path: root/src/glide_driver.c

/*
 * XFree86 driver for Glide(tm). (Mainly for Voodoo 1 and 2 cards)
 *
 * Since Voodoo 1 and Voodoo 2 cards are very, very NOT made for running a
 * 2D windowing system, this driver is a little special. Basically, we have
 * a virtual framebuffer in RAM (the Shadow Framebuffer) and we copy selected
 * regions of this to the voodoo card at appropriate times. We get no hardware
 * acceleration help (there isn't any for 2D on these cards), but since the
 * framebuffer is in cached RAM, we get a useable display anyway. Also, we
 * don't have any interaction with any hardware since Glide is the layer
 * beneath the driver.
 *
 * Author:
 *   Henrik Harmsen (hch@cd.chalmers.se or Henrik.Harmsen@erv.ericsson.se)
 *
 * HISTORY
 * 1999-04-05
 * - First release for 3.9Pi
 *
 * 1999-04-17
 * - Soft link to libglide2x.so instead of addition to ModulePath
 * - Changed "EXTERN_MODULE" to EXTERN_MODULE
 * - Uses the "GlideDevice" option instead of the "BusID" line to select
 *   which voodoo board to use.
 * - Manpage updates
 *
 * 1999-06-25
 * - Modify glideSetup to not register the driver when libglide2x.so
 *   cannot be loaded, and to return appropriate error codes when it fails.
 * - Prevent GLIDEFreeScreen() from crashing if called early.
 *
 * 1999-08-22
 * - Minor fixes.
 *
 * 1999-11-22
 * - Minor change in GLIDE_FIND_FUNC by Loïc Grenié, grenie@math.jussieu.fr.
 *
 * TODO
 * - Support for adjusting gamma correction.
 * - Support for setting gamma individually for R,G,B when Glide 3 arrives
 *   for Linux.  This will allow me to get rid of that sick green tint my
 *   voodoo2 board produces...
 * - Support static loading.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "colormapst.h"
#include "xf86.h"
#include "xf86_OSproc.h"
#include "mipointer.h"
#include "micmap.h"
#include "globals.h"
#ifdef HAVE_XEXTPROTO_71
#include <X11/extensions/dpmsconst.h>
#else
#define DPMS_SERVER
#include <X11/extensions/dpms.h>
#endif

#include "fb.h"
#include "xf86cmap.h"
#include "shadowfb.h"

#include "compat-api.h"

#include <glide.h>

/* glide3x does not define this alias anymore, so let's do it ourselves. */
#ifndef GR_ZDEPTHVALUE_FARTHEST
#define GR_ZDEPTHVALUE_FARTHEST 0
#endif

#define TRUE 1
#define FALSE 0

typedef signed char s8;
typedef unsigned char u8;
typedef signed short int s16;
typedef unsigned short int u16;
typedef signed long int s32;
typedef unsigned long int u32;

/* Card-specific driver information */

#define GLIDEPTR(p) ((GLIDEPtr)((p)->driverPrivate))

typedef struct {
    u8 *ShadowPtr;
    u32 ShadowPitch;
    u32 SST_Index;
    CloseScreenProcPtr CloseScreen;
    Bool Blanked;
    u32 grRefreshRate;
    u32 grResolution;
    Bool OnAtExit;
    Bool GlideInitiated;
    EntityInfoPtr pEnt;
    OptionInfoPtr Options;
} GLIDERec, *GLIDEPtr;

static const OptionInfoRec *GLIDEAvailableOptions(int chipid, int busid);
static void GLIDEIdentify(int flags);
static Bool GLIDEProbe(DriverPtr drv, int flags);
static Bool GLIDEPreInit(ScrnInfoPtr pScrn, int flags);
static Bool GLIDEScreenInit(SCREEN_INIT_ARGS_DECL);
static Bool GLIDEEnterVT(VT_FUNC_ARGS_DECL);
static void GLIDELeaveVT(VT_FUNC_ARGS_DECL);
static Bool GLIDECloseScreen(CLOSE_SCREEN_ARGS_DECL);
static Bool GLIDESaveScreen(ScreenPtr pScreen, int mode);
static void GLIDEFreeScreen(FREE_SCREEN_ARGS_DECL);
static void GLIDERefreshArea(ScrnInfoPtr pScrn, int num, BoxPtr pbox);
static Bool GLIDEModeInit(ScrnInfoPtr pScrn, DisplayModePtr mode);
static void GLIDERestore(ScrnInfoPtr pScrn, Bool Closing);
static void GLIDERefreshAll(ScrnInfoPtr pScrn);

static void GLIDEDisplayPowerManagementSet(ScrnInfoPtr pScrn,
                                           int PowerManagementMode,
                                           int flags);

#define GLIDE_VERSION 4000
#define GLIDE_NAME "GLIDE"
#define GLIDE_DRIVER_NAME "glide"
#define GLIDE_MAJOR_VERSION PACKAGE_VERSION_MAJOR
#define GLIDE_MINOR_VERSION PACKAGE_VERSION_MINOR
#define GLIDE_PATCHLEVEL PACKAGE_VERSION_PATCHLEVEL

/*
 * This contains the functions needed by the server after loading the
 * driver module.  It must be supplied, and gets added the driver list by
 * the Module Setup funtion in the dynamic case.  In the static case a
 * reference to this is compiled in, and this requires that the name of
 * this DriverRec be an upper-case version of the driver name.
 */
_X_EXPORT DriverRec GLIDE = {
    GLIDE_VERSION,
    GLIDE_DRIVER_NAME,
    GLIDEIdentify,
    GLIDEProbe,
    GLIDEAvailableOptions,
    NULL,
    0
};

typedef enum {
    OPTION_ON_AT_EXIT,
    OPTION_GLIDEDEVICE
} GLIDEOpts;

static const OptionInfoRec GLIDEOptions[] = {
    { OPTION_ON_AT_EXIT, "OnAtExit", OPTV_BOOLEAN, { 0 }, FALSE },
    { OPTION_GLIDEDEVICE, "GlideDevice", OPTV_INTEGER, { 0 }, FALSE },
    { -1, NULL, OPTV_NONE, { 0 }, FALSE }
};

/* Supported chipsets */
static SymTabRec GLIDEChipsets[] = {
    { 0, "Voodoo" },
    { -1, NULL }
};

#ifdef XFree86LOADER

static MODULESETUPPROTO(glideSetup);

static XF86ModuleVersionInfo glideVersRec = {
    "glide",
    MODULEVENDORSTRING,
    MODINFOSTRING1,
    MODINFOSTRING2,
    XORG_VERSION_CURRENT,
    GLIDE_MAJOR_VERSION, GLIDE_MINOR_VERSION, GLIDE_PATCHLEVEL,
    ABI_CLASS_VIDEODRV,         /* This is a video driver */
    ABI_VIDEODRV_VERSION,
    MOD_CLASS_VIDEODRV,
    { 0, 0, 0, 0 }
};

_X_EXPORT XF86ModuleData glideModuleData = {
    &glideVersRec,
    glideSetup,
    NULL
};

static pointer
glideSetup(pointer module, pointer opts, int *errmaj, int *errmin)
{
    static Bool setupDone = FALSE;
    int errmaj2 = 0, errmin2 = 0;

    if (!setupDone) {
        setupDone = TRUE;
        /* This module should be loaded only once */
        *errmaj = LDR_ONCEONLY;
        xf86AddDriver(&GLIDE, module, 0);

        /*
         * The return value must be non-NULL on success even though there
         * is no TearDownProc.
         */
        return (pointer)1;
    }
    else {
        if (errmaj)
            *errmaj = LDR_ONCEONLY;
        return NULL;
    }
}
#endif                          /* XFree86LOADER */

static Bool
GLIDEGetRec(ScrnInfoPtr pScrn)
{
    /*
     * Allocate an GLIDERec, and hook it into pScrn->driverPrivate.
     * pScrn->driverPrivate is initialised to NULL, so we can check if
     * the allocation has already been done.
     */
    if (pScrn->driverPrivate != NULL)
        return TRUE;

    pScrn->driverPrivate = xnfcalloc(sizeof(GLIDERec), 1);

    /* Initialize it */
    /* No init here yet */

    return TRUE;
}

static void
GLIDEFreeRec(ScrnInfoPtr pScrn)
{
    if (pScrn->driverPrivate == NULL)
        return;
    free(pScrn->driverPrivate);
    pScrn->driverPrivate = NULL;
}

static const OptionInfoRec *
GLIDEAvailableOptions(int chipid, int busid)
{
    return GLIDEOptions;
}

/* Mandatory */
static void
GLIDEIdentify(int flags)
{
    xf86PrintChipsets(GLIDE_NAME, "driver for Glide devices (Voodoo cards)",
                      GLIDEChipsets);
}

#if defined(GLIDE3)
static int
glide_get_num_boards(void)
{
    FxI32 num_sst;
    int ret;

    ret = grGet(GR_NUM_BOARDS, sizeof(num_sst), &num_sst);
    if (!ret) {
        xf86Msg(X_ERROR,
                "GLIDEProbe(): Error calling grGet(GR_NUM_BOARDS)!\n");
        return -1;
    }

    return num_sst;
}
#else
static int
glide_get_num_boards(void)
{
    GrHwConfiguration hw;
    int ret;

    ret = grSstQueryBoards(&hw);
    if (!ret) {
        xf86Msg(X_ERROR, "GLIDEProbe(): Error calling grSstQueryBoards!\n");
        return -1;
    }

    return hw.num_sst;
}
#endif

/* Mandatory */
static Bool
GLIDEProbe(DriverPtr drv, int flags)
{
    int i, num_sst, sst;
    GDevPtr *devList;
    GDevPtr dev = NULL;
    int numdevList;
    Bool foundScreen = FALSE;
    ScrnInfoPtr pScrn;
    int GlideDevice;

    numdevList = xf86MatchDevice(GLIDE_DRIVER_NAME, &devList);
    if (numdevList <= 0)
        return FALSE;

    num_sst = glide_get_num_boards();
    if (num_sst < 0)
        goto cleanup;

    /* num_sst: number of Glide boards available */
    if (num_sst > 0 && (flags & PROBE_DETECT)) {
        /* XXX Need to call xf886AddDeviceToConfigure() here */
        return TRUE;
    }

    for (sst = 0; sst < num_sst; sst++) {
        for (i = 0; i < numdevList; i++) {
            dev = devList[i];
            GlideDevice = xf86SetIntOption(dev->options, "GlideDevice", 0);
            if (GlideDevice == sst) {
                int entityIndex;

                /* Match */
                entityIndex = xf86ClaimNoSlot(drv, 0, dev, TRUE);
                pScrn = NULL;

                /* Allocate a ScrnInfoRec and claim the slot */
                pScrn = xf86AllocateScreen(drv, 0);
                if (pScrn) {
                    GLIDEPtr pGlide;

                    xf86AddEntityToScreen(pScrn, entityIndex);

                    /* I'm not going to "claim" the glide device since no
                     * other driver than this can drive it */
                    /* (A glide device is not a PCI device) */
                    /* XXX Need to see how this fits in with the new RAC */

                    /* Fill in what we can of the ScrnInfoRec */
                    pScrn->driverVersion = GLIDE_VERSION;
                    pScrn->driverName = GLIDE_DRIVER_NAME;
                    pScrn->name = GLIDE_NAME;
                    pScrn->Probe = GLIDEProbe;
                    pScrn->PreInit = GLIDEPreInit;
                    pScrn->ScreenInit = GLIDEScreenInit;
                    pScrn->EnterVT = GLIDEEnterVT;
                    pScrn->LeaveVT = GLIDELeaveVT;
                    pScrn->FreeScreen = GLIDEFreeScreen;

                    /* Allocate the GLIDERec driverPrivate */
                    if (!GLIDEGetRec(pScrn))
                        break;

                    pGlide = GLIDEPTR(pScrn);
                    pGlide->SST_Index = sst;

                    /*
                     * XXX This is a hack because don't have the PCI info.
                     * Set it as an ISA entity with no resources.
                     */
                    foundScreen = TRUE;
                }
                break;
            }
        }
    }

cleanup:
    free(devList);
    return foundScreen;
}

/* Mandatory */
static Bool
GLIDEPreInit(ScrnInfoPtr pScrn, int flags)
{
    GLIDEPtr pGlide;
    MessageType from;
    int ret;
    ClockRangePtr clockRanges;

    if (flags & PROBE_DETECT)
        return FALSE;

    /* Check the number of entities, and fail if it isn't one. */
    if (pScrn->numEntities != 1)
        return FALSE;

    /* Set pScrn->monitor */
    pScrn->monitor = pScrn->confScreen->monitor;

    if (!xf86SetDepthBpp(pScrn, 16, 0, 0, Support32bppFb))
        return FALSE;

    /* Check that the returned depth is one we support */
    switch (pScrn->depth) {
    case 16:
    case 24:
        /* OK */
        break;
    default:
        xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
                   "Given depth (%d) is not supported by this driver\n",
                   pScrn->depth);
        return FALSE;
    }
    xf86PrintDepthBpp(pScrn);

    /*
     * This must happen after pScrn->display has been set because
     * xf86SetWeight references it.
     */
    if (pScrn->depth > 8) {
        /* The defaults are OK for us */
        rgb zeros = { 0, 0, 0 };

        if (!xf86SetWeight(pScrn, zeros, zeros))
            return FALSE;

        /* XXX check that weight returned is supported */
    }

    /* Set the default visual. */
    if (!xf86SetDefaultVisual(pScrn, -1))
        return FALSE;

    /* We don't support DirectColor at > 8bpp */
    if (pScrn->depth > 8 && pScrn->defaultVisual != TrueColor) {
        xf86DrvMsg(pScrn->scrnIndex, X_ERROR, "Given default visual"
                   " (%s) is not supported at depth %d\n",
                   xf86GetVisualName(pScrn->defaultVisual), pScrn->depth);
        return FALSE;
    }

    /* Set default gamma */
    {
        Gamma zeros = { 0.0, 0.0, 0.0 };

        if (!xf86SetGamma(pScrn, zeros))
            return FALSE;
    }

    /* We use a programmable clock */
    pScrn->progClock = TRUE;

    pGlide = GLIDEPTR(pScrn);

    /* Get the entity */
    pGlide->pEnt = xf86GetEntityInfo(pScrn->entityList[0]);

    /* Collect all of the relevant option flags (fill in pScrn->options) */
    xf86CollectOptions(pScrn, NULL);

    /* Process the options */
    pGlide->Options = malloc(sizeof(GLIDEOptions));
    if (pGlide->Options == NULL)
        return FALSE;
    memcpy(pGlide->Options, GLIDEOptions, sizeof(GLIDEOptions));
    xf86ProcessOptions(pScrn->scrnIndex, pScrn->options, pGlide->Options);

    pGlide->OnAtExit = FALSE;
    from = X_DEFAULT;
    if (xf86GetOptValBool(pGlide->Options, OPTION_ON_AT_EXIT,
                          &(pGlide->OnAtExit)))
        from = X_CONFIG;

    xf86DrvMsg(pScrn->scrnIndex, from,
               "Voodoo card will be %s when exiting server.\n",
               pGlide->OnAtExit ? "ON" : "OFF");

    /*
     * If the user has specified the amount of memory in the XF86Config
     * file, we respect that setting.
     */
    if (pGlide->pEnt->device->videoRam != 0) {
        pScrn->videoRam = pGlide->pEnt->device->videoRam;
        from = X_CONFIG;
    }
    else {
        /* It's just virtual framebuffer anyway so let's say we have an
         * 8MB sized framebuffer. */
        pScrn->videoRam = 8192;
        from = X_PROBED;
    }
#if 0
    xf86DrvMsg(pScrn->scrnIndex, from, "Virtual video RAM: %d kB\n",
               pScrn->videoRam);
#endif

    /* Set up clock ranges so that the xf86ValidateModes() function will not
     * fail a mode because of the clock requirement (because we don't use the
     * clock value anyway) */
    clockRanges = xnfcalloc(sizeof(ClockRange), 1);
    clockRanges->next = NULL;
    clockRanges->minClock = 10000;
    clockRanges->maxClock = 300000;
    clockRanges->clockIndex = -1;       /* programmable */
    clockRanges->interlaceAllowed = TRUE;
    clockRanges->doubleScanAllowed = TRUE;

    /* Select valid modes from those available */
    ret = xf86ValidateModes(pScrn, pScrn->monitor->Modes,
                            pScrn->display->modes, clockRanges,
                            NULL, 256, 2048,
                            pScrn->bitsPerPixel, 128, 2048,
                            pScrn->display->virtualX,
                            pScrn->display->virtualY,
                            pScrn->videoRam * 1024, LOOKUP_BEST_REFRESH);
    if (ret == -1) {
        GLIDEFreeRec(pScrn);
        return FALSE;
    }

    /* Prune the modes marked as invalid */
    xf86PruneDriverModes(pScrn);

    /* If no valid modes, return */
    if (ret == 0 || pScrn->modes == NULL) {
        xf86DrvMsg(pScrn->scrnIndex, X_ERROR, "No valid modes found\n");
        GLIDEFreeRec(pScrn);
        return FALSE;
    }

    /* Set the current mode to the first in the list */
    pScrn->currentMode = pScrn->modes;

    /* Do some checking, we will not support a virtual framebuffer larger than
     * the visible screen. */
    if (pScrn->currentMode->HDisplay != pScrn->virtualX ||
        pScrn->currentMode->VDisplay != pScrn->virtualY ||
        pScrn->displayWidth != pScrn->virtualX) {
        xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
                   "Virtual size doesn't equal display size. Forcing virtual "
                   "size to equal display size.\n");
        xf86DrvMsg(pScrn->scrnIndex, X_WARNING,
                   "(Virtual size: %dx%d, Display size: %dx%d)\n",
                   pScrn->virtualX, pScrn->virtualY,
                   pScrn->currentMode->HDisplay,
                   pScrn->currentMode->VDisplay);
        /* I'm not entirely sure this is "legal" but I hope so. */
        pScrn->virtualX = pScrn->currentMode->HDisplay;
        pScrn->virtualY = pScrn->currentMode->VDisplay;
        pScrn->displayWidth = pScrn->virtualX;
    }

    /* TODO: Note: If I return FALSE right here, the server will not restore
     * the console correctly, forcing a reboot. Must find that. (valid for
     * 3.9Pi) */

    /* Print the list of modes being used */
    xf86PrintModes(pScrn);

    /* Set display resolution */
    xf86SetDpi(pScrn, 0, 0);

    /* Load fb */
    if (xf86LoadSubModule(pScrn, "fb") == NULL) {
        GLIDEFreeRec(pScrn);
        return FALSE;
    }

    /* Load the shadow framebuffer */
    if (!xf86LoadSubModule(pScrn, "shadowfb")) {
        GLIDEFreeRec(pScrn);
        return FALSE;
    }

    return TRUE;
}

/*
 * This gets called at the start of each server generation
 */
/* Mandatory */
static Bool
GLIDEScreenInit(SCREEN_INIT_ARGS_DECL)
{
    ScrnInfoPtr pScrn;
    GLIDEPtr pGlide;
    int ret;
    VisualPtr visual;

    /*
     * First get the ScrnInfoRec
     */
    pScrn = xf86ScreenToScrn(pScreen);

    pGlide = GLIDEPTR(pScrn);

    if (!GLIDEModeInit(pScrn, pScrn->currentMode))
        return FALSE;

    /*
     * The next step is to setup the screen's visuals, and initialise the
     * framebuffer code.  In cases where the framebuffer's default
     * choices for things like visual layouts and bits per RGB are OK,
     * this may be as simple as calling the framebuffer's ScreenInit()
     * function.  If not, the visuals will need to be setup before calling
     * a fb ScreenInit() function and fixed up after.
     *
     * For most PC hardware at depths >= 8, the defaults that fb uses
     * are not appropriate.  In this driver, we fixup the visuals after.
     */

    /*
     * Reset the visual list.
     */
    miClearVisualTypes();

    /* Setup the visuals we support. Only TrueColor. */
    ret = miSetVisualTypes(pScrn->depth,
                           miGetDefaultVisualMask(pScrn->depth),
                           pScrn->rgbBits, pScrn->defaultVisual);
    if (!ret)
        return FALSE;

    miSetPixmapDepths();

    pGlide->ShadowPitch =
            ((pScrn->virtualX * pScrn->bitsPerPixel >> 3) + 3) & ~3L;
    pGlide->ShadowPtr = xnfalloc(pGlide->ShadowPitch * pScrn->virtualY);

    /*
     * Call the framebuffer layer's ScreenInit function, and fill in other
     * pScreen fields.
     */
    ret = fbScreenInit(pScreen, pGlide->ShadowPtr,
                       pScrn->virtualX, pScrn->virtualY,
                       pScrn->xDpi, pScrn->yDpi,
                       pScrn->displayWidth,
                       pScrn->bitsPerPixel);
    if (!ret)
        return FALSE;

    /* Fixup RGB ordering */
    visual = pScreen->visuals + pScreen->numVisuals;
    while (--visual >= pScreen->visuals) {
        if ((visual->class | DynamicClass) == DirectColor) {
            visual->offsetRed = pScrn->offset.red;
            visual->offsetGreen = pScrn->offset.green;
            visual->offsetBlue = pScrn->offset.blue;
            visual->redMask = pScrn->mask.red;
            visual->greenMask = pScrn->mask.green;
            visual->blueMask = pScrn->mask.blue;
        }
    }

    /* must be after RGB ordering fixed */
    fbPictureInit(pScreen, 0, 0);

    xf86SetBlackWhitePixels(pScreen);
    xf86SetBackingStore(pScreen);

    /* Initialize software cursor. Must precede creation of the default
     * colormap */
    miDCInitialize(pScreen, xf86GetPointerScreenFuncs());

    /* Initialise default colourmap */
    if (!miCreateDefColormap(pScreen))
        return FALSE;

    ShadowFBInit(pScreen, GLIDERefreshArea);

    xf86DPMSInit(pScreen, GLIDEDisplayPowerManagementSet, 0);

    pScreen->SaveScreen = GLIDESaveScreen;

    /* Wrap the current CloseScreen function */
    pGlide->CloseScreen = pScreen->CloseScreen;
    pScreen->CloseScreen = GLIDECloseScreen;

    /* Report any unused options (only for the first generation) */
    if (serverGeneration == 1)
        xf86ShowUnusedOptions(pScrn->scrnIndex, pScrn->options);

    /* Done */
    return TRUE;
}

/*
 * This is called when VT switching back to the X server.  Its job is
 * to reinitialise the video mode.
 *
 * We may wish to unmap video/MMIO memory too.
 */
/* Mandatory */
static Bool
GLIDEEnterVT(VT_FUNC_ARGS_DECL)
{
    SCRN_INFO_PTR(arg);

    return GLIDEModeInit(pScrn, pScrn->currentMode);
}

/*
 * This is called when VT switching away from the X server.  Its job is
 * to restore the previous (text) mode.
 *
 * We may wish to remap video/MMIO memory too.
 */
/* Mandatory */
static void
GLIDELeaveVT(VT_FUNC_ARGS_DECL)
{
    SCRN_INFO_PTR(arg);

    GLIDERestore(pScrn, FALSE);
}

/*
 * This is called at the end of each server generation.  It restores the
 * original (text) mode.  It should also unmap the video memory, and free
 * any per-generation data allocated by the driver.  It should finish
 * by unwrapping and calling the saved CloseScreen function.
 */
/* Mandatory */
static Bool
GLIDECloseScreen(CLOSE_SCREEN_ARGS_DECL)
{
    ScrnInfoPtr pScrn = xf86ScreenToScrn(pScreen);
    GLIDEPtr pGlide = GLIDEPTR(pScrn);

    if (pScrn->vtSema)
        GLIDERestore(pScrn, TRUE);
    free(pGlide->ShadowPtr);

    pScrn->vtSema = FALSE;

    pScreen->CloseScreen = pGlide->CloseScreen;

    return (*pScreen->CloseScreen)(CLOSE_SCREEN_ARGS);
}

/*
 * Free up any persistent data structures
 */
/* Optional */
static void
GLIDEFreeScreen(FREE_SCREEN_ARGS_DECL)
{
    SCRN_INFO_PTR(arg);
    GLIDEPtr pGlide = GLIDEPTR(pScrn);

    /*
     * This only gets called when a screen is being deleted.  It does not
     * get called routinely at the end of a server generation.
     */
    if (pGlide && pGlide->ShadowPtr)
        free(pGlide->ShadowPtr);
    GLIDEFreeRec(pScrn);
}

/*
 * Do screen blanking
 */
/* Mandatory */
static Bool
GLIDESaveScreen(ScreenPtr pScreen, int mode)
{
    ScrnInfoPtr pScrn;
    GLIDEPtr pGlide;
    Bool unblank;

    unblank = xf86IsUnblank(mode);
    pScrn = xf86ScreenToScrn(pScreen);
    pGlide = GLIDEPTR(pScrn);
    pGlide->Blanked = !unblank;
    if (unblank)
        GLIDERefreshAll(pScrn);
    else
        grBufferClear(0, 0, GR_ZDEPTHVALUE_FARTHEST);

    return TRUE;
}

static Bool
GLIDEModeInit(ScrnInfoPtr pScrn, DisplayModePtr mode)
{
    GLIDEPtr pGlide;
    int ret;
    int width, height;
    double refresh;
    Bool match = FALSE;

    pGlide = GLIDEPTR(pScrn);

    if (mode->Flags & V_INTERLACE) {
        xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
                   "Interlaced modes not supported\n");
        return FALSE;
    }

    width = mode->HDisplay;
    height = mode->VDisplay;

#if 0
    ErrorF("mode->HDisplay = %d, pScrn->displayWidth = %d\n",
           mode->HDisplay, pScrn->displayWidth);
    ErrorF("mode->VDisplay = %d, mode->HTotal = %d, mode->VTotal = %d\n",
           mode->VDisplay, mode->HTotal, mode->VTotal);
    ErrorF("mode->Clock = %d\n", mode->Clock);
#endif

    if (width == 640 && height == 480) {
        match = TRUE;
        pGlide->grResolution = GR_RESOLUTION_640x480;
    }
    if (width == 800 && height == 600) {
        match = TRUE;
        pGlide->grResolution = GR_RESOLUTION_800x600;
    }
    if (width == 960 && height == 720) {
        match = TRUE;
        pGlide->grResolution = GR_RESOLUTION_960x720;
    }
    if (width == 1024 && height == 768) {
        match = TRUE;
        pGlide->grResolution = GR_RESOLUTION_1024x768;
    }
    if (width == 1280 && height == 1024) {
        match = TRUE;
        pGlide->grResolution = GR_RESOLUTION_1280x1024;
    }
    if (width == 1600 && height == 1200) {
        match = TRUE;
        pGlide->grResolution = GR_RESOLUTION_1600x1200;
    }

    if (!match) {
        xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
                   "Selected width = %d and height = %d is not supported by "
                   "glide\n", width, height);
        return FALSE;
    }

    refresh = (mode->Clock * 1.0e3) / ((double)(mode->HTotal) *
                                       (double)(mode->VTotal));
#if 0
    ErrorF("Calculated refresh rate for mode is %.2fHz\n", refresh);
#endif

    /* The Glide header files indicate there are a rather large number of
     * refresh rates available. In practice, though, only 60, 75 and 85Hz seem
     * to be available. If we try using another refresh rate, glide will
     * default to 60Hz. */
    pGlide->grRefreshRate = GR_REFRESH_60Hz;
    if (refresh > 74.0)
        pGlide->grRefreshRate = GR_REFRESH_75Hz;
    if (refresh > 84.0)
        pGlide->grRefreshRate = GR_REFRESH_85Hz;

    /* Initialize the video card */
    grGlideInit();
    grSstSelect(pGlide->SST_Index);

    ret = grSstWinOpen(0, pGlide->grResolution, pGlide->grRefreshRate,
                       GR_COLORFORMAT_ARGB, GR_ORIGIN_UPPER_LEFT, 2, 0);
    if (!ret) {
        xf86DrvMsg(pScrn->scrnIndex, X_ERROR, "grSstWinOpen returned %d. "
                   "You are probably trying to use a resolution that is not "
                   "supported by your hardware.", ret);
        return FALSE;
    }

    grRenderBuffer(GR_BUFFER_FRONTBUFFER);
    grClipWindow(0, 0, 1024, 768);
    grBufferClear(0, 0, GR_ZDEPTHVALUE_FARTHEST);

    pGlide->Blanked = FALSE;
    pGlide->GlideInitiated = TRUE;

    return TRUE;
}

static void
GLIDERestore(ScrnInfoPtr pScrn, Bool Closing)
{
    GLIDEPtr pGlide;

    pGlide = GLIDEPTR(pScrn);

    if (!(pGlide->GlideInitiated))
        return;

    pGlide->GlideInitiated = FALSE;
    pGlide->Blanked = TRUE;
    grBufferClear(0, 0, GR_ZDEPTHVALUE_FARTHEST);
    if (!Closing || !(pGlide->OnAtExit))
        grGlideShutdown();
}

static void
GLIDERefreshArea(ScrnInfoPtr pScrn, int num, BoxPtr pbox)
{
    GLIDEPtr pGlide = GLIDEPTR(pScrn);
    int Bpp;
    unsigned char *src;
    s32 x1, x2;

    if (pGlide->Blanked)
        return;

    Bpp = pScrn->bitsPerPixel >> 3;
    if (pScrn->bitsPerPixel == 16) {
        while (num--) {
            /* We align to an even number of pixels so we won't have to copy
             * half-words over the PCI bus */
            x1 = (pbox->x1) & ~1;
            x2 = (pbox->x2 + 1) & ~1;
            src = pGlide->ShadowPtr + (pbox->y1 * pGlide->ShadowPitch) +
                    (x1 * Bpp);
#if defined(GLIDE3) && defined(GLIDE3_ALPHA)
            grLfbWriteRegion(GR_BUFFER_FRONTBUFFER, x1, pbox->y1,
                             GR_LFB_SRC_FMT_565, x2 - x1, pbox->y2 - pbox->y1,
                             FALSE, pGlide->ShadowPitch, src);
#else
            grLfbWriteRegion(GR_BUFFER_FRONTBUFFER, x1, pbox->y1,
                             GR_LFB_SRC_FMT_565, x2 - x1, pbox->y2 - pbox->y1,
                             pGlide->ShadowPitch, src);
#endif
            pbox++;
        }
    }
    else {
        while (num--) {
            x1 = pbox->x1;
            x2 = pbox->x2;
            src = pGlide->ShadowPtr + (pbox->y1 * pGlide->ShadowPitch) +
                    (pbox->x1 * Bpp);
#if defined(GLIDE3) && defined(GLIDE3_ALPHA)
            grLfbWriteRegion(GR_BUFFER_FRONTBUFFER, x1, pbox->y1,
                             GR_LFB_SRC_FMT_888, x2 - x1, pbox->y2 - pbox->y1,
                             FALSE, pGlide->ShadowPitch, src);
#else
            grLfbWriteRegion(GR_BUFFER_FRONTBUFFER, x1, pbox->y1,
                             GR_LFB_SRC_FMT_888, x2 - x1, pbox->y2 - pbox->y1,
                             pGlide->ShadowPitch, src);
#endif
            pbox++;
        }
    }
}

/*
 * GLIDEDisplayPowerManagementSet --
 *
 * Sets VESA Display Power Management Signaling (DPMS) Mode.
 */
static void
GLIDEDisplayPowerManagementSet(ScrnInfoPtr pScrn, int PowerManagementMode,
                               int flags)
{
    GLIDEPtr pGlide = GLIDEPTR(pScrn);
    static int oldmode = -1;

#if 0
    ErrorF("GLIDEDisplayPowerManagementSet: %d\n", PowerManagementMode);
#endif

    if (oldmode == DPMSModeOff && PowerManagementMode != DPMSModeOff)
        GLIDEModeInit(pScrn, pScrn->currentMode);

    switch (PowerManagementMode) {
    case DPMSModeOn:
        /* Screen: On; HSync: On, VSync: On */
        pGlide->Blanked = FALSE;
        GLIDERefreshAll(pScrn);
        break;
    case DPMSModeStandby:
    case DPMSModeSuspend:
        pGlide->Blanked = TRUE;
        grBufferClear(0, 0, GR_ZDEPTHVALUE_FARTHEST);
        break;
    case DPMSModeOff:
        GLIDERestore(pScrn, FALSE);
        break;
    }
    oldmode = PowerManagementMode;
}

static void
GLIDERefreshAll(ScrnInfoPtr pScrn)
{
    BoxRec box;

    box.x1 = 0;
    box.x2 = pScrn->virtualX;
    box.y1 = 0;
    box.y2 = pScrn->virtualY;
    GLIDERefreshArea(pScrn, 1, &box);
}