/* -*- linux-c -*- ------------------------------------------------------- *
   *
   *   Copyright (C) 1991, 1992 Linus Torvalds
   *   Copyright 2007 rPath, Inc. - All Rights Reserved
   *   Copyright 2009 Intel Corporation; author H. Peter Anvin
   *
   *   This file is part of the Linux kernel, and is made available under
   *   the terms of the GNU General Public License version 2.
   *
   * ----------------------------------------------------------------------- */
  
  /*
   * VESA text modes
   */
  
  #include "boot.h"
  #include "video.h"
  #include "vesa.h"
  
  /* VESA information */
  static struct vesa_general_info vginfo;
  static struct vesa_mode_info vminfo;
  
  static __videocard video_vesa;
  
  #ifndef _WAKEUP
  static void vesa_store_mode_params_graphics(void);
  #else /* _WAKEUP */
  static inline void vesa_store_mode_params_graphics(void) {}
  #endif /* _WAKEUP */
  
  static int vesa_probe(void)
  {
  	struct biosregs ireg, oreg;
  	u16 mode;
  	addr_t mode_ptr;
  	struct mode_info *mi;
  	int nmodes = 0;
  
  	video_vesa.modes = GET_HEAP(struct mode_info, 0);
  
  	initregs(&ireg);
  	ireg.ax = 0x4f00;
  	ireg.di = (size_t)&vginfo;
  	intcall(0x10, &ireg, &oreg);
  
  	if (oreg.ax != 0x004f ||
  	    vginfo.signature != VESA_MAGIC ||
  	    vginfo.version < 0x0102)
  		return 0;	/* Not present */
  
  	set_fs(vginfo.video_mode_ptr.seg);
  	mode_ptr = vginfo.video_mode_ptr.off;
  
  	while ((mode = rdfs16(mode_ptr)) != 0xffff) {
  		mode_ptr += 2;
  
  		if (!heap_free(sizeof(struct mode_info)))
  			break;	/* Heap full, can't save mode info */
  
  		if (mode & ~0x1ff)
  			continue;
  
  		memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
  
  		ireg.ax = 0x4f01;
  		ireg.cx = mode;
  		ireg.di = (size_t)&vminfo;
  		intcall(0x10, &ireg, &oreg);
  
  		if (oreg.ax != 0x004f)
  			continue;
  
  		if ((vminfo.mode_attr & 0x15) == 0x05) {
  			/* Text Mode, TTY BIOS supported,
  			   supported by hardware */
  			mi = GET_HEAP(struct mode_info, 1);
  			mi->mode  = mode + VIDEO_FIRST_VESA;
  			mi->depth = 0; /* text */
  			mi->x     = vminfo.h_res;
  			mi->y     = vminfo.v_res;
  			nmodes++;
  		} else if ((vminfo.mode_attr & 0x99) == 0x99 &&
  			   (vminfo.memory_layout == 4 ||
  			    vminfo.memory_layout == 6) &&
  			   vminfo.memory_planes == 1) {
  #ifdef CONFIG_FB_BOOT_VESA_SUPPORT
  			/* Graphics mode, color, linear frame buffer
  			   supported.  Only register the mode if
  			   if framebuffer is configured, however,
  			   otherwise the user will be left without a screen. */
  			mi = GET_HEAP(struct mode_info, 1);
  			mi->mode = mode + VIDEO_FIRST_VESA;
  			mi->depth = vminfo.bpp;
  			mi->x = vminfo.h_res;
  			mi->y = vminfo.v_res;
  			nmodes++;
  #endif
  		}
  	}
  
  	return nmodes;
  }
  
  static int vesa_set_mode(struct mode_info *mode)
  {
  	struct biosregs ireg, oreg;
  	int is_graphic;
  	u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA;
  
  	memset(&vminfo, 0, sizeof vminfo); /* Just in case... */
  
  	initregs(&ireg);
  	ireg.ax = 0x4f01;
  	ireg.cx = vesa_mode;
  	ireg.di = (size_t)&vminfo;
  	intcall(0x10, &ireg, &oreg);
  
  	if (oreg.ax != 0x004f)
  		return -1;
  
  	if ((vminfo.mode_attr & 0x15) == 0x05) {
  		/* It's a supported text mode */
  		is_graphic = 0;
  #ifdef CONFIG_FB_BOOT_VESA_SUPPORT
  	} else if ((vminfo.mode_attr & 0x99) == 0x99) {
  		/* It's a graphics mode with linear frame buffer */
  		is_graphic = 1;
  		vesa_mode |= 0x4000; /* Request linear frame buffer */
  #endif
  	} else {
  		return -1;	/* Invalid mode */
  	}
  
  
  	initregs(&ireg);
  	ireg.ax = 0x4f02;
  	ireg.bx = vesa_mode;
  	intcall(0x10, &ireg, &oreg);
  
  	if (oreg.ax != 0x004f)
  		return -1;
  
  	graphic_mode = is_graphic;
  	if (!is_graphic) {
  		/* Text mode */
  		force_x = mode->x;
  		force_y = mode->y;
  		do_restore = 1;
  	} else {
  		/* Graphics mode */
  		vesa_store_mode_params_graphics();
  	}
  
  	return 0;
  }
  
  
  #ifndef _WAKEUP
  
  /* Switch DAC to 8-bit mode */
  static void vesa_dac_set_8bits(void)
  {
  	struct biosregs ireg, oreg;
  	u8 dac_size = 6;
  
  	/* If possible, switch the DAC to 8-bit mode */
  	if (vginfo.capabilities & 1) {
  		initregs(&ireg);
  		ireg.ax = 0x4f08;
  		ireg.bh = 0x08;
  		intcall(0x10, &ireg, &oreg);
  		if (oreg.ax == 0x004f)
  			dac_size = oreg.bh;
  	}
  
  	/* Set the color sizes to the DAC size, and offsets to 0 */
  	boot_params.screen_info.red_size   = dac_size;
  	boot_params.screen_info.green_size = dac_size;
  	boot_params.screen_info.blue_size  = dac_size;
  	boot_params.screen_info.rsvd_size  = dac_size;
  
  	boot_params.screen_info.red_pos    = 0;
  	boot_params.screen_info.green_pos  = 0;
  	boot_params.screen_info.blue_pos   = 0;
  	boot_params.screen_info.rsvd_pos   = 0;
  }
  
  /* Save the VESA protected mode info */
  static void vesa_store_pm_info(void)
  {
  	struct biosregs ireg, oreg;
  
  	initregs(&ireg);
  	ireg.ax = 0x4f0a;
  	intcall(0x10, &ireg, &oreg);
  
  	if (oreg.ax != 0x004f)
  		return;
  
  	boot_params.screen_info.vesapm_seg = oreg.es;
  	boot_params.screen_info.vesapm_off = oreg.di;
  }
  
  /*
   * Save video mode parameters for graphics mode
   */
  static void vesa_store_mode_params_graphics(void)
  {
  	/* Tell the kernel we're in VESA graphics mode */
  	boot_params.screen_info.orig_video_isVGA = VIDEO_TYPE_VLFB;
  
  	/* Mode parameters */
  	boot_params.screen_info.vesa_attributes = vminfo.mode_attr;
  	boot_params.screen_info.lfb_linelength = vminfo.logical_scan;
  	boot_params.screen_info.lfb_width = vminfo.h_res;
  	boot_params.screen_info.lfb_height = vminfo.v_res;
  	boot_params.screen_info.lfb_depth = vminfo.bpp;
  	boot_params.screen_info.pages = vminfo.image_planes;
  	boot_params.screen_info.lfb_base = vminfo.lfb_ptr;
  	memcpy(&boot_params.screen_info.red_size,
  	       &vminfo.rmask, 8);
  
  	/* General parameters */
  	boot_params.screen_info.lfb_size = vginfo.total_memory;
  
  	if (vminfo.bpp <= 8)
  		vesa_dac_set_8bits();
  
  	vesa_store_pm_info();
  }
  
  /*
   * Save EDID information for the kernel; this is invoked, separately,
   * after mode-setting.
   */
  void vesa_store_edid(void)
  {
  #ifdef CONFIG_FIRMWARE_EDID
  	struct biosregs ireg, oreg;
  
  	/* Apparently used as a nonsense token... */
  	memset(&boot_params.edid_info, 0x13, sizeof boot_params.edid_info);
  
  	if (vginfo.version < 0x0200)
  		return;		/* EDID requires VBE 2.0+ */
  
  	initregs(&ireg);
  	ireg.ax = 0x4f15;		/* VBE DDC */
  	/* ireg.bx = 0x0000; */		/* Report DDC capabilities */
  	/* ireg.cx = 0;	*/		/* Controller 0 */
  	ireg.es = 0;			/* ES:DI must be 0 by spec */
  	intcall(0x10, &ireg, &oreg);
  
  	if (oreg.ax != 0x004f)
  		return;		/* No EDID */
  
  	/* BH = time in seconds to transfer EDD information */
  	/* BL = DDC level supported */
  
  	ireg.ax = 0x4f15;		/* VBE DDC */
  	ireg.bx = 0x0001;		/* Read EDID */
  	/* ireg.cx = 0; */		/* Controller 0 */
  	/* ireg.dx = 0;	*/		/* EDID block number */
  	ireg.es = ds();
  	ireg.di =(size_t)&boot_params.edid_info; /* (ES:)Pointer to block */
  	intcall(0x10, &ireg, &oreg);
  #endif /* CONFIG_FIRMWARE_EDID */
  }
  
  #endif /* not _WAKEUP */
  
  static __videocard video_vesa =
  {
  	.card_name	= "VESA",
  	.probe		= vesa_probe,
  	.set_mode	= vesa_set_mode,
  	.xmode_first	= VIDEO_FIRST_VESA,
  	.xmode_n	= 0x200,
  };