Rev 54 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 54 | pj | 1 | /* |
| 2 | * btdacs.c: |
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| 3 | * |
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| 4 | * RAMDAC definition for Bt485 |
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| 5 | * |
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| 6 | * NON-FUNCTIONAL |
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| 7 | */ |
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| 8 | |||
| 9 | #include <stdlib.h> |
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| 10 | #include <stdio.h> |
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| 11 | #include "libvga.h" |
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| 12 | |||
| 13 | #include "timing.h" |
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| 14 | #include "vgaregs.h" |
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| 15 | #include "driver.h" /* for __svgalib_driver_report */ |
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| 16 | #include "ramdac.h" |
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| 17 | |||
| 18 | /* |
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| 19 | * RAMDAC definition for industry-standard AT&T20C498 DAC with 16-bit |
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| 20 | * pixel port, and compatibles. |
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| 21 | * Differently rated versions exist, such as 80, 110, 135 and 170 MHz. |
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| 22 | * This code assumes the DAC is actually connected with a 16-bit path. |
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| 23 | * (an example of a 498-compatible DAC being used with a 8-bit path |
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| 24 | * is the Hercules Stingray Pro/V with the IC Works ZoomDAC). |
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| 25 | */ |
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| 26 | |||
| 27 | #ifdef INCLUDE_BT485_DAC_TEST |
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| 28 | static int bt485_probe(void) |
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| 29 | { |
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| 30 | return 0; |
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| 31 | } |
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| 32 | #else |
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| 33 | #define bt485_probe 0 |
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| 34 | #endif |
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| 35 | |||
| 36 | #ifdef INCLUDE_BT485_DAC |
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| 37 | static void bt485_init(void) |
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| 38 | { |
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| 39 | if (__svgalib_driver_report) |
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| 81 | giacomo | 40 | cprintf("svgalib: Using BT485 DAC, 135 MHz rated.\n"); |
| 54 | pj | 41 | } |
| 42 | |||
| 43 | static int bt485_map_clock(int bpp, int pixelclock) |
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| 44 | { |
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| 45 | return pixelclock; |
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| 46 | |||
| 47 | if (bpp == 8 && pixelclock > 80000) |
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| 48 | /* Use 16-bit path, clock doubling at RAMDAC. */ |
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| 49 | return pixelclock / 2; |
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| 50 | if (bpp == 16) |
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| 51 | return pixelclock; |
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| 52 | if (bpp == 32) |
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| 53 | return pixelclock * 2; |
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| 54 | return pixelclock; |
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| 55 | } |
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| 56 | |||
| 57 | static int bt485_map_horizontal_crtc(int bpp, int pixelclock, int htiming) |
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| 58 | { |
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| 59 | return htiming |
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| 60 | |||
| 61 | /* Not sure. */ |
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| 62 | if (bpp == 8 && pixelclock > 80000) |
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| 63 | /* Use 16-bit path, clock doubling at RAMDAC. */ |
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| 64 | return htiming / 2; |
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| 65 | if (bpp == 32) |
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| 66 | return htiming * 2; |
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| 67 | return htiming; |
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| 68 | } |
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| 69 | |||
| 70 | static void bt485_initializestate(unsigned char *regs, int bpp, int colormode, |
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| 71 | int pixelclock) |
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| 72 | { |
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| 73 | regs[0] = 0; |
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| 74 | if (colormode == CLUT8_8) |
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| 75 | regs[0] = 0x02; |
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| 76 | if (colormode == RGB16_555) |
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| 77 | regs[0] = 0x10; |
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| 78 | if (colormode == RGB16_565) |
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| 79 | regs[0] = 0x30; |
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| 80 | if (colormode == RGB32_888_B) |
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| 81 | regs[0] = 0x50; |
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| 82 | } |
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| 83 | |||
| 84 | static void 485_qualify_cardspecs(CardSpecs * cardspecs, int dacspeed) |
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| 85 | { |
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| 86 | dacspeed = __svgalib_setDacSpeed(dacspeed, 135000); |
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| 87 | cardspecs->maxPixelClock4bpp = 0; |
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| 88 | cardspecs->maxPixelClock8bpp = dacspeed; |
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| 89 | cardspecs->maxPixelClock16bpp = dacspeed; |
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| 90 | cardspecs->maxPixelClock24bpp = 0; |
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| 91 | cardspecs->maxPixelClock32bpp = dacspeed ; |
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| 92 | cardspecs->mapClock = bt485_map_clock; |
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| 93 | cardspecs->mapHorizontalCrtc = att20c498_map_horizontal_crtc; |
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| 94 | } |
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| 95 | |||
| 96 | DacMethods __svgalib_BT485_methods = |
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| 97 | { |
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| 98 | BT485, |
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| 99 | "BT485 DAC", |
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| 100 | 0, |
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| 101 | bt485_probe, |
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| 102 | bt485_init, |
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| 103 | bt485_qualify_cardspecs, |
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| 104 | __svgalib_Sierra_32K_savestate, |
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| 105 | __svgalib_Sierra_32K_restorestate, |
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| 106 | bt485_initializestate, |
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| 107 | 1 /* State size. */ |
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| 108 | }; |
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| 109 | #endif |