root/src/add-ons/accelerants/skeleton/GetModeInfo.c
/*
        Copyright 1999, Be Incorporated.   All Rights Reserved.
        This file may be used under the terms of the Be Sample Code License.

        Other authors:
        Mark Watson
        Rudolf Cornelissen 9/2002-5/2003
*/

#define MODULE_BIT 0x02000000

#include "acc_std.h"

/*
        Return the current display mode.  The only time you might return an
        error is if a mode hasn't been set. Or if the system hands you a NULL pointer.
*/
status_t GET_DISPLAY_MODE(display_mode *current_mode)
{
        /* check for NULL pointer */
        if (current_mode == NULL) return B_ERROR;

        *current_mode = si->dm;
        return B_OK;
}

/* Return the frame buffer configuration information. */
status_t GET_FRAME_BUFFER_CONFIG(frame_buffer_config *afb)
{
        /* check for NULL pointer */
        if (afb == NULL) return B_ERROR;

        *afb = si->fbc;
        return B_OK;
}

/* Return the maximum and minium pixelclock limits for the specified mode. */
/* NOTE:
 * Due to BeOS constraints output for all heads will be limited to the head with
 * the least capabilities. */
status_t GET_PIXEL_CLOCK_LIMITS(display_mode *dm, uint32 *low, uint32 *high) 
{
        uint32 max_pclk = 0;
        uint32 min_pclk = 0;

        /* check for NULL pointers */
        if ((dm == NULL) || (low == NULL) || (high == NULL)) return B_ERROR;

        /* specify requested info */
        if (dm->flags & DUALHEAD_BITS)
        {
                /* dualhead mode */
                /* find min. value */
                switch (si->ps.card_type)
                {
                        default:
                                *low = ((si->ps.min_video_vco * 1000) / 16);
                                break;
                }
                /* find max. value:
                 * using decondary DAC specs because they could be narrower (twinview) */
                switch (dm->space)
                {
                        case B_CMAP8:
                                max_pclk = si->ps.max_dac2_clock_8;
                                break;
                        case B_RGB15_LITTLE:
                        case B_RGB16_LITTLE:
                                max_pclk = si->ps.max_dac2_clock_16;
                                break;
                        case B_RGB24_LITTLE:
                                max_pclk = si->ps.max_dac2_clock_24;
                                break;
                        case B_RGB32_LITTLE:
                                /* specially noted because of RAM speed constraints! */
                                max_pclk = si->ps.max_dac2_clock_32dh;
                                break;
                        default:
                                /* use fail-safe value */
                                max_pclk = si->ps.max_dac2_clock_32dh;
                                break;
                }
                /* return values in kHz */
                *high = max_pclk * 1000;
        }
        else
        {
                /* singlehead mode */
                /* find min. value */
                switch (si->ps.card_type)
                {
                        default:
                                *low = ((si->ps.min_pixel_vco * 1000) / 16);
                                break;
                }
                /* find max. value: depends on which head is used as primary head */
                if (!si->ps.crtc2_prim)
                {
                        switch (dm->space)
                        {
                                case B_CMAP8:
                                        max_pclk = si->ps.max_dac1_clock_8;
                                        break;
                                case B_RGB15_LITTLE:
                                case B_RGB16_LITTLE:
                                        max_pclk = si->ps.max_dac1_clock_16;
                                        break;
                                case B_RGB24_LITTLE:
                                        max_pclk = si->ps.max_dac1_clock_24;
                                        break;
                                case B_RGB32_LITTLE:
                                        max_pclk = si->ps.max_dac1_clock_32;
                                        break;
                                default:
                                        /* use fail-safe value */
                                        max_pclk = si->ps.max_dac1_clock_32;
                                        break;
                        }
                }
                else
                {
                        switch (dm->space)
                        {
                                case B_CMAP8:
                                        max_pclk = si->ps.max_dac2_clock_8;
                                        break;
                                case B_RGB15_LITTLE:
                                case B_RGB16_LITTLE:
                                        max_pclk = si->ps.max_dac2_clock_16;
                                        break;
                                case B_RGB24_LITTLE:
                                        max_pclk = si->ps.max_dac2_clock_24;
                                        break;
                                case B_RGB32_LITTLE:
                                        max_pclk = si->ps.max_dac2_clock_32;
                                        break;
                                default:
                                        /* use fail-safe value */
                                        max_pclk = si->ps.max_dac2_clock_32;
                                        break;
                        }
                }
                /* return values in kHz */
                *high = max_pclk * 1000;
        }

        /* clamp lower limit to 48Hz vertical refresh for now.
         * Apparantly the BeOS screenprefs app does limit the upper refreshrate to 90Hz,
         * while it does not limit the lower refreshrate. */
        min_pclk = ((uint32)dm->timing.h_total * (uint32)dm->timing.v_total * 48) / 1000;
        if (min_pclk > *low) *low = min_pclk;

        return B_OK;
}

/* Return the semaphore id that will be used to signal a vertical sync occured.  */
sem_id ACCELERANT_RETRACE_SEMAPHORE(void)
{
//      return si->vblank;
return B_ERROR;
}