From bb3b2cfeb206f5b10b859e134651b54120e3f530 Mon Sep 17 00:00:00 2001
From: Linus Walleij <linusw@kernel.org>
Date: Tue, 30 Jun 2026 18:05:56 +0100
Subject: ARM: 9480/1: entry: expand comment in __switch_to

As per discussion between the developers in the mail thread
linked, expand the comment in __switch_to so that readers
of the code understand what is going on.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
 drivers/video/fbdev/vga16fb.c | 1442 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 1442 insertions(+)
 create mode 100644 drivers/video/fbdev/vga16fb.c

(limited to 'drivers/video/fbdev/vga16fb.c')

diff --git a/drivers/video/fbdev/vga16fb.c b/drivers/video/fbdev/vga16fb.c
new file mode 100644
index 000000000..22085d366
--- /dev/null
+++ b/drivers/video/fbdev/vga16fb.c
@@ -0,0 +1,1442 @@
+/*
+ * linux/drivers/video/vga16.c -- VGA 16-color framebuffer driver
+ *
+ * Copyright 1999 Ben Pfaff <pfaffben@debian.org> and Petr Vandrovec <VANDROVE@vc.cvut.cz>
+ * Based on VGA info at http://www.goodnet.com/~tinara/FreeVGA/home.htm
+ * Based on VESA framebuffer (c) 1998 Gerd Knorr <kraxel@goldbach.in-berlin.de>
+ *
+ * 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.
+ */
+
+#include <linux/aperture.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/fb.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/sysfb.h>
+
+#include <asm/io.h>
+#include <video/vga.h>
+
+#define MODE_SKIP4	1
+#define MODE_8BPP	2
+#define MODE_CFB	4
+#define MODE_TEXT	8
+
+/* --------------------------------------------------------------------- */
+
+/*
+ * card parameters
+ */
+
+struct vga16fb_par {
+	/* structure holding original VGA register settings when the
+           screen is blanked */
+	struct {
+		unsigned char	SeqCtrlIndex;	  /* Sequencer Index reg.   */
+		unsigned char	CrtCtrlIndex;	  /* CRT-Contr. Index reg.  */
+		unsigned char	CrtMiscIO;	  /* Miscellaneous register */
+		unsigned char	HorizontalTotal;  /* CRT-Controller:00h */
+		unsigned char	HorizDisplayEnd;  /* CRT-Controller:01h */
+		unsigned char	StartHorizRetrace;/* CRT-Controller:04h */
+		unsigned char	EndHorizRetrace;  /* CRT-Controller:05h */
+		unsigned char	Overflow;	  /* CRT-Controller:07h */
+		unsigned char	StartVertRetrace; /* CRT-Controller:10h */
+		unsigned char	EndVertRetrace;	  /* CRT-Controller:11h */
+		unsigned char	ModeControl;	  /* CRT-Controller:17h */
+		unsigned char	ClockingMode;	  /* Seq-Controller:01h */
+	} vga_state;
+	struct vgastate state;
+	unsigned int ref_count;
+	int palette_blanked, vesa_blanked, mode, isVGA;
+	u8 misc, pel_msk, vss, clkdiv;
+	u8 crtc[VGA_CRT_C];
+};
+
+/* --------------------------------------------------------------------- */
+
+static struct fb_var_screeninfo vga16fb_defined = {
+	.xres		= 640,
+	.yres		= 480,
+	.xres_virtual	= 640,
+	.yres_virtual	= 480,
+	.bits_per_pixel	= 4,
+	.activate	= FB_ACTIVATE_TEST,
+	.height		= -1,
+	.width		= -1,
+	.pixclock	= 39721,
+	.left_margin	= 48,
+	.right_margin	= 16,
+	.upper_margin	= 33,
+	.lower_margin	= 10,
+	.hsync_len 	= 96,
+	.vsync_len	= 2,
+	.vmode		= FB_VMODE_NONINTERLACED,
+};
+
+/* name should not depend on EGA/VGA */
+static const struct fb_fix_screeninfo vga16fb_fix = {
+	.id		= "VGA16 VGA",
+	.smem_start	= VGA_FB_PHYS_BASE,
+	.smem_len	= VGA_FB_PHYS_SIZE,
+	.type		= FB_TYPE_VGA_PLANES,
+	.type_aux	= FB_AUX_VGA_PLANES_VGA4,
+	.visual		= FB_VISUAL_PSEUDOCOLOR,
+	.xpanstep	= 8,
+	.ypanstep	= 1,
+	.line_length	= 640 / 8,
+	.accel		= FB_ACCEL_NONE
+};
+
+/* The VGA's weird architecture often requires that we read a byte and
+   write a byte to the same location.  It doesn't matter *what* byte
+   we write, however.  This is because all the action goes on behind
+   the scenes in the VGA's 32-bit latch register, and reading and writing
+   video memory just invokes latch behavior.
+
+   To avoid race conditions (is this necessary?), reading and writing
+   the memory byte should be done with a single instruction.  One
+   suitable instruction is the x86 bitwise OR.  The following
+   read-modify-write routine should optimize to one such bitwise
+   OR. */
+static inline void rmw(volatile char __iomem *p)
+{
+	readb(p);
+	writeb(1, p);
+}
+
+/* Set the Graphics Mode Register, and return its previous value.
+   Bits 0-1 are write mode, bit 3 is read mode. */
+static inline int setmode(int mode)
+{
+	int oldmode;
+
+	oldmode = vga_io_rgfx(VGA_GFX_MODE);
+	vga_io_w(VGA_GFX_D, mode);
+	return oldmode;
+}
+
+/* Select the Bit Mask Register and return its value. */
+static inline int selectmask(void)
+{
+	return vga_io_rgfx(VGA_GFX_BIT_MASK);
+}
+
+/* Set the value of the Bit Mask Register.  It must already have been
+   selected with selectmask(). */
+static inline void setmask(int mask)
+{
+	vga_io_w(VGA_GFX_D, mask);
+}
+
+/* Set the Data Rotate Register and return its old value.
+   Bits 0-2 are rotate count, bits 3-4 are logical operation
+   (0=NOP, 1=AND, 2=OR, 3=XOR). */
+static inline int setop(int op)
+{
+	int oldop;
+
+	oldop = vga_io_rgfx(VGA_GFX_DATA_ROTATE);
+	vga_io_w(VGA_GFX_D, op);
+	return oldop;
+}
+
+/* Set the Enable Set/Reset Register and return its old value.
+   The code here always uses value 0xf for this register. */
+static inline int setsr(int sr)
+{
+	int oldsr;
+
+	oldsr = vga_io_rgfx(VGA_GFX_SR_ENABLE);
+	vga_io_w(VGA_GFX_D, sr);
+	return oldsr;
+}
+
+/* Set the Set/Reset Register and return its old value. */
+static inline int setcolor(int color)
+{
+	int oldcolor;
+
+	oldcolor = vga_io_rgfx(VGA_GFX_SR_VALUE);
+	vga_io_w(VGA_GFX_D, color);
+	return oldcolor;
+}
+
+/* Return the value in the Graphics Address Register. */
+static inline int getindex(void)
+{
+	return vga_io_r(VGA_GFX_I);
+}
+
+/* Set the value in the Graphics Address Register. */
+static inline void setindex(int index)
+{
+	vga_io_w(VGA_GFX_I, index);
+}
+
+/* Check if the video mode is supported by the driver */
+static inline int check_mode_supported(const struct screen_info *si)
+{
+	unsigned int type = screen_info_video_type(si);
+
+	/* only EGA and VGA in 16 color graphic mode are supported */
+	if (type != VIDEO_TYPE_EGAC && type != VIDEO_TYPE_VGAC)
+		return -ENODEV;
+
+	if (si->orig_video_mode != 0x0D &&	/* 320x200/4 (EGA) */
+	    si->orig_video_mode != 0x0E &&	/* 640x200/4 (EGA) */
+	    si->orig_video_mode != 0x10 &&	/* 640x350/4 (EGA) */
+	    si->orig_video_mode != 0x12)	/* 640x480/4 (VGA) */
+		return -ENODEV;
+
+	return 0;
+}
+
+static void vga16fb_pan_var(struct fb_info *info,
+			    struct fb_var_screeninfo *var)
+{
+	struct vga16fb_par *par = info->par;
+	u32 xoffset, pos;
+
+	xoffset = var->xoffset;
+	if (info->var.bits_per_pixel == 8) {
+		pos = (info->var.xres_virtual * var->yoffset + xoffset) >> 2;
+	} else if (par->mode & MODE_TEXT) {
+		int fh = 16; // FIXME !!! font height. Fugde for now.
+		pos = (info->var.xres_virtual * (var->yoffset / fh) + xoffset) >> 3;
+	} else {
+		if (info->var.nonstd)
+			xoffset--;
+		pos = (info->var.xres_virtual * var->yoffset + xoffset) >> 3;
+	}
+	vga_io_wcrt(VGA_CRTC_START_HI, pos >> 8);
+	vga_io_wcrt(VGA_CRTC_START_LO, pos & 0xFF);
+	/* if we support CFB4, then we must! support xoffset with pixel
+	 * granularity if someone supports xoffset in bit resolution */
+	vga_io_r(VGA_IS1_RC);		/* reset flip-flop */
+	vga_io_w(VGA_ATT_IW, VGA_ATC_PEL);
+	if (info->var.bits_per_pixel == 8)
+		vga_io_w(VGA_ATT_IW, (xoffset & 3) << 1);
+	else
+		vga_io_w(VGA_ATT_IW, xoffset & 7);
+	vga_io_r(VGA_IS1_RC);
+	vga_io_w(VGA_ATT_IW, 0x20);
+}
+
+static void vga16fb_update_fix(struct fb_info *info)
+{
+	if (info->var.bits_per_pixel == 4) {
+		if (info->var.nonstd) {
+			info->fix.type = FB_TYPE_PACKED_PIXELS;
+			info->fix.line_length = info->var.xres_virtual / 2;
+		} else {
+			info->fix.type = FB_TYPE_VGA_PLANES;
+			info->fix.type_aux = FB_AUX_VGA_PLANES_VGA4;
+			info->fix.line_length = info->var.xres_virtual / 8;
+		}
+	} else if (info->var.bits_per_pixel == 0) {
+		info->fix.type = FB_TYPE_TEXT;
+		info->fix.type_aux = FB_AUX_TEXT_CGA;
+		info->fix.line_length = info->var.xres_virtual / 4;
+	} else {	/* 8bpp */
+		if (info->var.nonstd) {
+			info->fix.type = FB_TYPE_VGA_PLANES;
+			info->fix.type_aux = FB_AUX_VGA_PLANES_CFB8;
+			info->fix.line_length = info->var.xres_virtual / 4;
+		} else {
+			info->fix.type = FB_TYPE_PACKED_PIXELS;
+			info->fix.line_length = info->var.xres_virtual;
+		}
+	}
+}
+
+static void vga16fb_clock_chip(struct vga16fb_par *par,
+			       unsigned int *pixclock,
+			       const struct fb_info *info,
+			       int mul, int div)
+{
+	static const struct {
+		u32 pixclock;
+		u8  misc;
+		u8  seq_clock_mode;
+	} *ptr, *best, vgaclocks[] = {
+		{ 79442 /* 12.587 */, 0x00, 0x08},
+		{ 70616 /* 14.161 */, 0x04, 0x08},
+		{ 39721 /* 25.175 */, 0x00, 0x00},
+		{ 35308 /* 28.322 */, 0x04, 0x00},
+		{     0 /* bad */,    0x00, 0x00}};
+	int err;
+
+	*pixclock = (*pixclock * mul) / div;
+	best = vgaclocks;
+	err = *pixclock - best->pixclock;
+	if (err < 0) err = -err;
+	for (ptr = vgaclocks + 1; ptr->pixclock; ptr++) {
+		int tmp;
+
+		tmp = *pixclock - ptr->pixclock;
+		if (tmp < 0) tmp = -tmp;
+		if (tmp < err) {
+			err = tmp;
+			best = ptr;
+		}
+	}
+	par->misc |= best->misc;
+	par->clkdiv = best->seq_clock_mode;
+	*pixclock = (best->pixclock * div) / mul;
+}
+
+#define FAIL(X) return -EINVAL
+
+static int vga16fb_open(struct fb_info *info, int user)
+{
+	struct vga16fb_par *par = info->par;
+
+	if (!par->ref_count) {
+		memset(&par->state, 0, sizeof(struct vgastate));
+		par->state.flags = VGA_SAVE_FONTS | VGA_SAVE_MODE |
+			VGA_SAVE_CMAP;
+		save_vga(&par->state);
+	}
+	par->ref_count++;
+
+	return 0;
+}
+
+static int vga16fb_release(struct fb_info *info, int user)
+{
+	struct vga16fb_par *par = info->par;
+
+	if (!par->ref_count)
+		return -EINVAL;
+
+	if (par->ref_count == 1)
+		restore_vga(&par->state);
+	par->ref_count--;
+
+	return 0;
+}
+
+static int vga16fb_check_var(struct fb_var_screeninfo *var,
+			     struct fb_info *info)
+{
+	struct vga16fb_par *par = info->par;
+	u32 xres, right, hslen, left, xtotal;
+	u32 yres, lower, vslen, upper, ytotal;
+	u32 vxres, xoffset, vyres, yoffset;
+	u32 pos;
+	u8 r7, rMode;
+	int shift;
+	int mode;
+	u32 maxmem;
+
+	par->pel_msk = 0xFF;
+
+	if (var->bits_per_pixel == 4) {
+		if (var->nonstd) {
+			if (!par->isVGA)
+				return -EINVAL;
+			shift = 3;
+			mode = MODE_SKIP4 | MODE_CFB;
+			maxmem = 16384;
+			par->pel_msk = 0x0F;
+		} else {
+			shift = 3;
+			mode = 0;
+			maxmem = 65536;
+		}
+	} else if (var->bits_per_pixel == 8) {
+		if (!par->isVGA)
+			return -EINVAL;	/* no support on EGA */
+		shift = 2;
+		if (var->nonstd) {
+			mode = MODE_8BPP | MODE_CFB;
+			maxmem = 65536;
+		} else {
+			mode = MODE_SKIP4 | MODE_8BPP | MODE_CFB;
+			maxmem = 16384;
+		}
+	} else
+		return -EINVAL;
+
+	xres = (var->xres + 7) & ~7;
+	vxres = (var->xres_virtual + 0xF) & ~0xF;
+	xoffset = (var->xoffset + 7) & ~7;
+	left = (var->left_margin + 7) & ~7;
+	right = (var->right_margin + 7) & ~7;
+	hslen = (var->hsync_len + 7) & ~7;
+
+	if (vxres < xres)
+		vxres = xres;
+	if (xres + xoffset > vxres)
+		xoffset = vxres - xres;
+
+	var->xres = xres;
+	var->right_margin = right;
+	var->hsync_len = hslen;
+	var->left_margin = left;
+	var->xres_virtual = vxres;
+	var->xoffset = xoffset;
+
+	xres >>= shift;
+	right >>= shift;
+	hslen >>= shift;
+	left >>= shift;
+	vxres >>= shift;
+	xtotal = xres + right + hslen + left;
+	if (xtotal >= 256)
+		FAIL("xtotal too big");
+	if (hslen > 32)
+		FAIL("hslen too big");
+	if (right + hslen + left > 64)
+		FAIL("hblank too big");
+	par->crtc[VGA_CRTC_H_TOTAL] = xtotal - 5;
+	par->crtc[VGA_CRTC_H_BLANK_START] = xres - 1;
+	par->crtc[VGA_CRTC_H_DISP] = xres - 1;
+	pos = xres + right;
+	par->crtc[VGA_CRTC_H_SYNC_START] = pos;
+	pos += hslen;
+	par->crtc[VGA_CRTC_H_SYNC_END] = pos & 0x1F;
+	pos += left - 2; /* blank_end + 2 <= total + 5 */
+	par->crtc[VGA_CRTC_H_BLANK_END] = (pos & 0x1F) | 0x80;
+	if (pos & 0x20)
+		par->crtc[VGA_CRTC_H_SYNC_END] |= 0x80;
+
+	yres = var->yres;
+	lower = var->lower_margin;
+	vslen = var->vsync_len;
+	upper = var->upper_margin;
+	vyres = var->yres_virtual;
+	yoffset = var->yoffset;
+
+	if (yres > vyres)
+		vyres = yres;
+	if (vxres * vyres > maxmem) {
+		vyres = maxmem / vxres;
+		if (vyres < yres)
+			return -ENOMEM;
+	}
+	if (yoffset + yres > vyres)
+		yoffset = vyres - yres;
+	var->yres = yres;
+	var->lower_margin = lower;
+	var->vsync_len = vslen;
+	var->upper_margin = upper;
+	var->yres_virtual = vyres;
+	var->yoffset = yoffset;
+
+	if (var->vmode & FB_VMODE_DOUBLE) {
+		yres <<= 1;
+		lower <<= 1;
+		vslen <<= 1;
+		upper <<= 1;
+	}
+	ytotal = yres + lower + vslen + upper;
+	if (ytotal > 1024) {
+		ytotal >>= 1;
+		yres >>= 1;
+		lower >>= 1;
+		vslen >>= 1;
+		upper >>= 1;
+		rMode = 0x04;
+	} else
+		rMode = 0x00;
+	if (ytotal > 1024)
+		FAIL("ytotal too big");
+	if (vslen > 16)
+		FAIL("vslen too big");
+	par->crtc[VGA_CRTC_V_TOTAL] = ytotal - 2;
+	r7 = 0x10;	/* disable linecompare */
+	if (ytotal & 0x100) r7 |= 0x01;
+	if (ytotal & 0x200) r7 |= 0x20;
+	par->crtc[VGA_CRTC_PRESET_ROW] = 0;
+	par->crtc[VGA_CRTC_MAX_SCAN] = 0x40;	/* 1 scanline, no linecmp */
+	if (var->vmode & FB_VMODE_DOUBLE)
+		par->crtc[VGA_CRTC_MAX_SCAN] |= 0x80;
+	par->crtc[VGA_CRTC_CURSOR_START] = 0x20;
+	par->crtc[VGA_CRTC_CURSOR_END]   = 0x00;
+	if ((mode & (MODE_CFB | MODE_8BPP)) == MODE_CFB)
+		xoffset--;
+	pos = yoffset * vxres + (xoffset >> shift);
+	par->crtc[VGA_CRTC_START_HI]     = pos >> 8;
+	par->crtc[VGA_CRTC_START_LO]     = pos & 0xFF;
+	par->crtc[VGA_CRTC_CURSOR_HI]    = 0x00;
+	par->crtc[VGA_CRTC_CURSOR_LO]    = 0x00;
+	pos = yres - 1;
+	par->crtc[VGA_CRTC_V_DISP_END] = pos & 0xFF;
+	par->crtc[VGA_CRTC_V_BLANK_START] = pos & 0xFF;
+	if (pos & 0x100)
+		r7 |= 0x0A;	/* 0x02 -> DISP_END, 0x08 -> BLANK_START */
+	if (pos & 0x200) {
+		r7 |= 0x40;	/* 0x40 -> DISP_END */
+		par->crtc[VGA_CRTC_MAX_SCAN] |= 0x20; /* BLANK_START */
+	}
+	pos += lower;
+	par->crtc[VGA_CRTC_V_SYNC_START] = pos & 0xFF;
+	if (pos & 0x100)
+		r7 |= 0x04;
+	if (pos & 0x200)
+		r7 |= 0x80;
+	pos += vslen;
+	par->crtc[VGA_CRTC_V_SYNC_END] = (pos & 0x0F) & ~0x10; /* disabled IRQ */
+	pos += upper - 1; /* blank_end + 1 <= ytotal + 2 */
+	par->crtc[VGA_CRTC_V_BLANK_END] = pos & 0xFF; /* 0x7F for original VGA,
+                     but some SVGA chips requires all 8 bits to set */
+	if (vxres >= 512)
+		FAIL("vxres too long");
+	par->crtc[VGA_CRTC_OFFSET] = vxres >> 1;
+	if (mode & MODE_SKIP4)
+		par->crtc[VGA_CRTC_UNDERLINE] = 0x5F;	/* 256, cfb8 */
+	else
+		par->crtc[VGA_CRTC_UNDERLINE] = 0x1F;	/* 16, vgap */
+	par->crtc[VGA_CRTC_MODE] = rMode | ((mode & MODE_TEXT) ? 0xA3 : 0xE3);
+	par->crtc[VGA_CRTC_LINE_COMPARE] = 0xFF;
+	par->crtc[VGA_CRTC_OVERFLOW] = r7;
+
+	par->vss = 0x00;	/* 3DA */
+
+	par->misc = 0xE3;	/* enable CPU, ports 0x3Dx, positive sync */
+	if (var->sync & FB_SYNC_HOR_HIGH_ACT)
+		par->misc &= ~0x40;
+	if (var->sync & FB_SYNC_VERT_HIGH_ACT)
+		par->misc &= ~0x80;
+
+	par->mode = mode;
+
+	if (mode & MODE_8BPP)
+		/* pixel clock == vga clock / 2 */
+		vga16fb_clock_chip(par, &var->pixclock, info, 1, 2);
+	else
+		/* pixel clock == vga clock */
+		vga16fb_clock_chip(par, &var->pixclock, info, 1, 1);
+
+	var->red.offset = var->green.offset = var->blue.offset =
+	var->transp.offset = 0;
+	var->red.length = var->green.length = var->blue.length =
+		(par->isVGA) ? 6 : 2;
+	var->transp.length = 0;
+	var->activate = FB_ACTIVATE_NOW;
+	var->height = -1;
+	var->width = -1;
+	var->accel_flags = 0;
+	return 0;
+}
+#undef FAIL
+
+static int vga16fb_set_par(struct fb_info *info)
+{
+	struct vga16fb_par *par = info->par;
+	u8 gdc[VGA_GFX_C];
+	u8 seq[VGA_SEQ_C];
+	u8 atc[VGA_ATT_C];
+	int fh, i;
+
+	seq[VGA_SEQ_CLOCK_MODE] = 0x01 | par->clkdiv;
+	if (par->mode & MODE_TEXT)
+		seq[VGA_SEQ_PLANE_WRITE] = 0x03;
+	else
+		seq[VGA_SEQ_PLANE_WRITE] = 0x0F;
+	seq[VGA_SEQ_CHARACTER_MAP] = 0x00;
+	if (par->mode & MODE_TEXT)
+		seq[VGA_SEQ_MEMORY_MODE] = 0x03;
+	else if (par->mode & MODE_SKIP4)
+		seq[VGA_SEQ_MEMORY_MODE] = 0x0E;
+	else
+		seq[VGA_SEQ_MEMORY_MODE] = 0x06;
+
+	gdc[VGA_GFX_SR_VALUE] = 0x00;
+	gdc[VGA_GFX_SR_ENABLE] = 0x00;
+	gdc[VGA_GFX_COMPARE_VALUE] = 0x00;
+	gdc[VGA_GFX_DATA_ROTATE] = 0x00;
+	gdc[VGA_GFX_PLANE_READ] = 0;
+	if (par->mode & MODE_TEXT) {
+		gdc[VGA_GFX_MODE] = 0x10;
+		gdc[VGA_GFX_MISC] = 0x06;
+	} else {
+		if (par->mode & MODE_CFB)
+			gdc[VGA_GFX_MODE] = 0x40;
+		else
+			gdc[VGA_GFX_MODE] = 0x00;
+		gdc[VGA_GFX_MISC] = 0x05;
+	}
+	gdc[VGA_GFX_COMPARE_MASK] = 0x0F;
+	gdc[VGA_GFX_BIT_MASK] = 0xFF;
+
+	for (i = 0x00; i < 0x10; i++)
+		atc[i] = i;
+	if (par->mode & MODE_TEXT)
+		atc[VGA_ATC_MODE] = 0x04;
+	else if (par->mode & MODE_8BPP)
+		atc[VGA_ATC_MODE] = 0x41;
+	else
+		atc[VGA_ATC_MODE] = 0x81;
+	atc[VGA_ATC_OVERSCAN] = 0x00;	/* 0 for EGA, 0xFF for VGA */
+	atc[VGA_ATC_PLANE_ENABLE] = 0x0F;
+	if (par->mode & MODE_8BPP)
+		atc[VGA_ATC_PEL] = (info->var.xoffset & 3) << 1;
+	else
+		atc[VGA_ATC_PEL] = info->var.xoffset & 7;
+	atc[VGA_ATC_COLOR_PAGE] = 0x00;
+
+	if (par->mode & MODE_TEXT) {
+		fh = 16; // FIXME !!! Fudge font height.
+		par->crtc[VGA_CRTC_MAX_SCAN] = (par->crtc[VGA_CRTC_MAX_SCAN]
+					       & ~0x1F) | (fh - 1);
+	}
+
+	vga_io_w(VGA_MIS_W, vga_io_r(VGA_MIS_R) | 0x01);
+
+	/* Enable graphics register modification */
+	if (!par->isVGA) {
+		vga_io_w(EGA_GFX_E0, 0x00);
+		vga_io_w(EGA_GFX_E1, 0x01);
+	}
+
+	/* update misc output register */
+	vga_io_w(VGA_MIS_W, par->misc);
+
+	/* synchronous reset on */
+	vga_io_wseq(0x00, 0x01);
+
+	if (par->isVGA)
+		vga_io_w(VGA_PEL_MSK, par->pel_msk);
+
+	/* write sequencer registers */
+	vga_io_wseq(VGA_SEQ_CLOCK_MODE, seq[VGA_SEQ_CLOCK_MODE] | 0x20);
+	for (i = 2; i < VGA_SEQ_C; i++) {
+		vga_io_wseq(i, seq[i]);
+	}
+
+	/* synchronous reset off */
+	vga_io_wseq(0x00, 0x03);
+
+	/* deprotect CRT registers 0-7 */
+	vga_io_wcrt(VGA_CRTC_V_SYNC_END, par->crtc[VGA_CRTC_V_SYNC_END]);
+
+	/* write CRT registers */
+	for (i = 0; i < VGA_CRTC_REGS; i++) {
+		vga_io_wcrt(i, par->crtc[i]);
+	}
+
+	/* write graphics controller registers */
+	for (i = 0; i < VGA_GFX_C; i++) {
+		vga_io_wgfx(i, gdc[i]);
+	}
+
+	/* write attribute controller registers */
+	for (i = 0; i < VGA_ATT_C; i++) {
+		vga_io_r(VGA_IS1_RC);		/* reset flip-flop */
+		vga_io_wattr(i, atc[i]);
+	}
+
+	/* Wait for screen to stabilize. */
+	mdelay(50);
+
+	vga_io_wseq(VGA_SEQ_CLOCK_MODE, seq[VGA_SEQ_CLOCK_MODE]);
+
+	vga_io_r(VGA_IS1_RC);
+	vga_io_w(VGA_ATT_IW, 0x20);
+
+	vga16fb_update_fix(info);
+	return 0;
+}
+
+static void ega16_setpalette(int regno, unsigned red, unsigned green, unsigned blue)
+{
+	static const unsigned char map[] = { 000, 001, 010, 011 };
+	int val;
+
+	if (regno >= 16)
+		return;
+	val = map[red>>14] | ((map[green>>14]) << 1) | ((map[blue>>14]) << 2);
+	vga_io_r(VGA_IS1_RC);   /* ! 0x3BA */
+	vga_io_wattr(regno, val);
+	vga_io_r(VGA_IS1_RC);   /* some clones need it */
+	vga_io_w(VGA_ATT_IW, 0x20); /* unblank screen */
+}
+
+static void vga16_setpalette(int regno, unsigned red, unsigned green, unsigned blue)
+{
+	outb(regno,       VGA_PEL_IW);
+	outb(red   >> 10, VGA_PEL_D);
+	outb(green >> 10, VGA_PEL_D);
+	outb(blue  >> 10, VGA_PEL_D);
+}
+
+static int vga16fb_setcolreg(unsigned regno, unsigned red, unsigned green,
+			     unsigned blue, unsigned transp,
+			     struct fb_info *info)
+{
+	struct vga16fb_par *par = info->par;
+	int gray;
+
+	/*
+	 *  Set a single color register. The values supplied are
+	 *  already rounded down to the hardware's capabilities
+	 *  (according to the entries in the `var' structure). Return
+	 *  != 0 for invalid regno.
+	 */
+
+	if (regno >= 256)
+		return 1;
+
+	gray = info->var.grayscale;
+
+	if (gray) {
+		/* gray = 0.30*R + 0.59*G + 0.11*B */
+		red = green = blue = (red * 77 + green * 151 + blue * 28) >> 8;
+	}
+	if (par->isVGA)
+		vga16_setpalette(regno,red,green,blue);
+	else
+		ega16_setpalette(regno,red,green,blue);
+	return 0;
+}
+
+static int vga16fb_pan_display(struct fb_var_screeninfo *var,
+			       struct fb_info *info)
+{
+	vga16fb_pan_var(info, var);
+	return 0;
+}
+
+/* The following VESA blanking code is taken from vgacon.c.  The VGA
+   blanking code was originally by Huang shi chao, and modified by
+   Christoph Rimek (chrimek@toppoint.de) and todd j. derr
+   (tjd@barefoot.org) for Linux. */
+
+static void vga_vesa_blank(struct vga16fb_par *par, int mode)
+{
+	unsigned char SeqCtrlIndex = vga_io_r(VGA_SEQ_I);
+	unsigned char CrtCtrlIndex = vga_io_r(VGA_CRT_IC);
+
+	/* save original values of VGA controller registers */
+	if(!par->vesa_blanked) {
+		par->vga_state.CrtMiscIO = vga_io_r(VGA_MIS_R);
+		//sti();
+
+		par->vga_state.HorizontalTotal = vga_io_rcrt(0x00);	/* HorizontalTotal */
+		par->vga_state.HorizDisplayEnd = vga_io_rcrt(0x01);	/* HorizDisplayEnd */
+		par->vga_state.StartHorizRetrace = vga_io_rcrt(0x04);	/* StartHorizRetrace */
+		par->vga_state.EndHorizRetrace = vga_io_rcrt(0x05);	/* EndHorizRetrace */
+		par->vga_state.Overflow = vga_io_rcrt(0x07);		/* Overflow */
+		par->vga_state.StartVertRetrace = vga_io_rcrt(0x10);	/* StartVertRetrace */
+		par->vga_state.EndVertRetrace = vga_io_rcrt(0x11);	/* EndVertRetrace */
+		par->vga_state.ModeControl = vga_io_rcrt(0x17);	/* ModeControl */
+		par->vga_state.ClockingMode = vga_io_rseq(0x01);	/* ClockingMode */
+	}
+
+	/* assure that video is enabled */
+	/* "0x20" is VIDEO_ENABLE_bit in register 01 of sequencer */
+	vga_io_wseq(0x01, par->vga_state.ClockingMode | 0x20);
+
+	/* test for vertical retrace in process.... */
+	if ((par->vga_state.CrtMiscIO & 0x80) == 0x80)
+		vga_io_w(VGA_MIS_W, par->vga_state.CrtMiscIO & 0xef);
+
+	/*
+	 * Set <End of vertical retrace> to minimum (0) and
+	 * <Start of vertical Retrace> to maximum (incl. overflow)
+	 * Result: turn off vertical sync (VSync) pulse.
+	 */
+	if (mode & FB_BLANK_VSYNC_SUSPEND) {
+		vga_io_wcrt(VGA_CRTC_V_SYNC_START, 0xff);
+		vga_io_wcrt(VGA_CRTC_V_SYNC_END, 0x40);
+		/* bits 9,10 of vert. retrace */
+		vga_io_wcrt(VGA_CRTC_OVERFLOW, par->vga_state.Overflow | 0x84);
+	}
+
+	if (mode & FB_BLANK_HSYNC_SUSPEND) {
+		/*
+		 * Set <End of horizontal retrace> to minimum (0) and
+		 *  <Start of horizontal Retrace> to maximum
+		 * Result: turn off horizontal sync (HSync) pulse.
+		 */
+		vga_io_wcrt(VGA_CRTC_H_SYNC_START, 0xff);
+		vga_io_wcrt(VGA_CRTC_H_SYNC_END, 0x00);
+	}
+
+	/* restore both index registers */
+	outb_p(SeqCtrlIndex, VGA_SEQ_I);
+	outb_p(CrtCtrlIndex, VGA_CRT_IC);
+}
+
+static void vga_vesa_unblank(struct vga16fb_par *par)
+{
+	unsigned char SeqCtrlIndex = vga_io_r(VGA_SEQ_I);
+	unsigned char CrtCtrlIndex = vga_io_r(VGA_CRT_IC);
+
+	/* restore original values of VGA controller registers */
+	vga_io_w(VGA_MIS_W, par->vga_state.CrtMiscIO);
+
+	/* HorizontalTotal */
+	vga_io_wcrt(0x00, par->vga_state.HorizontalTotal);
+	/* HorizDisplayEnd */
+	vga_io_wcrt(0x01, par->vga_state.HorizDisplayEnd);
+	/* StartHorizRetrace */
+	vga_io_wcrt(0x04, par->vga_state.StartHorizRetrace);
+	/* EndHorizRetrace */
+	vga_io_wcrt(0x05, par->vga_state.EndHorizRetrace);
+	/* Overflow */
+	vga_io_wcrt(0x07, par->vga_state.Overflow);
+	/* StartVertRetrace */
+	vga_io_wcrt(0x10, par->vga_state.StartVertRetrace);
+	/* EndVertRetrace */
+	vga_io_wcrt(0x11, par->vga_state.EndVertRetrace);
+	/* ModeControl */
+	vga_io_wcrt(0x17, par->vga_state.ModeControl);
+	/* ClockingMode */
+	vga_io_wseq(0x01, par->vga_state.ClockingMode);
+
+	/* restore index/control registers */
+	vga_io_w(VGA_SEQ_I, SeqCtrlIndex);
+	vga_io_w(VGA_CRT_IC, CrtCtrlIndex);
+}
+
+static void vga_pal_blank(void)
+{
+	int i;
+
+	for (i=0; i<16; i++) {
+		outb_p(i, VGA_PEL_IW);
+		outb_p(0, VGA_PEL_D);
+		outb_p(0, VGA_PEL_D);
+		outb_p(0, VGA_PEL_D);
+	}
+}
+
+/* 0 unblank, 1 blank, 2 no vsync, 3 no hsync, 4 off */
+static int vga16fb_blank(int blank, struct fb_info *info)
+{
+	struct vga16fb_par *par = info->par;
+
+	switch (blank) {
+	case FB_BLANK_UNBLANK:				/* Unblank */
+		if (par->vesa_blanked) {
+			vga_vesa_unblank(par);
+			par->vesa_blanked = 0;
+		}
+		if (par->palette_blanked) {
+			par->palette_blanked = 0;
+		}
+		break;
+	case FB_BLANK_NORMAL:				/* blank */
+		vga_pal_blank();
+		par->palette_blanked = 1;
+		break;
+	default:			/* VESA blanking */
+		vga_vesa_blank(par, blank);
+		par->vesa_blanked = 1;
+		break;
+	}
+	return 0;
+}
+
+static void vga_8planes_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
+{
+	u32 dx = rect->dx, width = rect->width;
+        char oldindex = getindex();
+        char oldmode = setmode(0x40);
+        char oldmask = selectmask();
+        int line_ofs, height;
+        char oldop, oldsr;
+        char __iomem *where;
+
+        dx /= 4;
+        where = info->screen_base + dx + rect->dy * info->fix.line_length;
+
+        if (rect->rop == ROP_COPY) {
+                oldop = setop(0);
+                oldsr = setsr(0);
+
+                width /= 4;
+                line_ofs = info->fix.line_length - width;
+                setmask(0xff);
+
+                height = rect->height;
+
+                while (height--) {
+                        int x;
+
+                        /* we can do memset... */
+                        for (x = width; x > 0; --x) {
+                                writeb(rect->color, where);
+                                where++;
+                        }
+                        where += line_ofs;
+                }
+        } else {
+                char oldcolor = setcolor(0xf);
+                int y;
+
+                oldop = setop(0x18);
+                oldsr = setsr(0xf);
+                setmask(0x0F);
+                for (y = 0; y < rect->height; y++) {
+                        rmw(where);
+                        rmw(where+1);
+                        where += info->fix.line_length;
+                }
+                setcolor(oldcolor);
+        }
+        setmask(oldmask);
+        setsr(oldsr);
+        setop(oldop);
+        setmode(oldmode);
+        setindex(oldindex);
+}
+
+static void vga16fb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
+{
+	int x, x2, y2, vxres, vyres, width, height, line_ofs;
+	char __iomem *dst;
+
+	vxres = info->var.xres_virtual;
+	vyres = info->var.yres_virtual;
+
+	if (!rect->width || !rect->height || rect->dx > vxres || rect->dy > vyres)
+		return;
+
+	/* 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 < vxres ? x2 : vxres;
+	y2 = y2 < vyres ? y2 : vyres;
+	width = x2 - rect->dx;
+
+	switch (info->fix.type) {
+	case FB_TYPE_VGA_PLANES:
+		if (info->fix.type_aux == FB_AUX_VGA_PLANES_VGA4) {
+
+			height = y2 - rect->dy;
+			width = rect->width/8;
+
+			line_ofs = info->fix.line_length - width;
+			dst = info->screen_base + (rect->dx/8) + rect->dy * info->fix.line_length;
+
+			switch (rect->rop) {
+			case ROP_COPY:
+				setmode(0);
+				setop(0);
+				setsr(0xf);
+				setcolor(rect->color);
+				selectmask();
+
+				setmask(0xff);
+
+				while (height--) {
+					for (x = 0; x < width; x++) {
+						writeb(0, dst);
+						dst++;
+					}
+					dst += line_ofs;
+				}
+				break;
+			case ROP_XOR:
+				setmode(0);
+				setop(0x18);
+				setsr(0xf);
+				setcolor(0xf);
+				selectmask();
+
+				setmask(0xff);
+				while (height--) {
+					for (x = 0; x < width; x++) {
+						rmw(dst);
+						dst++;
+					}
+					dst += line_ofs;
+				}
+				break;
+			}
+		} else
+			vga_8planes_fillrect(info, rect);
+		break;
+	case FB_TYPE_PACKED_PIXELS:
+	default:
+		cfb_fillrect(info, rect);
+		break;
+	}
+}
+
+static void vga_8planes_copyarea(struct fb_info *info, const struct fb_copyarea *area)
+{
+        char oldindex = getindex();
+        char oldmode = setmode(0x41);
+        char oldop = setop(0);
+        char oldsr = setsr(0xf);
+        int height, line_ofs, x;
+	u32 sx, dx, width;
+	char __iomem *dest;
+	char __iomem *src;
+
+        height = area->height;
+
+        sx = area->sx / 4;
+        dx = area->dx / 4;
+        width = area->width / 4;
+
+        if (area->dy < area->sy || (area->dy == area->sy && dx < sx)) {
+                line_ofs = info->fix.line_length - width;
+                dest = info->screen_base + dx + area->dy * info->fix.line_length;
+                src = info->screen_base + sx + area->sy * info->fix.line_length;
+                while (height--) {
+                        for (x = 0; x < width; x++) {
+                                readb(src);
+                                writeb(0, dest);
+                                src++;
+                                dest++;
+                        }
+                        src += line_ofs;
+                        dest += line_ofs;
+                }
+        } else {
+                line_ofs = info->fix.line_length - width;
+                dest = info->screen_base + dx + width +
+			(area->dy + height - 1) * info->fix.line_length;
+                src = info->screen_base + sx + width +
+			(area->sy + height - 1) * info->fix.line_length;
+                while (height--) {
+                        for (x = 0; x < width; x++) {
+                                --src;
+                                --dest;
+                                readb(src);
+                                writeb(0, dest);
+                        }
+                        src -= line_ofs;
+                        dest -= line_ofs;
+                }
+        }
+
+        setsr(oldsr);
+        setop(oldop);
+        setmode(oldmode);
+        setindex(oldindex);
+}
+
+static void vga16fb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
+{
+	u32 dx = area->dx, dy = area->dy, sx = area->sx, sy = area->sy;
+	int x, x2, y2, old_dx, old_dy, vxres, vyres;
+	int height, width, line_ofs;
+	char __iomem *dst = NULL;
+	char __iomem *src = NULL;
+
+	vxres = info->var.xres_virtual;
+	vyres = info->var.yres_virtual;
+
+	if (area->dx > vxres || area->sx > vxres || area->dy > vyres ||
+	    area->sy > vyres)
+		return;
+
+	/* clip the destination */
+	old_dx = area->dx;
+	old_dy = area->dy;
+
+	/*
+	 * We could use hardware clipping but on many cards you get around
+	 * hardware clipping by writing to framebuffer directly.
+	 */
+	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 < vxres ? x2 : vxres;
+	y2 = y2 < vyres ? y2 : vyres;
+	width = x2 - dx;
+	height = y2 - dy;
+
+	if (sx + dx < old_dx || sy + dy < old_dy)
+		return;
+
+	/* update sx1,sy1 */
+	sx += (dx - old_dx);
+	sy += (dy - old_dy);
+
+	/* the source must be completely inside the virtual screen */
+	if (sx + width > vxres || sy + height > vyres)
+		return;
+
+	switch (info->fix.type) {
+	case FB_TYPE_VGA_PLANES:
+		if (info->fix.type_aux == FB_AUX_VGA_PLANES_VGA4) {
+			width = width/8;
+			line_ofs = info->fix.line_length - width;
+
+			setmode(1);
+			setop(0);
+			setsr(0xf);
+
+			if (dy < sy || (dy == sy && dx < sx)) {
+				dst = info->screen_base + (dx/8) + dy * info->fix.line_length;
+				src = info->screen_base + (sx/8) + sy * info->fix.line_length;
+				while (height--) {
+					for (x = 0; x < width; x++) {
+						readb(src);
+						writeb(0, dst);
+						dst++;
+						src++;
+					}
+					src += line_ofs;
+					dst += line_ofs;
+				}
+			} else {
+				dst = info->screen_base + (dx/8) + width +
+					(dy + height - 1) * info->fix.line_length;
+				src = info->screen_base + (sx/8) + width +
+					(sy + height  - 1) * info->fix.line_length;
+				while (height--) {
+					for (x = 0; x < width; x++) {
+						dst--;
+						src--;
+						readb(src);
+						writeb(0, dst);
+					}
+					src -= line_ofs;
+					dst -= line_ofs;
+				}
+			}
+		} else
+			vga_8planes_copyarea(info, area);
+		break;
+	case FB_TYPE_PACKED_PIXELS:
+	default:
+		cfb_copyarea(info, area);
+		break;
+	}
+}
+
+#define TRANS_MASK_LOW  {0x0,0x8,0x4,0xC,0x2,0xA,0x6,0xE,0x1,0x9,0x5,0xD,0x3,0xB,0x7,0xF}
+#define TRANS_MASK_HIGH {0x000, 0x800, 0x400, 0xC00, 0x200, 0xA00, 0x600, 0xE00, \
+			 0x100, 0x900, 0x500, 0xD00, 0x300, 0xB00, 0x700, 0xF00}
+
+#if defined(__LITTLE_ENDIAN)
+static const u16 transl_l[] = TRANS_MASK_LOW;
+static const u16 transl_h[] = TRANS_MASK_HIGH;
+#elif defined(__BIG_ENDIAN)
+static const u16 transl_l[] = TRANS_MASK_HIGH;
+static const u16 transl_h[] = TRANS_MASK_LOW;
+#else
+#error "Only __BIG_ENDIAN and __LITTLE_ENDIAN are supported in vga-planes"
+#endif
+
+static void vga_8planes_imageblit(struct fb_info *info, const struct fb_image *image)
+{
+        char oldindex = getindex();
+        char oldmode = setmode(0x40);
+        char oldop = setop(0);
+        char oldsr = setsr(0);
+        char oldmask = selectmask();
+	const unsigned char *cdat = image->data;
+	u32 dx = image->dx;
+        char __iomem *where;
+        int y;
+
+        dx /= 4;
+        where = info->screen_base + dx + image->dy * info->fix.line_length;
+
+        setmask(0xff);
+        writeb(image->bg_color, where);
+        readb(where);
+        selectmask();
+        setmask(image->fg_color ^ image->bg_color);
+        setmode(0x42);
+        setop(0x18);
+        for (y = 0; y < image->height; y++, where += info->fix.line_length)
+                writew(transl_h[cdat[y]&0xF] | transl_l[cdat[y] >> 4], where);
+        setmask(oldmask);
+        setsr(oldsr);
+        setop(oldop);
+        setmode(oldmode);
+        setindex(oldindex);
+}
+
+static void vga_imageblit_expand(struct fb_info *info, const struct fb_image *image)
+{
+	char __iomem *where = info->screen_base + (image->dx/8) +
+		image->dy * info->fix.line_length;
+	struct vga16fb_par *par = info->par;
+	char *cdat = (char *) image->data;
+	char __iomem *dst;
+	int x, y;
+
+	switch (info->fix.type) {
+	case FB_TYPE_VGA_PLANES:
+		if (info->fix.type_aux == FB_AUX_VGA_PLANES_VGA4) {
+			if (par->isVGA) {
+				setmode(2);
+				setop(0);
+				setsr(0xf);
+				setcolor(image->fg_color);
+				selectmask();
+
+				setmask(0xff);
+				writeb(image->bg_color, where);
+				rmb();
+				readb(where); /* fill latches */
+				setmode(3);
+				wmb();
+				for (y = 0; y < image->height; y++) {
+					dst = where;
+					for (x = image->width/8; x--;)
+						writeb(*cdat++, dst++);
+					where += info->fix.line_length;
+				}
+				wmb();
+			} else {
+				setmode(0);
+				setop(0);
+				setsr(0xf);
+				setcolor(image->bg_color);
+				selectmask();
+
+				setmask(0xff);
+				for (y = 0; y < image->height; y++) {
+					dst = where;
+					for (x=image->width/8; x--;){
+						rmw(dst);
+						setcolor(image->fg_color);
+						selectmask();
+						if (*cdat) {
+							setmask(*cdat++);
+							rmw(dst++);
+						}
+					}
+					where += info->fix.line_length;
+				}
+			}
+		} else
+			vga_8planes_imageblit(info, image);
+		break;
+	case FB_TYPE_PACKED_PIXELS:
+	default:
+		cfb_imageblit(info, image);
+		break;
+	}
+}
+
+static void vga_imageblit_color(struct fb_info *info, const struct fb_image *image)
+{
+	/*
+	 * Draw logo
+	 */
+	struct vga16fb_par *par = info->par;
+	char __iomem *where =
+		info->screen_base + image->dy * info->fix.line_length +
+		image->dx/8;
+	const char *cdat = image->data;
+	char __iomem *dst;
+	int x, y;
+
+	switch (info->fix.type) {
+	case FB_TYPE_VGA_PLANES:
+		if (info->fix.type_aux == FB_AUX_VGA_PLANES_VGA4 &&
+		    par->isVGA) {
+			setsr(0xf);
+			setop(0);
+			setmode(0);
+
+			for (y = 0; y < image->height; y++) {
+				for (x = 0; x < image->width; x++) {
+					dst = where + x/8;
+
+					setcolor(*cdat);
+					selectmask();
+					setmask(1 << (7 - (x % 8)));
+					fb_readb(dst);
+					fb_writeb(0, dst);
+
+					cdat++;
+				}
+				where += info->fix.line_length;
+			}
+		}
+		break;
+	case FB_TYPE_PACKED_PIXELS:
+		cfb_imageblit(info, image);
+		break;
+	default:
+		break;
+	}
+}
+
+static void vga16fb_imageblit(struct fb_info *info, const struct fb_image *image)
+{
+	if (image->depth == 1)
+		vga_imageblit_expand(info, image);
+	else
+		vga_imageblit_color(info, image);
+}
+
+static void vga16fb_destroy(struct fb_info *info)
+{
+	iounmap(info->screen_base);
+	fb_dealloc_cmap(&info->cmap);
+	/* XXX unshare VGA regions */
+	framebuffer_release(info);
+}
+
+static const struct fb_ops vga16fb_ops = {
+	.owner		= THIS_MODULE,
+	.fb_open        = vga16fb_open,
+	.fb_release     = vga16fb_release,
+	__FB_DEFAULT_IOMEM_OPS_RDWR,
+	.fb_destroy	= vga16fb_destroy,
+	.fb_check_var	= vga16fb_check_var,
+	.fb_set_par	= vga16fb_set_par,
+	.fb_setcolreg 	= vga16fb_setcolreg,
+	.fb_pan_display = vga16fb_pan_display,
+	.fb_blank 	= vga16fb_blank,
+	.fb_fillrect	= vga16fb_fillrect,
+	.fb_copyarea	= vga16fb_copyarea,
+	.fb_imageblit	= vga16fb_imageblit,
+	__FB_DEFAULT_IOMEM_OPS_MMAP,
+};
+
+static int vga16fb_probe(struct platform_device *dev)
+{
+	struct sysfb_display_info *dpy;
+	struct screen_info *si;
+	struct fb_info *info;
+	struct vga16fb_par *par;
+	int i;
+	int ret = 0;
+
+	dpy = dev_get_platdata(&dev->dev);
+	if (!dpy)
+		return -ENODEV;
+	si = &dpy->screen;
+
+	ret = check_mode_supported(si);
+	if (ret)
+		return ret;
+
+	dev_dbg(&dev->dev, "initializing\n");
+	if (!request_mem_region(vga16fb_fix.smem_start, vga16fb_fix.smem_len,
+				"vga16b")) {
+		dev_err(&dev->dev, "cannot reserve video memory at 0x%lx\n",
+		       vga16fb_fix.smem_start);
+	}
+	info = framebuffer_alloc(sizeof(struct vga16fb_par), &dev->dev);
+
+	if (!info) {
+		ret = -ENOMEM;
+		goto err_fb_alloc;
+	}
+
+	/* XXX share VGA_FB_PHYS_BASE and I/O region with vgacon and others */
+	info->screen_base = (void __iomem *)VGA_MAP_MEM(VGA_FB_PHYS_BASE, 0);
+
+	if (!info->screen_base) {
+		dev_err(&dev->dev, "unable to map device\n");
+		ret = -ENOMEM;
+		goto err_ioremap;
+	}
+
+	dev_info(&dev->dev, "mapped to 0x%p\n", info->screen_base);
+	par = info->par;
+
+	par->isVGA = screen_info_video_type(si) == VIDEO_TYPE_VGAC;
+	par->palette_blanked = 0;
+	par->vesa_blanked = 0;
+
+	i = par->isVGA? 6 : 2;
+
+	vga16fb_defined.red.length   = i;
+	vga16fb_defined.green.length = i;
+	vga16fb_defined.blue.length  = i;
+
+	/* name should not depend on EGA/VGA */
+	info->fbops = &vga16fb_ops;
+	info->var = vga16fb_defined;
+	info->fix = vga16fb_fix;
+	/* supports rectangles with widths of multiples of 8 */
+	bitmap_zero(info->pixmap.blit_x, FB_MAX_BLIT_WIDTH);
+	set_bit(8 - 1, info->pixmap.blit_x);
+	set_bit(16 - 1, info->pixmap.blit_x);
+	set_bit(24 - 1, info->pixmap.blit_x);
+	set_bit(32 - 1, info->pixmap.blit_x);
+	info->flags = FBINFO_HWACCEL_YPAN;
+
+	i = (info->var.bits_per_pixel == 8) ? 256 : 16;
+	ret = fb_alloc_cmap(&info->cmap, i, 0);
+	if (ret) {
+		dev_err(&dev->dev, "unable to allocate colormap\n");
+		ret = -ENOMEM;
+		goto err_alloc_cmap;
+	}
+
+	if (vga16fb_check_var(&info->var, info)) {
+		dev_err(&dev->dev, "unable to validate variable\n");
+		ret = -EINVAL;
+		goto err_check_var;
+	}
+
+	vga16fb_update_fix(info);
+
+	ret = devm_aperture_acquire_for_platform_device(dev, VGA_FB_PHYS_BASE, VGA_FB_PHYS_SIZE);
+	if (ret)
+		goto err_check_var;
+	if (register_framebuffer(info) < 0) {
+		dev_err(&dev->dev, "unable to register framebuffer\n");
+		ret = -EINVAL;
+		goto err_check_var;
+	}
+
+	fb_info(info, "%s frame buffer device\n", info->fix.id);
+	platform_set_drvdata(dev, info);
+
+	return 0;
+
+ err_check_var:
+	fb_dealloc_cmap(&info->cmap);
+ err_alloc_cmap:
+	iounmap(info->screen_base);
+ err_ioremap:
+	framebuffer_release(info);
+ err_fb_alloc:
+	release_mem_region(vga16fb_fix.smem_start,
+		    vga16fb_fix.smem_len);
+	return ret;
+}
+
+static void vga16fb_remove(struct platform_device *dev)
+{
+	struct fb_info *info = platform_get_drvdata(dev);
+
+	if (info)
+		unregister_framebuffer(info);
+	release_mem_region(vga16fb_fix.smem_start,
+		    vga16fb_fix.smem_len);
+}
+
+static const struct platform_device_id vga16fb_driver_id_table[] = {
+	{"ega-framebuffer", 0},
+	{"vga-framebuffer", 0},
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, vga16fb_driver_id_table);
+
+static struct platform_driver vga16fb_driver = {
+	.probe = vga16fb_probe,
+	.remove = vga16fb_remove,
+	.driver = {
+		.name = "vga16fb",
+	},
+	.id_table = vga16fb_driver_id_table,
+};
+
+module_platform_driver(vga16fb_driver);
+
+MODULE_DESCRIPTION("Legacy VGA framebuffer device driver");
+MODULE_LICENSE("GPL");
-- 
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