************  End of controlfb_ops implementation  ******************/



static void set_control_clock(unsigned char *params)
{
#ifdef CONFIG_ADB_CUDA
	struct adb_request req;
	int i;

	for (i = 0; i < 3; ++i) {
		cuda_request(&req, NULL, 5, CUDA_PACKET, CUDA_GET_SET_IIC,
			     0x50, i + 1, params[i]);
		while (!req.complete)
			cuda_poll();
	}
#endif	
}


/*
 * finish off the driver initialization and register
 */
static int __init init_control(struct fb_info_control *p)
{
	int full, sense, vmode, cmode, vyres;
	struct fb_var_screeninfo var;
	int rc;
	
	printk(KERN_INFO "controlfb: ");

	full = p->total_vram == 0x400000;

	/* Try to pick a video mode out of NVRAM if we have one. */
	if (default_cmode == CMODE_NVRAM){
		cmode = nvram_read_byte(NV_CMODE);
		if(cmode < CMODE_8 || cmode > CMODE_32)
			cmode = CMODE_8;
	} else
		cmode=default_cmode;

	if (default_vmode == VMODE_NVRAM) {
		vmode = nvram_read_byte(NV_VMODE);
		if (vmode < 1 || vmode > VMODE_MAX ||
		    control_mac_modes[vmode - 1].m[full] < cmode) {
			sense = read_control_sense(p);
			printk("Monitor sense value = 0x%x, ", sense);
			vmode = mac_map_monitor_sense(sense);
			if (control_mac_modes[vmode - 1].m[full] < cmode)
				vmode = VMODE_640_480_60;
		}
	} else {
		vmode=default_vmode;
		if (control_mac_modes[vmode - 1].m[full] < cmode) {
			if (cmode > CMODE_8)
				cmode--;
			else
				vmode = VMODE_640_480_60;
		}
	}

	/* Initialize info structure */
	control_init_info(&p->info, p);

	/* Setup default var */
	if (mac_vmode_to_var(vmode, cmode, &var) < 0) {
		/* This shouldn't happen! */
		printk("mac_vmode_to_var(%d, %d,) failed\n", vmode, cmode);
try_again:
		vmode = VMODE_640_480_60;
		cmode = CMODE_8;
		if (mac_vmode_to_var(vmode, cmode, &var) < 0) {
			printk(KERN_ERR "controlfb: mac_vmode_to_var() failed\n");
			return -ENXIO;
		}
		printk(KERN_INFO "controlfb: ");
	}
	printk("using video mode %d and color mode %d.\n", vmode, cmode);

	vyres = (p->total_vram - CTRLFB_OFF) / (var.xres << cmode);
	if (vyres > var.yres)
		var.yres_virtual = vyres;

	/* Apply default var */
	var.activate = FB_ACTIVATE_NOW;
	rc = fb_set_var(&p->info, &var);
	if (rc && (vmode != VMODE_640_480_60 || cmode != CMODE_8))
		goto try_again;

	/* Register with fbdev layer */
	if (register_framebuffer(&p->info) < 0)
		return -ENXIO;
	
	printk(KERN_INFO "fb%d: control display adapter\n", p->info.node);	

	return 0;
}

#define RADACAL_WRITE(a,d) \
	out_8(&p->cmap_regs->addr, (a)); \
	out_8(&p->cmap_regs->dat,   (d))

/* Now how about actually saying, Make it so! */
/* Some things in here probably don't need to be done each time. */
static void control_set_hardware(struct fb_info_control *p, struct fb_par_control *par)
{
	struct control_regvals	*r;
	volatile struct preg	__iomem *rp;
	int			i, cmode;

	if (PAR_EQUAL(&p->par, par)) {
		/*
		 * check if only xoffset or yoffset differs.
		 * this prevents flickers in typical VT switch case.
		 */
		if (p->par.xoffset != par->xoffset ||
		    p->par.yoffset != par->yoffset)
			set_screen_start(par->xoffset, par->yoffset, p);
			
		return;
	}
	
	p->par = *par;
	cmode = p->par.cmode;
	r = &par->regvals;
	
	/* Turn off display */
	out_le32(CNTRL_REG(p,ctrl), 0x400 | par->ctrl);
	
	set_control_clock(r->clock_params);
	
	RADACAL_WRITE(0x20, r->radacal_ctrl);
	RADACAL_WRITE(0x21, p->control_use_bank2 ? 0 : 1);
	RADACAL_WRITE(0x10, 0);
	RADACAL_WRITE(0x11, 0);

	rp = &p->control_regs->vswin;
	for (i = 0; i < 16; ++i, ++rp)
		out_le32(&rp->r, r->regs[i]);
	
	out_le32(CNTRL_REG(p,pitch), par->pitch);
	out_le32(CNTRL_REG(p,mode), r->mode);
	out_le32(CNTRL_REG(p,vram_attr), p->vram_attr);
	out_le32(CNTRL_REG(p,start_addr), par->yoffset * par->pitch
		 + (par->xoffset << cmode));
	out_le32(CNTRL_REG(p,rfrcnt), 0x1e5);
	out_le32(CNTRL_REG(p,intr_ena), 0);

	/* Turn on display */
	out_le32(CNTRL_REG(p,ctrl), par->ctrl);

#ifdef CONFIG_BOOTX_TEXT
	btext_update_display(p->frame_buffer_phys + CTRLFB_OFF,
			     p->par.xres, p->par.yres,
			     (cmode == CMODE_32? 32: cmode == CMODE_16? 16: 8),
			     p->par.pitch);
#endif /* CONFIG_BOOTX_TEXT */
}


/*
 * Called from fbmem.c for probing & initializing
 */
int __init control_init(void)
{
	struct device_node *dp;
	char *option = NULL;

	if (fb_get_options("controlfb", &option))
		return -ENODEV;
	control_setup(option);

	dp = find_devices("control");
	if (dp != 0 && !control_of_init(dp))
		return 0;

	return -ENXIO;
}

module_init(control_init);

/* Work out which banks of VRAM we have installed. */
/* danj: I guess the card just ignores writes to nonexistant VRAM... */

static void __init find_vram_size(struct fb_info_control *p)
{
	int bank1, bank2;

	/*
	 * Set VRAM in 2MB (bank 1) mode
	 * VRAM Bank 2 will be accessible through offset 0x600000 if present
	 * and VRAM Bank 1 will not respond at that offset even if present
	 */
	out_le32(CNTRL_REG(p,vram_attr), 0x31);

	out_8(&p->frame_buffer[0x600000], 0xb3);
	out_8(&p->frame_buffer[0x600001], 0x71);
	asm volatile("eieio; dcbf 0,%0" : : "r" (&p->frame_buffer[0x600000])
					: "memory" );
	mb();
	asm volatile("eieio; dcbi 0,%0" : : "r" (&p->frame_buffer[0x600000])
					: "memory" );
	mb();

	bank2 = (in_8(&p->frame_buffer[0x600000]) == 0xb3)
		&& (in_8(&p->frame_buffer[0x600001]) == 0x71);

	/*
	 * Set VRAM in 2MB (bank 2) mode
	 * VRAM Bank 1 will be accessible through offset 0x000000 if present
	 * and VRAM Bank 2 will not respond at that offset even if present
	 */
	out_le32(CNTRL_REG(p,vram_attr), 0x39);

	out_8(&p->frame_buffer[0], 0x5a);
	out_8(&p->frame_buffer[1], 0xc7);
	asm volatile("eieio; dcbf 0,%0" : : "r" (&p->frame_buffer[0])
					: "memory" );
	mb();
	asm volatile("eieio; dcbi 0,%0" : : "r" (&p->frame_buffer[0])
					: "memory" );
	mb();

	bank1 = (in_8(&p->frame_buffer[0]) == 0x5a)
		&& (in_8(&p->frame_buffer[1]) == 0xc7);

	if (bank2) {
		if (!bank1) {
			/*
			 * vram bank 2 only
			 */
			p->control_use_bank2 = 1;
			p->vram_attr = 0x39;
			p->frame_buffer += 0x600000;
			p->frame_buffer_phys += 0x600000;
		} else {
			/*
			 * 4 MB vram
			 */
			p->vram_attr = 0x51;
		}
	} else {
		/*
		 * vram bank 1 only
		 */
		p->vram_attr = 0x31;
	}

        p->total_vram = (bank1 + bank2) * 0x200000;

	printk(KERN_INFO "controlfb: VRAM Total = %dMB "
			"(%dMB @ bank 1, %dMB @ bank 2)\n",
			(bank1 + bank2) << 1, bank1 << 1, bank2 << 1);
}


/*
 * find "control" and initialize
 */
static int __init control_of_init(struct device_node *dp)
{
	struct fb_info_control	*p;
	unsigned long		addr;
	int			i;

	if (control_fb) {
		printk(KERN_ERR "controlfb: only one control is supported\n");
		return -ENXIO;
	}
	if(dp->n_addrs != 2) {
		printk(KERN_ERR "expecting 2 address for control (got %d)", dp->n_addrs);
		return -ENXIO;
	}
	p = kmalloc(sizeof(*p), GFP_KERNEL);
	if (p == 0)
		return -ENXIO;
	control_fb = p;	/* save it for cleanups */
	memset(p, 0, sizeof(*p));

	/* Map in frame buffer and registers */
	for (i = 0; i < dp->n_addrs; ++i) {
		addr = dp->addrs[i].address;
		if (dp->addrs[i].size >= 0x800000) {
			p->fb_orig_base = addr;
			p->fb_orig_size = dp->addrs[i].size;
			/* use the big-endian aperture (??) */
			p->frame_buffer_phys = addr + 0x800000;
		} else {
			p->control_regs_phys = addr;
			p->control_regs_size = dp->addrs[i].size;
		}
	}

	if (!p->fb_orig_base ||
	    !request_mem_region(p->fb_orig_base,p->fb_orig_size,"controlfb")) {
		p->fb_orig_base = 0;
		goto error_out;
	}
	/* map at most 8MB for the frame buffer */
	p->frame_buffer = __ioremap(p->frame_buffer_phys, 0x800000,
				    _PAGE_WRITETHRU);

	if (!p->control_regs_phys ||
	    !request_mem_region(p->control_regs_phys, p->control_regs_size,
	    "controlfb regs")) {
		p->control_regs_phys = 0;
		goto error_out;
	}
	p->control_regs = ioremap(p->control_regs_phys, p->control_regs_size);

	p->cmap_regs_phys = 0xf301b000;	 /* XXX not in prom? */
	if (!request_mem_region(p->cmap_regs_phys, 0x1000, "controlfb cmap")) {
		p->cmap_regs_phys = 0;
		goto error_out;
	}
	p->cmap_regs = ioremap(p->cmap_regs_phys, 0x1000);

	if (!p->cmap_regs || !p->control_regs || !p->frame_buffer)
		goto error_out;

	find_vram_size(p);
	if (!p->total_vram)
		goto error_out;

	if (init_control(p) < 0)
		goto error_out;

	return 0;

error_out:
	control_cleanup();
	return -ENXIO;
}

/*
 * Get the monitor sense value.
 * Note that this can be called before calibrate_delay,
 * so we can't use udelay.
 */
static int read_control_sense(struct fb_info_control *p)
{
	int sense;

	out_le32(CNTRL_REG(p,mon_sense), 7);	/* drive all lines high */
	__delay(200);
	out_le32(CNTRL_REG(p,mon_sense), 077);	/* turn off drivers */
	__delay(2000);
	sense = (in_le32(CNTRL_REG(p,mon_sense)) & 0x1c0) << 2;

	/* drive each sense line low in turn and collect the other 2 */
	out_le32(CNTRL_REG(p,mon_sense), 033);	/* drive A low */
	__delay(2000);
	sense |= (in_le32(CNTRL_REG(p,mon_sense)) & 0xc0) >> 2;
	out_le32(CNTRL_REG(p,mon_sense), 055);	/* drive B low */
	__delay(2000);
	sense |= ((in_le32(CNTRL_REG(p,mon_sense)) & 0x100) >> 5)
		| ((in_le32(CNTRL_REG(p,mon_sense)) & 0x40) >> 4);
	out_le32(CNTRL_REG(p,mon_sense), 066);	/* drive C low */
	__delay(2000);
	sense |= (in_le32(CNTRL_REG(p,mon_sense)) & 0x180) >> 7;

	out_le32(CNTRL_REG(p,mon_sense), 077);	/* turn off drivers */
	
	return sense;
}

/**********************  Various translation functions  **********************/

#define CONTROL_PIXCLOCK_BASE	256016
#define CONTROL_PIXCLOCK_MIN	5000	/* ~ 200 MHz dot clock */

/*
 * calculate the clock paramaters to be sent to CUDA according to given
 * pixclock in pico second.
 */
static int calc_clock_params(unsigned long clk, unsigned char *param)
{
	unsigned long p0, p1, p2, k, l, m, n, min;

	if (clk > (CONTROL_PIXCLOCK_BASE << 3))
		return 1;

	p2 = ((clk << 4) < CONTROL_PIXCLOCK_BASE)? 3: 2;
	l = clk << p2;
	p0 = 0;
	p1 = 0;
	for (k = 1, min = l; k < 32; k++) {
		unsigned long rem;

		m = CONTROL_PIXCLOCK_BASE * k;
		n = m / l;
		rem = m % l;
		if (n && (n < 128) && rem < min) {
			p0 = k;
			p1 = n;
			min = rem;
		}
	}
	if (!p0 || !p1)
		return 1;

	param[0] = p0;
	param[1] = p1;
	param[2] = p2;

	return 0;
}


/*
 * This routine takes a user-supplied var, and picks the best vmode/cmode
 * from it.
 */

static int control_var_to_par(struct fb_var_screeninfo *var,
	struct fb_par_control *par, const struct fb_info *fb_info)
{
	int cmode, piped_diff, hstep;
	unsigned hperiod, hssync, hsblank, hesync, heblank, piped, heq, hlfln,
		 hserr, vperiod, vssync, vesync, veblank, vsblank, vswin, vewin;
	unsigned long pixclock;
	struct fb_info_control *p = (struct fb_info_control *) fb_info;
	struct control_regvals *r = &par->regvals;

	switch (var->bits_per_pixel) {
	case 8:
		par->cmode = CMODE_8;
		if (p->total_vram > 0x200000) {
			r->mode = 3;
			r->radacal_ctrl = 0x20;
			piped_diff = 13;
		} else {
			r->mode = 2;
			r->radacal_ctrl = 0x10;
			piped_diff = 9;
		}
		break;
	case 15:
	case 16:
		par->cmode = CMODE_16;
		if (p->total_vram > 0x200000) {
			r->mode = 2;
			r->radacal_ctrl = 0x24;
			piped_diff = 5;
		} else {
			r->mode = 1;
			r->radacal_ctrl = 0x14;
			piped_diff = 3;
		}
		break;
	case 32:
		par->cmode = CMODE_32;
		if (p->total_vram > 0x200000) {
			r->mode = 1;
			r->radacal_ctrl = 0x28;
		} else {
			r->mode = 0;
			r->radacal_ctrl = 0x18;
		}
		piped_diff = 1;
		break;
	default:
		return -EINVAL;
	}

	/*
	 * adjust xres and vxres so that the corresponding memory widths are
	 * 32-byte aligned
	 */
	hstep = 31 >> par->cmode;
	par->xres = (var->xres + hstep) & ~hstep;
	par->vxres = (var->xres_virtual + hstep) & ~hstep;
	par->xoffset = (var->xoffset + hstep) & ~hstep;
	if (par->vxres < par->xres)
		par->vxres = par->xres;
	par->pitch = par->vxres << par->cmode;

	par->yres = var->yres;
	par->vyres = var->yres_virtual;
	par->yoffset = var->yoffset;
	if (par->vyres < par->yres)
		par->vyres = par->yres;

	par->sync = var->sync;

	if (par->pitch * par->vyres + CTRLFB_OFF > p->total_vram)
		return -EINVAL;

	if (par->xoffset + par->xres > par->vxres)
		par->xoffset = par->vxres - par->xres;
	if (par->yoffset + par->yres > par->vyres)
		par->yoffset = par->vyres - par->yres;

	pixclock = (var->pixclock < CONTROL_PIXCLOCK_MIN)? CONTROL_PIXCLOCK_MIN:
		   var->pixclock;
	if (calc_clock_params(pixclock, r->clock_params))
		return -EINVAL;

	hperiod = ((var->left_margin + par->xres + var->right_margin
		    + var->hsync_len) >> 1) - 2;
	hssync = hperiod + 1;
	hsblank = hssync - (var->right_margin >> 1);
	hesync = (var->hsync_len >> 1) - 1;
	heblank = (var->left_margin >> 1) + hesync;
	piped = heblank - piped_diff;
	heq = var->hsync_len >> 2;
	hlfln = (hperiod+2) >> 1;
	hserr = hssync-hesync;
	vperiod = (var->vsync_len + var->lower_margin + par->yres
		   + var->upper_margin) << 1;
	vssync = vperiod - 2;
	vesync = (var->vsync_len << 1) - vperiod + vssync;
	veblank = (var->upper_margin << 1) + vesync;
	vsblank = vssync - (var->lower_margin << 1);
	vswin = (vsblank+vssync) >> 1;
	vewin = (vesync+veblank) >> 1;

	r->regs[0] = vswin;
	r->regs[1] = vsblank;
	r->regs[2] = veblank;
	r->regs[3] = vewin;
	r->regs[4] = vesync;
	r->regs[5] = vssync;
	r->regs[6] = vperiod;
	r->regs[7] = piped;
	r->regs[8] = hperiod;
	r->regs[9] = hsblank;
	r->regs[10] = heblank;
	r->regs[11] = hesync;
	r->regs[12] = hssync;
	r->regs[13] = heq;
	r->regs[14] = hlfln;
	r->regs[15] = hserr;

	if (par->xres >= 1280 && par->cmode >= CMODE_16)
		par->ctrl = 0x7f;
	else
		par->ctrl = 0x3b;

	if (mac_var_to_vmode(var, &par->vmode, &cmode))
		par->vmode = 0;

	return 0;
}


/*
 * Convert hardware data in par to an fb_var_screeninfo
 */

static void control_par_to_var(struct fb_par_control *par, struct fb_var_screeninfo *var)
{
	struct control_regints *rv;
	
	rv = (struct control_regints *) par->regvals.regs;
	
	memset(var, 0, sizeof(*var));
	var->xres = par->xres;
	var->yres = par->yres;
	var->xres_virtual = par->vxres;
	var->yres_virtual = par->vyres;
	var->xoffset = par->xoffset;
	var->yoffset = par->yoffset;
	
	switch(par->cmode) {
	default:
	case CMODE_8:
		var->bits_per_pixel = 8;
		var->red.length = 8;
		var->green.length = 8;
		var->blue.length = 8;
		break;
	case CMODE_16:	/* RGB 555 */
		var->bits_per_pixel = 16;
		var->red.offset = 10;
		var->red.length = 5;
		var->green.offset = 5;
		var->green.length = 5;
		var->blue.length = 5;
		break;
	case CMODE_32:	/* RGB 888 */
		var->bits_per_pixel = 32;
		var->red.offset = 16;
		var->red.length = 8;
		var->green.offset = 8;
		var->green.length = 8;
		var->blue.length = 8;
		var->transp.offset = 24;
		var->transp.length = 8;
		break;
	}
	var->height = -1;
	var->width = -1;
	var->vmode = FB_VMODE_NONINTERLACED;

	var->left_margin = (rv->heblank - rv->hesync) << 1;
	var->right_margin = (rv->hssync - rv->hsblank) << 1;
	var->hsync_len = (rv->hperiod + 2 - rv->hssync + rv->hesync) << 1;

	var->upper_margin = (rv->veblank - rv->vesync) >> 1;
	var->lower_margin = (rv->vssync - rv->vsblank) >> 1;
	var->vsync_len = (rv->vperiod - rv->vssync + rv->vesync) >> 1;

	var->sync = par->sync;

	/*
	 * 10^12 * clock_params[0] / (3906400 * clock_params[1]
	 *			      * 2^clock_params[2])
	 * (10^12 * clock_params[0] / (3906400 * clock_params[1]))
	 * >> clock_params[2]
	 */
	/* (255990.17 * clock_params[0] / clock_params[1]) >> clock_params[2] */
	var->pixclock = CONTROL_PIXCLOCK_BASE * par->regvals.clock_params[0];
	var->pixclock /= par->regvals.clock_params[1];
	var->pixclock >>= par->regvals.clock_params[2];
}

/*
 * Set misc info vars for this driver
 */
static void __init control_init_info(struct fb_info *info, struct fb_info_control *p)
{
	/* Fill fb_info */
	info->par = &p->par;
	info->fbops = &controlfb_ops;
	info->pseudo_palette = p->pseudo_palette;
        info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
	info->screen_base = p->frame_buffer + CTRLFB_OFF;

	fb_alloc_cmap(&info->cmap, 256, 0);

	/* Fill fix common fields */
	strcpy(info->fix.id, "control");
	info->fix.mmio_start = p->control_regs_phys;
	info->fix.mmio_len = sizeof(struct control_regs);
	info->fix.type = FB_TYPE_PACKED_PIXELS;
	info->fix.smem_start = p->frame_buffer_phys + CTRLFB_OFF;
	info->fix.smem_len = p->total_vram - CTRLFB_OFF;
        info->fix.ywrapstep = 0;
        info->fix.type_aux = 0;
        info->fix.accel = FB_ACCEL_NONE;
}


static void control_cleanup(void)
{
	struct fb_info_control	*p = control_fb;

	if (!p)
		return;

	if (p->cmap_regs)
		iounmap(p->cmap_regs);
	if (p->control_regs)
		iounmap(p->control_regs);
	if (p->frame_buffer) {
		if (p->control_use_bank2)
			p->frame_buffer -= 0x600000;
		iounmap(p->frame_buffer);
	}
	if (p->cmap_regs_phys)
		release_mem_region(p->cmap_regs_phys, 0x1000);
	if (p->control_regs_phys)
		release_mem_region(p->control_regs_phys, p->control_regs_size);
	if (p->fb_orig_base)
		release_mem_region(p->fb_orig_base, p->fb_orig_size);
	kfree(p);
}


/*
 * Parse user speficied options (`video=controlfb:')
 */
void __init control_setup(char *options)
{
	char *this_opt;

	if (!options || !*options)
		return;

	while ((this_opt = strsep(&options, ",")) != NULL) {
		if (!strncmp(this_opt, "vmode:", 6)) {
			int vmode = simple_strtoul(this_opt+6, NULL, 0);
			if (vmode > 0 && vmode <= VMODE_MAX &&
			    control_mac_modes[vmode - 1].m[1] >= 0)
				default_vmode = vmode;
		} else if (!strncmp(this_opt, "cmode:", 6)) {
			int depth = simple_strtoul(this_opt+6, NULL, 0);
			switch (depth) {
			 case CMODE_8:
			 case CMODE_16:
			 case CMODE_32:
			 	default_cmode = depth;
			 	break;
			 case 8:
				default_cmode = CMODE_8;
				break;
			 case 15:
			 case 16:
				default_cmode = CMODE_16;
				break;
			 case 24:
			 case 32:
				default_cmode = CMODE_32;
				break;
			}
		}
	}
}