Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3187 insertions, 0 deletions

diff --git a/drivers/video/fbdev/atafb.c b/drivers/video/fbdev/atafb.c
new file mode 100644
index 000000000..2bc408986
--- /dev/null
+++ b/drivers/video/fbdev/atafb.c
@@ -0,0 +1,3187 @@
+/*
+ * 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);