/*
 * drivers/video/pvr2fb.c
 *
 * Frame buffer and fbcon support for the NEC PowerVR2 found within the Sega
 * Dreamcast.
 *
 * Copyright (c) 2001 M. R. Brown <mrbrown@0xd6.org>
 * Copyright (c) 2001 - 2008  Paul Mundt <lethal@linux-sh.org>
 *
 * This driver is mostly based on the excellent amifb and vfb sources.  It uses
 * an odd scheme for converting hardware values to/from framebuffer values,
 * here are some hacked-up formulas:
 *
 *  The Dreamcast has screen offsets from each side of its four borders and
 *  the start offsets of the display window.  I used these values to calculate
 *  'pseudo' values (think of them as placeholders) for the fb video mode, so
 *  that when it came time to convert these values back into their hardware
 *  values, I could just add mode- specific offsets to get the correct mode
 *  settings:
 *
 *      left_margin = diwstart_h - borderstart_h;
 *      right_margin = borderstop_h - (diwstart_h + xres);
 *      upper_margin = diwstart_v - borderstart_v;
 *      lower_margin = borderstop_v - (diwstart_h + yres);
 *
 *      hsync_len = borderstart_h + (hsync_total - borderstop_h);
 *      vsync_len = borderstart_v + (vsync_total - borderstop_v);
 *
 *  Then, when it's time to convert back to hardware settings, the only
 *  constants are the borderstart_* offsets, all other values are derived from
 *  the fb video mode:
 *
 *      // PAL
 *      borderstart_h = 116;
 *      borderstart_v = 44;
 *      ...
 *      borderstop_h = borderstart_h + hsync_total - hsync_len;
 *      ...
 *      diwstart_v = borderstart_v - upper_margin;
 *
 *  However, in the current implementation, the borderstart values haven't had
 *  the benefit of being fully researched, so some modes may be broken.
 */

#undef DEBUG

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/fb.h>
#include <linux/init.h>
#include <linux/pci.h>

#ifdef CONFIG_SH_DREAMCAST
#include <asm/machvec.h>
#include <mach-dreamcast/mach/sysasic.h>
#endif

#ifdef CONFIG_PVR2_DMA
#include <linux/pagemap.h>
#include <mach/dma.h>
#include <asm/dma.h>
#endif

#ifdef CONFIG_SH_STORE_QUEUES
#include <linux/uaccess.h>
#include <cpu/sq.h>
#endif

#ifndef PCI_DEVICE_ID_NEC_NEON250
#  define PCI_DEVICE_ID_NEC_NEON250     0x0067
#endif

/* 2D video registers */
#define DISP_BASE       par->mmio_base
#define DISP_BRDRCOLR (DISP_BASE + 0x40)
#define DISP_DIWMODE (DISP_BASE + 0x44)
#define DISP_DIWADDRL (DISP_BASE + 0x50)
#define DISP_DIWADDRS (DISP_BASE + 0x54)
#define DISP_DIWSIZE (DISP_BASE + 0x5c)
#define DISP_SYNCCONF (DISP_BASE + 0xd0)
#define DISP_BRDRHORZ (DISP_BASE + 0xd4)
#define DISP_SYNCSIZE (DISP_BASE + 0xd8)
#define DISP_BRDRVERT (DISP_BASE + 0xdc)
#define DISP_DIWCONF (DISP_BASE + 0xe8)
#define DISP_DIWHSTRT (DISP_BASE + 0xec)
#define DISP_DIWVSTRT (DISP_BASE + 0xf0)
#define DISP_PIXDEPTH (DISP_BASE + 0x108)

/* Pixel clocks, one for TV output, doubled for VGA output */
#define TV_CLK 74239
#define VGA_CLK 37119

/* This is for 60Hz - the VTOTAL is doubled for interlaced modes */
#define PAL_HTOTAL 863
#define PAL_VTOTAL 312
#define NTSC_HTOTAL 857
#define NTSC_VTOTAL 262

/* Supported cable types */
enum { CT_VGA, CT_NONE, CT_RGB, CT_COMPOSITE };

/* Supported video output types */
enum { VO_PAL, VO_NTSC, VO_VGA };

/* Supported palette types */
enum { PAL_ARGB1555, PAL_RGB565, PAL_ARGB4444, PAL_ARGB8888 };

struct pvr2_params { unsigned int val; char *name; };
static struct pvr2_params cables[] = {
        { CT_VGA, "VGA" }, { CT_RGB, "RGB" }, { CT_COMPOSITE, "COMPOSITE" },
};

static struct pvr2_params outputs[] = {
        { VO_PAL, "PAL" }, { VO_NTSC, "NTSC" }, { VO_VGA, "VGA" },
};

/*
 * This describes the current video mode
 */

static struct pvr2fb_par {
        unsigned int hsync_total;       /* Clocks/line */
        unsigned int vsync_total;       /* Lines/field */
        unsigned int borderstart_h;
        unsigned int borderstop_h;
        unsigned int borderstart_v;
        unsigned int borderstop_v;
        unsigned int diwstart_h;        /* Horizontal offset of the display field */
        unsigned int diwstart_v;        /* Vertical offset of the display field, for
                                   interlaced modes, this is the long field */
        unsigned long disp_start;       /* Address of image within VRAM */
        unsigned char is_interlaced;    /* Is the display interlaced? */
        unsigned char is_doublescan;    /* Are scanlines output twice? (doublescan) */
        unsigned char is_lowres;        /* Is horizontal pixel-doubling enabled? */

        unsigned long mmio_base;        /* MMIO base */
        u32 palette[16];
} *currentpar;

static struct fb_info *fb_info;

static struct fb_fix_screeninfo pvr2_fix = {
        .id =           "NEC PowerVR2",
        .type =         FB_TYPE_PACKED_PIXELS,
        .visual =       FB_VISUAL_TRUECOLOR,
        .ypanstep =     1,
        .ywrapstep =    1,
        .accel =        FB_ACCEL_NONE,
};

static struct fb_var_screeninfo pvr2_var = {
        .xres =         640,
        .yres =         480,
        .xres_virtual = 640,
        .yres_virtual = 480,
        .bits_per_pixel =16,
        .red =          { 11, 5, 0 },
        .green =        {  5, 6, 0 },
        .blue =         {  0, 5, 0 },
        .activate =     FB_ACTIVATE_NOW,
        .height =       -1,
        .width =        -1,
        .vmode =        FB_VMODE_NONINTERLACED,
};

static int cable_type = CT_VGA;
static int video_output = VO_VGA;

static int nopan = 0;
static int nowrap = 1;

/*
 * We do all updating, blanking, etc. during the vertical retrace period
 */
static unsigned int do_vmode_full = 0;  /* Change the video mode */
static unsigned int do_vmode_pan = 0;   /* Update the video mode */
static short do_blank = 0;              /* (Un)Blank the screen */

static unsigned int is_blanked = 0;             /* Is the screen blanked? */

#ifdef CONFIG_SH_STORE_QUEUES
static unsigned long pvr2fb_map;
#endif

#ifdef CONFIG_PVR2_DMA
static unsigned int shdma = PVR2_CASCADE_CHAN;
static unsigned int pvr2dma = ONCHIP_NR_DMA_CHANNELS;
#endif

static int pvr2fb_setcolreg(unsigned int regno, unsigned int red, unsigned int green, unsigned int blue,
                            unsigned int transp, struct fb_info *info);
static int pvr2fb_blank(int blank, struct fb_info *info);
static unsigned long get_line_length(int xres_virtual, int bpp);
static void set_color_bitfields(struct fb_var_screeninfo *var);
static int pvr2fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info);
static int pvr2fb_set_par(struct fb_info *info);
static void pvr2_update_display(struct fb_info *info);
static void pvr2_init_display(struct fb_info *info);
static void pvr2_do_blank(void);
static irqreturn_t pvr2fb_interrupt(int irq, void *dev_id);
static int pvr2_init_cable(void);
static int pvr2_get_param(const struct pvr2_params *p, const char *s,
                            int val, int size);
#ifdef CONFIG_PVR2_DMA
static ssize_t pvr2fb_write(struct fb_info *info, const char *buf,
                            size_t count, loff_t *ppos);
#endif

static struct fb_ops pvr2fb_ops = {
        .owner          = THIS_MODULE,
        .fb_setcolreg   = pvr2fb_setcolreg,
        .fb_blank       = pvr2fb_blank,
        .fb_check_var   = pvr2fb_check_var,
        .fb_set_par     = pvr2fb_set_par,
#ifdef CONFIG_PVR2_DMA
        .fb_write       = pvr2fb_write,
#endif
        .fb_fillrect    = cfb_fillrect,
        .fb_copyarea    = cfb_copyarea,
        .fb_imageblit   = cfb_imageblit,
};

static struct fb_videomode pvr2_modedb[] = {
    /*
     * Broadcast video modes (PAL and NTSC).  I'm unfamiliar with
     * PAL-M and PAL-N, but from what I've read both modes parallel PAL and
     * NTSC, so it shouldn't be a problem (I hope).
     */

    {
        /* 640x480 @ 60Hz interlaced (NTSC) */
        "ntsc_640x480i", 60, 640, 480, TV_CLK, 38, 33, 0, 18, 146, 26,
        FB_SYNC_BROADCAST, FB_VMODE_INTERLACED | FB_VMODE_YWRAP
    }, {
        /* 640x240 @ 60Hz (NTSC) */
        /* XXX: Broken! Don't use... */
        "ntsc_640x240", 60, 640, 240, TV_CLK, 38, 33, 0, 0, 146, 22,
        FB_SYNC_BROADCAST, FB_VMODE_YWRAP
    }, {
        /* 640x480 @ 60hz (VGA) */
        "vga_640x480", 60, 640, 480, VGA_CLK, 38, 33, 0, 18, 146, 26,
        0, FB_VMODE_YWRAP
    },
};

#define NUM_TOTAL_MODES  ARRAY_SIZE(pvr2_modedb)

#define DEFMODE_NTSC    0
#define DEFMODE_PAL     0
#define DEFMODE_VGA     2

static int defmode = DEFMODE_NTSC;
static char *mode_option = NULL;

static inline void pvr2fb_set_pal_type(unsigned int type)
{
        struct pvr2fb_par *par = (struct pvr2fb_par *)fb_info->par;

        fb_writel(type, par->mmio_base + 0x108);
}

static inline void pvr2fb_set_pal_entry(struct pvr2fb_par *par,
                                        unsigned int regno,
                                        unsigned int val)
{
        fb_writel(val, par->mmio_base + 0x1000 + (4 * regno));
}

static int pvr2fb_blank(int blank, struct fb_info *info)
{
        do_blank = blank ? blank : -1;
        return 0;
}

static inline unsigned long get_line_length(int xres_virtual, int bpp)
{
        return (unsigned long)((((xres_virtual*bpp)+31)&~31) >> 3);
}

static void set_color_bitfields(struct fb_var_screeninfo *var)
{
        switch (var->bits_per_pixel) {
            case 16:        /* RGB 565 */
                pvr2fb_set_pal_type(PAL_RGB565);
                var->red.offset = 11;    var->red.length = 5;
                var->green.offset = 5;   var->green.length = 6;
                var->blue.offset = 0;    var->blue.length = 5;
                var->transp.offset = 0;  var->transp.length = 0;
                break;
            case 24:        /* RGB 888 */
                var->red.offset = 16;    var->red.length = 8;
                var->green.offset = 8;   var->green.length = 8;
                var->blue.offset = 0;    var->blue.length = 8;
                var->transp.offset = 0;  var->transp.length = 0;
                break;
            case 32:        /* ARGB 8888 */
                pvr2fb_set_pal_type(PAL_ARGB8888);
                var->red.offset = 16;    var->red.length = 8;
                var->green.offset = 8;   var->green.length = 8;
                var->blue.offset = 0;    var->blue.length = 8;
                var->transp.offset = 24; var->transp.length = 8;
                break;
        }
}

static int pvr2fb_setcolreg(unsigned int regno, unsigned int red,
                            unsigned int green, unsigned int blue,
                            unsigned int transp, struct fb_info *info)
{
        struct pvr2fb_par *par = (struct pvr2fb_par *)info->par;
        unsigned int tmp;

        if (regno > info->cmap.len)
                return 1;

        /*
         * We only support the hardware palette for 16 and 32bpp. It's also
         * expected that the palette format has been set by the time we get
         * here, so we don't waste time setting it again.
         */
        switch (info->var.bits_per_pixel) {
            case 16: /* RGB 565 */
                tmp =  (red   & 0xf800)       |
                      ((green & 0xfc00) >> 5) |
                      ((blue  & 0xf800) >> 11);

                pvr2fb_set_pal_entry(par, regno, tmp);
                break;
            case 24: /* RGB 888 */
                red >>= 8; green >>= 8; blue >>= 8;
                tmp = (red << 16) | (green << 8) | blue;
                break;
            case 32: /* ARGB 8888 */
                red >>= 8; green >>= 8; blue >>= 8;
                tmp = (transp << 24) | (red << 16) | (green << 8) | blue;

                pvr2fb_set_pal_entry(par, regno, tmp);
                break;
            default:
                pr_debug("Invalid bit depth %d?!?\n", info->var.bits_per_pixel);
                return 1;
        }

        if (regno < 16)
                ((u32*)(info->pseudo_palette))[regno] = tmp;

        return 0;
}

static int pvr2fb_set_par(struct fb_info *info)
{
        struct pvr2fb_par *par = (struct pvr2fb_par *)info->par;
        struct fb_var_screeninfo *var = &info->var;
        unsigned long line_length;
        unsigned int vtotal;

        /*
         * XXX: It's possible that a user could use a VGA box, change the cable
         * type in hardware (i.e. switch from VGA<->composite), then change
         * modes (i.e. switching to another VT).  If that happens we should
         * automagically change the output format to cope, but currently I
         * don't have a VGA box to make sure this works properly.
         */
        cable_type = pvr2_init_cable();
        if (cable_type == CT_VGA && video_output != VO_VGA)
                video_output = VO_VGA;

        var->vmode &= FB_VMODE_MASK;
        if (var->vmode & FB_VMODE_INTERLACED && video_output != VO_VGA)
                par->is_interlaced = 1;
        /*
         * XXX: Need to be more creative with this (i.e. allow doublecan for
         * PAL/NTSC output).
         */
        if (var->vmode & FB_VMODE_DOUBLE && video_output == VO_VGA)
                par->is_doublescan = 1;

        par->hsync_total = var->left_margin + var->xres + var->right_margin +
                           var->hsync_len;
        par->vsync_total = var->upper_margin + var->yres + var->lower_margin +
                           var->vsync_len;

        if (var->sync & FB_SYNC_BROADCAST) {
                vtotal = par->vsync_total;
                if (par->is_interlaced)
                        vtotal /= 2;
                if (vtotal > (PAL_VTOTAL + NTSC_VTOTAL)/2) {
                        /* XXX: Check for start values here... */
                        /* XXX: Check hardware for PAL-compatibility */
                        par->borderstart_h = 116;
                        par->borderstart_v = 44;
                } else {
                        /* NTSC video output */
                        par->borderstart_h = 126;
                        par->borderstart_v = 18;
                }
        } else {
                /* VGA mode */
                /* XXX: What else needs to be checked? */
                /*
                 * XXX: We have a little freedom in VGA modes, what ranges
                 * should be here (i.e. hsync/vsync totals, etc.)?
                 */
                par->borderstart_h = 126;
                par->borderstart_v = 40;
        }

        /* Calculate the remainding offsets */
        par->diwstart_h = par->borderstart_h + var->left_margin;
        par->diwstart_v = par->borderstart_v + var->upper_margin;
        par->borderstop_h = par->diwstart_h + var->xres +
                            var->right_margin;
        par->borderstop_v = par->diwstart_v + var->yres +
                            var->lower_margin;

        if (!par->is_interlaced)
                par->borderstop_v /= 2;
        if (info->var.xres < 640)
                par->is_lowres = 1;

        line_length = get_line_length(var->xres_virtual, var->bits_per_pixel);
        par->disp_start = info->fix.smem_start + (line_length * var->yoffset) * line_length;
        info->fix.line_length = line_length;
        return 0;
}

static int pvr2fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
        struct pvr2fb_par *par = (struct pvr2fb_par *)info->par;
        unsigned int vtotal, hsync_total;
        unsigned long line_length;

        if (var->pixclock != TV_CLK && var->pixclock != VGA_CLK) {
                pr_debug("Invalid pixclock value %d\n", var->pixclock);
                return -EINVAL;
        }

        if (var->xres < 320)
                var->xres = 320;
        if (var->yres < 240)
                var->yres = 240;
        if (var->xres_virtual < var->xres)
                var->xres_virtual = var->xres;
        if (var->yres_virtual < var->yres)
                var->yres_virtual = var->yres;

        if (var->bits_per_pixel <= 16)
                var->bits_per_pixel = 16;
        else if (var->bits_per_pixel <= 24)
                var->bits_per_pixel = 24;
        else if (var->bits_per_pixel <= 32)
                var->bits_per_pixel = 32;

        set_color_bitfields(var);

        if (var->vmode & FB_VMODE_YWRAP) {
                if (var->xoffset || var->yoffset < 0 ||
                    var->yoffset >= var->yres_virtual) {
                        var->xoffset = var->yoffset = 0;
                } else {
                        if (var->xoffset > var->xres_virtual - var->xres ||
                            var->yoffset > var->yres_virtual - var->yres ||
                            var->xoffset < 0 || var->yoffset < 0)
                                var->xoffset = var->yoffset = 0;
                }
        } else {
                var->xoffset = var->yoffset = 0;
        }

        /*
         * XXX: Need to be more creative with this (i.e. allow doublecan for
         * PAL/NTSC output).
         */
        if (var->yres < 480 && video_output == VO_VGA)
                var->vmode |= FB_VMODE_DOUBLE;

        if (video_output != VO_VGA) {
                var->sync |= FB_SYNC_BROADCAST;
                var->vmode |= FB_VMODE_INTERLACED;
        } else {
                var->sync &= ~FB_SYNC_BROADCAST;
                var->vmode &= ~FB_VMODE_INTERLACED;
                var->vmode |= FB_VMODE_NONINTERLACED;
        }

        if ((var->activate & FB_ACTIVATE_MASK) != FB_ACTIVATE_TEST) {
                var->right_margin = par->borderstop_h -
                                   (par->diwstart_h + var->xres);
                var->left_margin  = par->diwstart_h - par->borderstart_h;
                var->hsync_len    = par->borderstart_h +
                                   (par->hsync_total - par->borderstop_h);

                var->upper_margin = par->diwstart_v - par->borderstart_v;
                var->lower_margin = par->borderstop_v -
                                   (par->diwstart_v + var->yres);
                var->vsync_len    = par->borderstop_v +
                                   (par->vsync_total - par->borderstop_v);
        }

        hsync_total = var->left_margin + var->xres + var->right_margin +
                      var->hsync_len;
        vtotal = var->upper_margin + var->yres + var->lower_margin +
                 var->vsync_len;

        if (var->sync & FB_SYNC_BROADCAST) {
                if (var->vmode & FB_VMODE_INTERLACED)
                        vtotal /= 2;
                if (vtotal > (PAL_VTOTAL + NTSC_VTOTAL)/2) {
                        /* PAL video output */
                        /* XXX: Should be using a range here ... ? */
                        if (hsync_total != PAL_HTOTAL) {
                                pr_debug("invalid hsync total for PAL\n");
                                return -EINVAL;
                        }
                } else {
                        /* NTSC video output */
                        if (hsync_total != NTSC_HTOTAL) {
                                pr_debug("invalid hsync total for NTSC\n");
                                return -EINVAL;
                        }
                }
        }

        /* Check memory sizes */
        line_length = get_line_length(var->xres_virtual, var->bits_per_pixel);
        if (line_length * var->yres_virtual > info->fix.smem_len)
                return -ENOMEM;

        return 0;
}

static void pvr2_update_display(struct fb_info *info)
{
        struct pvr2fb_par *par = (struct pvr2fb_par *) info->par;
        struct fb_var_screeninfo *var = &info->var;

        /* Update the start address of the display image */
        fb_writel(par->disp_start, DISP_DIWADDRL);
        fb_writel(par->disp_start +
                  get_line_length(var->xoffset+var->xres, var->bits_per_pixel),
                  DISP_DIWADDRS);
}

/*
 * Initialize the video mode.  Currently, the 16bpp and 24bpp modes aren't
 * very stable.  It's probably due to the fact that a lot of the 2D video
 * registers are still undocumented.
 */

static void pvr2_init_display(struct fb_info *info)
{
        struct pvr2fb_par *par = (struct pvr2fb_par *) info->par;
        struct fb_var_screeninfo *var = &info->var;
        unsigned int diw_height, diw_width, diw_modulo = 1;
        unsigned int bytesperpixel = var->bits_per_pixel >> 3;

        /* hsync and vsync totals */
        fb_writel((par->vsync_total << 16) | par->hsync_total, DISP_SYNCSIZE);

        /* column height, modulo, row width */
        /* since we're "panning" within vram, we need to offset things based
         * on the offset from the virtual x start to our real gfx. */
        if (video_output != VO_VGA && par->is_interlaced)
                diw_modulo += info->fix.line_length / 4;
        diw_height = (par->is_interlaced ? var->yres / 2 : var->yres);
        diw_width = get_line_length(var->xres, var->bits_per_pixel) / 4;
        fb_writel((diw_modulo << 20) | (--diw_height << 10) | --diw_width,
                  DISP_DIWSIZE);

        /* display address, long and short fields */
        fb_writel(par->disp_start, DISP_DIWADDRL);
        fb_writel(par->disp_start +
                  get_line_length(var->xoffset+var->xres, var->bits_per_pixel),
                  DISP_DIWADDRS);

        /* border horizontal, border vertical, border color */
        fb_writel((par->borderstart_h << 16) | par->borderstop_h, DISP_BRDRHORZ);
        fb_writel((par->borderstart_v << 16) | par->borderstop_v, DISP_BRDRVERT);
        fb_writel(0, DISP_BRDRCOLR);

        /* display window start position */
        fb_writel(par->diwstart_h, DISP_DIWHSTRT);
        fb_writel((par->diwstart_v << 16) | par->diwstart_v, DISP_DIWVSTRT);

        /* misc. settings */
        fb_writel((0x16 << 16) | par->is_lowres, DISP_DIWCONF);

        /* clock doubler (for VGA), scan doubler, display enable */
        fb_writel(((video_output == VO_VGA) << 23) |
                  (par->is_doublescan << 1) | 1, DISP_DIWMODE);

        /* bits per pixel */
        fb_writel(fb_readl(DISP_DIWMODE) | (--bytesperpixel << 2), DISP_DIWMODE);
        fb_writel(bytesperpixel << 2, DISP_PIXDEPTH);

        /* video enable, color sync, interlace,
         * hsync and vsync polarity (currently unused) */
        fb_writel(0x100 | ((par->is_interlaced /*|4*/) << 4), DISP_SYNCCONF);
}

/* Simulate blanking by making the border cover the entire screen */

#define BLANK_BIT (1<<3)

static void pvr2_do_blank(void)
{
        struct pvr2fb_par *par = currentpar;
        unsigned long diwconf;

        diwconf = fb_readl(DISP_DIWCONF);
        if (do_blank > 0)
                fb_writel(diwconf | BLANK_BIT, DISP_DIWCONF);
        else
                fb_writel(diwconf & ~BLANK_BIT, DISP_DIWCONF);

        is_blanked = do_blank > 0 ? do_blank : 0;
}

static irqreturn_t pvr2fb_interrupt(int irq, void *dev_id)
{
        struct fb_info *info = dev_id;

        if (do_vmode_pan || do_vmode_full)
                pvr2_update_display(info);
        if (do_vmode_full)
                pvr2_init_display(info);
        if (do_vmode_pan)
                do_vmode_pan = 0;
        if (do_vmode_full)
                do_vmode_full = 0;
        if (do_blank) {
                pvr2_do_blank();
                do_blank = 0;
        }
        return IRQ_HANDLED;
}

/*
 * Determine the cable type and initialize the cable output format.  Don't do
 * anything if the cable type has been overidden (via "cable:XX").
 */

#define PCTRA 0xff80002c
#define PDTRA 0xff800030
#define VOUTC 0xa0702c00

static int pvr2_init_cable(void)
{
        if (cable_type < 0) {
                fb_writel((fb_readl(PCTRA) & 0xfff0ffff) | 0x000a0000,
                          PCTRA);
                cable_type = (fb_readw(PDTRA) >> 8) & 3;
        }

        /* Now select the output format (either composite or other) */
        /* XXX: Save the previous val first, as this reg is also AICA
          related */
        if (cable_type == CT_COMPOSITE)
                fb_writel(3 << 8, VOUTC);
        else if (cable_type == CT_RGB)
                fb_writel(1 << 9, VOUTC);
        else
                fb_writel(0, VOUTC);

        return cable_type;
}

#ifdef CONFIG_PVR2_DMA
static ssize_t pvr2fb_write(struct fb_info *info, const char *buf,
                            size_t count, loff_t *ppos)
{
        unsigned long dst, start, end, len;
        unsigned int nr_pages;
        struct page **pages;
        int ret, i;

        nr_pages = (count + PAGE_SIZE - 1) >> PAGE_SHIFT;

        pages = kmalloc(nr_pages * sizeof(struct page *), GFP_KERNEL);
        if (!pages)
                return -ENOMEM;

        down_read(&current->mm->mmap_sem);
        ret = get_user_pages(current, current->mm, (unsigned long)buf,
                             nr_pages, WRITE, 0, pages, NULL);
        up_read(&current->mm->mmap_sem);

        if (ret < nr_pages) {
                nr_pages = ret;
                ret = -EINVAL;
                goto out_unmap;
        }

        dma_configure_channel(shdma, 0x12c1);

        dst   = (unsigned long)fb_info->screen_base + *ppos;
        start = (unsigned long)page_address(pages[0]);
        end   = (unsigned long)page_address(pages[nr_pages]);
        len   = nr_pages << PAGE_SHIFT;

        /* Half-assed contig check */
        if (start + len == end) {
                /* As we do this in one shot, it's either all or nothing.. */
                if ((*ppos + len) > fb_info->fix.smem_len) {
                        ret = -ENOSPC;
                        goto out_unmap;
                }

                dma_write(shdma, start, 0, len);
                dma_write(pvr2dma, 0, dst, len);
                dma_wait_for_completion(pvr2dma);

                goto out;
        }

        /* Not contiguous, writeout per-page instead.. */
        for (i = 0; i < nr_pages; i++, dst += PAGE_SIZE) {
                if ((*ppos + (i << PAGE_SHIFT)) > fb_info->fix.smem_len) {
                        ret = -ENOSPC;
                        goto out_unmap;
                }

                dma_write_page(shdma, (unsigned long)page_address(pages[i]), 0);
                dma_write_page(pvr2dma, 0, dst);
                dma_wait_for_completion(pvr2dma);
        }

out:
        *ppos += count;
        ret = count;

out_unmap:
        for (i = 0; i < nr_pages; i++)
                page_cache_release(pages[i]);

        kfree(pages);

        return ret;
}
#endif /* CONFIG_PVR2_DMA */

/**
 * pvr2fb_common_init
 *
 * Common init code for the PVR2 chips.
 *
 * This mostly takes care of the common aspects of the fb setup and
 * registration. It's expected that the board-specific init code has
 * already setup pvr2_fix with something meaningful at this point.
 *
 * Device info reporting is also done here, as well as picking a sane
 * default from the modedb. For board-specific modelines, simply define
 * a per-board modedb.
 *
 * Also worth noting is that the cable and video output types are likely
 * always going to be VGA for the PCI-based PVR2 boards, but we leave this
 * in for flexibility anyways. Who knows, maybe someone has tv-out on a
 * PCI-based version of these things ;-)
 */
static int pvr2fb_common_init(void)
{
        struct pvr2fb_par *par = currentpar;
        unsigned long modememused, rev;

        fb_info->screen_base = ioremap_nocache(pvr2_fix.smem_start,
                                               pvr2_fix.smem_len);

        if (!fb_info->screen_base) {
                printk(KERN_ERR "pvr2fb: Failed to remap smem space\n");
                goto out_err;
        }

        par->mmio_base = (unsigned long)ioremap_nocache(pvr2_fix.mmio_start,
                                                        pvr2_fix.mmio_len);
        if (!par->mmio_base) {
                printk(KERN_ERR "pvr2fb: Failed to remap mmio space\n");
                goto out_err;
        }

        fb_memset(fb_info->screen_base, 0, pvr2_fix.smem_len);

        pvr2_fix.ypanstep       = nopan  ? 0 : 1;
        pvr2_fix.ywrapstep      = nowrap ? 0 : 1;

        fb_info->fbops          = &pvr2fb_ops;
        fb_info->fix            = pvr2_fix;
        fb_info->par            = currentpar;
        fb_info->pseudo_palette = currentpar->palette;
        fb_info->flags          = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;

        if (video_output == VO_VGA)
                defmode = DEFMODE_VGA;

        if (!mode_option)
                mode_option = "640x480@60";

        if (!fb_find_mode(&fb_info->var, fb_info, mode_option, pvr2_modedb,
                          NUM_TOTAL_MODES, &pvr2_modedb[defmode], 16))
                fb_info->var = pvr2_var;

        fb_alloc_cmap(&fb_info->cmap, 256, 0);

        if (register_framebuffer(fb_info) < 0)
                goto out_err;
        /*Must write PIXDEPTH to register before anything is displayed - so force init */
        pvr2_init_display(fb_info);

        modememused = get_line_length(fb_info->var.xres_virtual,
                                      fb_info->var.bits_per_pixel);
        modememused *= fb_info->var.yres_virtual;

        rev = fb_readl(par->mmio_base + 0x04);

        printk("fb%d: %s (rev %ld.%ld) frame buffer device, using %ldk/%ldk of video memory\n",
               fb_info->node, fb_info->fix.id, (rev >> 4) & 0x0f, rev & 0x0f,
               modememused >> 10, (unsigned long)(fb_info->fix.smem_len >> 10));
        printk("fb%d: Mode %dx%d-%d pitch = %ld cable: %s video output: %s\n",
               fb_info->node, fb_info->var.xres, fb_info->var.yres,
               fb_info->var.bits_per_pixel,
               get_line_length(fb_info->var.xres, fb_info->var.bits_per_pixel),
               (char *)pvr2_get_param(cables, NULL, cable_type, 3),
               (char *)pvr2_get_param(outputs, NULL, video_output, 3));

#ifdef CONFIG_SH_STORE_QUEUES
        printk(KERN_NOTICE "fb%d: registering with SQ API\n", fb_info->node);

        pvr2fb_map = sq_remap(fb_info->fix.smem_start, fb_info->fix.smem_len,
                              fb_info->fix.id, PAGE_SHARED);

        printk(KERN_NOTICE "fb%d: Mapped video memory to SQ addr 0x%lx\n",
               fb_info->node, pvr2fb_map);
#endif

        return 0;

out_err:
        if (fb_info->screen_base)
                iounmap(fb_info->screen_base);
        if (par->mmio_base)
                iounmap((void *)par->mmio_base);

        return -ENXIO;
}

#ifdef CONFIG_SH_DREAMCAST
static int __init pvr2fb_dc_init(void)
{
        if (!mach_is_dreamcast())
                return -ENXIO;

        /* Make a guess at the monitor based on the attached cable */
        if (pvr2_init_cable() == CT_VGA) {
                fb_info->monspecs.hfmin = 30000;
                fb_info->monspecs.hfmax = 70000;
                fb_info->monspecs.vfmin = 60;
                fb_info->monspecs.vfmax = 60;
        } else {
                /* Not VGA, using a TV (taken from acornfb) */
                fb_info->monspecs.hfmin = 15469;
                fb_info->monspecs.hfmax = 15781;
                fb_info->monspecs.vfmin = 49;
                fb_info->monspecs.vfmax = 51;
        }

        /*
         * XXX: This needs to pull default video output via BIOS or other means
         */
        if (video_output < 0) {
                if (cable_type == CT_VGA) {
                        video_output = VO_VGA;
                } else {
                        video_output = VO_NTSC;
                }
        }

        /*
         * Nothing exciting about the DC PVR2 .. only a measly 8MiB.
         */
        pvr2_fix.smem_start     = 0xa5000000;   /* RAM starts here */
        pvr2_fix.smem_len       = 8 << 20;

        pvr2_fix.mmio_start     = 0xa05f8000;   /* registers start here */
        pvr2_fix.mmio_len       = 0x2000;

        if (request_irq(HW_EVENT_VSYNC, pvr2fb_interrupt, IRQF_SHARED,
                        "pvr2 VBL handler", fb_info)) {
                return -EBUSY;
        }

#ifdef CONFIG_PVR2_DMA
        if (request_dma(pvr2dma, "pvr2") != 0) {
                free_irq(HW_EVENT_VSYNC, fb_info);
                return -EBUSY;
        }
#endif

        return pvr2fb_common_init();
}

static void __exit pvr2fb_dc_exit(void)
{
        if (fb_info->screen_base) {
                iounmap(fb_info->screen_base);
                fb_info->screen_base = NULL;
        }
        if (currentpar->mmio_base) {
                iounmap((void *)currentpar->mmio_base);
                currentpar->mmio_base = 0;
        }

        free_irq(HW_EVENT_VSYNC, fb_info);
#ifdef CONFIG_PVR2_DMA
        free_dma(pvr2dma);
#endif
}
#endif /* CONFIG_SH_DREAMCAST */

#ifdef CONFIG_PCI
static int pvr2fb_pci_probe(struct pci_dev *pdev,
                            const struct pci_device_id *ent)
{
        int ret;

        ret = pci_enable_device(pdev);
        if (ret) {
                printk(KERN_ERR "pvr2fb: PCI enable failed\n");
                return ret;
        }

        ret = pci_request_regions(pdev, "pvr2fb");
        if (ret) {
                printk(KERN_ERR "pvr2fb: PCI request regions failed\n");
                return ret;
        }

        /*
         * Slightly more exciting than the DC PVR2 .. 16MiB!
         */
        pvr2_fix.smem_start     = pci_resource_start(pdev, 0);
        pvr2_fix.smem_len       = pci_resource_len(pdev, 0);

        pvr2_fix.mmio_start     = pci_resource_start(pdev, 1);
        pvr2_fix.mmio_len       = pci_resource_len(pdev, 1);

        fb_info->device         = &pdev->dev;

        return pvr2fb_common_init();
}

static void pvr2fb_pci_remove(struct pci_dev *pdev)
{
        if (fb_info->screen_base) {
                iounmap(fb_info->screen_base);
                fb_info->screen_base = NULL;
        }
        if (currentpar->mmio_base) {
                iounmap((void *)currentpar->mmio_base);
                currentpar->mmio_base = 0;
        }

        pci_release_regions(pdev);
}

static struct pci_device_id pvr2fb_pci_tbl[] = {
        { PCI_VENDOR_ID_NEC, PCI_DEVICE_ID_NEC_NEON250,
          PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
        { 0, },
};

MODULE_DEVICE_TABLE(pci, pvr2fb_pci_tbl);

static struct pci_driver pvr2fb_pci_driver = {
        .name           = "pvr2fb",
        .id_table       = pvr2fb_pci_tbl,
        .probe          = pvr2fb_pci_probe,
        .remove         = pvr2fb_pci_remove,
};

static int __init pvr2fb_pci_init(void)
{
        return pci_register_driver(&pvr2fb_pci_driver);
}

static void __exit pvr2fb_pci_exit(void)
{
        pci_unregister_driver(&pvr2fb_pci_driver);
}
#endif /* CONFIG_PCI */

static int pvr2_get_param(const struct pvr2_params *p, const char *s, int val,
                          int size)
{
        int i;

        for (i = 0 ; i < size ; i++ ) {
                if (s != NULL) {
                        if (!strnicmp(p[i].name, s, strlen(s)))
                                return p[i].val;
                } else {
                        if (p[i].val == val)
                                return (int)p[i].name;
                }
        }
        return -1;
}

/*
 * Parse command arguments.  Supported arguments are:
 *    inverse                             Use inverse color maps
 *    cable:composite|rgb|vga             Override the video cable type
 *    output:NTSC|PAL|VGA                 Override the video output format
 *
 *    <xres>x<yres>[-<bpp>][@<refresh>]   or,
 *    <name>[-<bpp>][@<refresh>]          Startup using this video mode
 */

#ifndef MODULE
static int __init pvr2fb_setup(char *options)
{
        char *this_opt;
        char cable_arg[80];
        char output_arg[80];

        if (!options || !*options)
                return 0;

        while ((this_opt = strsep(&options, ","))) {
                if (!*this_opt)
                        continue;
                if (!strcmp(this_opt, "inverse")) {
                        fb_invert_cmaps();
                } else if (!strncmp(this_opt, "cable:", 6)) {
                        strcpy(cable_arg, this_opt + 6);
                } else if (!strncmp(this_opt, "output:", 7)) {
                        strcpy(output_arg, this_opt + 7);
                } else if (!strncmp(this_opt, "nopan", 5)) {
                        nopan = 1;
                } else if (!strncmp(this_opt, "nowrap", 6)) {
                        nowrap = 1;
                } else {
                        mode_option = this_opt;
                }
        }

        if (*cable_arg)
                cable_type = pvr2_get_param(cables, cable_arg, 0, 3);
        if (*output_arg)
                video_output = pvr2_get_param(outputs, output_arg, 0, 3);

        return 0;
}
#endif

static struct pvr2_board {
        int (*init)(void);
        void (*exit)(void);
        char name[16];
} board_driver[] __refdata = {
#ifdef CONFIG_SH_DREAMCAST
        { pvr2fb_dc_init, pvr2fb_dc_exit, "Sega DC PVR2" },
#endif
#ifdef CONFIG_PCI
        { pvr2fb_pci_init, pvr2fb_pci_exit, "PCI PVR2" },
#endif
        { 0, },
};

static int __init pvr2fb_init(void)
{
        int i, ret = -ENODEV;
        int size;

#ifndef MODULE
        char *option = NULL;

        if (fb_get_options("pvr2fb", &option))
                return -ENODEV;
        pvr2fb_setup(option);
#endif
        size = sizeof(struct fb_info) + sizeof(struct pvr2fb_par) + 16 * sizeof(u32);

        fb_info = framebuffer_alloc(sizeof(struct pvr2fb_par), NULL);

        if (!fb_info) {
                printk(KERN_ERR "Failed to allocate memory for fb_info\n");
                return -ENOMEM;
        }


        currentpar = fb_info->par;

        for (i = 0; i < ARRAY_SIZE(board_driver); i++) {
                struct pvr2_board *pvr_board = board_driver + i;

                if (!pvr_board->init)
                        continue;

                ret = pvr_board->init();

                if (ret != 0) {
                        printk(KERN_ERR "pvr2fb: Failed init of %s device\n",
                                pvr_board->name);
                        framebuffer_release(fb_info);
                        break;
                }
        }

        return ret;
}

static void __exit pvr2fb_exit(void)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(board_driver); i++) {
                struct pvr2_board *pvr_board = board_driver + i;

                if (pvr_board->exit)
                        pvr_board->exit();
        }

#ifdef CONFIG_SH_STORE_QUEUES
        sq_unmap(pvr2fb_map);
#endif

        unregister_framebuffer(fb_info);
        framebuffer_release(fb_info);
}

module_init(pvr2fb_init);
module_exit(pvr2fb_exit);

MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, M. R. Brown <mrbrown@0xd6.org>");
MODULE_DESCRIPTION("Framebuffer driver for NEC PowerVR 2 based graphics boards");
MODULE_LICENSE("GPL");