diff options
Diffstat (limited to 'xorg-server/hw/xfree86/modes/xf86cvt.c')
| -rw-r--r-- | xorg-server/hw/xfree86/modes/xf86cvt.c | 63 |
1 files changed, 33 insertions, 30 deletions
diff --git a/xorg-server/hw/xfree86/modes/xf86cvt.c b/xorg-server/hw/xfree86/modes/xf86cvt.c index d5fecccb5..de0784493 100644 --- a/xorg-server/hw/xfree86/modes/xf86cvt.c +++ b/xorg-server/hw/xfree86/modes/xf86cvt.c @@ -65,12 +65,12 @@ */ DisplayModePtr xf86CVTMode(int HDisplay, int VDisplay, float VRefresh, Bool Reduced, - Bool Interlaced) + Bool Interlaced) { - DisplayModeRec *Mode = xnfcalloc(1, sizeof(DisplayModeRec)); + DisplayModeRec *Mode = xnfcalloc(1, sizeof(DisplayModeRec)); /* 1) top/bottom margin size (% of height) - default: 1.8 */ -#define CVT_MARGIN_PERCENTAGE 1.8 +#define CVT_MARGIN_PERCENTAGE 1.8 /* 2) character cell horizontal granularity (pixels) - default 8 */ #define CVT_H_GRANULARITY 8 @@ -85,10 +85,10 @@ xf86CVTMode(int HDisplay, int VDisplay, float VRefresh, Bool Reduced, #define CVT_CLOCK_STEP 250 Bool Margins = FALSE; - float VFieldRate, HPeriod; - int HDisplayRnd, HMargin; - int VDisplayRnd, VMargin, VSync; - float Interlace; /* Please rename this */ + float VFieldRate, HPeriod; + int HDisplayRnd, HMargin; + int VDisplayRnd, VMargin, VSync; + float Interlace; /* Please rename this */ /* CVT default is 60.0Hz */ if (!VRefresh) @@ -108,11 +108,12 @@ xf86CVTMode(int HDisplay, int VDisplay, float VRefresh, Bool Reduced, /* right margin is actually exactly the same as left */ HMargin = (((float) HDisplayRnd) * CVT_MARGIN_PERCENTAGE / 100.0); HMargin -= HMargin % CVT_H_GRANULARITY; - } else + } + else HMargin = 0; /* 4. Find total active pixels */ - Mode->HDisplay = HDisplayRnd + 2*HMargin; + Mode->HDisplay = HDisplayRnd + 2 * HMargin; /* 5. Find number of lines per field */ if (Interlaced) @@ -128,7 +129,7 @@ xf86CVTMode(int HDisplay, int VDisplay, float VRefresh, Bool Reduced, else VMargin = 0; - Mode->VDisplay = VDisplay + 2*VMargin; + Mode->VDisplay = VDisplay + 2 * VMargin; /* 7. Interlace */ if (Interlaced) @@ -147,10 +148,10 @@ xf86CVTMode(int HDisplay, int VDisplay, float VRefresh, Bool Reduced, VSync = 7; else if (!(VDisplay % 9) && ((VDisplay * 15 / 9) == HDisplay)) VSync = 7; - else /* Custom */ + else /* Custom */ VSync = 10; - if (!Reduced) { /* simplified GTF calculation */ + if (!Reduced) { /* simplified GTF calculation */ /* 4) Minimum time of vertical sync + back porch interval (µs) * default 550.0 */ @@ -159,19 +160,20 @@ xf86CVTMode(int HDisplay, int VDisplay, float VRefresh, Bool Reduced, /* 3) Nominal HSync width (% of line period) - default 8 */ #define CVT_HSYNC_PERCENTAGE 8 - float HBlankPercentage; - int VSyncAndBackPorch, VBackPorch; - int HBlank; + float HBlankPercentage; + int VSyncAndBackPorch, VBackPorch; + int HBlank; /* 8. Estimated Horizontal period */ - HPeriod = ((float) (1000000.0 / VFieldRate - CVT_MIN_VSYNC_BP)) / + HPeriod = ((float) (1000000.0 / VFieldRate - CVT_MIN_VSYNC_BP)) / (VDisplayRnd + 2 * VMargin + CVT_MIN_V_PORCH + Interlace); /* 9. Find number of lines in sync + backporch */ - if (((int)(CVT_MIN_VSYNC_BP / HPeriod) + 1) < (VSync + CVT_MIN_V_PORCH)) + if (((int) (CVT_MIN_VSYNC_BP / HPeriod) + 1) < + (VSync + CVT_MIN_V_PORCH)) VSyncAndBackPorch = VSync + CVT_MIN_V_PORCH; else - VSyncAndBackPorch = (int)(CVT_MIN_VSYNC_BP / HPeriod) + 1; + VSyncAndBackPorch = (int) (CVT_MIN_VSYNC_BP / HPeriod) + 1; /* 10. Find number of lines in back porch */ VBackPorch = VSyncAndBackPorch - VSync; @@ -198,31 +200,32 @@ xf86CVTMode(int HDisplay, int VDisplay, float VRefresh, Bool Reduced, CVT_J_FACTOR /* 12. Find ideal blanking duty cycle from formula */ - HBlankPercentage = CVT_C_PRIME - CVT_M_PRIME * HPeriod/1000.0; + HBlankPercentage = CVT_C_PRIME - CVT_M_PRIME * HPeriod / 1000.0; /* 13. Blanking time */ if (HBlankPercentage < 20) HBlankPercentage = 20; - HBlank = Mode->HDisplay * HBlankPercentage/(100.0 - HBlankPercentage); - HBlank -= HBlank % (2*CVT_H_GRANULARITY); - + HBlank = Mode->HDisplay * HBlankPercentage / (100.0 - HBlankPercentage); + HBlank -= HBlank % (2 * CVT_H_GRANULARITY); + /* 14. Find total number of pixels in a line. */ Mode->HTotal = Mode->HDisplay + HBlank; /* Fill in HSync values */ Mode->HSyncEnd = Mode->HDisplay + HBlank / 2; - Mode->HSyncStart = Mode->HSyncEnd - + Mode->HSyncStart = Mode->HSyncEnd - (Mode->HTotal * CVT_HSYNC_PERCENTAGE) / 100; - Mode->HSyncStart += CVT_H_GRANULARITY - + Mode->HSyncStart += CVT_H_GRANULARITY - Mode->HSyncStart % CVT_H_GRANULARITY; /* Fill in VSync values */ Mode->VSyncStart = Mode->VDisplay + CVT_MIN_V_PORCH; Mode->VSyncEnd = Mode->VSyncStart + VSync; - } else { /* Reduced blanking */ + } + else { /* Reduced blanking */ /* Minimum vertical blanking interval time (µs) - default 460 */ #define CVT_RB_MIN_VBLANK 460.0 @@ -235,11 +238,11 @@ xf86CVTMode(int HDisplay, int VDisplay, float VRefresh, Bool Reduced, /* Fixed number of lines for vertical front porch - default 3 */ #define CVT_RB_VFPORCH 3 - int VBILines; + int VBILines; /* 8. Estimate Horizontal period. */ - HPeriod = ((float) (1000000.0 / VFieldRate - CVT_RB_MIN_VBLANK)) / - (VDisplayRnd + 2*VMargin); + HPeriod = ((float) (1000000.0 / VFieldRate - CVT_RB_MIN_VBLANK)) / + (VDisplayRnd + 2 * VMargin); /* 9. Find number of lines in vertical blanking */ VBILines = ((float) CVT_RB_MIN_VBLANK) / HPeriod + 1; @@ -247,7 +250,7 @@ xf86CVTMode(int HDisplay, int VDisplay, float VRefresh, Bool Reduced, /* 10. Check if vertical blanking is sufficient */ if (VBILines < (CVT_RB_VFPORCH + VSync + CVT_MIN_V_BPORCH)) VBILines = CVT_RB_VFPORCH + VSync + CVT_MIN_V_BPORCH; - + /* 11. Find total number of lines in vertical field */ Mode->VTotal = VDisplayRnd + 2 * VMargin + Interlace + VBILines; @@ -271,7 +274,7 @@ xf86CVTMode(int HDisplay, int VDisplay, float VRefresh, Bool Reduced, Mode->HSync = ((float) Mode->Clock) / ((float) Mode->HTotal); /* 17/15. Find actual Field rate */ - Mode->VRefresh = (1000.0 * ((float) Mode->Clock)) / + Mode->VRefresh = (1000.0 * ((float) Mode->Clock)) / ((float) (Mode->HTotal * Mode->VTotal)); /* 18/16. Find actual vertical frame frequency */ |