// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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/aperture.h>
#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/sysfb.h>
#include <linux/io.h>

#include <video/vga.h>

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

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

struct vesafb_par {
        u32 pseudo_palette[256];
        resource_size_t base;
        resource_size_t size;
        int wc_cookie;
        struct resource *region;
};

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;
}

/*
 * fb_ops.fb_destroy is called by the last put_fb_info() call at the end
 * of unregister_framebuffer() or fb_release(). Do any cleanup here.
 */
static void vesafb_destroy(struct fb_info *info)
{
        struct vesafb_par *par = info->par;

        fb_dealloc_cmap(&info->cmap);
        arch_phys_wc_del(par->wc_cookie);
        if (info->screen_base)
                iounmap(info->screen_base);
        release_mem_region(par->base, par->size);

        framebuffer_release(info);
}

static struct fb_ops vesafb_ops = {
        .owner          = THIS_MODULE,
        FB_DEFAULT_IOMEM_OPS,
        .fb_destroy     = vesafb_destroy,
        .fb_setcolreg   = vesafb_setcolreg,
        .fb_pan_display = vesafb_pan_display,
};

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 sysfb_display_info *dpy;
        struct screen_info *si;
        struct fb_info *info;
        struct vesafb_par *par;
        int i, err;
        unsigned int size_vmode;
        unsigned int size_remap;
        unsigned int size_total;
        char *option = NULL;

        /*
         * If we fail probing the device, the kernel might try a different
         * driver. We get a copy of the attached screen_info, so that we can
         * modify its values without affecting later drivers.
         */
        dpy = dev_get_platdata(&dev->dev);
        if (!dpy)
                return -ENODEV;

        si = devm_kmemdup(&dev->dev, &dpy->screen, sizeof(*si), GFP_KERNEL);
        if (!si)
                return -ENOMEM;

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

        if (si->orig_video_isVGA != VIDEO_TYPE_VLFB)
                return -ENODEV;

        vga_compat = !__screen_info_vbe_mode_nonvga(si);
        vesafb_fix.smem_start = si->lfb_base;
        vesafb_defined.bits_per_pixel = si->lfb_depth;
        if (15 == vesafb_defined.bits_per_pixel)
                vesafb_defined.bits_per_pixel = 16;
        vesafb_defined.xres = si->lfb_width;
        vesafb_defined.yres = si->lfb_height;
        vesafb_fix.line_length = si->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 = si->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__
        si->vesapm_seg = 0;
#endif

        if (!request_mem_region(vesafb_fix.smem_start, size_total, "vesafb")) {
                dev_warn(&dev->dev,
                       "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(struct vesafb_par), &dev->dev);
        if (!info) {
                release_mem_region(vesafb_fix.smem_start, size_total);
                return -ENOMEM;
        }
        platform_set_drvdata(dev, info);
        par = info->par;
        info->pseudo_palette = par->pseudo_palette;

        par->base = si->lfb_base;
        par->size = size_total;

        dev_info(&dev->dev, "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, si->pages);

        if (si->vesapm_seg) {
                dev_info(&dev->dev, "protected mode interface info at %04x:%04x\n",
                       si->vesapm_seg, si->vesapm_off);
        }

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

        if (ypan || pmi_setpal) {
                unsigned long pmi_phys;
                unsigned short *pmi_base;
                pmi_phys  = ((unsigned long)si->vesapm_seg << 4) + si->vesapm_off;
                pmi_base  = (unsigned short *)phys_to_virt(pmi_phys);
                pmi_start = (void*)((char*)pmi_base + pmi_base[1]);
                pmi_pal   = (void*)((char*)pmi_base + pmi_base[2]);
                dev_info(&dev->dev, "pmi: set display start = %p, set palette = %p\n",
                         pmi_start, pmi_pal);
                if (pmi_base[3]) {
                        dev_info(&dev->dev, "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.
                                 */
                                dev_info(&dev->dev, "can't handle memory requests, pmi disabled\n");
                                ypan = pmi_setpal = 0;
                        }
                }
        }

        if (vesafb_defined.bits_per_pixel == 8 && !pmi_setpal && !vga_compat) {
                dev_warn(&dev->dev, "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) {
                dev_info(&dev->dev, "scrolling: %s using protected mode interface, yres_virtual=%d\n",
                       (ypan > 1) ? "ywrap" : "ypan",vesafb_defined.yres_virtual);
        } else {
                dev_info(&dev->dev, "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    = si->red_pos;
        vesafb_defined.red.length    = si->red_size;
        vesafb_defined.green.offset  = si->green_pos;
        vesafb_defined.green.length  = si->green_size;
        vesafb_defined.blue.offset   = si->blue_pos;
        vesafb_defined.blue.length   = si->blue_size;
        vesafb_defined.transp.offset = si->rsvd_pos;
        vesafb_defined.transp.length = si->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;
        }

        dev_info(&dev->dev, "%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",
               si->rsvd_size,
               si->red_size,
               si->green_size,
               si->blue_size,
               si->rsvd_pos,
               si->red_pos,
               si->green_pos,
               si->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) */
        par->region = request_region(0x3c0, 32, "vesafb");

        if (mtrr == 3) {
                unsigned int temp_size = size_total;

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

                /* Try and find a power of two to add */
                do {
                        par->wc_cookie =
                                arch_phys_wc_add(vesafb_fix.smem_start,
                                                 temp_size);
                        temp_size >>= 1;
                } while (temp_size >= PAGE_SIZE && par->wc_cookie < 0);

                info->screen_base = ioremap_wc(vesafb_fix.smem_start, vesafb_fix.smem_len);
        } else {
                if (mtrr && mtrr != 3)
                        WARN_ONCE(1, "Only MTRR_TYPE_WRCOMB (3) make sense\n");
                info->screen_base = ioremap(vesafb_fix.smem_start, vesafb_fix.smem_len);
        }

        if (!info->screen_base) {
                dev_err(&dev->dev,
                       "abort, cannot ioremap video memory 0x%x @ 0x%lx\n",
                        vesafb_fix.smem_len, vesafb_fix.smem_start);
                err = -EIO;
                goto err_release_region;
        }

        dev_info(&dev->dev, "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);

        if (!ypan)
                vesafb_ops.fb_pan_display = NULL;

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

        if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
                err = -ENOMEM;
                goto err_release_region;
        }
        err = devm_aperture_acquire_for_platform_device(dev, par->base, par->size);
        if (err)
                goto err_fb_dealloc_cmap;
        if (register_framebuffer(info)<0) {
                err = -EINVAL;
                goto err_fb_dealloc_cmap;
        }
        fb_info(info, "%s frame buffer device\n", info->fix.id);
        return 0;
err_fb_dealloc_cmap:
        fb_dealloc_cmap(&info->cmap);
err_release_region:
        arch_phys_wc_del(par->wc_cookie);
        if (info->screen_base)
                iounmap(info->screen_base);
        if (par->region)
                release_region(0x3c0, 32);
        framebuffer_release(info);
        release_mem_region(vesafb_fix.smem_start, size_total);
        return err;
}

static void vesafb_remove(struct platform_device *pdev)
{
        struct fb_info *info = platform_get_drvdata(pdev);

        if (((struct vesafb_par *)(info->par))->region)
                release_region(0x3c0, 32);

        /* vesafb_destroy takes care of info cleanup */
        unregister_framebuffer(info);
}

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

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