diff options
Diffstat (limited to 'xorg-server/hw/xfree86/modes/xf86cvt.c')
| -rw-r--r-- | xorg-server/hw/xfree86/modes/xf86cvt.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/xorg-server/hw/xfree86/modes/xf86cvt.c b/xorg-server/hw/xfree86/modes/xf86cvt.c new file mode 100644 index 000000000..e9c74aa62 --- /dev/null +++ b/xorg-server/hw/xfree86/modes/xf86cvt.c @@ -0,0 +1,301 @@ +/* + * Copyright 2005-2006 Luc Verhaegen. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ + +/* + * The reason for having this function in a file of its own is + * so that ../utils/cvt/cvt can link to it, and that xf86CVTMode + * code is shared directly. + */ + +#ifdef HAVE_XORG_CONFIG_H +#include <xorg-config.h> +#else +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#endif + +#include "xf86.h" +#include "xf86Modes.h" + +#include <string.h> + +/* + * Generate a CVT standard mode from HDisplay, VDisplay and VRefresh. + * + * These calculations are stolen from the CVT calculation spreadsheet written + * by Graham Loveridge. He seems to be claiming no copyright and there seems to + * be no license attached to this. He apparently just wants to see his name + * mentioned. + * + * This file can be found at http://www.vesa.org/Public/CVT/CVTd6r1.xls + * + * Comments and structure corresponds to the comments and structure of the xls. + * This should ease importing of future changes to the standard (not very + * likely though). + * + * About margins; i'm sure that they are to be the bit between HDisplay and + * HBlankStart, HBlankEnd and HTotal, VDisplay and VBlankStart, VBlankEnd and + * VTotal, where the overscan colour is shown. FB seems to call _all_ blanking + * outside sync "margin" for some reason. Since we prefer seeing proper + * blanking instead of the overscan colour, and since the Crtc* values will + * probably get altered after us, we will disable margins altogether. With + * these calculations, Margins will plainly expand H/VDisplay, and we don't + * want that. -- libv + * + */ +_X_EXPORT DisplayModePtr +xf86CVTMode(int HDisplay, int VDisplay, float VRefresh, Bool Reduced, + Bool Interlaced) +{ + DisplayModeRec *Mode = xnfcalloc(1, sizeof(DisplayModeRec)); + + /* 1) top/bottom margin size (% of height) - default: 1.8 */ +#define CVT_MARGIN_PERCENTAGE 1.8 + + /* 2) character cell horizontal granularity (pixels) - default 8 */ +#define CVT_H_GRANULARITY 8 + + /* 4) Minimum vertical porch (lines) - default 3 */ +#define CVT_MIN_V_PORCH 3 + + /* 4) Minimum number of vertical back porch lines - default 6 */ +#define CVT_MIN_V_BPORCH 6 + + /* Pixel Clock step (kHz) */ +#define CVT_CLOCK_STEP 250 + + Bool Margins = FALSE; + float VFieldRate, HPeriod; + int HDisplayRnd, HMargin; + int VDisplayRnd, VMargin, VSync; + float Interlace; /* Please rename this */ + + /* CVT default is 60.0Hz */ + if (!VRefresh) + VRefresh = 60.0; + + /* 1. Required field rate */ + if (Interlaced) + VFieldRate = VRefresh * 2; + else + VFieldRate = VRefresh; + + /* 2. Horizontal pixels */ + HDisplayRnd = HDisplay - (HDisplay % CVT_H_GRANULARITY); + + /* 3. Determine left and right borders */ + if (Margins) { + /* right margin is actually exactly the same as left */ + HMargin = (((float) HDisplayRnd) * CVT_MARGIN_PERCENTAGE / 100.0); + HMargin -= HMargin % CVT_H_GRANULARITY; + } else + HMargin = 0; + + /* 4. Find total active pixels */ + Mode->HDisplay = HDisplayRnd + 2*HMargin; + + /* 5. Find number of lines per field */ + if (Interlaced) + VDisplayRnd = VDisplay / 2; + else + VDisplayRnd = VDisplay; + + /* 6. Find top and bottom margins */ + /* nope. */ + if (Margins) + /* top and bottom margins are equal again. */ + VMargin = (((float) VDisplayRnd) * CVT_MARGIN_PERCENTAGE / 100.0); + else + VMargin = 0; + + Mode->VDisplay = VDisplay + 2*VMargin; + + /* 7. Interlace */ + if (Interlaced) + Interlace = 0.5; + else + Interlace = 0.0; + + /* Determine VSync Width from aspect ratio */ + if (!(VDisplay % 3) && ((VDisplay * 4 / 3) == HDisplay)) + VSync = 4; + else if (!(VDisplay % 9) && ((VDisplay * 16 / 9) == HDisplay)) + VSync = 5; + else if (!(VDisplay % 10) && ((VDisplay * 16 / 10) == HDisplay)) + VSync = 6; + else if (!(VDisplay % 4) && ((VDisplay * 5 / 4) == HDisplay)) + VSync = 7; + else if (!(VDisplay % 9) && ((VDisplay * 15 / 9) == HDisplay)) + VSync = 7; + else /* Custom */ + VSync = 10; + + if (!Reduced) { /* simplified GTF calculation */ + + /* 4) Minimum time of vertical sync + back porch interval (µs) + * default 550.0 */ +#define CVT_MIN_VSYNC_BP 550.0 + + /* 3) Nominal HSync width (% of line period) - default 8 */ +#define CVT_HSYNC_PERCENTAGE 8 + + float HBlankPercentage; + int VSyncAndBackPorch, VBackPorch; + int HBlank; + + /* 8. Estimated Horizontal period */ + 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)) + VSyncAndBackPorch = VSync + CVT_MIN_V_PORCH; + else + VSyncAndBackPorch = (int)(CVT_MIN_VSYNC_BP / HPeriod) + 1; + + /* 10. Find number of lines in back porch */ + VBackPorch = VSyncAndBackPorch - VSync; + + /* 11. Find total number of lines in vertical field */ + Mode->VTotal = VDisplayRnd + 2 * VMargin + VSyncAndBackPorch + Interlace + + CVT_MIN_V_PORCH; + + /* 5) Definition of Horizontal blanking time limitation */ + /* Gradient (%/kHz) - default 600 */ +#define CVT_M_FACTOR 600 + + /* Offset (%) - default 40 */ +#define CVT_C_FACTOR 40 + + /* Blanking time scaling factor - default 128 */ +#define CVT_K_FACTOR 128 + + /* Scaling factor weighting - default 20 */ +#define CVT_J_FACTOR 20 + +#define CVT_M_PRIME CVT_M_FACTOR * CVT_K_FACTOR / 256 +#define CVT_C_PRIME (CVT_C_FACTOR - CVT_J_FACTOR) * CVT_K_FACTOR / 256 + \ + CVT_J_FACTOR + + /* 12. Find ideal blanking duty cycle from formula */ + 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); + + /* 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->HTotal * CVT_HSYNC_PERCENTAGE) / 100; + 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 */ + /* Minimum vertical blanking interval time (µs) - default 460 */ +#define CVT_RB_MIN_VBLANK 460.0 + + /* Fixed number of clocks for horizontal sync */ +#define CVT_RB_H_SYNC 32.0 + + /* Fixed number of clocks for horizontal blanking */ +#define CVT_RB_H_BLANK 160.0 + + /* Fixed number of lines for vertical front porch - default 3 */ +#define CVT_RB_VFPORCH 3 + + int VBILines; + + /* 8. Estimate Horizontal period. */ + 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; + + /* 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; + + /* 12. Find total number of pixels in a line */ + Mode->HTotal = Mode->HDisplay + CVT_RB_H_BLANK; + + /* Fill in HSync values */ + Mode->HSyncEnd = Mode->HDisplay + CVT_RB_H_BLANK / 2; + Mode->HSyncStart = Mode->HSyncEnd - CVT_RB_H_SYNC; + + /* Fill in VSync values */ + Mode->VSyncStart = Mode->VDisplay + CVT_RB_VFPORCH; + Mode->VSyncEnd = Mode->VSyncStart + VSync; + } + + /* 15/13. Find pixel clock frequency (kHz for xf86) */ + Mode->Clock = Mode->HTotal * 1000.0 / HPeriod; + Mode->Clock -= Mode->Clock % CVT_CLOCK_STEP; + + /* 16/14. Find actual Horizontal Frequency (kHz) */ + Mode->HSync = ((float) Mode->Clock) / ((float) Mode->HTotal); + + /* 17/15. Find actual Field rate */ + Mode->VRefresh = (1000.0 * ((float) Mode->Clock)) / + ((float) (Mode->HTotal * Mode->VTotal)); + + /* 18/16. Find actual vertical frame frequency */ + /* ignore - just set the mode flag for interlaced */ + if (Interlaced) + Mode->VTotal *= 2; + + { + char Name[256]; + Name[0] = 0; + + snprintf(Name, 256, "%dx%d", HDisplay, VDisplay); + + Mode->name = xnfalloc(strlen(Name) + 1); + memcpy(Mode->name, Name, strlen(Name) + 1); + } + + if (Reduced) + Mode->Flags |= V_PHSYNC | V_NVSYNC; + else + Mode->Flags |= V_NHSYNC | V_PVSYNC; + + if (Interlaced) + Mode->Flags |= V_INTERLACE; + + return Mode; +} |