atafb.c

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/*
 * linux/drivers/video/atafb.c -- Atari builtin chipset frame buffer device
 *
 *  Copyright (C) 1994 Martin Schaller & Roman Hodek
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 *
 * History:
 *   - 03 Jan 95: Original version by Martin Schaller: The TT driver and
 *                all the device independent stuff
 *   - 09 Jan 95: Roman: I've added the hardware abstraction (hw_switch)
 *                and wrote the Falcon, ST(E), and External drivers
 *                based on the original TT driver.
 *   - 07 May 95: Martin: Added colormap operations for the external driver
 *   - 21 May 95: Martin: Added support for overscan
 *        Andreas: some bug fixes for this
 *   -    Jul 95: Guenther Kelleter <[email protected]>:
 *                Programmable Falcon video modes
 *                (thanks to Christian Cartus for documentation
 *                of VIDEL registers).
 *   - 27 Dec 95: Guenther: Implemented user definable video modes "user[0-7]"
 *                on minor 24...31. "user0" may be set on commandline by
 *                "R<x>;<y>;<depth>". (Makes sense only on Falcon)
 *                Video mode switch on Falcon now done at next VBL interrupt
 *                to avoid the annoying right shift of the screen.
 *   - 23 Sep 97: Juergen: added xres_virtual for cards like ProMST
 *                The external-part is legacy, therefore hardware-specific
 *                functions like panning/hardwarescrolling/blanking isn't
 *                supported.
 *   - 29 Sep 97: Juergen: added Romans suggestion for pan_display
 *                (var->xoffset was changed even if no set_screen_base avail.)
 *   - 05 Oct 97: Juergen: extfb (PACKED_PIXEL) is FB_PSEUDOCOLOR 'cause
 *                we know how to set the colors
 *                ext_*palette: read from ext_colors (former MV300_colors)
 *                              write to ext_colors and RAMDAC
 *
 * To do:
 *   - For the Falcon it is not possible to set random video modes on
 *     SM124 and SC/TV, only the bootup resolution is supported.
 *
 */

#define ATAFB_TT
#define ATAFB_STE
#define ATAFB_EXT
#define ATAFB_FALCON

#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/init.h>
#include <linux/interrupt.h>

#include <asm/setup.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/irq.h>
#include <asm/io.h>

#include <asm/atarihw.h>
#include <asm/atariints.h>
#include <asm/atari_stram.h>

#include <linux/fb.h>
#include <asm/atarikb.h>

#include "c2p.h"
#include "atafb.h"

#define SWITCH_ACIA 0x01        /* modes for switch on OverScan */
#define SWITCH_SND6 0x40
#define SWITCH_SND7 0x80
#define SWITCH_NONE 0x00


#define up(x, r) (((x) + (r) - 1) & ~((r)-1))

    /*
     * Interface to the world
     */

static int atafb_check_var(struct fb_var_screeninfo *var, struct fb_info *info);
static int atafb_set_par(struct fb_info *info);
static int atafb_setcolreg(unsigned int regno, unsigned int red, unsigned int green,
               unsigned int blue, unsigned int transp,
               struct fb_info *info);
static int atafb_blank(int blank, struct fb_info *info);
static int atafb_pan_display(struct fb_var_screeninfo *var,
                 struct fb_info *info);
static void atafb_fillrect(struct fb_info *info,
               const struct fb_fillrect *rect);
static void atafb_copyarea(struct fb_info *info,
               const struct fb_copyarea *region);
static void atafb_imageblit(struct fb_info *info, const struct fb_image *image);
static int atafb_ioctl(struct fb_info *info, unsigned int cmd,
               unsigned long arg);


static int default_par;     /* default resolution (0=none) */

static unsigned long default_mem_req;

static int hwscroll = -1;

static int use_hwscroll = 1;

static int sttt_xres = 640, st_yres = 400, tt_yres = 480;
static int sttt_xres_virtual = 640, sttt_yres_virtual = 400;
static int ovsc_offset, ovsc_addlen;

    /*
     * Hardware parameters for current mode
     */

static struct atafb_par {
    void *screen_base;
    int yres_virtual;
    u_long next_line;
#if defined ATAFB_TT || defined ATAFB_STE
    union {
        struct {
            int mode;
            int sync;
        } tt, st;
#endif
#ifdef ATAFB_FALCON
        struct falcon_hw {
            /* Here are fields for storing a video mode, as direct
             * parameters for the hardware.
             */
            short sync;
            short line_width;
            short line_offset;
            short st_shift;
            short f_shift;
            short vid_control;
            short vid_mode;
            short xoffset;
            short hht, hbb, hbe, hdb, hde, hss;
            short vft, vbb, vbe, vdb, vde, vss;
            /* auxiliary information */
            short mono;
            short ste_mode;
            short bpp;
            u32 pseudo_palette[16];
        } falcon;
#endif
        /* Nothing needed for external mode */
    } hw;
} current_par;

/* Don't calculate an own resolution, and thus don't change the one found when
 * booting (currently used for the Falcon to keep settings for internal video
 * hardware extensions (e.g. ScreenBlaster)  */
static int DontCalcRes = 0;

#ifdef ATAFB_FALCON
#define HHT hw.falcon.hht
#define HBB hw.falcon.hbb
#define HBE hw.falcon.hbe
#define HDB hw.falcon.hdb
#define HDE hw.falcon.hde
#define HSS hw.falcon.hss
#define VFT hw.falcon.vft
#define VBB hw.falcon.vbb
#define VBE hw.falcon.vbe
#define VDB hw.falcon.vdb
#define VDE hw.falcon.vde
#define VSS hw.falcon.vss
#define VCO_CLOCK25     0x04
#define VCO_CSYPOS      0x10
#define VCO_VSYPOS      0x20
#define VCO_HSYPOS      0x40
#define VCO_SHORTOFFS   0x100
#define VMO_DOUBLE      0x01
#define VMO_INTER       0x02
#define VMO_PREMASK     0x0c
#endif

static struct fb_info fb_info = {
    .fix = {
        .id = "Atari ",
        .visual = FB_VISUAL_PSEUDOCOLOR,
        .accel  = FB_ACCEL_NONE,
    }
};

static void *screen_base;   /* base address of screen */
static void *real_screen_base;  /* (only for Overscan) */

static int screen_len;

static int current_par_valid;

static int mono_moni;


#ifdef ATAFB_EXT

/* external video handling */
static unsigned int external_xres;
static unsigned int external_xres_virtual;
static unsigned int external_yres;

/*
 * not needed - atafb will never support panning/hardwarescroll with external
 * static unsigned int external_yres_virtual;
 */
static unsigned int external_depth;
static int external_pmode;
static void *external_addr;
static unsigned long external_len;
static unsigned long external_vgaiobase;
static unsigned int external_bitspercol = 6;

/*
 * JOE <[email protected]>:
 * added card type for external driver, is only needed for
 * colormap handling.
 */
enum cardtype { IS_VGA, IS_MV300 };
static enum cardtype external_card_type = IS_VGA;

/*
 * The MV300 mixes the color registers. So we need an array of munged
 * indices in order to access the correct reg.
 */
static int MV300_reg_1bit[2] = {
    0, 1
};
static int MV300_reg_4bit[16] = {
    0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15
};
static int MV300_reg_8bit[256] = {
    0, 128, 64, 192, 32, 160, 96, 224, 16, 144, 80, 208, 48, 176, 112, 240,
    8, 136, 72, 200, 40, 168, 104, 232, 24, 152, 88, 216, 56, 184, 120, 248,
    4, 132, 68, 196, 36, 164, 100, 228, 20, 148, 84, 212, 52, 180, 116, 244,
    12, 140, 76, 204, 44, 172, 108, 236, 28, 156, 92, 220, 60, 188, 124, 252,
    2, 130, 66, 194, 34, 162, 98, 226, 18, 146, 82, 210, 50, 178, 114, 242,
    10, 138, 74, 202, 42, 170, 106, 234, 26, 154, 90, 218, 58, 186, 122, 250,
    6, 134, 70, 198, 38, 166, 102, 230, 22, 150, 86, 214, 54, 182, 118, 246,
    14, 142, 78, 206, 46, 174, 110, 238, 30, 158, 94, 222, 62, 190, 126, 254,
    1, 129, 65, 193, 33, 161, 97, 225, 17, 145, 81, 209, 49, 177, 113, 241,
    9, 137, 73, 201, 41, 169, 105, 233, 25, 153, 89, 217, 57, 185, 121, 249,
    5, 133, 69, 197, 37, 165, 101, 229, 21, 149, 85, 213, 53, 181, 117, 245,
    13, 141, 77, 205, 45, 173, 109, 237, 29, 157, 93, 221, 61, 189, 125, 253,
    3, 131, 67, 195, 35, 163, 99, 227, 19, 147, 83, 211, 51, 179, 115, 243,
    11, 139, 75, 203, 43, 171, 107, 235, 27, 155, 91, 219, 59, 187, 123, 251,
    7, 135, 71, 199, 39, 167, 103, 231, 23, 151, 87, 215, 55, 183, 119, 247,
    15, 143, 79, 207, 47, 175, 111, 239, 31, 159, 95, 223, 63, 191, 127, 255
};

static int *MV300_reg = MV300_reg_8bit;
#endif /* ATAFB_EXT */


static int inverse;

extern int fontheight_8x8;
extern int fontwidth_8x8;
extern unsigned char fontdata_8x8[];

extern int fontheight_8x16;
extern int fontwidth_8x16;
extern unsigned char fontdata_8x16[];

/*
 * struct fb_ops {
 *  * open/release and usage marking
 *  struct module *owner;
 *  int (*fb_open)(struct fb_info *info, int user);
 *  int (*fb_release)(struct fb_info *info, int user);
 *
 *  * For framebuffers with strange non linear layouts or that do not
 *  * work with normal memory mapped access
 *  ssize_t (*fb_read)(struct file *file, char __user *buf, size_t count, loff_t *ppos);
 *  ssize_t (*fb_write)(struct file *file, const char __user *buf, size_t count, loff_t *ppos);
 *
 *  * checks var and eventually tweaks it to something supported,
 *  * DOES NOT MODIFY PAR *
 *  int (*fb_check_var)(struct fb_var_screeninfo *var, struct fb_info *info);
 *
 *  * set the video mode according to info->var *
 *  int (*fb_set_par)(struct fb_info *info);
 *
 *  * set color register *
 *  int (*fb_setcolreg)(unsigned int regno, unsigned int red, unsigned int green,
 *              unsigned int blue, unsigned int transp, struct fb_info *info);
 *
 *  * set color registers in batch *
 *  int (*fb_setcmap)(struct fb_cmap *cmap, struct fb_info *info);
 *
 *  * blank display *
 *  int (*fb_blank)(int blank, struct fb_info *info);
 *
 *  * pan display *
 *  int (*fb_pan_display)(struct fb_var_screeninfo *var, struct fb_info *info);
 *
 *  *** The meat of the drawing engine ***
 *  * Draws a rectangle *
 *  void (*fb_fillrect) (struct fb_info *info, const struct fb_fillrect *rect);
 *  * Copy data from area to another *
 *  void (*fb_copyarea) (struct fb_info *info, const struct fb_copyarea *region);
 *  * Draws a image to the display *
 *  void (*fb_imageblit) (struct fb_info *info, const struct fb_image *image);
 *
 *  * Draws cursor *
 *  int (*fb_cursor) (struct fb_info *info, struct fb_cursor *cursor);
 *
 *  * Rotates the display *
 *  void (*fb_rotate)(struct fb_info *info, int angle);
 *
 *  * wait for blit idle, optional *
 *  int (*fb_sync)(struct fb_info *info);
 *
 *  * perform fb specific ioctl (optional) *
 *  int (*fb_ioctl)(struct fb_info *info, unsigned int cmd,
 *          unsigned long arg);
 *
 *  * Handle 32bit compat ioctl (optional) *
 *  int (*fb_compat_ioctl)(struct fb_info *info, unsigned int cmd,
 *          unsigned long arg);
 *
 *  * perform fb specific mmap *
 *  int (*fb_mmap)(struct fb_info *info, struct vm_area_struct *vma);
 * } ;
 */


/* ++roman: This structure abstracts from the underlying hardware (ST(e),
 * TT, or Falcon.
 *
 * int (*detect)(void)
 *   This function should detect the current video mode settings and
 *   store them in atafb_predefined[0] for later reference by the
 *   user. Return the index+1 of an equivalent predefined mode or 0
 *   if there is no such.
 *
 * int (*encode_fix)(struct fb_fix_screeninfo *fix,
 *                   struct atafb_par *par)
 *   This function should fill in the 'fix' structure based on the
 *   values in the 'par' structure.
 * !!! Obsolete, perhaps !!!
 *
 * int (*decode_var)(struct fb_var_screeninfo *var,
 *                   struct atafb_par *par)
 *   Get the video params out of 'var'. If a value doesn't fit, round
 *   it up, if it's too big, return EINVAL.
 *   Round up in the following order: bits_per_pixel, xres, yres,
 *   xres_virtual, yres_virtual, xoffset, yoffset, grayscale, bitfields,
 *   horizontal timing, vertical timing.
 *
 * int (*encode_var)(struct fb_var_screeninfo *var,
 *                   struct atafb_par *par);
 *   Fill the 'var' structure based on the values in 'par' and maybe
 *   other values read out of the hardware.
 *
 * void (*get_par)(struct atafb_par *par)
 *   Fill the hardware's 'par' structure.
 *   !!! Used only by detect() !!!
 *
 * void (*set_par)(struct atafb_par *par)
 *   Set the hardware according to 'par'.
 *
 * void (*set_screen_base)(void *s_base)
 *   Set the base address of the displayed frame buffer. Only called
 *   if yres_virtual > yres or xres_virtual > xres.
 *
 * int (*blank)(int blank_mode)
 *   Blank the screen if blank_mode != 0, else unblank. If blank == NULL then
 *   the caller blanks by setting the CLUT to all black. Return 0 if blanking
 *   succeeded, !=0 if un-/blanking failed due to e.g. a video mode which
 *   doesn't support it. Implements VESA suspend and powerdown modes on
 *   hardware that supports disabling hsync/vsync:
 *       blank_mode == 2: suspend vsync, 3:suspend hsync, 4: powerdown.
 */

static struct fb_hwswitch {
    int (*detect)(void);
    int (*encode_fix)(struct fb_fix_screeninfo *fix,
              struct atafb_par *par);
    int (*decode_var)(struct fb_var_screeninfo *var,
              struct atafb_par *par);
    int (*encode_var)(struct fb_var_screeninfo *var,
              struct atafb_par *par);
    void (*get_par)(struct atafb_par *par);
    void (*set_par)(struct atafb_par *par);
    void (*set_screen_base)(void *s_base);
    int (*blank)(int blank_mode);
    int (*pan_display)(struct fb_var_screeninfo *var,
               struct fb_info *info);
} *fbhw;

static char *autodetect_names[] = { "autodetect", NULL };
static char *stlow_names[] = { "stlow", NULL };
static char *stmid_names[] = { "stmid", "default5", NULL };
static char *sthigh_names[] = { "sthigh", "default4", NULL };
static char *ttlow_names[] = { "ttlow", NULL };
static char *ttmid_names[] = { "ttmid", "default1", NULL };
static char *tthigh_names[] = { "tthigh", "default2", NULL };
static char *vga2_names[] = { "vga2", NULL };
static char *vga4_names[] = { "vga4", NULL };
static char *vga16_names[] = { "vga16", "default3", NULL };
static char *vga256_names[] = { "vga256", NULL };
static char *falh2_names[] = { "falh2", NULL };
static char *falh16_names[] = { "falh16", NULL };

static char **fb_var_names[] = {
    autodetect_names,
    stlow_names,
    stmid_names,
    sthigh_names,
    ttlow_names,
    ttmid_names,
    tthigh_names,
    vga2_names,
    vga4_names,
    vga16_names,
    vga256_names,
    falh2_names,
    falh16_names,
    NULL
};

static struct fb_var_screeninfo atafb_predefined[] = {
    /*
     * yres_virtual == 0 means use hw-scrolling if possible, else yres
     */
    { /* autodetect */
      0, 0, 0, 0, 0, 0, 0, 0,       /* xres-grayscale */
      {0, 0, 0}, {0, 0, 0}, {0, 0, 0}, {0, 0, 0},   /* red green blue tran*/
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* st low */
      320, 200, 320, 0, 0, 0, 4, 0,
      {0, 4, 0}, {0, 4, 0}, {0, 4, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* st mid */
      640, 200, 640, 0, 0, 0, 2, 0,
      {0, 4, 0}, {0, 4, 0}, {0, 4, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* st high */
      640, 400, 640, 0, 0, 0, 1, 0,
      {0, 4, 0}, {0, 4, 0}, {0, 4, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* tt low */
      320, 480, 320, 0, 0, 0, 8, 0,
      {0, 4, 0}, {0, 4, 0}, {0, 4, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* tt mid */
      640, 480, 640, 0, 0, 0, 4, 0,
      {0, 4, 0}, {0, 4, 0}, {0, 4, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* tt high */
      1280, 960, 1280, 0, 0, 0, 1, 0,
      {0, 4, 0}, {0, 4, 0}, {0, 4, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* vga2 */
      640, 480, 640, 0, 0, 0, 1, 0,
      {0, 6, 0}, {0, 6, 0}, {0, 6, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* vga4 */
      640, 480, 640, 0, 0, 0, 2, 0,
      {0, 4, 0}, {0, 4, 0}, {0, 4, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* vga16 */
      640, 480, 640, 0, 0, 0, 4, 0,
      {0, 6, 0}, {0, 6, 0}, {0, 6, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* vga256 */
      640, 480, 640, 0, 0, 0, 8, 0,
      {0, 6, 0}, {0, 6, 0}, {0, 6, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* falh2 */
      896, 608, 896, 0, 0, 0, 1, 0,
      {0, 6, 0}, {0, 6, 0}, {0, 6, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
    { /* falh16 */
      896, 608, 896, 0, 0, 0, 4, 0,
      {0, 6, 0}, {0, 6, 0}, {0, 6, 0}, {0, 0, 0},
      0, 0, -1, -1, 0, 0, 0, 0, 0, 0, 0, 0 },
};

static int num_atafb_predefined = ARRAY_SIZE(atafb_predefined);

static struct fb_videomode atafb_modedb[] __initdata = {
    /*
     *  Atari Video Modes
     *
     *  If you change these, make sure to update DEFMODE_* as well!
     */

    /*
     *  ST/TT Video Modes
     */

    {
        /* 320x200, 15 kHz, 60 Hz (ST low) */
        "st-low", 60, 320, 200, 32000, 32, 16, 31, 14, 96, 4,
        0, FB_VMODE_NONINTERLACED | FB_VMODE_YWRAP
    }, {
        /* 640x200, 15 kHz, 60 Hz (ST medium) */
        "st-mid", 60, 640, 200, 32000, 32, 16, 31, 14, 96, 4,
        0, FB_VMODE_NONINTERLACED | FB_VMODE_YWRAP
    }, {
        /* 640x400, 30.25 kHz, 63.5 Hz (ST high) */
        "st-high", 63, 640, 400, 32000, 128, 0, 40, 14, 128, 4,
        0, FB_VMODE_NONINTERLACED | FB_VMODE_YWRAP
    }, {
        /* 320x480, 15 kHz, 60 Hz (TT low) */
        "tt-low", 60, 320, 480, 31041, 120, 100, 8, 16, 140, 30,
        0, FB_VMODE_NONINTERLACED | FB_VMODE_YWRAP
    }, {
        /* 640x480, 29 kHz, 57 Hz (TT medium) */
        "tt-mid", 60, 640, 480, 31041, 120, 100, 8, 16, 140, 30,
        0, FB_VMODE_NONINTERLACED | FB_VMODE_YWRAP
    }, {
        /* 1280x960, 29 kHz, 60 Hz (TT high) */
        "tt-high", 57, 640, 960, 31041, 120, 100, 8, 16, 140, 30,
        0, FB_VMODE_NONINTERLACED | FB_VMODE_YWRAP
    },

    /*
     *  VGA Video Modes
     */

    {
        /* 640x480, 31 kHz, 60 Hz (VGA) */
        "vga", 63.5, 640, 480, 32000, 18, 42, 31, 11, 96, 3,
        0, FB_VMODE_NONINTERLACED | FB_VMODE_YWRAP
    }, {
        /* 640x400, 31 kHz, 70 Hz (VGA) */
        "vga70", 70, 640, 400, 32000, 18, 42, 31, 11, 96, 3,
        FB_SYNC_VERT_HIGH_ACT | FB_SYNC_COMP_HIGH_ACT, FB_VMODE_NONINTERLACED | FB_VMODE_YWRAP
    },

    /*
     *  Falcon HiRes Video Modes
     */

    {
        /* 896x608, 31 kHz, 60 Hz (Falcon High) */
        "falh", 60, 896, 608, 32000, 18, 42, 31, 1, 96,3,
        0, FB_VMODE_NONINTERLACED | FB_VMODE_YWRAP
    },
};

#define NUM_TOTAL_MODES  ARRAY_SIZE(atafb_modedb)

static char *mode_option __initdata = NULL;

 /* default modes */

#define DEFMODE_TT  5       /* "tt-high" for TT */
#define DEFMODE_F30 7       /* "vga70" for Falcon */
#define DEFMODE_STE 2       /* "st-high" for ST/E */
#define DEFMODE_EXT 6       /* "vga" for external */


static int get_video_mode(char *vname)
{
    char ***name_list;
    char **name;
    int i;

    name_list = fb_var_names;
    for (i = 0; i < num_atafb_predefined; i++) {
        name = *name_list++;
        if (!name || !*name)
            break;
        while (*name) {
            if (!strcmp(vname, *name))
                return i + 1;
            name++;
        }
    }
    return 0;
}



/* ------------------- TT specific functions ---------------------- */

#ifdef ATAFB_TT

static int tt_encode_fix(struct fb_fix_screeninfo *fix, struct atafb_par *par)
{
    int mode;

    strcpy(fix->id, "Atari Builtin");
    fix->smem_start = (unsigned long)real_screen_base;
    fix->smem_len = screen_len;
    fix->type = FB_TYPE_INTERLEAVED_PLANES;
    fix->type_aux = 2;
    fix->visual = FB_VISUAL_PSEUDOCOLOR;
    mode = par->hw.tt.mode & TT_SHIFTER_MODEMASK;
    if (mode == TT_SHIFTER_TTHIGH || mode == TT_SHIFTER_STHIGH) {
        fix->type = FB_TYPE_PACKED_PIXELS;
        fix->type_aux = 0;
        if (mode == TT_SHIFTER_TTHIGH)
            fix->visual = FB_VISUAL_MONO01;
    }
    fix->xpanstep = 0;
    fix->ypanstep = 1;
    fix->ywrapstep = 0;
    fix->line_length = par->next_line;
    fix->accel = FB_ACCEL_ATARIBLITT;
    return 0;
}

static int tt_decode_var(struct fb_var_screeninfo *var, struct atafb_par *par)
{
    int xres = var->xres;
    int yres = var->yres;
    int bpp = var->bits_per_pixel;
    int linelen;
    int yres_virtual = var->yres_virtual;

    if (mono_moni) {
        if (bpp > 1 || xres > sttt_xres * 2 || yres > tt_yres * 2)
            return -EINVAL;
        par->hw.tt.mode = TT_SHIFTER_TTHIGH;
        xres = sttt_xres * 2;
        yres = tt_yres * 2;
        bpp = 1;
    } else {
        if (bpp > 8 || xres > sttt_xres || yres > tt_yres)
            return -EINVAL;
        if (bpp > 4) {
            if (xres > sttt_xres / 2 || yres > tt_yres)
                return -EINVAL;
            par->hw.tt.mode = TT_SHIFTER_TTLOW;
            xres = sttt_xres / 2;
            yres = tt_yres;
            bpp = 8;
        } else if (bpp > 2) {
            if (xres > sttt_xres || yres > tt_yres)
                return -EINVAL;
            if (xres > sttt_xres / 2 || yres > st_yres / 2) {
                par->hw.tt.mode = TT_SHIFTER_TTMID;
                xres = sttt_xres;
                yres = tt_yres;
                bpp = 4;
            } else {
                par->hw.tt.mode = TT_SHIFTER_STLOW;
                xres = sttt_xres / 2;
                yres = st_yres / 2;
                bpp = 4;
            }
        } else if (bpp > 1) {
            if (xres > sttt_xres || yres > st_yres / 2)
                return -EINVAL;
            par->hw.tt.mode = TT_SHIFTER_STMID;
            xres = sttt_xres;
            yres = st_yres / 2;
            bpp = 2;
        } else if (var->xres > sttt_xres || var->yres > st_yres) {
            return -EINVAL;
        } else {
            par->hw.tt.mode = TT_SHIFTER_STHIGH;
            xres = sttt_xres;
            yres = st_yres;
            bpp = 1;
        }
    }
    if (yres_virtual <= 0)
        yres_virtual = 0;
    else if (yres_virtual < yres)
        yres_virtual = yres;
    if (var->sync & FB_SYNC_EXT)
        par->hw.tt.sync = 0;
    else
        par->hw.tt.sync = 1;
    linelen = xres * bpp / 8;
    if (yres_virtual * linelen > screen_len && screen_len)
        return -EINVAL;
    if (yres * linelen > screen_len && screen_len)
        return -EINVAL;
    if (var->yoffset + yres > yres_virtual && yres_virtual)
        return -EINVAL;
    par->yres_virtual = yres_virtual;
    par->screen_base = screen_base + var->yoffset * linelen;
    par->next_line = linelen;
    return 0;
}

static int tt_encode_var(struct fb_var_screeninfo *var, struct atafb_par *par)
{
    int linelen;
    memset(var, 0, sizeof(struct fb_var_screeninfo));
    var->red.offset = 0;
    var->red.length = 4;
    var->red.msb_right = 0;
    var->grayscale = 0;

    var->pixclock = 31041;
    var->left_margin = 120;     /* these may be incorrect */
    var->right_margin = 100;
    var->upper_margin = 8;
    var->lower_margin = 16;
    var->hsync_len = 140;
    var->vsync_len = 30;

    var->height = -1;
    var->width = -1;

    if (par->hw.tt.sync & 1)
        var->sync = 0;
    else
        var->sync = FB_SYNC_EXT;

    switch (par->hw.tt.mode & TT_SHIFTER_MODEMASK) {
    case TT_SHIFTER_STLOW:
        var->xres = sttt_xres / 2;
        var->xres_virtual = sttt_xres_virtual / 2;
        var->yres = st_yres / 2;
        var->bits_per_pixel = 4;
        break;
    case TT_SHIFTER_STMID:
        var->xres = sttt_xres;
        var->xres_virtual = sttt_xres_virtual;
        var->yres = st_yres / 2;
        var->bits_per_pixel = 2;
        break;
    case TT_SHIFTER_STHIGH:
        var->xres = sttt_xres;
        var->xres_virtual = sttt_xres_virtual;
        var->yres = st_yres;
        var->bits_per_pixel = 1;
        break;
    case TT_SHIFTER_TTLOW:
        var->xres = sttt_xres / 2;
        var->xres_virtual = sttt_xres_virtual / 2;
        var->yres = tt_yres;
        var->bits_per_pixel = 8;
        break;
    case TT_SHIFTER_TTMID:
        var->xres = sttt_xres;
        var->xres_virtual = sttt_xres_virtual;
        var->yres = tt_yres;
        var->bits_per_pixel = 4;
        break;
    case TT_SHIFTER_TTHIGH:
        var->red.length = 0;
        var->xres = sttt_xres * 2;
        var->xres_virtual = sttt_xres_virtual * 2;
        var->yres = tt_yres * 2;
        var->bits_per_pixel = 1;
        break;
    }
    var->blue = var->green = var->red;
    var->transp.offset = 0;
    var->transp.length = 0;
    var->transp.msb_right = 0;
    linelen = var->xres_virtual * var->bits_per_pixel / 8;
    if (!use_hwscroll)
        var->yres_virtual = var->yres;
    else if (screen_len) {
        if (par->yres_virtual)
            var->yres_virtual = par->yres_virtual;
        else
            /* yres_virtual == 0 means use maximum */
            var->yres_virtual = screen_len / linelen;
    } else {
        if (hwscroll < 0)
            var->yres_virtual = 2 * var->yres;
        else
            var->yres_virtual = var->yres + hwscroll * 16;
    }
    var->xoffset = 0;
    if (screen_base)
        var->yoffset = (par->screen_base - screen_base) / linelen;
    else
        var->yoffset = 0;
    var->nonstd = 0;
    var->activate = 0;
    var->vmode = FB_VMODE_NONINTERLACED;
    return 0;
}

static void tt_get_par(struct atafb_par *par)
{
    unsigned long addr;
    par->hw.tt.mode = shifter_tt.tt_shiftmode;
    par->hw.tt.sync = shifter.syncmode;
    addr = ((shifter.bas_hi & 0xff) << 16) |
           ((shifter.bas_md & 0xff) << 8)  |
           ((shifter.bas_lo & 0xff));
    par->screen_base = phys_to_virt(addr);
}

static void tt_set_par(struct atafb_par *par)
{
    shifter_tt.tt_shiftmode = par->hw.tt.mode;
    shifter.syncmode = par->hw.tt.sync;
    /* only set screen_base if really necessary */
    if (current_par.screen_base != par->screen_base)
        fbhw->set_screen_base(par->screen_base);
}

static int tt_setcolreg(unsigned int regno, unsigned int red,
            unsigned int green, unsigned int blue,
            unsigned int transp, struct fb_info *info)
{
    if ((shifter_tt.tt_shiftmode & TT_SHIFTER_MODEMASK) == TT_SHIFTER_STHIGH)
        regno += 254;
    if (regno > 255)
        return 1;
    tt_palette[regno] = (((red >> 12) << 8) | ((green >> 12) << 4) |
                 (blue >> 12));
    if ((shifter_tt.tt_shiftmode & TT_SHIFTER_MODEMASK) ==
        TT_SHIFTER_STHIGH && regno == 254)
        tt_palette[0] = 0;
    return 0;
}

static int tt_detect(void)
{
    struct atafb_par par;

    /* Determine the connected monitor: The DMA sound must be
     * disabled before reading the MFP GPIP, because the Sound
     * Done Signal and the Monochrome Detect are XORed together!
     *
     * Even on a TT, we should look if there is a DMA sound. It was
     * announced that the Eagle is TT compatible, but only the PCM is
     * missing...
     */
    if (ATARIHW_PRESENT(PCM_8BIT)) {
        tt_dmasnd.ctrl = DMASND_CTRL_OFF;
        udelay(20);     /* wait a while for things to settle down */
    }
    mono_moni = (st_mfp.par_dt_reg & 0x80) == 0;

    tt_get_par(&par);
    tt_encode_var(&atafb_predefined[0], &par);

    return 1;
}

#endif /* ATAFB_TT */

/* ------------------- Falcon specific functions ---------------------- */

#ifdef ATAFB_FALCON

static int mon_type;        /* Falcon connected monitor */
static int f030_bus_width;  /* Falcon ram bus width (for vid_control) */
#define F_MON_SM    0
#define F_MON_SC    1
#define F_MON_VGA   2
#define F_MON_TV    3

static struct pixel_clock {
    unsigned long f;    /* f/[Hz] */
    unsigned long t;    /* t/[ps] (=1/f) */
    int right, hsync, left; /* standard timing in clock cycles, not pixel */
    /* hsync initialized in falcon_detect() */
    int sync_mask;      /* or-mask for hw.falcon.sync to set this clock */
    int control_mask;   /* ditto, for hw.falcon.vid_control */
} f25 = {
    25175000, 39721, 18, 0, 42, 0x0, VCO_CLOCK25
}, f32 = {
    32000000, 31250, 18, 0, 42, 0x0, 0
}, fext = {
    0, 0, 18, 0, 42, 0x1, 0
};

/* VIDEL-prescale values [mon_type][pixel_length from VCO] */
static int vdl_prescale[4][3] = {
    { 4,2,1 }, { 4,2,1 }, { 4,2,2 }, { 4,2,1 }
};

/* Default hsync timing [mon_type] in picoseconds */
static long h_syncs[4] = { 3000000, 4875000, 4000000, 4875000 };

static inline int hxx_prescale(struct falcon_hw *hw)
{
    return hw->ste_mode ? 16
                : vdl_prescale[mon_type][hw->vid_mode >> 2 & 0x3];
}

static int falcon_encode_fix(struct fb_fix_screeninfo *fix,
                 struct atafb_par *par)
{
    strcpy(fix->id, "Atari Builtin");
    fix->smem_start = (unsigned long)real_screen_base;
    fix->smem_len = screen_len;
    fix->type = FB_TYPE_INTERLEAVED_PLANES;
    fix->type_aux = 2;
    fix->visual = FB_VISUAL_PSEUDOCOLOR;
    fix->xpanstep = 1;
    fix->ypanstep = 1;
    fix->ywrapstep = 0;
    if (par->hw.falcon.mono) {
        fix->type = FB_TYPE_PACKED_PIXELS;
        fix->type_aux = 0;
        /* no smooth scrolling with longword aligned video mem */
        fix->xpanstep = 32;
    } else if (par->hw.falcon.f_shift & 0x100) {
        fix->type = FB_TYPE_PACKED_PIXELS;
        fix->type_aux = 0;
        /* Is this ok or should it be DIRECTCOLOR? */
        fix->visual = FB_VISUAL_TRUECOLOR;
        fix->xpanstep = 2;
    }
    fix->line_length = par->next_line;
    fix->accel = FB_ACCEL_ATARIBLITT;
    return 0;
}

static int falcon_decode_var(struct fb_var_screeninfo *var,
                 struct atafb_par *par)
{
    int bpp = var->bits_per_pixel;
    int xres = var->xres;
    int yres = var->yres;
    int xres_virtual = var->xres_virtual;
    int yres_virtual = var->yres_virtual;
    int left_margin, right_margin, hsync_len;
    int upper_margin, lower_margin, vsync_len;
    int linelen;
    int interlace = 0, doubleline = 0;
    struct pixel_clock *pclock;
    int plen;           /* width of pixel in clock cycles */
    int xstretch;
    int prescale;
    int longoffset = 0;
    int hfreq, vfreq;
    int hdb_off, hde_off, base_off;
    int gstart, gend1, gend2, align;

/*
    Get the video params out of 'var'. If a value doesn't fit, round
    it up, if it's too big, return EINVAL.
    Round up in the following order: bits_per_pixel, xres, yres,
    xres_virtual, yres_virtual, xoffset, yoffset, grayscale, bitfields,
    horizontal timing, vertical timing.

    There is a maximum of screen resolution determined by pixelclock
    and minimum frame rate -- (X+hmarg.)*(Y+vmarg.)*vfmin <= pixelclock.
    In interlace mode this is     "     *    "     *vfmin <= pixelclock.
    Additional constraints: hfreq.
    Frequency range for multisync monitors is given via command line.
    For TV and SM124 both frequencies are fixed.

    X % 16 == 0 to fit 8x?? font (except 1 bitplane modes must use X%32 == 0)
    Y % 16 == 0 to fit 8x16 font
    Y % 8 == 0 if Y<400

    Currently interlace and doubleline mode in var are ignored.
    On SM124 and TV only the standard resolutions can be used.
*/

    /* Reject uninitialized mode */
    if (!xres || !yres || !bpp)
        return -EINVAL;

    if (mon_type == F_MON_SM && bpp != 1)
        return -EINVAL;

    if (bpp <= 1) {
        bpp = 1;
        par->hw.falcon.f_shift = 0x400;
        par->hw.falcon.st_shift = 0x200;
    } else if (bpp <= 2) {
        bpp = 2;
        par->hw.falcon.f_shift = 0x000;
        par->hw.falcon.st_shift = 0x100;
    } else if (bpp <= 4) {
        bpp = 4;
        par->hw.falcon.f_shift = 0x000;
        par->hw.falcon.st_shift = 0x000;
    } else if (bpp <= 8) {
        bpp = 8;
        par->hw.falcon.f_shift = 0x010;
    } else if (bpp <= 16) {
        bpp = 16;       /* packed pixel mode */
        par->hw.falcon.f_shift = 0x100; /* hicolor, no overlay */
    } else
        return -EINVAL;
    par->hw.falcon.bpp = bpp;

    if (mon_type == F_MON_SM || DontCalcRes) {
        /* Skip all calculations. VGA/TV/SC1224 only supported. */
        struct fb_var_screeninfo *myvar = &atafb_predefined[0];

        if (bpp > myvar->bits_per_pixel ||
            var->xres > myvar->xres ||
            var->yres > myvar->yres)
            return -EINVAL;
        fbhw->get_par(par); /* Current par will be new par */
        goto set_screen_base;   /* Don't forget this */
    }

    /* Only some fixed resolutions < 640x400 */
    if (xres <= 320)
        xres = 320;
    else if (xres <= 640 && bpp != 16)
        xres = 640;
    if (yres <= 200)
        yres = 200;
    else if (yres <= 240)
        yres = 240;
    else if (yres <= 400)
        yres = 400;

    /* 2 planes must use STE compatibility mode */
    par->hw.falcon.ste_mode = bpp == 2;
    par->hw.falcon.mono = bpp == 1;

    /* Total and visible scanline length must be a multiple of one longword,
     * this and the console fontwidth yields the alignment for xres and
     * xres_virtual.
     * TODO: this way "odd" fontheights are not supported
     *
     * Special case in STE mode: blank and graphic positions don't align,
     * avoid trash at right margin
     */
    if (par->hw.falcon.ste_mode)
        xres = (xres + 63) & ~63;
    else if (bpp == 1)
        xres = (xres + 31) & ~31;
    else
        xres = (xres + 15) & ~15;
    if (yres >= 400)
        yres = (yres + 15) & ~15;
    else
        yres = (yres + 7) & ~7;

    if (xres_virtual < xres)
        xres_virtual = xres;
    else if (bpp == 1)
        xres_virtual = (xres_virtual + 31) & ~31;
    else
        xres_virtual = (xres_virtual + 15) & ~15;

    if (yres_virtual <= 0)
        yres_virtual = 0;
    else if (yres_virtual < yres)
        yres_virtual = yres;

    /* backward bug-compatibility */
    if (var->pixclock > 1)
        var->pixclock -= 1;

    par->hw.falcon.line_width = bpp * xres / 16;
    par->hw.falcon.line_offset = bpp * (xres_virtual - xres) / 16;

    /* single or double pixel width */
    xstretch = (xres < 640) ? 2 : 1;

#if 0 /* SM124 supports only 640x400, this is rejected above */
    if (mon_type == F_MON_SM) {
        if (xres != 640 && yres != 400)
            return -EINVAL;
        plen = 1;
        pclock = &f32;
        /* SM124-mode is special */
        par->hw.falcon.ste_mode = 1;
        par->hw.falcon.f_shift = 0x000;
        par->hw.falcon.st_shift = 0x200;
        left_margin = hsync_len = 128 / plen;
        right_margin = 0;
        /* TODO set all margins */
    } else
#endif
    if (mon_type == F_MON_SC || mon_type == F_MON_TV) {
        plen = 2 * xstretch;
        if (var->pixclock > f32.t * plen)
            return -EINVAL;
        pclock = &f32;
        if (yres > 240)
            interlace = 1;
        if (var->pixclock == 0) {
            /* set some minimal margins which center the screen */
            left_margin = 32;
            right_margin = 18;
            hsync_len = pclock->hsync / plen;
            upper_margin = 31;
            lower_margin = 14;
            vsync_len = interlace ? 3 : 4;
        } else {
            left_margin = var->left_margin;
            right_margin = var->right_margin;
            hsync_len = var->hsync_len;
            upper_margin = var->upper_margin;
            lower_margin = var->lower_margin;
            vsync_len = var->vsync_len;
            if (var->vmode & FB_VMODE_INTERLACED) {
                upper_margin = (upper_margin + 1) / 2;
                lower_margin = (lower_margin + 1) / 2;
                vsync_len = (vsync_len + 1) / 2;
            } else if (var->vmode & FB_VMODE_DOUBLE) {
                upper_margin *= 2;
                lower_margin *= 2;
                vsync_len *= 2;
            }
        }
    } else {            /* F_MON_VGA */
        if (bpp == 16)
            xstretch = 2;   /* Double pixel width only for hicolor */
        /* Default values are used for vert./hor. timing if no pixelclock given. */
        if (var->pixclock == 0) {
            int linesize;

            /* Choose master pixelclock depending on hor. timing */
            plen = 1 * xstretch;
            if ((plen * xres + f25.right + f25.hsync + f25.left) *
                fb_info.monspecs.hfmin < f25.f)
                pclock = &f25;
            else if ((plen * xres + f32.right + f32.hsync +
                  f32.left) * fb_info.monspecs.hfmin < f32.f)
                pclock = &f32;
            else if ((plen * xres + fext.right + fext.hsync +
                  fext.left) * fb_info.monspecs.hfmin < fext.f &&
                     fext.f)
                pclock = &fext;
            else
                return -EINVAL;

            left_margin = pclock->left / plen;
            right_margin = pclock->right / plen;
            hsync_len = pclock->hsync / plen;
            linesize = left_margin + xres + right_margin + hsync_len;
            upper_margin = 31;
            lower_margin = 11;
            vsync_len = 3;
        } else {
            /* Choose largest pixelclock <= wanted clock */
            int i;
            unsigned long pcl = ULONG_MAX;
            pclock = 0;
            for (i = 1; i <= 4; i *= 2) {
                if (f25.t * i >= var->pixclock &&
                    f25.t * i < pcl) {
                    pcl = f25.t * i;
                    pclock = &f25;
                }
                if (f32.t * i >= var->pixclock &&
                    f32.t * i < pcl) {
                    pcl = f32.t * i;
                    pclock = &f32;
                }
                if (fext.t && fext.t * i >= var->pixclock &&
                    fext.t * i < pcl) {
                    pcl = fext.t * i;
                    pclock = &fext;
                }
            }
            if (!pclock)
                return -EINVAL;
            plen = pcl / pclock->t;

            left_margin = var->left_margin;
            right_margin = var->right_margin;
            hsync_len = var->hsync_len;
            upper_margin = var->upper_margin;
            lower_margin = var->lower_margin;
            vsync_len = var->vsync_len;
            /* Internal unit is [single lines per (half-)frame] */
            if (var->vmode & FB_VMODE_INTERLACED) {
                /* # lines in half frame */
                /* External unit is [lines per full frame] */
                upper_margin = (upper_margin + 1) / 2;
                lower_margin = (lower_margin + 1) / 2;
                vsync_len = (vsync_len + 1) / 2;
            } else if (var->vmode & FB_VMODE_DOUBLE) {
                /* External unit is [double lines per frame] */
                upper_margin *= 2;
                lower_margin *= 2;
                vsync_len *= 2;
            }
        }
        if (pclock == &fext)
            longoffset = 1; /* VIDEL doesn't synchronize on short offset */
    }
    /* Is video bus bandwidth (32MB/s) too low for this resolution? */
    /* this is definitely wrong if bus clock != 32MHz */
    if (pclock->f / plen / 8 * bpp > 32000000L)
        return -EINVAL;

    if (vsync_len < 1)
        vsync_len = 1;

    /* include sync lengths in right/lower margin for all calculations */
    right_margin += hsync_len;
    lower_margin += vsync_len;

    /* ! In all calculations of margins we use # of lines in half frame
     * (which is a full frame in non-interlace mode), so we can switch
     * between interlace and non-interlace without messing around
     * with these.
     */
again:
    /* Set base_offset 128 and video bus width */
    par->hw.falcon.vid_control = mon_type | f030_bus_width;
    if (!longoffset)
        par->hw.falcon.vid_control |= VCO_SHORTOFFS;    /* base_offset 64 */
    if (var->sync & FB_SYNC_HOR_HIGH_ACT)
        par->hw.falcon.vid_control |= VCO_HSYPOS;
    if (var->sync & FB_SYNC_VERT_HIGH_ACT)
        par->hw.falcon.vid_control |= VCO_VSYPOS;
    /* Pixelclock */
    par->hw.falcon.vid_control |= pclock->control_mask;
    /* External or internal clock */
    par->hw.falcon.sync = pclock->sync_mask | 0x2;
    /* Pixellength and prescale */
    par->hw.falcon.vid_mode = (2 / plen) << 2;
    if (doubleline)
        par->hw.falcon.vid_mode |= VMO_DOUBLE;
    if (interlace)
        par->hw.falcon.vid_mode |= VMO_INTER;

    /*********************
     * Horizontal timing: unit = [master clock cycles]
     * unit of hxx-registers: [master clock cycles * prescale]
     * Hxx-registers are 9 bit wide
     *
     * 1 line = ((hht + 2) * 2 * prescale) clock cycles
     *
     * graphic output = hdb & 0x200 ?
     *        ((hht + 2) * 2 - hdb + hde) * prescale - hdboff + hdeoff:
     *        (hht + 2  - hdb + hde) * prescale - hdboff + hdeoff
     * (this must be a multiple of plen*128/bpp, on VGA pixels
     *  to the right may be cut off with a bigger right margin)
     *
     * start of graphics relative to start of 1st halfline = hdb & 0x200 ?
     *        (hdb - hht - 2) * prescale + hdboff :
     *        hdb * prescale + hdboff
     *
     * end of graphics relative to start of 1st halfline =
     *        (hde + hht + 2) * prescale + hdeoff
     *********************/
    /* Calculate VIDEL registers */
{
    prescale = hxx_prescale(&par->hw.falcon);
    base_off = par->hw.falcon.vid_control & VCO_SHORTOFFS ? 64 : 128;

    /* Offsets depend on video mode */
    /* Offsets are in clock cycles, divide by prescale to
     * calculate hd[be]-registers
     */
    if (par->hw.falcon.f_shift & 0x100) {
        align = 1;
        hde_off = 0;
        hdb_off = (base_off + 16 * plen) + prescale;
    } else {
        align = 128 / bpp;
        hde_off = ((128 / bpp + 2) * plen);
        if (par->hw.falcon.ste_mode)
            hdb_off = (64 + base_off + (128 / bpp + 2) * plen) + prescale;
        else
            hdb_off = (base_off + (128 / bpp + 18) * plen) + prescale;
    }

    gstart = (prescale / 2 + plen * left_margin) / prescale;
    /* gend1 is for hde (gend-gstart multiple of align), shifter's xres */
    gend1 = gstart + roundup(xres, align) * plen / prescale;
    /* gend2 is for hbb, visible xres (rest to gend1 is cut off by hblank) */
    gend2 = gstart + xres * plen / prescale;
    par->HHT = plen * (left_margin + xres + right_margin) /
               (2 * prescale) - 2;
/*  par->HHT = (gend2 + plen * right_margin / prescale) / 2 - 2;*/

    par->HDB = gstart - hdb_off / prescale;
    par->HBE = gstart;
    if (par->HDB < 0)
        par->HDB += par->HHT + 2 + 0x200;
    par->HDE = gend1 - par->HHT - 2 - hde_off / prescale;
    par->HBB = gend2 - par->HHT - 2;
#if 0
    /* One more Videl constraint: data fetch of two lines must not overlap */
    if ((par->HDB & 0x200) && (par->HDB & ~0x200) - par->HDE <= 5) {
        /* if this happens increase margins, decrease hfreq. */
    }
#endif
    if (hde_off % prescale)
        par->HBB++;     /* compensate for non matching hde and hbb */
    par->HSS = par->HHT + 2 - plen * hsync_len / prescale;
    if (par->HSS < par->HBB)
        par->HSS = par->HBB;
}

    /*  check hor. frequency */
    hfreq = pclock->f / ((par->HHT + 2) * prescale * 2);
    if (hfreq > fb_info.monspecs.hfmax && mon_type != F_MON_VGA) {
        /* ++guenther:   ^^^^^^^^^^^^^^^^^^^ can't remember why I did this */
        /* Too high -> enlarge margin */
        left_margin += 1;
        right_margin += 1;
        goto again;
    }
    if (hfreq > fb_info.monspecs.hfmax || hfreq < fb_info.monspecs.hfmin)
        return -EINVAL;

    /* Vxx-registers */
    /* All Vxx must be odd in non-interlace, since frame starts in the middle
     * of the first displayed line!
     * One frame consists of VFT+1 half lines. VFT+1 must be even in
     * non-interlace, odd in interlace mode for synchronisation.
     * Vxx-registers are 11 bit wide
     */
    par->VBE = (upper_margin * 2 + 1); /* must begin on odd halfline */
    par->VDB = par->VBE;
    par->VDE = yres;
    if (!interlace)
        par->VDE <<= 1;
    if (doubleline)
        par->VDE <<= 1;     /* VDE now half lines per (half-)frame */
    par->VDE += par->VDB;
    par->VBB = par->VDE;
    par->VFT = par->VBB + (lower_margin * 2 - 1) - 1;
    par->VSS = par->VFT + 1 - (vsync_len * 2 - 1);
    /* vbb,vss,vft must be even in interlace mode */
    if (interlace) {
        par->VBB++;
        par->VSS++;
        par->VFT++;
    }

    /* V-frequency check, hope I didn't create any loop here. */
    /* Interlace and doubleline are mutually exclusive. */
    vfreq = (hfreq * 2) / (par->VFT + 1);
    if (vfreq > fb_info.monspecs.vfmax && !doubleline && !interlace) {
        /* Too high -> try again with doubleline */
        doubleline = 1;
        goto again;
    } else if (vfreq < fb_info.monspecs.vfmin && !interlace && !doubleline) {
        /* Too low -> try again with interlace */
        interlace = 1;
        goto again;
    } else if (vfreq < fb_info.monspecs.vfmin && doubleline) {
        /* Doubleline too low -> clear doubleline and enlarge margins */
        int lines;
        doubleline = 0;
        for (lines = 0;
             (hfreq * 2) / (par->VFT + 1 + 4 * lines - 2 * yres) >
             fb_info.monspecs.vfmax;
             lines++)
            ;
        upper_margin += lines;
        lower_margin += lines;
        goto again;
    } else if (vfreq > fb_info.monspecs.vfmax && doubleline) {
        /* Doubleline too high -> enlarge margins */
        int lines;
        for (lines = 0;
             (hfreq * 2) / (par->VFT + 1 + 4 * lines) >
             fb_info.monspecs.vfmax;
             lines += 2)
            ;
        upper_margin += lines;
        lower_margin += lines;
        goto again;
    } else if (vfreq > fb_info.monspecs.vfmax && interlace) {
        /* Interlace, too high -> enlarge margins */
        int lines;
        for (lines = 0;
             (hfreq * 2) / (par->VFT + 1 + 4 * lines) >
             fb_info.monspecs.vfmax;
             lines++)
            ;
        upper_margin += lines;
        lower_margin += lines;
        goto again;
    } else if (vfreq < fb_info.monspecs.vfmin ||
           vfreq > fb_info.monspecs.vfmax)
        return -EINVAL;

set_screen_base:
    linelen = xres_virtual * bpp / 8;
    if (yres_virtual * linelen > screen_len && screen_len)
        return -EINVAL;
    if (yres * linelen > screen_len && screen_len)
        return -EINVAL;
    if (var->yoffset + yres > yres_virtual && yres_virtual)
        return -EINVAL;
    par->yres_virtual = yres_virtual;
    par->screen_base = screen_base + var->yoffset * linelen;
    par->hw.falcon.xoffset = 0;

    par->next_line = linelen;

    return 0;
}

static int falcon_encode_var(struct fb_var_screeninfo *var,
                 struct atafb_par *par)
{
/* !!! only for VGA !!! */
    int linelen;
    int prescale, plen;
    int hdb_off, hde_off, base_off;
    struct falcon_hw *hw = &par->hw.falcon;

    memset(var, 0, sizeof(struct fb_var_screeninfo));
    /* possible frequencies: 25.175 or 32MHz */
    var->pixclock = hw->sync & 0x1 ? fext.t :
                    hw->vid_control & VCO_CLOCK25 ? f25.t : f32.t;

    var->height = -1;
    var->width = -1;

    var->sync = 0;
    if (hw->vid_control & VCO_HSYPOS)
        var->sync |= FB_SYNC_HOR_HIGH_ACT;
    if (hw->vid_control & VCO_VSYPOS)
        var->sync |= FB_SYNC_VERT_HIGH_ACT;

    var->vmode = FB_VMODE_NONINTERLACED;
    if (hw->vid_mode & VMO_INTER)
        var->vmode |= FB_VMODE_INTERLACED;
    if (hw->vid_mode & VMO_DOUBLE)
        var->vmode |= FB_VMODE_DOUBLE;

    /* visible y resolution:
     * Graphics display starts at line VDB and ends at line
     * VDE. If interlace mode off unit of VC-registers is
     * half lines, else lines.
     */
    var->yres = hw->vde - hw->vdb;
    if (!(var->vmode & FB_VMODE_INTERLACED))
        var->yres >>= 1;
    if (var->vmode & FB_VMODE_DOUBLE)
        var->yres >>= 1;

    /*
     * to get bpp, we must examine f_shift and st_shift.
     * f_shift is valid if any of bits no. 10, 8 or 4
     * is set. Priority in f_shift is: 10 ">" 8 ">" 4, i.e.
     * if bit 10 set then bit 8 and bit 4 don't care...
     * If all these bits are 0 get display depth from st_shift
     * (as for ST and STE)
     */
    if (hw->f_shift & 0x400)    /* 2 colors */
        var->bits_per_pixel = 1;
    else if (hw->f_shift & 0x100)   /* hicolor */
        var->bits_per_pixel = 16;
    else if (hw->f_shift & 0x010)   /* 8 bitplanes */
        var->bits_per_pixel = 8;
    else if (hw->st_shift == 0)
        var->bits_per_pixel = 4;
    else if (hw->st_shift == 0x100)
        var->bits_per_pixel = 2;
    else                /* if (hw->st_shift == 0x200) */
        var->bits_per_pixel = 1;

    var->xres = hw->line_width * 16 / var->bits_per_pixel;
    var->xres_virtual = var->xres + hw->line_offset * 16 / var->bits_per_pixel;
    if (hw->xoffset)
        var->xres_virtual += 16;

    if (var->bits_per_pixel == 16) {
        var->red.offset = 11;
        var->red.length = 5;
        var->red.msb_right = 0;
        var->green.offset = 5;
        var->green.length = 6;
        var->green.msb_right = 0;
        var->blue.offset = 0;
        var->blue.length = 5;
        var->blue.msb_right = 0;
    } else {
        var->red.offset = 0;
        var->red.length = hw->ste_mode ? 4 : 6;
        if (var->red.length > var->bits_per_pixel)
            var->red.length = var->bits_per_pixel;
        var->red.msb_right = 0;
        var->grayscale = 0;
        var->blue = var->green = var->red;
    }
    var->transp.offset = 0;
    var->transp.length = 0;
    var->transp.msb_right = 0;

    linelen = var->xres_virtual * var->bits_per_pixel / 8;
    if (screen_len) {
        if (par->yres_virtual)
            var->yres_virtual = par->yres_virtual;
        else
            /* yres_virtual == 0 means use maximum */
            var->yres_virtual = screen_len / linelen;
    } else {
        if (hwscroll < 0)
            var->yres_virtual = 2 * var->yres;
        else
            var->yres_virtual = var->yres + hwscroll * 16;
    }
    var->xoffset = 0;       /* TODO change this */

    /* hdX-offsets */
    prescale = hxx_prescale(hw);
    plen = 4 >> (hw->vid_mode >> 2 & 0x3);
    base_off = hw->vid_control & VCO_SHORTOFFS ? 64 : 128;
    if (hw->f_shift & 0x100) {
        hde_off = 0;
        hdb_off = (base_off + 16 * plen) + prescale;
    } else {
        hde_off = ((128 / var->bits_per_pixel + 2) * plen);
        if (hw->ste_mode)
            hdb_off = (64 + base_off + (128 / var->bits_per_pixel + 2) * plen)
                     + prescale;
        else
            hdb_off = (base_off + (128 / var->bits_per_pixel + 18) * plen)
                     + prescale;
    }

    /* Right margin includes hsync */
    var->left_margin = hdb_off + prescale * ((hw->hdb & 0x1ff) -
                       (hw->hdb & 0x200 ? 2 + hw->hht : 0));
    if (hw->ste_mode || mon_type != F_MON_VGA)
        var->right_margin = prescale * (hw->hht + 2 - hw->hde) - hde_off;
    else
        /* can't use this in ste_mode, because hbb is +1 off */
        var->right_margin = prescale * (hw->hht + 2 - hw->hbb);
    var->hsync_len = prescale * (hw->hht + 2 - hw->hss);

    /* Lower margin includes vsync */
    var->upper_margin = hw->vdb / 2;    /* round down to full lines */
    var->lower_margin = (hw->vft + 1 - hw->vde + 1) / 2;    /* round up */
    var->vsync_len = (hw->vft + 1 - hw->vss + 1) / 2;   /* round up */
    if (var->vmode & FB_VMODE_INTERLACED) {
        var->upper_margin *= 2;
        var->lower_margin *= 2;
        var->vsync_len *= 2;
    } else if (var->vmode & FB_VMODE_DOUBLE) {
        var->upper_margin = (var->upper_margin + 1) / 2;
        var->lower_margin = (var->lower_margin + 1) / 2;
        var->vsync_len = (var->vsync_len + 1) / 2;
    }

    var->pixclock *= plen;
    var->left_margin /= plen;
    var->right_margin /= plen;
    var->hsync_len /= plen;

    var->right_margin -= var->hsync_len;
    var->lower_margin -= var->vsync_len;

    if (screen_base)
        var->yoffset = (par->screen_base - screen_base) / linelen;
    else
        var->yoffset = 0;
    var->nonstd = 0;        /* what is this for? */
    var->activate = 0;
    return 0;
}

static int f_change_mode;
static struct falcon_hw f_new_mode;
static int f_pan_display;

static void falcon_get_par(struct atafb_par *par)
{
    unsigned long addr;
    struct falcon_hw *hw = &par->hw.falcon;

    hw->line_width = shifter_f030.scn_width;
    hw->line_offset = shifter_f030.off_next;
    hw->st_shift = videl.st_shift & 0x300;
    hw->f_shift = videl.f_shift;
    hw->vid_control = videl.control;
    hw->vid_mode = videl.mode;
    hw->sync = shifter.syncmode & 0x1;
    hw->xoffset = videl.xoffset & 0xf;
    hw->hht = videl.hht;
    hw->hbb = videl.hbb;
    hw->hbe = videl.hbe;
    hw->hdb = videl.hdb;
    hw->hde = videl.hde;
    hw->hss = videl.hss;
    hw->vft = videl.vft;
    hw->vbb = videl.vbb;
    hw->vbe = videl.vbe;
    hw->vdb = videl.vdb;
    hw->vde = videl.vde;
    hw->vss = videl.vss;

    addr = (shifter.bas_hi & 0xff) << 16 |
           (shifter.bas_md & 0xff) << 8  |
           (shifter.bas_lo & 0xff);
    par->screen_base = phys_to_virt(addr);

    /* derived parameters */
    hw->ste_mode = (hw->f_shift & 0x510) == 0 && hw->st_shift == 0x100;
    hw->mono = (hw->f_shift & 0x400) ||
               ((hw->f_shift & 0x510) == 0 && hw->st_shift == 0x200);
}

static void falcon_set_par(struct atafb_par *par)
{
    f_change_mode = 0;

    /* only set screen_base if really necessary */
    if (current_par.screen_base != par->screen_base)
        fbhw->set_screen_base(par->screen_base);

    /* Don't touch any other registers if we keep the default resolution */
    if (DontCalcRes)
        return;

    /* Tell vbl-handler to change video mode.
     * We change modes only on next VBL, to avoid desynchronisation
     * (a shift to the right and wrap around by a random number of pixels
     * in all monochrome modes).
     * This seems to work on my Falcon.
     */
    f_new_mode = par->hw.falcon;
    f_change_mode = 1;
}

static irqreturn_t falcon_vbl_switcher(int irq, void *dummy)
{
    struct falcon_hw *hw = &f_new_mode;

    if (f_change_mode) {
        f_change_mode = 0;

        if (hw->sync & 0x1) {
            /* Enable external pixelclock. This code only for ScreenWonder */
            *(volatile unsigned short *)0xffff9202 = 0xffbf;
        } else {
            /* Turn off external clocks. Read sets all output bits to 1. */
            *(volatile unsigned short *)0xffff9202;
        }
        shifter.syncmode = hw->sync;

        videl.hht = hw->hht;
        videl.hbb = hw->hbb;
        videl.hbe = hw->hbe;
        videl.hdb = hw->hdb;
        videl.hde = hw->hde;
        videl.hss = hw->hss;
        videl.vft = hw->vft;
        videl.vbb = hw->vbb;
        videl.vbe = hw->vbe;
        videl.vdb = hw->vdb;
        videl.vde = hw->vde;
        videl.vss = hw->vss;

        videl.f_shift = 0;  /* write enables Falcon palette, 0: 4 planes */
        if (hw->ste_mode) {
            videl.st_shift = hw->st_shift;  /* write enables STE palette */
        } else {
            /* IMPORTANT:
             * set st_shift 0, so we can tell the screen-depth if f_shift == 0.
             * Writing 0 to f_shift enables 4 plane Falcon mode but
             * doesn't set st_shift. st_shift != 0 (!= 4planes) is impossible
             * with Falcon palette.
             */
            videl.st_shift = 0;
            /* now back to Falcon palette mode */
            videl.f_shift = hw->f_shift;
        }
        /* writing to st_shift changed scn_width and vid_mode */
        videl.xoffset = hw->xoffset;
        shifter_f030.scn_width = hw->line_width;
        shifter_f030.off_next = hw->line_offset;
        videl.control = hw->vid_control;
        videl.mode = hw->vid_mode;
    }
    if (f_pan_display) {
        f_pan_display = 0;
        videl.xoffset = current_par.hw.falcon.xoffset;
        shifter_f030.off_next = current_par.hw.falcon.line_offset;
    }
    return IRQ_HANDLED;
}

static int falcon_pan_display(struct fb_var_screeninfo *var,
                  struct fb_info *info)
{
    struct atafb_par *par = (struct atafb_par *)info->par;

    int xoffset;
    int bpp = info->var.bits_per_pixel;

    if (bpp == 1)
        var->xoffset = up(var->xoffset, 32);
    if (bpp != 16)
        par->hw.falcon.xoffset = var->xoffset & 15;
    else {
        par->hw.falcon.xoffset = 0;
        var->xoffset = up(var->xoffset, 2);
    }
    par->hw.falcon.line_offset = bpp *
        (info->var.xres_virtual - info->var.xres) / 16;
    if (par->hw.falcon.xoffset)
        par->hw.falcon.line_offset -= bpp;
    xoffset = var->xoffset - par->hw.falcon.xoffset;

    par->screen_base = screen_base +
            (var->yoffset * info->var.xres_virtual + xoffset) * bpp / 8;
    if (fbhw->set_screen_base)
        fbhw->set_screen_base(par->screen_base);
    else
        return -EINVAL;     /* shouldn't happen */
    f_pan_display = 1;
    return 0;
}

static int falcon_setcolreg(unsigned int regno, unsigned int red,
                unsigned int green, unsigned int blue,
                unsigned int transp, struct fb_info *info)
{
    if (regno > 255)
        return 1;
    f030_col[regno] = (((red & 0xfc00) << 16) |
               ((green & 0xfc00) << 8) |
               ((blue & 0xfc00) >> 8));
    if (regno < 16) {
        shifter_tt.color_reg[regno] =
            (((red & 0xe000) >> 13) | ((red & 0x1000) >> 12) << 8) |
            (((green & 0xe000) >> 13) | ((green & 0x1000) >> 12) << 4) |
            ((blue & 0xe000) >> 13) | ((blue & 0x1000) >> 12);
        ((u32 *)info->pseudo_palette)[regno] = ((red & 0xf800) |
                               ((green & 0xfc00) >> 5) |
                               ((blue & 0xf800) >> 11));
    }
    return 0;
}

static int falcon_blank(int blank_mode)
{
    /* ++guenther: we can switch off graphics by changing VDB and VDE,
     * so VIDEL doesn't hog the bus while saving.
     * (this may affect usleep()).
     */
    int vdb, vss, hbe, hss;

    if (mon_type == F_MON_SM)   /* this doesn't work on SM124 */
        return 1;

    vdb = current_par.VDB;
    vss = current_par.VSS;
    hbe = current_par.HBE;
    hss = current_par.HSS;

    if (blank_mode >= 1) {
        /* disable graphics output (this speeds up the CPU) ... */
        vdb = current_par.VFT + 1;
        /* ... and blank all lines */
        hbe = current_par.HHT + 2;
    }
    /* use VESA suspend modes on VGA monitors */
    if (mon_type == F_MON_VGA) {
        if (blank_mode == 2 || blank_mode == 4)
            vss = current_par.VFT + 1;
        if (blank_mode == 3 || blank_mode == 4)
            hss = current_par.HHT + 2;
    }

    videl.vdb = vdb;
    videl.vss = vss;
    videl.hbe = hbe;
    videl.hss = hss;

    return 0;
}

static int falcon_detect(void)
{
    struct atafb_par par;
    unsigned char fhw;

    /* Determine connected monitor and set monitor parameters */
    fhw = *(unsigned char *)0xffff8006;
    mon_type = fhw >> 6 & 0x3;
    /* bit 1 of fhw: 1=32 bit ram bus, 0=16 bit */
    f030_bus_width = fhw << 6 & 0x80;
    switch (mon_type) {
    case F_MON_SM:
        fb_info.monspecs.vfmin = 70;
        fb_info.monspecs.vfmax = 72;
        fb_info.monspecs.hfmin = 35713;
        fb_info.monspecs.hfmax = 35715;
        break;
    case F_MON_SC:
    case F_MON_TV:
        /* PAL...NTSC */
        fb_info.monspecs.vfmin = 49;    /* not 50, since TOS defaults to 49.9x Hz */
        fb_info.monspecs.vfmax = 60;
        fb_info.monspecs.hfmin = 15620;
        fb_info.monspecs.hfmax = 15755;
        break;
    }
    /* initialize hsync-len */
    f25.hsync = h_syncs[mon_type] / f25.t;
    f32.hsync = h_syncs[mon_type] / f32.t;
    if (fext.t)
        fext.hsync = h_syncs[mon_type] / fext.t;

    falcon_get_par(&par);
    falcon_encode_var(&atafb_predefined[0], &par);

    /* Detected mode is always the "autodetect" slot */
    return 1;
}

#endif /* ATAFB_FALCON */

/* ------------------- ST(E) specific functions ---------------------- */

#ifdef ATAFB_STE

static int stste_encode_fix(struct fb_fix_screeninfo *fix,
                struct atafb_par *par)
{
    int mode;

    strcpy(fix->id, "Atari Builtin");
    fix->smem_start = (unsigned long)real_screen_base;
    fix->smem_len = screen_len;
    fix->type = FB_TYPE_INTERLEAVED_PLANES;
    fix->type_aux = 2;
    fix->visual = FB_VISUAL_PSEUDOCOLOR;
    mode = par->hw.st.mode & 3;
    if (mode == ST_HIGH) {
        fix->type = FB_TYPE_PACKED_PIXELS;
        fix->type_aux = 0;
        fix->visual = FB_VISUAL_MONO10;
    }
    if (ATARIHW_PRESENT(EXTD_SHIFTER)) {
        fix->xpanstep = 16;
        fix->ypanstep = 1;
    } else {
        fix->xpanstep = 0;
        fix->ypanstep = 0;
    }
    fix->ywrapstep = 0;
    fix->line_length = par->next_line;
    fix->accel = FB_ACCEL_ATARIBLITT;
    return 0;
}

static int stste_decode_var(struct fb_var_screeninfo *var,
                struct atafb_par *par)
{
    int xres = var->xres;
    int yres = var->yres;
    int bpp = var->bits_per_pixel;
    int linelen;
    int yres_virtual = var->yres_virtual;

    if (mono_moni) {
        if (bpp > 1 || xres > sttt_xres || yres > st_yres)
            return -EINVAL;
        par->hw.st.mode = ST_HIGH;
        xres = sttt_xres;
        yres = st_yres;
        bpp = 1;
    } else {
        if (bpp > 4 || xres > sttt_xres || yres > st_yres)
            return -EINVAL;
        if (bpp > 2) {
            if (xres > sttt_xres / 2 || yres > st_yres / 2)
                return -EINVAL;
            par->hw.st.mode = ST_LOW;
            xres = sttt_xres / 2;
            yres = st_yres / 2;
            bpp = 4;
        } else if (bpp > 1) {
            if (xres > sttt_xres || yres > st_yres / 2)
                return -EINVAL;
            par->hw.st.mode = ST_MID;
            xres = sttt_xres;
            yres = st_yres / 2;
            bpp = 2;
        } else
            return -EINVAL;
    }
    if (yres_virtual <= 0)
        yres_virtual = 0;
    else if (yres_virtual < yres)
        yres_virtual = yres;
    if (var->sync & FB_SYNC_EXT)
        par->hw.st.sync = (par->hw.st.sync & ~1) | 1;
    else
        par->hw.st.sync = (par->hw.st.sync & ~1);
    linelen = xres * bpp / 8;
    if (yres_virtual * linelen > screen_len && screen_len)
        return -EINVAL;
    if (yres * linelen > screen_len && screen_len)
        return -EINVAL;
    if (var->yoffset + yres > yres_virtual && yres_virtual)
        return -EINVAL;
    par->yres_virtual = yres_virtual;
    par->screen_base = screen_base + var->yoffset * linelen;
    par->next_line = linelen;
    return 0;
}

static int stste_encode_var(struct fb_var_screeninfo *var,
                struct atafb_par *par)
{
    int linelen;
    memset(var, 0, sizeof(struct fb_var_screeninfo));
    var->red.offset = 0;
    var->red.length = ATARIHW_PRESENT(EXTD_SHIFTER) ? 4 : 3;
    var->red.msb_right = 0;
    var->grayscale = 0;

    var->pixclock = 31041;
    var->left_margin = 120;     /* these are incorrect */
    var->right_margin = 100;
    var->upper_margin = 8;
    var->lower_margin = 16;
    var->hsync_len = 140;
    var->vsync_len = 30;

    var->height = -1;
    var->width = -1;

    if (!(par->hw.st.sync & 1))
        var->sync = 0;
    else
        var->sync = FB_SYNC_EXT;

    switch (par->hw.st.mode & 3) {
    case ST_LOW:
        var->xres = sttt_xres / 2;
        var->yres = st_yres / 2;
        var->bits_per_pixel = 4;
        break;
    case ST_MID:
        var->xres = sttt_xres;
        var->yres = st_yres / 2;
        var->bits_per_pixel = 2;
        break;
    case ST_HIGH:
        var->xres = sttt_xres;
        var->yres = st_yres;
        var->bits_per_pixel = 1;
        break;
    }
    var->blue = var->green = var->red;
    var->transp.offset = 0;
    var->transp.length = 0;
    var->transp.msb_right = 0;
    var->xres_virtual = sttt_xres_virtual;
    linelen = var->xres_virtual * var->bits_per_pixel / 8;
    ovsc_addlen = linelen * (sttt_yres_virtual - st_yres);

    if (!use_hwscroll)
        var->yres_virtual = var->yres;
    else if (screen_len) {
        if (par->yres_virtual)
            var->yres_virtual = par->yres_virtual;
        else
            /* yres_virtual == 0 means use maximum */
            var->yres_virtual = screen_len / linelen;
    } else {
        if (hwscroll < 0)
            var->yres_virtual = 2 * var->yres;
        else
            var->yres_virtual = var->yres + hwscroll * 16;
    }
    var->xoffset = 0;
    if (screen_base)
        var->yoffset = (par->screen_base - screen_base) / linelen;
    else
        var->yoffset = 0;
    var->nonstd = 0;
    var->activate = 0;
    var->vmode = FB_VMODE_NONINTERLACED;
    return 0;
}

static void stste_get_par(struct atafb_par *par)
{
    unsigned long addr;
    par->hw.st.mode = shifter_tt.st_shiftmode;
    par->hw.st.sync = shifter.syncmode;
    addr = ((shifter.bas_hi & 0xff) << 16) |
           ((shifter.bas_md & 0xff) << 8);
    if (ATARIHW_PRESENT(EXTD_SHIFTER))
        addr |= (shifter.bas_lo & 0xff);
    par->screen_base = phys_to_virt(addr);
}

static void stste_set_par(struct atafb_par *par)
{
    shifter_tt.st_shiftmode = par->hw.st.mode;
    shifter.syncmode = par->hw.st.sync;
    /* only set screen_base if really necessary */
    if (current_par.screen_base != par->screen_base)
        fbhw->set_screen_base(par->screen_base);
}

static int stste_setcolreg(unsigned int regno, unsigned int red,
               unsigned int green, unsigned int blue,
               unsigned int transp, struct fb_info *info)
{
    if (regno > 15)
        return 1;
    red >>= 12;
    blue >>= 12;
    green >>= 12;
    if (ATARIHW_PRESENT(EXTD_SHIFTER))
        shifter_tt.color_reg[regno] =
            (((red & 0xe) >> 1) | ((red & 1) << 3) << 8) |
            (((green & 0xe) >> 1) | ((green & 1) << 3) << 4) |
            ((blue & 0xe) >> 1) | ((blue & 1) << 3);
    else
        shifter_tt.color_reg[regno] =
            ((red & 0xe) << 7) |
            ((green & 0xe) << 3) |
            ((blue & 0xe) >> 1);
    return 0;
}

static int stste_detect(void)
{
    struct atafb_par par;

    /* Determine the connected monitor: The DMA sound must be
     * disabled before reading the MFP GPIP, because the Sound
     * Done Signal and the Monochrome Detect are XORed together!
     */
    if (ATARIHW_PRESENT(PCM_8BIT)) {
        tt_dmasnd.ctrl = DMASND_CTRL_OFF;
        udelay(20);     /* wait a while for things to settle down */
    }
    mono_moni = (st_mfp.par_dt_reg & 0x80) == 0;

    stste_get_par(&par);
    stste_encode_var(&atafb_predefined[0], &par);

    if (!ATARIHW_PRESENT(EXTD_SHIFTER))
        use_hwscroll = 0;
    return 1;
}

static void stste_set_screen_base(void *s_base)
{
    unsigned long addr;
    addr = virt_to_phys(s_base);
    /* Setup Screen Memory */
    shifter.bas_hi = (unsigned char)((addr & 0xff0000) >> 16);
    shifter.bas_md = (unsigned char)((addr & 0x00ff00) >> 8);
    if (ATARIHW_PRESENT(EXTD_SHIFTER))
        shifter.bas_lo = (unsigned char)(addr & 0x0000ff);
}

#endif /* ATAFB_STE */

/* Switching the screen size should be done during vsync, otherwise
 * the margins may get messed up. This is a well known problem of
 * the ST's video system.
 *
 * Unfortunately there is hardly any way to find the vsync, as the
 * vertical blank interrupt is no longer in time on machines with
 * overscan type modifications.
 *
 * We can, however, use Timer B to safely detect the black shoulder,
 * but then we've got to guess an appropriate delay to find the vsync.
 * This might not work on every machine.
 *
 * martin_rogge @ ki.maus.de, 8th Aug 1995
 */

#define LINE_DELAY  (mono_moni ? 30 : 70)
#define SYNC_DELAY  (mono_moni ? 1500 : 2000)

/* SWITCH_ACIA may be used for Falcon (ScreenBlaster III internal!) */
static void st_ovsc_switch(void)
{
    unsigned long flags;
    register unsigned char old, new;

    if (!(atari_switches & ATARI_SWITCH_OVSC_MASK))
        return;
    local_irq_save(flags);

    st_mfp.tim_ct_b = 0x10;
    st_mfp.active_edge |= 8;
    st_mfp.tim_ct_b = 0;
    st_mfp.tim_dt_b = 0xf0;
    st_mfp.tim_ct_b = 8;
    while (st_mfp.tim_dt_b > 1) /* TOS does it this way, don't ask why */
        ;
    new = st_mfp.tim_dt_b;
    do {
        udelay(LINE_DELAY);
        old = new;
        new = st_mfp.tim_dt_b;
    } while (old != new);
    st_mfp.tim_ct_b = 0x10;
    udelay(SYNC_DELAY);

    if (atari_switches & ATARI_SWITCH_OVSC_IKBD)
        acia.key_ctrl = ACIA_DIV64 | ACIA_D8N1S | ACIA_RHTID | ACIA_RIE;
    if (atari_switches & ATARI_SWITCH_OVSC_MIDI)
        acia.mid_ctrl = ACIA_DIV16 | ACIA_D8N1S | ACIA_RHTID;
    if (atari_switches & (ATARI_SWITCH_OVSC_SND6|ATARI_SWITCH_OVSC_SND7)) {
        sound_ym.rd_data_reg_sel = 14;
        sound_ym.wd_data = sound_ym.rd_data_reg_sel |
                   ((atari_switches & ATARI_SWITCH_OVSC_SND6) ? 0x40:0) |
                   ((atari_switches & ATARI_SWITCH_OVSC_SND7) ? 0x80:0);
    }
    local_irq_restore(flags);
}

/* ------------------- External Video ---------------------- */

#ifdef ATAFB_EXT

static int ext_encode_fix(struct fb_fix_screeninfo *fix, struct atafb_par *par)
{
    strcpy(fix->id, "Unknown Extern");
    fix->smem_start = (unsigned long)external_addr;
    fix->smem_len = PAGE_ALIGN(external_len);
    if (external_depth == 1) {
        fix->type = FB_TYPE_PACKED_PIXELS;
        /* The letters 'n' and 'i' in the "atavideo=external:" stand
         * for "normal" and "inverted", rsp., in the monochrome case */
        fix->visual =
            (external_pmode == FB_TYPE_INTERLEAVED_PLANES ||
             external_pmode == FB_TYPE_PACKED_PIXELS) ?
                FB_VISUAL_MONO10 : FB_VISUAL_MONO01;
    } else {
        /* Use STATIC if we don't know how to access color registers */
        int visual = external_vgaiobase ?
                     FB_VISUAL_PSEUDOCOLOR :
                     FB_VISUAL_STATIC_PSEUDOCOLOR;
        switch (external_pmode) {
        case -1:        /* truecolor */
            fix->type = FB_TYPE_PACKED_PIXELS;
            fix->visual = FB_VISUAL_TRUECOLOR;
            break;
        case FB_TYPE_PACKED_PIXELS:
            fix->type = FB_TYPE_PACKED_PIXELS;
            fix->visual = visual;
            break;
        case FB_TYPE_PLANES:
            fix->type = FB_TYPE_PLANES;
            fix->visual = visual;
            break;
        case FB_TYPE_INTERLEAVED_PLANES:
            fix->type = FB_TYPE_INTERLEAVED_PLANES;
            fix->type_aux = 2;
            fix->visual = visual;
            break;
        }
    }
    fix->xpanstep = 0;
    fix->ypanstep = 0;
    fix->ywrapstep = 0;
    fix->line_length = par->next_line;
    return 0;
}

static int ext_decode_var(struct fb_var_screeninfo *var, struct atafb_par *par)
{
    struct fb_var_screeninfo *myvar = &atafb_predefined[0];

    if (var->bits_per_pixel > myvar->bits_per_pixel ||
        var->xres > myvar->xres ||
        var->xres_virtual > myvar->xres_virtual ||
        var->yres > myvar->yres ||
        var->xoffset > 0 ||
        var->yoffset > 0)
        return -EINVAL;

    par->next_line = external_xres_virtual * external_depth / 8;
    return 0;
}

static int ext_encode_var(struct fb_var_screeninfo *var, struct atafb_par *par)
{
    memset(var, 0, sizeof(struct fb_var_screeninfo));
    var->red.offset = 0;
    var->red.length = (external_pmode == -1) ? external_depth / 3 :
            (external_vgaiobase ? external_bitspercol : 0);
    var->red.msb_right = 0;
    var->grayscale = 0;

    var->pixclock = 31041;
    var->left_margin = 120;     /* these are surely incorrect */
    var->right_margin = 100;
    var->upper_margin = 8;
    var->lower_margin = 16;
    var->hsync_len = 140;
    var->vsync_len = 30;

    var->height = -1;
    var->width = -1;

    var->sync = 0;

    var->xres = external_xres;
    var->yres = external_yres;
    var->xres_virtual = external_xres_virtual;
    var->bits_per_pixel = external_depth;

    var->blue = var->green = var->red;
    var->transp.offset = 0;
    var->transp.length = 0;
    var->transp.msb_right = 0;
    var->yres_virtual = var->yres;
    var->xoffset = 0;
    var->yoffset = 0;
    var->nonstd = 0;
    var->activate = 0;
    var->vmode = FB_VMODE_NONINTERLACED;
    return 0;
}

static void ext_get_par(struct atafb_par *par)
{
    par->screen_base = external_addr;
}

static void ext_set_par(struct atafb_par *par)
{
}

#define OUTB(port,val) \
    *((unsigned volatile char *) ((port)+external_vgaiobase)) = (val)
#define INB(port) \
    (*((unsigned volatile char *) ((port)+external_vgaiobase)))
#define DACDelay                \
    do {                    \
        unsigned char tmp = INB(0x3da); \
        tmp = INB(0x3da);           \
    } while (0)

static int ext_setcolreg(unsigned int regno, unsigned int red,
             unsigned int green, unsigned int blue,
             unsigned int transp, struct fb_info *info)
{
    unsigned char colmask = (1 << external_bitspercol) - 1;

    if (!external_vgaiobase)
        return 1;

    if (regno > 255)
        return 1;

    switch (external_card_type) {
    case IS_VGA:
        OUTB(0x3c8, regno);
        DACDelay;
        OUTB(0x3c9, red & colmask);
        DACDelay;
        OUTB(0x3c9, green & colmask);
        DACDelay;
        OUTB(0x3c9, blue & colmask);
        DACDelay;
        return 0;

    case IS_MV300:
        OUTB((MV300_reg[regno] << 2) + 1, red);
        OUTB((MV300_reg[regno] << 2) + 1, green);
        OUTB((MV300_reg[regno] << 2) + 1, blue);
        return 0;

    default:
        return 1;
    }
}

static int ext_detect(void)
{
    struct fb_var_screeninfo *myvar = &atafb_predefined[0];
    struct atafb_par dummy_par;

    myvar->xres = external_xres;
    myvar->xres_virtual = external_xres_virtual;
    myvar->yres = external_yres;
    myvar->bits_per_pixel = external_depth;
    ext_encode_var(myvar, &dummy_par);
    return 1;
}

#endif /* ATAFB_EXT */

/* ------ This is the same for most hardware types -------- */

static void set_screen_base(void *s_base)
{
    unsigned long addr;

    addr = virt_to_phys(s_base);
    /* Setup Screen Memory */
    shifter.bas_hi = (unsigned char)((addr & 0xff0000) >> 16);
    shifter.bas_md = (unsigned char)((addr & 0x00ff00) >> 8);
    shifter.bas_lo = (unsigned char)(addr & 0x0000ff);
}

static int pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
{
    struct atafb_par *par = (struct atafb_par *)info->par;

    if (!fbhw->set_screen_base ||
        (!ATARIHW_PRESENT(EXTD_SHIFTER) && var->xoffset))
        return -EINVAL;
    var->xoffset = up(var->xoffset, 16);
    par->screen_base = screen_base +
            (var->yoffset * info->var.xres_virtual + var->xoffset)
            * info->var.bits_per_pixel / 8;
    fbhw->set_screen_base(par->screen_base);
    return 0;
}

/* ------------ Interfaces to hardware functions ------------ */

#ifdef ATAFB_TT
static struct fb_hwswitch tt_switch = {
    .detect     = tt_detect,
    .encode_fix = tt_encode_fix,
    .decode_var = tt_decode_var,
    .encode_var = tt_encode_var,
    .get_par    = tt_get_par,
    .set_par    = tt_set_par,
    .set_screen_base = set_screen_base,
    .pan_display    = pan_display,
};
#endif

#ifdef ATAFB_FALCON
static struct fb_hwswitch falcon_switch = {
    .detect     = falcon_detect,
    .encode_fix = falcon_encode_fix,
    .decode_var = falcon_decode_var,
    .encode_var = falcon_encode_var,
    .get_par    = falcon_get_par,
    .set_par    = falcon_set_par,
    .set_screen_base = set_screen_base,
    .blank      = falcon_blank,
    .pan_display    = falcon_pan_display,
};
#endif

#ifdef ATAFB_STE
static struct fb_hwswitch st_switch = {
    .detect     = stste_detect,
    .encode_fix = stste_encode_fix,
    .decode_var = stste_decode_var,
    .encode_var = stste_encode_var,
    .get_par    = stste_get_par,
    .set_par    = stste_set_par,
    .set_screen_base = stste_set_screen_base,
    .pan_display    = pan_display
};
#endif

#ifdef ATAFB_EXT
static struct fb_hwswitch ext_switch = {
    .detect     = ext_detect,
    .encode_fix = ext_encode_fix,
    .decode_var = ext_decode_var,
    .encode_var = ext_encode_var,
    .get_par    = ext_get_par,
    .set_par    = ext_set_par,
};
#endif

static void ata_get_par(struct atafb_par *par)
{
    if (current_par_valid)
        *par = current_par;
    else
        fbhw->get_par(par);
}

static void ata_set_par(struct atafb_par *par)
{
    fbhw->set_par(par);
    current_par = *par;
    current_par_valid = 1;
}


/* =========================================================== */
/* ============== Hardware Independent Functions ============= */
/* =========================================================== */

/* used for hardware scrolling */

static int do_fb_set_var(struct fb_var_screeninfo *var, int isactive)
{
    int err, activate;
    struct atafb_par par;

    err = fbhw->decode_var(var, &par);
    if (err)
        return err;
    activate = var->activate;
    if (((var->activate & FB_ACTIVATE_MASK) == FB_ACTIVATE_NOW) && isactive)
        ata_set_par(&par);
    fbhw->encode_var(var, &par);
    var->activate = activate;
    return 0;
}

/* fbhw->encode_fix() must be called with fb_info->mm_lock held
 * if it is called after the register_framebuffer() - not a case here
 */
static int atafb_get_fix(struct fb_fix_screeninfo *fix, struct fb_info *info)
{
    struct atafb_par par;
    int err;
    // Get fix directly (case con == -1 before)??
    err = fbhw->decode_var(&info->var, &par);
    if (err)
        return err;
    memset(fix, 0, sizeof(struct fb_fix_screeninfo));
    err = fbhw->encode_fix(fix, &par);
    return err;
}

static int atafb_get_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
    struct atafb_par par;

    ata_get_par(&par);
    fbhw->encode_var(var, &par);

    return 0;
}

// No longer called by fbcon!
// Still called by set_var internally

static void atafb_set_disp(struct fb_info *info)
{
    atafb_get_var(&info->var, info);
    atafb_get_fix(&info->fix, info);

    info->screen_base = (void *)info->fix.smem_start;
}

static int atafb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
               u_int transp, struct fb_info *info)
{
    red >>= 8;
    green >>= 8;
    blue >>= 8;

    return info->fbops->fb_setcolreg(regno, red, green, blue, transp, info);
}

static int
atafb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
{
    int xoffset = var->xoffset;
    int yoffset = var->yoffset;
    int err;

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

    if (fbhw->pan_display) {
        err = fbhw->pan_display(var, info);
        if (err)
            return err;
    } else
        return -EINVAL;

    info->var.xoffset = xoffset;
    info->var.yoffset = yoffset;

    if (var->vmode & FB_VMODE_YWRAP)
        info->var.vmode |= FB_VMODE_YWRAP;
    else
        info->var.vmode &= ~FB_VMODE_YWRAP;

    return 0;
}

/*
 * generic drawing routines; imageblit needs updating for image depth > 1
 */

#if BITS_PER_LONG == 32
#define BYTES_PER_LONG  4
#define SHIFT_PER_LONG  5
#elif BITS_PER_LONG == 64
#define BYTES_PER_LONG  8
#define SHIFT_PER_LONG  6
#else
#define Please update me
#endif


static void atafb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
{
    struct atafb_par *par = (struct atafb_par *)info->par;
    int x2, y2;
    u32 width, height;

    if (!rect->width || !rect->height)
        return;

#ifdef ATAFB_FALCON
    if (info->var.bits_per_pixel == 16) {
        cfb_fillrect(info, rect);
        return;
    }
#endif

    /*
     * We could use hardware clipping but on many cards you get around
     * hardware clipping by writing to framebuffer directly.
     * */
    x2 = rect->dx + rect->width;
    y2 = rect->dy + rect->height;
    x2 = x2 < info->var.xres_virtual ? x2 : info->var.xres_virtual;
    y2 = y2 < info->var.yres_virtual ? y2 : info->var.yres_virtual;
    width = x2 - rect->dx;
    height = y2 - rect->dy;

    if (info->var.bits_per_pixel == 1)
        atafb_mfb_fillrect(info, par->next_line, rect->color,
                   rect->dy, rect->dx, height, width);
    else if (info->var.bits_per_pixel == 2)
        atafb_iplan2p2_fillrect(info, par->next_line, rect->color,
                    rect->dy, rect->dx, height, width);
    else if (info->var.bits_per_pixel == 4)
        atafb_iplan2p4_fillrect(info, par->next_line, rect->color,
                    rect->dy, rect->dx, height, width);
    else
        atafb_iplan2p8_fillrect(info, par->next_line, rect->color,
                    rect->dy, rect->dx, height, width);

    return;
}

static void atafb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
{
    struct atafb_par *par = (struct atafb_par *)info->par;
    int x2, y2;
    u32 dx, dy, sx, sy, width, height;
    int rev_copy = 0;

#ifdef ATAFB_FALCON
    if (info->var.bits_per_pixel == 16) {
        cfb_copyarea(info, area);
        return;
    }
#endif

    /* clip the destination */
    x2 = area->dx + area->width;
    y2 = area->dy + area->height;
    dx = area->dx > 0 ? area->dx : 0;
    dy = area->dy > 0 ? area->dy : 0;
    x2 = x2 < info->var.xres_virtual ? x2 : info->var.xres_virtual;
    y2 = y2 < info->var.yres_virtual ? y2 : info->var.yres_virtual;
    width = x2 - dx;
    height = y2 - dy;

    if (area->sx + dx < area->dx || area->sy + dy < area->dy)
        return;

    /* update sx,sy */
    sx = area->sx + (dx - area->dx);
    sy = area->sy + (dy - area->dy);

    /* the source must be completely inside the virtual screen */
    if (sx + width > info->var.xres_virtual ||
            sy + height > info->var.yres_virtual)
        return;

    if (dy > sy || (dy == sy && dx > sx)) {
        dy += height;
        sy += height;
        rev_copy = 1;
    }

    if (info->var.bits_per_pixel == 1)
        atafb_mfb_copyarea(info, par->next_line, sy, sx, dy, dx, height, width);
    else if (info->var.bits_per_pixel == 2)
        atafb_iplan2p2_copyarea(info, par->next_line, sy, sx, dy, dx, height, width);
    else if (info->var.bits_per_pixel == 4)
        atafb_iplan2p4_copyarea(info, par->next_line, sy, sx, dy, dx, height, width);
    else
        atafb_iplan2p8_copyarea(info, par->next_line, sy, sx, dy, dx, height, width);

    return;
}

static void atafb_imageblit(struct fb_info *info, const struct fb_image *image)
{
    struct atafb_par *par = (struct atafb_par *)info->par;
    int x2, y2;
    unsigned long *dst;
    int dst_idx;
    const char *src;
    u32 dx, dy, width, height, pitch;

#ifdef ATAFB_FALCON
    if (info->var.bits_per_pixel == 16) {
        cfb_imageblit(info, image);
        return;
    }
#endif

    /*
     * We could use hardware clipping but on many cards you get around
     * hardware clipping by writing to framebuffer directly like we are
     * doing here.
     */
    x2 = image->dx + image->width;
    y2 = image->dy + image->height;
    dx = image->dx;
    dy = image->dy;
    x2 = x2 < info->var.xres_virtual ? x2 : info->var.xres_virtual;
    y2 = y2 < info->var.yres_virtual ? y2 : info->var.yres_virtual;
    width = x2 - dx;
    height = y2 - dy;

    if (image->depth == 1) {
        // used for font data
        dst = (unsigned long *)
            ((unsigned long)info->screen_base & ~(BYTES_PER_LONG - 1));
        dst_idx = ((unsigned long)info->screen_base & (BYTES_PER_LONG - 1)) * 8;
        dst_idx += dy * par->next_line * 8 + dx;
        src = image->data;
        pitch = (image->width + 7) / 8;
        while (height--) {

            if (info->var.bits_per_pixel == 1)
                atafb_mfb_linefill(info, par->next_line,
                           dy, dx, width, src,
                           image->bg_color, image->fg_color);
            else if (info->var.bits_per_pixel == 2)
                atafb_iplan2p2_linefill(info, par->next_line,
                            dy, dx, width, src,
                            image->bg_color, image->fg_color);
            else if (info->var.bits_per_pixel == 4)
                atafb_iplan2p4_linefill(info, par->next_line,
                            dy, dx, width, src,
                            image->bg_color, image->fg_color);
            else
                atafb_iplan2p8_linefill(info, par->next_line,
                            dy, dx, width, src,
                            image->bg_color, image->fg_color);
            dy++;
            src += pitch;
        }
    } else {
        c2p_iplan2(info->screen_base, image->data, dx, dy, width,
               height, par->next_line, image->width,
               info->var.bits_per_pixel);
    }
}

static int
atafb_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
{
    switch (cmd) {
#ifdef FBCMD_GET_CURRENTPAR
    case FBCMD_GET_CURRENTPAR:
        if (copy_to_user((void *)arg, (void *)&current_par,
                 sizeof(struct atafb_par)))
            return -EFAULT;
        return 0;
#endif
#ifdef FBCMD_SET_CURRENTPAR
    case FBCMD_SET_CURRENTPAR:
        if (copy_from_user((void *)&current_par, (void *)arg,
                   sizeof(struct atafb_par)))
            return -EFAULT;
        ata_set_par(&current_par);
        return 0;
#endif
    }
    return -EINVAL;
}

/* (un)blank/poweroff
 * 0 = unblank
 * 1 = blank
 * 2 = suspend vsync
 * 3 = suspend hsync
 * 4 = off
 */
static int atafb_blank(int blank, struct fb_info *info)
{
    unsigned short black[16];
    struct fb_cmap cmap;
    if (fbhw->blank && !fbhw->blank(blank))
        return 1;
    if (blank) {
        memset(black, 0, 16 * sizeof(unsigned short));
        cmap.red = black;
        cmap.green = black;
        cmap.blue = black;
        cmap.transp = NULL;
        cmap.start = 0;
        cmap.len = 16;
        fb_set_cmap(&cmap, info);
    }
#if 0
    else
        do_install_cmap(info);
#endif
    return 0;
}

    /*
     * New fbcon interface ...
     */

     /* check var by decoding var into hw par, rounding if necessary,
      * then encoding hw par back into new, validated var */
static int atafb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
    int err;
    struct atafb_par par;

    /* Validate wanted screen parameters */
    // if ((err = ata_decode_var(var, &par)))
    err = fbhw->decode_var(var, &par);
    if (err)
        return err;

    /* Encode (possibly rounded) screen parameters */
    fbhw->encode_var(var, &par);
    return 0;
}

    /* actually set hw par by decoding var, then setting hardware from
     * hw par just decoded */
static int atafb_set_par(struct fb_info *info)
{
    struct atafb_par *par = (struct atafb_par *)info->par;

    /* Decode wanted screen parameters */
    fbhw->decode_var(&info->var, par);
    mutex_lock(&info->mm_lock);
    fbhw->encode_fix(&info->fix, par);
    mutex_unlock(&info->mm_lock);

    /* Set new videomode */
    ata_set_par(par);

    return 0;
}


static struct fb_ops atafb_ops = {
    .owner =    THIS_MODULE,
    .fb_check_var   = atafb_check_var,
    .fb_set_par = atafb_set_par,
    .fb_setcolreg   = atafb_setcolreg,
    .fb_blank = atafb_blank,
    .fb_pan_display = atafb_pan_display,
    .fb_fillrect    = atafb_fillrect,
    .fb_copyarea    = atafb_copyarea,
    .fb_imageblit   = atafb_imageblit,
    .fb_ioctl = atafb_ioctl,
};

static void check_default_par(int detected_mode)
{
    char default_name[10];
    int i;
    struct fb_var_screeninfo var;
    unsigned long min_mem;

    /* First try the user supplied mode */
    if (default_par) {
        var = atafb_predefined[default_par - 1];
        var.activate = FB_ACTIVATE_TEST;
        if (do_fb_set_var(&var, 1))
            default_par = 0;    /* failed */
    }
    /* Next is the autodetected one */
    if (!default_par) {
        var = atafb_predefined[detected_mode - 1]; /* autodetect */
        var.activate = FB_ACTIVATE_TEST;
        if (!do_fb_set_var(&var, 1))
            default_par = detected_mode;
    }
    /* If that also failed, try some default modes... */
    if (!default_par) {
        /* try default1, default2... */
        for (i = 1; i < 10; i++) {
            sprintf(default_name,"default%d", i);
            default_par = get_video_mode(default_name);
            if (!default_par)
                panic("can't set default video mode");
            var = atafb_predefined[default_par - 1];
            var.activate = FB_ACTIVATE_TEST;
            if (!do_fb_set_var(&var,1))
                break;  /* ok */
        }
    }
    min_mem = var.xres_virtual * var.yres_virtual * var.bits_per_pixel / 8;
    if (default_mem_req < min_mem)
        default_mem_req = min_mem;
}

#ifdef ATAFB_EXT
static void __init atafb_setup_ext(char *spec)
{
    int xres, xres_virtual, yres, depth, planes;
    unsigned long addr, len;
    char *p;

    /* Format is: <xres>;<yres>;<depth>;<plane organ.>;
     *            <screen mem addr>
     *        [;<screen mem length>[;<vgaiobase>[;<bits-per-col>[;<colorreg-type>
     *        [;<xres-virtual>]]]]]
     *
     * 09/23/97 Juergen
     * <xres_virtual>:  hardware's x-resolution (f.e. ProMST)
     *
     * Even xres_virtual is available, we neither support panning nor hw-scrolling!
     */
    p = strsep(&spec, ";");
    if (!p || !*p)
        return;
    xres_virtual = xres = simple_strtoul(p, NULL, 10);
    if (xres <= 0)
        return;

    p = strsep(&spec, ";");
    if (!p || !*p)
        return;
    yres = simple_strtoul(p, NULL, 10);
    if (yres <= 0)
        return;

    p = strsep(&spec, ";");
    if (!p || !*p)
        return;
    depth = simple_strtoul(p, NULL, 10);
    if (depth != 1 && depth != 2 && depth != 4 && depth != 8 &&
        depth != 16 && depth != 24)
        return;

    p = strsep(&spec, ";");
    if (!p || !*p)
        return;
    if (*p == 'i')
        planes = FB_TYPE_INTERLEAVED_PLANES;
    else if (*p == 'p')
        planes = FB_TYPE_PACKED_PIXELS;
    else if (*p == 'n')
        planes = FB_TYPE_PLANES;
    else if (*p == 't')
        planes = -1;        /* true color */
    else
        return;

    p = strsep(&spec, ";");
    if (!p || !*p)
        return;
    addr = simple_strtoul(p, NULL, 0);

    p = strsep(&spec, ";");
    if (!p || !*p)
        len = xres * yres * depth / 8;
    else
        len = simple_strtoul(p, NULL, 0);

    p = strsep(&spec, ";");
    if (p && *p)
        external_vgaiobase = simple_strtoul(p, NULL, 0);

    p = strsep(&spec, ";");
    if (p && *p) {
        external_bitspercol = simple_strtoul(p, NULL, 0);
        if (external_bitspercol > 8)
            external_bitspercol = 8;
        else if (external_bitspercol < 1)
            external_bitspercol = 1;
    }

    p = strsep(&spec, ";");
    if (p && *p) {
        if (!strcmp(p, "vga"))
            external_card_type = IS_VGA;
        if (!strcmp(p, "mv300"))
            external_card_type = IS_MV300;
    }

    p = strsep(&spec, ";");
    if (p && *p) {
        xres_virtual = simple_strtoul(p, NULL, 10);
        if (xres_virtual < xres)
            xres_virtual = xres;
        if (xres_virtual * yres * depth / 8 > len)
            len = xres_virtual * yres * depth / 8;
    }

    external_xres = xres;
    external_xres_virtual = xres_virtual;
    external_yres = yres;
    external_depth = depth;
    external_pmode = planes;
    external_addr = (void *)addr;
    external_len = len;

    if (external_card_type == IS_MV300) {
        switch (external_depth) {
        case 1:
            MV300_reg = MV300_reg_1bit;
            break;
        case 4:
            MV300_reg = MV300_reg_4bit;
            break;
        case 8:
            MV300_reg = MV300_reg_8bit;
            break;
        }
    }
}
#endif /* ATAFB_EXT */

static void __init atafb_setup_int(char *spec)
{
    /* Format to config extended internal video hardware like OverScan:
     * "internal:<xres>;<yres>;<xres_max>;<yres_max>;<offset>"
     * Explanation:
     * <xres>: x-resolution
     * <yres>: y-resolution
     * The following are only needed if you have an overscan which
     * needs a black border:
     * <xres_max>: max. length of a line in pixels your OverScan hardware would allow
     * <yres_max>: max. number of lines your OverScan hardware would allow
     * <offset>: Offset from physical beginning to visible beginning
     *    of screen in bytes
     */
    int xres;
    char *p;

    if (!(p = strsep(&spec, ";")) || !*p)
        return;
    xres = simple_strtoul(p, NULL, 10);
    if (!(p = strsep(&spec, ";")) || !*p)
        return;
    sttt_xres = xres;
    tt_yres = st_yres = simple_strtoul(p, NULL, 10);
    if ((p = strsep(&spec, ";")) && *p)
        sttt_xres_virtual = simple_strtoul(p, NULL, 10);
    if ((p = strsep(&spec, ";")) && *p)
        sttt_yres_virtual = simple_strtoul(p, NULL, 0);
    if ((p = strsep(&spec, ";")) && *p)
        ovsc_offset = simple_strtoul(p, NULL, 0);

    if (ovsc_offset || (sttt_yres_virtual != st_yres))
        use_hwscroll = 0;
}

#ifdef ATAFB_FALCON
static void __init atafb_setup_mcap(char *spec)
{
    char *p;
    int vmin, vmax, hmin, hmax;

    /* Format for monitor capabilities is: <Vmin>;<Vmax>;<Hmin>;<Hmax>
     * <V*> vertical freq. in Hz
     * <H*> horizontal freq. in kHz
     */
    if (!(p = strsep(&spec, ";")) || !*p)
        return;
    vmin = simple_strtoul(p, NULL, 10);
    if (vmin <= 0)
        return;
    if (!(p = strsep(&spec, ";")) || !*p)
        return;
    vmax = simple_strtoul(p, NULL, 10);
    if (vmax <= 0 || vmax <= vmin)
        return;
    if (!(p = strsep(&spec, ";")) || !*p)
        return;
    hmin = 1000 * simple_strtoul(p, NULL, 10);
    if (hmin <= 0)
        return;
    if (!(p = strsep(&spec, "")) || !*p)
        return;
    hmax = 1000 * simple_strtoul(p, NULL, 10);
    if (hmax <= 0 || hmax <= hmin)
        return;

    fb_info.monspecs.vfmin = vmin;
    fb_info.monspecs.vfmax = vmax;
    fb_info.monspecs.hfmin = hmin;
    fb_info.monspecs.hfmax = hmax;
}
#endif /* ATAFB_FALCON */

static void __init atafb_setup_user(char *spec)
{
    /* Format of user defined video mode is: <xres>;<yres>;<depth>
     */
    char *p;
    int xres, yres, depth, temp;

    p = strsep(&spec, ";");
    if (!p || !*p)
        return;
    xres = simple_strtoul(p, NULL, 10);
    p = strsep(&spec, ";");
    if (!p || !*p)
        return;
    yres = simple_strtoul(p, NULL, 10);
    p = strsep(&spec, "");
    if (!p || !*p)
        return;
    depth = simple_strtoul(p, NULL, 10);
    temp = get_video_mode("user0");
    if (temp) {
        default_par = temp;
        atafb_predefined[default_par - 1].xres = xres;
        atafb_predefined[default_par - 1].yres = yres;
        atafb_predefined[default_par - 1].bits_per_pixel = depth;
    }
}

int __init atafb_setup(char *options)
{
    char *this_opt;
    int temp;

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

    while ((this_opt = strsep(&options, ",")) != NULL) {
        if (!*this_opt)
            continue;
        if ((temp = get_video_mode(this_opt))) {
            default_par = temp;
            mode_option = this_opt;
        } else if (!strcmp(this_opt, "inverse"))
            inverse = 1;
        else if (!strncmp(this_opt, "hwscroll_", 9)) {
            hwscroll = simple_strtoul(this_opt + 9, NULL, 10);
            if (hwscroll < 0)
                hwscroll = 0;
            if (hwscroll > 200)
                hwscroll = 200;
        }
#ifdef ATAFB_EXT
        else if (!strcmp(this_opt, "mv300")) {
            external_bitspercol = 8;
            external_card_type = IS_MV300;
        } else if (!strncmp(this_opt, "external:", 9))
            atafb_setup_ext(this_opt + 9);
#endif
        else if (!strncmp(this_opt, "internal:", 9))
            atafb_setup_int(this_opt + 9);
#ifdef ATAFB_FALCON
        else if (!strncmp(this_opt, "eclock:", 7)) {
            fext.f = simple_strtoul(this_opt + 7, NULL, 10);
            /* external pixelclock in kHz --> ps */
            fext.t = 1000000000 / fext.f;
            fext.f *= 1000;
        } else if (!strncmp(this_opt, "monitorcap:", 11))
            atafb_setup_mcap(this_opt + 11);
#endif
        else if (!strcmp(this_opt, "keep"))
            DontCalcRes = 1;
        else if (!strncmp(this_opt, "R", 1))
            atafb_setup_user(this_opt + 1);
    }
    return 0;
}

int __init atafb_init(void)
{
    int pad, detected_mode, error;
    unsigned int defmode = 0;
    unsigned long mem_req;

#ifndef MODULE
    char *option = NULL;

    if (fb_get_options("atafb", &option))
        return -ENODEV;
    atafb_setup(option);
#endif
    printk("atafb_init: start\n");

    if (!MACH_IS_ATARI)
        return -ENODEV;

    do {
#ifdef ATAFB_EXT
        if (external_addr) {
            printk("atafb_init: initializing external hw\n");
            fbhw = &ext_switch;
            atafb_ops.fb_setcolreg = &ext_setcolreg;
            defmode = DEFMODE_EXT;
            break;
        }
#endif
#ifdef ATAFB_TT
        if (ATARIHW_PRESENT(TT_SHIFTER)) {
            printk("atafb_init: initializing TT hw\n");
            fbhw = &tt_switch;
            atafb_ops.fb_setcolreg = &tt_setcolreg;
            defmode = DEFMODE_TT;
            break;
        }
#endif
#ifdef ATAFB_FALCON
        if (ATARIHW_PRESENT(VIDEL_SHIFTER)) {
            printk("atafb_init: initializing Falcon hw\n");
            fbhw = &falcon_switch;
            atafb_ops.fb_setcolreg = &falcon_setcolreg;
            error = request_irq(IRQ_AUTO_4, falcon_vbl_switcher,
                        IRQ_TYPE_PRIO,
                        "framebuffer:modeswitch",
                        falcon_vbl_switcher);
            if (error)
                return error;
            defmode = DEFMODE_F30;
            break;
        }
#endif
#ifdef ATAFB_STE
        if (ATARIHW_PRESENT(STND_SHIFTER) ||
            ATARIHW_PRESENT(EXTD_SHIFTER)) {
            printk("atafb_init: initializing ST/E hw\n");
            fbhw = &st_switch;
            atafb_ops.fb_setcolreg = &stste_setcolreg;
            defmode = DEFMODE_STE;
            break;
        }
        fbhw = &st_switch;
        atafb_ops.fb_setcolreg = &stste_setcolreg;
        printk("Cannot determine video hardware; defaulting to ST(e)\n");
#else /* ATAFB_STE */
        /* no default driver included */
        /* Nobody will ever see this message :-) */
        panic("Cannot initialize video hardware");
#endif
    } while (0);

    /* Multisync monitor capabilities */
    /* Atari-TOS defaults if no boot option present */
    if (fb_info.monspecs.hfmin == 0) {
        fb_info.monspecs.hfmin = 31000;
        fb_info.monspecs.hfmax = 32000;
        fb_info.monspecs.vfmin = 58;
        fb_info.monspecs.vfmax = 62;
    }

    detected_mode = fbhw->detect();
    check_default_par(detected_mode);
#ifdef ATAFB_EXT
    if (!external_addr) {
#endif /* ATAFB_EXT */
        mem_req = default_mem_req + ovsc_offset + ovsc_addlen;
        mem_req = PAGE_ALIGN(mem_req) + PAGE_SIZE;
        screen_base = atari_stram_alloc(mem_req, "atafb");
        if (!screen_base)
            panic("Cannot allocate screen memory");
        memset(screen_base, 0, mem_req);
        pad = -(unsigned long)screen_base & (PAGE_SIZE - 1);
        screen_base += pad;
        real_screen_base = screen_base + ovsc_offset;
        screen_len = (mem_req - pad - ovsc_offset) & PAGE_MASK;
        st_ovsc_switch();
        if (CPU_IS_040_OR_060) {
            /* On a '040+, the cache mode of video RAM must be set to
             * write-through also for internal video hardware! */
            cache_push(virt_to_phys(screen_base), screen_len);
            kernel_set_cachemode(screen_base, screen_len,
                         IOMAP_WRITETHROUGH);
        }
        printk("atafb: screen_base %p real_screen_base %p screen_len %d\n",
            screen_base, real_screen_base, screen_len);
#ifdef ATAFB_EXT
    } else {
        /* Map the video memory (physical address given) to somewhere
         * in the kernel address space.
         */
        external_addr = ioremap_writethrough((unsigned long)external_addr,
                             external_len);
        if (external_vgaiobase)
            external_vgaiobase =
              (unsigned long)ioremap(external_vgaiobase, 0x10000);
        screen_base =
        real_screen_base = external_addr;
        screen_len = external_len & PAGE_MASK;
        memset (screen_base, 0, external_len);
    }
#endif /* ATAFB_EXT */

//  strcpy(fb_info.mode->name, "Atari Builtin ");
    fb_info.fbops = &atafb_ops;
    // try to set default (detected; requested) var
    do_fb_set_var(&atafb_predefined[default_par - 1], 1);
    // reads hw state into current par, which may not be sane yet
    ata_get_par(&current_par);
    fb_info.par = &current_par;
    // tries to read from HW which may not be initialized yet
    // so set sane var first, then call atafb_set_par
    atafb_get_var(&fb_info.var, &fb_info);

#ifdef ATAFB_FALCON
    fb_info.pseudo_palette = current_par.hw.falcon.pseudo_palette;
#endif
    fb_info.flags = FBINFO_FLAG_DEFAULT;

    if (!fb_find_mode(&fb_info.var, &fb_info, mode_option, atafb_modedb,
              NUM_TOTAL_MODES, &atafb_modedb[defmode],
              fb_info.var.bits_per_pixel)) {
        return -EINVAL;
    }

    fb_videomode_to_modelist(atafb_modedb, NUM_TOTAL_MODES,
                 &fb_info.modelist);

    atafb_set_disp(&fb_info);

    fb_alloc_cmap(&(fb_info.cmap), 1 << fb_info.var.bits_per_pixel, 0);


    printk("Determined %dx%d, depth %d\n",
           fb_info.var.xres, fb_info.var.yres, fb_info.var.bits_per_pixel);
    if ((fb_info.var.xres != fb_info.var.xres_virtual) ||
        (fb_info.var.yres != fb_info.var.yres_virtual))
        printk("   virtual %dx%d\n", fb_info.var.xres_virtual,
               fb_info.var.yres_virtual);

    if (register_framebuffer(&fb_info) < 0) {
#ifdef ATAFB_EXT
        if (external_addr) {
            iounmap(external_addr);
            external_addr = NULL;
        }
        if (external_vgaiobase) {
            iounmap((void*)external_vgaiobase);
            external_vgaiobase = 0;
        }
#endif
        return -EINVAL;
    }

    // FIXME: mode needs setting!
    //printk("fb%d: %s frame buffer device, using %dK of video memory\n",
    //       fb_info.node, fb_info.mode->name, screen_len>>10);
    printk("fb%d: frame buffer device, using %dK of video memory\n",
           fb_info.node, screen_len >> 10);

    /* TODO: This driver cannot be unloaded yet */
    return 0;
}

module_init(atafb_init);

#ifdef MODULE
MODULE_LICENSE("GPL");

int cleanup_module(void)
{
    unregister_framebuffer(&fb_info);
    return atafb_deinit();
}
#endif /* MODULE */