/*
   *      linux/drivers/video/maxinefb.c
   *
   *	DECstation 5000/xx onboard framebuffer support ... derived from:
   *	"HP300 Topcat framebuffer support (derived from macfb of all things)
   *	Phil Blundell <philb@gnu.org> 1998", the original code can be
   *      found in the file hpfb.c in the same directory.
   *
   *      DECstation related code Copyright (C) 1999,2000,2001 by
   *      Michael Engel <engel@unix-ag.org> and
   *      Karsten Merker <merker@linuxtag.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.
   *
   */
  
  /*
   * Changes:
   * 2001/01/27 removed debugging and testing code, fixed fb_ops
   *            initialization which had caused a crash before,
   *            general cleanup, first official release (KM)
   *
   */
  
  #include <linux/module.h>
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/string.h>
  #include <linux/mm.h>
  #include <linux/delay.h>
  #include <linux/init.h>
  #include <linux/fb.h>
  #include <video/maxinefb.h>
  
  /* bootinfo.h defines the machine type values, needed when checking */
  /* whether are really running on a maxine, KM                       */
  #include <asm/bootinfo.h>
  
  static struct fb_info fb_info;
  
  static struct fb_var_screeninfo maxinefb_defined = {
  	.xres =		1024,
  	.yres =		768,
  	.xres_virtual =	1024,
  	.yres_virtual =	768,
  	.bits_per_pixel =8,
  	.activate =	FB_ACTIVATE_NOW,
  	.height =	-1,
  	.width =	-1,
  	.vmode =	FB_VMODE_NONINTERLACED,
  };
  
  static struct fb_fix_screeninfo maxinefb_fix = {
  	.id =		"Maxine",
  	.smem_len =	(1024*768),
  	.type =		FB_TYPE_PACKED_PIXELS,
  	.visual =	FB_VISUAL_PSEUDOCOLOR,
  	.line_length =	1024,
  };
  
  /* Handle the funny Inmos RamDAC/video controller ... */
  
  void maxinefb_ims332_write_register(int regno, register unsigned int val)
  {
  	register unsigned char *regs = (char *) MAXINEFB_IMS332_ADDRESS;
  	unsigned char *wptr;
  
  	wptr = regs + 0xa0000 + (regno << 4);
  	*((volatile unsigned int *) (regs)) = (val >> 8) & 0xff00;
  	*((volatile unsigned short *) (wptr)) = val;
  }
  
  unsigned int maxinefb_ims332_read_register(int regno)
  {
  	register unsigned char *regs = (char *) MAXINEFB_IMS332_ADDRESS;
  	unsigned char *rptr;
  	register unsigned int j, k;
  
  	rptr = regs + 0x80000 + (regno << 4);
  	j = *((volatile unsigned short *) rptr);
  	k = *((volatile unsigned short *) regs);
  
  	return (j & 0xffff) | ((k & 0xff00) << 8);
  }
  
  /* Set the palette */
  static int maxinefb_setcolreg(unsigned regno, unsigned red, unsigned green,
  			      unsigned blue, unsigned transp, struct fb_info *info)
  {
  	/* value to be written into the palette reg. */
  	unsigned long hw_colorvalue = 0;
  
  	if (regno > 255)
  		return 1;
  
  	red   >>= 8;    /* The cmap fields are 16 bits    */
  	green >>= 8;    /* wide, but the harware colormap */
  	blue  >>= 8;    /* registers are only 8 bits wide */
  
  	hw_colorvalue = (blue << 16) + (green << 8) + (red);
  
  	maxinefb_ims332_write_register(IMS332_REG_COLOR_PALETTE + regno,
  				       hw_colorvalue);
  	return 0;
  }
  
  static struct fb_ops maxinefb_ops = {
  	.owner		= THIS_MODULE,
  	.fb_setcolreg	= maxinefb_setcolreg,
  	.fb_fillrect	= cfb_fillrect,
  	.fb_copyarea	= cfb_copyarea,
  	.fb_imageblit	= cfb_imageblit,
  };
  
  int __init maxinefb_init(void)
  {
  	unsigned long fboff;
  	unsigned long fb_start;
  	int i;
  
  	if (fb_get_options("maxinefb", NULL))
  		return -ENODEV;
  
  	/* Validate we're on the proper machine type */
  	if (mips_machtype != MACH_DS5000_XX) {
  		return -EINVAL;
  	}
  
  	printk(KERN_INFO "Maxinefb: Personal DECstation detected
  ");
  	printk(KERN_INFO "Maxinefb: initializing onboard framebuffer
  ");
  
  	/* Framebuffer display memory base address */
  	fb_start = DS5000_xx_ONBOARD_FBMEM_START;
  
  	/* Clear screen */
  	for (fboff = fb_start; fboff < fb_start + 0x1ffff; fboff++)
  		*(volatile unsigned char *)fboff = 0x0;
  
  	maxinefb_fix.smem_start = fb_start;
  	
  	/* erase hardware cursor */
  	for (i = 0; i < 512; i++) {
  		maxinefb_ims332_write_register(IMS332_REG_CURSOR_RAM + i,
  					       0);
  		/*
  		   if (i&0x8 == 0)
  		   maxinefb_ims332_write_register (IMS332_REG_CURSOR_RAM + i, 0x0f);
  		   else
  		   maxinefb_ims332_write_register (IMS332_REG_CURSOR_RAM + i, 0xf0);
  		 */
  	}
  
  	fb_info.fbops = &maxinefb_ops;
  	fb_info.screen_base = (char *)maxinefb_fix.smem_start;
  	fb_info.var = maxinefb_defined;
  	fb_info.fix = maxinefb_fix;
  	fb_info.flags = FBINFO_DEFAULT;
  
  	fb_alloc_cmap(&fb_info.cmap, 256, 0);
  
  	if (register_framebuffer(&fb_info) < 0)
  		return 1;
  	return 0;
  }
  
  static void __exit maxinefb_exit(void)
  {
  	unregister_framebuffer(&fb_info);
  }
  
  #ifdef MODULE
  MODULE_LICENSE("GPL");
  #endif
  module_init(maxinefb_init);
  module_exit(maxinefb_exit);