/*
        Copyright 1999, Be Incorporated.   All Rights Reserved.
        This file may be used under the terms of the Be Sample Code License.

        Other authors for MGA driver:
        Mark Watson,
        Rudolf Cornelissen 9/2002-10/2009
*/

#include <string.h>

#define MODULE_BIT 0x00400000

#include "acc_std.h"

#define T_POSITIVE_SYNC (B_POSITIVE_HSYNC | B_POSITIVE_VSYNC)
/* mode flags will be setup as status info by PROPOSEMODE! */
#define MODE_FLAGS 0
#define MODE_COUNT (sizeof (mode_list) / sizeof (display_mode))

/* Standard VESA modes,
 * plus panel specific resolution modes which are internally modified during run-time depending on the requirements of the actual
 * panel connected. The modes as listed here, should timing-wise be as compatible with analog (CRT) monitors as can be... */
//fixme: if EDID monitor found create list via common EDID code...
static const display_mode mode_list[] = {
/* 4:3 modes; 307.2k pixels */
{ { 25175, 640, 656, 752, 800, 480, 490, 492, 525, 0}, B_CMAP8, 640, 480, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(640X480X8.Z1) */
{ { 27500, 640, 672, 768, 864, 480, 488, 494, 530, 0}, B_CMAP8, 640, 480, 0, 0, MODE_FLAGS}, /* 640X480X60Hz */
{ { 30500, 640, 672, 768, 864, 480, 517, 523, 588, 0}, B_CMAP8, 640, 480, 0, 0, MODE_FLAGS}, /* SVGA_640X480X60HzNI */
{ { 31500, 640, 664, 704, 832, 480, 489, 492, 520, 0}, B_CMAP8, 640, 480, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@70-72Hz_(640X480X8.Z1) */
{ { 31500, 640, 656, 720, 840, 480, 481, 484, 500, 0}, B_CMAP8, 640, 480, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@75Hz_(640X480X8.Z1) */
{ { 36000, 640, 696, 752, 832, 480, 481, 484, 509, 0}, B_CMAP8, 640, 480, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@85Hz_(640X480X8.Z1) */
/* 4:3 modes; 480k pixels */
{ { 36000, 800, 824, 896, 1024, 600, 601, 603, 625, 0}, B_CMAP8, 800, 600, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@56Hz_(800X600) from Be, Inc. driver + XFree86 */
{ { 38100, 800, 832, 960, 1088, 600, 602, 606, 620, 0}, B_CMAP8, 800, 600, 0, 0, MODE_FLAGS}, /* SVGA_800X600X56HzNI */
{ { 40000, 800, 840, 968, 1056, 600, 601, 605, 628, T_POSITIVE_SYNC}, B_CMAP8, 800, 600, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(800X600X8.Z1) + XFree86 */
{ { 49500, 800, 816, 896, 1056, 600, 601, 604, 625, T_POSITIVE_SYNC}, B_CMAP8, 800, 600, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@75Hz_(800X600X8.Z1) + XFree86 */
{ { 50000, 800, 856, 976, 1040, 600, 637, 643, 666, T_POSITIVE_SYNC}, B_CMAP8, 800, 600, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@70-72Hz_(800X600X8.Z1) + XFree86 */
{ { 56250, 800, 832, 896, 1048, 600, 601, 604, 631, T_POSITIVE_SYNC}, B_CMAP8, 800, 600, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@85Hz_(800X600X8.Z1) + XFree86 */
/* 4:3 modes; 786.432k pixels */
{ { 65000, 1024, 1048, 1184, 1344, 768, 771, 777, 806, 0}, B_CMAP8, 1024, 768, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1024X768X8.Z1) + XFree86 */
{ { 75000, 1024, 1048, 1184, 1328, 768, 771, 777, 806, 0}, B_CMAP8, 1024, 768, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@70-72Hz_(1024X768X8.Z1) + XFree86 */
{ { 78750, 1024, 1040, 1136, 1312, 768, 769, 772, 800, T_POSITIVE_SYNC}, B_CMAP8, 1024, 768, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@75Hz_(1024X768X8.Z1) + XFree86 */
{ { 94500, 1024, 1072, 1168, 1376, 768, 769, 772, 808, T_POSITIVE_SYNC}, B_CMAP8, 1024, 768, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@85Hz_(1024X768X8.Z1) + XFree86 */
/* 4:3 modes; 995.328k pixels */
{ { 94200, 1152, 1184, 1280, 1472, 864, 865, 868, 914, T_POSITIVE_SYNC}, B_CMAP8, 1152, 864, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@70Hz_(1152X864X8.Z1) */
{ { 97800, 1152, 1216, 1344, 1552, 864, 865, 868, 900, T_POSITIVE_SYNC}, B_CMAP8, 1152, 864, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@70Hz_(1152X864X8.Z1) */
{ { 108000, 1152, 1216, 1344, 1600, 864, 865, 868, 900, T_POSITIVE_SYNC}, B_CMAP8, 1152, 864, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@75Hz_(1152X864X8.Z1) + XFree86 */
{ { 121500, 1152, 1216, 1344, 1568, 864, 865, 868, 911, T_POSITIVE_SYNC}, B_CMAP8, 1152, 864, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@85Hz_(1152X864X8.Z1) */
/* 5:4 modes; 1.311M pixels */
{ { 108000, 1280, 1328, 1440, 1688, 1024, 1025, 1028, 1066, T_POSITIVE_SYNC}, B_CMAP8, 1280, 1024, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1280X1024) from Be, Inc. driver + XFree86 */
{ { 135000, 1280, 1296, 1440, 1688, 1024, 1025, 1028, 1066, T_POSITIVE_SYNC}, B_CMAP8, 1280, 1024, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@75Hz_(1280X1024X8.Z1) + XFree86 */
{ { 157500, 1280, 1344, 1504, 1728, 1024, 1025, 1028, 1072, T_POSITIVE_SYNC}, B_CMAP8, 1280, 1024, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@85Hz_(1280X1024X8.Z1) + XFree86 */
/* 4:3 panel mode; 1.47M pixels */
{ { 122600, 1400, 1488, 1640, 1880, 1050, 1051, 1054, 1087, T_POSITIVE_SYNC}, B_CMAP8, 1400, 1050, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1400X1050) */
/* 4:3 modes; 1.92M pixels */
{ { 162000, 1600, 1664, 1856, 2160, 1200, 1201, 1204, 1250, T_POSITIVE_SYNC}, B_CMAP8, 1600, 1200, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1600X1200X8.Z1) + XFree86 */
/* identical lines to above one, apart from refreshrate.. */
{ { 175500, 1600, 1664, 1856, 2160, 1200, 1201, 1204, 1250, T_POSITIVE_SYNC}, B_CMAP8, 1600, 1200, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@65Hz_(1600X1200X8.Z1) + XFree86 */
{ { 189000, 1600, 1664, 1856, 2160, 1200, 1201, 1204, 1250, T_POSITIVE_SYNC}, B_CMAP8, 1600, 1200, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@70Hz_(1600X1200X8.Z1) + XFree86 */
{ { 202500, 1600, 1664, 1856, 2160, 1200, 1201, 1204, 1250, T_POSITIVE_SYNC}, B_CMAP8, 1600, 1200, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@75Hz_(1600X1200X8.Z1) + XFree86 */
{ { 216000, 1600, 1664, 1856, 2160, 1200, 1201, 1204, 1250, T_POSITIVE_SYNC}, B_CMAP8, 1600, 1200, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@80Hz_(1600X1200X8.Z1) */
{ { 229500, 1600, 1664, 1856, 2160, 1200, 1201, 1204, 1250, T_POSITIVE_SYNC}, B_CMAP8, 1600, 1200, 0, 0, MODE_FLAGS},  /* Vesa_Monitor_@85Hz_(1600X1200X8.Z1) + XFree86 */
/* end identical lines. */
/* 4:3 modes; 2.408M pixels */
{ { 204750, 1792, 1920, 2120, 2448, 1344, 1345, 1348, 1394, B_POSITIVE_VSYNC}, B_CMAP8, 1792, 1344, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1792X1344) from Be, Inc. driver + XFree86 */
{ { 261000, 1792, 1888, 2104, 2456, 1344, 1345, 1348, 1417, B_POSITIVE_VSYNC}, B_CMAP8, 1792, 1344, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@75Hz_(1792X1344) from Be, Inc. driver + XFree86 */
/* 4:3 modes; 2.584M pixels */
{ { 218250, 1856, 1952, 2176, 2528, 1392, 1393, 1396, 1439, B_POSITIVE_VSYNC}, B_CMAP8, 1856, 1392, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1856X1392) from Be, Inc. driver + XFree86 */
{ { 288000, 1856, 1984, 2208, 2560, 1392, 1393, 1396, 1500, B_POSITIVE_VSYNC}, B_CMAP8, 1856, 1392, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@75Hz_(1856X1392) from Be, Inc. driver + XFree86 */
/* 4:3 modes; 2.765M pixels */
{ { 234000, 1920, 2048, 2256, 2600, 1440, 1441, 1444, 1500, B_POSITIVE_VSYNC}, B_CMAP8, 1920, 1440, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1920X1440) from Be, Inc. driver + XFree86 */
{ { 297000, 1920, 2064, 2288, 2640, 1440, 1441, 1444, 1500, B_POSITIVE_VSYNC}, B_CMAP8, 1920, 1440, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@75Hz_(1920X1440) from Be, Inc. driver + XFree86 */
/* 4:3 modes; 3.146M pixels */
{ { 266950, 2048, 2200, 2424, 2800, 1536, 1537, 1540, 1589, B_POSITIVE_VSYNC}, B_CMAP8, 2048, 1536, 0, 0, MODE_FLAGS}, /* From XFree86 posting @60Hz + XFree86 */
/* 16:10 panel mode; 400k pixels */
{ { 31300, 800, 848, 928, 1008, 500, 501, 504, 518, T_POSITIVE_SYNC}, B_CMAP8, 800, 500, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(800X500) */
/* 16:10 panel mode; 655.36k pixels */
{ { 52800, 1024, 1072, 1176, 1328, 640, 641, 644, 663, T_POSITIVE_SYNC}, B_CMAP8, 1024, 640, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1024X640) */
/* 16:10 panel-TV mode; 983.04k pixels */
{ { 80135, 1280, 1344, 1480, 1680, 768, 769, 772, 795, T_POSITIVE_SYNC}, B_CMAP8, 1280, 768, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1280X768) */
/* 16:10 panel mode; 1.024M pixels */
{ { 83500, 1280, 1344, 1480, 1680, 800, 801, 804, 828, T_POSITIVE_SYNC}, B_CMAP8, 1280, 800, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1280X800) */
/* 16:10 panel mode; 1.296M pixels */
{ { 106500, 1440, 1520, 1672, 1904, 900, 901, 904, 932, T_POSITIVE_SYNC}, B_CMAP8, 1440, 900, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1440X900) */
/* 16:10 panel mode; 1.764M pixels */
{ { 147100, 1680, 1784, 1968, 2256, 1050, 1051, 1054, 1087, T_POSITIVE_SYNC}, B_CMAP8, 1680, 1050, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1680X1050) */
/* 16:10 panel mode; 2.304M pixels */
{ { 193160, 1920, 2048, 2256, 2592, 1200, 1201, 1204, 1242, T_POSITIVE_SYNC}, B_CMAP8, 1920, 1200, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1920X1200) */
//{ { 160000, 1920, 2010, 2060, 2110, 1200, 1202, 1208, 1235, T_POSITIVE_SYNC}, B_CMAP8, 1920, 1200, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1920X1200) */
/* 16:9 panel mode; 1280x720 (HDTV 1280x720p) */
{ { 74520, 1280, 1368, 1424, 1656, 720, 724, 730, 750, T_POSITIVE_SYNC}, B_CMAP8, 1280, 720, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1280X720) */
/* 16:9 panel mode; 1366x768 (HDTV '1280x720p')
   note: horizontal CRTC timing must be a multiple of 8! (hardware restriction) */
{ { 85500, 1368, 1440, 1576, 1792, 768, 771, 774, 798, T_POSITIVE_SYNC}, B_CMAP8, 1368, 768, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1366X768) */
/* 16:9 panel mode; 1920x1080 (HDTV 1920x1080p) */
{ { 148500, 1920, 2008, 2052, 2200, 1080, 1084, 1089, 1125, T_POSITIVE_SYNC}, B_CMAP8, 1920, 1080, 0, 0, MODE_FLAGS}, /* Vesa_Monitor_@60Hz_(1920X1080) */
};

/*
Check mode is between low and high limits
returns:
        B_OK - found one
        B_BAD_VALUE - mode can be made, but outside limits
        B_ERROR - not possible
*/
/* BOUNDS WARNING:
 * BeOS (tested R5.0.3PE) is failing BWindowScreen.SetFrameBuffer() if PROPOSEMODE
 * returns B_BAD_VALUE. It's called by the OS with target, low and high set to
 * have the same settings for BWindowScreen!
 * Which means we should not return B_BAD_VALUE on anything except for deviations on:
 * display_mode.virtual_width;
 * display_mode.virtual_height;
 * display_mode.timing.h_display;
 * display_mode.timing.v_display;
 */
/* Note:
 * The target mode should be modified to correspond to the mode as it can be made. */
status_t PROPOSE_DISPLAY_MODE(display_mode *target, const display_mode *low, const display_mode *high) 
{
        status_t status = B_OK;
        float pix_clock_found;
        uint8 m,n,p, bpp;
        status_t result;
        uint32 max_vclk, row_bytes, pointer_reservation;
        bool acc_mode;
        double target_refresh = ((double)target->timing.pixel_clock * 1000.0) /
                        (
                                (double)target->timing.h_total * 
                                (double)target->timing.v_total
                        );
        bool
                want_same_width = target->timing.h_display == target->virtual_width,
                want_same_height = target->timing.v_display == target->virtual_height;

        LOG(1, ("PROPOSEMODE: (ENTER) requested virtual_width %d, virtual_height %d\n",
                                                                        target->virtual_width, target->virtual_height));

        /* check colorspace versus requested dualhead mode */
        switch (target->space)
        {
        case B_CMAP8:
        case B_RGB15:
                /* mode will be made 'outside limits' when dualhead was requested */
                if (target->flags & DUALHEAD_BITS)
                {
                        status = B_BAD_VALUE;
                        LOG(4, ("PROPOSEMODE: WARNING: Colorspace can't be done in dualhead mode\n"));
                }
                /* clear dualhead bits if colorspace isn't supported to prevent ProposeMode
                 * from aborting */
                target->flags &= ~(DUALHEAD_BITS | DUALHEAD_CAPABLE);
                break;
        }

        /*find a nearby valid timing from that given*/
        result = gx00_crtc_validate_timing
        (
                &target->timing.h_display, &target->timing.h_sync_start, &target->timing.h_sync_end, &target->timing.h_total,
                &target->timing.v_display, &target->timing.v_sync_start, &target->timing.v_sync_end, &target->timing.v_total
        );
        if (result == B_ERROR)
        {
                LOG(4, ("PROPOSEMODE: could not validate timing, aborted.\n"));
                return result;
        }

        /* validate display vs. virtual */
        if ((target->timing.h_display > target->virtual_width) || want_same_width)
                target->virtual_width = target->timing.h_display;
        if ((target->timing.v_display > target->virtual_height) || want_same_height)
                target->virtual_height = target->timing.v_display;

        /* nail virtual size and 'subsequently' calculate rowbytes */
        result = gx00_general_validate_pic_size (target, &row_bytes, &acc_mode);
        if (result == B_ERROR)
        {
                LOG(4, ("PROPOSEMODE: could not validate virtual picture size, aborted.\n"));
                return result;
        }

        /*check if virtual_width is still within the requested limits*/
        if ((target->virtual_width < low->virtual_width) ||
                (target->virtual_width > high->virtual_width))
        {
                status = B_BAD_VALUE;
                LOG(4, ("PROPOSEMODE: WARNING: virtual_width deviates too much\n"));
        }

        /*check if timing found is within the requested horizontal limits*/
        if ((target->timing.h_display < low->timing.h_display) ||
                (target->timing.h_display > high->timing.h_display) ||
                (target->timing.h_sync_start < low->timing.h_sync_start) ||
                (target->timing.h_sync_start > high->timing.h_sync_start) ||
                (target->timing.h_sync_end < low->timing.h_sync_end) ||
                (target->timing.h_sync_end > high->timing.h_sync_end) ||
                (target->timing.h_total < low->timing.h_total) ||
                (target->timing.h_total > high->timing.h_total))
        {
                /* BWindowScreen workaround: we accept everything except h_display deviations */
                if ((target->timing.h_display < low->timing.h_display) ||
                        (target->timing.h_display > high->timing.h_display))
                {               
                        status = B_BAD_VALUE;
                }
                LOG(4, ("PROPOSEMODE: WARNING: horizontal timing deviates too much\n"));
        }

        /*check if timing found is within the requested vertical limits*/
        if (
                (target->timing.v_display < low->timing.v_display) ||
                (target->timing.v_display > high->timing.v_display) ||
                (target->timing.v_sync_start < low->timing.v_sync_start) ||
                (target->timing.v_sync_start > high->timing.v_sync_start) ||
                (target->timing.v_sync_end < low->timing.v_sync_end) ||
                (target->timing.v_sync_end > high->timing.v_sync_end) ||
                (target->timing.v_total < low->timing.v_total) ||
                (target->timing.v_total > high->timing.v_total)
        )
        {
                /* BWindowScreen workaround: we accept everything except v_display deviations */
                if ((target->timing.v_display < low->timing.v_display) ||
                        (target->timing.v_display > high->timing.v_display))
                {               
                        status = B_BAD_VALUE;
                }
                LOG(4, ("PROPOSEMODE: WARNING: vertical timing deviates too much\n"));
        }

        /* adjust pixelclock for possible timing modifications done above */
        target->timing.pixel_clock = target_refresh * ((double)target->timing.h_total) * ((double)target->timing.v_total) / 1000.0;

        /* Now find the nearest valid pixelclock we actually can setup for the target mode,
         * this also makes sure we don't generate more pixel bandwidth than the device can handle */
        /* calculate settings, but do not actually test anything (that costs too much time!) */
        result = gx00_dac_pix_pll_find(*target,&pix_clock_found,&m,&n,&p,0);
        /* update the target mode */
        target->timing.pixel_clock = (pix_clock_found * 1000);  

        /* note if we fell outside the limits */
        if ((target->timing.pixel_clock < low->timing.pixel_clock) ||
                (target->timing.pixel_clock > high->timing.pixel_clock)
        )
        {
                /* BWindowScreen workaround: we accept deviations <= 1Mhz */
                if ((target->timing.pixel_clock < (low->timing.pixel_clock - 1000)) ||
                        (target->timing.pixel_clock > (high->timing.pixel_clock + 1000)))
                {
                        status = B_BAD_VALUE;
                }
                LOG(4, ("PROPOSEMODE: WARNING: pixelclock deviates too much\n"));
        }

        /* checkout space needed for hardcursor (if any) */
        pointer_reservation = 0;
        /* MIL 1/2 cards have a seperate buffer for the cursorbitmap inside the DAC */
        if ((si->ps.card_type >= G100) && si->settings.hardcursor) pointer_reservation = 1024;
        /* memory requirement for frame buffer */
        if ((row_bytes * target->virtual_height) >
                ((si->ps.memory_size * 1024 * 1024) - pointer_reservation))
        {
                target->virtual_height = 
                        ((si->ps.memory_size * 1024 * 1024) - pointer_reservation) / row_bytes;
        }
        if (target->virtual_height < target->timing.v_display) 
        {
                LOG(4,("PROPOSEMODE: not enough memory for current mode, aborted.\n"));
                return B_ERROR;
        }
        LOG(4,("PROPOSEMODE: validated virtual_width %d, virtual_height %d pixels\n",
                target->virtual_width, target->virtual_height));

        if ((target->virtual_height < low->virtual_height) ||
                (target->virtual_height > high->virtual_height))
        {
                status = B_BAD_VALUE;
                LOG(4, ("PROPOSEMODE: WARNING: virtual_height deviates too much\n"));
        }

        /* setup status flags */ 
        LOG(1, ("PROPOSEMODE: initial modeflags: $%08x\n", target->flags));
        /* preset to singlehead card without TVout, no overlay support and no hardcursor.
         * also advice system that app_server and acc engine may touch the framebuffer
         * simultaneously (fixed). */
        target->flags &=
                ~(DUALHEAD_CAPABLE | TV_CAPABLE | B_SUPPORTS_OVERLAYS | B_HARDWARE_CURSOR | B_IO_FB_NA);
        /* we always allow parallel access (fixed), the DAC is always in 'enhanced'
         * mode (fixed), and all modes support DPMS (fixed);
         * We support scrolling and panning in every mode, so we 'send a signal' to
         * BWindowScreen.CanControlFrameBuffer() by setting B_SCROLL.  */
        /* BTW: B_PARALLEL_ACCESS in combination with a hardcursor enables
         * BDirectWindow windowed modes. */
        target->flags |= (B_PARALLEL_ACCESS | B_8_BIT_DAC | B_DPMS | B_SCROLL);

        /* determine the 'would be' max. pixelclock for the second DAC for the current videomode if dualhead were activated */
        switch (target->space)
        {
                case B_CMAP8:
                        max_vclk = si->ps.max_dac2_clock_8;
                        bpp = 1;
                        break;
                case B_RGB15_LITTLE:
                case B_RGB16_LITTLE:
                        max_vclk = si->ps.max_dac2_clock_16;
                        bpp = 2;
                        break;
                case B_RGB24_LITTLE:
                        max_vclk = si->ps.max_dac2_clock_24;
                        bpp = 3;
                        break;
                case B_RGB32_LITTLE:
                        max_vclk = si->ps.max_dac2_clock_32dh;
                        bpp = 4;
                        break;
                default:
                        /* use fail-safe value */
                        max_vclk = si->ps.max_dac2_clock_32dh;
                        bpp = 4;
                        break;
        }

        /* set DUALHEAD_CAPABLE if suitable */
        //fixme: update for independant secondary head use! (reserve fixed memory then)
        if (si->ps.secondary_head &&
                ((target->space == B_RGB16_LITTLE) || (target->space == B_RGB32_LITTLE)) &&
                (target->timing.pixel_clock <= (max_vclk * 1000)))
        {
                /* extra line for G400 MAVEN vblank design fault workaround needed! */
                uint16 vblank_fix = 0;
                if (si->ps.card_type <= G400MAX) vblank_fix = 1;

                switch (target->flags & DUALHEAD_BITS)
                {
                case DUALHEAD_ON:
                case DUALHEAD_SWITCH:
                        if ((((si->ps.memory_size * 1024 * 1024) - pointer_reservation) >=
                                        (row_bytes * (target->virtual_height + vblank_fix))) &&
                                ((uint16)(row_bytes / bpp) >= (target->timing.h_display * 2)))
                        {
                                target->flags |= DUALHEAD_CAPABLE;
                        }
                        break;
                case DUALHEAD_CLONE:
                        if (((si->ps.memory_size * 1024 * 1024) - pointer_reservation) >=
                                        (row_bytes * (target->virtual_height + vblank_fix)))
                        {
                                target->flags |= DUALHEAD_CAPABLE;
                        }
                        break;
                case DUALHEAD_OFF:
                        if (((si->ps.memory_size * 1024 * 1024) - pointer_reservation) >=
                                        (row_bytes * (target->virtual_height + vblank_fix) * 2))
                        {
                                target->flags |= DUALHEAD_CAPABLE;
                        }
                        break;
                }
        }

        /* if not dualhead capable card clear dualhead flags */
        if (!(target->flags & DUALHEAD_CAPABLE))
        {
                target->flags &= ~DUALHEAD_BITS;
        }

        /* set TV_CAPABLE if suitable: pixelclock is not important (defined by TVstandard) */
        switch (si->ps.card_type)
        {
        case G100:
        case G200:
                /* confirmed most 8-bit modes to be troublesome for TVout (data fetch errors). */
                if (si->ps.tvout &&
                        ((target->space == B_RGB16_LITTLE) || (target->space == B_RGB32_LITTLE)) &&
                        (target->timing.h_display <= 1024) &&
                        (target->timing.v_display <= 768))
                {
                        target->flags |= TV_CAPABLE;
                }
                break;
        case G400:
        case G400MAX:
                if (si->ps.tvout &&
                        ((target->space == B_RGB16_LITTLE) || (target->space == B_RGB32_LITTLE)) &&
                        (target->timing.h_display <= 1024) &&
                        (target->timing.v_display <= 768))
                {
                        target->flags |= TV_CAPABLE;
                }
                break;
        case G450:
        case G550:
                /* G450/G550 can only do secondary TVout in Video modes (no Desktop modes!) */
                if ((target->flags & DUALHEAD_CAPABLE) && (target->flags & TV_VIDEO))
                {
                        if (si->ps.tvout &&
                                (target->timing.h_display <= 1024) &&   /* Hscaling option exists */
                                (target->timing.v_display <= 576))              /* Vscaling option lacks */
                        {
                                target->flags |= TV_CAPABLE;
                        }
                }
                break;
        default:
                break;
        }

        /* TVout can only be done if the interface cable is connected on dualhead cards */
        if (si->ps.secondary_head && (i2c_sec_tv_adapter() != B_OK))
        {
                target->flags &= ~TV_CAPABLE;
                LOG(1, ("PROPOSEMODE: blocking TVout: no TVout cable connected!\n"));
        }

        /* if not TVout capable card and mode clear TVout flags */
        if (!(target->flags & TV_CAPABLE))
        {
                target->flags &= ~TV_BITS;
        }

        /* the matrox driver can only do secondary TVout on dualhead cards */
        if ((target->flags & TV_BITS) && !si->ps.secondary_head)
        {
                target->flags |= TV_PRIMARY;
        }
        else
        {
                target->flags &= ~TV_PRIMARY;
        }

        /* set HARDWARE_CURSOR mode if suitable */
        if (si->settings.hardcursor)
                target->flags |= B_HARDWARE_CURSOR;

        /* set SUPPORTS_OVERLAYS if suitable */
        if (si->ps.card_type >= G200)
                target->flags |= B_SUPPORTS_OVERLAYS;

        LOG(1, ("PROPOSEMODE: validated modeflags: $%08x\n", target->flags));

        /* overrule timing command flags to be (fixed) blank_pedestal = 0.0IRE,
         * progressive scan (fixed), and setup sync_on_green flag according to
         * mga.settings options file */
        target->timing.flags &= ~(B_BLANK_PEDESTAL | B_TIMING_INTERLACED | B_SYNC_ON_GREEN);
        if (si->settings.greensync)
                target->timing.flags |= B_SYNC_ON_GREEN;
        /* The HSYNC and VSYNC command flags are actually executed by the driver. */

        if (status == B_OK)     LOG(4, ("PROPOSEMODE: completed successfully.\n"));
        else LOG(4, ("PROPOSEMODE: mode can be made, but outside given limits.\n"));
        return status;
}

/* Return the number of modes this device will return from GET_MODE_LIST().  
        This is precalculated in create_mode_list (called from InitAccelerant stuff)
*/
uint32 ACCELERANT_MODE_COUNT(void)
{
        LOG(1, ("ACCELERANT_MODE_COUNT: the modelist contains %d modes\n",si->mode_count));

        return si->mode_count;
}

/* Copy the list of guaranteed supported video modes to the location provided.*/
status_t GET_MODE_LIST(display_mode *dm)
{
        LOG(1, ("GET_MODE_LIST: exporting the modelist created before.\n"));

        memcpy(dm, my_mode_list, si->mode_count * sizeof(display_mode));
        return B_OK;
}

/* Create a list of display_modes to pass back to the caller.*/
status_t create_mode_list(void) {
        size_t max_size;
        uint32
                i, j,
                pix_clk_range;
        const display_mode
                *src;
        display_mode
                *dst,
                low,
                high;

        color_space spaces[4] = {B_RGB32_LITTLE,B_RGB16_LITTLE,B_RGB15_LITTLE,B_CMAP8};

        /* figure out how big the list could be, and adjust up to nearest multiple of B_PAGE_SIZE*/
        max_size = (((MODE_COUNT * 4) * sizeof(display_mode)) + (B_PAGE_SIZE-1)) & ~(B_PAGE_SIZE-1);
        /* create an area to hold the info */
        si->mode_area = my_mode_list_area =
                create_area("MGA accelerant mode info", (void **)&my_mode_list, B_ANY_ADDRESS, max_size,
                        B_NO_LOCK, B_READ_AREA | B_WRITE_AREA | B_CLONEABLE_AREA);
        if (my_mode_list_area < B_OK) return my_mode_list_area;

        /* walk through our predefined list and see which modes fit this device */
        src = mode_list;
        dst = my_mode_list;
        si->mode_count = 0;
        for (i = 0; i < MODE_COUNT; i++) {
                /* set ranges for acceptable values */
                low = high = *src;
                /* range is 6.25% of default clock: arbitrarily picked */ 
                pix_clk_range = low.timing.pixel_clock >> 5;
                low.timing.pixel_clock -= pix_clk_range;
                high.timing.pixel_clock += pix_clk_range;
                /* 'some cards need wider virtual widths for certain modes':
                 * Not true. They might need a wider pitch, but this is _not_ reflected in
                 * virtual_width, but in fbc.bytes_per_row. */
                //So disable next line: 
                //high.virtual_width = 4096;
                /* do it once for each depth we want to support */
                for (j = 0; j < (sizeof(spaces) / sizeof(color_space)); j++) 
                {
                        /* set target values */
                        *dst = *src;
                        /* poke the specific space */
                        dst->space = low.space = high.space = spaces[j];
                        /* ask for a compatible mode */
                        /* We have to check for B_OK, because otherwise the pix_clk_range
                         * won't be taken into account!! */
                        //So don't do this: 
                        //if (PROPOSE_DISPLAY_MODE(dst, &low, &high) != B_ERROR) {
                        //Instead, do this:
                        if (PROPOSE_DISPLAY_MODE(dst, &low, &high) == B_OK) {
                                /* count it, and move on to next mode */
                                dst++;
                                si->mode_count++;
                        }
                }
                /* advance to next mode */
                src++;
        }
        
        return B_OK;
}