#define DEBUG_VERB 2 /* * Copyright © 2002 David Dawes * * 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 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. * * Except as contained in this notice, the name of the author(s) shall * not be used in advertising or otherwise to promote the sale, use or other * dealings in this Software without prior written authorization from * the author(s). * * Authors: David Dawes * * $XFree86: xc/programs/Xserver/hw/xfree86/os-support/vbe/vbeModes.c,v 1.6 2002/11/02 01:38:25 dawes Exp $ */ /* * Modified by Alan Hourihane * to support extended BIOS modes for the Intel chipsets */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include "xf86.h" #include "vbe.h" #include "vbeModes.h" #include "i830.h" #include "i830_xf86Modes.h" #include #define rint(x) floor(x) #define MARGIN_PERCENT 1.8 /* % of active vertical image */ #define CELL_GRAN 8.0 /* assumed character cell granularity */ #define MIN_PORCH 1 /* minimum front porch */ #define V_SYNC_RQD 3 /* width of vsync in lines */ #define H_SYNC_PERCENT 8.0 /* width of hsync as % of total line */ #define MIN_VSYNC_PLUS_BP 550.0 /* min time of vsync + back porch (microsec) */ #define M 600.0 /* blanking formula gradient */ #define C 40.0 /* blanking formula offset */ #define K 128.0 /* blanking formula scaling factor */ #define J 20.0 /* blanking formula scaling factor */ /* C' and M' are part of the Blanking Duty Cycle computation */ #define C_PRIME (((C - J) * K/256.0) + J) #define M_PRIME (K/256.0 * M) extern const int i830refreshes[]; DisplayModePtr i830GetGTF(int h_pixels, int v_lines, float freq, int interlaced, int margins) { float h_pixels_rnd; float v_lines_rnd; float v_field_rate_rqd; float top_margin; float bottom_margin; float interlace; float h_period_est; float vsync_plus_bp; float v_back_porch; float total_v_lines; float v_field_rate_est; float h_period; float v_field_rate; float v_frame_rate; float left_margin; float right_margin; float total_active_pixels; float ideal_duty_cycle; float h_blank; float total_pixels; float pixel_freq; float h_freq; float h_sync; float h_front_porch; float v_odd_front_porch_lines; DisplayModePtr m; m = xnfcalloc(sizeof(DisplayModeRec), 1); /* 1. In order to give correct results, the number of horizontal * pixels requested is first processed to ensure that it is divisible * by the character size, by rounding it to the nearest character * cell boundary: * * [H PIXELS RND] = ((ROUND([H PIXELS]/[CELL GRAN RND],0))*[CELLGRAN RND]) */ h_pixels_rnd = rint((float) h_pixels / CELL_GRAN) * CELL_GRAN; /* 2. If interlace is requested, the number of vertical lines assumed * by the calculation must be halved, as the computation calculates * the number of vertical lines per field. In either case, the * number of lines is rounded to the nearest integer. * * [V LINES RND] = IF([INT RQD?]="y", ROUND([V LINES]/2,0), * ROUND([V LINES],0)) */ v_lines_rnd = interlaced ? rint((float) v_lines) / 2.0 : rint((float) v_lines); /* 3. Find the frame rate required: * * [V FIELD RATE RQD] = IF([INT RQD?]="y", [I/P FREQ RQD]*2, * [I/P FREQ RQD]) */ v_field_rate_rqd = interlaced ? (freq * 2.0) : (freq); /* 4. Find number of lines in Top margin: * * [TOP MARGIN (LINES)] = IF([MARGINS RQD?]="Y", * ROUND(([MARGIN%]/100*[V LINES RND]),0), * 0) */ top_margin = margins ? rint(MARGIN_PERCENT / 100.0 * v_lines_rnd) : (0.0); /* 5. Find number of lines in Bottom margin: * * [BOT MARGIN (LINES)] = IF([MARGINS RQD?]="Y", * ROUND(([MARGIN%]/100*[V LINES RND]),0), * 0) */ bottom_margin = margins ? rint(MARGIN_PERCENT/100.0 * v_lines_rnd) : (0.0); /* 6. If interlace is required, then set variable [INTERLACE]=0.5: * * [INTERLACE]=(IF([INT RQD?]="y",0.5,0)) */ interlace = interlaced ? 0.5 : 0.0; /* 7. Estimate the Horizontal period * * [H PERIOD EST] = ((1/[V FIELD RATE RQD]) - [MIN VSYNC+BP]/1000000) / * ([V LINES RND] + (2*[TOP MARGIN (LINES)]) + * [MIN PORCH RND]+[INTERLACE]) * 1000000 */ h_period_est = (((1.0/v_field_rate_rqd) - (MIN_VSYNC_PLUS_BP/1000000.0)) / (v_lines_rnd + (2*top_margin) + MIN_PORCH + interlace) * 1000000.0); /* 8. Find the number of lines in V sync + back porch: * * [V SYNC+BP] = ROUND(([MIN VSYNC+BP]/[H PERIOD EST]),0) */ vsync_plus_bp = rint(MIN_VSYNC_PLUS_BP/h_period_est); /* 9. Find the number of lines in V back porch alone: * * [V BACK PORCH] = [V SYNC+BP] - [V SYNC RND] * * XXX is "[V SYNC RND]" a typo? should be [V SYNC RQD]? */ v_back_porch = vsync_plus_bp - V_SYNC_RQD; /* 10. Find the total number of lines in Vertical field period: * * [TOTAL V LINES] = [V LINES RND] + [TOP MARGIN (LINES)] + * [BOT MARGIN (LINES)] + [V SYNC+BP] + [INTERLACE] + * [MIN PORCH RND] */ total_v_lines = v_lines_rnd + top_margin + bottom_margin + vsync_plus_bp + interlace + MIN_PORCH; /* 11. Estimate the Vertical field frequency: * * [V FIELD RATE EST] = 1 / [H PERIOD EST] / [TOTAL V LINES] * 1000000 */ v_field_rate_est = 1.0 / h_period_est / total_v_lines * 1000000.0; /* 12. Find the actual horizontal period: * * [H PERIOD] = [H PERIOD EST] / ([V FIELD RATE RQD] / [V FIELD RATE EST]) */ h_period = h_period_est / (v_field_rate_rqd / v_field_rate_est); /* 13. Find the actual Vertical field frequency: * * [V FIELD RATE] = 1 / [H PERIOD] / [TOTAL V LINES] * 1000000 */ v_field_rate = 1.0 / h_period / total_v_lines * 1000000.0; /* 14. Find the Vertical frame frequency: * * [V FRAME RATE] = (IF([INT RQD?]="y", [V FIELD RATE]/2, [V FIELD RATE])) */ v_frame_rate = interlaced ? v_field_rate / 2.0 : v_field_rate; /* 15. Find number of pixels in left margin: * * [LEFT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y", * (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 / * [CELL GRAN RND]),0)) * [CELL GRAN RND], * 0)) */ left_margin = margins ? rint(h_pixels_rnd * MARGIN_PERCENT / 100.0 / CELL_GRAN) * CELL_GRAN : 0.0; /* 16. Find number of pixels in right margin: * * [RIGHT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y", * (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 / * [CELL GRAN RND]),0)) * [CELL GRAN RND], * 0)) */ right_margin = margins ? rint(h_pixels_rnd * MARGIN_PERCENT / 100.0 / CELL_GRAN) * CELL_GRAN : 0.0; /* 17. Find total number of active pixels in image and left and right * margins: * * [TOTAL ACTIVE PIXELS] = [H PIXELS RND] + [LEFT MARGIN (PIXELS)] + * [RIGHT MARGIN (PIXELS)] */ total_active_pixels = h_pixels_rnd + left_margin + right_margin; /* 18. Find the ideal blanking duty cycle from the blanking duty cycle * equation: * * [IDEAL DUTY CYCLE] = [C'] - ([M']*[H PERIOD]/1000) */ ideal_duty_cycle = C_PRIME - (M_PRIME * h_period / 1000.0); /* 19. Find the number of pixels in the blanking time to the nearest * double character cell: * * [H BLANK (PIXELS)] = (ROUND(([TOTAL ACTIVE PIXELS] * * [IDEAL DUTY CYCLE] / * (100-[IDEAL DUTY CYCLE]) / * (2*[CELL GRAN RND])), 0)) * * (2*[CELL GRAN RND]) */ h_blank = rint(total_active_pixels * ideal_duty_cycle / (100.0 - ideal_duty_cycle) / (2.0 * CELL_GRAN)) * (2.0 * CELL_GRAN); /* 20. Find total number of pixels: * * [TOTAL PIXELS] = [TOTAL ACTIVE PIXELS] + [H BLANK (PIXELS)] */ total_pixels = total_active_pixels + h_blank; /* 21. Find pixel clock frequency: * * [PIXEL FREQ] = [TOTAL PIXELS] / [H PERIOD] */ pixel_freq = total_pixels / h_period; /* 22. Find horizontal frequency: * * [H FREQ] = 1000 / [H PERIOD] */ h_freq = 1000.0 / h_period; /* Stage 1 computations are now complete; I should really pass the results to another function and do the Stage 2 computations, but I only need a few more values so I'll just append the computations here for now */ /* 17. Find the number of pixels in the horizontal sync period: * * [H SYNC (PIXELS)] =(ROUND(([H SYNC%] / 100 * [TOTAL PIXELS] / * [CELL GRAN RND]),0))*[CELL GRAN RND] */ h_sync = rint(H_SYNC_PERCENT/100.0 * total_pixels / CELL_GRAN) * CELL_GRAN; /* 18. Find the number of pixels in the horizontal front porch period: * * [H FRONT PORCH (PIXELS)] = ([H BLANK (PIXELS)]/2)-[H SYNC (PIXELS)] */ h_front_porch = (h_blank / 2.0) - h_sync; /* 36. Find the number of lines in the odd front porch period: * * [V ODD FRONT PORCH(LINES)]=([MIN PORCH RND]+[INTERLACE]) */ v_odd_front_porch_lines = MIN_PORCH + interlace; /* finally, pack the results in the DisplayMode struct */ m->HDisplay = (int) (h_pixels_rnd); m->HSyncStart = (int) (h_pixels_rnd + h_front_porch); m->HSyncEnd = (int) (h_pixels_rnd + h_front_porch + h_sync); m->HTotal = (int) (total_pixels); m->VDisplay = (int) (v_lines_rnd); m->VSyncStart = (int) (v_lines_rnd + v_odd_front_porch_lines); m->VSyncEnd = (int) (int) (v_lines_rnd + v_odd_front_porch_lines + V_SYNC_RQD); m->VTotal = (int) (total_v_lines); m->Clock = (int)(pixel_freq * 1000); m->SynthClock = m->Clock; m->HSync = h_freq; m->VRefresh = v_frame_rate /* freq */; i830xf86SetModeDefaultName(m); return (m); }