patch-2.3.1 linux/drivers/video/acornfb.c

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diff -u --recursive --new-file v2.3.0/linux/drivers/video/acornfb.c linux/drivers/video/acornfb.c
@@ -1,15 +1,22 @@
 /*
  * linux/drivers/video/acorn.c
  *
- * Copyright (C) 1998 Russell King
+ * Copyright (C) 1998,1999 Russell King
  *
  * Frame buffer code for Acorn platforms
+ *
+ * NOTE: Most of the modes with X!=640 will disappear shortly.
+ * NOTE: Startup setting of HS & VS polarity not supported.
+ *       (do we need to support it if we're coming up in 640x480?)
  */
+
+#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/errno.h>
 #include <linux/string.h>
+#include <linux/ctype.h>
 #include <linux/mm.h>
 #include <linux/tty.h>
 #include <linux/malloc.h>
@@ -21,245 +28,898 @@
 #include <asm/irq.h>
 #include <asm/uaccess.h>
 
+#include <video/fbcon.h>
 #include <video/fbcon-mfb.h>
 #include <video/fbcon-cfb2.h>
 #include <video/fbcon-cfb4.h>
 #include <video/fbcon-cfb8.h>
+#include <video/fbcon-cfb16.h>
+
+/*
+ * Default resolution.
+ * NOTE that it has to be supported in the table towards
+ * the end of this file.
+ */
+#define DEFAULT_XRES	640
+#define DEFAULT_YRES	480
+
+/*
+ * define this to debug the video mode selection
+ */
+#undef DEBUG_MODE_SELECTION
+
+#if defined(HAS_VIDC20)
+#define VIDC_PALETTE_SIZE	256
+#define VIDC_NAME		"VIDC20"
+#elif defined(HAS_VIDC)
+#include <asm/memc.h>
+#define VIDC_PALETTE_SIZE	16
+#define VIDC_NAME		"VIDC"
+#endif
 
-#define MAX_VIDC20_PALETTE	256
-#define MAX_VIDC_PALETTE	16
+#define EXTEND8(x) ((x)|(x)<<8)
+#define EXTEND4(x) ((x)|(x)<<4|(x)<<8|(x)<<16)
+
+struct vidc20_palette {
+	u_int red:8;
+	u_int green:8;
+	u_int blue:8;
+	u_int ext:4;
+	u_int unused:4;
+};
+
+struct vidc_palette {
+	u_int red:4;
+	u_int green:4;
+	u_int blue:4;
+	u_int trans:1;
+	u_int sbz1:13;
+	u_int reg:4;
+	u_int sbz2:2;
+};
+
+union palette {
+	struct vidc20_palette	vidc20;
+	struct vidc_palette	vidc;
+	u_int	p;
+};
 
 struct acornfb_par {
-	unsigned long screen_base;
-	unsigned int xres;
-	unsigned int yres;
-	unsigned char bits_per_pixel;
-	unsigned int palette_size;
+	unsigned long	screen_base;
+	unsigned long	screen_base_p;
+	unsigned long	screen_end;
+	unsigned long	screen_size;
+	unsigned int	dram_size;
+	unsigned int	vram_half_sam;
+	unsigned int	palette_size;
+	  signed int	montype;
+	  signed int	currcon;
+	unsigned int	allow_modeset	: 1;
+	unsigned int	using_vram	: 1;
+	unsigned int	dpms		: 1;
+
+	union palette palette[VIDC_PALETTE_SIZE];
 
 	union {
-		union {
-			struct {
-				unsigned long red:8;
-				unsigned long green:8;
-				unsigned long blue:8;
-				unsigned long ext:4;
-				unsigned long unused:4;
-			} d;
-			unsigned long p;
-		} vidc20[MAX_VIDC20_PALETTE];
-		union {
-			struct {
-				unsigned long red:4;
-				unsigned long green:4;
-				unsigned long blue:4;
-				unsigned long trans:1;
-				unsigned long unused:19;
-			} d;
-			unsigned long p;
-		} vidc[MAX_VIDC_PALETTE];
-	} palette;
+		unsigned short cfb16[16];
+		unsigned long  cfb32[16];
+	} cmap;
 };
 
-static int currcon = 0;
-static struct display disp;
+/*
+ * Translation from RISC OS monitor types to actual
+ * HSYNC and VSYNC frequency ranges.  These are
+ * probably not right...
+ */
+#define NR_MONTYPES	6
+static struct fb_monspecs monspecs[NR_MONTYPES] __initdata = {
+	{ 15625, 15625, 50, 50, 0 },	/* TV		*/
+	{     0, 99999,  0, 99, 0 },	/* Multi Freq	*/
+	{ 58608, 58608, 64, 64, 0 },	/* Hi-res mono	*/
+	{ 30000, 70000, 60, 60, 0 },	/* VGA		*/
+	{ 30000, 70000, 56, 75, 0 },	/* SVGA		*/
+	{ 30000, 70000, 60, 60, 0 }
+};
+
+static struct display global_disp;
 static struct fb_info fb_info;
 static struct acornfb_par current_par;
+static struct fb_var_screeninfo __initdata init_var = {};
 
-static int
-acornfb_open(struct fb_info *info, int user)
+extern int acornfb_depth;	/* set by setup.c */
+extern unsigned int vram_size;	/* set by setup.c */
+
+
+static struct vidc_timing {
+	u_int	h_cycle;
+	u_int	h_sync_width;
+	u_int	h_border_start;
+	u_int	h_display_start;
+	u_int	h_display_end;
+	u_int	h_border_end;
+	u_int	h_interlace;
+
+	u_int	v_cycle;
+	u_int	v_sync_width;
+	u_int	v_border_start;
+	u_int	v_display_start;
+	u_int	v_display_end;
+	u_int	v_border_end;
+
+	u_int	control;
+
+	/* VIDC20 only */
+	u_int	pll_ctl;
+} current_vidc;
+
+#ifdef HAS_VIDC
+
+#define VID_CTL_VS_NVSYNC	(1 << 3)
+#define VID_CTL_HS_NHSYNC	(1 << 2)
+#define VID_CTL_24MHz		(0)
+#define VID_CTL_25MHz		(1)
+#define VID_CTL_36MHz		(2)
+
+#define VIDC_CTRL_INTERLACE	(1 << 6)
+#define VIDC_CTRL_FIFO_0_4	(0 << 4)
+#define VIDC_CTRL_FIFO_1_5	(1 << 4)
+#define VIDC_CTRL_FIFO_2_6	(2 << 4)
+#define VIDC_CTRL_FIFO_3_7	(3 << 4)
+#define VIDC_CTRL_1BPP		(0 << 2)
+#define VIDC_CTRL_2BPP		(1 << 2)
+#define VIDC_CTRL_4BPP		(2 << 2)
+#define VIDC_CTRL_8BPP		(3 << 2)
+#define VIDC_CTRL_DIV3		(0 << 0)
+#define VIDC_CTRL_DIV2		(1 << 0)
+#define VIDC_CTRL_DIV1_5	(2 << 0)
+#define VIDC_CTRL_DIV1		(3 << 0)
+
+/* CTL     VIDC	Actual
+ * 24.000  0	 8.000
+ * 25.175  0	 8.392
+ * 36.000  0	12.000
+ * 24.000  1	12.000
+ * 25.175  1	12.588
+ * 24.000  2	16.000
+ * 25.175  2	16.783
+ * 36.000  1	18.000
+ * 24.000  3	24.000
+ * 36.000  2	24.000
+ * 25.175  3	25.175
+ * 36.000  3	36.000
+ */
+static struct pixclock {
+	u_long	min_clock;
+	u_long	max_clock;
+	u_int	vidc_ctl;
+	u_int	vid_ctl;
+} pixclocks[] = {
+	/* we allow +/-1% on these */
+	{ 123750, 126250, VIDC_CTRL_DIV3,   VID_CTL_24MHz },	/*  8.000MHz */
+	{  82500,  84167, VIDC_CTRL_DIV2,   VID_CTL_24MHz },	/* 12.000MHz */
+	{  61875,  63125, VIDC_CTRL_DIV1_5, VID_CTL_24MHz },	/* 16.000MHz */
+	{  41250,  42083, VIDC_CTRL_DIV1,   VID_CTL_24MHz },	/* 24.000MHz */
+#ifdef CONFIG_ARCH_A5K
+	{ 117974, 120357, VIDC_CTRL_DIV3,   VID_CTL_25MHz },	/*  8.392MHz */
+	{  78649,  80238, VIDC_CTRL_DIV2,   VID_CTL_25MHz },	/* 12.588MHz */
+	{  58987,  60178, VIDC_CTRL_DIV1_5, VID_CTL_25MHz },	/* 16.588MHz */
+	{  55000,  56111, VIDC_CTRL_DIV2,   VID_CTL_36MHz },	/* 18.000MHz */
+	{  39325,  40119, VIDC_CTRL_DIV1,   VID_CTL_25MHz },	/* 25.175MHz */
+	{  27500,  28055, VIDC_CTRL_DIV1,   VID_CTL_36MHz },	/* 36.000MHz */
+#endif
+	{ 0, }
+};
+
+static struct pixclock *
+acornfb_valid_pixrate(u_long pixclock)
 {
-	MOD_INC_USE_COUNT;
-	return 0;
+	u_int i;
+
+	for (i = 0; pixclocks[i].min_clock; i++)
+		if (pixclock > pixclocks[i].min_clock &&
+		    pixclock < pixclocks[i].max_clock)
+			return pixclocks + i;
+
+	return NULL;
 }
 
-static int
-acornfb_release(struct fb_info *info, int user)
+/* VIDC Rules:
+ * hcr  : must be even (interlace, hcr/2 must be even)
+ * hswr : must be even
+ * hdsr : must be odd
+ * hder : must be odd
+ *
+ * vcr  : must be odd
+ * vswr : >= 1
+ * vdsr : >= 1
+ * vder : >= vdsr
+ * if interlaced, then hcr/2 must be even
+ */
+static void
+acornfb_set_timing(struct fb_var_screeninfo *var)
 {
-	MOD_DEC_USE_COUNT;
-	return 0;
+	struct pixclock *pclk;
+	struct vidc_timing vidc;
+	u_int horiz_correction;
+	u_int sync_len, display_start, display_end, cycle;
+	u_int is_interlaced;
+	u_int vid_ctl, vidc_ctl;
+	u_int bandwidth;
+
+	memset(&vidc, 0, sizeof(vidc));
+
+	pclk = acornfb_valid_pixrate(var->pixclock);
+	vidc_ctl = pclk->vidc_ctl;
+	vid_ctl  = pclk->vid_ctl;
+
+	bandwidth = var->pixclock * 8 / var->bits_per_pixel;
+	/* 25.175, 4bpp = 79.444ns per byte, 317.776ns per word: fifo = 2,6 */
+	if (bandwidth > 71750)
+		vidc_ctl |= VIDC_CTRL_FIFO_2_6;
+	else if (bandwidth > 35875)
+		vidc_ctl |= VIDC_CTRL_FIFO_1_5;
+	else
+		vidc_ctl |= VIDC_CTRL_FIFO_0_4;
+
+	switch (var->bits_per_pixel) {
+	case 1:
+		horiz_correction = 19;
+		vidc_ctl |= VIDC_CTRL_1BPP;
+		break;
+
+	case 2:
+		horiz_correction = 11;
+		vidc_ctl |= VIDC_CTRL_2BPP;
+		break;
+
+	case 4:
+		horiz_correction = 7;
+		vidc_ctl |= VIDC_CTRL_4BPP;
+		break;
+
+	default:
+	case 8:
+		horiz_correction = 5;
+		vidc_ctl |= VIDC_CTRL_8BPP;
+		break;
+	}
+
+	if (!(var->sync & FB_SYNC_HOR_HIGH_ACT))
+		vid_ctl |= VID_CTL_HS_NHSYNC;
+
+	if (!(var->sync & FB_SYNC_VERT_HIGH_ACT))
+		vid_ctl |= VID_CTL_VS_NVSYNC;
+
+	sync_len	= var->hsync_len;
+	display_start	= sync_len + var->left_margin;
+	display_end	= display_start + var->xres;
+	cycle		= display_end + var->right_margin;
+
+	/* if interlaced, then hcr/2 must be even */
+	is_interlaced = (var->vmode & FB_VMODE_MASK) == FB_VMODE_INTERLACED;
+
+	if (is_interlaced) {
+		vidc_ctl |= VIDC_CTRL_INTERLACE;
+		if (cycle & 2) {
+			cycle += 2;
+			var->right_margin += 2;
+		}
+	}
+
+	vidc.h_cycle		= (cycle - 2) / 2;
+	vidc.h_sync_width	= (sync_len - 2) / 2;
+	vidc.h_border_start	= (display_start - 1) / 2;
+	vidc.h_display_start	= (display_start - horiz_correction) / 2;
+	vidc.h_display_end	= (display_end - horiz_correction) / 2;
+	vidc.h_border_end	= (display_end - 1) / 2;
+	vidc.h_interlace	= (vidc.h_cycle + 1) / 2;
+
+	sync_len	= var->vsync_len;
+	display_start	= sync_len + var->upper_margin;
+	display_end	= display_start + var->yres;
+	cycle		= display_end + var->lower_margin;
+
+	if (is_interlaced)
+		cycle = (cycle - 3) / 2;
+	else
+		cycle = cycle - 1;
+
+	vidc.v_cycle		= cycle;
+	vidc.v_sync_width	= sync_len - 1;
+	vidc.v_border_start	= display_start - 1;
+	vidc.v_display_start	= vidc.v_border_start;
+	vidc.v_display_end	= display_end - 1;
+	vidc.v_border_end	= vidc.v_display_end;
+
+#ifdef CONFIG_ARCH_A5K
+	outb(vid_ctl, IOEB_VID_CTL);
+#endif
+	if (memcmp(&current_vidc, &vidc, sizeof(vidc))) {
+		current_vidc = vidc;
+
+		outl(0xe0000000 | vidc_ctl,			IO_VIDC_BASE);
+		outl(0x80000000 | (vidc.h_cycle << 14),		IO_VIDC_BASE);
+		outl(0x84000000 | (vidc.h_sync_width << 14),	IO_VIDC_BASE);
+		outl(0x88000000 | (vidc.h_border_start << 14),	IO_VIDC_BASE);
+		outl(0x8c000000 | (vidc.h_display_start << 14),	IO_VIDC_BASE);
+		outl(0x90000000 | (vidc.h_display_end << 14),	IO_VIDC_BASE);
+		outl(0x94000000 | (vidc.h_border_end << 14),	IO_VIDC_BASE);
+		outl(0x98000000,				IO_VIDC_BASE);
+		outl(0x9c000000 | (vidc.h_interlace << 14),	IO_VIDC_BASE);
+		outl(0xa0000000 | (vidc.v_cycle << 14),		IO_VIDC_BASE);
+		outl(0xa4000000 | (vidc.v_sync_width << 14),	IO_VIDC_BASE);
+		outl(0xa8000000 | (vidc.v_border_start << 14),	IO_VIDC_BASE);
+		outl(0xac000000 | (vidc.v_display_start << 14),	IO_VIDC_BASE);
+		outl(0xb0000000 | (vidc.v_display_end << 14),	IO_VIDC_BASE);
+		outl(0xb4000000 | (vidc.v_border_end << 14),	IO_VIDC_BASE);
+		outl(0xb8000000,				IO_VIDC_BASE);
+		outl(0xbc000000,				IO_VIDC_BASE);
+	}
+#ifdef DEBUG_MODE_SELECTION
+	printk(KERN_DEBUG "VIDC registers for %dx%dx%d:\n", var->xres,
+	       var->yres, var->bits_per_pixel);
+	printk(KERN_DEBUG " H-cycle          : %d\n", vidc.h_cycle);
+	printk(KERN_DEBUG " H-sync-width     : %d\n", vidc.h_sync_width);
+	printk(KERN_DEBUG " H-border-start   : %d\n", vidc.h_border_start);
+	printk(KERN_DEBUG " H-display-start  : %d\n", vidc.h_display_start);
+	printk(KERN_DEBUG " H-display-end    : %d\n", vidc.h_display_end);
+	printk(KERN_DEBUG " H-border-end     : %d\n", vidc.h_border_end);
+	printk(KERN_DEBUG " H-interlace      : %d\n", vidc.h_interlace);
+	printk(KERN_DEBUG " V-cycle          : %d\n", vidc.v_cycle);
+	printk(KERN_DEBUG " V-sync-width     : %d\n", vidc.v_sync_width);
+	printk(KERN_DEBUG " V-border-start   : %d\n", vidc.v_border_start);
+	printk(KERN_DEBUG " V-display-start  : %d\n", vidc.v_display_start);
+	printk(KERN_DEBUG " V-display-end    : %d\n", vidc.v_display_end);
+	printk(KERN_DEBUG " V-border-end     : %d\n", vidc.v_border_end);
+	printk(KERN_DEBUG " VIDC Ctrl (E)    : 0x%08X\n", vidc_ctl);
+	printk(KERN_DEBUG " IOEB Ctrl        : 0x%08X\n", vid_ctl);
+#endif
+}
+
+static inline void
+acornfb_palette_write(u_int regno, union palette pal)
+{
+	outl(pal.p, IO_VIDC_BASE);
+}
+
+static inline union palette
+acornfb_palette_encode(u_int regno, u_int red, u_int green, u_int blue,
+		       u_int trans)
+{
+	union palette pal;
+
+	pal.p = 0;
+	pal.vidc.reg   = regno;
+	pal.vidc.red   = red >> 12;
+	pal.vidc.green = green >> 12;
+	pal.vidc.blue  = blue >> 12;
+	return pal;
 }
 
 static void
-acornfb_encode_var(struct fb_var_screeninfo *var, struct acornfb_par *par)
+acornfb_palette_decode(u_int regno, u_int *red, u_int *green, u_int *blue,
+		       u_int *trans)
 {
-	var->xres		= par->xres;
-	var->yres		= par->yres;
-	var->xres_virtual	= par->xres;
-	var->yres_virtual	= par->yres;
-	var->xoffset		= 0;
-	var->yoffset		= 0;
-	var->bits_per_pixel	= par->bits_per_pixel;
-	var->grayscale		= 0;
-	var->red.offset		= 0;
-	var->red.length		= 8;
-	var->red.msb_right	= 0;
-	var->green.offset	= 0;
-	var->green.length	= 8;
-	var->green.msb_right	= 0;
-	var->blue.offset	= 0;
-	var->blue.length	= 8;
-	var->blue.msb_right	= 0;
-	var->transp.offset	= 0;
-	var->transp.length	= 4;
-	var->transp.msb_right	= 0;
-	var->nonstd		= 0;
-	var->activate		= FB_ACTIVATE_NOW;
-	var->height		= -1;
-	var->width		= -1;
-	var->vmode		= FB_VMODE_NONINTERLACED;
-	var->pixclock		= 1;
-	var->sync		= 0;
-	var->left_margin	= 0;
-	var->right_margin	= 0;
-	var->upper_margin	= 0;
-	var->lower_margin	= 0;
-	var->hsync_len		= 0;
-	var->vsync_len		= 0;
+	*red   = EXTEND4(current_par.palette[regno].vidc.red);
+	*green = EXTEND4(current_par.palette[regno].vidc.green);
+	*blue  = EXTEND4(current_par.palette[regno].vidc.blue);
+	*trans = current_par.palette[regno].vidc.trans ? -1 : 0;
 }
+#endif
 
-static int
-acornfb_get_fix(struct fb_fix_screeninfo *fix, int con, struct fb_info *info)
+#ifdef HAS_VIDC20
+/*
+ * VIDC20 registers
+ */
+#define VIDC20_CTRL		0xe0000000
+#define VIDC20_CTRL_PIX_VCLK	(0 << 0)
+#define VIDC20_CTRL_PIX_HCLK	(1 << 0)
+#define VIDC20_CTRL_PIX_RCLK	(2 << 0)
+#define VIDC20_CTRL_PIX_CK	(0 << 2)
+#define VIDC20_CTRL_PIX_CK2	(1 << 2)
+#define VIDC20_CTRL_PIX_CK3	(2 << 2)
+#define VIDC20_CTRL_PIX_CK4	(3 << 2)
+#define VIDC20_CTRL_PIX_CK5	(4 << 2)
+#define VIDC20_CTRL_PIX_CK6	(5 << 2)
+#define VIDC20_CTRL_PIX_CK7	(6 << 2)
+#define VIDC20_CTRL_PIX_CK8	(7 << 2)
+#define VIDC20_CTRL_1BPP	(0 << 5)
+#define VIDC20_CTRL_2BPP	(1 << 5)
+#define VIDC20_CTRL_4BPP	(2 << 5)
+#define VIDC20_CTRL_8BPP	(3 << 5)
+#define VIDC20_CTRL_16BPP	(4 << 5)
+#define VIDC20_CTRL_32BPP	(6 << 5)
+#define VIDC20_CTRL_FIFO_NS	(0 << 8)
+#define VIDC20_CTRL_FIFO_4	(1 << 8)
+#define VIDC20_CTRL_FIFO_8	(2 << 8)
+#define VIDC20_CTRL_FIFO_12	(3 << 8)
+#define VIDC20_CTRL_FIFO_16	(4 << 8)
+#define VIDC20_CTRL_FIFO_20	(5 << 8)
+#define VIDC20_CTRL_FIFO_24	(6 << 8)
+#define VIDC20_CTRL_FIFO_28	(7 << 8)
+#define VIDC20_CTRL_INT		(1 << 12)
+#define VIDC20_CTRL_DUP		(1 << 13)
+#define VIDC20_CTRL_PDOWN	(1 << 14)
+
+#define VIDC20_ECTL		0xc0000000
+#define VIDC20_ECTL_REG(x)	((x) & 0xf3)
+#define VIDC20_ECTL_ECK		(1 << 2)
+#define VIDC20_ECTL_REDPED	(1 << 8)
+#define VIDC20_ECTL_GREENPED	(1 << 9)
+#define VIDC20_ECTL_BLUEPED	(1 << 10)
+#define VIDC20_ECTL_DAC		(1 << 12)
+#define VIDC20_ECTL_LCDGS	(1 << 13)
+#define VIDC20_ECTL_HRM		(1 << 14)
+
+#define VIDC20_ECTL_HS_MASK	(3 << 16)
+#define VIDC20_ECTL_HS_HSYNC	(0 << 16)
+#define VIDC20_ECTL_HS_NHSYNC	(1 << 16)
+#define VIDC20_ECTL_HS_CSYNC	(2 << 16)
+#define VIDC20_ECTL_HS_NCSYNC	(3 << 16)
+
+#define VIDC20_ECTL_VS_MASK	(3 << 18)
+#define VIDC20_ECTL_VS_VSYNC	(0 << 18)
+#define VIDC20_ECTL_VS_NVSYNC	(1 << 18)
+#define VIDC20_ECTL_VS_CSYNC	(2 << 18)
+#define VIDC20_ECTL_VS_NCSYNC	(3 << 18)
+
+#define VIDC20_DCTL		0xf0000000
+/* 0-9 = number of words in scanline */
+#define VIDC20_DCTL_SNA		(1 << 12)
+#define VIDC20_DCTL_HDIS	(1 << 13)
+#define VIDC20_DCTL_BUS_NS	(0 << 16)
+#define VIDC20_DCTL_BUS_D31_0	(1 << 16)
+#define VIDC20_DCTL_BUS_D63_32	(2 << 16)
+#define VIDC20_DCTL_BUS_D63_0	(3 << 16)
+#define VIDC20_DCTL_VRAM_DIS	(0 << 18)
+#define VIDC20_DCTL_VRAM_PXCLK	(1 << 18)
+#define VIDC20_DCTL_VRAM_PXCLK2	(2 << 18)
+#define VIDC20_DCTL_VRAM_PXCLK4	(3 << 18)
+
+#define acornfb_valid_pixrate(rate) (1)
+
+/*
+ * Try to find the best PLL parameters for the pixel clock.
+ * This algorithm seems to give best predictable results,
+ * and produces the same values as detailed in the VIDC20
+ * data sheet.
+ */
+static inline u_int
+acornfb_vidc20_find_pll(u_int pixclk)
 {
-	struct acornfb_par *par = &current_par;
-	unsigned int line_length;
+	u_int r, best_r = 2, best_v = 2;
+	int best_d = 0x7fffffff;
 
-	memset(fix, 0, sizeof(struct fb_fix_screeninfo));
-	strcpy(fix->id, "Acorn");
+	for (r = 2; r <= 32; r++) {
+		u_int rr, v, p;
+		int d;
 
-	line_length = par->xres * par->bits_per_pixel / 8;
+		rr = 41667 * r;
 
-	fix->smem_start	 = (char *)SCREEN2_BASE;
-	fix->smem_len	 = (((line_length * par->yres) - 1) | (PAGE_SIZE - 1)) + 1;
-	fix->type	 = FB_TYPE_PACKED_PIXELS;
-	fix->type_aux	 = 0;
-	fix->visual	 = FB_VISUAL_PSEUDOCOLOR;
-	fix->xpanstep	 = 0;
-	fix->ypanstep	 = 0;
-	fix->ywrapstep	 = 1;
-	fix->line_length = line_length;
-	fix->accel	 = FB_ACCEL_NONE;
+		v = (rr + pixclk / 2) / pixclk;
 
-	return 0;
+		if (v > 32 || v < 2)
+			continue;
+
+		p = (rr + v / 2) / v;
+
+		d = pixclk - p;
+
+		if (d < 0)
+			d = -d;
+
+		if (d < best_d) {
+			best_d = d;
+			best_v = v - 1;
+			best_r = r - 1;
+		}
+
+		if (d == 0)
+			break;
+	}
+
+	return best_v << 8 | best_r;
 }
 
-static int
-acornfb_get_var(struct fb_var_screeninfo *var, int con, struct fb_info *info)
+static inline void
+acornfb_vidc20_find_rates(struct vidc_timing *vidc,
+			  struct fb_var_screeninfo *var)
 {
-	if (con == -1) {
-		acornfb_encode_var(var, &current_par);
+	u_int div, bandwidth;
+
+	/* Select pixel-clock divisor to keep PLL in range */
+	div = var->pixclock / 9090; /*9921*/
+
+	/* Limit divisor */
+	if (div == 0)
+		div = 1;
+	if (div > 8)
+		div = 8;
+
+	/* Encode divisor to VIDC20 setting */
+	switch (div) {
+	case 1:	vidc->control |= VIDC20_CTRL_PIX_CK;  break;
+	case 2:	vidc->control |= VIDC20_CTRL_PIX_CK2; break;
+	case 3:	vidc->control |= VIDC20_CTRL_PIX_CK3; break;
+	case 4:	vidc->control |= VIDC20_CTRL_PIX_CK4; break;
+	case 5:	vidc->control |= VIDC20_CTRL_PIX_CK5; break;
+	case 6:	vidc->control |= VIDC20_CTRL_PIX_CK6; break;
+	case 7:	vidc->control |= VIDC20_CTRL_PIX_CK7; break;
+	case 8: vidc->control |= VIDC20_CTRL_PIX_CK8; break;
+	}
+
+	/* Calculate bandwidth */
+	bandwidth = var->pixclock * 8 / var->bits_per_pixel;
+
+	/* Encode bandwidth as VIDC20 setting */
+	if (bandwidth > 16667*2)
+		vidc->control |= VIDC20_CTRL_FIFO_16;
+	else if (bandwidth > 13333*2)
+		vidc->control |= VIDC20_CTRL_FIFO_20;
+	else if (bandwidth > 11111*2)
+		vidc->control |= VIDC20_CTRL_FIFO_24;
+	else
+		vidc->control |= VIDC20_CTRL_FIFO_28;
+
+	/* Find the PLL values */
+	vidc->pll_ctl  = acornfb_vidc20_find_pll(var->pixclock / div);
+}
+
+/* VIDC20 has a different set of rules from the VIDC:
+ *  hcr  : must be multiple of 4
+ *  hswr : must be even
+ *  hdsr : must be even
+ *  hder : must be even
+ *  vcr  : >= 2, (interlace, must be odd)
+ *  vswr : >= 1
+ *  vdsr : >= 1
+ *  vder : >= vdsr
+ */
+static void
+acornfb_set_timing(struct fb_var_screeninfo *var)
+{
+	struct vidc_timing vidc;
+	u_int vcr, fsize;
+	u_int ext_ctl, dat_ctl;
+	u_int words_per_line;
+
+	memset(&vidc, 0, sizeof(vidc));
+
+	vidc.h_sync_width	= var->hsync_len - 8;
+	vidc.h_border_start	= vidc.h_sync_width + var->left_margin + 8 - 12;
+	vidc.h_display_start	= vidc.h_border_start + 12 - 18;
+	vidc.h_display_end	= vidc.h_display_start + var->xres;
+	vidc.h_border_end	= vidc.h_display_end + 18 - 12;
+	vidc.h_cycle		= vidc.h_border_end + var->right_margin + 12 - 8;
+	vidc.h_interlace	= vidc.h_cycle / 2;
+	vidc.v_sync_width	= var->vsync_len - 1;
+	vidc.v_border_start	= vidc.v_sync_width + var->upper_margin;
+	vidc.v_display_start	= vidc.v_border_start;
+	vidc.v_display_end	= vidc.v_display_start + var->yres;
+	vidc.v_border_end	= vidc.v_display_end;
+	vidc.control		= VIDC20_CTRL_PIX_VCLK;
+
+	vcr = var->vsync_len + var->upper_margin + var->yres +
+	      var->lower_margin;
+
+	if ((var->vmode & FB_VMODE_MASK) == FB_VMODE_INTERLACED) {
+		vidc.v_cycle = (vcr - 3) / 2;
+		vidc.control |= VIDC20_CTRL_INT;
 	} else
-		*var = fb_display[con].var;
-	return 0;
+		vidc.v_cycle = vcr - 2;
+
+	switch (var->bits_per_pixel) {
+	case  1: vidc.control |= VIDC20_CTRL_1BPP;	break;
+	case  2: vidc.control |= VIDC20_CTRL_2BPP;	break;
+	case  4: vidc.control |= VIDC20_CTRL_4BPP;	break;
+	default:
+	case  8: vidc.control |= VIDC20_CTRL_8BPP;	break;
+	case 16: vidc.control |= VIDC20_CTRL_16BPP;	break;
+	case 32: vidc.control |= VIDC20_CTRL_32BPP;	break;
+	}
+
+	acornfb_vidc20_find_rates(&vidc, var);
+	fsize = var->vsync_len + var->upper_margin + var->lower_margin - 1;
+
+	if (memcmp(&current_vidc, &vidc, sizeof(vidc))) {
+		current_vidc = vidc;
+
+		outl(VIDC20_CTRL| vidc.control,		IO_VIDC_BASE);
+		outl(0xd0000000 | vidc.pll_ctl,		IO_VIDC_BASE);
+		outl(0x80000000 | vidc.h_cycle,		IO_VIDC_BASE);
+		outl(0x81000000 | vidc.h_sync_width,	IO_VIDC_BASE);
+		outl(0x82000000 | vidc.h_border_start,	IO_VIDC_BASE);
+		outl(0x83000000 | vidc.h_display_start,	IO_VIDC_BASE);
+		outl(0x84000000 | vidc.h_display_end,	IO_VIDC_BASE);
+		outl(0x85000000 | vidc.h_border_end,	IO_VIDC_BASE);
+		outl(0x86000000,			IO_VIDC_BASE);
+		outl(0x87000000 | vidc.h_interlace,	IO_VIDC_BASE);
+		outl(0x90000000 | vidc.v_cycle,		IO_VIDC_BASE);
+		outl(0x91000000 | vidc.v_sync_width,	IO_VIDC_BASE);
+		outl(0x92000000 | vidc.v_border_start,	IO_VIDC_BASE);
+		outl(0x93000000 | vidc.v_display_start,	IO_VIDC_BASE);
+		outl(0x94000000 | vidc.v_display_end,	IO_VIDC_BASE);
+		outl(0x95000000 | vidc.v_border_end,	IO_VIDC_BASE);
+		outl(0x96000000,			IO_VIDC_BASE);
+		outl(0x97000000,			IO_VIDC_BASE);
+	}
+
+	outl(fsize, IOMD_FSIZE);
+
+	ext_ctl = VIDC20_ECTL_DAC | VIDC20_ECTL_REG(3);
+
+	if (var->sync & FB_SYNC_HOR_HIGH_ACT)
+		ext_ctl |= VIDC20_ECTL_HS_HSYNC;
+	else
+		ext_ctl |= VIDC20_ECTL_HS_NHSYNC;
+
+	if (var->sync & FB_SYNC_VERT_HIGH_ACT)
+		ext_ctl |= VIDC20_ECTL_VS_VSYNC;
+	else
+		ext_ctl |= VIDC20_ECTL_VS_NVSYNC;
+
+	outl(VIDC20_ECTL | ext_ctl, IO_VIDC_BASE);
+
+	words_per_line = var->xres * var->bits_per_pixel / 32;
+
+	if (current_par.using_vram && current_par.screen_size == 2048*1024)
+		words_per_line /= 2;
+
+	/* RiscPC doesn't use the VIDC's VRAM control. */
+	dat_ctl = VIDC20_DCTL_VRAM_DIS | VIDC20_DCTL_SNA | words_per_line;
+
+	/* The data bus width is dependent on both the type
+	 * and amount of video memory.
+	 *     DRAM	32bit low
+	 * 1MB VRAM	32bit
+	 * 2MB VRAM	64bit
+	 */
+	if (current_par.using_vram && current_par.vram_half_sam == 2048) {
+		dat_ctl |= VIDC20_DCTL_BUS_D63_0;
+	} else 
+		dat_ctl |= VIDC20_DCTL_BUS_D31_0;
+
+	outl(VIDC20_DCTL | dat_ctl, IO_VIDC_BASE);
+
+#ifdef DEBUG_MODE_SELECTION
+	printk(KERN_DEBUG "VIDC registers for %dx%dx%d:\n", var->xres,
+	       var->yres, var->bits_per_pixel);
+	printk(KERN_DEBUG " H-cycle          : %d\n", vidc.h_cycle);
+	printk(KERN_DEBUG " H-sync-width     : %d\n", vidc.h_sync_width);
+	printk(KERN_DEBUG " H-border-start   : %d\n", vidc.h_border_start);
+	printk(KERN_DEBUG " H-display-start  : %d\n", vidc.h_display_start);
+	printk(KERN_DEBUG " H-display-end    : %d\n", vidc.h_display_end);
+	printk(KERN_DEBUG " H-border-end     : %d\n", vidc.h_border_end);
+	printk(KERN_DEBUG " H-interlace      : %d\n", vidc.h_interlace);
+	printk(KERN_DEBUG " V-cycle          : %d\n", vidc.v_cycle);
+	printk(KERN_DEBUG " V-sync-width     : %d\n", vidc.v_sync_width);
+	printk(KERN_DEBUG " V-border-start   : %d\n", vidc.v_border_start);
+	printk(KERN_DEBUG " V-display-start  : %d\n", vidc.v_display_start);
+	printk(KERN_DEBUG " V-display-end    : %d\n", vidc.v_display_end);
+	printk(KERN_DEBUG " V-border-end     : %d\n", vidc.v_border_end);
+	printk(KERN_DEBUG " Ext Ctrl  (C)    : 0x%08X\n", ext_ctl);
+	printk(KERN_DEBUG " PLL Ctrl  (D)    : 0x%08X\n", vidc.pll_ctl);
+	printk(KERN_DEBUG " Ctrl      (E)    : 0x%08X\n", vidc.control);
+	printk(KERN_DEBUG " Data Ctrl (F)    : 0x%08X\n", dat_ctl);
+	printk(KERN_DEBUG " Fsize            : 0x%08X\n", fsize);
+#endif
 }
 
-static int
-acornfb_set_var(struct fb_var_screeninfo *var, int con, struct fb_info *info)
+static inline void
+acornfb_palette_write(u_int regno, union palette pal)
 {
-	return 0;
+	outl(0x10000000 | regno, IO_VIDC_BASE);
+	outl(pal.p, IO_VIDC_BASE);
+}
+
+static inline union palette
+acornfb_palette_encode(u_int regno, u_int red, u_int green, u_int blue,
+		       u_int trans)
+{
+	union palette pal;
+
+	pal.p = 0;
+	pal.vidc20.red   = red >> 8;
+	pal.vidc20.green = green >> 8;
+	pal.vidc20.blue  = blue >> 8;
+	return pal;
 }
 
 static void
-acornfb_set_disp(int con)
+acornfb_palette_decode(u_int regno, u_int *red, u_int *green, u_int *blue,
+		       u_int *trans)
 {
-	struct fb_fix_screeninfo fix;
-	struct display *display;
+	*red   = EXTEND8(current_par.palette[regno].vidc20.red);
+	*green = EXTEND8(current_par.palette[regno].vidc20.green);
+	*blue  = EXTEND8(current_par.palette[regno].vidc20.blue);
+	*trans = EXTEND4(current_par.palette[regno].vidc20.ext);
+}
+#endif
 
-	if (con >= 0)
-		display = &fb_display[con];
+/*
+ * Before selecting the timing parameters, adjust
+ * the resolution to fit the rules.
+ */
+static void
+acornfb_pre_adjust_timing(struct fb_var_screeninfo *var, int con)
+{
+	u_int font_line_len;
+	u_int fontht;
+	u_int sam_size, min_size, size;
+	u_int nr_y;
+
+	/* xres must be even */
+	var->xres = (var->xres + 1) & ~1;
+
+	/*
+	 * We don't allow xres_virtual to differ from xres
+	 */
+	var->xres_virtual = var->xres;
+	var->xoffset = 0;
+
+	/*
+	 * Find the font height
+	 */
+	if (con == -1)
+		fontht = fontheight(&global_disp);
 	else
-		display = &disp;
+		fontht = fontheight(fb_display + con);
 
-	current_par.xres = 8 * ORIG_VIDEO_COLS;
-	current_par.yres = 8 * ORIG_VIDEO_LINES;
-	current_par.bits_per_pixel = 8;
-	current_par.palette_size = MAX_VIDC20_PALETTE;
-
-	acornfb_get_fix(&fix, con, 0);
-
-	acornfb_get_var(&display->var, con, 0);
-
-	display->cmap.start	= 0;
-	display->cmap.len	= 0;
-	display->cmap.red	= NULL;
-	display->cmap.green	= NULL;
-	display->cmap.blue	= NULL;
-	display->cmap.transp	= NULL;
-	display->screen_base	= fix.smem_start;
-	display->visual		= fix.visual;
-	display->type		= fix.type;
-	display->type_aux	= fix.type_aux;
-	display->ypanstep	= fix.ypanstep;
-	display->ywrapstep	= fix.ywrapstep;
-	display->line_length	= fix.line_length;
-	display->can_soft_blank	= 0;
-	display->inverse	= 0;
+	if (fontht == 0)
+		fontht = 8;
 
-	outl(SCREEN_START, VDMA_START);
-	outl(SCREEN_START + fix.smem_len - VDMA_XFERSIZE, VDMA_END);
-	outl(SCREEN_START, VDMA_INIT);
+	if (current_par.using_vram)
+		sam_size = current_par.vram_half_sam * 2;
+	else
+		sam_size = 16;
 
-	switch (display->var.bits_per_pixel) {
-#ifdef FBCON_HAS_MFB
-	case 1:
-		display->dispsw = &fbcon_mfb;
-		break;
-#endif
-#ifdef FBCON_HAS_CFB2
-	case 2:
-		display->dispsw = &fbcon_cfb2;
-		break;
-#endif
-#ifdef FBCON_HAS_CFB4
-	case 4:
-		display->dispsw = &fbcon_cfb4;
-		break;
+	/*
+	 * Now, find a value for yres_virtual which allows
+	 * us to do ywrap scrolling.  The value of
+	 * yres_virtual must be such that the end of the
+	 * displayable frame buffer must be aligned with
+	 * the start of a font line.
+	 */
+	font_line_len = var->xres * var->bits_per_pixel * fontht / 8;
+	min_size = var->xres * var->yres * var->bits_per_pixel / 8;
+
+	/* Find int 'y', such that y * fll == s * sam < maxsize
+	 * y = s * sam / fll; s = maxsize / sam
+	 */
+	for (size = current_par.screen_size; min_size <= size;
+	     size -= sam_size) {
+		nr_y = size / font_line_len;
+
+		if (nr_y * font_line_len == size)
+			break;
+	}
+
+	if (min_size > size) {
+		/*
+		 * failed, use ypan
+		 */
+		size = current_par.screen_size;
+		var->yres_virtual = size / (font_line_len / fontht);
+	} else
+		var->yres_virtual = nr_y * fontht;
+
+	current_par.screen_end = current_par.screen_base_p + size;
+
+	/*
+	 * Fix yres & yoffset if needed.
+	 */
+	if (var->yres > var->yres_virtual)
+		var->yres = var->yres_virtual;
+
+	if (var->vmode & FB_VMODE_YWRAP) {
+		if (var->yoffset > var->yres_virtual)
+			var->yoffset = var->yres_virtual;
+	} else {
+		if (var->yoffset + var->yres > var->yres_virtual)
+			var->yoffset = var->yres_virtual - var->yres;
+	}
+}
+
+/*
+ * After selecting the timing parameters, adjust
+ * the timing to suit the chip.
+ * NOTE! Only minor adjustments should be made here.
+ */
+static void
+acornfb_post_adjust_timing(struct fb_var_screeninfo *var)
+{
+	/* hsync_len must be even */
+	var->hsync_len = (var->hsync_len + 1) & ~1;
+
+#ifdef HAS_VIDC
+	/* left_margin must be odd */
+	if ((var->left_margin & 1) == 0) {
+		var->left_margin -= 1;
+		var->right_margin += 1;
+	}
+
+	/* right_margin must be odd */
+	var->right_margin |= 1;
+#elif defined(HAS_VIDC20)
+	/* left_margin must be even */
+	if (var->left_margin & 1) {
+		var->left_margin += 1;
+		var->right_margin -= 1;
+	}
+
+	/* right_margin must be even */
+	if (var->right_margin & 1)
+		var->right_margin += 1;
 #endif
-#ifdef FBCON_HAS_CFB8
-	case 8:
-		display->dispsw = &fbcon_cfb8;
-		break;
+
+	if (var->vsync_len < 1)
+		var->vsync_len = 1;
+}
+
+static inline void
+acornfb_update_dma(struct fb_var_screeninfo *var)
+{
+	int off = (var->yoffset * var->xres_virtual *
+		   var->bits_per_pixel) >> 3;
+
+#if defined(HAS_MEMC)
+	memc_write(VDMA_INIT, off >> 2);
+#elif defined(HAS_IOMD)
+	outl(current_par.screen_base_p + off, IOMD_VIDINIT);
 #endif
-	default:
-		display->dispsw = &fbcon_dummy;
-		break;
-	}
 }
 
 static int
-acornfb_vidc20_getcolreg(u_int regno, u_int *red, u_int *green, u_int *blue, u_int *trans, struct fb_info *info)
+acornfb_open(struct fb_info *info, int user)
 {
-	int t;
+	MOD_INC_USE_COUNT;
+	return 0;
+}
+
+static int
+acornfb_release(struct fb_info *info, int user)
+{
+	MOD_DEC_USE_COUNT;
+	return 0;
+}
 
+static int
+acornfb_getcolreg(u_int regno, u_int *red, u_int *green, u_int *blue,
+		  u_int *trans, struct fb_info *info)
+{
 	if (regno >= current_par.palette_size)
 		return 1;
-	t = current_par.palette.vidc20[regno].d.red;
-	*red = (t << 8) | t;
-	t = current_par.palette.vidc20[regno].d.green;
-	*green = (t << 8) | t;
-	t = current_par.palette.vidc20[regno].d.blue;
-	*blue = (t << 8) | t;
-	t = current_par.palette.vidc20[regno].d.ext;
-	t |= t << 4;
-	*transp = (t << 8) | t;
+
+	acornfb_palette_decode(regno, red, green, blue, trans);
+
 	return 0;
 }
 
 static int
-acornfb_vidc20_setcolreg(u_int regno, u_int red, u_int green, u_int blue, u_int trans, struct fb_info *info)
+acornfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
+		  u_int trans, struct fb_info *info)
 {
+	union palette pal;
+
 	if (regno >= current_par.palette_size)
 		return 1;
 
-	red >>= 8;
-	green >>= 8;
-	blue >>= 8;
-	current_par.palette.vidc20[regno].p = 0;
-	current_par.palette.vidc20[regno].d.red   = red;
-	current_par.palette.vidc20[regno].d.green = green;
-	current_par.palette.vidc20[regno].d.blue  = blue;
+	pal = acornfb_palette_encode(regno, red, green, blue, trans);
+	acornfb_palette_write(regno, pal);
+	current_par.palette[regno] = pal;
+
+	if (regno < 16) {
+		switch (info->disp->var.bits_per_pixel) {
+#ifdef FBCON_HAS_CFB16
+		case 16:	/* RGB555 */
+			current_par.cmap.cfb16[regno] = (regno << 10) | (regno << 5) | regno;
+			break;
+#endif
 
-	outl(0x10000000 | regno, VIDC_BASE);
-	outl(current_par.palette.vidc20[regno].p, VIDC_BASE);
+		default:
+			break;
+		}
+	}
 
 	return 0;
 }
@@ -270,8 +930,8 @@
 {
 	int err = 0;
 
-	if (con == currcon)
-		err = fb_get_cmap(cmap, kspc, acornfb_vidc20_getcolreg, info);
+	if (con == current_par.currcon)
+		err = fb_get_cmap(cmap, kspc, acornfb_getcolreg, info);
 	else if (fb_display[con].cmap.len)
 		fb_copy_cmap(&fb_display[con].cmap, cmap, kspc ? 0 : 2);
 	else
@@ -290,8 +950,8 @@
 		err = fb_alloc_cmap(&fb_display[con].cmap,
 				    current_par.palette_size, 0);
 	if (!err) {
-		if (con == currcon)
-			err = fb_set_cmap(cmap, kspc, acornfb_vidc20_setcolreg,
+		if (con == current_par.currcon)
+			err = fb_set_cmap(cmap, kspc, acornfb_setcolreg,
 					  info);
 		else
 			fb_copy_cmap(cmap, &fb_display[con].cmap,
@@ -301,13 +961,279 @@
 }
 
 static int
+acornfb_decode_var(struct fb_var_screeninfo *var, int con, int *visual)
+{
+	switch (var->bits_per_pixel) {
+#ifdef FBCON_HAS_MFB
+	case 1:
+		*visual = FB_VISUAL_MONO10;
+		break;
+#endif
+#ifdef FBCON_HAS_CFB8
+	case 8:
+#ifdef HAS_VIDC
+		*visual = FB_VISUAL_STATIC_PSEUDOCOLOR;
+#else
+		*visual = FB_VISUAL_PSEUDOCOLOR;
+#endif
+		break;
+#endif
+#ifdef FBCON_HAS_CFB4
+	case 4:
+		*visual = FB_VISUAL_PSEUDOCOLOR;
+		break;
+#endif
+#ifdef FBCON_HAS_CFB2
+	case 2:
+		*visual = FB_VISUAL_PSEUDOCOLOR;
+		break;
+#endif
+	case 16:
+	case 24:
+	case 32:
+		*visual = FB_VISUAL_TRUECOLOR;
+	default:
+		return -EINVAL;
+	}
+
+	if (!acornfb_valid_pixrate(var->pixclock))
+		return -EINVAL;
+
+	/*
+	 * Adjust the resolution before using it.
+	 */
+	acornfb_pre_adjust_timing(var, con);
+
+#if defined(HAS_VIDC20)
+	var->red.length	   = 8;
+	var->transp.length = 4;
+#elif defined(HAS_VIDC)
+	var->red.length	   = 4;
+	var->transp.length = 1;
+#endif
+	var->green = var->red;
+	var->blue  = var->red;
+
+	/*
+	 * Now adjust the timing parameters
+	 */
+	acornfb_post_adjust_timing(var);
+
+	return 0;
+}
+
+static int
+acornfb_get_fix(struct fb_fix_screeninfo *fix, int con, struct fb_info *info)
+{
+	struct display *display;
+
+	memset(fix, 0, sizeof(struct fb_fix_screeninfo));
+	strcpy(fix->id, "Acorn");
+
+	if (con >= 0)
+		display = fb_display + con;
+	else
+		display = &global_disp;
+
+	fix->smem_start	 = (char *)current_par.screen_base_p;
+	fix->smem_len	 = current_par.screen_size;
+	fix->type	 = display->type;
+	fix->type_aux	 = display->type_aux;
+	fix->xpanstep	 = 0;
+	fix->ypanstep	 = display->ypanstep;
+	fix->ywrapstep	 = display->ywrapstep;
+	fix->visual	 = display->visual;
+	fix->line_length = display->line_length;
+	fix->accel	 = FB_ACCEL_NONE;
+
+	return 0;
+}
+
+static int
+acornfb_get_var(struct fb_var_screeninfo *var, int con, struct fb_info *info)
+{
+	if (con == -1) {
+		*var = global_disp.var;
+	} else
+		*var = fb_display[con].var;
+
+	return 0;
+}
+
+static int
+acornfb_set_var(struct fb_var_screeninfo *var, int con, struct fb_info *info)
+{
+	struct display *display;
+	int err, chgvar = 0, visual;
+
+	if (con >= 0)
+		display = fb_display + con;
+	else
+		display = &global_disp;
+
+	if (!current_par.allow_modeset && con != -1)
+		return -EINVAL;
+
+	err = acornfb_decode_var(var, con, &visual);
+	if (err)
+		return err;
+
+	switch (var->activate & FB_ACTIVATE_MASK) {
+	case FB_ACTIVATE_TEST:
+		return 0;
+
+	case FB_ACTIVATE_NXTOPEN:
+	case FB_ACTIVATE_NOW:
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	if (con >= 0) {
+		if (display->var.xres != var->xres)
+			chgvar = 1;
+		if (display->var.yres != var->yres)
+			chgvar = 1;
+		if (display->var.xres_virtual != var->xres_virtual)
+			chgvar = 1;
+		if (display->var.yres_virtual != var->yres_virtual)
+			chgvar = 1;
+		if (memcmp(&display->var.red, &var->red, sizeof(var->red)))
+			chgvar = 1;
+		if (memcmp(&display->var.green, &var->green, sizeof(var->green)))
+			chgvar = 1;
+		if (memcmp(&display->var.blue, &var->blue, sizeof(var->blue)))
+			chgvar = 1;
+	}
+
+	display->var = *var;
+	display->var.activate &= ~FB_ACTIVATE_ALL;
+
+	if (var->activate & FB_ACTIVATE_ALL)
+		global_disp.var = display->var;
+
+	display->screen_base	= (char *)current_par.screen_base;
+	display->visual		= visual;
+	display->type		= FB_TYPE_PACKED_PIXELS;
+	display->type_aux	= 0;
+	display->ypanstep	= 1;
+	display->ywrapstep	= 1;
+	display->line_length	=
+	display->next_line      = (var->xres * var->bits_per_pixel) / 8;
+	display->can_soft_blank	= visual == FB_VISUAL_PSEUDOCOLOR ? 1 : 0;
+	display->inverse	= 0;
+
+	switch (display->var.bits_per_pixel) {
+#ifdef FBCON_HAS_MFB
+	case 1:
+		current_par.palette_size = 2;
+		display->dispsw = &fbcon_mfb;
+		break;
+#endif
+#ifdef FBCON_HAS_CFB2
+	case 2:
+		current_par.palette_size = 4;
+		display->dispsw = &fbcon_cfb2;
+		break;
+#endif
+#ifdef FBCON_HAS_CFB4
+	case 4:
+		current_par.palette_size = 16;
+		display->dispsw = &fbcon_cfb4;
+		break;
+#endif
+#ifdef FBCON_HAS_CFB8
+	case 8:
+		current_par.palette_size = VIDC_PALETTE_SIZE;
+		display->dispsw = &fbcon_cfb8;
+		break;
+#endif
+#ifdef FBCON_HAS_CFB16
+	case 16:
+		current_par.palette_size = VIDC_PALETTE_SIZE;
+		display->dispsw = &fbcon_cfb16;
+		display->dispsw_data = current_par.cmap.cfb16;
+		break;
+#endif
+	default:
+		display->dispsw = &fbcon_dummy;
+		break;
+	}
+
+	if (chgvar && info && info->changevar)
+		info->changevar(con);
+
+	if (con == current_par.currcon) {
+		struct fb_cmap *cmap;
+		unsigned long start, size;
+		int control;
+
+#if defined(HAS_MEMC)
+		start   = 0;
+		size    = current_par.screen_size - VDMA_XFERSIZE;
+		control = 0;
+
+		memc_write(VDMA_START, start);
+		memc_write(VDMA_END, size >> 2);
+#elif defined(HAS_IOMD)
+
+		start = current_par.screen_base_p;
+		size  = current_par.screen_end;
+
+		if (current_par.using_vram) {
+			size -= current_par.vram_half_sam;
+			control = DMA_CR_E | (current_par.vram_half_sam / 256);
+		} else {
+			size -= 16;
+			control = DMA_CR_E | DMA_CR_D | 16;
+		}
+
+		outl(start,   IOMD_VIDSTART);
+		outl(size,    IOMD_VIDEND);
+		outl(control, IOMD_VIDCR);
+#endif
+		acornfb_update_dma(var);
+
+		if (current_par.allow_modeset)
+			acornfb_set_timing(var);
+
+		if (display->cmap.len)
+			cmap = &display->cmap;
+		else
+			cmap = fb_default_cmap(current_par.palette_size);
+
+		fb_set_cmap(cmap, 1, acornfb_setcolreg, info);
+	}
+	return 0;
+}
+
+static int
 acornfb_pan_display(struct fb_var_screeninfo *var, int con,
 		    struct fb_info *info)
 {
-	if (var->xoffset || var->yoffset)
+	u_int y_bottom;
+
+	if (var->xoffset)
 		return -EINVAL;
+
+	y_bottom = var->yoffset;
+
+	if (!(var->vmode & FB_VMODE_YWRAP))
+		y_bottom += var->yres;
+
+	if (y_bottom > fb_display[con].var.yres_virtual)
+		return -EINVAL;
+
+	acornfb_update_dma(var);
+
+	fb_display[con].var.yoffset = var->yoffset;
+	if (var->vmode & FB_VMODE_YWRAP)
+		fb_display[con].var.vmode |= FB_VMODE_YWRAP;
 	else
-		return 0;
+		fb_display[con].var.vmode &= ~FB_VMODE_YWRAP;
+
+	return 0;
 }
 
 static int
@@ -329,64 +1255,652 @@
 	acornfb_ioctl
 };
 
-void
-acornfb_setup(char *options, int *ints)
+static int
+acornfb_updatevar(int con, struct fb_info *info)
 {
+	if (con == current_par.currcon)
+		acornfb_update_dma(&fb_display[con].var);
+
+	return 0;
 }
 
 static int
-acornfb_update_var(int con, struct fb_info *info)
+acornfb_switch(int con, struct fb_info *info)
 {
-	if (con == currcon) {
-		int off = fb_display[con].var.yoffset *
-			  fb_display[con].var.xres_virtual *
-			  fb_display[con].var.bits_per_pixel >> 3;
-		unsigned long base;
+	struct fb_cmap *cmap;
 
-		base = current_par.screen_base = SCREEN_START + off;
+	if (current_par.currcon >= 0) {
+		cmap = &fb_display[current_par.currcon].cmap;
 
-		outl (SCREEN_START + base, VDMA_INIT);
+		if (cmap->len)
+			fb_get_cmap(cmap, 1, acornfb_getcolreg, info);
 	}
 
-	return 0;
-}
+	current_par.currcon = con;
+
+	fb_display[con].var.activate = FB_ACTIVATE_NOW;
+
+	acornfb_set_var(&fb_display[con].var, con, info);
 
-static int
-acornfb_switch(int con, struct fb_info *info)
-{
-	currcon = con;
-	acornfb_update_var(con, info);
 	return 0;
 }
 
 static void
 acornfb_blank(int blank, struct fb_info *info)
 {
+	int i;
+
+	if (blank)
+		for (i = 0; i < current_par.palette_size; i++) {
+			union palette p;
+
+			p = acornfb_palette_encode(i, 0, 0, 0, 0);
+
+			acornfb_palette_write(i, p);
+		}
+	else
+		for (i = 0; i < current_par.palette_size; i++)
+			acornfb_palette_write(i, current_par.palette[i]);
+}
+
+/*
+ * Everything after here is initialisation!!!
+ */
+struct modey_params {
+	u_int	y_res;
+	u_int	u_margin;
+	u_int	b_margin;
+	u_int	vsync_len;
+	u_int	vf;
+};
+
+struct modex_params {
+	u_int	x_res;
+	u_int	l_margin;
+	u_int	r_margin;
+	u_int	hsync_len;
+	u_int	clock;
+	u_int	hf;
+	const struct modey_params *modey;
+};
+
+static const struct modey_params modey_640_15600[] __initdata = {
+	{  250,  38,  21,  3,  50 },	/*  640x 250, 50Hz */
+	{  256,  35,  18,  3,  50 },	/*  640x 256, 50Hz */
+	{    0,   0,   0,  0,   0 }
+};
+
+static const struct modey_params modey_640_26800[] __initdata = {
+	{  512,  18,   1,  3,  50 },	/*  640x 512, 50Hz */
+	{    0,   0,   0,  0,   0 }
+};
+
+static const struct modey_params modey_640_31500[] __initdata = {
+	{  250, 109,  88,  2,  70 },	/*  640x 250, 70Hz */
+	{  256, 106,  85,  2,  70 },	/*  640x 256, 70Hz */
+	{  352,  58,  37,  2,  70 },	/*  640x 352, 70Hz */
+	{  480,  32,  11,  2,  60 },	/*  640x 480, 60Hz */
+	{    0,   0,   0,  0,   0 }
+};
+
+static const struct modey_params modey_800_35200[] __initdata = {
+	{  600,  22,   1,  2,  56 },	/*  800x 600, 56Hz */
+	{    0,   0,   0,  0,   0 }
+};
+
+static const struct modey_params modey_896_21800[] __initdata = {
+	{  352,   9,   0,  3,  60 },	/*  896x 352, 60Hz */
+	{    0,   0,   0,  0,   0 }
+};
+
+/* everything after here is not supported */
+static const struct modey_params modey_1024_uk[] __initdata = {
+	{  768,   0,   0,  0,   0 },	/* 1024x 768 */
+	{    0,   0,   0,  0,   0 }
+};
+
+static const struct modey_params modey_1056_uk[] __initdata = {
+	{  250,   0,   0,  0,   0 },	/* 1056x 250 */
+	{  256,   0,   0,  0,   0 },	/* 1056x 256 */
+	{    0,   0,   0,  0,   0 }
+};
+
+static const struct modey_params modey_1152_uk[] __initdata = {
+	{  896,   0,   0,  0,   0 },	/* 1152x 896 */
+	{    0,   0,   0,  0,   0 }
+};
+
+static const struct modey_params modey_1280_63600[] __initdata = {
+	{ 1024,   0,   0,  0,  60 },	/* 1280x1024, 60Hz */
+	{    0,   0,   0,  0,   0 }
+};
+
+static const struct modey_params modey_1600_uk[] __initdata = {
+	{ 1280,   0,   0,  0,   0 },	/* 1600x1280 */
+	{    0,   0,   0,  0,   0 }
+};
+
+/*
+ * Horizontal video programming requirements.
+ * This table is searched for the required horizontal
+ * and required frequency, and then the tables above
+ * are then searched for the required vertical
+ * resolution.
+ *
+ * NOTE! we can match multiple entries, so we search
+ * all horizontal entries for which the hfreq is within
+ * the monitor's range.
+ */
+static const struct modex_params modex_params[] __initdata = {
+	{						/* X:  640, 15.6kHz */
+		 640,  185, 123,  76, 16000, 15625, modey_640_15600
+	},
+	{						/* X:  640, 26.8kHz */
+		 640,  113,  87,  56, 24000, 26800, modey_640_26800
+	},
+	{						/* X:  640, 31.5kHz */
+		 640,   48,  16,  96, 25175, 31500, modey_640_31500
+	},
+	{						/* X:  800, 35.2kHz */
+		 800,  101,  23, 100, 36000, 35200, modey_800_35200
+	},
+	{						/* X:  896, 21.8kHz */
+		 896,   59,  27, 118, 24000, 21800, modey_896_21800
+	},
+	{						/* X: 1024 */
+		1024,    0,   0,   0,     0,     0, modey_1024_uk
+	},
+	{						/* X: 1056 */
+		1056,    0,   0,   0,     0,     0, modey_1056_uk
+	},
+	{						/* X: 1152 */
+		1152,    0,   0,   0,     0,     0, modey_1152_uk
+	},
+	{						/* X: 1280, 63.6kHz */
+		1280,    0,   0,   0,     0, 63600, modey_1280_63600
+	},
+	{						/* X: 1600 */
+		1600,    0,   0,   0,     0,     0, modey_1600_uk
+	},
+	{
+		0,
+	}
+};
+
+__initfunc(static int
+acornfb_lookup_timing(struct fb_var_screeninfo *var))
+{
+	const struct modex_params *x;
+	const struct modey_params *y;
+
+	/*
+	 * We must adjust the resolution parameters
+	 * before selecting the timing parameters.
+	 */
+	acornfb_pre_adjust_timing(var, -1);
+
+	for (x = modex_params; x->x_res; x++) {
+
+		/*
+		 * Is this resolution one we're looking for?
+		 */
+		if (x->x_res != var->xres)
+			continue;
+
+		/*
+		 * Is the hsync frequency ok for our monitor?
+		 */
+		if (x->hf > fb_info.monspecs.hfmax ||
+		    x->hf < fb_info.monspecs.hfmin)
+			continue;
+
+		/*
+		 * Try to find a vertical resolution
+		 */
+		for (y = x->modey; y->y_res; y++) {
+			/*
+			 * Is this resolution one we're looking for?
+			 */
+			if (y->y_res != var->yres)
+				continue;
+
+			/*
+			 * Is the vsync frequency ok for our monitor?
+			 */
+			if (y->vf > fb_info.monspecs.vfmax ||
+			    y->vf < fb_info.monspecs.vfmin)
+				continue;
+
+			goto found;
+		}
+	}
+
+	var->pixclock = 0;
+
+	return -EINVAL;
+
+found:
+	/*
+	 * Why is pixclock in picoseconds?
+	 */
+	switch (x->clock) {
+	case 36000: var->pixclock =  27778;	break;
+	case 25175: var->pixclock =  39722;	break;
+	case 24000: var->pixclock =  41667;	break;
+	case 16000: var->pixclock =  62500;	break;
+	case 12000: var->pixclock =  83333;	break;
+	case  8000: var->pixclock = 125000;	break;
+	default:    var->pixclock =      0;     break;
+	}
+
+#ifdef DEBUG_MODE_SELECTION
+	printk(KERN_DEBUG "Found %dx%d at %d.%3dkHz, %dHz, pix %d\n",
+		x->x_res, y->y_res,
+		x->hf / 1000, x->hf % 1000,
+		y->vf, var->pixclock);
+#endif
+
+	var->left_margin	= x->l_margin;
+	var->right_margin	= x->r_margin;
+	var->upper_margin	= y->u_margin;
+	var->lower_margin	= y->b_margin;
+	var->hsync_len		= x->hsync_len;
+	var->vsync_len		= y->vsync_len;
+	var->sync		= 0;
+
+	/*
+	 * Now adjust the parameters we found
+	 */
+	acornfb_post_adjust_timing(var);
+
+	return 0;
 }
 
-__initfunc(unsigned long
-acornfb_init(unsigned long mem_start))
+__initfunc(static void
+acornfb_init_fbinfo(void))
 {
+	static int first = 1;
+
+	if (!first)
+		return;
+	first = 0;
+
 	strcpy(fb_info.modename, "Acorn");
-	fb_info.node		= -1;
-	fb_info.fbops		= &acornfb_ops;
-	fb_info.disp		= &disp;
-	fb_info.monspecs.hfmin	= 0;
-	fb_info.monspecs.hfmax	= 0;
-	fb_info.monspecs.vfmin	= 0;
-	fb_info.monspecs.vfmax	= 0;
-	fb_info.monspecs.dpms	= 0;
 	strcpy(fb_info.fontname, "Acorn8x8");
-	fb_info.changevar	= NULL;
-	fb_info.switch_con	= acornfb_switch;
-	fb_info.updatevar	= acornfb_update_var;
-	fb_info.blank		= acornfb_blank;
-	fb_info.flags		= FBINFO_FLAG_DEFAULT;
-
-	acornfb_set_disp(-1);
-	fb_set_cmap(fb_default_cmap(current_par.palette_size),
-		    1, acornfb_vidc20_setcolreg, &fb_info);
-	register_framebuffer(&fb_info);
 
-	return mem_start;
+	fb_info.node		   = -1;
+	fb_info.fbops		   = &acornfb_ops;
+	fb_info.disp		   = &global_disp;
+	fb_info.changevar	   = NULL;
+	fb_info.switch_con	   = acornfb_switch;
+	fb_info.updatevar	   = acornfb_updatevar;
+	fb_info.blank		   = acornfb_blank;
+	fb_info.flags		   = FBINFO_FLAG_DEFAULT;
+
+	global_disp.dispsw	   = &fbcon_dummy;
+
+	/*
+	 * setup initial parameters
+	 */
+	memset(&init_var, 0, sizeof(init_var));
+	init_var.xres		   = DEFAULT_XRES;
+	init_var.yres		   = DEFAULT_YRES;
+
+#if   defined(FBCON_HAS_CFB4)
+	init_var.bits_per_pixel	   = 4;
+#elif defined(FBCON_HAS_CFB8)
+	init_var.bits_per_pixel    = 8;
+#elif defined(FBCON_HAS_CFB2)
+	init_var.bits_per_pixel    = 2;
+#elif defined(FBCON_HAS_MFB)
+	init_var.bits_per_pixel    = 1;
+#else
+#error No suitable framebuffers configured
+#endif
+
+#if defined(HAS_VIDC20)
+	init_var.red.length	   = 8;
+	init_var.transp.length	   = 4;
+#elif defined(HAS_VIDC)
+	init_var.red.length	   = 4;
+	init_var.transp.length	   = 1;
+#endif
+	init_var.green		   = init_var.red;
+	init_var.blue		   = init_var.red;
+	init_var.nonstd		   = 0;
+	init_var.activate	   = FB_ACTIVATE_NOW;
+	init_var.height		   = -1;
+	init_var.width		   = -1;
+	init_var.vmode		   = FB_VMODE_NONINTERLACED;
+
+	current_par.dram_size	   = 0;
+	current_par.montype	   = -1;
+	current_par.dpms	   = 0;
+}
+
+/*
+ * setup acornfb options:
+ *
+ *  font:fontname
+ *	Set fontname
+ *
+ *  mon:hmin-hmax:vmin-vmax:dpms:width:height
+ *	Set monitor parameters:
+ *		hmin   = horizontal minimum frequency (Hz)
+ *		hmax   = horizontal maximum frequency (Hz)	(optional)
+ *		vmin   = vertical minimum frequency (Hz)
+ *		vmax   = vertical maximum frequency (Hz)	(optional)
+ *		dpms   = DPMS supported?			(optional)
+ *		width  = width of picture in mm.		(optional)
+ *		height = height of picture in mm.		(optional)
+ *
+ * montype:type
+ *	Set RISC-OS style monitor type:
+ *		0 (or tv)	- TV frequency
+ *		1 (or multi)	- Multi frequency
+ *		2 (or hires)	- Hi-res monochrome
+ *		3 (or vga)	- VGA
+ *		4 (or svga)	- SVGA
+ *		auto, or option missing
+ *				- try hardware detect
+ *
+ * dram:size
+ *	Set the amount of DRAM to use for the frame buffer
+ *	(even if you have VRAM).
+ *	size can optionally be followed by 'M' or 'K' for
+ *	MB or KB respectively.
+ */
+__initfunc(static void
+acornfb_parse_font(char *opt))
+{
+	strcpy(fb_info.fontname, opt);
+}
+
+__initfunc(static void
+acornfb_parse_mon(char *opt))
+{
+	fb_info.monspecs.hfmin = simple_strtoul(opt, &opt, 0);
+	if (*opt == '-')
+		fb_info.monspecs.hfmax = simple_strtoul(opt + 1, &opt, 0);
+	else
+		fb_info.monspecs.hfmax = fb_info.monspecs.hfmin;
+
+	if (*opt != ':')
+		return;
+
+	fb_info.monspecs.vfmin = simple_strtoul(opt + 1, &opt, 0);
+	if (*opt == '-')
+		fb_info.monspecs.vfmax = simple_strtoul(opt + 1, &opt, 0);
+	else
+		fb_info.monspecs.vfmax = fb_info.monspecs.vfmin;
+
+	if (*opt != ':')
+		return;
+
+	fb_info.monspecs.dpms = simple_strtoul(opt + 1, &opt, 0);
+
+	if (*opt != ':')
+		return;
+
+	init_var.width = simple_strtoul(opt + 1, &opt, 0);
+
+	if (*opt != ':')
+		return;
+
+	init_var.height = simple_strtoul(opt + 1, NULL, 0);
+}
+
+__initfunc(static void
+acornfb_parse_montype(char *opt))
+{
+	current_par.montype = -2;
+
+	if (strncmp(opt, "tv", 2) == 0) {
+		opt += 2;
+		current_par.montype = 0;
+	} else if (strncmp(opt, "multi", 5) == 0) {
+		opt += 5;
+		current_par.montype = 1;
+	} else if (strncmp(opt, "hires", 5) == 0) {
+		opt += 5;
+		current_par.montype = 2;
+	} else if (strncmp(opt, "vga", 3) == 0) {
+		opt += 3;
+		current_par.montype = 3;
+	} else if (strncmp(opt, "svga", 4) == 0) {
+		opt += 4;
+		current_par.montype = 4;
+	} else if (strncmp(opt, "auto", 4) == 0) {
+		opt += 4;
+		current_par.montype = -1;
+	} else if (isdigit(*opt))
+		current_par.montype = simple_strtoul(opt, &opt, 0);
+
+	if (current_par.montype == -2 ||
+	    current_par.montype > NR_MONTYPES) {
+		printk(KERN_ERR "acornfb: unknown monitor type: %s\n",
+			opt);
+		current_par.montype = -1;
+	} else
+	if (opt && *opt) {
+		if (strcmp(opt, ",dpms") == 0)
+			current_par.dpms = 1;
+		else
+			printk(KERN_ERR
+			       "acornfb: unknown monitor option: %s\n",
+			       opt);
+	}
+}
+
+__initfunc(static void
+acornfb_parse_dram(char *opt))
+{
+	unsigned int size;
+
+	size = simple_strtoul(opt, &opt, 0);
+
+	if (opt) {
+		switch (*opt) {
+		case 'M':
+		case 'm':
+			size *= 1024;
+		case 'K':
+		case 'k':
+			size *= 1024;
+		default:
+			break;
+		}
+	}
+
+	current_par.dram_size = size;
+}
+
+static struct options {
+	char *name;
+	void (*parse)(char *opt);
+} opt_table[] __initdata = {
+	{ "font",    acornfb_parse_font    },
+	{ "mon",     acornfb_parse_mon     },
+	{ "montype", acornfb_parse_montype },
+	{ "dram",    acornfb_parse_dram    },
+	{ NULL, NULL }
+};
+
+__initfunc(void
+acornfb_setup(char *options, int *ints))
+{
+	struct options *optp;
+	char *opt;
+
+	if (!options || !*options)
+		return;
+
+	acornfb_init_fbinfo();
+
+	for (opt = strtok(options, ","); opt; opt = strtok(NULL, ",")) {
+		if (!*opt)
+			continue;
+
+		for (optp = opt_table; optp->name; optp++) {
+			int optlen;
+
+			optlen = strlen(optp->name);
+
+			if (strncmp(opt, optp->name, optlen) == 0 &&
+			    opt[optlen] == ':') {
+				optp->parse(opt + optlen + 1);
+				break;
+			}
+		}
+
+		if (!optp->name)
+			printk(KERN_ERR "acornfb: unknown parameter: %s\n",
+			       opt);
+	}
+}
+
+/*
+ * Detect type of monitor connected
+ *  For now, we just assume SVGA
+ */
+__initfunc(static int
+acornfb_detect_monitortype(void))
+{
+	return 4;
+}
+
+/*
+ * This enables the unused memory to be freed on older Acorn machines.
+ */
+static inline void
+free_unused_pages(unsigned int virtual_start, unsigned int virtual_end)
+{
+	int mb_freed = 0;
+
+	/*
+	 * Align addresses
+	 */
+	virtual_start = PAGE_ALIGN(virtual_start);
+	virtual_end = PAGE_ALIGN(virtual_end);
+
+	while (virtual_start < virtual_end) {
+		/*
+		 * Clear page reserved bit,
+		 * set count to 1, and free
+		 * the page.
+		 */
+		clear_bit(PG_reserved, &mem_map[MAP_NR(virtual_start)].flags);
+		atomic_set(&mem_map[MAP_NR(virtual_start)].count, 1);
+		free_page(virtual_start);
+
+		virtual_start += PAGE_SIZE;
+		mb_freed += PAGE_SIZE / 1024;
+	}
+
+	printk("acornfb: freed %dK memory\n", mb_freed);
+}
+
+__initfunc(void
+acornfb_init(void))
+{
+	unsigned long size;
+	u_int h_sync, v_sync;
+
+	acornfb_init_fbinfo();
+
+	if (current_par.montype == -1)
+		current_par.montype = acornfb_detect_monitortype();
+
+	if (current_par.montype < 0 || current_par.montype > NR_MONTYPES)
+		current_par.montype = 4;
+
+	fb_info.monspecs = monspecs[current_par.montype];
+	fb_info.monspecs.dpms = current_par.dpms;
+
+	current_par.currcon	   = -1;
+	current_par.screen_base	   = SCREEN2_BASE;
+	current_par.screen_base_p  = SCREEN_START;
+	current_par.using_vram     = 0;
+
+	/*
+	 * If vram_size is set, we are using VRAM in
+	 * a Risc PC.  However, if the user has specified
+	 * an amount of DRAM then use that instead.
+	 */
+	if (vram_size && !current_par.dram_size) {
+		size = vram_size;
+		current_par.vram_half_sam = vram_size / 1024;
+		current_par.using_vram = 1;
+	} else if (current_par.dram_size)
+		size = current_par.dram_size;
+	else
+		size = (init_var.xres * init_var.yres *
+			init_var.bits_per_pixel) / 8;
+
+	size = PAGE_ALIGN(size);
+
+#ifdef CONFIG_ARCH_RPC
+	if (!current_par.using_vram) {
+		/*
+		 * RiscPC needs to allocate the DRAM memory
+		 * for the framebuffer if we are not using
+		 * VRAM.  Archimedes/A5000 machines use a
+		 * fixed address for their framebuffers.
+		 */
+		current_par.screen_base = (unsigned long)kmalloc(size, GFP_KERNEL);
+		if (current_par.screen_base == 0) {
+			printk(KERN_ERR "acornfb: unable to allocate screen "
+			       "memory\n");
+			return;
+		}
+		current_par.screen_base_p =
+			virt_to_phys(current_par.screen_base);
+	}
+#endif
+#if defined(CONFIG_ARCH_A5K) || defined(CONFIG_ARCH_ARC)
+#define MAX_SIZE	480*1024
+	/*
+	 * Limit maximum screen size.
+	 */
+	if (size > MAX_SIZE)
+		size = MAX_SIZE;
+
+	/*
+	 * Free unused pages
+	 */
+	free_unused_pages(PAGE_OFFSET + size, PAGE_OFFSET + MAX_SIZE);
+#endif
+	
+	current_par.screen_size	   = size;
+	current_par.palette_size   = VIDC_PALETTE_SIZE;
+	current_par.allow_modeset  = 1;
+
+	/*
+	 * Lookup the timing for this resolution.  If we can't
+	 * find it, then we can't restore it if we change
+	 * the resolution, so we disable this feature.
+	 */
+	if (acornfb_lookup_timing(&init_var))
+		current_par.allow_modeset = 0;
+
+	/*
+	 * Again, if this does not succeed, then we disallow
+	 * changes to the resolution parameters.
+	 */
+	if (acornfb_set_var(&init_var, -1, &fb_info))
+		current_par.allow_modeset = 0;
+
+	h_sync = 1953125000 / init_var.pixclock;
+	h_sync = h_sync * 512 / (init_var.xres + init_var.left_margin +
+		 init_var.right_margin + init_var.hsync_len);
+	v_sync = h_sync / (init_var.yres + init_var.upper_margin +
+		 init_var.lower_margin + init_var.vsync_len);
+
+	printk("Acornfb: %ldkB %cRAM, %s, using %dx%d, %d.%03dkHz, %dHz\n",
+		current_par.screen_size / 1024,
+		current_par.using_vram ? 'V' : 'D',
+		VIDC_NAME, init_var.xres, init_var.yres,
+		h_sync / 1000, h_sync % 1000, v_sync);
+
+	register_framebuffer(&fb_info);
 }

FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)