vgacon.c

Linux环境下视频显示卡设备的驱动程序源代码

	outb_p(vga_state.CrtCtrlIndex, vga_video_port_reg);
	spin_unlock_irq(&vga_lock);
}

static void vga_vesa_unblank(struct vgastate *state)
{
	/* restore original values of VGA controller registers */
	spin_lock_irq(&vga_lock);
	vga_w(state->vgabase, VGA_MIS_W, vga_state.CrtMiscIO);

	outb_p(0x00, vga_video_port_reg);	/* HorizontalTotal */
	outb_p(vga_state.HorizontalTotal, vga_video_port_val);
	outb_p(0x01, vga_video_port_reg);	/* HorizDisplayEnd */
	outb_p(vga_state.HorizDisplayEnd, vga_video_port_val);
	outb_p(0x04, vga_video_port_reg);	/* StartHorizRetrace */
	outb_p(vga_state.StartHorizRetrace, vga_video_port_val);
	outb_p(0x05, vga_video_port_reg);	/* EndHorizRetrace */
	outb_p(vga_state.EndHorizRetrace, vga_video_port_val);
	outb_p(0x07, vga_video_port_reg);	/* Overflow */
	outb_p(vga_state.Overflow, vga_video_port_val);
	outb_p(0x10, vga_video_port_reg);	/* StartVertRetrace */
	outb_p(vga_state.StartVertRetrace, vga_video_port_val);
	outb_p(0x11, vga_video_port_reg);	/* EndVertRetrace */
	outb_p(vga_state.EndVertRetrace, vga_video_port_val);
	outb_p(0x17, vga_video_port_reg);	/* ModeControl */
	outb_p(vga_state.ModeControl, vga_video_port_val);
	/* ClockingMode */
	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, vga_state.ClockingMode);

	/* restore index/control registers */
	vga_w(state->vgabase, VGA_SEQ_I, vga_state.SeqCtrlIndex);
	outb_p(vga_state.CrtCtrlIndex, vga_video_port_reg);
	spin_unlock_irq(&vga_lock);
}

static void vga_pal_blank(struct vgastate *state)
{
	int i;

	vga_w(state->vgabase, VGA_PEL_MSK, 0xff);
	for (i = 0; i < 16; i++) {
		vga_w(state->vgabase, VGA_PEL_IW, i);
		vga_w(state->vgabase, VGA_PEL_D, 0);
		vga_w(state->vgabase, VGA_PEL_D, 0);
		vga_w(state->vgabase, VGA_PEL_D, 0);
	}
}

static int vgacon_blank(struct vc_data *c, int blank, int mode_switch)
{
	switch (blank) {
	case 0:		/* Unblank */
		if (vga_vesa_blanked) {
			vga_vesa_unblank(&state);
			vga_vesa_blanked = 0;
		}
		if (vga_palette_blanked) {
			vga_set_palette(c, color_table);
			vga_palette_blanked = 0;
			return 0;
		}
		vga_is_gfx = 0;
		/* Tell console.c that it has to restore the screen itself */
		return 1;
	case 1:		/* Normal blanking */
	case -1:	/* Obsolete */
		if (!mode_switch && vga_video_type == VIDEO_TYPE_VGAC) {
			vga_pal_blank(&state);
			vga_palette_blanked = 1;
			return 0;
		}
		vgacon_set_origin(c);
		scr_memsetw((void *) vga_vram_base, BLANK,
			    c->vc_screenbuf_size);
		if (mode_switch)
			vga_is_gfx = 1;
		return 1;
	default:		/* VESA blanking */
		if (vga_video_type == VIDEO_TYPE_VGAC) {
			vga_vesa_blank(&state, blank - 1);
			vga_vesa_blanked = blank;
		}
		return 0;
	}
}

/*
 * PIO_FONT support.
 *
 * The font loading code goes back to the codepage package by
 * Joel Hoffman ([e-mail]). (He reports that the original
 * reference is: "From: p. 307 of _Programmer's Guide to PC & PS/2
 * Video Systems_ by Richard Wilton. 1987.  Microsoft Press".)
 *
 * Change for certain monochrome monitors by Yury Shevchuck
 * ([e-mail]).
 */

#ifdef CAN_LOAD_EGA_FONTS

#define colourmap 0xa0000
/* Pauline Middelink <[e-mail]> reports that we
   should use 0xA0000 for the bwmap as well.. */
#define blackwmap 0xa0000
#define cmapsz 8192

static int vgacon_do_font_op(struct vgastate *state,char *arg,int set,int ch512)
{
	unsigned short video_port_status = vga_video_port_reg + 6;
	int font_select = 0x00, beg, i;
	char *charmap;
	
	if (vga_video_type != VIDEO_TYPE_EGAM) {
		charmap = (char *) VGA_MAP_MEM(colourmap, 0);
		beg = 0x0e;
#ifdef VGA_CAN_DO_64KB
		if (vga_video_type == VIDEO_TYPE_VGAC)
			beg = 0x06;
#endif
	} else {
		charmap = (char *) VGA_MAP_MEM(blackwmap, 0);
		beg = 0x0a;
	}

#ifdef BROKEN_GRAPHICS_PROGRAMS
	/*
	 * All fonts are loaded in slot 0 (0:1 for 512 ch)
	 */

	if (!arg)
		return -EINVAL;	/* Return to default font not supported */

	vga_font_is_default = 0;
	font_select = ch512 ? 0x04 : 0x00;
#else
	/*
	 * The default font is kept in slot 0 and is never touched.
	 * A custom font is loaded in slot 2 (256 ch) or 2:3 (512 ch)
	 */

	if (set) {
		vga_font_is_default = !arg;
		if (!arg)
			ch512 = 0;	/* Default font is always 256 */
		font_select = arg ? (ch512 ? 0x0e : 0x0a) : 0x00;
	}

	if (!vga_font_is_default)
		charmap += 4 * cmapsz;
#endif

	unlock_kernel();
	spin_lock_irq(&vga_lock);
	/* First, the Sequencer */
	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
	/* CPU writes only to map 2 */
	vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x04);	
	/* Sequential addressing */
	vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x07);	
	/* Clear synchronous reset */
	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x03);

	/* Now, the graphics controller, select map 2 */
	vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x02);		
	/* disable odd-even addressing */
	vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x00);
	/* map start at A000:0000 */
	vga_wgfx(state->vgabase, VGA_GFX_MISC, 0x00);
	spin_unlock_irq(&vga_lock);

	if (arg) {
		if (set)
			for (i = 0; i < cmapsz; i++)
				vga_writeb(arg[i], charmap + i);
		else
			for (i = 0; i < cmapsz; i++)
				arg[i] = vga_readb(charmap + i);

		/*
		 * In 512-character mode, the character map is not contiguous if
		 * we want to remain EGA compatible -- which we do
		 */

		if (ch512) {
			charmap += 2 * cmapsz;
			arg += cmapsz;
			if (set)
				for (i = 0; i < cmapsz; i++)
					vga_writeb(arg[i], charmap + i);
			else
				for (i = 0; i < cmapsz; i++)
					arg[i] = vga_readb(charmap + i);
		}
	}

	spin_lock_irq(&vga_lock);
	/* First, the sequencer, Synchronous reset */
	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x01);	
	/* CPU writes to maps 0 and 1 */
	vga_wseq(state->vgabase, VGA_SEQ_PLANE_WRITE, 0x03);
	/* odd-even addressing */
	vga_wseq(state->vgabase, VGA_SEQ_MEMORY_MODE, 0x03);
	/* Character Map Select */
	if (set)
		vga_wseq(state->vgabase, VGA_SEQ_CHARACTER_MAP, font_select);
	/* clear synchronous reset */
	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x03);

	/* Now, the graphics controller, select map 0 for CPU */
	vga_wgfx(state->vgabase, VGA_GFX_PLANE_READ, 0x00);
	/* enable even-odd addressing */
	vga_wgfx(state->vgabase, VGA_GFX_MODE, 0x10);
	/* map starts at b800:0 or b000:0 */
	vga_wgfx(state->vgabase, VGA_GFX_MISC, beg);

	/* if 512 char mode is already enabled don't re-enable it. */
	if ((set) && (ch512 != vga_512_chars)) {
		/* attribute controller */
		for (i = 0; i < MAX_NR_CONSOLES; i++) {
			struct vc_data *c = vc_cons[i].d;
			if (c && c->vc_sw == &vga_con)
				c->vc_hi_font_mask = ch512 ? 0x0800 : 0;
		}
		vga_512_chars = ch512;
		/* 256-char: enable intensity bit
		   512-char: disable intensity bit */
		inb_p(video_port_status);	/* clear address flip-flop */
		/* color plane enable register */
		vga_wattr(state->vgabase, VGA_ATC_PLANE_ENABLE, ch512 ? 0x07 : 0x0f);
		/* Wilton (1987) mentions the following; I don't know what
		   it means, but it works, and it appears necessary */
		inb_p(video_port_status);
		vga_wattr(state->vgabase, VGA_AR_ENABLE_DISPLAY, 0);	
	}
	spin_unlock_irq(&vga_lock);
	lock_kernel();
	return 0;
}

/*
 * Adjust the screen to fit a font of a certain height
 */
static int vgacon_adjust_height(struct vc_data *vc, unsigned fontheight)
{
	unsigned char ovr, vde, fsr;
	int rows, maxscan, i;

	rows = vc->vc_scan_lines / fontheight;	/* Number of video rows we end up with */
	maxscan = rows * fontheight - 1;	/* Scan lines to actually display-1 */

	/* Reprogram the CRTC for the new font size
	   Note: the attempt to read the overflow register will fail
	   on an EGA, but using 0xff for the previous value appears to
	   be OK for EGA text modes in the range 257-512 scan lines, so I
	   guess we don't need to worry about it.

	   The same applies for the spill bits in the font size and cursor
	   registers; they are write-only on EGA, but it appears that they
	   are all don't care bits on EGA, so I guess it doesn't matter. */

	spin_lock_irq(&vga_lock);
	outb_p(0x07, vga_video_port_reg);	/* CRTC overflow register */
	ovr = inb_p(vga_video_port_val);
	outb_p(0x09, vga_video_port_reg);	/* Font size register */
	fsr = inb_p(vga_video_port_val);
	spin_unlock_irq(&vga_lock);

	vde = maxscan & 0xff;	/* Vertical display end reg */
	ovr = (ovr & 0xbd) +	/* Overflow register */
	    ((maxscan & 0x100) >> 7) + ((maxscan & 0x200) >> 3);
	fsr = (fsr & 0xe0) + (fontheight - 1);	/*  Font size register */

	spin_lock_irq(&vga_lock);
	outb_p(0x07, vga_video_port_reg);	/* CRTC overflow register */
	outb_p(ovr, vga_video_port_val);
	outb_p(0x09, vga_video_port_reg);	/* Font size */
	outb_p(fsr, vga_video_port_val);
	outb_p(0x12, vga_video_port_reg);	/* Vertical display limit */
	outb_p(vde, vga_video_port_val);
	spin_unlock_irq(&vga_lock);
	vga_video_font_height = fontheight;

	for (i = 0; i < MAX_NR_CONSOLES; i++) {
		struct vc_data *c = vc_cons[i].d;

		if (c && c->vc_sw == &vga_con) {
			if (CON_IS_VISIBLE(c)) {
			        /* void size to cause regs to be rewritten */
				cursor_size_lastfrom = 0;
				cursor_size_lastto = 0;
				c->vc_sw->con_cursor(c, CM_DRAW);
			}
			c->vc_font.height = fontheight;
			vc_resize(c, 0, rows);	/* Adjust console size */
		}
	}
	return 0;
}

static int vgacon_font_set(struct vc_data *c, struct console_font *font, unsigned flags)
{
	unsigned charcount = font->charcount;
	int rc;

	if (vga_video_type < VIDEO_TYPE_EGAM)
		return -EINVAL;

	if (font->width != VGA_FONTWIDTH ||
	    (charcount != 256 && charcount != 512))
		return -EINVAL;

	rc = vgacon_do_font_op(&state, font->data, 1, charcount == 512);
	if (rc)
		return rc;

	if (!(flags & KD_FONT_FLAG_DONT_RECALC))
		rc = vgacon_adjust_height(c, font->height);
	return rc;
}

static int vgacon_font_get(struct vc_data *c, struct console_font *font)
{
	if (vga_video_type < VIDEO_TYPE_EGAM)
		return -EINVAL;

	font->width = VGA_FONTWIDTH;
	font->height = c->vc_font.height;
	font->charcount = vga_512_chars ? 512 : 256;
	if (!font->data)
		return 0;
	return vgacon_do_font_op(&state, font->data, 0, 0);
}

#else

#define vgacon_font_set NULL
#define vgacon_font_get NULL

#endif

static int vgacon_resize(struct vc_data *c, unsigned int width,
			 unsigned int height, unsigned int user)
{
	if (width % 2 || width > screen_info.orig_video_cols ||
	    height > (screen_info.orig_video_lines * vga_default_font_height)/
	    c->vc_font.height)
		/* let svgatextmode tinker with video timings and
		   return success */
		return (user) ? 0 : -EINVAL;

	if (CON_IS_VISIBLE(c) && !vga_is_gfx) /* who knows */
		vgacon_doresize(c, width, height);
	return 0;
}

static int vgacon_set_origin(struct vc_data *c)
{
	if (vga_is_gfx ||	/* We don't play origin tricks in graphic modes */
	    (console_blanked && !vga_palette_blanked))	/* Nor we write to blanked screens */
		return 0;
	c->vc_origin = c->vc_visible_origin = vga_vram_base;
	vga_set_mem_top(c);
	vga_rolled_over = 0;
	return 1;
}

static void vgacon_save_screen(struct vc_data *c)
{
	static int vga_bootup_console = 0;

	if (!vga_bootup_console) {
		/* This is a gross hack, but here is the only place we can
		 * set bootup console parameters without messing up generic
		 * console initialization routines.
		 */
		vga_bootup_console = 1;
		c->vc_x = screen_info.orig_x;
		c->vc_y = screen_info.orig_y;
	}

	/* We can't copy in more than the size of the video buffer,
	 * or we'll be copying in VGA BIOS */

	if (!vga_is_gfx)
		scr_memcpyw((u16 *) c->vc_screenbuf, (u16 *) c->vc_origin,
			    c->vc_screenbuf_size > vga_vram_size ? vga_vram_size : c->vc_screenbuf_size);
}

static int vgacon_scroll(struct vc_data *c, int t, int b, int dir,
			 int lines)
{
	unsigned long oldo;
	unsigned int delta;

	if (t || b != c->vc_rows || vga_is_gfx || c->vc_mode != KD_TEXT)
		return 0;

	if (!vga_hardscroll_enabled || lines >= c->vc_rows / 2)
		return 0;

	vgacon_restore_screen(c);
	oldo = c->vc_origin;
	delta = lines * c->vc_size_row;
	if (dir == SM_UP) {
		vgacon_scrollback_update(c, t, lines);
		if (c->vc_scr_end + delta >= vga_vram_end) {
			scr_memcpyw((u16 *) vga_vram_base,
				    (u16 *) (oldo + delta),
				    c->vc_screenbuf_size - delta);
			c->vc_origin = vga_vram_base;
			vga_rolled_over = oldo - vga_vram_base;
		} else
			c->vc_origin += delta;
		scr_memsetw((u16 *) (c->vc_origin + c->vc_screenbuf_size -
				     delta), c->vc_video_erase_char,
			    delta);
	} else {
		if (oldo - delta < vga_vram_base) {
			scr_memmovew((u16 *) (vga_vram_end -
					      c->vc_screenbuf_size +
					      delta), (u16 *) oldo,
				     c->vc_screenbuf_size - delta);
			c->vc_origin = vga_vram_end - c->vc_screenbuf_size;
			vga_rolled_over = 0;
		} else
			c->vc_origin -= delta;
		c->vc_scr_end = c->vc_origin + c->vc_screenbuf_size;
		scr_memsetw((u16 *) (c->vc_origin), c->vc_video_erase_char,
			    delta);
	}
	c->vc_scr_end = c->vc_origin + c->vc_screenbuf_size;
	c->vc_visible_origin = c->vc_origin;
	vga_set_mem_top(c);
	c->vc_pos = (c->vc_pos - oldo) + c->vc_origin;
	return 1;
}


/*
 *  The console `switch' structure for the VGA based console
 */

static int vgacon_dummy(struct vc_data *c)
{
	return 0;
}

#define DUMMY (void *) vgacon_dummy

const struct consw vga_con = {
	.owner = THIS_MODULE,
	.con_startup = vgacon_startup,
	.con_init = vgacon_init,
	.con_deinit = vgacon_deinit,
	.con_clear = DUMMY,
	.con_putc = DUMMY,
	.con_putcs = DUMMY,
	.con_cursor = vgacon_cursor,
	.con_scroll = vgacon_scroll,
	.con_bmove = DUMMY,
	.con_switch = vgacon_switch,
	.con_blank = vgacon_blank,
	.con_font_set = vgacon_font_set,
	.con_font_get = vgacon_font_get,
	.con_resize = vgacon_resize,
	.con_set_palette = vgacon_set_palette,
	.con_scrolldelta = vgacon_scrolldelta,
	.con_set_origin = vgacon_set_origin,
	.con_save_screen = vgacon_save_screen,
	.con_build_attr = vgacon_build_attr,
	.con_invert_region = vgacon_invert_region,
};

MODULE_LICENSE("GPL");