/*
   * linux/drivers/video/hgafb.c -- Hercules graphics adaptor frame buffer device
   * 
   *      Created 25 Nov 1999 by Ferenc Bakonyi (fero@drama.obuda.kando.hu)
   *      Based on skeletonfb.c by Geert Uytterhoeven and
   *               mdacon.c by Andrew Apted
   *
   * History:
   *
   * - Revision 0.1.8 (23 Oct 2002): Ported to new framebuffer api.
   * 
   * - Revision 0.1.7 (23 Jan 2001): fix crash resulting from MDA only cards 
   *				   being detected as Hercules.	 (Paul G.)
   * - Revision 0.1.6 (17 Aug 2000): new style structs
   *                                 documentation
   * - Revision 0.1.5 (13 Mar 2000): spinlocks instead of saveflags();cli();etc
   *                                 minor fixes
   * - Revision 0.1.4 (24 Jan 2000): fixed a bug in hga_card_detect() for 
   *                                  HGA-only systems
   * - Revision 0.1.3 (22 Jan 2000): modified for the new fb_info structure
   *                                 screen is cleared after rmmod
   *                                 virtual resolutions
   *                                 module parameter 'nologo={0|1}'
   *                                 the most important: boot logo :)
   * - Revision 0.1.0  (6 Dec 1999): faster scrolling and minor fixes
   * - First release  (25 Nov 1999)
   *
   * 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/kernel.h>
  #include <linux/errno.h>
  #include <linux/spinlock.h>
  #include <linux/string.h>
  #include <linux/mm.h>

  #include <linux/delay.h>
  #include <linux/fb.h>
  #include <linux/init.h>
  #include <linux/ioport.h>

  #include <linux/platform_device.h>

  #include <asm/io.h>
  #include <asm/vga.h>
  
  #if 0
  #define DPRINTK(args...) printk(KERN_DEBUG __FILE__": " ##args)
  #else
  #define DPRINTK(args...)
  #endif
  
  #if 0
  #define CHKINFO(ret) if (info != &fb_info) { printk(KERN_DEBUG __FILE__": This should never happen, line:%d 
  ", __LINE__); return ret; }
  #else
  #define CHKINFO(ret)
  #endif
  
  /* Description of the hardware layout */
  
  static void __iomem *hga_vram;			/* Base of video memory */
  static unsigned long hga_vram_len;		/* Size of video memory */
  
  #define HGA_ROWADDR(row) ((row%4)*8192 + (row>>2)*90)
  #define HGA_TXT			0
  #define HGA_GFX			1
  
  static inline u8 __iomem * rowaddr(struct fb_info *info, u_int row)
  {
  	return info->screen_base + HGA_ROWADDR(row);
  }
  
  static int hga_mode = -1;			/* 0 = txt, 1 = gfx mode */
  
  static enum { TYPE_HERC, TYPE_HERCPLUS, TYPE_HERCCOLOR } hga_type;
  static char *hga_type_name;
  
  #define HGA_INDEX_PORT		0x3b4		/* Register select port */
  #define HGA_VALUE_PORT		0x3b5		/* Register value port */
  #define HGA_MODE_PORT		0x3b8		/* Mode control port */
  #define HGA_STATUS_PORT		0x3ba		/* Status and Config port */
  #define HGA_GFX_PORT		0x3bf		/* Graphics control port */
  
  /* HGA register values */
  
  #define HGA_CURSOR_BLINKING	0x00
  #define HGA_CURSOR_OFF		0x20
  #define HGA_CURSOR_SLOWBLINK	0x60
  
  #define HGA_MODE_GRAPHICS	0x02
  #define HGA_MODE_VIDEO_EN	0x08
  #define HGA_MODE_BLINK_EN	0x20
  #define HGA_MODE_GFX_PAGE1	0x80
  
  #define HGA_STATUS_HSYNC	0x01
  #define HGA_STATUS_VSYNC	0x80
  #define HGA_STATUS_VIDEO	0x08
  
  #define HGA_CONFIG_COL132	0x08
  #define HGA_GFX_MODE_EN		0x01
  #define HGA_GFX_PAGE_EN		0x02
  
  /* Global locks */
  
  static DEFINE_SPINLOCK(hga_reg_lock);
  
  /* Framebuffer driver structures */

  static struct fb_var_screeninfo hga_default_var __devinitdata = {

  	.xres		= 720,
  	.yres 		= 348,
  	.xres_virtual 	= 720,
  	.yres_virtual	= 348,
  	.bits_per_pixel = 1,
  	.red 		= {0, 1, 0},
  	.green 		= {0, 1, 0},
  	.blue 		= {0, 1, 0},
  	.transp 	= {0, 0, 0},
  	.height 	= -1,
  	.width 		= -1,
  };

  static struct fb_fix_screeninfo hga_fix __devinitdata = {

  	.id 		= "HGA",
  	.type 		= FB_TYPE_PACKED_PIXELS,	/* (not sure) */
  	.visual 	= FB_VISUAL_MONO10,
  	.xpanstep 	= 8,
  	.ypanstep 	= 8,
  	.line_length 	= 90,
  	.accel 		= FB_ACCEL_NONE
  };

  /* Don't assume that tty1 will be the initial current console. */
  static int release_io_port = 0;
  static int release_io_ports = 0;

  static bool nologo = 0;

  
  /* -------------------------------------------------------------------------
   *
   * Low level hardware functions
   *
   * ------------------------------------------------------------------------- */
  
  static void write_hga_b(unsigned int val, unsigned char reg)
  {
  	outb_p(reg, HGA_INDEX_PORT); 
  	outb_p(val, HGA_VALUE_PORT);
  }
  
  static void write_hga_w(unsigned int val, unsigned char reg)
  {
  	outb_p(reg,   HGA_INDEX_PORT); outb_p(val >> 8,   HGA_VALUE_PORT);
  	outb_p(reg+1, HGA_INDEX_PORT); outb_p(val & 0xff, HGA_VALUE_PORT);
  }
  
  static int test_hga_b(unsigned char val, unsigned char reg)
  {
  	outb_p(reg, HGA_INDEX_PORT); 
  	outb  (val, HGA_VALUE_PORT);
  	udelay(20); val = (inb_p(HGA_VALUE_PORT) == val);
  	return val;
  }
  
  static void hga_clear_screen(void)
  {
  	unsigned char fillchar = 0xbf; /* magic */
  	unsigned long flags;
  
  	spin_lock_irqsave(&hga_reg_lock, flags);
  	if (hga_mode == HGA_TXT)
  		fillchar = ' ';
  	else if (hga_mode == HGA_GFX)
  		fillchar = 0x00;
  	spin_unlock_irqrestore(&hga_reg_lock, flags);
  	if (fillchar != 0xbf)
  		memset_io(hga_vram, fillchar, hga_vram_len);
  }
  
  static void hga_txt_mode(void)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&hga_reg_lock, flags);
  	outb_p(HGA_MODE_VIDEO_EN | HGA_MODE_BLINK_EN, HGA_MODE_PORT);
  	outb_p(0x00, HGA_GFX_PORT);
  	outb_p(0x00, HGA_STATUS_PORT);
  
  	write_hga_b(0x61, 0x00);	/* horizontal total */
  	write_hga_b(0x50, 0x01);	/* horizontal displayed */
  	write_hga_b(0x52, 0x02);	/* horizontal sync pos */
  	write_hga_b(0x0f, 0x03);	/* horizontal sync width */
  
  	write_hga_b(0x19, 0x04);	/* vertical total */
  	write_hga_b(0x06, 0x05);	/* vertical total adjust */
  	write_hga_b(0x19, 0x06);	/* vertical displayed */
  	write_hga_b(0x19, 0x07);	/* vertical sync pos */
  
  	write_hga_b(0x02, 0x08);	/* interlace mode */
  	write_hga_b(0x0d, 0x09);	/* maximum scanline */
  	write_hga_b(0x0c, 0x0a);	/* cursor start */
  	write_hga_b(0x0d, 0x0b);	/* cursor end */
  
  	write_hga_w(0x0000, 0x0c);	/* start address */
  	write_hga_w(0x0000, 0x0e);	/* cursor location */
  
  	hga_mode = HGA_TXT;
  	spin_unlock_irqrestore(&hga_reg_lock, flags);
  }
  
  static void hga_gfx_mode(void)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&hga_reg_lock, flags);
  	outb_p(0x00, HGA_STATUS_PORT);
  	outb_p(HGA_GFX_MODE_EN, HGA_GFX_PORT);
  	outb_p(HGA_MODE_VIDEO_EN | HGA_MODE_GRAPHICS, HGA_MODE_PORT);
  
  	write_hga_b(0x35, 0x00);	/* horizontal total */
  	write_hga_b(0x2d, 0x01);	/* horizontal displayed */
  	write_hga_b(0x2e, 0x02);	/* horizontal sync pos */
  	write_hga_b(0x07, 0x03);	/* horizontal sync width */
  
  	write_hga_b(0x5b, 0x04);	/* vertical total */
  	write_hga_b(0x02, 0x05);	/* vertical total adjust */
  	write_hga_b(0x57, 0x06);	/* vertical displayed */
  	write_hga_b(0x57, 0x07);	/* vertical sync pos */
  
  	write_hga_b(0x02, 0x08);	/* interlace mode */
  	write_hga_b(0x03, 0x09);	/* maximum scanline */
  	write_hga_b(0x00, 0x0a);	/* cursor start */
  	write_hga_b(0x00, 0x0b);	/* cursor end */
  
  	write_hga_w(0x0000, 0x0c);	/* start address */
  	write_hga_w(0x0000, 0x0e);	/* cursor location */
  
  	hga_mode = HGA_GFX;
  	spin_unlock_irqrestore(&hga_reg_lock, flags);
  }
  
  static void hga_show_logo(struct fb_info *info)
  {
  /*
  	void __iomem *dest = hga_vram;
  	char *logo = linux_logo_bw;
  	int x, y;
  	
  	for (y = 134; y < 134 + 80 ; y++) * this needs some cleanup *
  		for (x = 0; x < 10 ; x++)
  			writeb(~*(logo++),(dest + HGA_ROWADDR(y) + x + 40));
  */
  }
  
  static void hga_pan(unsigned int xoffset, unsigned int yoffset)
  {
  	unsigned int base;
  	unsigned long flags;
  	
  	base = (yoffset / 8) * 90 + xoffset;
  	spin_lock_irqsave(&hga_reg_lock, flags);
  	write_hga_w(base, 0x0c);	/* start address */
  	spin_unlock_irqrestore(&hga_reg_lock, flags);
  	DPRINTK("hga_pan: base:%d
  ", base);
  }
  
  static void hga_blank(int blank_mode)
  {
  	unsigned long flags;
  
  	spin_lock_irqsave(&hga_reg_lock, flags);
  	if (blank_mode) {
  		outb_p(0x00, HGA_MODE_PORT);	/* disable video */
  	} else {
  		outb_p(HGA_MODE_VIDEO_EN | HGA_MODE_GRAPHICS, HGA_MODE_PORT);
  	}
  	spin_unlock_irqrestore(&hga_reg_lock, flags);
  }

  static int __devinit hga_card_detect(void)

  {

  	int count = 0;

  	void __iomem *p, *q;
  	unsigned short p_save, q_save;
  
  	hga_vram_len  = 0x08000;
  
  	hga_vram = ioremap(0xb0000, hga_vram_len);
  
  	if (request_region(0x3b0, 12, "hgafb"))
  		release_io_ports = 1;
  	if (request_region(0x3bf, 1, "hgafb"))
  		release_io_port = 1;
  
  	/* do a memory check */
  
  	p = hga_vram;
  	q = hga_vram + 0x01000;
  
  	p_save = readw(p); q_save = readw(q);
  
  	writew(0xaa55, p); if (readw(p) == 0xaa55) count++;
  	writew(0x55aa, p); if (readw(p) == 0x55aa) count++;
  	writew(p_save, p);

  	if (count != 2)
  		goto error;

  
  	/* Ok, there is definitely a card registering at the correct
  	 * memory location, so now we do an I/O port test.
  	 */
  	

  	if (!test_hga_b(0x66, 0x0f))	    /* cursor low register */
  		goto error;
  
  	if (!test_hga_b(0x99, 0x0f))     /* cursor low register */
  		goto error;

  
  	/* 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(HGA_STATUS_PORT) & HGA_STATUS_VSYNC;
  
  	for (count=0; count < 50000 && p_save == q_save; count++) {
  		q_save = inb(HGA_STATUS_PORT) & HGA_STATUS_VSYNC;
  		udelay(2);
  	}
  
  	if (p_save == q_save) 

  		goto error;

  
  	switch (inb_p(HGA_STATUS_PORT) & 0x70) {
  		case 0x10:
  			hga_type = TYPE_HERCPLUS;
  			hga_type_name = "HerculesPlus";
  			break;
  		case 0x50:
  			hga_type = TYPE_HERCCOLOR;
  			hga_type_name = "HerculesColor";
  			break;
  		default:
  			hga_type = TYPE_HERC;
  			hga_type_name = "Hercules";
  			break;
  	}
  	return 1;

  error:
  	if (release_io_ports)
  		release_region(0x3b0, 12);
  	if (release_io_port)
  		release_region(0x3bf, 1);
  	return 0;

  }
  
  /**
   *	hgafb_open - open the framebuffer device
   *	@info:pointer to fb_info object containing info for current hga board
   *	@int:open by console system or userland.
   */
  
  static int hgafb_open(struct fb_info *info, int init)
  {
  	hga_gfx_mode();
  	hga_clear_screen();
  	if (!nologo) hga_show_logo(info);
  	return 0;
  }
  
  /**
   *	hgafb_open - open the framebuffer device
   *	@info:pointer to fb_info object containing info for current hga board
   *	@int:open by console system or userland.
   */
  
  static int hgafb_release(struct fb_info *info, int init)
  {
  	hga_txt_mode();
  	hga_clear_screen();
  	return 0;
  }
  
  /**
   *	hgafb_setcolreg - set color registers
   *	@regno:register index to set
   *	@red:red value, unused
   *	@green:green value, unused
   *	@blue:blue value, unused
   *	@transp:transparency value, unused
   *	@info:unused
   *
   *	This callback function is used to set the color registers of a HGA
   *	board. Since we have only two fixed colors only @regno is checked.
   *	A zero is returned on success and 1 for failure.
   */
  
  static int hgafb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
  			   u_int transp, struct fb_info *info)
  {
  	if (regno > 1)
  		return 1;
  	return 0;
  }
  
  /**
   *	hga_pan_display - pan or wrap the display
   *	@var:contains new xoffset, yoffset and vmode values
   *	@info:pointer to fb_info object containing info for current hga board
   *
   *	This function looks only at xoffset, yoffset and the %FB_VMODE_YWRAP
   *	flag in @var. If input parameters are correct it calls hga_pan() to 
   *	program the hardware. @info->var is updated to the new values.
   *	A zero is returned on success and %-EINVAL for failure.
   */
  
  static int hgafb_pan_display(struct fb_var_screeninfo *var,
  			     struct fb_info *info)
  {
  	if (var->vmode & FB_VMODE_YWRAP) {
  		if (var->yoffset < 0 || 
  		    var->yoffset >= info->var.yres_virtual ||
  		    var->xoffset)
  			return -EINVAL;
  	} else {

  		if (var->xoffset + info->var.xres > info->var.xres_virtual
  		 || var->yoffset + info->var.yres > info->var.yres_virtual

  		 || var->yoffset % 8)
  			return -EINVAL;
  	}
  
  	hga_pan(var->xoffset, var->yoffset);
  	return 0;
  }
  
  /**
   *	hgafb_blank - (un)blank the screen
   *	@blank_mode:blanking method to use
   *	@info:unused
   *	
   *	Blank the screen if blank_mode != 0, else unblank. 
   *	Implements VESA suspend and powerdown modes on hardware that supports 
   *	disabling hsync/vsync:
   *		@blank_mode == 2 means suspend vsync,
   *		@blank_mode == 3 means suspend hsync,
   *		@blank_mode == 4 means powerdown.
   */
  
  static int hgafb_blank(int blank_mode, struct fb_info *info)
  {
  	hga_blank(blank_mode);
  	return 0;
  }
  
  /*
   * Accel functions
   */

  static void hgafb_fillrect(struct fb_info *info, const struct fb_fillrect *rect)
  {
  	u_int rows, y;
  	u8 __iomem *dest;
  
  	y = rect->dy;
  
  	for (rows = rect->height; rows--; y++) {
  		dest = rowaddr(info, y) + (rect->dx >> 3);
  		switch (rect->rop) {
  		case ROP_COPY:

  			memset_io(dest, rect->color, (rect->width >> 3));

  			break;
  		case ROP_XOR:
  			fb_writeb(~(fb_readb(dest)), dest);
  			break;
  		}
  	}
  }
  
  static void hgafb_copyarea(struct fb_info *info, const struct fb_copyarea *area)
  {
  	u_int rows, y1, y2;
  	u8 __iomem *src;
  	u8 __iomem *dest;
  
  	if (area->dy <= area->sy) {
  		y1 = area->sy;
  		y2 = area->dy;
  
  		for (rows = area->height; rows--; ) {
  			src = rowaddr(info, y1) + (area->sx >> 3);
  			dest = rowaddr(info, y2) + (area->dx >> 3);

  			memmove(dest, src, (area->width >> 3));

  			y1++;
  			y2++;
  		}
  	} else {
  		y1 = area->sy + area->height - 1;
  		y2 = area->dy + area->height - 1;
  
  		for (rows = area->height; rows--;) {
  			src = rowaddr(info, y1) + (area->sx >> 3);
  			dest = rowaddr(info, y2) + (area->dx >> 3);

  			memmove(dest, src, (area->width >> 3));

  			y1--;
  			y2--;
  		}
  	}
  }
  
  static void hgafb_imageblit(struct fb_info *info, const struct fb_image *image)
  {
  	u8 __iomem *dest;
  	u8 *cdat = (u8 *) image->data;
  	u_int rows, y = image->dy;

  	u_int x;

  	u8 d;
  
  	for (rows = image->height; rows--; y++) {

  		for (x = 0; x < image->width; x+= 8) {
  			d = *cdat++;
  			dest = rowaddr(info, y) + ((image->dx + x)>> 3);
  			fb_writeb(d, dest);
  		}

  	}
  }

  
  static struct fb_ops hgafb_ops = {
  	.owner		= THIS_MODULE,
  	.fb_open	= hgafb_open,
  	.fb_release	= hgafb_release,
  	.fb_setcolreg	= hgafb_setcolreg,
  	.fb_pan_display	= hgafb_pan_display,
  	.fb_blank	= hgafb_blank,
  	.fb_fillrect	= hgafb_fillrect,
  	.fb_copyarea	= hgafb_copyarea,
  	.fb_imageblit	= hgafb_imageblit,
  };
  		
  /* ------------------------------------------------------------------------- *
   *
   * Functions in fb_info
   * 
   * ------------------------------------------------------------------------- */
  
  /* ------------------------------------------------------------------------- */
      
  	/*
  	 *  Initialization
  	 */

  static int __devinit hgafb_probe(struct platform_device *pdev)

  {

  	struct fb_info *info;

  
  	if (! hga_card_detect()) {
  		printk(KERN_INFO "hgafb: HGA card not detected.
  ");
  		if (hga_vram)
  			iounmap(hga_vram);
  		return -EINVAL;
  	}
  
  	printk(KERN_INFO "hgafb: %s with %ldK of memory detected.
  ",
  		hga_type_name, hga_vram_len/1024);

  	info = framebuffer_alloc(0, &pdev->dev);

  	if (!info) {
  		iounmap(hga_vram);
  		return -ENOMEM;
  	}

  	hga_fix.smem_start = (unsigned long)hga_vram;
  	hga_fix.smem_len = hga_vram_len;

  	info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN;
  	info->var = hga_default_var;
  	info->fix = hga_fix;
  	info->monspecs.hfmin = 0;
  	info->monspecs.hfmax = 0;
  	info->monspecs.vfmin = 10000;
  	info->monspecs.vfmax = 10000;
  	info->monspecs.dpms = 0;
  	info->fbops = &hgafb_ops;
  	info->screen_base = hga_vram;
  
          if (register_framebuffer(info) < 0) {
  		framebuffer_release(info);

  		iounmap(hga_vram);
  		return -EINVAL;
  	}
  
          printk(KERN_INFO "fb%d: %s frame buffer device
  ",

                 info->node, info->fix.id);

  	platform_set_drvdata(pdev, info);

  	return 0;
  }

  static int __devexit hgafb_remove(struct platform_device *pdev)

  {

  	struct fb_info *info = platform_get_drvdata(pdev);

  	hga_txt_mode();
  	hga_clear_screen();

  
  	if (info) {
  		unregister_framebuffer(info);
  		framebuffer_release(info);
  	}

  	iounmap(hga_vram);

  
  	if (release_io_ports)
  		release_region(0x3b0, 12);
  
  	if (release_io_port)
  		release_region(0x3bf, 1);
  
  	return 0;
  }

  static struct platform_driver hgafb_driver = {

  	.probe = hgafb_probe,

  	.remove = __devexit_p(hgafb_remove),

  	.driver = {
  		.name = "hgafb",
  	},

  };

  static struct platform_device *hgafb_device;

  
  static int __init hgafb_init(void)
  {
  	int ret;
  
  	if (fb_get_options("hgafb", NULL))
  		return -ENODEV;

  	ret = platform_driver_register(&hgafb_driver);

  
  	if (!ret) {

  		hgafb_device = platform_device_register_simple("hgafb", 0, NULL, 0);
  
  		if (IS_ERR(hgafb_device)) {
  			platform_driver_unregister(&hgafb_driver);
  			ret = PTR_ERR(hgafb_device);
  		}

  	}
  
  	return ret;
  }
  
  static void __exit hgafb_exit(void)
  {

  	platform_device_unregister(hgafb_device);
  	platform_driver_unregister(&hgafb_driver);

  }

  
  /* -------------------------------------------------------------------------
   *
   *  Modularization
   *
   * ------------------------------------------------------------------------- */
  
  MODULE_AUTHOR("Ferenc Bakonyi (fero@drama.obuda.kando.hu)");
  MODULE_DESCRIPTION("FBDev driver for Hercules Graphics Adaptor");
  MODULE_LICENSE("GPL");
  
  module_param(nologo, bool, 0);
  MODULE_PARM_DESC(nologo, "Disables startup logo if != 0 (default=0)");
  module_init(hgafb_init);

  module_exit(hgafb_exit);