/* Author:
   Rudolf Cornelissen 6/2004-9/2004
*/

#define MODULE_BIT 0x00000100

#include <unistd.h>
#include "std.h"


status_t
eng_agp_setup(void)
{
        eng_nth_agp_info nai;
        eng_cmd_agp nca;
        uint8 index;
        agp_info eng_ai;
        bool agp = false;
        eng_ai.interface.status = 0;

        /* set the magic number so the via kerneldriver knows we're for real */
        nca.magic = nai.magic = VIA_PRIVATE_DATA_MAGIC;

        /* contact driver and get a pointer to the registers and shared data */
        for (index = 0; index < 8; index++) {
                /* get nth AGP device info */
                nai.index = index;
                ioctl(fd, ENG_GET_NTH_AGP_INFO, &nai, sizeof(nai));

                /* abort if no agp busmanager found */
                if (!nai.agp_bus) {
                        LOG(4,("AGP: no AGP busmanager found.\n"));
                        /* don't touch AGP command register, we don't know what has been setup:
                         * touching it anyway might 'hang' the graphics card! */

                        return B_ERROR;
                }

                /* exit if we didn't get device info for this index */
                if (!nai.exist) {
                        if (index != 0)
                                LOG(4,("AGP: end of AGP capable devices list.\n"));
                        else
                                LOG(4,("AGP: no AGP capable devices found.\n"));
                        break;
                }

                LOG(4,("AGP: AGP capable device #%d:\n", (index + 1)));

                /* see if we are this one */
                if (nai.agpi.device_id == si->device_id
                        && nai.agpi.vendor_id == si->vendor_id
                        && nai.agpi.bus == si->bus
                        && nai.agpi.device == si->device
                        && nai.agpi.function == si->function) {
                        LOG(4,("AGP: (this is the device this accelerant controls)\n"));
                        agp = true;
                        /* remember our info */
                        eng_ai = nai.agpi;
                }
        }

        /* if our card is not an AGP type, abort here */
        /* Note:
         * We have to iterate through the capability list as specified in the PCI spec
         * one way or the other, otherwise we cannot distinquish between PCI and
         * AGP type cards as PCI cards still might have AGP registers that pretend to
         * support AGP.
         * We rely on the AGP busmanager to iterate trough this list for us. */
        if (!agp) {
                LOG(4,("AGP: the graphicscard this accelerant controls is PCI type.\n"));

                /* make sure card is set for PCI access */
//              CFGW(AGPCMD, 0x00000000);

                return B_ERROR;
        }

        if (si->settings.force_pci) {
                /* set PCI mode if specified by user in skel.settings */
                LOG(4,("AGP: forcing PCI mode (specified in via.settings)\n"));

                /* let the AGP busmanager setup PCI mode.
                 * (the AGP speed scheme is of no consequence now) */
                nca.cmd = 0x00000000;
                ioctl(fd, ENG_ENABLE_AGP, &nca, sizeof(nca));
        } else {
                /* activate AGP mode */
                LOG(4,("AGP: activating AGP mode...\n"));

                /* let the AGP busmanager worry about what mode to set.. */
                nca.cmd = 0xfffffff7;
                /* ..but we do need to select the right speed scheme fetched from our card */
                if (eng_ai.interface.status & AGP_3_MODE)
                        nca.cmd |= AGP_3_MODE;
                ioctl(fd, ENG_ENABLE_AGP, &nca, sizeof(nca));
        }

        /* extra check */
//      LOG(4,("AGP: graphics card AGPCMD register readback $%08x\n", CFGR(AGPCMD)));
        return B_OK;
}