/*
   *  linux/drivers/video/fm2fb.c -- BSC FrameMaster II/Rainbow II frame buffer
   *				   device
   *
   *	Copyright (C) 1998 Steffen A. Mork (linux-dev@morknet.de)
   *	Copyright (C) 1999 Geert Uytterhoeven
   *
   *  Written for 2.0.x by Steffen A. Mork
   *  Ported to 2.1.x by Geert Uytterhoeven
   *  Ported to new api by James Simmons
   *
   *  This file is subject to the terms and conditions of the GNU General Public
   *  License. See the file COPYING in the main directory of this archive for
   *  more details.
   */
  
  #include <linux/module.h>
  #include <linux/mm.h>
  #include <linux/fb.h>
  #include <linux/init.h>
  #include <linux/zorro.h>
  #include <asm/io.h>
  
  /*
   *	Some technical notes:
   *
   *	The BSC FrameMaster II (or Rainbow II) is a simple very dumb
   *	frame buffer which allows to display 24 bit true color images.
   *	Each pixel is 32 bit width so it's very easy to maintain the
   *	frame buffer. One long word has the following layout:
   *	AARRGGBB which means: AA the alpha channel byte, RR the red
   *	channel, GG the green channel and BB the blue channel.
   *
   *	The FrameMaster II supports the following video modes.
   *	- PAL/NTSC
   *	- interlaced/non interlaced
   *	- composite sync/sync/sync over green
   *
   *	The resolution is to the following both ones:
   *	- 768x576 (PAL)
   *	- 768x480 (NTSC)
   *
   *	This means that pixel access per line is fixed due to the
   *	fixed line width. In case of maximal resolution the frame
   *	buffer needs an amount of memory of 1.769.472 bytes which
   *	is near to 2 MByte (the allocated address space of Zorro2).
   *	The memory is channel interleaved. That means every channel
   *	owns four VRAMs. Unfortunately most FrameMasters II are
   *	not assembled with memory for the alpha channel. In this
   *	case it could be possible to add the frame buffer into the
   *	normal memory pool.
   *
   *	At relative address 0x1ffff8 of the frame buffers base address
   *	there exists a control register with the number of
   *	four control bits. They have the following meaning:
   *	bit value meaning
   *
   *	 0    1   0=interlaced/1=non interlaced
   *	 1    2   0=video out disabled/1=video out enabled
   *	 2    4   0=normal mode as jumpered via JP8/1=complement mode
   *	 3    8   0=read  onboard ROM/1 normal operation (required)
   *
   *	As mentioned above there are several jumper. I think there
   *	is not very much information about the FrameMaster II in
   *	the world so I add these information for completeness.
   *
   *	JP1  interlace selection (1-2 non interlaced/2-3 interlaced)
   *	JP2  wait state creation (leave as is!)
   *	JP3  wait state creation (leave as is!)
   *	JP4  modulate composite sync on green output (1-2 composite
   *	     sync on green channel/2-3 normal composite sync)
   *	JP5  create test signal, shorting this jumper will create
   *	     a white screen
   *	JP6  sync creation (1-2 composite sync/2-3 H-sync output)
   *	JP8  video mode (1-2 PAL/2-3 NTSC)
   *
   *	With the following jumpering table you can connect the
   *	FrameMaster II to a normal TV via SCART connector:
   *	JP1:  2-3
   *	JP4:  2-3
   *	JP6:  2-3
   *	JP8:  1-2 (means PAL for Europe)
   *
   *	NOTE:
   *	There is no other possibility to change the video timings
   *	except the interlaced/non interlaced, sync control and the
   *	video mode PAL (50 Hz)/NTSC (60 Hz). Inside this
   *	FrameMaster II driver are assumed values to avoid anomalies
   *	to a future X server. Except the pixel clock is really
   *	constant at 30 MHz.
   *
   *	9 pin female video connector:
   *
   *	1  analog red 0.7 Vss
   *	2  analog green 0.7 Vss
   *	3  analog blue 0.7 Vss
   *	4  H-sync TTL
   *	5  V-sync TTL
   *	6  ground
   *	7  ground
   *	8  ground
   *	9  ground
   *
   *	Some performance notes:
   *	The FrameMaster II was not designed to display a console
   *	this driver would do! It was designed to display still true
   *	color images. Imagine: When scroll up a text line there
   *	must copied ca. 1.7 MBytes to another place inside this
   *	frame buffer. This means 1.7 MByte read and 1.7 MByte write
   *	over the slow 16 bit wide Zorro2 bus! A scroll of one
   *	line needs 1 second so do not expect to much from this
   *	driver - he is at the limit!
   *
   */
  
  /*
   *	definitions
   */
  
  #define FRAMEMASTER_SIZE	0x200000
  #define FRAMEMASTER_REG		0x1ffff8
  
  #define FRAMEMASTER_NOLACE	1
  #define FRAMEMASTER_ENABLE	2
  #define FRAMEMASTER_COMPL	4
  #define FRAMEMASTER_ROM		8
  
  static volatile unsigned char *fm2fb_reg;
  
  static struct fb_fix_screeninfo fb_fix = {
  	.smem_len =	FRAMEMASTER_REG,
  	.type =		FB_TYPE_PACKED_PIXELS,
  	.visual =	FB_VISUAL_TRUECOLOR,
  	.line_length =	(768 << 2),
  	.mmio_len =	(8),
  	.accel =	FB_ACCEL_NONE,
  };
  
  static int fm2fb_mode = -1;
  
  #define FM2FB_MODE_PAL	0
  #define FM2FB_MODE_NTSC	1
  
  static struct fb_var_screeninfo fb_var_modes[] = {
      {
  	/* 768 x 576, 32 bpp (PAL) */
  	768, 576, 768, 576, 0, 0, 32, 0,
  	{ 16, 8, 0 }, { 8, 8, 0 }, { 0, 8, 0 }, { 24, 8, 0 },
  	0, FB_ACTIVATE_NOW, -1, -1, FB_ACCEL_NONE,
  	33333, 10, 102, 10, 5, 80, 34, FB_SYNC_COMP_HIGH_ACT, 0
      }, {
  	/* 768 x 480, 32 bpp (NTSC - not supported yet */
  	768, 480, 768, 480, 0, 0, 32, 0,
  	{ 16, 8, 0 }, { 8, 8, 0 }, { 0, 8, 0 }, { 24, 8, 0 },
  	0, FB_ACTIVATE_NOW, -1, -1, FB_ACCEL_NONE,
  	33333, 10, 102, 10, 5, 80, 34, FB_SYNC_COMP_HIGH_ACT, 0
      }
  };
  
      /*
       *  Interface used by the world
       */
  
  static int fm2fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                             u_int transp, struct fb_info *info);
  static int fm2fb_blank(int blank, struct fb_info *info);
  
  static struct fb_ops fm2fb_ops = {
  	.owner		= THIS_MODULE,
  	.fb_setcolreg	= fm2fb_setcolreg,
  	.fb_blank	= fm2fb_blank,
  	.fb_fillrect	= cfb_fillrect,
  	.fb_copyarea	= cfb_copyarea,
  	.fb_imageblit	= cfb_imageblit,
  };
  
      /*
       *  Blank the display.
       */
  static int fm2fb_blank(int blank, struct fb_info *info)
  {
  	unsigned char t = FRAMEMASTER_ROM;
  
  	if (!blank)
  		t |= FRAMEMASTER_ENABLE | FRAMEMASTER_NOLACE;
  	fm2fb_reg[0] = t;
  	return 0;
  }
  
      /*
       *  Set a single color register. The values supplied are already
       *  rounded down to the hardware's capabilities (according to the
       *  entries in the var structure). Return != 0 for invalid regno.
       */
  static int fm2fb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
                           u_int transp, struct fb_info *info)
  {
  	if (regno < 16) {
  		red >>= 8;
  		green >>= 8;
  		blue >>= 8;
  
  		((u32*)(info->pseudo_palette))[regno] = (red << 16) |
  			(green << 8) | blue;
  	}
  
  	return 0;
  }
  
      /*
       *  Initialisation
       */
  
  static int fm2fb_probe(struct zorro_dev *z, const struct zorro_device_id *id);
  
  static struct zorro_device_id fm2fb_devices[] = {
  	{ ZORRO_PROD_BSC_FRAMEMASTER_II },
  	{ ZORRO_PROD_HELFRICH_RAINBOW_II },
  	{ 0 }
  };
  MODULE_DEVICE_TABLE(zorro, fm2fb_devices);
  
  static struct zorro_driver fm2fb_driver = {
  	.name		= "fm2fb",
  	.id_table	= fm2fb_devices,
  	.probe		= fm2fb_probe,
  };
  
  static int fm2fb_probe(struct zorro_dev *z, const struct zorro_device_id *id)
  {
  	struct fb_info *info;
  	unsigned long *ptr;
  	int is_fm;
  	int x, y;
  
  	is_fm = z->id == ZORRO_PROD_BSC_FRAMEMASTER_II;
  
  	if (!zorro_request_device(z,"fm2fb"))
  		return -ENXIO;
  
  	info = framebuffer_alloc(16 * sizeof(u32), &z->dev);
  	if (!info) {
  		zorro_release_device(z);
  		return -ENOMEM;
  	}
  
  	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
  		framebuffer_release(info);
  		zorro_release_device(z);
  		return -ENOMEM;
  	}
  
  	/* assigning memory to kernel space */
  	fb_fix.smem_start = zorro_resource_start(z);
  	info->screen_base = ioremap(fb_fix.smem_start, FRAMEMASTER_SIZE);
  	fb_fix.mmio_start = fb_fix.smem_start + FRAMEMASTER_REG;
  	fm2fb_reg  = (unsigned char *)(info->screen_base+FRAMEMASTER_REG);
  
  	strcpy(fb_fix.id, is_fm ? "FrameMaster II" : "Rainbow II");
  
  	/* make EBU color bars on display */
  	ptr = (unsigned long *)fb_fix.smem_start;
  	for (y = 0; y < 576; y++) {
  		for (x = 0; x < 96; x++) *ptr++ = 0xffffff;/* white */
  		for (x = 0; x < 96; x++) *ptr++ = 0xffff00;/* yellow */
  		for (x = 0; x < 96; x++) *ptr++ = 0x00ffff;/* cyan */
  		for (x = 0; x < 96; x++) *ptr++ = 0x00ff00;/* green */
  		for (x = 0; x < 96; x++) *ptr++ = 0xff00ff;/* magenta */
  		for (x = 0; x < 96; x++) *ptr++ = 0xff0000;/* red */
  		for (x = 0; x < 96; x++) *ptr++ = 0x0000ff;/* blue */
  		for (x = 0; x < 96; x++) *ptr++ = 0x000000;/* black */
  	}
  	fm2fb_blank(0, info);
  
  	if (fm2fb_mode == -1)
  		fm2fb_mode = FM2FB_MODE_PAL;
  
  	info->fbops = &fm2fb_ops;
  	info->var = fb_var_modes[fm2fb_mode];
  	info->pseudo_palette = info->par;
  	info->par = NULL;
  	info->fix = fb_fix;
  	info->flags = FBINFO_DEFAULT;
  
  	if (register_framebuffer(info) < 0) {
  		fb_dealloc_cmap(&info->cmap);
  		iounmap(info->screen_base);
  		framebuffer_release(info);
  		zorro_release_device(z);
  		return -EINVAL;
  	}
  	fb_info(info, "%s frame buffer device
  ", fb_fix.id);
  	return 0;
  }
  
  int __init fm2fb_setup(char *options)
  {
  	char *this_opt;
  
  	if (!options || !*options)
  		return 0;
  
  	while ((this_opt = strsep(&options, ",")) != NULL) {
  		if (!strncmp(this_opt, "pal", 3))
  			fm2fb_mode = FM2FB_MODE_PAL;
  		else if (!strncmp(this_opt, "ntsc", 4))
  			fm2fb_mode = FM2FB_MODE_NTSC;
  	}
  	return 0;
  }
  
  int __init fm2fb_init(void)
  {
  	char *option = NULL;
  
  	if (fb_get_options("fm2fb", &option))
  		return -ENODEV;
  	fm2fb_setup(option);
  	return zorro_register_driver(&fm2fb_driver);
  }
  
  module_init(fm2fb_init);
  MODULE_LICENSE("GPL");