/*
 * Copyright (c) Intel Corp. 2007.
 * All Rights Reserved.
 *
 * Intel funded Tungsten Graphics (http://www.tungstengraphics.com) to
 * develop this driver.
 *
 * This file is part of the Vermilion Range fb driver.
 * The Vermilion Range fb driver is free software;
 * you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * The Vermilion Range fb driver is distributed
 * in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this driver; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Authors:
 *   Thomas Hellström <thomas-at-tungstengraphics-dot-com>
 *   Michel Dänzer <michel-at-tungstengraphics-dot-com>
 *   Alan Hourihane <alanh-at-tungstengraphics-dot-com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/fb.h>
#include <linux/pci.h>
#include <asm/set_memory.h>
#include <asm/tlbflush.h>
#include <linux/mmzone.h>

/* #define VERMILION_DEBUG */

#include "vermilion.h"

#define MODULE_NAME "vmlfb"

#define VML_TOHW(_val, _width) ((((_val) << (_width)) + 0x7FFF - (_val)) >> 16)

static struct mutex vml_mutex;
static struct list_head global_no_mode;
static struct list_head global_has_mode;
static struct fb_ops vmlfb_ops;
static struct vml_sys *subsys = NULL;
static char *vml_default_mode = "1024x768@60";
static struct fb_videomode defaultmode = {
        NULL, 60, 1024, 768, 12896, 144, 24, 29, 3, 136, 6,
        0, FB_VMODE_NONINTERLACED
};

static u32 vml_mem_requested = (10 * 1024 * 1024);
static u32 vml_mem_contig = (4 * 1024 * 1024);
static u32 vml_mem_min = (4 * 1024 * 1024);

static u32 vml_clocks[] = {
        6750,
        13500,
        27000,
        29700,
        37125,
        54000,
        59400,
        74250,
        120000,
        148500
};

static u32 vml_num_clocks = ARRAY_SIZE(vml_clocks);

/*
 * Allocate a contiguous vram area and make its linear kernel map
 * uncached.
 */

static int vmlfb_alloc_vram_area(struct vram_area *va, unsigned max_order,
                                 unsigned min_order)
{
        gfp_t flags;
        unsigned long i;

        max_order++;
        do {
                /*
                 * Really try hard to get the needed memory.
                 * We need memory below the first 32MB, so we
                 * add the __GFP_DMA flag that guarantees that we are
                 * below the first 16MB.
                 */

                flags = __GFP_DMA | __GFP_HIGH | __GFP_KSWAPD_RECLAIM;
                va->logical =
                         __get_free_pages(flags, --max_order);
        } while (va->logical == 0 && max_order > min_order);

        if (!va->logical)
                return -ENOMEM;

        va->phys = virt_to_phys((void *)va->logical);
        va->size = PAGE_SIZE << max_order;
        va->order = max_order;

        /*
         * It seems like __get_free_pages only ups the usage count
         * of the first page. This doesn't work with fault mapping, so
         * up the usage count once more (XXX: should use split_page or
         * compound page).
         */

        memset((void *)va->logical, 0x00, va->size);
        for (i = va->logical; i < va->logical + va->size; i += PAGE_SIZE) {
                get_page(virt_to_page(i));
        }

        /*
         * Change caching policy of the linear kernel map to avoid
         * mapping type conflicts with user-space mappings.
         */
        set_pages_uc(virt_to_page(va->logical), va->size >> PAGE_SHIFT);

        printk(KERN_DEBUG MODULE_NAME
               ": Allocated %ld bytes vram area at 0x%08lx\n",
               va->size, va->phys);

        return 0;
}

/*
 * Free a contiguous vram area and reset its linear kernel map
 * mapping type.
 */

static void vmlfb_free_vram_area(struct vram_area *va)
{
        unsigned long j;

        if (va->logical) {

                /*
                 * Reset the linear kernel map caching policy.
                 */

                set_pages_wb(virt_to_page(va->logical),
                                 va->size >> PAGE_SHIFT);

                /*
                 * Decrease the usage count on the pages we've used
                 * to compensate for upping when allocating.
                 */

                for (j = va->logical; j < va->logical + va->size;
                     j += PAGE_SIZE) {
                        (void)put_page_testzero(virt_to_page(j));
                }

                printk(KERN_DEBUG MODULE_NAME
                       ": Freeing %ld bytes vram area at 0x%08lx\n",
                       va->size, va->phys);
                free_pages(va->logical, va->order);

                va->logical = 0;
        }
}

/*
 * Free allocated vram.
 */

static void vmlfb_free_vram(struct vml_info *vinfo)
{
        int i;

        for (i = 0; i < vinfo->num_areas; ++i) {
                vmlfb_free_vram_area(&vinfo->vram[i]);
        }
        vinfo->num_areas = 0;
}

/*
 * Allocate vram. Currently we try to allocate contiguous areas from the
 * __GFP_DMA zone and puzzle them together. A better approach would be to
 * allocate one contiguous area for scanout and use one-page allocations for
 * offscreen areas. This requires user-space and GPU virtual mappings.
 */

static int vmlfb_alloc_vram(struct vml_info *vinfo,
                            size_t requested,
                            size_t min_total, size_t min_contig)
{
        int i, j;
        int order;
        int contiguous;
        int err;
        struct vram_area *va;
        struct vram_area *va2;

        vinfo->num_areas = 0;
        for (i = 0; i < VML_VRAM_AREAS; ++i) {
                va = &vinfo->vram[i];
                order = 0;

                while (requested > (PAGE_SIZE << order) && order < MAX_ORDER)
                        order++;

                err = vmlfb_alloc_vram_area(va, order, 0);

                if (err)
                        break;

                if (i == 0) {
                        vinfo->vram_start = va->phys;
                        vinfo->vram_logical = (void __iomem *) va->logical;
                        vinfo->vram_contig_size = va->size;
                        vinfo->num_areas = 1;
                } else {
                        contiguous = 0;

                        for (j = 0; j < i; ++j) {
                                va2 = &vinfo->vram[j];
                                if (va->phys + va->size == va2->phys ||
                                    va2->phys + va2->size == va->phys) {
                                        contiguous = 1;
                                        break;
                                }
                        }

                        if (contiguous) {
                                vinfo->num_areas++;
                                if (va->phys < vinfo->vram_start) {
                                        vinfo->vram_start = va->phys;
                                        vinfo->vram_logical =
                                                (void __iomem *)va->logical;
                                }
                                vinfo->vram_contig_size += va->size;
                        } else {
                                vmlfb_free_vram_area(va);
                                break;
                        }
                }

                if (requested < va->size)
                        break;
                else
                        requested -= va->size;
        }

        if (vinfo->vram_contig_size > min_total &&
            vinfo->vram_contig_size > min_contig) {

                printk(KERN_DEBUG MODULE_NAME
                       ": Contiguous vram: %ld bytes at physical 0x%08lx.\n",
                       (unsigned long)vinfo->vram_contig_size,
                       (unsigned long)vinfo->vram_start);

                return 0;
        }

        printk(KERN_ERR MODULE_NAME
               ": Could not allocate requested minimal amount of vram.\n");

        vmlfb_free_vram(vinfo);

        return -ENOMEM;
}

/*
 * Find the GPU to use with our display controller.
 */

static int vmlfb_get_gpu(struct vml_par *par)
{
        mutex_lock(&vml_mutex);

        par->gpu = pci_get_device(PCI_VENDOR_ID_INTEL, VML_DEVICE_GPU, NULL);

        if (!par->gpu) {
                mutex_unlock(&vml_mutex);
                return -ENODEV;
        }

        mutex_unlock(&vml_mutex);

        if (pci_enable_device(par->gpu) < 0)
                return -ENODEV;

        return 0;
}

/*
 * Find a contiguous vram area that contains a given offset from vram start.
 */
static int vmlfb_vram_offset(struct vml_info *vinfo, unsigned long offset)
{
        unsigned long aoffset;
        unsigned i;

        for (i = 0; i < vinfo->num_areas; ++i) {
                aoffset = offset - (vinfo->vram[i].phys - vinfo->vram_start);

                if (aoffset < vinfo->vram[i].size) {
                        return 0;
                }
        }

        return -EINVAL;
}

/*
 * Remap the MMIO register spaces of the VDC and the GPU.
 */

static int vmlfb_enable_mmio(struct vml_par *par)
{
        int err;

        par->vdc_mem_base = pci_resource_start(par->vdc, 0);
        par->vdc_mem_size = pci_resource_len(par->vdc, 0);
        if (!request_mem_region(par->vdc_mem_base, par->vdc_mem_size, "vmlfb")) {
                printk(KERN_ERR MODULE_NAME
                       ": Could not claim display controller MMIO.\n");
                return -EBUSY;
        }
        par->vdc_mem = ioremap_nocache(par->vdc_mem_base, par->vdc_mem_size);
        if (par->vdc_mem == NULL) {
                printk(KERN_ERR MODULE_NAME
                       ": Could not map display controller MMIO.\n");
                err = -ENOMEM;
                goto out_err_0;
        }

        par->gpu_mem_base = pci_resource_start(par->gpu, 0);
        par->gpu_mem_size = pci_resource_len(par->gpu, 0);
        if (!request_mem_region(par->gpu_mem_base, par->gpu_mem_size, "vmlfb")) {
                printk(KERN_ERR MODULE_NAME ": Could not claim GPU MMIO.\n");
                err = -EBUSY;
                goto out_err_1;
        }
        par->gpu_mem = ioremap_nocache(par->gpu_mem_base, par->gpu_mem_size);
        if (par->gpu_mem == NULL) {
                printk(KERN_ERR MODULE_NAME ": Could not map GPU MMIO.\n");
                err = -ENOMEM;
                goto out_err_2;
        }

        return 0;

out_err_2:
        release_mem_region(par->gpu_mem_base, par->gpu_mem_size);
out_err_1:
        iounmap(par->vdc_mem);
out_err_0:
        release_mem_region(par->vdc_mem_base, par->vdc_mem_size);
        return err;
}

/*
 * Unmap the VDC and GPU register spaces.
 */

static void vmlfb_disable_mmio(struct vml_par *par)
{
        iounmap(par->gpu_mem);
        release_mem_region(par->gpu_mem_base, par->gpu_mem_size);
        iounmap(par->vdc_mem);
        release_mem_region(par->vdc_mem_base, par->vdc_mem_size);
}

/*
 * Release and uninit the VDC and GPU.
 */

static void vmlfb_release_devices(struct vml_par *par)
{
        if (atomic_dec_and_test(&par->refcount)) {
                pci_disable_device(par->gpu);
                pci_disable_device(par->vdc);
        }
}

/*
 * Free up allocated resources for a device.
 */

static void vml_pci_remove(struct pci_dev *dev)
{
        struct fb_info *info;
        struct vml_info *vinfo;
        struct vml_par *par;

        info = pci_get_drvdata(dev);
        if (info) {
                vinfo = container_of(info, struct vml_info, info);
                par = vinfo->par;
                mutex_lock(&vml_mutex);
                unregister_framebuffer(info);
                fb_dealloc_cmap(&info->cmap);
                vmlfb_free_vram(vinfo);
                vmlfb_disable_mmio(par);
                vmlfb_release_devices(par);
                kfree(vinfo);
                kfree(par);
                mutex_unlock(&vml_mutex);
        }
}

static void vmlfb_set_pref_pixel_format(struct fb_var_screeninfo *var)
{
        switch (var->bits_per_pixel) {
        case 16:
                var->blue.offset = 0;
                var->blue.length = 5;
                var->green.offset = 5;
                var->green.length = 5;
                var->red.offset = 10;
                var->red.length = 5;
                var->transp.offset = 15;
                var->transp.length = 1;
                break;
        case 32:
                var->blue.offset = 0;
                var->blue.length = 8;
                var->green.offset = 8;
                var->green.length = 8;
                var->red.offset = 16;
                var->red.length = 8;
                var->transp.offset = 24;
                var->transp.length = 0;
                break;
        default:
                break;
        }

        var->blue.msb_right = var->green.msb_right =
            var->red.msb_right = var->transp.msb_right = 0;
}

/*
 * Device initialization.
 * We initialize one vml_par struct per device and one vml_info
 * struct per pipe. Currently we have only one pipe.
 */

static int vml_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
        struct vml_info *vinfo;
        struct fb_info *info;
        struct vml_par *par;
        int err = 0;

        par = kzalloc(sizeof(*par), GFP_KERNEL);
        if (par == NULL)
                return -ENOMEM;

        vinfo = kzalloc(sizeof(*vinfo), GFP_KERNEL);
        if (vinfo == NULL) {
                err = -ENOMEM;
                goto out_err_0;
        }

        vinfo->par = par;
        par->vdc = dev;
        atomic_set(&par->refcount, 1);

        switch (id->device) {
        case VML_DEVICE_VDC:
                if ((err = vmlfb_get_gpu(par)))
                        goto out_err_1;
                pci_set_drvdata(dev, &vinfo->info);
                break;
        default:
                err = -ENODEV;
                goto out_err_1;
        }

        info = &vinfo->info;
        info->flags = FBINFO_DEFAULT | FBINFO_PARTIAL_PAN_OK;

        err = vmlfb_enable_mmio(par);
        if (err)
                goto out_err_2;

        err = vmlfb_alloc_vram(vinfo, vml_mem_requested,
                               vml_mem_contig, vml_mem_min);
        if (err)
                goto out_err_3;

        strcpy(info->fix.id, "Vermilion Range");
        info->fix.mmio_start = 0;
        info->fix.mmio_len = 0;
        info->fix.smem_start = vinfo->vram_start;
        info->fix.smem_len = vinfo->vram_contig_size;
        info->fix.type = FB_TYPE_PACKED_PIXELS;
        info->fix.visual = FB_VISUAL_TRUECOLOR;
        info->fix.ypanstep = 1;
        info->fix.xpanstep = 1;
        info->fix.ywrapstep = 0;
        info->fix.accel = FB_ACCEL_NONE;
        info->screen_base = vinfo->vram_logical;
        info->pseudo_palette = vinfo->pseudo_palette;
        info->par = par;
        info->fbops = &vmlfb_ops;
        info->device = &dev->dev;

        INIT_LIST_HEAD(&vinfo->head);
        vinfo->pipe_disabled = 1;
        vinfo->cur_blank_mode = FB_BLANK_UNBLANK;

        info->var.grayscale = 0;
        info->var.bits_per_pixel = 16;
        vmlfb_set_pref_pixel_format(&info->var);

        if (!fb_find_mode
            (&info->var, info, vml_default_mode, NULL, 0, &defaultmode, 16)) {
                printk(KERN_ERR MODULE_NAME ": Could not find initial mode\n");
        }

        if (fb_alloc_cmap(&info->cmap, 256, 1) < 0) {
                err = -ENOMEM;
                goto out_err_4;
        }

        err = register_framebuffer(info);
        if (err) {
                printk(KERN_ERR MODULE_NAME ": Register framebuffer error.\n");
                goto out_err_5;
        }

        printk("Initialized vmlfb\n");

        return 0;

out_err_5:
        fb_dealloc_cmap(&info->cmap);
out_err_4:
        vmlfb_free_vram(vinfo);
out_err_3:
        vmlfb_disable_mmio(par);
out_err_2:
        vmlfb_release_devices(par);
out_err_1:
        kfree(vinfo);
out_err_0:
        kfree(par);
        return err;
}

static int vmlfb_open(struct fb_info *info, int user)
{
        /*
         * Save registers here?
         */
        return 0;
}

static int vmlfb_release(struct fb_info *info, int user)
{
        /*
         * Restore registers here.
         */

        return 0;
}

static int vml_nearest_clock(int clock)
{

        int i;
        int cur_index;
        int cur_diff;
        int diff;

        cur_index = 0;
        cur_diff = clock - vml_clocks[0];
        cur_diff = (cur_diff < 0) ? -cur_diff : cur_diff;
        for (i = 1; i < vml_num_clocks; ++i) {
                diff = clock - vml_clocks[i];
                diff = (diff < 0) ? -diff : diff;
                if (diff < cur_diff) {
                        cur_index = i;
                        cur_diff = diff;
                }
        }
        return vml_clocks[cur_index];
}

static int vmlfb_check_var_locked(struct fb_var_screeninfo *var,
                                  struct vml_info *vinfo)
{
        u32 pitch;
        u64 mem;
        int nearest_clock;
        int clock;
        int clock_diff;
        struct fb_var_screeninfo v;

        v = *var;
        clock = PICOS2KHZ(var->pixclock);

        if (subsys && subsys->nearest_clock) {
                nearest_clock = subsys->nearest_clock(subsys, clock);
        } else {
                nearest_clock = vml_nearest_clock(clock);
        }

        /*
         * Accept a 20% diff.
         */

        clock_diff = nearest_clock - clock;
        clock_diff = (clock_diff < 0) ? -clock_diff : clock_diff;
        if (clock_diff > clock / 5) {
#if 0
                printk(KERN_DEBUG MODULE_NAME ": Diff failure. %d %d\n",clock_diff,clock);
#endif
                return -EINVAL;
        }

        v.pixclock = KHZ2PICOS(nearest_clock);

        if (var->xres > VML_MAX_XRES || var->yres > VML_MAX_YRES) {
                printk(KERN_DEBUG MODULE_NAME ": Resolution failure.\n");
                return -EINVAL;
        }
        if (var->xres_virtual > VML_MAX_XRES_VIRTUAL) {
                printk(KERN_DEBUG MODULE_NAME
                       ": Virtual resolution failure.\n");
                return -EINVAL;
        }
        switch (v.bits_per_pixel) {
        case 0 ... 16:
                v.bits_per_pixel = 16;
                break;
        case 17 ... 32:
                v.bits_per_pixel = 32;
                break;
        default:
                printk(KERN_DEBUG MODULE_NAME ": Invalid bpp: %d.\n",
                       var->bits_per_pixel);
                return -EINVAL;
        }

        pitch = ALIGN((var->xres * var->bits_per_pixel) >> 3, 0x40);
        mem = pitch * var->yres_virtual;
        if (mem > vinfo->vram_contig_size) {
                return -ENOMEM;
        }

        switch (v.bits_per_pixel) {
        case 16:
                if (var->blue.offset != 0 ||
                    var->blue.length != 5 ||
                    var->green.offset != 5 ||
                    var->green.length != 5 ||
                    var->red.offset != 10 ||
                    var->red.length != 5 ||
                    var->transp.offset != 15 || var->transp.length != 1) {
                        vmlfb_set_pref_pixel_format(&v);
                }
                break;
        case 32:
                if (var->blue.offset != 0 ||
                    var->blue.length != 8 ||
                    var->green.offset != 8 ||
                    var->green.length != 8 ||
                    var->red.offset != 16 ||
                    var->red.length != 8 ||
                    (var->transp.length != 0 && var->transp.length != 8) ||
                    (var->transp.length == 8 && var->transp.offset != 24)) {
                        vmlfb_set_pref_pixel_format(&v);
                }
                break;
        default:
                return -EINVAL;
        }

        *var = v;

        return 0;
}

static int vmlfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
        struct vml_info *vinfo = container_of(info, struct vml_info, info);
        int ret;

        mutex_lock(&vml_mutex);
        ret = vmlfb_check_var_locked(var, vinfo);
        mutex_unlock(&vml_mutex);

        return ret;
}

static void vml_wait_vblank(struct vml_info *vinfo)
{
        /* Wait for vblank. For now, just wait for a 50Hz cycle (20ms)) */
        mdelay(20);
}

static void vmlfb_disable_pipe(struct vml_info *vinfo)
{
        struct vml_par *par = vinfo->par;

        /* Disable the MDVO pad */
        VML_WRITE32(par, VML_RCOMPSTAT, 0);
        while (!(VML_READ32(par, VML_RCOMPSTAT) & VML_MDVO_VDC_I_RCOMP)) ;

        /* Disable display planes */
        VML_WRITE32(par, VML_DSPCCNTR,
                    VML_READ32(par, VML_DSPCCNTR) & ~VML_GFX_ENABLE);
        (void)VML_READ32(par, VML_DSPCCNTR);
        /* Wait for vblank for the disable to take effect */
        vml_wait_vblank(vinfo);

        /* Next, disable display pipes */
        VML_WRITE32(par, VML_PIPEACONF, 0);
        (void)VML_READ32(par, VML_PIPEACONF);

        vinfo->pipe_disabled = 1;
}

#ifdef VERMILION_DEBUG
static void vml_dump_regs(struct vml_info *vinfo)
{
        struct vml_par *par = vinfo->par;

        printk(KERN_DEBUG MODULE_NAME ": Modesetting register dump:\n");
        printk(KERN_DEBUG MODULE_NAME ": \tHTOTAL_A         : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_HTOTAL_A));
        printk(KERN_DEBUG MODULE_NAME ": \tHBLANK_A         : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_HBLANK_A));
        printk(KERN_DEBUG MODULE_NAME ": \tHSYNC_A          : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_HSYNC_A));
        printk(KERN_DEBUG MODULE_NAME ": \tVTOTAL_A         : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_VTOTAL_A));
        printk(KERN_DEBUG MODULE_NAME ": \tVBLANK_A         : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_VBLANK_A));
        printk(KERN_DEBUG MODULE_NAME ": \tVSYNC_A          : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_VSYNC_A));
        printk(KERN_DEBUG MODULE_NAME ": \tDSPCSTRIDE       : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_DSPCSTRIDE));
        printk(KERN_DEBUG MODULE_NAME ": \tDSPCSIZE         : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_DSPCSIZE));
        printk(KERN_DEBUG MODULE_NAME ": \tDSPCPOS          : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_DSPCPOS));
        printk(KERN_DEBUG MODULE_NAME ": \tDSPARB           : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_DSPARB));
        printk(KERN_DEBUG MODULE_NAME ": \tDSPCADDR         : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_DSPCADDR));
        printk(KERN_DEBUG MODULE_NAME ": \tBCLRPAT_A        : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_BCLRPAT_A));
        printk(KERN_DEBUG MODULE_NAME ": \tCANVSCLR_A       : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_CANVSCLR_A));
        printk(KERN_DEBUG MODULE_NAME ": \tPIPEASRC         : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_PIPEASRC));
        printk(KERN_DEBUG MODULE_NAME ": \tPIPEACONF        : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_PIPEACONF));
        printk(KERN_DEBUG MODULE_NAME ": \tDSPCCNTR         : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_DSPCCNTR));
        printk(KERN_DEBUG MODULE_NAME ": \tRCOMPSTAT        : 0x%08x\n",
               (unsigned)VML_READ32(par, VML_RCOMPSTAT));
        printk(KERN_DEBUG MODULE_NAME ": End of modesetting register dump.\n");
}
#endif

static int vmlfb_set_par_locked(struct vml_info *vinfo)
{
        struct vml_par *par = vinfo->par;
        struct fb_info *info = &vinfo->info;
        struct fb_var_screeninfo *var = &info->var;
        u32 htotal, hactive, hblank_start, hblank_end, hsync_start, hsync_end;
        u32 vtotal, vactive, vblank_start, vblank_end, vsync_start, vsync_end;
        u32 dspcntr;
        int clock;

        vinfo->bytes_per_pixel = var->bits_per_pixel >> 3;
        vinfo->stride = ALIGN(var->xres_virtual * vinfo->bytes_per_pixel, 0x40);
        info->fix.line_length = vinfo->stride;

        if (!subsys)
                return 0;

        htotal =
            var->xres + var->right_margin + var->hsync_len + var->left_margin;
        hactive = var->xres;
        hblank_start = var->xres;
        hblank_end = htotal;
        hsync_start = hactive + var->right_margin;
        hsync_end = hsync_start + var->hsync_len;

        vtotal =
            var->yres + var->lower_margin + var->vsync_len + var->upper_margin;
        vactive = var->yres;
        vblank_start = var->yres;
        vblank_end = vtotal;
        vsync_start = vactive + var->lower_margin;
        vsync_end = vsync_start + var->vsync_len;

        dspcntr = VML_GFX_ENABLE | VML_GFX_GAMMABYPASS;
        clock = PICOS2KHZ(var->pixclock);

        if (subsys->nearest_clock) {
                clock = subsys->nearest_clock(subsys, clock);
        } else {
                clock = vml_nearest_clock(clock);
        }
        printk(KERN_DEBUG MODULE_NAME
               ": Set mode Hfreq : %d kHz, Vfreq : %d Hz.\n", clock / htotal,
               ((clock / htotal) * 1000) / vtotal);

        switch (var->bits_per_pixel) {
        case 16:
                dspcntr |= VML_GFX_ARGB1555;
                break;
        case 32:
                if (var->transp.length == 8)
                        dspcntr |= VML_GFX_ARGB8888 | VML_GFX_ALPHAMULT;
                else
                        dspcntr |= VML_GFX_RGB0888;
                break;
        default:
                return -EINVAL;
        }

        vmlfb_disable_pipe(vinfo);
        mb();

        if (subsys->set_clock)
                subsys->set_clock(subsys, clock);
        else
                return -EINVAL;

        VML_WRITE32(par, VML_HTOTAL_A, ((htotal - 1) << 16) | (hactive - 1));
        VML_WRITE32(par, VML_HBLANK_A,
                    ((hblank_end - 1) << 16) | (hblank_start - 1));
        VML_WRITE32(par, VML_HSYNC_A,
                    ((hsync_end - 1) << 16) | (hsync_start - 1));
        VML_WRITE32(par, VML_VTOTAL_A, ((vtotal - 1) << 16) | (vactive - 1));
        VML_WRITE32(par, VML_VBLANK_A,
                    ((vblank_end - 1) << 16) | (vblank_start - 1));
        VML_WRITE32(par, VML_VSYNC_A,
                    ((vsync_end - 1) << 16) | (vsync_start - 1));
        VML_WRITE32(par, VML_DSPCSTRIDE, vinfo->stride);
        VML_WRITE32(par, VML_DSPCSIZE,
                    ((var->yres - 1) << 16) | (var->xres - 1));
        VML_WRITE32(par, VML_DSPCPOS, 0x00000000);
        VML_WRITE32(par, VML_DSPARB, VML_FIFO_DEFAULT);
        VML_WRITE32(par, VML_BCLRPAT_A, 0x00000000);
        VML_WRITE32(par, VML_CANVSCLR_A, 0x00000000);
        VML_WRITE32(par, VML_PIPEASRC,
                    ((var->xres - 1) << 16) | (var->yres - 1));

        wmb();
        VML_WRITE32(par, VML_PIPEACONF, VML_PIPE_ENABLE);
        wmb();
        VML_WRITE32(par, VML_DSPCCNTR, dspcntr);
        wmb();
        VML_WRITE32(par, VML_DSPCADDR, (u32) vinfo->vram_start +
                    var->yoffset * vinfo->stride +
                    var->xoffset * vinfo->bytes_per_pixel);

        VML_WRITE32(par, VML_RCOMPSTAT, VML_MDVO_PAD_ENABLE);

        while (!(VML_READ32(par, VML_RCOMPSTAT) &
                 (VML_MDVO_VDC_I_RCOMP | VML_MDVO_PAD_ENABLE))) ;

        vinfo->pipe_disabled = 0;
#ifdef VERMILION_DEBUG
        vml_dump_regs(vinfo);
#endif

        return 0;
}

static int vmlfb_set_par(struct fb_info *info)
{
        struct vml_info *vinfo = container_of(info, struct vml_info, info);
        int ret;

        mutex_lock(&vml_mutex);
        list_move(&vinfo->head, (subsys) ? &global_has_mode : &global_no_mode);
        ret = vmlfb_set_par_locked(vinfo);

        mutex_unlock(&vml_mutex);
        return ret;
}

static int vmlfb_blank_locked(struct vml_info *vinfo)
{
        struct vml_par *par = vinfo->par;
        u32 cur = VML_READ32(par, VML_PIPEACONF);

        switch (vinfo->cur_blank_mode) {
        case FB_BLANK_UNBLANK:
                if (vinfo->pipe_disabled) {
                        vmlfb_set_par_locked(vinfo);
                }
                VML_WRITE32(par, VML_PIPEACONF, cur & ~VML_PIPE_FORCE_BORDER);
                (void)VML_READ32(par, VML_PIPEACONF);
                break;
        case FB_BLANK_NORMAL:
                if (vinfo->pipe_disabled) {
                        vmlfb_set_par_locked(vinfo);
                }
                VML_WRITE32(par, VML_PIPEACONF, cur | VML_PIPE_FORCE_BORDER);
                (void)VML_READ32(par, VML_PIPEACONF);
                break;
        case FB_BLANK_VSYNC_SUSPEND:
        case FB_BLANK_HSYNC_SUSPEND:
                if (!vinfo->pipe_disabled) {
                        vmlfb_disable_pipe(vinfo);
                }
                break;
        case FB_BLANK_POWERDOWN:
                if (!vinfo->pipe_disabled) {
                        vmlfb_disable_pipe(vinfo);
                }
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int vmlfb_blank(int blank_mode, struct fb_info *info)
{
        struct vml_info *vinfo = container_of(info, struct vml_info, info);
        int ret;

        mutex_lock(&vml_mutex);
        vinfo->cur_blank_mode = blank_mode;
        ret = vmlfb_blank_locked(vinfo);
        mutex_unlock(&vml_mutex);
        return ret;
}

static int vmlfb_pan_display(struct fb_var_screeninfo *var,
                             struct fb_info *info)
{
        struct vml_info *vinfo = container_of(info, struct vml_info, info);
        struct vml_par *par = vinfo->par;

        mutex_lock(&vml_mutex);
        VML_WRITE32(par, VML_DSPCADDR, (u32) vinfo->vram_start +
                    var->yoffset * vinfo->stride +
                    var->xoffset * vinfo->bytes_per_pixel);
        (void)VML_READ32(par, VML_DSPCADDR);
        mutex_unlock(&vml_mutex);

        return 0;
}

static int vmlfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                           u_int transp, struct fb_info *info)
{
        u32 v;

        if (regno >= 16)
                return -EINVAL;

        if (info->var.grayscale) {
                red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8;
        }

        if (info->fix.visual != FB_VISUAL_TRUECOLOR)
                return -EINVAL;

        red = VML_TOHW(red, info->var.red.length);
        blue = VML_TOHW(blue, info->var.blue.length);
        green = VML_TOHW(green, info->var.green.length);
        transp = VML_TOHW(transp, info->var.transp.length);

        v = (red << info->var.red.offset) |
            (green << info->var.green.offset) |
            (blue << info->var.blue.offset) |
            (transp << info->var.transp.offset);

        switch (info->var.bits_per_pixel) {
        case 16:
                ((u32 *) info->pseudo_palette)[regno] = v;
                break;
        case 24:
        case 32:
                ((u32 *) info->pseudo_palette)[regno] = v;
                break;
        }
        return 0;
}

static int vmlfb_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
        struct vml_info *vinfo = container_of(info, struct vml_info, info);
        unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
        int ret;
        unsigned long prot;

        ret = vmlfb_vram_offset(vinfo, offset);
        if (ret)
                return -EINVAL;

        prot = pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK;
        pgprot_val(vma->vm_page_prot) =
                prot | cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS);

        return vm_iomap_memory(vma, vinfo->vram_start,
                        vinfo->vram_contig_size);
}

static int vmlfb_sync(struct fb_info *info)
{
        return 0;
}

static int vmlfb_cursor(struct fb_info *info, struct fb_cursor *cursor)
{
        return -EINVAL; /* just to force soft_cursor() call */
}

static struct fb_ops vmlfb_ops = {
        .owner = THIS_MODULE,
        .fb_open = vmlfb_open,
        .fb_release = vmlfb_release,
        .fb_check_var = vmlfb_check_var,
        .fb_set_par = vmlfb_set_par,
        .fb_blank = vmlfb_blank,
        .fb_pan_display = vmlfb_pan_display,
        .fb_fillrect = cfb_fillrect,
        .fb_copyarea = cfb_copyarea,
        .fb_imageblit = cfb_imageblit,
        .fb_cursor = vmlfb_cursor,
        .fb_sync = vmlfb_sync,
        .fb_mmap = vmlfb_mmap,
        .fb_setcolreg = vmlfb_setcolreg
};

static struct pci_device_id vml_ids[] = {
        {PCI_DEVICE(PCI_VENDOR_ID_INTEL, VML_DEVICE_VDC)},
        {0}
};

static struct pci_driver vmlfb_pci_driver = {
        .name = "vmlfb",
        .id_table = vml_ids,
        .probe = vml_pci_probe,
        .remove = vml_pci_remove,
};

static void __exit vmlfb_cleanup(void)
{
        pci_unregister_driver(&vmlfb_pci_driver);
}

static int __init vmlfb_init(void)
{

#ifndef MODULE
        char *option = NULL;

        if (fb_get_options(MODULE_NAME, &option))
                return -ENODEV;
#endif

        printk(KERN_DEBUG MODULE_NAME ": initializing\n");
        mutex_init(&vml_mutex);
        INIT_LIST_HEAD(&global_no_mode);
        INIT_LIST_HEAD(&global_has_mode);

        return pci_register_driver(&vmlfb_pci_driver);
}

int vmlfb_register_subsys(struct vml_sys *sys)
{
        struct vml_info *entry;
        struct list_head *list;
        u32 save_activate;

        mutex_lock(&vml_mutex);
        if (subsys != NULL) {
                subsys->restore(subsys);
        }
        subsys = sys;
        subsys->save(subsys);

        /*
         * We need to restart list traversal for each item, since we
         * release the list mutex in the loop.
         */

        list = global_no_mode.next;
        while (list != &global_no_mode) {
                list_del_init(list);
                entry = list_entry(list, struct vml_info, head);

                /*
                 * First, try the current mode which might not be
                 * completely validated with respect to the pixel clock.
                 */

                if (!vmlfb_check_var_locked(&entry->info.var, entry)) {
                        vmlfb_set_par_locked(entry);
                        list_add_tail(list, &global_has_mode);
                } else {

                        /*
                         * Didn't work. Try to find another mode,
                         * that matches this subsys.
                         */

                        mutex_unlock(&vml_mutex);
                        save_activate = entry->info.var.activate;
                        entry->info.var.bits_per_pixel = 16;
                        vmlfb_set_pref_pixel_format(&entry->info.var);
                        if (fb_find_mode(&entry->info.var,
                                         &entry->info,
                                         vml_default_mode, NULL, 0, NULL, 16)) {
                                entry->info.var.activate |=
                                    FB_ACTIVATE_FORCE | FB_ACTIVATE_NOW;
                                fb_set_var(&entry->info, &entry->info.var);
                        } else {
                                printk(KERN_ERR MODULE_NAME
                                       ": Sorry. no mode found for this subsys.\n");
                        }
                        entry->info.var.activate = save_activate;
                        mutex_lock(&vml_mutex);
                }
                vmlfb_blank_locked(entry);
                list = global_no_mode.next;
        }
        mutex_unlock(&vml_mutex);

        printk(KERN_DEBUG MODULE_NAME ": Registered %s subsystem.\n",
                                subsys->name ? subsys->name : "unknown");
        return 0;
}

EXPORT_SYMBOL_GPL(vmlfb_register_subsys);

void vmlfb_unregister_subsys(struct vml_sys *sys)
{
        struct vml_info *entry, *next;

        mutex_lock(&vml_mutex);
        if (subsys != sys) {
                mutex_unlock(&vml_mutex);
                return;
        }
        subsys->restore(subsys);
        subsys = NULL;
        list_for_each_entry_safe(entry, next, &global_has_mode, head) {
                printk(KERN_DEBUG MODULE_NAME ": subsys disable pipe\n");
                vmlfb_disable_pipe(entry);
                list_move_tail(&entry->head, &global_no_mode);
        }
        mutex_unlock(&vml_mutex);
}

EXPORT_SYMBOL_GPL(vmlfb_unregister_subsys);

module_init(vmlfb_init);
module_exit(vmlfb_cleanup);

MODULE_AUTHOR("Tungsten Graphics");
MODULE_DESCRIPTION("Initialization of the Vermilion display devices");
MODULE_VERSION("1.0.0");
MODULE_LICENSE("GPL");