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/arkfb.c | 1218 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 1218 insertions(+)
 create mode 100644 drivers/video/fbdev/arkfb.c

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

diff --git a/drivers/video/fbdev/arkfb.c b/drivers/video/fbdev/arkfb.c
new file mode 100644
index 000000000..866c11657
--- /dev/null
+++ b/drivers/video/fbdev/arkfb.c
@@ -0,0 +1,1218 @@
+/*
+ *  linux/drivers/video/arkfb.c -- Frame buffer device driver for ARK 2000PV
+ *  with ICS 5342 dac (it is easy to add support for different dacs).
+ *
+ *  Copyright (c) 2007 Ondrej Zajicek <santiago@crfreenet.org>
+ *
+ *  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.
+ *
+ *  Code is based on s3fb
+ */
+
+#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/tty.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/fb.h>
+#include <linux/svga.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/console.h> /* Why should fb driver call console functions? because console_lock() */
+#include <video/vga.h>
+
+struct arkfb_info {
+	int mclk_freq;
+	int wc_cookie;
+
+	struct dac_info *dac;
+	struct vgastate state;
+	struct mutex open_lock;
+	unsigned int ref_count;
+	u32 pseudo_palette[16];
+};
+
+
+/* ------------------------------------------------------------------------- */
+
+
+static const struct svga_fb_format arkfb_formats[] = {
+	{ 0,  {0, 6, 0},  {0, 6, 0},  {0, 6, 0}, {0, 0, 0}, 0,
+		FB_TYPE_TEXT, FB_AUX_TEXT_SVGA_STEP4,	FB_VISUAL_PSEUDOCOLOR, 8, 8},
+	{ 4,  {0, 6, 0},  {0, 6, 0},  {0, 6, 0}, {0, 0, 0}, 0,
+		FB_TYPE_PACKED_PIXELS, 0,		FB_VISUAL_PSEUDOCOLOR, 8, 16},
+	{ 4,  {0, 6, 0},  {0, 6, 0},  {0, 6, 0}, {0, 0, 0}, 1,
+		FB_TYPE_INTERLEAVED_PLANES, 1,		FB_VISUAL_PSEUDOCOLOR, 8, 16},
+	{ 8,  {0, 6, 0},  {0, 6, 0},  {0, 6, 0}, {0, 0, 0}, 0,
+		FB_TYPE_PACKED_PIXELS, 0,		FB_VISUAL_PSEUDOCOLOR, 8, 8},
+	{16,  {10, 5, 0}, {5, 5, 0},  {0, 5, 0}, {0, 0, 0}, 0,
+		FB_TYPE_PACKED_PIXELS, 0,		FB_VISUAL_TRUECOLOR, 4, 4},
+	{16,  {11, 5, 0}, {5, 6, 0},  {0, 5, 0}, {0, 0, 0}, 0,
+		FB_TYPE_PACKED_PIXELS, 0,		FB_VISUAL_TRUECOLOR, 4, 4},
+	{24,  {16, 8, 0}, {8, 8, 0},  {0, 8, 0}, {0, 0, 0}, 0,
+		FB_TYPE_PACKED_PIXELS, 0,		FB_VISUAL_TRUECOLOR, 8, 8},
+	{32,  {16, 8, 0}, {8, 8, 0},  {0, 8, 0}, {0, 0, 0}, 0,
+		FB_TYPE_PACKED_PIXELS, 0,		FB_VISUAL_TRUECOLOR, 2, 2},
+	SVGA_FORMAT_END
+};
+
+
+/* CRT timing register sets */
+
+static const struct vga_regset ark_h_total_regs[]        = {{0x00, 0, 7}, {0x41, 7, 7}, VGA_REGSET_END};
+static const struct vga_regset ark_h_display_regs[]      = {{0x01, 0, 7}, {0x41, 6, 6}, VGA_REGSET_END};
+static const struct vga_regset ark_h_blank_start_regs[]  = {{0x02, 0, 7}, {0x41, 5, 5}, VGA_REGSET_END};
+static const struct vga_regset ark_h_blank_end_regs[]    = {{0x03, 0, 4}, {0x05, 7, 7	}, VGA_REGSET_END};
+static const struct vga_regset ark_h_sync_start_regs[]   = {{0x04, 0, 7}, {0x41, 4, 4}, VGA_REGSET_END};
+static const struct vga_regset ark_h_sync_end_regs[]     = {{0x05, 0, 4}, VGA_REGSET_END};
+
+static const struct vga_regset ark_v_total_regs[]        = {{0x06, 0, 7}, {0x07, 0, 0}, {0x07, 5, 5}, {0x40, 7, 7}, VGA_REGSET_END};
+static const struct vga_regset ark_v_display_regs[]      = {{0x12, 0, 7}, {0x07, 1, 1}, {0x07, 6, 6}, {0x40, 6, 6}, VGA_REGSET_END};
+static const struct vga_regset ark_v_blank_start_regs[]  = {{0x15, 0, 7}, {0x07, 3, 3}, {0x09, 5, 5}, {0x40, 5, 5}, VGA_REGSET_END};
+// const struct vga_regset ark_v_blank_end_regs[]    = {{0x16, 0, 6}, VGA_REGSET_END};
+static const struct vga_regset ark_v_blank_end_regs[]    = {{0x16, 0, 7}, VGA_REGSET_END};
+static const struct vga_regset ark_v_sync_start_regs[]   = {{0x10, 0, 7}, {0x07, 2, 2}, {0x07, 7, 7}, {0x40, 4, 4}, VGA_REGSET_END};
+static const struct vga_regset ark_v_sync_end_regs[]     = {{0x11, 0, 3}, VGA_REGSET_END};
+
+static const struct vga_regset ark_line_compare_regs[]   = {{0x18, 0, 7}, {0x07, 4, 4}, {0x09, 6, 6}, VGA_REGSET_END};
+static const struct vga_regset ark_start_address_regs[]  = {{0x0d, 0, 7}, {0x0c, 0, 7}, {0x40, 0, 2}, VGA_REGSET_END};
+static const struct vga_regset ark_offset_regs[]         = {{0x13, 0, 7}, {0x41, 3, 3}, VGA_REGSET_END};
+
+static const struct svga_timing_regs ark_timing_regs     = {
+	ark_h_total_regs, ark_h_display_regs, ark_h_blank_start_regs,
+	ark_h_blank_end_regs, ark_h_sync_start_regs, ark_h_sync_end_regs,
+	ark_v_total_regs, ark_v_display_regs, ark_v_blank_start_regs,
+	ark_v_blank_end_regs, ark_v_sync_start_regs, ark_v_sync_end_regs,
+};
+
+
+/* ------------------------------------------------------------------------- */
+
+
+/* Module parameters */
+
+static char *mode_option = "640x480-8@60";
+
+MODULE_AUTHOR("(c) 2007 Ondrej Zajicek <santiago@crfreenet.org>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("fbdev driver for ARK 2000PV");
+
+module_param(mode_option, charp, 0444);
+MODULE_PARM_DESC(mode_option, "Default video mode ('640x480-8@60', etc)");
+module_param_named(mode, mode_option, charp, 0444);
+MODULE_PARM_DESC(mode, "Default video mode ('640x480-8@60', etc) (deprecated)");
+
+static int threshold = 4;
+
+module_param(threshold, int, 0644);
+MODULE_PARM_DESC(threshold, "FIFO threshold");
+
+
+/* ------------------------------------------------------------------------- */
+
+
+static void arkfb_settile(struct fb_info *info, struct fb_tilemap *map)
+{
+	const u8 *font = map->data;
+	u8 __iomem *fb = (u8 __iomem *)info->screen_base;
+	int i, c;
+
+	if ((map->width != 8) || (map->height != 16) ||
+	    (map->depth != 1) || (map->length != 256)) {
+		fb_err(info, "unsupported font parameters: width %d, height %d, depth %d, length %d\n",
+		       map->width, map->height, map->depth, map->length);
+		return;
+	}
+
+	fb += 2;
+	for (c = 0; c < map->length; c++) {
+		for (i = 0; i < map->height; i++) {
+			fb_writeb(font[i], &fb[i * 4]);
+			fb_writeb(font[i], &fb[i * 4 + (128 * 8)]);
+		}
+		fb += 128;
+
+		if ((c % 8) == 7)
+			fb += 128*8;
+
+		font += map->height;
+	}
+}
+
+static void arkfb_tilecursor(struct fb_info *info, struct fb_tilecursor *cursor)
+{
+	struct arkfb_info *par = info->par;
+
+	svga_tilecursor(par->state.vgabase, info, cursor);
+}
+
+static struct fb_tile_ops arkfb_tile_ops = {
+	.fb_settile	= arkfb_settile,
+	.fb_tilecopy	= svga_tilecopy,
+	.fb_tilefill    = svga_tilefill,
+	.fb_tileblit    = svga_tileblit,
+	.fb_tilecursor  = arkfb_tilecursor,
+	.fb_get_tilemax = svga_get_tilemax,
+};
+
+
+/* ------------------------------------------------------------------------- */
+
+
+/* image data is MSB-first, fb structure is MSB-first too */
+static inline u32 expand_color(u32 c)
+{
+	return ((c & 1) | ((c & 2) << 7) | ((c & 4) << 14) | ((c & 8) << 21)) * 0xFF;
+}
+
+/* arkfb_iplan_imageblit silently assumes that almost everything is 8-pixel aligned */
+static void arkfb_iplan_imageblit(struct fb_info *info, const struct fb_image *image)
+{
+	u32 fg = expand_color(image->fg_color);
+	u32 bg = expand_color(image->bg_color);
+	const u8 *src1, *src;
+	u8 __iomem *dst1;
+	u32 __iomem *dst;
+	u32 val;
+	int x, y;
+
+	src1 = image->data;
+	dst1 = info->screen_base + (image->dy * info->fix.line_length)
+		 + ((image->dx / 8) * 4);
+
+	for (y = 0; y < image->height; y++) {
+		src = src1;
+		dst = (u32 __iomem *) dst1;
+		for (x = 0; x < image->width; x += 8) {
+			val = *(src++) * 0x01010101;
+			val = (val & fg) | (~val & bg);
+			fb_writel(val, dst++);
+		}
+		src1 += image->width / 8;
+		dst1 += info->fix.line_length;
+	}
+
+}
+
+/* arkfb_iplan_fillrect silently assumes that almost everything is 8-pixel aligned */
+static void arkfb_iplan_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
+{
+	u32 fg = expand_color(rect->color);
+	u8 __iomem *dst1;
+	u32 __iomem *dst;
+	int x, y;
+
+	dst1 = info->screen_base + (rect->dy * info->fix.line_length)
+		 + ((rect->dx / 8) * 4);
+
+	for (y = 0; y < rect->height; y++) {
+		dst = (u32 __iomem *) dst1;
+		for (x = 0; x < rect->width; x += 8) {
+			fb_writel(fg, dst++);
+		}
+		dst1 += info->fix.line_length;
+	}
+
+}
+
+
+/* image data is MSB-first, fb structure is high-nibble-in-low-byte-first */
+static inline u32 expand_pixel(u32 c)
+{
+	return (((c &  1) << 24) | ((c &  2) << 27) | ((c &  4) << 14) | ((c &   8) << 17) |
+		((c & 16) <<  4) | ((c & 32) <<  7) | ((c & 64) >>  6) | ((c & 128) >>  3)) * 0xF;
+}
+
+/* arkfb_cfb4_imageblit silently assumes that almost everything is 8-pixel aligned */
+static void arkfb_cfb4_imageblit(struct fb_info *info, const struct fb_image *image)
+{
+	u32 fg = image->fg_color * 0x11111111;
+	u32 bg = image->bg_color * 0x11111111;
+	const u8 *src1, *src;
+	u8 __iomem *dst1;
+	u32 __iomem *dst;
+	u32 val;
+	int x, y;
+
+	src1 = image->data;
+	dst1 = info->screen_base + (image->dy * info->fix.line_length)
+		 + ((image->dx / 8) * 4);
+
+	for (y = 0; y < image->height; y++) {
+		src = src1;
+		dst = (u32 __iomem *) dst1;
+		for (x = 0; x < image->width; x += 8) {
+			val = expand_pixel(*(src++));
+			val = (val & fg) | (~val & bg);
+			fb_writel(val, dst++);
+		}
+		src1 += image->width / 8;
+		dst1 += info->fix.line_length;
+	}
+
+}
+
+static void arkfb_imageblit(struct fb_info *info, const struct fb_image *image)
+{
+	if ((info->var.bits_per_pixel == 4) && (image->depth == 1)
+	    && ((image->width % 8) == 0) && ((image->dx % 8) == 0)) {
+		if (info->fix.type == FB_TYPE_INTERLEAVED_PLANES)
+			arkfb_iplan_imageblit(info, image);
+		else
+			arkfb_cfb4_imageblit(info, image);
+	} else
+		cfb_imageblit(info, image);
+}
+
+static void arkfb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
+{
+	if ((info->var.bits_per_pixel == 4)
+	    && ((rect->width % 8) == 0) && ((rect->dx % 8) == 0)
+	    && (info->fix.type == FB_TYPE_INTERLEAVED_PLANES))
+		arkfb_iplan_fillrect(info, rect);
+	 else
+		cfb_fillrect(info, rect);
+}
+
+
+/* ------------------------------------------------------------------------- */
+
+
+enum
+{
+	DAC_PSEUDO8_8,
+	DAC_RGB1555_8,
+	DAC_RGB0565_8,
+	DAC_RGB0888_8,
+	DAC_RGB8888_8,
+	DAC_PSEUDO8_16,
+	DAC_RGB1555_16,
+	DAC_RGB0565_16,
+	DAC_RGB0888_16,
+	DAC_RGB8888_16,
+	DAC_MAX
+};
+
+struct dac_ops {
+	int (*dac_get_mode)(struct dac_info *info);
+	int (*dac_set_mode)(struct dac_info *info, int mode);
+	int (*dac_get_freq)(struct dac_info *info, int channel);
+	int (*dac_set_freq)(struct dac_info *info, int channel, u32 freq);
+	void (*dac_release)(struct dac_info *info);
+};
+
+typedef void (*dac_read_regs_t)(void *data, u8 *code, int count);
+typedef void (*dac_write_regs_t)(void *data, u8 *code, int count);
+
+struct dac_info
+{
+	struct dac_ops *dacops;
+	dac_read_regs_t dac_read_regs;
+	dac_write_regs_t dac_write_regs;
+	void *data;
+};
+
+static inline void dac_read_regs(struct dac_info *info, u8 *code, int count)
+{
+	info->dac_read_regs(info->data, code, count);
+}
+
+static inline void dac_write_reg(struct dac_info *info, u8 reg, u8 val)
+{
+	u8 code[2] = {reg, val};
+	info->dac_write_regs(info->data, code, 1);
+}
+
+static inline void dac_write_regs(struct dac_info *info, u8 *code, int count)
+{
+	info->dac_write_regs(info->data, code, count);
+}
+
+static inline int dac_set_mode(struct dac_info *info, int mode)
+{
+	return info->dacops->dac_set_mode(info, mode);
+}
+
+static inline int dac_set_freq(struct dac_info *info, int channel, u32 freq)
+{
+	return info->dacops->dac_set_freq(info, channel, freq);
+}
+
+static inline void dac_release(struct dac_info *info)
+{
+	info->dacops->dac_release(info);
+}
+
+
+/* ------------------------------------------------------------------------- */
+
+
+/* ICS5342 DAC */
+
+struct ics5342_info
+{
+	struct dac_info dac;
+	u8 mode;
+};
+
+#define DAC_PAR(info) ((struct ics5342_info *) info)
+
+/* LSB is set to distinguish unused slots */
+static const u8 ics5342_mode_table[DAC_MAX] = {
+	[DAC_PSEUDO8_8]  = 0x01, [DAC_RGB1555_8]  = 0x21, [DAC_RGB0565_8]  = 0x61,
+	[DAC_RGB0888_8]  = 0x41, [DAC_PSEUDO8_16] = 0x11, [DAC_RGB1555_16] = 0x31,
+	[DAC_RGB0565_16] = 0x51, [DAC_RGB0888_16] = 0x91, [DAC_RGB8888_16] = 0x71
+};
+
+static int ics5342_set_mode(struct dac_info *info, int mode)
+{
+	u8 code;
+
+	if (mode >= DAC_MAX)
+		return -EINVAL;
+
+	code = ics5342_mode_table[mode];
+
+	if (! code)
+		return -EINVAL;
+
+	dac_write_reg(info, 6, code & 0xF0);
+	DAC_PAR(info)->mode = mode;
+
+	return 0;
+}
+
+static const struct svga_pll ics5342_pll = {3, 129, 3, 33, 0, 3,
+	60000, 250000, 14318};
+
+/* pd4 - allow only posdivider 4 (r=2) */
+static const struct svga_pll ics5342_pll_pd4 = {3, 129, 3, 33, 2, 2,
+	60000, 335000, 14318};
+
+/* 270 MHz should be upper bound for VCO clock according to specs,
+   but that is too restrictive in pd4 case */
+
+static int ics5342_set_freq(struct dac_info *info, int channel, u32 freq)
+{
+	u16 m, n, r;
+
+	/* only postdivider 4 (r=2) is valid in mode DAC_PSEUDO8_16 */
+	int rv = svga_compute_pll((DAC_PAR(info)->mode == DAC_PSEUDO8_16)
+				  ? &ics5342_pll_pd4 : &ics5342_pll,
+				  freq, &m, &n, &r, 0);
+
+	if (rv < 0) {
+		return -EINVAL;
+	} else {
+		u8 code[6] = {4, 3, 5, m-2, 5, (n-2) | (r << 5)};
+		dac_write_regs(info, code, 3);
+		return 0;
+	}
+}
+
+static void ics5342_release(struct dac_info *info)
+{
+	ics5342_set_mode(info, DAC_PSEUDO8_8);
+	kfree(info);
+}
+
+static struct dac_ops ics5342_ops = {
+	.dac_set_mode	= ics5342_set_mode,
+	.dac_set_freq	= ics5342_set_freq,
+	.dac_release	= ics5342_release
+};
+
+
+static struct dac_info * ics5342_init(dac_read_regs_t drr, dac_write_regs_t dwr, void *data)
+{
+	struct ics5342_info *ics_info = kzalloc_obj(struct ics5342_info);
+	struct dac_info *info = &ics_info->dac;
+
+	if (!ics_info)
+		return NULL;
+
+	info->dacops = &ics5342_ops;
+	info->dac_read_regs = drr;
+	info->dac_write_regs = dwr;
+	info->data = data;
+	DAC_PAR(info)->mode = DAC_PSEUDO8_8; /* estimation */
+	return info;
+}
+
+
+/* ------------------------------------------------------------------------- */
+
+
+static unsigned short dac_regs[4] = {0x3c8, 0x3c9, 0x3c6, 0x3c7};
+
+static void ark_dac_read_regs(void *data, u8 *code, int count)
+{
+	struct fb_info *info = data;
+	struct arkfb_info *par;
+	u8 regval;
+
+	par = info->par;
+	regval = vga_rseq(par->state.vgabase, 0x1C);
+	while (count != 0)
+	{
+		vga_wseq(par->state.vgabase, 0x1C, regval | (code[0] & 4 ? 0x80 : 0));
+		code[1] = vga_r(par->state.vgabase, dac_regs[code[0] & 3]);
+		count--;
+		code += 2;
+	}
+
+	vga_wseq(par->state.vgabase, 0x1C, regval);
+}
+
+static void ark_dac_write_regs(void *data, u8 *code, int count)
+{
+	struct fb_info *info = data;
+	struct arkfb_info *par;
+	u8 regval;
+
+	par = info->par;
+	regval = vga_rseq(par->state.vgabase, 0x1C);
+	while (count != 0)
+	{
+		vga_wseq(par->state.vgabase, 0x1C, regval | (code[0] & 4 ? 0x80 : 0));
+		vga_w(par->state.vgabase, dac_regs[code[0] & 3], code[1]);
+		count--;
+		code += 2;
+	}
+
+	vga_wseq(par->state.vgabase, 0x1C, regval);
+}
+
+
+static void ark_set_pixclock(struct fb_info *info, u32 pixclock)
+{
+	struct arkfb_info *par = info->par;
+	u8 regval;
+
+	int rv = dac_set_freq(par->dac, 0, 1000000000 / pixclock);
+	if (rv < 0) {
+		fb_err(info, "cannot set requested pixclock, keeping old value\n");
+		return;
+	}
+
+	/* Set VGA misc register  */
+	regval = vga_r(par->state.vgabase, VGA_MIS_R);
+	vga_w(par->state.vgabase, VGA_MIS_W, regval | VGA_MIS_ENB_PLL_LOAD);
+}
+
+
+/* Open framebuffer */
+
+static int arkfb_open(struct fb_info *info, int user)
+{
+	struct arkfb_info *par = info->par;
+
+	mutex_lock(&(par->open_lock));
+	if (par->ref_count == 0) {
+		void __iomem *vgabase = par->state.vgabase;
+
+		memset(&(par->state), 0, sizeof(struct vgastate));
+		par->state.vgabase = vgabase;
+		par->state.flags = VGA_SAVE_MODE | VGA_SAVE_FONTS | VGA_SAVE_CMAP;
+		par->state.num_crtc = 0x60;
+		par->state.num_seq = 0x30;
+		save_vga(&(par->state));
+	}
+
+	par->ref_count++;
+	mutex_unlock(&(par->open_lock));
+
+	return 0;
+}
+
+/* Close framebuffer */
+
+static int arkfb_release(struct fb_info *info, int user)
+{
+	struct arkfb_info *par = info->par;
+
+	mutex_lock(&(par->open_lock));
+	if (par->ref_count == 0) {
+		mutex_unlock(&(par->open_lock));
+		return -EINVAL;
+	}
+
+	if (par->ref_count == 1) {
+		restore_vga(&(par->state));
+		dac_set_mode(par->dac, DAC_PSEUDO8_8);
+	}
+
+	par->ref_count--;
+	mutex_unlock(&(par->open_lock));
+
+	return 0;
+}
+
+/* Validate passed in var */
+
+static int arkfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
+{
+	int rv, mem, step;
+
+	if (!var->pixclock)
+		return -EINVAL;
+
+	/* Find appropriate format */
+	rv = svga_match_format (arkfb_formats, var, NULL);
+	if (rv < 0)
+	{
+		fb_err(info, "unsupported mode requested\n");
+		return rv;
+	}
+
+	/* Do not allow to have real resoulution larger than virtual */
+	if (var->xres > var->xres_virtual)
+		var->xres_virtual = var->xres;
+
+	if (var->yres > var->yres_virtual)
+		var->yres_virtual = var->yres;
+
+	/* Round up xres_virtual to have proper alignment of lines */
+	step = arkfb_formats[rv].xresstep - 1;
+	var->xres_virtual = (var->xres_virtual+step) & ~step;
+
+
+	/* Check whether have enough memory */
+	mem = ((var->bits_per_pixel * var->xres_virtual) >> 3) * var->yres_virtual;
+	if (mem > info->screen_size)
+	{
+		fb_err(info, "not enough framebuffer memory (%d kB requested, %d kB available)\n",
+		       mem >> 10, (unsigned int) (info->screen_size >> 10));
+		return -EINVAL;
+	}
+
+	rv = svga_check_timings (&ark_timing_regs, var, info->node);
+	if (rv < 0)
+	{
+		fb_err(info, "invalid timings requested\n");
+		return rv;
+	}
+
+	/* Interlaced mode is broken */
+	if (var->vmode & FB_VMODE_INTERLACED)
+		return -EINVAL;
+
+	return 0;
+}
+
+/* Set video mode from par */
+
+static int arkfb_set_par(struct fb_info *info)
+{
+	struct arkfb_info *par = info->par;
+	u32 value, mode, hmul, hdiv, offset_value, screen_size;
+	u32 bpp = info->var.bits_per_pixel;
+	u8 regval;
+
+	if (bpp != 0) {
+		info->fix.ypanstep = 1;
+		info->fix.line_length = (info->var.xres_virtual * bpp) / 8;
+
+		info->flags &= ~FBINFO_MISC_TILEBLITTING;
+		info->tileops = NULL;
+
+		/* in 4bpp supports 8p wide tiles only, any tiles otherwise */
+		if (bpp == 4) {
+			bitmap_zero(info->pixmap.blit_x, FB_MAX_BLIT_WIDTH);
+			set_bit(8 - 1, info->pixmap.blit_x);
+		} else {
+			bitmap_fill(info->pixmap.blit_x, FB_MAX_BLIT_WIDTH);
+		}
+		bitmap_fill(info->pixmap.blit_y, FB_MAX_BLIT_HEIGHT);
+
+		offset_value = (info->var.xres_virtual * bpp) / 64;
+		screen_size = info->var.yres_virtual * info->fix.line_length;
+	} else {
+		info->fix.ypanstep = 16;
+		info->fix.line_length = 0;
+
+		info->flags |= FBINFO_MISC_TILEBLITTING;
+		info->tileops = &arkfb_tile_ops;
+
+		/* supports 8x16 tiles only */
+		bitmap_zero(info->pixmap.blit_x, FB_MAX_BLIT_WIDTH);
+		set_bit(8 - 1, info->pixmap.blit_x);
+		bitmap_zero(info->pixmap.blit_y, FB_MAX_BLIT_HEIGHT);
+		set_bit(16 - 1, info->pixmap.blit_y);
+
+		offset_value = info->var.xres_virtual / 16;
+		screen_size = (info->var.xres_virtual * info->var.yres_virtual) / 64;
+	}
+
+	info->var.xoffset = 0;
+	info->var.yoffset = 0;
+	info->var.activate = FB_ACTIVATE_NOW;
+
+	/* Unlock registers */
+	svga_wcrt_mask(par->state.vgabase, 0x11, 0x00, 0x80);
+
+	/* Blank screen and turn off sync */
+	svga_wseq_mask(par->state.vgabase, 0x01, 0x20, 0x20);
+	svga_wcrt_mask(par->state.vgabase, 0x17, 0x00, 0x80);
+
+	/* Set default values */
+	svga_set_default_gfx_regs(par->state.vgabase);
+	svga_set_default_atc_regs(par->state.vgabase);
+	svga_set_default_seq_regs(par->state.vgabase);
+	svga_set_default_crt_regs(par->state.vgabase);
+	svga_wcrt_multi(par->state.vgabase, ark_line_compare_regs, 0xFFFFFFFF);
+	svga_wcrt_multi(par->state.vgabase, ark_start_address_regs, 0);
+
+	/* ARK specific initialization */
+	svga_wseq_mask(par->state.vgabase, 0x10, 0x1F, 0x1F); /* enable linear framebuffer and full memory access */
+	svga_wseq_mask(par->state.vgabase, 0x12, 0x03, 0x03); /* 4 MB linear framebuffer size */
+
+	vga_wseq(par->state.vgabase, 0x13, info->fix.smem_start >> 16);
+	vga_wseq(par->state.vgabase, 0x14, info->fix.smem_start >> 24);
+	vga_wseq(par->state.vgabase, 0x15, 0);
+	vga_wseq(par->state.vgabase, 0x16, 0);
+
+	/* Set the FIFO threshold register */
+	/* It is fascinating way to store 5-bit value in 8-bit register */
+	regval = 0x10 | ((threshold & 0x0E) >> 1) | (threshold & 0x01) << 7 | (threshold & 0x10) << 1;
+	vga_wseq(par->state.vgabase, 0x18, regval);
+
+	/* Set the offset register */
+	fb_dbg(info, "offset register       : %d\n", offset_value);
+	svga_wcrt_multi(par->state.vgabase, ark_offset_regs, offset_value);
+
+	/* fix for hi-res textmode */
+	svga_wcrt_mask(par->state.vgabase, 0x40, 0x08, 0x08);
+
+	if (info->var.vmode & FB_VMODE_DOUBLE)
+		svga_wcrt_mask(par->state.vgabase, 0x09, 0x80, 0x80);
+	else
+		svga_wcrt_mask(par->state.vgabase, 0x09, 0x00, 0x80);
+
+	if (info->var.vmode & FB_VMODE_INTERLACED)
+		svga_wcrt_mask(par->state.vgabase, 0x44, 0x04, 0x04);
+	else
+		svga_wcrt_mask(par->state.vgabase, 0x44, 0x00, 0x04);
+
+	hmul = 1;
+	hdiv = 1;
+	mode = svga_match_format(arkfb_formats, &(info->var), &(info->fix));
+
+	/* Set mode-specific register values */
+	switch (mode) {
+	case 0:
+		fb_dbg(info, "text mode\n");
+		svga_set_textmode_vga_regs(par->state.vgabase);
+
+		vga_wseq(par->state.vgabase, 0x11, 0x10); /* basic VGA mode */
+		svga_wcrt_mask(par->state.vgabase, 0x46, 0x00, 0x04); /* 8bit pixel path */
+		dac_set_mode(par->dac, DAC_PSEUDO8_8);
+
+		break;
+	case 1:
+		fb_dbg(info, "4 bit pseudocolor\n");
+		vga_wgfx(par->state.vgabase, VGA_GFX_MODE, 0x40);
+
+		vga_wseq(par->state.vgabase, 0x11, 0x10); /* basic VGA mode */
+		svga_wcrt_mask(par->state.vgabase, 0x46, 0x00, 0x04); /* 8bit pixel path */
+		dac_set_mode(par->dac, DAC_PSEUDO8_8);
+		break;
+	case 2:
+		fb_dbg(info, "4 bit pseudocolor, planar\n");
+
+		vga_wseq(par->state.vgabase, 0x11, 0x10); /* basic VGA mode */
+		svga_wcrt_mask(par->state.vgabase, 0x46, 0x00, 0x04); /* 8bit pixel path */
+		dac_set_mode(par->dac, DAC_PSEUDO8_8);
+		break;
+	case 3:
+		fb_dbg(info, "8 bit pseudocolor\n");
+
+		vga_wseq(par->state.vgabase, 0x11, 0x16); /* 8bpp accel mode */
+
+		if (info->var.pixclock > 20000) {
+			fb_dbg(info, "not using multiplex\n");
+			svga_wcrt_mask(par->state.vgabase, 0x46, 0x00, 0x04); /* 8bit pixel path */
+			dac_set_mode(par->dac, DAC_PSEUDO8_8);
+		} else {
+			fb_dbg(info, "using multiplex\n");
+			svga_wcrt_mask(par->state.vgabase, 0x46, 0x04, 0x04); /* 16bit pixel path */
+			dac_set_mode(par->dac, DAC_PSEUDO8_16);
+			hdiv = 2;
+		}
+		break;
+	case 4:
+		fb_dbg(info, "5/5/5 truecolor\n");
+
+		vga_wseq(par->state.vgabase, 0x11, 0x1A); /* 16bpp accel mode */
+		svga_wcrt_mask(par->state.vgabase, 0x46, 0x04, 0x04); /* 16bit pixel path */
+		dac_set_mode(par->dac, DAC_RGB1555_16);
+		break;
+	case 5:
+		fb_dbg(info, "5/6/5 truecolor\n");
+
+		vga_wseq(par->state.vgabase, 0x11, 0x1A); /* 16bpp accel mode */
+		svga_wcrt_mask(par->state.vgabase, 0x46, 0x04, 0x04); /* 16bit pixel path */
+		dac_set_mode(par->dac, DAC_RGB0565_16);
+		break;
+	case 6:
+		fb_dbg(info, "8/8/8 truecolor\n");
+
+		vga_wseq(par->state.vgabase, 0x11, 0x16); /* 8bpp accel mode ??? */
+		svga_wcrt_mask(par->state.vgabase, 0x46, 0x04, 0x04); /* 16bit pixel path */
+		dac_set_mode(par->dac, DAC_RGB0888_16);
+		hmul = 3;
+		hdiv = 2;
+		break;
+	case 7:
+		fb_dbg(info, "8/8/8/8 truecolor\n");
+
+		vga_wseq(par->state.vgabase, 0x11, 0x1E); /* 32bpp accel mode */
+		svga_wcrt_mask(par->state.vgabase, 0x46, 0x04, 0x04); /* 16bit pixel path */
+		dac_set_mode(par->dac, DAC_RGB8888_16);
+		hmul = 2;
+		break;
+	default:
+		fb_err(info, "unsupported mode - bug\n");
+		return -EINVAL;
+	}
+
+	value = (hdiv * info->var.pixclock) / hmul;
+	if (!value) {
+		fb_dbg(info, "invalid pixclock\n");
+		value = 1;
+	}
+	ark_set_pixclock(info, value);
+	svga_set_timings(par->state.vgabase, &ark_timing_regs, &(info->var), hmul, hdiv,
+			 (info->var.vmode & FB_VMODE_DOUBLE)     ? 2 : 1,
+			 (info->var.vmode & FB_VMODE_INTERLACED) ? 2 : 1,
+			  hmul, info->node);
+
+	/* Set interlaced mode start/end register */
+	value = info->var.xres + info->var.left_margin + info->var.right_margin + info->var.hsync_len;
+	value = ((value * hmul / hdiv) / 8) - 5;
+	vga_wcrt(par->state.vgabase, 0x42, (value + 1) / 2);
+
+	if (screen_size > info->screen_size)
+		screen_size = info->screen_size;
+	memset_io(info->screen_base, 0x00, screen_size);
+	/* Device and screen back on */
+	svga_wcrt_mask(par->state.vgabase, 0x17, 0x80, 0x80);
+	svga_wseq_mask(par->state.vgabase, 0x01, 0x00, 0x20);
+
+	return 0;
+}
+
+/* Set a colour register */
+
+static int arkfb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
+				u_int transp, struct fb_info *fb)
+{
+	switch (fb->var.bits_per_pixel) {
+	case 0:
+	case 4:
+		if (regno >= 16)
+			return -EINVAL;
+
+		if ((fb->var.bits_per_pixel == 4) &&
+		    (fb->var.nonstd == 0)) {
+			outb(0xF0, VGA_PEL_MSK);
+			outb(regno*16, VGA_PEL_IW);
+		} else {
+			outb(0x0F, VGA_PEL_MSK);
+			outb(regno, VGA_PEL_IW);
+		}
+		outb(red >> 10, VGA_PEL_D);
+		outb(green >> 10, VGA_PEL_D);
+		outb(blue >> 10, VGA_PEL_D);
+		break;
+	case 8:
+		if (regno >= 256)
+			return -EINVAL;
+
+		outb(0xFF, VGA_PEL_MSK);
+		outb(regno, VGA_PEL_IW);
+		outb(red >> 10, VGA_PEL_D);
+		outb(green >> 10, VGA_PEL_D);
+		outb(blue >> 10, VGA_PEL_D);
+		break;
+	case 16:
+		if (regno >= 16)
+			return 0;
+
+		if (fb->var.green.length == 5)
+			((u32*)fb->pseudo_palette)[regno] = ((red & 0xF800) >> 1) |
+				((green & 0xF800) >> 6) | ((blue & 0xF800) >> 11);
+		else if (fb->var.green.length == 6)
+			((u32*)fb->pseudo_palette)[regno] = (red & 0xF800) |
+				((green & 0xFC00) >> 5) | ((blue & 0xF800) >> 11);
+		else
+			return -EINVAL;
+		break;
+	case 24:
+	case 32:
+		if (regno >= 16)
+			return 0;
+
+		((u32*)fb->pseudo_palette)[regno] = ((red & 0xFF00) << 8) |
+			(green & 0xFF00) | ((blue & 0xFF00) >> 8);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/* Set the display blanking state */
+
+static int arkfb_blank(int blank_mode, struct fb_info *info)
+{
+	struct arkfb_info *par = info->par;
+
+	switch (blank_mode) {
+	case FB_BLANK_UNBLANK:
+		fb_dbg(info, "unblank\n");
+		svga_wseq_mask(par->state.vgabase, 0x01, 0x00, 0x20);
+		svga_wcrt_mask(par->state.vgabase, 0x17, 0x80, 0x80);
+		break;
+	case FB_BLANK_NORMAL:
+		fb_dbg(info, "blank\n");
+		svga_wseq_mask(par->state.vgabase, 0x01, 0x20, 0x20);
+		svga_wcrt_mask(par->state.vgabase, 0x17, 0x80, 0x80);
+		break;
+	case FB_BLANK_POWERDOWN:
+	case FB_BLANK_HSYNC_SUSPEND:
+	case FB_BLANK_VSYNC_SUSPEND:
+		fb_dbg(info, "sync down\n");
+		svga_wseq_mask(par->state.vgabase, 0x01, 0x20, 0x20);
+		svga_wcrt_mask(par->state.vgabase, 0x17, 0x00, 0x80);
+		break;
+	}
+	return 0;
+}
+
+
+/* Pan the display */
+
+static int arkfb_pan_display(struct fb_var_screeninfo *var, struct fb_info *info)
+{
+	struct arkfb_info *par = info->par;
+	unsigned int offset;
+
+	/* Calculate the offset */
+	if (info->var.bits_per_pixel == 0) {
+		offset = (var->yoffset / 16) * (info->var.xres_virtual / 2)
+		       + (var->xoffset / 2);
+		offset = offset >> 2;
+	} else {
+		offset = (var->yoffset * info->fix.line_length) +
+			 (var->xoffset * info->var.bits_per_pixel / 8);
+		offset = offset >> ((info->var.bits_per_pixel == 4) ? 2 : 3);
+	}
+
+	/* Set the offset */
+	svga_wcrt_multi(par->state.vgabase, ark_start_address_regs, offset);
+
+	return 0;
+}
+
+
+/* ------------------------------------------------------------------------- */
+
+
+/* Frame buffer operations */
+
+static const struct fb_ops arkfb_ops = {
+	.owner		= THIS_MODULE,
+	.fb_open	= arkfb_open,
+	.fb_release	= arkfb_release,
+	__FB_DEFAULT_IOMEM_OPS_RDWR,
+	.fb_check_var	= arkfb_check_var,
+	.fb_set_par	= arkfb_set_par,
+	.fb_setcolreg	= arkfb_setcolreg,
+	.fb_blank	= arkfb_blank,
+	.fb_pan_display	= arkfb_pan_display,
+	.fb_fillrect	= arkfb_fillrect,
+	.fb_copyarea	= cfb_copyarea,
+	.fb_imageblit	= arkfb_imageblit,
+	__FB_DEFAULT_IOMEM_OPS_MMAP,
+	.fb_get_caps    = svga_get_caps,
+};
+
+
+/* ------------------------------------------------------------------------- */
+
+
+/* PCI probe */
+static int ark_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+	struct pci_bus_region bus_reg;
+	struct resource vga_res;
+	struct fb_info *info;
+	struct arkfb_info *par;
+	int rc;
+	u8 regval;
+
+	rc = aperture_remove_conflicting_pci_devices(dev, "arkfb");
+	if (rc < 0)
+		return rc;
+
+	/* Ignore secondary VGA device because there is no VGA arbitration */
+	if (! svga_primary_device(dev)) {
+		dev_info(&(dev->dev), "ignoring secondary device\n");
+		return -ENODEV;
+	}
+
+	/* Allocate and fill driver data structure */
+	info = framebuffer_alloc(sizeof(struct arkfb_info), &(dev->dev));
+	if (!info)
+		return -ENOMEM;
+
+	par = info->par;
+	mutex_init(&par->open_lock);
+
+	info->flags = FBINFO_PARTIAL_PAN_OK | FBINFO_HWACCEL_YPAN;
+	info->fbops = &arkfb_ops;
+
+	/* Prepare PCI device */
+	rc = pci_enable_device(dev);
+	if (rc < 0) {
+		dev_err(info->device, "cannot enable PCI device\n");
+		goto err_enable_device;
+	}
+
+	rc = pci_request_regions(dev, "arkfb");
+	if (rc < 0) {
+		dev_err(info->device, "cannot reserve framebuffer region\n");
+		goto err_request_regions;
+	}
+
+	par->dac = ics5342_init(ark_dac_read_regs, ark_dac_write_regs, info);
+	if (! par->dac) {
+		rc = -ENOMEM;
+		dev_err(info->device, "RAMDAC initialization failed\n");
+		goto err_dac;
+	}
+
+	info->fix.smem_start = pci_resource_start(dev, 0);
+	info->fix.smem_len = pci_resource_len(dev, 0);
+
+	/* Map physical IO memory address into kernel space */
+	info->screen_base = pci_iomap_wc(dev, 0, 0);
+	if (! info->screen_base) {
+		rc = -ENOMEM;
+		dev_err(info->device, "iomap for framebuffer failed\n");
+		goto err_iomap;
+	}
+
+	bus_reg.start = 0;
+	bus_reg.end = 64 * 1024;
+
+	vga_res.flags = IORESOURCE_IO;
+
+	pcibios_bus_to_resource(dev->bus, &vga_res, &bus_reg);
+
+	par->state.vgabase = (void __iomem *) (unsigned long) vga_res.start;
+
+	/* FIXME get memsize */
+	regval = vga_rseq(par->state.vgabase, 0x10);
+	info->screen_size = (1 << (regval >> 6)) << 20;
+	info->fix.smem_len = info->screen_size;
+
+	strcpy(info->fix.id, "ARK 2000PV");
+	info->fix.mmio_start = 0;
+	info->fix.mmio_len = 0;
+	info->fix.type = FB_TYPE_PACKED_PIXELS;
+	info->fix.visual = FB_VISUAL_PSEUDOCOLOR;
+	info->fix.ypanstep = 0;
+	info->fix.accel = FB_ACCEL_NONE;
+	info->pseudo_palette = (void*) (par->pseudo_palette);
+
+	/* Prepare startup mode */
+	rc = fb_find_mode(&(info->var), info, mode_option, NULL, 0, NULL, 8);
+	if (! ((rc == 1) || (rc == 2))) {
+		rc = -EINVAL;
+		dev_err(info->device, "mode %s not found\n", mode_option);
+		goto err_find_mode;
+	}
+
+	rc = fb_alloc_cmap(&info->cmap, 256, 0);
+	if (rc < 0) {
+		dev_err(info->device, "cannot allocate colormap\n");
+		goto err_alloc_cmap;
+	}
+
+	rc = register_framebuffer(info);
+	if (rc < 0) {
+		dev_err(info->device, "cannot register framebuffer\n");
+		goto err_reg_fb;
+	}
+
+	fb_info(info, "%s on %s, %d MB RAM\n",
+		info->fix.id, pci_name(dev), info->fix.smem_len >> 20);
+
+	/* Record a reference to the driver data */
+	pci_set_drvdata(dev, info);
+	par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
+					  info->fix.smem_len);
+	return 0;
+
+	/* Error handling */
+err_reg_fb:
+	fb_dealloc_cmap(&info->cmap);
+err_alloc_cmap:
+err_find_mode:
+	pci_iounmap(dev, info->screen_base);
+err_iomap:
+	dac_release(par->dac);
+err_dac:
+	pci_release_regions(dev);
+err_request_regions:
+/*	pci_disable_device(dev); */
+err_enable_device:
+	framebuffer_release(info);
+	return rc;
+}
+
+/* PCI remove */
+
+static void ark_pci_remove(struct pci_dev *dev)
+{
+	struct fb_info *info = pci_get_drvdata(dev);
+
+	if (info) {
+		struct arkfb_info *par = info->par;
+		arch_phys_wc_del(par->wc_cookie);
+		dac_release(par->dac);
+		unregister_framebuffer(info);
+		fb_dealloc_cmap(&info->cmap);
+
+		pci_iounmap(dev, info->screen_base);
+		pci_release_regions(dev);
+/*		pci_disable_device(dev); */
+
+		framebuffer_release(info);
+	}
+}
+
+
+/* PCI suspend */
+
+static int __maybe_unused ark_pci_suspend(struct device *dev)
+{
+	struct fb_info *info = dev_get_drvdata(dev);
+	struct arkfb_info *par = info->par;
+
+	dev_info(info->device, "suspend\n");
+
+	console_lock();
+	mutex_lock(&(par->open_lock));
+
+	if (par->ref_count == 0) {
+		mutex_unlock(&(par->open_lock));
+		console_unlock();
+		return 0;
+	}
+
+	fb_set_suspend(info, 1);
+
+	mutex_unlock(&(par->open_lock));
+	console_unlock();
+
+	return 0;
+}
+
+
+/* PCI resume */
+
+static int __maybe_unused ark_pci_resume(struct device *dev)
+{
+	struct fb_info *info = dev_get_drvdata(dev);
+	struct arkfb_info *par = info->par;
+
+	dev_info(info->device, "resume\n");
+
+	console_lock();
+	mutex_lock(&(par->open_lock));
+
+	if (par->ref_count == 0)
+		goto fail;
+
+	arkfb_set_par(info);
+	fb_set_suspend(info, 0);
+
+fail:
+	mutex_unlock(&(par->open_lock));
+	console_unlock();
+	return 0;
+}
+
+static const struct dev_pm_ops ark_pci_pm_ops = {
+#ifdef CONFIG_PM_SLEEP
+	.suspend	= ark_pci_suspend,
+	.resume		= ark_pci_resume,
+	.freeze		= NULL,
+	.thaw		= ark_pci_resume,
+	.poweroff	= ark_pci_suspend,
+	.restore	= ark_pci_resume,
+#endif
+};
+
+/* List of boards that we are trying to support */
+
+static const struct pci_device_id ark_devices[] = {
+	{PCI_DEVICE(0xEDD8, 0xA099)},
+	{0, 0, 0, 0, 0, 0, 0}
+};
+
+
+MODULE_DEVICE_TABLE(pci, ark_devices);
+
+static struct pci_driver arkfb_pci_driver = {
+	.name		= "arkfb",
+	.id_table	= ark_devices,
+	.probe		= ark_pci_probe,
+	.remove		= ark_pci_remove,
+	.driver.pm	= &ark_pci_pm_ops,
+};
+
+/* Cleanup */
+
+static void __exit arkfb_cleanup(void)
+{
+	pr_debug("arkfb: cleaning up\n");
+	pci_unregister_driver(&arkfb_pci_driver);
+}
+
+/* Driver Initialisation */
+
+static int __init arkfb_init(void)
+{
+
+#ifndef MODULE
+	char *option = NULL;
+#endif
+
+	if (fb_modesetting_disabled("arkfb"))
+		return -ENODEV;
+
+#ifndef MODULE
+	if (fb_get_options("arkfb", &option))
+		return -ENODEV;
+
+	if (option && *option)
+		mode_option = option;
+#endif
+
+	pr_debug("arkfb: initializing\n");
+	return pci_register_driver(&arkfb_pci_driver);
+}
+
+module_init(arkfb_init);
+module_exit(arkfb_cleanup);
-- 
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