/*
   *  linux/drivers/video/mdacon.c -- Low level MDA based console driver
   *
   *	(c) 1998 Andrew Apted <ajapted@netspace.net.au>
   *
   *      including portions (c) 1995-1998 Patrick Caulfield.
   *
   *      slight improvements (c) 2000 Edward Betts <edward@debian.org>
   *
   *  This file is based on the VGA console driver (vgacon.c):
   *	
   *	Created 28 Sep 1997 by Geert Uytterhoeven
   *
   *	Rewritten by Martin Mares <mj@ucw.cz>, July 1998
   *
   *  and on the old console.c, vga.c and vesa_blank.c drivers:
   *
   *	Copyright (C) 1991, 1992  Linus Torvalds
   *			    1995  Jay Estabrook
   *
   *  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.
   *
   *  Changelog:
   *  Paul G. (03/2001) Fix mdacon= boot prompt to use __setup().
   */
  
  #include <linux/types.h>
  #include <linux/fs.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/console.h>
  #include <linux/string.h>
  #include <linux/kd.h>
  #include <linux/vt_kern.h>
  #include <linux/vt_buffer.h>
  #include <linux/selection.h>
  #include <linux/spinlock.h>
  #include <linux/ioport.h>
  #include <linux/delay.h>
  #include <linux/init.h>
  
  #include <asm/io.h>
  #include <asm/vga.h>
  
  static DEFINE_SPINLOCK(mda_lock);
  
  /* description of the hardware layout */
  
  static unsigned long	mda_vram_base;		/* Base of video memory */
  static unsigned long	mda_vram_len;		/* Size of video memory */
  static unsigned int	mda_num_columns;	/* Number of text columns */
  static unsigned int	mda_num_lines;		/* Number of text lines */
  
  static unsigned int	mda_index_port;		/* Register select port */
  static unsigned int	mda_value_port;		/* Register value port */
  static unsigned int	mda_mode_port;		/* Mode control port */
  static unsigned int	mda_status_port;	/* Status and Config port */
  static unsigned int	mda_gfx_port;		/* Graphics control port */
  
  /* current hardware state */
  
  static int	mda_cursor_loc=-1;
  static int	mda_cursor_size_from=-1;
  static int	mda_cursor_size_to=-1;
  
  static enum { TYPE_MDA, TYPE_HERC, TYPE_HERCPLUS, TYPE_HERCCOLOR } mda_type;
  static char *mda_type_name;
  
  /* console information */
  
  static int	mda_first_vc = 13;
  static int	mda_last_vc  = 16;
  
  static struct vc_data	*mda_display_fg = NULL;
  
  module_param(mda_first_vc, int, 0);
  MODULE_PARM_DESC(mda_first_vc, "First virtual console. Default: 13");
  module_param(mda_last_vc, int, 0);
  MODULE_PARM_DESC(mda_last_vc, "Last virtual console. Default: 16");
  
  /* MDA register values
   */
  
  #define MDA_CURSOR_BLINKING	0x00
  #define MDA_CURSOR_OFF		0x20
  #define MDA_CURSOR_SLOWBLINK	0x60
  
  #define MDA_MODE_GRAPHICS	0x02
  #define MDA_MODE_VIDEO_EN	0x08
  #define MDA_MODE_BLINK_EN	0x20
  #define MDA_MODE_GFX_PAGE1	0x80
  
  #define MDA_STATUS_HSYNC	0x01
  #define MDA_STATUS_VSYNC	0x80
  #define MDA_STATUS_VIDEO	0x08
  
  #define MDA_CONFIG_COL132	0x08
  #define MDA_GFX_MODE_EN		0x01
  #define MDA_GFX_PAGE_EN		0x02
  
  
  /*
   * MDA could easily be classified as "pre-dinosaur hardware".
   */
  
  static void write_mda_b(unsigned int val, unsigned char reg)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&mda_lock, flags);	
  
  	outb_p(reg, mda_index_port); 
  	outb_p(val, mda_value_port);
  
  	spin_unlock_irqrestore(&mda_lock, flags);
  }
  
  static void write_mda_w(unsigned int val, unsigned char reg)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&mda_lock, flags);
  
  	outb_p(reg,   mda_index_port); outb_p(val >> 8,   mda_value_port);
  	outb_p(reg+1, mda_index_port); outb_p(val & 0xff, mda_value_port);
  
  	spin_unlock_irqrestore(&mda_lock, flags);
  }
  
  #ifdef TEST_MDA_B
  static int test_mda_b(unsigned char val, unsigned char reg)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&mda_lock, flags);
  
  	outb_p(reg, mda_index_port); 
  	outb  (val, mda_value_port);
  
  	udelay(20); val = (inb_p(mda_value_port) == val);
  
  	spin_unlock_irqrestore(&mda_lock, flags);
  	return val;
  }
  #endif
  
  static inline void mda_set_cursor(unsigned int location) 
  {
  	if (mda_cursor_loc == location)
  		return;
  
  	write_mda_w(location >> 1, 0x0e);
  
  	mda_cursor_loc = location;
  }
  
  static inline void mda_set_cursor_size(int from, int to)
  {
  	if (mda_cursor_size_from==from && mda_cursor_size_to==to)
  		return;
  	
  	if (from > to) {
  		write_mda_b(MDA_CURSOR_OFF, 0x0a);	/* disable cursor */
  	} else {
  		write_mda_b(from, 0x0a);	/* cursor start */
  		write_mda_b(to,   0x0b);	/* cursor end */
  	}
  
  	mda_cursor_size_from = from;
  	mda_cursor_size_to   = to;
  }
  
  
  #ifndef MODULE
  static int __init mdacon_setup(char *str)
  {
  	/* command line format: mdacon=<first>,<last> */
  
  	int ints[3];
  
  	str = get_options(str, ARRAY_SIZE(ints), ints);
  
  	if (ints[0] < 2)
  		return 0;
  
  	if (ints[1] < 1 || ints[1] > MAX_NR_CONSOLES || 
  	    ints[2] < 1 || ints[2] > MAX_NR_CONSOLES)
  		return 0;
  
  	mda_first_vc = ints[1];
  	mda_last_vc  = ints[2];
  	return 1;
  }
  
  __setup("mdacon=", mdacon_setup);
  #endif
  
  static int mda_detect(void)
  {
  	int count=0;
  	u16 *p, p_save;
  	u16 *q, q_save;
  
  	/* do a memory check */
  
  	p = (u16 *) mda_vram_base;
  	q = (u16 *) (mda_vram_base + 0x01000);
  
  	p_save = scr_readw(p); q_save = scr_readw(q);
  
  	scr_writew(0xAA55, p); if (scr_readw(p) == 0xAA55) count++;
  	scr_writew(0x55AA, p); if (scr_readw(p) == 0x55AA) count++;
  	scr_writew(p_save, p);
  
  	if (count != 2) {
  		return 0;
  	}
  
  	/* check if we have 4K or 8K */
  
  	scr_writew(0xA55A, q); scr_writew(0x0000, p);
  	if (scr_readw(q) == 0xA55A) count++;
  	
  	scr_writew(0x5AA5, q); scr_writew(0x0000, p);
  	if (scr_readw(q) == 0x5AA5) count++;
  
  	scr_writew(p_save, p); scr_writew(q_save, q);
  	
  	if (count == 4) {
  		mda_vram_len = 0x02000;
  	}
  	
  	/* Ok, there is definitely a card registering at the correct
  	 * memory location, so now we do an I/O port test.
  	 */
  
  #ifdef TEST_MDA_B
  	/* Edward: These two mess `tests' mess up my cursor on bootup */
  
  	/* cursor low register */
  	if (! test_mda_b(0x66, 0x0f)) {
  		return 0;
  	}
  
  	/* cursor low register */
  	if (! test_mda_b(0x99, 0x0f)) {
  		return 0;
  	}
  #endif
  
  	/* See if the card is a Hercules, by checking whether the vsync
  	 * bit of the status register is changing.  This test lasts for
  	 * approximately 1/10th of a second.
  	 */
  	
  	p_save = q_save = inb_p(mda_status_port) & MDA_STATUS_VSYNC;
  
  	for (count=0; count < 50000 && p_save == q_save; count++) {
  		q_save = inb(mda_status_port) & MDA_STATUS_VSYNC;
  		udelay(2);
  	}
  
  	if (p_save != q_save) {
  		switch (inb_p(mda_status_port) & 0x70) {
  			case 0x10:
  				mda_type = TYPE_HERCPLUS;
  				mda_type_name = "HerculesPlus";
  				break;
  			case 0x50:
  				mda_type = TYPE_HERCCOLOR;
  				mda_type_name = "HerculesColor";
  				break;
  			default:
  				mda_type = TYPE_HERC;
  				mda_type_name = "Hercules";
  				break;
  		}
  	}
  
  	return 1;
  }
  
  static void mda_initialize(void)
  {
  	write_mda_b(97, 0x00);		/* horizontal total */
  	write_mda_b(80, 0x01);		/* horizontal displayed */
  	write_mda_b(82, 0x02);		/* horizontal sync pos */
  	write_mda_b(15, 0x03);		/* horizontal sync width */
  
  	write_mda_b(25, 0x04);		/* vertical total */
  	write_mda_b(6,  0x05);		/* vertical total adjust */
  	write_mda_b(25, 0x06);		/* vertical displayed */
  	write_mda_b(25, 0x07);		/* vertical sync pos */
  
  	write_mda_b(2,  0x08);		/* interlace mode */
  	write_mda_b(13, 0x09);		/* maximum scanline */
  	write_mda_b(12, 0x0a);		/* cursor start */
  	write_mda_b(13, 0x0b);		/* cursor end */
  
  	write_mda_w(0x0000, 0x0c);	/* start address */
  	write_mda_w(0x0000, 0x0e);	/* cursor location */
  
  	outb_p(MDA_MODE_VIDEO_EN | MDA_MODE_BLINK_EN, mda_mode_port);
  	outb_p(0x00, mda_status_port);
  	outb_p(0x00, mda_gfx_port);
  }
  
  static const char *mdacon_startup(void)
  {
  	mda_num_columns = 80;
  	mda_num_lines   = 25;
  
  	mda_vram_len  = 0x01000;
  	mda_vram_base = VGA_MAP_MEM(0xb0000, mda_vram_len);
  
  	mda_index_port  = 0x3b4;
  	mda_value_port  = 0x3b5;
  	mda_mode_port   = 0x3b8;
  	mda_status_port = 0x3ba;
  	mda_gfx_port    = 0x3bf;
  
  	mda_type = TYPE_MDA;
  	mda_type_name = "MDA";
  
  	if (! mda_detect()) {
  		printk("mdacon: MDA card not detected.
  ");
  		return NULL;
  	}
  
  	if (mda_type != TYPE_MDA) {
  		mda_initialize();
  	}
  
  	/* cursor looks ugly during boot-up, so turn it off */
  	mda_set_cursor(mda_vram_len - 1);
  
  	printk("mdacon: %s with %ldK of memory detected.
  ",
  		mda_type_name, mda_vram_len/1024);
  
  	return "MDA-2";
  }
  
  static void mdacon_init(struct vc_data *c, int init)
  {
  	c->vc_complement_mask = 0x0800;	 /* reverse video */
  	c->vc_display_fg = &mda_display_fg;
  
  	if (init) {
  		c->vc_cols = mda_num_columns;
  		c->vc_rows = mda_num_lines;
  	} else
  		vc_resize(c, mda_num_columns, mda_num_lines);
  
  	/* make the first MDA console visible */
  
  	if (mda_display_fg == NULL)
  		mda_display_fg = c;
  }
  
  static void mdacon_deinit(struct vc_data *c)
  {
  	/* con_set_default_unimap(c->vc_num); */
  
  	if (mda_display_fg == c)
  		mda_display_fg = NULL;
  }
  
  static inline u16 mda_convert_attr(u16 ch)
  {
  	u16 attr = 0x0700;
  
  	/* Underline and reverse-video are mutually exclusive on MDA.
  	 * Since reverse-video is used for cursors and selected areas,
  	 * it takes precedence. 
  	 */
  
  	if (ch & 0x0800)	attr = 0x7000;	/* reverse */
  	else if (ch & 0x0400)	attr = 0x0100;	/* underline */
  
  	return ((ch & 0x0200) << 2) | 		/* intensity */ 
  		(ch & 0x8000) |			/* blink */ 
  		(ch & 0x00ff) | attr;
  }
  
  static u8 mdacon_build_attr(struct vc_data *c, u8 color, u8 intensity, 
  			    u8 blink, u8 underline, u8 reverse, u8 italic)
  {
  	/* The attribute is just a bit vector:
  	 *
  	 *	Bit 0..1 : intensity (0..2)
  	 *	Bit 2    : underline
  	 *	Bit 3    : reverse
  	 *	Bit 7    : blink
  	 */
  
  	return (intensity & 3) |
  		((underline & 1) << 2) |
  		((reverse   & 1) << 3) |
  		(!!italic << 4) |
  		((blink     & 1) << 7);
  }
  
  static void mdacon_invert_region(struct vc_data *c, u16 *p, int count)
  {
  	for (; count > 0; count--) {
  		scr_writew(scr_readw(p) ^ 0x0800, p);
  		p++;
  	}
  }
  
  #define MDA_ADDR(x,y)  ((u16 *) mda_vram_base + (y)*mda_num_columns + (x))
  
  static void mdacon_putc(struct vc_data *c, int ch, int y, int x)
  {
  	scr_writew(mda_convert_attr(ch), MDA_ADDR(x, y));
  }
  
  static void mdacon_putcs(struct vc_data *c, const unsigned short *s,
  		         int count, int y, int x)
  {
  	u16 *dest = MDA_ADDR(x, y);
  
  	for (; count > 0; count--) {
  		scr_writew(mda_convert_attr(scr_readw(s++)), dest++);
  	}
  }
  
  static void mdacon_clear(struct vc_data *c, int y, int x, 
  			  int height, int width)
  {
  	u16 *dest = MDA_ADDR(x, y);
  	u16 eattr = mda_convert_attr(c->vc_video_erase_char);
  
  	if (width <= 0 || height <= 0)
  		return;
  
  	if (x==0 && width==mda_num_columns) {
  		scr_memsetw(dest, eattr, height*width*2);
  	} else {
  		for (; height > 0; height--, dest+=mda_num_columns)
  			scr_memsetw(dest, eattr, width*2);
  	}
  }
                          
  static void mdacon_bmove(struct vc_data *c, int sy, int sx, 
  			 int dy, int dx, int height, int width)
  {
  	u16 *src, *dest;
  
  	if (width <= 0 || height <= 0)
  		return;
  		
  	if (sx==0 && dx==0 && width==mda_num_columns) {
  		scr_memmovew(MDA_ADDR(0,dy), MDA_ADDR(0,sy), height*width*2);
  
  	} else if (dy < sy || (dy == sy && dx < sx)) {
  		src  = MDA_ADDR(sx, sy);
  		dest = MDA_ADDR(dx, dy);
  
  		for (; height > 0; height--) {
  			scr_memmovew(dest, src, width*2);
  			src  += mda_num_columns;
  			dest += mda_num_columns;
  		}
  	} else {
  		src  = MDA_ADDR(sx, sy+height-1);
  		dest = MDA_ADDR(dx, dy+height-1);
  
  		for (; height > 0; height--) {
  			scr_memmovew(dest, src, width*2);
  			src  -= mda_num_columns;
  			dest -= mda_num_columns;
  		}
  	}
  }
  
  static int mdacon_switch(struct vc_data *c)
  {
  	return 1;	/* redrawing needed */
  }
  
  static int mdacon_set_palette(struct vc_data *c, unsigned char *table)
  {
  	return -EINVAL;
  }
  
  static int mdacon_blank(struct vc_data *c, int blank, int mode_switch)
  {
  	if (mda_type == TYPE_MDA) {
  		if (blank) 
  			scr_memsetw((void *)mda_vram_base, 
  				mda_convert_attr(c->vc_video_erase_char),
  				c->vc_screenbuf_size);
  		/* Tell console.c that it has to restore the screen itself */
  		return 1;
  	} else {
  		if (blank)
  			outb_p(0x00, mda_mode_port);	/* disable video */
  		else
  			outb_p(MDA_MODE_VIDEO_EN | MDA_MODE_BLINK_EN, 
  				mda_mode_port);
  		return 0;
  	}
  }
  
  static int mdacon_scrolldelta(struct vc_data *c, int lines)
  {
  	return 0;
  }
  
  static void mdacon_cursor(struct vc_data *c, int mode)
  {
  	if (mode == CM_ERASE) {
  		mda_set_cursor(mda_vram_len - 1);
  		return;
  	}
  
  	mda_set_cursor(c->vc_y*mda_num_columns*2 + c->vc_x*2);
  
  	switch (c->vc_cursor_type & 0x0f) {
  
  		case CUR_LOWER_THIRD:	mda_set_cursor_size(10, 13); break;
  		case CUR_LOWER_HALF:	mda_set_cursor_size(7,  13); break;
  		case CUR_TWO_THIRDS:	mda_set_cursor_size(4,  13); break;
  		case CUR_BLOCK:		mda_set_cursor_size(1,  13); break;
  		case CUR_NONE:		mda_set_cursor_size(14, 13); break;
  		default:		mda_set_cursor_size(12, 13); break;
  	}
  }
  
  static int mdacon_scroll(struct vc_data *c, int t, int b, int dir, int lines)
  {
  	u16 eattr = mda_convert_attr(c->vc_video_erase_char);
  
  	if (!lines)
  		return 0;
  
  	if (lines > c->vc_rows)   /* maximum realistic size */
  		lines = c->vc_rows;
  
  	switch (dir) {
  
  	case SM_UP:
  		scr_memmovew(MDA_ADDR(0,t), MDA_ADDR(0,t+lines),
  				(b-t-lines)*mda_num_columns*2);
  		scr_memsetw(MDA_ADDR(0,b-lines), eattr,
  				lines*mda_num_columns*2);
  		break;
  
  	case SM_DOWN:
  		scr_memmovew(MDA_ADDR(0,t+lines), MDA_ADDR(0,t),
  				(b-t-lines)*mda_num_columns*2);
  		scr_memsetw(MDA_ADDR(0,t), eattr, lines*mda_num_columns*2);
  		break;
  	}
  
  	return 0;
  }
  
  
  /*
   *  The console `switch' structure for the MDA based console
   */
  
  static const struct consw mda_con = {
  	.owner =		THIS_MODULE,
  	.con_startup =		mdacon_startup,
  	.con_init =		mdacon_init,
  	.con_deinit =		mdacon_deinit,
  	.con_clear =		mdacon_clear,
  	.con_putc =		mdacon_putc,
  	.con_putcs =		mdacon_putcs,
  	.con_cursor =		mdacon_cursor,
  	.con_scroll =		mdacon_scroll,
  	.con_bmove =		mdacon_bmove,
  	.con_switch =		mdacon_switch,
  	.con_blank =		mdacon_blank,
  	.con_set_palette =	mdacon_set_palette,
  	.con_scrolldelta =	mdacon_scrolldelta,
  	.con_build_attr =	mdacon_build_attr,
  	.con_invert_region =	mdacon_invert_region,
  };
  
  int __init mda_console_init(void)
  {
  	int err;
  
  	if (mda_first_vc > mda_last_vc)
  		return 1;
  	console_lock();
  	err = do_take_over_console(&mda_con, mda_first_vc-1, mda_last_vc-1, 0);
  	console_unlock();
  	return err;
  }
  
  static void __exit mda_console_exit(void)
  {
  	give_up_console(&mda_con);
  }
  
  module_init(mda_console_init);
  module_exit(mda_console_exit);
  
  MODULE_LICENSE("GPL");