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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /*
  * 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 <guenther@pool.informatik.rwth-aachen.de>:
  *                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/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 <linux/platform_device.h>
 
 #include <asm/setup.h>
 #include <linux/uaccess.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
 
 
 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 unsigned long phys_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_screen_base;
 static unsigned long external_addr;
 static unsigned long external_len;
 static unsigned long external_vgaiobase;
 static unsigned int external_bitspercol = 6;
 
 /*
  * JOE <joe@amber.dinoco.de>:
  * 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 */
 
 
 /*
  * 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);
  *
  *  * 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
     }, {
         /* 640x200, 15 kHz, 60 Hz (ST medium) */
         "st-mid", 60, 640, 200, 32000, 32, 16, 31, 14, 96, 4,
         0, FB_VMODE_NONINTERLACED
     }, {
         /* 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
     }, {
         /* 320x480, 15 kHz, 60 Hz (TT low) */
         "tt-low", 60, 320, 480, 31041, 120, 100, 8, 16, 140, 30,
         0, FB_VMODE_NONINTERLACED
     }, {
         /* 640x480, 29 kHz, 57 Hz (TT medium) */
         "tt-mid", 60, 640, 480, 31041, 120, 100, 8, 16, 140, 30,
         0, FB_VMODE_NONINTERLACED
     }, {
         /* 1280x960, 72 kHz, 72 Hz (TT high) */
         "tt-high", 72, 1280, 960, 7760, 260, 60, 36, 4, 192, 4,
         0, FB_VMODE_NONINTERLACED
     },
 
     /*
      *  VGA Video Modes
      */
 
     {
         /* 640x480, 31 kHz, 60 Hz (VGA) */
         "vga", 60, 640, 480, 39721, 42, 18, 31, 11, 100, 3,
         0, FB_VMODE_NONINTERLACED
     }, {
         /* 640x400, 31 kHz, 70 Hz (VGA) */
         "vga70", 70, 640, 400, 39721, 42, 18, 31, 11, 100, 3,
         FB_SYNC_VERT_HIGH_ACT | FB_SYNC_COMP_HIGH_ACT, FB_VMODE_NONINTERLACED
     },
 
     /*
      *  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
     },
 };
 
 #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 = phys_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_st.syncmode;
     addr = ((shifter_st.bas_hi & 0xff) << 16) |
            ((shifter_st.bas_md & 0xff) << 8)  |
            ((shifter_st.bas_lo & 0xff));
     par->screen_base = atari_stram_to_virt(addr);
 }
 
 static void tt_set_par(struct atafb_par *par)
 {
     shifter_tt.tt_shiftmode = par->hw.tt.mode;
     shifter_st.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 = phys_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;
 
     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) {
             /* 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;
             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_st.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_st.bas_hi & 0xff) << 16 |
            (shifter_st.bas_md & 0xff) << 8  |
            (shifter_st.bas_lo & 0xff);
     par->screen_base = atari_stram_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_st.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 = info->par;
 
     int xoffset;
     int bpp = info->var.bits_per_pixel;
 
     if (bpp == 1)
         var->xoffset = round_up(var->xoffset, 32);
     if (bpp != 16)
         par->hw.falcon.xoffset = var->xoffset & 15;
     else {
         par->hw.falcon.xoffset = 0;
         var->xoffset = round_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 = phys_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_st.syncmode;
     addr = ((shifter_st.bas_hi & 0xff) << 16) |
            ((shifter_st.bas_md & 0xff) << 8);
     if (ATARIHW_PRESENT(EXTD_SHIFTER))
         addr |= (shifter_st.bas_lo & 0xff);
     par->screen_base = atari_stram_to_virt(addr);
 }
 
 static void stste_set_par(struct atafb_par *par)
 {
     shifter_tt.st_shiftmode = par->hw.st.mode;
     shifter_st.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 = atari_stram_to_phys(s_base);
     /* Setup Screen Memory */
     shifter_st.bas_hi = (unsigned char)((addr & 0xff0000) >> 16);
     shifter_st.bas_md = (unsigned char)((addr & 0x00ff00) >> 8);
     if (ATARIHW_PRESENT(EXTD_SHIFTER))
         shifter_st.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 = 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_screen_base;
 }
 
 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;
 
     red >>= 8;
     green >>= 8;
     blue >>= 8;
 
     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 = atari_stram_to_phys(s_base);
     /* Setup Screen Memory */
     shifter_st.bas_hi = (unsigned char)((addr & 0xff0000) >> 16);
     shifter_st.bas_md = (unsigned char)((addr & 0x00ff00) >> 8);
     shifter_st.bas_lo = (unsigned char)(addr & 0x0000ff);
 }
 
 static int pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
 {
     struct atafb_par *par = info->par;
 
     if (!fbhw->set_screen_base ||
         (!ATARIHW_PRESENT(EXTD_SHIFTER) && var->xoffset))
         return -EINVAL;
     var->xoffset = round_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);
 
     /* Note: smem_start derives from phys_screen_base, not screen_base! */
     info->screen_base = (external_addr ? external_screen_base :
                 atari_stram_to_virt(info->fix.smem_start));
 }
 
 static int
 atafb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
 {
     if (!fbhw->pan_display)
         return -EINVAL;
 
     return fbhw->pan_display(var, info);
 }
 
 /*
  * generic drawing routines; imageblit needs updating for image depth > 1
  */
 
 static void atafb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
 {
     struct atafb_par *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 = 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 = info->par;
     int x2, y2;
     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
         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, &current_par,
                  sizeof(struct atafb_par)))
             return -EFAULT;
         return 0;
 #endif
 #ifdef FBCMD_SET_CURRENTPAR
     case FBCMD_SET_CURRENTPAR:
         if (copy_from_user(&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 = 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_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 = 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;
     }
 }
 
 static 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"))
             fb_invert_cmaps();
         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;
 }
 
 static int __init atafb_probe(struct platform_device *pdev)
 {
     int pad, detected_mode, error;
     unsigned int defmode = 0;
     unsigned long mem_req;
     char *option = NULL;
 
     if (fb_get_options("atafb", &option))
         return -ENODEV;
     atafb_setup(option);
     dev_dbg(&pdev->dev, "%s: start\n", __func__);
 
     do {
 #ifdef ATAFB_EXT
         if (external_addr) {
             dev_dbg(&pdev->dev, "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)) {
             dev_dbg(&pdev->dev, "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)) {
             dev_dbg(&pdev->dev, "initializing Falcon hw\n");
             fbhw = &falcon_switch;
             atafb_ops.fb_setcolreg = &falcon_setcolreg;
             error = request_irq(IRQ_AUTO_4, falcon_vbl_switcher, 0,
                         "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)) {
             dev_dbg(&pdev->dev, "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;
         dev_warn(&pdev->dev,
              "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;
         phys_screen_base = atari_stram_to_phys(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(atari_stram_to_phys(screen_base), screen_len);
             kernel_set_cachemode(screen_base, screen_len,
                          IOMAP_WRITETHROUGH);
         }
         dev_info(&pdev->dev, "phys_screen_base %lx screen_len %d\n",
              phys_screen_base, screen_len);
 #ifdef ATAFB_EXT
     } else {
         /* Map the video memory (physical address given) to somewhere
          * in the kernel address space.
          */
         external_screen_base = ioremap_wt(external_addr, external_len);
         if (external_vgaiobase)
             external_vgaiobase =
               (unsigned long)ioremap(external_vgaiobase, 0x10000);
         screen_base = external_screen_base;
         phys_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);
 
 
     dev_info(&pdev->dev, "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))
         dev_info(&pdev->dev, "   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_screen_base);
             external_addr = 0;
         }
         if (external_vgaiobase) {
             iounmap((void*)external_vgaiobase);
             external_vgaiobase = 0;
         }
 #endif
         return -EINVAL;
     }
 
     fb_info(&fb_info, "frame buffer device, using %dK of video memory\n",
         screen_len >> 10);
 
     /* TODO: This driver cannot be unloaded yet */
     return 0;
 }
 
 static void atafb_shutdown(struct platform_device *pdev)
 {
     /* Unblank before kexec */
     if (fbhw->blank)
         fbhw->blank(0);
 }
 
 static struct platform_driver atafb_driver = {
     .shutdown   = atafb_shutdown,
     .driver = {
         .name   = "atafb",
     },
 };
 
 static int __init atafb_init(void)
 {
     struct platform_device *pdev;
 
     if (!MACH_IS_ATARI)
         return -ENODEV;
 
     pdev = platform_device_register_simple("atafb", -1, NULL, 0);
     if (IS_ERR(pdev))
         return PTR_ERR(pdev);
 
     return platform_driver_probe(&atafb_driver, atafb_probe);
 }
 
 device_initcall(atafb_init);