[PATCH] epson1355fb: salvage epson1355 code from James' tree

This patch was submitted by James Hoover < ch@hpl.hp.com> to James a long
time ago (2.5 development) which ports the epson driver to 2.6.  Took the
code from James tree to be hopefully included in the mm tree so it can get
more testing.

Signed-off-by:  Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 620 insertions, 414 deletions

diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 86b26b707806ae..3af3de82cff426 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -416,35 +416,15 @@ config FB_PVR2
 	  (<file:drivers/video/pvr2fb.c>). Please see the file
 	  <file:Documentation/fb/pvr2fb.txt>.
 
-config FB_E1355
+config FB_EPSON1355
 	bool "Epson 1355 framebuffer support"
-	depends on FB && SUPERH
+	depends on FB && (SUPERH || ARCH_CEIVA)
 	help
 	  Build in support for the SED1355 Epson Research Embedded RAMDAC
 	  LCD/CRT Controller (since redesignated as the S1D13505) as a
 	  framebuffer.  Product specs at
 	  <http://www.erd.epson.com/vdc/html/products.htm>.
 
-config E1355_REG_BASE
-	hex "Register Base Address"
-	depends on FB_E1355
-	default "a8000000"
-	help
-	  Epson SED1355/S1D13505 LCD/CRT controller register base address.
-	  See the manuals at
-	  <http://www.erd.epson.com/vdc/html/contents/S1D13505.htm> for
-	  discussion.
-
-config E1355_FB_BASE
-	hex "Framebuffer Base Address"
-	depends on FB_E1355
-	default "a8200000"
-	help
-	  Epson SED1355/S1D13505 LCD/CRT controller memory base address.  See
-	  the manuals at
-	  <http://www.erd.epson.com/vdc/html/contents/S1D13505.htm> for
-	  discussion.
-
 config FB_RIVA
 	tristate "nVidia Riva support"
 	depends on FB && PCI
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index 7c9c95435f2e10..8033b89981d93d 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -70,7 +70,7 @@ obj-$(CONFIG_FB_HGA)              += hgafb.o cfbfillrect.o cfbcopyarea.o cfbimgb
 obj-$(CONFIG_FB_SA1100)           += sa1100fb.o cfbfillrect.o cfbcopyarea.o cfbimgblt.o
 obj-$(CONFIG_FB_VIRTUAL)          += vfb.o cfbfillrect.o cfbcopyarea.o cfbimgblt.o 
 obj-$(CONFIG_FB_HIT)              += hitfb.o cfbfillrect.o cfbimgblt.o
-obj-$(CONFIG_FB_E1355)            += epson1355fb.o
+obj-$(CONFIG_FB_EPSON1355)	  += epson1355fb.o cfbfillrect.o cfbcopyarea.o cfbimgblt.o
 obj-$(CONFIG_FB_PVR2)             += pvr2fb.o cfbfillrect.o cfbcopyarea.o cfbimgblt.o
 obj-$(CONFIG_FB_KYRO)             += kyro/ cfbfillrect.o cfbcopyarea.o cfbimgblt.o
 obj-$(CONFIG_FB_VOODOO1)          += sstfb.o cfbfillrect.o cfbcopyarea.o cfbimgblt.o
diff --git a/drivers/video/epson1355fb.c b/drivers/video/epson1355fb.c
index a0294d8154e6a0..dc040cc7ba2686 100644
--- a/drivers/video/epson1355fb.c
+++ b/drivers/video/epson1355fb.c
@@ -1,541 +1,767 @@
 /*
- * linux/drivers/video/epson1355fb.c
- *	-- Support for the Epson SED1355 LCD/CRT controller
+ * linux/drivers/video/epson1355fb.c -- Epson S1D13505 frame buffer for 2.5.
  *
- * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
+ * Epson Research S1D13505 Embedded RAMDAC LCD/CRT Controller
+ *   (previously known as SED1355)
  *
- * based on linux/drivers/video/skeletonfb.c, which was
+ * Cf. http://www.erd.epson.com/vdc/html/S1D13505.html
+ *
+ *
+ * Copyright (C) Hewlett-Packard Company.  All rights reserved.
+ *
+ * Written by Christopher Hoover <ch@hpl.hp.com>
+ *
+ * Adapted from:
+ *
+ *  linux/drivers/video/skeletonfb.c
+ *  Modified to new api Jan 2001 by James Simmons (jsimmons@infradead.org)
  *  Created 28 Dec 1997 by Geert Uytterhoeven
  *
+ *  linux/drivers/video/epson1355fb.c (2.4 driver)
+ *  Copyright (C) 2000 Philipp Rumpf <prumpf@tux.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.
- */
-/* TODO (roughly in order of priority):
- * 16 bpp support
- * crt support
- * hw cursor support
- * SwivelView
+ * License. See the file COPYING in the main directory of this archive for
+ * more details.
+ *
+ *
+ * Noteworthy Issues
+ * -----------------
+ *
+ * This driver is complicated by the fact that this is a 16-bit chip
+ * and, on at least one platform (ceiva), we can only do 16-bit reads
+ * and writes to the framebuffer.  We hide this from user space
+ * except in the case of mmap().
+ *
+ *
+ * To Do
+ * -----
+ *
+ * - Test 8-bit pseudocolor mode
+ * - Allow setting bpp, virtual resolution
+ * - Implement horizontal panning
+ * - (maybe) Implement hardware cursor
  */
 
-#include <asm/io.h>
-#include <linux/config.h>
-#include <linux/delay.h>
-#include <linux/errno.h>
-#include <linux/fb.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#include <linux/mm.h>
 #include <linux/module.h>
-#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
 #include <linux/string.h>
+#include <linux/mm.h>
 #include <linux/tty.h>
-#include <video/fbcon-cfb8.h>
-#include <video/fbcon-mfb.h>
-#include <video/fbcon.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <asm/types.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#include <video/epson1355.h>
 
-/* Register defines.  The docs don't seem to provide nice mnemonic names
- * so I made them up myself ... */
+struct epson1355_par {
+	unsigned long reg_addr;
+};
 
-#define E1355_PANEL	0x02
-#define E1355_DISPLAY	0x0D
-#define E1355_MISC	0x1B
-#define E1355_GPIO	0x20
-#define E1355_LUT_INDEX 0x24
-#define E1355_LUT_DATA	0x26
+/* ------------------------------------------------------------------------- */
 
 #ifdef CONFIG_SUPERH
-#define E1355_REG_BASE	CONFIG_E1355_REG_BASE
-#define E1355_FB_BASE	CONFIG_E1355_FB_BASE
 
-static inline u8 e1355_read_reg(int index)
+static inline u8 epson1355_read_reg(int index)
 {
-	return ctrl_inb(E1355_REG_BASE + index);
+	return ctrl_inb(par.reg_addr + index);
 }
 
-static inline void e1355_write_reg(u8 data, int index)
+static inline void epson1355_write_reg(u8 data, int index)
 {
-	ctrl_outb(data, E1355_REG_BASE + index);
+	ctrl_outb(data, par.reg_addr + index);
 }
 
-static inline u16 e1355_read_reg16(int index)
+#elif defined(CONFIG_ARM)
+
+# ifdef CONFIG_ARCH_CEIVA
+#  include <asm/arch/hardware.h>
+#  define EPSON1355FB_BASE_PHYS	(CEIVA_PHYS_SED1355)
+# endif
+
+static inline u8 epson1355_read_reg(struct epson1355_par *par, int index)
 {
-	return e1355_read_reg(index) + (e1355_read_reg(index+1) << 8);
+	return __raw_readb(par->reg_addr + index);
 }
 
-static inline void e1355_write_reg16(u16 data, int index)
+static inline void epson1355_write_reg(struct epson1355_par *par, u8 data, int index)
 {
-	e1355_write_reg((data&0xff), index);
-	e1355_write_reg(((data>>8)&0xff), index + 1);
+	__raw_writeb(data, par->reg_addr + index);
 }
+
 #else
-#error unknown architecture
+# error "no architecture-specific epson1355_{read,write}_reg"
 #endif
 
-struct e1355fb_info {
-	struct fb_info_gen gen;
-};
-
-static int current_par_valid = 0;
-static struct display disp;
+#ifndef EPSON1355FB_BASE_PHYS
+# error  "EPSON1355FB_BASE_PHYS is not defined"
+#endif
 
-static struct fb_var_screeninfo default_var;
+#define EPSON1355FB_REGS_OFS	(0)
+#define EPSON1355FB_REGS_PHYS	(EPSON1355FB_BASE_PHYS + EPSON1355FB_REGS_OFS)
+#define EPSON1355FB_REGS_LEN	(64)
 
-int e1355fb_init(void);
-int e1355fb_setup(char*);
-static int e1355_encode_var(struct fb_var_screeninfo *var, const void *par,
-			    struct fb_info_gen *info);
-/* ------------------- chipset specific functions -------------------------- */
+#define EPSON1355FB_FB_OFS	(0x00200000)
+#define EPSON1355FB_FB_PHYS	(EPSON1355FB_BASE_PHYS + EPSON1355FB_FB_OFS)
+#define EPSON1355FB_FB_LEN	(2 * 1024 * 1024)
 
+/* ------------------------------------------------------------------------- */
 
-static void disable_hw_cursor(void)
+static inline u16 epson1355_read_reg16(struct epson1355_par *par, int index)
 {
-	u8 curs;
+	u8 lo = epson1355_read_reg(par, index);
+	u8 hi = epson1355_read_reg(par, index + 1);
 
-	curs = e1355_read_reg(0x27);
-	curs &= ~0xc0;
-	e1355_write_reg(curs, 0x27);
+	return (hi << 8) | lo;
 }
 
-static void e1355_detect(void)
+static inline void epson1355_write_reg16(struct epson1355_par *par, u16 data, int index)
 {
-	u8 rev;
+	u8 lo = data & 0xff;
+	u8 hi = (data >> 8) & 0xff;
 
-	e1355_write_reg(0x00, E1355_MISC);
+	epson1355_write_reg(par, lo, index);
+	epson1355_write_reg(par, hi, index + 1);
+}
 
-	rev = e1355_read_reg(0x00);
+static inline u32 epson1355_read_reg20(struct epson1355_par *par, int index)
+{
+	u8 b0 = epson1355_read_reg(par, index);
+	u8 b1 = epson1355_read_reg(par, index + 1);
+	u8 b2 = epson1355_read_reg(par, index + 2);
 
-	if ((rev & 0xfc) != 0x0c) {
-		printk(KERN_WARNING "Epson 1355 not detected\n");
-	}
+	return (b2 & 0x0f) << 16 | (b1 << 8) | b0;
+}
 
-	/* XXX */
-	disable_hw_cursor();
+static inline void epson1355_write_reg20(struct epson1355_par *par, u32 data, int index)
+{
+	u8 b0 = data & 0xff;
+	u8 b1 = (data >> 8) & 0xff;
+	u8 b2 = (data >> 16) & 0x0f;
 
-	e1355_encode_var(&default_var, NULL, NULL);
+	epson1355_write_reg(par, b0, index);
+	epson1355_write_reg(par, b1, index + 1);
+	epson1355_write_reg(par, b2, index + 2);
 }
 
-struct e1355_par {
-	u32 xres;
-	u32 yres;
+/* ------------------------------------------------------------------------- */
 
-	int bpp;
-	int mem_bpp;
+static void set_lut(struct epson1355_par *par, u8 index, u8 r, u8 g, u8 b)
+{
+	epson1355_write_reg(par, index, REG_LUT_ADDR);
+	epson1355_write_reg(par, r, REG_LUT_DATA);
+	epson1355_write_reg(par, g, REG_LUT_DATA);
+	epson1355_write_reg(par, b, REG_LUT_DATA);
+}
 
-	u32 panel_xres;
-	u32 panel_yres;
-	
-	int panel_width;
-	int panel_ymul;
-};
 
-static int e1355_encode_fix(struct fb_fix_screeninfo *fix,
-			    const void *raw_par,
-			    struct fb_info_gen *info)
+/**
+ *  	epson1355fb_setcolreg - sets a color register.
+ *      @regno: Which register in the CLUT we are programming
+ *      @red: The red value which can be up to 16 bits wide
+ *	@green: The green value which can be up to 16 bits wide
+ *	@blue:  The blue value which can be up to 16 bits wide.
+ *	@transp: If supported the alpha value which can be up to 16 bits wide.
+ *      @info: frame buffer info structure
+ *
+ *	Returns negative errno on error, or zero on success.
+ */
+static int epson1355fb_setcolreg(unsigned regno, unsigned r, unsigned g,
+				 unsigned b, unsigned transp,
+				 struct fb_info *info)
 {
-	const struct e1355_par *par = raw_par;
-	
-	memset(fix, 0, sizeof *fix);
-	
-	fix->type= FB_TYPE_PACKED_PIXELS;
-
-	if (!par)
-		BUG();
+	struct epson1355_par *par = info->par;
 
-	if (par->bpp == 1) {
-		fix->visual = FB_VISUAL_MONO10;
-	} else if (par->bpp <= 8) {
-		fix->visual = FB_VISUAL_PSEUDOCOLOR;
-	} else {
-		fix->visual = FB_VISUAL_TRUECOLOR;
-	}
+	if (info->var.grayscale)
+		r = g = b = (19595 * r + 38470 * g + 7471 * b) >> 16;
 
-	return 0;
-}
+	switch (info->fix.visual) {
+	case FB_VISUAL_TRUECOLOR:
+		if (regno >= 16)
+			return -EINVAL;
 
-static int e1355_set_bpp(struct e1355_par *par, int bpp)
-{
-	int code;
-	u8 disp;
-	u16 bytes_per_line;
-
-	switch(bpp) {
-	case 1:
-		code = 0; break;
-	case 2:
-		code = 1; break;
-	case 4:
-		code = 2; break;
-	case 8:
-		code = 3; break;
-	case 16:
-		code = 5; break;
-	default:
-		return -EINVAL; break;
-	}
+		((u32 *) info->pseudo_palette)[regno] =
+		    (r & 0xf800) | (g & 0xfc00) >> 5 | (b & 0xf800) >> 11;
 
-	disp = e1355_read_reg(E1355_DISPLAY);
-	disp &= ~0x1c;
-	disp |= code << 2;
-	e1355_write_reg(disp, E1355_DISPLAY);
-	
-	bytes_per_line = (par->xres * bpp) >> 3;
-	
-	e1355_write_reg16(bytes_per_line, 0x16);
+		break;
+	case FB_VISUAL_PSEUDOCOLOR:
+		if (regno >= 256)
+			return -EINVAL;
 
-	par->bpp = bpp;
+		set_lut(par, regno, r >> 8, g >> 8, b >> 8);
 
+		break;
+	default:
+		return -ENOSYS;
+	}
 	return 0;
 }
-		
-static int e1355_decode_var(const struct fb_var_screeninfo *var,
-			    void *raw_par,
-			    struct fb_info_gen *info)
+
+/* ------------------------------------------------------------------------- */
+
+/**
+ *      epson1355fb_pan_display - Pans the display.
+ *      @var: frame buffer variable screen structure
+ *      @info: frame buffer structure that represents a single frame buffer
+ *
+ *	Pan (or wrap, depending on the `vmode' field) the display using the
+ *  	`xoffset' and `yoffset' fields of the `var' structure.
+ *  	If the values don't fit, return -EINVAL.
+ *
+ *      Returns negative errno on error, or zero on success.
+ */
+static int epson1355fb_pan_display(struct fb_var_screeninfo *var,
+				   struct fb_info *info)
 {
-	struct e1355_par *par = raw_par;
-	int ret;
+	struct epson1355_par *par = info->par;
+	u32 start;
 
-	if (!par)
-		BUG();
+	if (var->xoffset != 0)	/* not yet ... */
+		return -EINVAL;
 
-	/*
-	 * Don't allow setting any of these yet: xres and yres don't
-	 * make sense for LCD panels; xres_virtual and yres_virtual
-	 * should be supported fine by our hardware though.
-	 */
-	if (var->xres != par->xres ||
-	    var->yres != par->yres ||
-	    var->xres != var->xres_virtual ||
-	    var->yres != var->yres_virtual ||
-	    var->xoffset != 0 ||
-	    var->yoffset != 0)
+	if (var->yoffset + info->var.yres > info->var.yres_virtual)
 		return -EINVAL;
 
-	if(var->bits_per_pixel != par->bpp) {
-		ret = e1355_set_bpp(par, var->bits_per_pixel);
+	start = (info->fix.line_length >> 1) * var->yoffset;
+
+	epson1355_write_reg20(par, start, REG_SCRN1_DISP_START_ADDR0);
 
-		if (ret)
-			goto out_err;
-	}
-		
 	return 0;
+}
 
- out_err:
-	return ret;
+/* ------------------------------------------------------------------------- */
+
+static void lcd_enable(struct epson1355_par *par, int enable)
+{
+	u8 mode = epson1355_read_reg(par, REG_DISPLAY_MODE);
+
+	if (enable)
+		mode |= 1;
+	else
+		mode &= ~1;
+
+	epson1355_write_reg(par, mode, REG_DISPLAY_MODE);
 }
 
-static void dump_panel_data(void)
+#if defined(CONFIG_ARCH_CEIVA)
+static void backlight_enable(int enable)
+{
+	/* ### this should be protected by a spinlock ... */
+	u8 pddr = clps_readb(PDDR);
+	if (enable)
+		pddr |= (1 << 5);
+	else
+		pddr &= ~(1 << 5);
+	clps_writeb(pddr, PDDR);
+}
+#else
+static void backlight_enable(int enable)
 {
-	u8 panel = e1355_read_reg(E1355_PANEL);
-	int width[2][4] = { { 4, 8, 16, -1 }, { 9, 12, 16, -1 } };
-
-	printk("%s %s %s panel, width %d bits\n",
-	       panel & 2 ? "dual" : "single",
-	       panel & 4 ? "color" : "mono",
-	       panel & 1 ? "TFT" : "passive",
-	       width[panel&1][(panel>>4)&3]);
-
-	printk("resolution %d x %d\n",
-	       (e1355_read_reg(0x04) + 1) * 8,
-	       ((e1355_read_reg16(0x08) + 1) * (1 + ((panel & 3) == 2))));
 }
+#endif
 
-static int e1355_bpp_to_var(int bpp, struct fb_var_screeninfo *var)
+
+/**
+ *      epson1355fb_blank - blanks the display.
+ *      @blank_mode: the blank mode we want.
+ *      @info: frame buffer structure that represents a single frame buffer
+ *
+ *      Blank the screen if blank_mode != 0, else unblank. Return 0 if
+ *      blanking succeeded, != 0 if un-/blanking failed due to e.g. a
+ *      video mode which doesn't support it. Implements VESA suspend
+ *      and powerdown modes on hardware that supports disabling hsync/vsync:
+ *      blank_mode == 2: suspend vsync
+ *      blank_mode == 3: suspend hsync
+ *      blank_mode == 4: powerdown
+ *
+ *      Returns negative errno on error, or zero on success.
+ *
+ */
+static int epson1355fb_blank(int blank_mode, struct fb_info *info)
 {
-	switch(bpp) {
-	case 1:
-	case 2:
-	case 4:
-	case 8:
-		var->bits_per_pixel = bpp;
-		var->red.offset = var->green.offset = var->blue.offset = 0;
-		var->red.length = var->green.length = var->blue.length = bpp;
+	struct epson1355_par *par = info->par;
+
+	switch (blank_mode) {
+	case VESA_NO_BLANKING:
+		lcd_enable(par, 1);
+		backlight_enable(1);
 		break;
-	case 16:
-		var->bits_per_pixel = 16;
-		var->red.offset = 11;
-		var->red.length = 5;
-		var->green.offset = 5;
-		var->green.length = 6;
-		var->blue.offset = 0;
-		var->blue.length = 5;
+	case VESA_VSYNC_SUSPEND:
+	case VESA_HSYNC_SUSPEND:
+		backlight_enable(0);
+		break;
+	case VESA_POWERDOWN:
+		backlight_enable(0);
+		lcd_enable(par, 0);
 		break;
+	default:
+		return -EINVAL;
 	}
-
 	return 0;
 }
 
-static int e1355_encode_var(struct fb_var_screeninfo *var, const void *raw_par,
-			    struct fb_info_gen *info)
-{
-	u8 panel, display;
-	u32 xres, xres_virtual, yres;
-	static int width[2][4] = { { 4, 8, 16, -1 }, { 9, 12, 16, -1 } };
-	static int bpp_tab[8] = { 1, 2, 4, 8, 15, 16 };
-	int bpp, hw_bpp;
-	int is_color, is_dual, is_tft;
-	int lcd_enabled, crt_enabled;
+/* ------------------------------------------------------------------------- */
 
-	panel = e1355_read_reg(E1355_PANEL);
-	display = e1355_read_reg(E1355_DISPLAY);
+/*
+ * We can't use the cfb generic routines, as we have to limit
+ * ourselves to 16-bit or 8-bit loads and stores to this 16-bit
+ * chip.
+ */
 
-	is_color = (panel & 0x04) != 0;
-	is_dual  = (panel & 0x02) != 0;
-	is_tft   = (panel & 0x01) != 0;
+static inline void epson1355fb_fb_writel(unsigned long v, unsigned long *a)
+{
+	u16 *p = (u16 *) a;
+	u16 l = v & 0xffff;
+	u16 h = v >> 16;
 
-	bpp = bpp_tab[(display>>2)&7]; 
-	e1355_bpp_to_var(bpp, var);
+	fb_writew(l, p);
+	fb_writew(h, p + 1);
+}
 
-	crt_enabled = (display & 0x02) != 0;
-	lcd_enabled = (display & 0x02) != 0;
+static inline unsigned long epson1355fb_fb_readl(const unsigned long *a)
+{
+	const u16 *p = (u16 *) a;
+	u16 l = fb_readw(p);
+	u16 h = fb_readw(p + 1);
 
-	hw_bpp = width[is_tft][(panel>>4)&3];
+	return (h << 16) | l;
+}
 
-	xres = e1355_read_reg(0x04) + 1;
-	yres = e1355_read_reg16(0x08) + 1;
-	
-	xres *= 8;
-	/* talk about weird hardware .. */
-	yres *= (is_dual && !crt_enabled) ? 2 : 1;
+#define FB_READL epson1355fb_fb_readl
+#define FB_WRITEL epson1355fb_fb_writel
 
-	xres_virtual = e1355_read_reg16(0x16);
-	/* it's in 2-byte words initially */
-	xres_virtual *= 16;
-	xres_virtual /= var->bits_per_pixel;
+/* ------------------------------------------------------------------------- */
 
-	var->xres = xres;
-	var->yres = yres;
-	var->xres_virtual = xres_virtual;
-	var->yres_virtual = yres;
+static inline unsigned long copy_from_user16(void *to, const void *from,
+					     unsigned long n)
+{
+	u16 *dst = (u16 *) to;
+	u16 *src = (u16 *) from;
 
-	var->xoffset = var->yoffset = 0;
+	if (!access_ok(VERIFY_READ, from, n))
+		return n;
 
-	var->grayscale = !is_color;
-	
-	return 0;
-}
+	while (n > 1) {
+		u16 v;
+		if (__get_user(v, src))
+			return n;
 
-#define is_dual(panel) (((panel)&3)==2)
+		fb_writew(v, dst);
 
-static void get_panel_data(struct e1355_par *par)
-{
-	u8 panel;
-	int width[2][4] = { { 4, 8, 16, -1 }, { 9, 12, 16, -1 } };
+		src++, dst++;
+		n -= 2;
+	}
+
+	if (n) {
+		u8 v;
 
-	panel = e1355_read_reg(E1355_PANEL);
+		if (__get_user(v, ((u8 *) src)))
+			return n;
 
-	par->panel_width = width[panel&1][(panel>>4)&3];
-	par->panel_xres = (e1355_read_reg(0x04) + 1) * 8;
-	par->panel_ymul = is_dual(panel) ? 2 : 1;
-	par->panel_yres = ((e1355_read_reg16(0x08) + 1)
-			   * par->panel_ymul);
+		fb_writeb(v, dst);
+	}
+	return 0;
 }
 
-static void e1355_get_par(void *raw_par, struct fb_info_gen *info)
+static inline unsigned long copy_to_user16(void *to, const void *from,
+					   unsigned long n)
 {
-	struct e1355_par *par = raw_par;
+	u16 *dst = (u16 *) to;
+	u16 *src = (u16 *) from;
 
-	get_panel_data(par);
-}
+	if (!access_ok(VERIFY_WRITE, to, n))
+		return n;
 
-static void e1355_set_par(const void *par, struct fb_info_gen *info)
-{
-}
+	while (n > 1) {
+		u16 v = fb_readw(src);
 
-static int e1355_getcolreg(unsigned regno, unsigned *red, unsigned *green,
-			   unsigned *blue, unsigned *transp,
-			   struct fb_info *info)
-{
-	u8 r, g, b;
+		if (__put_user(v, dst))
+			return n;
 
-	e1355_write_reg(regno, E1355_LUT_INDEX);
-	r = e1355_read_reg(E1355_LUT_DATA);
-	g = e1355_read_reg(E1355_LUT_DATA);
-	b = e1355_read_reg(E1355_LUT_DATA);
+		src++, dst++;
+		n -= 2;
+	}
 
-	*red = r << 8;
-	*green = g << 8;
-	*blue = b << 8;
+	if (n) {
+		u8 v = fb_readb(src);
 
+		if (__put_user(v, ((u8 *) dst)))
+			return n;
+	}
 	return 0;
 }
 
-static int e1355fb_setcolreg(unsigned regno, unsigned red, unsigned green,
-			     unsigned blue, unsigned transp,
-			     struct fb_info *info)
+
+static ssize_t
+epson1355fb_read(struct file *file, char *buf, size_t count, loff_t * ppos)
 {
-	u8 r = (red >> 8) & 0xf0;
-	u8 g = (green>>8) & 0xf0;
-	u8 b = (blue>> 8) & 0xf0;
-
-	e1355_write_reg(regno, E1355_LUT_INDEX);
-	e1355_write_reg(r, E1355_LUT_DATA);
-	e1355_write_reg(g, E1355_LUT_DATA);
-	e1355_write_reg(b, E1355_LUT_DATA);
-	
-	return 0;
+	struct inode *inode = file->f_dentry->d_inode;
+	int fbidx = iminor(inode);
+	struct fb_info *info = registered_fb[fbidx];
+	unsigned long p = *ppos;
+
+	/* from fbmem.c except for our own copy_*_user */
+	if (!info || !info->screen_base)
+		return -ENODEV;
+
+	if (p >= info->fix.smem_len)
+		return 0;
+	if (count >= info->fix.smem_len)
+		count = info->fix.smem_len;
+	if (count + p > info->fix.smem_len)
+		count = info->fix.smem_len - p;
+
+	if (count) {
+		char *base_addr;
+
+		base_addr = info->screen_base;
+		count -= copy_to_user16(buf, base_addr + p, count);
+		if (!count)
+			return -EFAULT;
+		*ppos += count;
+	}
+	return count;
 }
 
-static int e1355_pan_display(const struct fb_var_screeninfo *var,
-			     struct fb_info_gen *info)
+static ssize_t
+epson1355fb_write(struct file *file, const char *buf,
+		  size_t count, loff_t * ppos)
 {
-	BUG();
-	
-	return -EINVAL;
-}
+	struct inode *inode = file->f_dentry->d_inode;
+	int fbidx = iminor(inode);
+	struct fb_info *info = registered_fb[fbidx];
+	unsigned long p = *ppos;
+	int err;
+
+	/* from fbmem.c except for our own copy_*_user */
+	if (!info || !info->screen_base)
+		return -ENODEV;
+
+	/* from fbmem.c except for our own copy_*_user */
+	if (p > info->fix.smem_len)
+		return -ENOSPC;
+	if (count >= info->fix.smem_len)
+		count = info->fix.smem_len;
+	err = 0;
+	if (count + p > info->fix.smem_len) {
+		count = info->fix.smem_len - p;
+		err = -ENOSPC;
+	}
 
-/*
- * The AERO_HACKS parts disable/enable the backlight on the Compaq Aero 8000.
- * I'm not sure they aren't dangerous to the hardware, so be warned.
- */
-#undef AERO_HACKS
+	if (count) {
+		char *base_addr;
 
-static int e1355_blank(int blank_mode, struct fb_info_gen *info)
-{
-	u8 disp;
+		base_addr = info->screen_base;
+		count -= copy_from_user16(base_addr + p, buf, count);
+		*ppos += count;
+		err = -EFAULT;
+	}
+	if (count)
+		return count;
+	return err;
+}
 
-	switch (blank_mode) {
-	case VESA_NO_BLANKING:
-		disp = e1355_read_reg(E1355_DISPLAY);
-		disp |= 1;
-		e1355_write_reg(disp, E1355_DISPLAY);
- 		
-#ifdef AERO_HACKS
-		e1355_write_reg(0x6, 0x20);
-#endif
-		break;
+/* ------------------------------------------------------------------------- */
+
+static struct fb_ops epson1355fb_fbops = {
+	.owner 		= THIS_MODULE,
+	.fb_setcolreg 	= epson1355fb_setcolreg,
+	.fb_pan_display = epson1355fb_pan_display,
+	.fb_blank 	= epson1355fb_blank,
+	.fb_fillrect 	= cfb_fillrect,
+	.fb_copyarea 	= cfb_copyarea,
+	.fb_imageblit 	= cfb_imageblit,
+	.fb_read 	= epson1355fb_read,
+	.fb_write 	= epson1355fb_write,
+	.fb_cursor 	= soft_cursor,
+};
 
-	case VESA_VSYNC_SUSPEND:
-	case VESA_HSYNC_SUSPEND:
-	case VESA_POWERDOWN:
-		disp = e1355_read_reg(E1355_DISPLAY);
-		disp &= ~1;
-		e1355_write_reg(disp, E1355_DISPLAY);
+/* ------------------------------------------------------------------------- */
 
-#ifdef AERO_HACKS
-		e1355_write_reg(0x0, 0x20);
-#endif
-		break;
+static __init unsigned int get_fb_size(struct fb_info *info)
+{
+	unsigned int size = 2 * 1024 * 1024;
+	char *p = info->screen_base;
 
-	default:
-		return -EINVAL;
-	}
+	/* the 512k framebuffer is aliased at start + 0x80000 * n */
+	fb_writeb(1, p);
+	fb_writeb(0, p + 0x80000);
+	if (!fb_readb(p))
+		size = 512 * 1024;
 
-	return 0;
+	fb_writeb(0, p);
+
+	return size;
 }
 
-static struct display_switch e1355_dispsw;
+static int epson1355_width_tab[2][4] __initdata =
+    { {4, 8, 16, -1}, {9, 12, 16, -1} };
+static int epson1355_bpp_tab[8] __initdata = { 1, 2, 4, 8, 15, 16 };
 
-static void e1355_set_disp(const void *unused, struct display *disp,
-			   struct fb_info_gen *info)
+static void __init fetch_hw_state(struct fb_info *info, struct epson1355_par *par)
 {
-	struct display_switch *d;
+	struct fb_var_screeninfo *var = &info->var;
+	struct fb_fix_screeninfo *fix = &info->fix;
+	u8 panel, display;
+	u16 offset;
+	u32 xres, yres;
+	u32 xres_virtual, yres_virtual;
+	int bpp, lcd_bpp;
+	int is_color, is_dual, is_tft;
+	int lcd_enabled, crt_enabled;
 
-	disp->dispsw = &e1355_dispsw;
-	
-	switch(disp->var.bits_per_pixel) {
-#ifdef FBCON_HAS_MFB
-	case 1:
-		d = &fbcon_mfb; break;
-#endif	       
-#ifdef FBCON_HAS_CFB8
+	fix->type = FB_TYPE_PACKED_PIXELS;
+
+	display = epson1355_read_reg(par, REG_DISPLAY_MODE);
+	bpp = epson1355_bpp_tab[(display >> 2) & 7];
+
+	switch (bpp) {
 	case 8:
-		d = &fbcon_cfb8; break;
-#endif
+		fix->visual = FB_VISUAL_PSEUDOCOLOR;
+		var->bits_per_pixel = 8;
+		var->red.offset = var->green.offset = var->blue.offset = 0;
+		var->red.length = var->green.length = var->blue.length = 8;
+		break;
+	case 16:
+		/* 5-6-5 RGB */
+		fix->visual = FB_VISUAL_TRUECOLOR;
+		var->bits_per_pixel = 16;
+		var->red.offset = 11;
+		var->red.length = 5;
+		var->green.offset = 5;
+		var->green.length = 6;
+		var->blue.offset = 0;
+		var->blue.length = 5;
+		break;
 	default:
-		BUG(); break;
+		BUG();
 	}
+	fb_alloc_cmap(&(info->cmap), 256, 0);
 
-	memcpy(&e1355_dispsw, d, sizeof *d);
+	panel = epson1355_read_reg(par, REG_PANEL_TYPE);
+	is_color = (panel & 0x04) != 0;
+	is_dual = (panel & 0x02) != 0;
+	is_tft = (panel & 0x01) != 0;
+	crt_enabled = (display & 0x02) != 0;
+	lcd_enabled = (display & 0x01) != 0;
+	lcd_bpp = epson1355_width_tab[is_tft][(panel >> 4) & 3];
 
-	/* reading is terribly slow for us */
-#if 0 /* XXX: need to work out why this doesn't work */
-	e1355_dispsw.bmove = fbcon_redraw_bmove;
-#endif
-}
+	xres = (epson1355_read_reg(par, REG_HORZ_DISP_WIDTH) + 1) * 8;
+	yres = (epson1355_read_reg16(par, REG_VERT_DISP_HEIGHT0) + 1) *
+	    ((is_dual && !crt_enabled) ? 2 : 1);
+	offset = epson1355_read_reg16(par, REG_MEM_ADDR_OFFSET0) & 0x7ff;
+	xres_virtual = offset * 16 / bpp;
+	yres_virtual = fix->smem_len / (offset * 2);
+
+	var->xres = xres;
+	var->yres = yres;
+	var->xres_virtual = xres_virtual;
+	var->yres_virtual = yres_virtual;
+	var->xoffset = var->yoffset = 0;
 
-/* ------------ Interfaces to hardware functions ------------ */
+	fix->line_length = offset * 2;
 
+	fix->xpanstep = 0;	/* no pan yet */
+	fix->ypanstep = 1;
+	fix->ywrapstep = 0;
+	fix->accel = FB_ACCEL_NONE;
 
-struct fbgen_hwswitch e1355_switch = {
-	.detect =	e1355_detect,
-	.encode_fix =	e1355_encode_fix,
-	.decode_var =	e1355_decode_var,
-	.encode_var =	e1355_encode_var,
-	.get_par =	e1355_get_par,
-	.set_par =	e1355_set_par,
-	.getcolreg =	e1355_getcolreg,
-	.pan_display =	e1355_pan_display,
-	.blank =	e1355_blank,
-	.set_disp =	e1355_set_disp,
-};
+	var->grayscale = !is_color;
 
+#ifdef DEBUG
+	printk(KERN_INFO
+	       "epson1355fb: xres=%d, yres=%d, "
+	       "is_color=%d, is_dual=%d, is_tft=%d\n",
+	       xres, yres, is_color, is_dual, is_tft);
+	printk(KERN_INFO
+	       "epson1355fb: bpp=%d, lcd_bpp=%d, "
+	       "crt_enabled=%d, lcd_enabled=%d\n",
+	       bpp, lcd_bpp, crt_enabled, lcd_enabled);
+#endif
+}
 
-/* ------------ Hardware Independent Functions ------------ */
 
+static void clearfb16(struct fb_info *info)
+{
+	u16 *dst = (u16 *) info->screen_base;
+	unsigned long n = info->fix.smem_len;
 
-static struct fb_ops e1355fb_ops = {
-	.owner =	THIS_MODULE,
-	.fb_get_fix =	fbgen_get_fix,
-	.fb_get_var =	fbgen_get_var,
-	.fb_set_var =	fbgen_set_var,
-	.fb_get_cmap =	fbgen_get_cmap,
-	.fb_set_cmap =	gen_set_cmap,
-	.fb_setcolreg =	e1355fb_setcolreg,
-	.fb_pan_display =fbgen_pan_display,
-	.fb_blank =	fbgen_blank,
-};
+	while (n > 1) {
+		fb_writew(0, dst);
+		dst++, n -= 2;
+	}
 
-static struct e1355fb_info fb_info;
+	if (n)
+		fb_writeb(0, dst);
+}
 
-int __init e1355fb_setup(char *str)
+static void epson1355fb_platform_release(struct device *device)
 {
-	return 0;
 }
 
-int __init e1355fb_init(void)
+static int epson1355fb_remove(struct device *device)
 {
-	fb_info.gen.fbhw = &e1355_switch;
-	fb_info.gen.fbhw->detect();
-	strcpy(fb_info.gen.info.modename, "SED1355");
-	fb_info.gen.info.changevar = NULL;
-	fb_info.gen.info.fbops = &e1355fb_ops;
-	fb_info.gen.info.screen_base = (void *)E1355_FB_BASE;
-	fb_info.gen.currcon = -1;
-	fb_info.gen.info.disp = &disp;
-	fb_info.gen.parsize = sizeof(struct e1355_par);
-	fb_info.gen.info.switch_con = &fbgen_switch;
-	fb_info.gen.info.updatevar = &fbgen_update_var;
-	fb_info.gen.info.flags = FBINFO_DEFAULT;
-	/* This should give a reasonable default video mode */
-	fbgen_get_var(&disp.var, -1, &fb_info.gen.info);
-	fbgen_do_set_var(&disp.var, 1, &fb_info.gen);
-	fbgen_set_disp(-1, &fb_info.gen);
-	if (disp.var.bits_per_pixel > 1) 
-		do_install_cmap(0, &fb_info.gen);
-	if (register_framebuffer(&fb_info.gen.info) < 0)
-		return -EINVAL;
-	printk(KERN_INFO "fb%d: %s frame buffer device\n", fb_info.gen.info.node,
-	       fb_info.gen.info.modename);
+	struct fb_info *info = dev_get_drvdata(device);
+	struct epson1355_par *par = info->par;
+
+	backlight_enable(0);
+	if (par) {
+		lcd_enable(par, 0);
+		if (par && par->reg_addr)
+			iounmap((void *) par->reg_addr);
+	}
 
+	if (info) {
+		fb_dealloc_cmap(&info->cmap);
+		if (info->screen_base)
+			iounmap(info->screen_base);
+		framebuffer_release(info);
+	}
+	release_mem_region(EPSON1355FB_FB_PHYS, EPSON1355FB_FB_LEN);
+	release_mem_region(EPSON1355FB_REGS_PHYS, EPSON1355FB_REGS_LEN);
 	return 0;
 }
 
+int __init epson1355fb_probe(struct device *device)
+{
+	struct platform_device *dev = to_platform_device(device);
+	struct epson1355_par *default_par;
+	struct fb_info *info;
+	u8 revision;
+	int rc = 0;
+
+	if (!request_mem_region(EPSON1355FB_REGS_PHYS, EPSON1355FB_REGS_LEN, "S1D13505 registers")) {
+		printk(KERN_ERR "epson1355fb: unable to reserve "
+		       "registers at 0x%0x\n", EPSON1355FB_REGS_PHYS);
+		rc = -EBUSY;
+		goto bail;
+	}
+
+	if (!request_mem_region(EPSON1355FB_FB_PHYS, EPSON1355FB_FB_LEN,
+				"S1D13505 framebuffer")) {
+		printk(KERN_ERR "epson1355fb: unable to reserve "
+		       "framebuffer at 0x%0x\n", EPSON1355FB_FB_PHYS);
+		rc = -EBUSY;
+		goto bail;
+	}
 
-    /*
-     *  Cleanup
-     */
+	info = framebuffer_alloc(sizeof(struct epson1355_par) + sizeof(u32) * 256, &dev->dev);
+	if (!info)
+		rc = -ENOMEM;
+		goto bail;
+
+	default_par = info->par;
+	default_par->reg_addr = (unsigned long) ioremap(EPSON1355FB_REGS_PHYS, EPSON1355FB_REGS_LEN);
+	if (!default_par->reg_addr) {
+		printk(KERN_ERR "epson1355fb: unable to map registers\n");
+		rc = -ENOMEM;
+		goto bail;
+	}
+	info->pseudo_palette = (void *)(default_par + 1);
 
-void e1355fb_cleanup(struct fb_info *info)
-{
+	info->screen_base = ioremap(EPSON1355FB_FB_PHYS, EPSON1355FB_FB_LEN);
+	if (!info->screen_base) {
+		printk(KERN_ERR "epson1355fb: unable to map framebuffer\n");
+		rc = -ENOMEM;
+		goto bail;
+	}
+
+	revision = epson1355_read_reg(default_par, REG_REVISION_CODE);
+	if ((revision >> 2) != 3) {
+		printk(KERN_INFO "epson1355fb: epson1355 not found\n");
+		rc = -ENODEV;
+		goto bail;
+	}
+
+	info->fix.mmio_start = EPSON1355FB_REGS_PHYS;
+	info->fix.mmio_len = EPSON1355FB_REGS_LEN;
+	info->fix.smem_start = EPSON1355FB_FB_PHYS;
+	info->fix.smem_len = get_fb_size(info);
+
+	printk(KERN_INFO "epson1355fb: regs mapped at 0x%lx, fb %d KiB mapped at 0x%p\n",
+	       default_par->reg_addr, info->fix.smem_len / 1024, info->screen_base);
+
+	strcpy(info->fix.id, "S1D13505");
+	info->par = default_par;
+	info->fbops = &epson1355fb_fbops;
+	info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
+
+	/* we expect the boot loader to have initialized the chip
+	   with appropriate parameters from which we can determinte
+	   the flavor of lcd panel attached */
+	fetch_hw_state(info, default_par);
+
+	/* turn this puppy on ... */
+	clearfb16(info);
+	backlight_enable(1);
+	lcd_enable(default_par, 1);
+
+	if (register_framebuffer(info) < 0) {
+		rc = -EINVAL;
+		goto bail;
+	}
 	/*
-	 *  If your driver supports multiple boards, you should unregister and
-	 *  clean up all instances.
+	 * Our driver data.
 	 */
+	dev_set_drvdata(&dev->dev, info);
+
+	printk(KERN_INFO "fb%d: %s frame buffer device\n",
+	       info->node, info->fix.id);
+
+	return 0;
+
+      bail:
+	epson1355fb_remove(device);
+	return rc;
+}
+
+static struct device_driver epson1355fb_driver = {
+	.name	= "epson1355fb",
+	.bus	= &platform_bus_type,
+	.probe	= epson1355fb_probe,
+	.remove	= epson1355fb_remove,
+};
+
+static struct platform_device epson1355fb_device = {
+	.name	= "epson1355fb",
+	.id	= 0,
+	.dev	= {
+		.release = epson1355fb_platform_release,
+	}
+};
+
+int __init epson1355fb_init(void)
+{
+	int ret = 0;
+
+	ret = driver_register(&epson1355fb_driver);
+	if (!ret) {
+		ret = platform_device_register(&epson1355fb_device);
+		if (ret)
+			driver_unregister(&epson1355fb_driver);
+	}
+	return ret;
+}
 	
-	unregister_framebuffer(info);
-	/* ... */
+#ifdef MODULE
+static void __exit epson1355fb_exit(void)
+{
+	platform_device_unregister(&epson1355fb_device);
+	driver_unregister(&epson1355fb_driver);
 }
 
+/* ------------------------------------------------------------------------- */
+
+module_init(epson1355fb_init);
+module_exit(epson1355fb_exit);
+#endif
+
+MODULE_AUTHOR("Christopher Hoover <ch@hpl.hp.com>");
+MODULE_DESCRIPTION("Framebuffer driver for Epson S1D13505");
 MODULE_LICENSE("GPL");