summaryrefslogtreecommitdiff
path: root/firmware/drivers/lcd-ipod.c
blob: e65d5006545f4fc37ad9790d222138223ad64e29 (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
/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Rockbox driver for iPod LCDs
 *
 * Based on code from the ipodlinux project - http://ipodlinux.org/
 * Adapted for Rockbox in November 2005
 *
 * Original file: linux/arch/armnommu/mach-ipod/fb.c
 *
 * Copyright (c) 2003-2005 Bernard Leach (leachbj@bouncycastle.org)
 *
 * All files in this archive are subject to the GNU General Public License.
 * See the file COPYING in the source tree root for full license agreement.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
#include "config.h"
#include "cpu.h"
#include "lcd.h"
#include "kernel.h"
#include "system.h"


/* check if number of useconds has past */
static inline bool timer_check(int clock_start, int usecs)
{
    return ((int)(USEC_TIMER - clock_start)) >= usecs;
}

#if (CONFIG_LCD == LCD_IPOD2BPP) || (CONFIG_LCD == LCD_IPODMINI)

/*** hardware configuration ***/

#if CONFIG_CPU == PP5002
#define IPOD_LCD_BASE            0xc0001000
#define IPOD_LCD_BUSY_MASK       0x80000000
#else /* PP5020 */
#define IPOD_LCD_BASE            0x70003000
#define IPOD_LCD_BUSY_MASK       0x00008000
#endif

/* LCD command codes for HD66753 */

#define LCD_CMD  0x08
#define LCD_DATA 0x10

#define R_START_OSC             0x00
#define R_DRV_OUTPUT_CONTROL    0x01
#define R_DRV_WAVEFORM_CONTROL  0x02
#define R_POWER_CONTROL         0x03
#define R_CONTRAST_CONTROL      0x04
#define R_ENTRY_MODE            0x05
#define R_ROTATION              0x06
#define R_DISPLAY_CONTROL       0x07
#define R_CURSOR_CONTROL        0x08
#define R_HORIZONTAL_CURSOR_POS 0x0b
#define R_VERTICAL_CURSOR_POS   0x0c
#define R_1ST_SCR_DRV_POS       0x0d
#define R_2ND_SCR_DRV_POS       0x0e
#define R_RAM_WRITE_MASK        0x10
#define R_RAM_ADDR_SET          0x11
#define R_RAM_DATA              0x12

/* needed for flip */
static int addr_offset;
#if defined(IPOD_MINI) || defined(IPOD_MINI2G)
static int pix_offset;
#endif

static const unsigned char dibits[16] ICONST_ATTR = {
    0x00, 0x03, 0x0C, 0x0F, 0x30, 0x33, 0x3C, 0x3F,
    0xC0, 0xC3, 0xCC, 0xCF, 0xF0, 0xF3, 0xFC, 0xFF
};

/* wait for LCD with timeout */
static inline void lcd_wait_write(void)
{
    int start = USEC_TIMER;

    do {
        if ((inl(IPOD_LCD_BASE) & 0x8000) == 0) break;
    } while (timer_check(start, 1000) == 0);
}


/* send LCD data */
static void lcd_send_data(unsigned data)
{
    lcd_wait_write();
#ifdef IPOD_MINI2G
    outl((inl(IPOD_LCD_BASE) & ~0x1f00000) | 0x1700000, IPOD_LCD_BASE);
    outl(data | 0x760000, IPOD_LCD_BASE+8);
#else
    outl(data >> 8, IPOD_LCD_BASE + LCD_DATA);
    lcd_wait_write();
    outl(data & 0xff, IPOD_LCD_BASE + LCD_DATA);
#endif
}

/* send LCD command */
static void lcd_prepare_cmd(unsigned cmd)
{
    lcd_wait_write();
#ifdef IPOD_MINI2G
    outl((inl(IPOD_LCD_BASE) & ~0x1f00000) | 0x1700000, IPOD_LCD_BASE);
    outl(cmd | 0x740000, IPOD_LCD_BASE+8);
#else
    outl(0x0, IPOD_LCD_BASE + LCD_CMD);
    lcd_wait_write();
    outl(cmd, IPOD_LCD_BASE + LCD_CMD);
#endif
}

/* send LCD command and data */
static void lcd_cmd_and_data(unsigned cmd, unsigned data)
{
    lcd_prepare_cmd(cmd);
    lcd_send_data(data);
}

/* LCD init */
void lcd_init_device(void)
{
    lcd_cmd_and_data(R_DISPLAY_CONTROL, 0x0009);
    lcd_set_flip(false);
    lcd_cmd_and_data(R_ENTRY_MODE, 0x0000);

#ifdef IPOD_4G
    outl(inl(0x6000d004) | 0x4, 0x6000d004); /* B02 enable */
    outl(inl(0x6000d004) | 0x8, 0x6000d004); /* B03 enable */
    outl(inl(0x70000084) | 0x2000000, 0x70000084); /* D01 enable */
    outl(inl(0x70000080) | 0x2000000, 0x70000080); /* D01 =1 */

    outl(inl(0x6000600c) | 0x20000, 0x6000600c);    /* PWM enable */
#endif
}

/*** hardware configuration ***/

int lcd_default_contrast(void)
{
#if defined(IPOD_MINI) || defined(IPOD_MINI2G) || defined(IPOD_3G)
    return 42;
#else
    return 35;
#endif
}

/* Rockbox stores the contrast as 0..63 - we add 64 to it */
void lcd_set_contrast(int val)
{
    if (val < 0) val = 0;
    else if (val > 63) val = 63;

    lcd_cmd_and_data(R_CONTRAST_CONTROL, 0x400 | (val + 64));
}

void lcd_set_invert_display(bool yesno)
{
    if (yesno)
        lcd_cmd_and_data(R_DISPLAY_CONTROL, 0x0023);
    else
        lcd_cmd_and_data(R_DISPLAY_CONTROL, 0x0009);
}

/* turn the display upside down (call lcd_update() afterwards) */
void lcd_set_flip(bool yesno)
{
#if defined(IPOD_MINI) || defined(IPOD_MINI2G)
    if (yesno) {
         /* 168x112, inverse COM order */
        lcd_cmd_and_data(R_DRV_OUTPUT_CONTROL, 0x020d);
        lcd_cmd_and_data(R_1ST_SCR_DRV_POS, 0x8316);    /* 22..131 */
        addr_offset = (22 << 5) | (20 - 4);
        pix_offset = -2;
    } else {
        /* 168x112,  inverse SEG order */
        lcd_cmd_and_data(R_DRV_OUTPUT_CONTROL, 0x010d);
        lcd_cmd_and_data(R_1ST_SCR_DRV_POS, 0x6d00);    /* 0..109 */
        addr_offset = 20;
        pix_offset = 0;
    }
#else
    if (yesno) {
        /* 168x128, inverse SEG & COM order */
        lcd_cmd_and_data(R_DRV_OUTPUT_CONTROL, 0x030f);
        lcd_cmd_and_data(R_1ST_SCR_DRV_POS, 0x8304);    /* 4..131 */
        addr_offset = (4 << 5) | (20 - 1);
    } else {
        /* 168x128 */
        lcd_cmd_and_data(R_DRV_OUTPUT_CONTROL, 0x000f);
        lcd_cmd_and_data(R_1ST_SCR_DRV_POS, 0x7f00);    /* 0..127 */
        addr_offset = 20;
    }
#endif
}

/*** update functions ***/

/* Performance function that works with an external buffer
   note that x, bwidtht and stride are in 8-pixel units! */
void lcd_blit(const unsigned char* data, int bx, int y, int bwidth,
              int height, int stride)
{
    const unsigned char *src, *src_end;

    while (height--) {
        src = data;
        src_end = data + bwidth;
        lcd_cmd_and_data(R_RAM_ADDR_SET, (y++ << 5) + addr_offset - bx);
        lcd_prepare_cmd(R_RAM_DATA);
        do {
            unsigned byte = *src++;
            lcd_send_data((dibits[byte>>4] << 8) | dibits[byte&0x0f]);
        } while (src < src_end);
        data += stride;
    }
}

void lcd_update_rect(int x, int y, int width, int height)
{
    int xmax, ymax;

    if (x + width > LCD_WIDTH)
        width = LCD_WIDTH - x;
    if (width <= 0)
        return;
    
    ymax = y + height - 1;
    if (ymax >= LCD_HEIGHT)
        ymax = LCD_HEIGHT - 1;

#if defined(IPOD_MINI) || defined(IPOD_MINI2G)
    x += pix_offset;
#endif
     /* writing is done in 16-bit units (8 pixels) */
    xmax = (x + width - 1) >> 3;
    x >>= 3;
    width = xmax - x + 1;

    for (; y <= ymax; y++) {
        unsigned char *data, *data_end;

        lcd_cmd_and_data(R_RAM_ADDR_SET, (y << 5) + addr_offset - x);
        lcd_prepare_cmd(R_RAM_DATA);

        data = &lcd_framebuffer[y][2*x];
        data_end = data + 2 * width;
#if defined(IPOD_MINI) || defined(IPOD_MINI2G)
        if (pix_offset == -2) {
            unsigned cur_word = *data++;
            do {
                cur_word = (cur_word << 8) | *data++;
                cur_word = (cur_word << 8) | *data++;
                lcd_send_data((cur_word >> 4) & 0xffff);
            } while (data <= data_end);
        } else
#endif
        {
            do {
                unsigned highbyte = *data++;
                lcd_send_data((highbyte << 8) | *data++);
            } while (data < data_end);
        }
    }
}

/* Update the display. */
void lcd_update(void)
{
    lcd_update_rect(0, 0, LCD_WIDTH, LCD_HEIGHT);
}

#else

#define IPOD_LCD_BASE           0x70008a0c
#define IPOD_LCD_BUSY_MASK      0x80000000

/* LCD command codes for HD66789R */
#define LCD_CNTL_RAM_ADDR_SET           0x21
#define LCD_CNTL_WRITE_TO_GRAM          0x22
#define LCD_CNTL_HORIZ_RAM_ADDR_POS     0x44
#define LCD_CNTL_VERT_RAM_ADDR_POS      0x45

/*** globals ***/
static int lcd_type = 1; /* 0 = "old" Color/Photo, 1 = "new" Color & Nano */

static void lcd_wait_write(void)
{
    if ((inl(IPOD_LCD_BASE) & IPOD_LCD_BUSY_MASK) != 0) {
        int start = USEC_TIMER;

        do {
            if ((inl(IPOD_LCD_BASE) & IPOD_LCD_BUSY_MASK) == 0) break;
        } while (timer_check(start, 1000) == 0);
    }
}

static void lcd_send_lo(int v)
{
    lcd_wait_write();
    outl(v | 0x80000000, IPOD_LCD_BASE);
}

static void lcd_send_hi(int v)
{
    lcd_wait_write();
    outl(v | 0x81000000, IPOD_LCD_BASE);
}

static void lcd_cmd_data(int cmd, int data)
{
    if (lcd_type == 0) {
        lcd_send_lo(cmd);
        lcd_send_lo(data);
    } else {
        lcd_send_lo(0x0);
        lcd_send_lo(cmd);
        lcd_send_hi((data >> 8) & 0xff);
        lcd_send_hi(data & 0xff);
    }
}

/*** hardware configuration ***/

void lcd_set_contrast(int val)
{
  /* TODO: Implement lcd_set_contrast() */
  (void)val;
}

void lcd_set_invert_display(bool yesno)
{
  /* TODO: Implement lcd_set_invert_display() */
  (void)yesno;
}

/* turn the display upside down (call lcd_update() afterwards) */
void lcd_set_flip(bool yesno)
{
  /* TODO: Implement lcd_set_flip() */
  (void)yesno;
}

/* LCD init */
void lcd_init_device(void)
{  
#if CONFIG_LCD == LCD_IPODCOLOR
    if (ipod_hw_rev == 0x60000) {
        lcd_type = 0;
    } else {
        int gpio_a01, gpio_a04;

        /* A01 */
        gpio_a01 = (inl(0x6000D030) & 0x2) >> 1;
        /* A04 */
        gpio_a04 = (inl(0x6000D030) & 0x10) >> 4;

        if (((gpio_a01 << 1) | gpio_a04) == 0 || ((gpio_a01 << 1) | gpio_a04) == 2) {
            lcd_type = 0;
        } else {
            lcd_type = 1;
        }
    }

    outl(inl(0x6000d004) | 0x4, 0x6000d004); /* B02 enable */
    outl(inl(0x6000d004) | 0x8, 0x6000d004); /* B03 enable */
    outl(inl(0x70000084) | 0x2000000, 0x70000084); /* D01 enable */
    outl(inl(0x70000080) | 0x2000000, 0x70000080); /* D01 =1 */

    outl(inl(0x6000600c) | 0x20000, 0x6000600c);    /* PWM enable */

#elif CONFIG_LCD == LCD_IPODNANO
    /* iPodLinux doesn't appear have any LCD init code for the Nano */
#endif
}

/*** update functions ***/

/* Performance function that works with an external buffer
   note that by and bheight are in 4-pixel units! */
void lcd_blit(const fb_data* data, int x, int by, int width,
              int bheight, int stride)
{
    /* TODO: Implement lcd_blit() */
    (void)data;
    (void)x;
    (void)by;
    (void)width;
    (void)bheight;
    (void)stride;
}

#define CSUB_X 2
#define CSUB_Y 2

#define RYFAC (31*257)
#define GYFAC (31*257)
#define BYFAC (31*257)
#define RVFAC 11170     /* 31 * 257 *  1.402    */
#define GVFAC (-5690)  /* 31 * 257 * -0.714136 */
#define GUFAC (-2742)   /* 31 * 257 * -0.344136 */
#define BUFAC 14118     /* 31 * 257 *  1.772    */

#define ROUNDOFFS (127*257)
#define ROUNDOFFSG (63*257)

/* Performance function to blit a YUV bitmap directly to the LCD */
void lcd_yuv_blit(unsigned char * const src[3],
                  int src_x, int src_y, int stride,
                  int x, int y, int width, int height)
{
    int h;
    int y0, x0, y1, x1;

    width = (width + 1) & ~1;

    /* calculate the drawing region */
#if CONFIG_LCD == LCD_IPODNANO
    y0 = x;                         /* start horiz */
    x0 = y;                         /* start vert */
    y1 = (x + width) - 1;           /* max horiz */
    x1 = (y + height) - 1;          /* max vert */
#elif CONFIG_LCD == LCD_IPODCOLOR
    y0 = y;                         /* start vert */
    x0 = (LCD_WIDTH - 1) - x;       /* start horiz */
    y1 = (y + height) - 1;          /* end vert */
    x1 = (x0 - width) + 1;          /* end horiz */
#endif

    /* setup the drawing region */
    if (lcd_type == 0) {
        lcd_cmd_data(0x12, y0);      /* start vert */
        lcd_cmd_data(0x13, x0);      /* start horiz */
        lcd_cmd_data(0x15, y1);      /* end vert */
        lcd_cmd_data(0x16, x1);      /* end horiz */
    } else {
        /* swap max horiz < start horiz */
        if (y1 < y0) {
            int t;
            t = y0;
            y0 = y1;
            y1 = t;
        }

        /* swap max vert < start vert */
        if (x1 < x0) {
            int t;
            t = x0;
            x0 = x1;
            x1 = t;
        }

        /* max horiz << 8 | start horiz */
        lcd_cmd_data(LCD_CNTL_HORIZ_RAM_ADDR_POS, (y1 << 8) | y0);
        /* max vert << 8 | start vert */
        lcd_cmd_data(LCD_CNTL_VERT_RAM_ADDR_POS, (x1 << 8) | x0);

        /* start vert = max vert */
#if CONFIG_LCD == LCD_IPODCOLOR
        x0 = x1;
#endif

        /* position cursor (set AD0-AD15) */
        /* start vert << 8 | start horiz */
        lcd_cmd_data(LCD_CNTL_RAM_ADDR_SET, ((x0 << 8) | y0));

        /* start drawing */
        lcd_send_lo(0x0);
        lcd_send_lo(LCD_CNTL_WRITE_TO_GRAM);
    }

    const int stride_div_csub_x = stride/CSUB_X;

    h=0;
    while (1) {
        /* upsampling, YUV->RGB conversion and reduction to RGB565 in one go */
        const unsigned char *ysrc = src[0] + stride * src_y + src_x;

        const int uvoffset = stride_div_csub_x * (src_y/CSUB_Y) +
                             (src_x/CSUB_X);

        const unsigned char *usrc = src[1] + uvoffset;
        const unsigned char *vsrc = src[2] + uvoffset;
        const unsigned char *row_end = ysrc + width;

        int y, u, v;
        int red1, green1, blue1;
        int red2, green2, blue2;
        unsigned rbits, gbits, bbits;

        int rc, gc, bc;
        int pixels_to_write;
        fb_data pixel1,pixel2;

        if (h==0) {
            while ((inl(0x70008a20) & 0x4000000) == 0);
            outl(0x0, 0x70008a24);

            if (height == 0) break;

            pixels_to_write = (width * height) * 2;
            h = height;

            /* calculate how much we can do in one go */
            if (pixels_to_write > 0x10000) {
                h = (0x10000/2) / width;
                pixels_to_write = (width * h) * 2;
            }

            height -= h;
            outl(0x10000080, 0x70008a20);
            outl((pixels_to_write - 1) | 0xc0010000, 0x70008a24);
            outl(0x34000000, 0x70008a20);
        }

        do
        {
            u = *usrc++ - 128;
            v = *vsrc++ - 128;
            rc = RVFAC * v + ROUNDOFFS;
            gc = GVFAC * v + GUFAC * u + ROUNDOFFSG;
            bc = BUFAC * u + ROUNDOFFS;

            /* Pixel 1 */
            y = *ysrc++;

            red1   = RYFAC * y + rc;
            green1 = GYFAC * y + gc;
            blue1  = BYFAC * y + bc;

            /* Pixel 2 */
            y = *ysrc++;
            red2   = RYFAC * y + rc;
            green2 = GYFAC * y + gc;
            blue2  = BYFAC * y + bc;

            /* Since out of bounds errors are relatively rare, we check two
               pixels at once to see if any components are out of bounds, and
               then fix whichever is broken. This works due to high values and
               negative values both becoming larger than the cutoff when
               casted to unsigned.  And ORing them together checks all of them
               simultaneously.  */
            if (((unsigned)(red1 | green1 | blue1 |
                     red2 | green2 | blue2)) > (RYFAC*255+ROUNDOFFS)) {
                if (((unsigned)(red1 | green1 | blue1)) > 
                    (RYFAC*255+ROUNDOFFS)) {
                    if ((unsigned)red1 > (RYFAC*255+ROUNDOFFS))
                    {
                        if (red1 < 0)
                            red1 = 0;
                        else
                            red1 = (RYFAC*255+ROUNDOFFS);
                    }
                    if ((unsigned)green1 > (GYFAC*255+ROUNDOFFSG))
                    {
                        if (green1 < 0)
                            green1 = 0;
                        else
                            green1 = (GYFAC*255+ROUNDOFFSG);
                    }
                    if ((unsigned)blue1 > (BYFAC*255+ROUNDOFFS))
                    {
                        if (blue1 < 0)
                            blue1 = 0;
                        else
                            blue1 = (BYFAC*255+ROUNDOFFS);
                    }
                }

                if (((unsigned)(red2 | green2 | blue2)) > 
                    (RYFAC*255+ROUNDOFFS)) {
                    if ((unsigned)red2 > (RYFAC*255+ROUNDOFFS))
                    {
                        if (red2 < 0)
                            red2 = 0;
                        else
                            red2 = (RYFAC*255+ROUNDOFFS);
                    }
                    if ((unsigned)green2 > (GYFAC*255+ROUNDOFFSG))
                    {
                        if (green2 < 0)
                            green2 = 0;
                        else
                            green2 = (GYFAC*255+ROUNDOFFSG);
                    }
                    if ((unsigned)blue2 > (BYFAC*255+ROUNDOFFS))
                    {
                        if (blue2 < 0)
                            blue2 = 0;
                        else
                            blue2 = (BYFAC*255+ROUNDOFFS);
                    }
                }
            }
                
            rbits = red1 >> 16 ;
            gbits = green1 >> 15 ;
            bbits = blue1 >> 16 ;

            pixel1 = swap16((rbits << 11) | (gbits << 5) | bbits);

            rbits = red2 >> 16 ;
            gbits = green2 >> 15 ;
            bbits = blue2 >> 16 ;
            pixel2 = swap16((rbits << 11) | (gbits << 5) | bbits);

            while ((inl(0x70008a20) & 0x1000000) == 0);

            /* output 2 pixels */
            outl((pixel2<<16)|pixel1, 0x70008b00);
        }
        while (ysrc < row_end);

        src_y++;
        h--;
    }

    while ((inl(0x70008a20) & 0x4000000) == 0);
    outl(0x0, 0x70008a24);
}


/* Update a fraction of the display. */
void lcd_update_rect(int x, int y, int width, int height)
{
    int y0, x0, y1, x1;
    int newx,newwidth;

    unsigned long *addr = (unsigned long *)lcd_framebuffer;

    /* Ensure x and width are both even - so we can read 32-bit aligned 
       data from lcd_framebuffer */
    newx=x&~1;
    newwidth=width&~1;
    if (newx+newwidth < x+width) { newwidth+=2; }
    x=newx; width=newwidth;

    /* calculate the drawing region */
#if CONFIG_LCD == LCD_IPODNANO
    y0 = x;                         /* start horiz */
    x0 = y;                         /* start vert */
    y1 = (x + width) - 1;           /* max horiz */
    x1 = (y + height) - 1;          /* max vert */
#elif CONFIG_LCD == LCD_IPODCOLOR
    y0 = y;                         /* start vert */
    x0 = (LCD_WIDTH - 1) - x;       /* start horiz */
    y1 = (y + height) - 1;          /* end vert */
    x1 = (x0 - width) + 1;          /* end horiz */
#endif
    /* setup the drawing region */
    if (lcd_type == 0) {
        lcd_cmd_data(0x12, y0);      /* start vert */
        lcd_cmd_data(0x13, x0);      /* start horiz */
        lcd_cmd_data(0x15, y1);      /* end vert */
        lcd_cmd_data(0x16, x1);      /* end horiz */
    } else {
        /* swap max horiz < start horiz */
        if (y1 < y0) {
            int t;
            t = y0;
            y0 = y1;
            y1 = t;
        }

        /* swap max vert < start vert */
        if (x1 < x0) {
            int t;
            t = x0;
            x0 = x1;
            x1 = t;
        }

        /* max horiz << 8 | start horiz */
        lcd_cmd_data(LCD_CNTL_HORIZ_RAM_ADDR_POS, (y1 << 8) | y0);
        /* max vert << 8 | start vert */
        lcd_cmd_data(LCD_CNTL_VERT_RAM_ADDR_POS, (x1 << 8) | x0);

        /* start vert = max vert */
#if CONFIG_LCD == LCD_IPODCOLOR
        x0 = x1;
#endif

        /* position cursor (set AD0-AD15) */
        /* start vert << 8 | start horiz */
        lcd_cmd_data(LCD_CNTL_RAM_ADDR_SET, ((x0 << 8) | y0));

        /* start drawing */
        lcd_send_lo(0x0);
        lcd_send_lo(LCD_CNTL_WRITE_TO_GRAM);
    }

    addr = (unsigned long*)&lcd_framebuffer[y][x];

    while (height > 0) {
        int c, r;
        int h, pixels_to_write;

        pixels_to_write = (width * height) * 2;
        h = height;

        /* calculate how much we can do in one go */
        if (pixels_to_write > 0x10000) {
            h = (0x10000/2) / width;
            pixels_to_write = (width * h) * 2;
        }

        outl(0x10000080, 0x70008a20);
        outl((pixels_to_write - 1) | 0xc0010000, 0x70008a24);
        outl(0x34000000, 0x70008a20);

        /* for each row */
        for (r = 0; r < h; r++) {
            /* for each column */
            for (c = 0; c < width; c += 2) {
                while ((inl(0x70008a20) & 0x1000000) == 0);

                /* output 2 pixels */
                outl(*(addr++), 0x70008b00);
            }

            addr += (LCD_WIDTH - width)/2;
        }

        while ((inl(0x70008a20) & 0x4000000) == 0);

        outl(0x0, 0x70008a24);

        height = height - h;
    }
}

/* Update the display.
   This must be called after all other LCD functions that change the display. */
void lcd_update(void)
{
    lcd_update_rect(0, 0, LCD_WIDTH, LCD_HEIGHT);
}

#endif