/*
 * framebuffer driver for VBE 2.0 compliant graphic boards
 *
 * switching to graphics mode happens at boot time (while
 * running in real mode, see arch/i386/boot/video.S).
 *
 * (c) 1998 Gerd Knorr <kraxel@goldbach.in-berlin.de>
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/fb.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/screen_info.h>

#include <video/vga.h>
#include <asm/io.h>
#include <asm/mtrr.h>

#define dac_reg (0x3c8)
#define dac_val (0x3c9)

/* --------------------------------------------------------------------- */

static struct fb_var_screeninfo vesafb_defined = {
        .activate       = FB_ACTIVATE_NOW,
        .height         = -1,
        .width          = -1,
        .right_margin   = 32,
        .upper_margin   = 16,
        .lower_margin   = 4,
        .vsync_len      = 4,
        .vmode          = FB_VMODE_NONINTERLACED,
};

static struct fb_fix_screeninfo vesafb_fix = {
        .id     = "VESA VGA",
        .type   = FB_TYPE_PACKED_PIXELS,
        .accel  = FB_ACCEL_NONE,
};

static int   inverse    __read_mostly;
static int   mtrr       __read_mostly;          /* disable mtrr */
static int   vram_remap;                        /* Set amount of memory to be used */
static int   vram_total;                        /* Set total amount of memory */
static int   pmi_setpal __read_mostly = 1;      /* pmi for palette changes ??? */
static int   ypan       __read_mostly;          /* 0..nothing, 1..ypan, 2..ywrap */
static void  (*pmi_start)(void) __read_mostly;
static void  (*pmi_pal)  (void) __read_mostly;
static int   depth      __read_mostly;
static int   vga_compat __read_mostly;
/* --------------------------------------------------------------------- */

static int vesafb_pan_display(struct fb_var_screeninfo *var,
                              struct fb_info *info)
{
#ifdef __i386__
        int offset;

        offset = (var->yoffset * info->fix.line_length + var->xoffset) / 4;

        __asm__ __volatile__(
                "call *(%%edi)"
                : /* no return value */
                : "a" (0x4f07),         /* EAX */
                  "b" (0),              /* EBX */
                  "c" (offset),         /* ECX */
                  "d" (offset >> 16),   /* EDX */
                  "D" (&pmi_start));    /* EDI */
#endif
        return 0;
}

static int vesa_setpalette(int regno, unsigned red, unsigned green,
                            unsigned blue)
{
        int shift = 16 - depth;
        int err = -EINVAL;

/*
 * Try VGA registers first...
 */
        if (vga_compat) {
                outb_p(regno,       dac_reg);
                outb_p(red   >> shift, dac_val);
                outb_p(green >> shift, dac_val);
                outb_p(blue  >> shift, dac_val);
                err = 0;
        }

#ifdef __i386__
/*
 * Fallback to the PMI....
 */
        if (err && pmi_setpal) {
                struct { u_char blue, green, red, pad; } entry;

                entry.red   = red   >> shift;
                entry.green = green >> shift;
                entry.blue  = blue  >> shift;
                entry.pad   = 0;
                __asm__ __volatile__(
                "call *(%%esi)"
                : /* no return value */
                : "a" (0x4f09),         /* EAX */
                  "b" (0),              /* EBX */
                  "c" (1),              /* ECX */
                  "d" (regno),          /* EDX */
                  "D" (&entry),         /* EDI */
                  "S" (&pmi_pal));      /* ESI */
                err = 0;
        }
#endif

        return err;
}

static int vesafb_setcolreg(unsigned regno, unsigned red, unsigned green,
                            unsigned blue, unsigned transp,
                            struct fb_info *info)
{
        int err = 0;

        /*
         *  Set a single color register. The values supplied are
         *  already rounded down to the hardware's capabilities
         *  (according to the entries in the `var' structure). Return
         *  != 0 for invalid regno.
         */
        
        if (regno >= info->cmap.len)
                return 1;

        if (info->var.bits_per_pixel == 8)
                err = vesa_setpalette(regno,red,green,blue);
        else if (regno < 16) {
                switch (info->var.bits_per_pixel) {
                case 16:
                        if (info->var.red.offset == 10) {
                                /* 1:5:5:5 */
                                ((u32*) (info->pseudo_palette))[regno] =
                                        ((red   & 0xf800) >>  1) |
                                        ((green & 0xf800) >>  6) |
                                        ((blue  & 0xf800) >> 11);
                        } else {
                                /* 0:5:6:5 */
                                ((u32*) (info->pseudo_palette))[regno] =
                                        ((red   & 0xf800)      ) |
                                        ((green & 0xfc00) >>  5) |
                                        ((blue  & 0xf800) >> 11);
                        }
                        break;
                case 24:
                case 32:
                        red   >>= 8;
                        green >>= 8;
                        blue  >>= 8;
                        ((u32 *)(info->pseudo_palette))[regno] =
                                (red   << info->var.red.offset)   |
                                (green << info->var.green.offset) |
                                (blue  << info->var.blue.offset);
                        break;
                }
        }

        return err;
}

static void vesafb_destroy(struct fb_info *info)
{
        fb_dealloc_cmap(&info->cmap);
        if (info->screen_base)
                iounmap(info->screen_base);
        release_mem_region(info->apertures->ranges[0].base, info->apertures->ranges[0].size);
        framebuffer_release(info);
}

static struct fb_ops vesafb_ops = {
        .owner          = THIS_MODULE,
        .fb_destroy     = vesafb_destroy,
        .fb_setcolreg   = vesafb_setcolreg,
        .fb_pan_display = vesafb_pan_display,
        .fb_fillrect    = cfb_fillrect,
        .fb_copyarea    = cfb_copyarea,
        .fb_imageblit   = cfb_imageblit,
};

static int vesafb_setup(char *options)
{
        char *this_opt;
        
        if (!options || !*options)
                return 0;
        
        while ((this_opt = strsep(&options, ",")) != NULL) {
                if (!*this_opt) continue;
                
                if (! strcmp(this_opt, "inverse"))
                        inverse=1;
                else if (! strcmp(this_opt, "redraw"))
                        ypan=0;
                else if (! strcmp(this_opt, "ypan"))
                        ypan=1;
                else if (! strcmp(this_opt, "ywrap"))
                        ypan=2;
                else if (! strcmp(this_opt, "vgapal"))
                        pmi_setpal=0;
                else if (! strcmp(this_opt, "pmipal"))
                        pmi_setpal=1;
                else if (! strncmp(this_opt, "mtrr:", 5))
                        mtrr = simple_strtoul(this_opt+5, NULL, 0);
                else if (! strcmp(this_opt, "nomtrr"))
                        mtrr=0;
                else if (! strncmp(this_opt, "vtotal:", 7))
                        vram_total = simple_strtoul(this_opt+7, NULL, 0);
                else if (! strncmp(this_opt, "vremap:", 7))
                        vram_remap = simple_strtoul(this_opt+7, NULL, 0);
        }
        return 0;
}

static int vesafb_probe(struct platform_device *dev)
{
        struct fb_info *info;
        int i, err;
        unsigned int size_vmode;
        unsigned int size_remap;
        unsigned int size_total;
        char *option = NULL;

        /* ignore error return of fb_get_options */
        fb_get_options("vesafb", &option);
        vesafb_setup(option);

        if (screen_info.orig_video_isVGA != VIDEO_TYPE_VLFB)
                return -ENODEV;

        vga_compat = (screen_info.capabilities & 2) ? 0 : 1;
        vesafb_fix.smem_start = screen_info.lfb_base;
        vesafb_defined.bits_per_pixel = screen_info.lfb_depth;
        if (15 == vesafb_defined.bits_per_pixel)
                vesafb_defined.bits_per_pixel = 16;
        vesafb_defined.xres = screen_info.lfb_width;
        vesafb_defined.yres = screen_info.lfb_height;
        vesafb_fix.line_length = screen_info.lfb_linelength;
        vesafb_fix.visual   = (vesafb_defined.bits_per_pixel == 8) ?
                FB_VISUAL_PSEUDOCOLOR : FB_VISUAL_TRUECOLOR;

        /*   size_vmode -- that is the amount of memory needed for the
         *                 used video mode, i.e. the minimum amount of
         *                 memory we need. */
        size_vmode = vesafb_defined.yres * vesafb_fix.line_length;

        /*   size_total -- all video memory we have. Used for mtrr
         *                 entries, resource allocation and bounds
         *                 checking. */
        size_total = screen_info.lfb_size * 65536;
        if (vram_total)
                size_total = vram_total * 1024 * 1024;
        if (size_total < size_vmode)
                size_total = size_vmode;

        /*   size_remap -- the amount of video memory we are going to
         *                 use for vesafb.  With modern cards it is no
         *                 option to simply use size_total as that
         *                 wastes plenty of kernel address space. */
        size_remap  = size_vmode * 2;
        if (vram_remap)
                size_remap = vram_remap * 1024 * 1024;
        if (size_remap < size_vmode)
                size_remap = size_vmode;
        if (size_remap > size_total)
                size_remap = size_total;
        vesafb_fix.smem_len = size_remap;

#ifndef __i386__
        screen_info.vesapm_seg = 0;
#endif

        if (!request_mem_region(vesafb_fix.smem_start, size_total, "vesafb")) {
                printk(KERN_WARNING
                       "vesafb: cannot reserve video memory at 0x%lx\n",
                        vesafb_fix.smem_start);
                /* We cannot make this fatal. Sometimes this comes from magic
                   spaces our resource handlers simply don't know about */
        }

        info = framebuffer_alloc(sizeof(u32) * 256, &dev->dev);
        if (!info) {
                release_mem_region(vesafb_fix.smem_start, size_total);
                return -ENOMEM;
        }
        info->pseudo_palette = info->par;
        info->par = NULL;

        /* set vesafb aperture size for generic probing */
        info->apertures = alloc_apertures(1);
        if (!info->apertures) {
                err = -ENOMEM;
                goto err;
        }
        info->apertures->ranges[0].base = screen_info.lfb_base;
        info->apertures->ranges[0].size = size_total;

        printk(KERN_INFO "vesafb: mode is %dx%dx%d, linelength=%d, pages=%d\n",
               vesafb_defined.xres, vesafb_defined.yres, vesafb_defined.bits_per_pixel, vesafb_fix.line_length, screen_info.pages);

        if (screen_info.vesapm_seg) {
                printk(KERN_INFO "vesafb: protected mode interface info at %04x:%04x\n",
                       screen_info.vesapm_seg,screen_info.vesapm_off);
        }

        if (screen_info.vesapm_seg < 0xc000)
                ypan = pmi_setpal = 0; /* not available or some DOS TSR ... */

        if (ypan || pmi_setpal) {
                unsigned short *pmi_base;
                pmi_base  = (unsigned short*)phys_to_virt(((unsigned long)screen_info.vesapm_seg << 4) + screen_info.vesapm_off);
                pmi_start = (void*)((char*)pmi_base + pmi_base[1]);
                pmi_pal   = (void*)((char*)pmi_base + pmi_base[2]);
                printk(KERN_INFO "vesafb: pmi: set display start = %p, set palette = %p\n",pmi_start,pmi_pal);
                if (pmi_base[3]) {
                        printk(KERN_INFO "vesafb: pmi: ports = ");
                                for (i = pmi_base[3]/2; pmi_base[i] != 0xffff; i++)
                                        printk("%x ",pmi_base[i]);
                        printk("\n");
                        if (pmi_base[i] != 0xffff) {
                                /*
                                 * memory areas not supported (yet?)
                                 *
                                 * Rules are: we have to set up a descriptor for the requested
                                 * memory area and pass it in the ES register to the BIOS function.
                                 */
                                printk(KERN_INFO "vesafb: can't handle memory requests, pmi disabled\n");
                                ypan = pmi_setpal = 0;
                        }
                }
        }

        if (vesafb_defined.bits_per_pixel == 8 && !pmi_setpal && !vga_compat) {
                printk(KERN_WARNING "vesafb: hardware palette is unchangeable,\n"
                                    "        colors may be incorrect\n");
                vesafb_fix.visual = FB_VISUAL_STATIC_PSEUDOCOLOR;
        }

        vesafb_defined.xres_virtual = vesafb_defined.xres;
        vesafb_defined.yres_virtual = vesafb_fix.smem_len / vesafb_fix.line_length;
        if (ypan && vesafb_defined.yres_virtual > vesafb_defined.yres) {
                printk(KERN_INFO "vesafb: scrolling: %s using protected mode interface, yres_virtual=%d\n",
                       (ypan > 1) ? "ywrap" : "ypan",vesafb_defined.yres_virtual);
        } else {
                printk(KERN_INFO "vesafb: scrolling: redraw\n");
                vesafb_defined.yres_virtual = vesafb_defined.yres;
                ypan = 0;
        }

        /* some dummy values for timing to make fbset happy */
        vesafb_defined.pixclock     = 10000000 / vesafb_defined.xres * 1000 / vesafb_defined.yres;
        vesafb_defined.left_margin  = (vesafb_defined.xres / 8) & 0xf8;
        vesafb_defined.hsync_len    = (vesafb_defined.xres / 8) & 0xf8;
        
        vesafb_defined.red.offset    = screen_info.red_pos;
        vesafb_defined.red.length    = screen_info.red_size;
        vesafb_defined.green.offset  = screen_info.green_pos;
        vesafb_defined.green.length  = screen_info.green_size;
        vesafb_defined.blue.offset   = screen_info.blue_pos;
        vesafb_defined.blue.length   = screen_info.blue_size;
        vesafb_defined.transp.offset = screen_info.rsvd_pos;
        vesafb_defined.transp.length = screen_info.rsvd_size;

        if (vesafb_defined.bits_per_pixel <= 8) {
                depth = vesafb_defined.green.length;
                vesafb_defined.red.length =
                vesafb_defined.green.length =
                vesafb_defined.blue.length =
                vesafb_defined.bits_per_pixel;
        }

        printk(KERN_INFO "vesafb: %s: "
               "size=%d:%d:%d:%d, shift=%d:%d:%d:%d\n",
               (vesafb_defined.bits_per_pixel > 8) ?
               "Truecolor" : (vga_compat || pmi_setpal) ?
               "Pseudocolor" : "Static Pseudocolor",
               screen_info.rsvd_size,
               screen_info.red_size,
               screen_info.green_size,
               screen_info.blue_size,
               screen_info.rsvd_pos,
               screen_info.red_pos,
               screen_info.green_pos,
               screen_info.blue_pos);

        vesafb_fix.ypanstep  = ypan     ? 1 : 0;
        vesafb_fix.ywrapstep = (ypan>1) ? 1 : 0;

        /* request failure does not faze us, as vgacon probably has this
         * region already (FIXME) */
        request_region(0x3c0, 32, "vesafb");

#ifdef CONFIG_MTRR
        if (mtrr) {
                unsigned int temp_size = size_total;
                unsigned int type = 0;

                switch (mtrr) {
                case 1:
                        type = MTRR_TYPE_UNCACHABLE;
                        break;
                case 2:
                        type = MTRR_TYPE_WRBACK;
                        break;
                case 3:
                        type = MTRR_TYPE_WRCOMB;
                        break;
                case 4:
                        type = MTRR_TYPE_WRTHROUGH;
                        break;
                default:
                        type = 0;
                        break;
                }

                if (type) {
                        int rc;

                        /* Find the largest power-of-two */
                        temp_size = roundup_pow_of_two(temp_size);

                        /* Try and find a power of two to add */
                        do {
                                rc = mtrr_add(vesafb_fix.smem_start, temp_size,
                                              type, 1);
                                temp_size >>= 1;
                        } while (temp_size >= PAGE_SIZE && rc == -EINVAL);
                }
        }
#endif
        
        switch (mtrr) {
        case 1: /* uncachable */
                info->screen_base = ioremap_nocache(vesafb_fix.smem_start, vesafb_fix.smem_len);
                break;
        case 2: /* write-back */
                info->screen_base = ioremap_cache(vesafb_fix.smem_start, vesafb_fix.smem_len);
                break;
        case 3: /* write-combining */
                info->screen_base = ioremap_wc(vesafb_fix.smem_start, vesafb_fix.smem_len);
                break;
        case 4: /* write-through */
        default:
                info->screen_base = ioremap(vesafb_fix.smem_start, vesafb_fix.smem_len);
                break;
        }
        if (!info->screen_base) {
                printk(KERN_ERR
                       "vesafb: abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
                        vesafb_fix.smem_len, vesafb_fix.smem_start);
                err = -EIO;
                goto err;
        }

        printk(KERN_INFO "vesafb: framebuffer at 0x%lx, mapped to 0x%p, "
               "using %dk, total %dk\n",
               vesafb_fix.smem_start, info->screen_base,
               size_remap/1024, size_total/1024);

        info->fbops = &vesafb_ops;
        info->var = vesafb_defined;
        info->fix = vesafb_fix;
        info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE |
                (ypan ? FBINFO_HWACCEL_YPAN : 0);

        if (!ypan)
                info->fbops->fb_pan_display = NULL;

        if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
                err = -ENOMEM;
                goto err;
        }
        if (register_framebuffer(info)<0) {
                err = -EINVAL;
                fb_dealloc_cmap(&info->cmap);
                goto err;
        }
        fb_info(info, "%s frame buffer device\n", info->fix.id);
        return 0;
err:
        if (info->screen_base)
                iounmap(info->screen_base);
        framebuffer_release(info);
        release_mem_region(vesafb_fix.smem_start, size_total);
        return err;
}

static struct platform_driver vesafb_driver = {
        .driver = {
                .name = "vesa-framebuffer",
                .owner = THIS_MODULE,
        },
        .probe = vesafb_probe,
};

module_platform_driver(vesafb_driver);
MODULE_LICENSE("GPL");