vgacon.c

Linux环境下视频显示卡设备的驱动程序源代码

				 */

				for (i = 0; i < 16; i++) {
					inb_p(VGA_IS1_RC);
					outb_p(i, VGA_ATT_W);
					outb_p(i, VGA_ATT_W);
				}
				outb_p(0x20, VGA_ATT_W);

				/*
				 * Now set the DAC registers back to their
				 * default values
				 */
				for (i = 0; i < 16; i++) {
					outb_p(color_table[i], VGA_PEL_IW);
					outb_p(default_red[i], VGA_PEL_D);
					outb_p(default_grn[i], VGA_PEL_D);
					outb_p(default_blu[i], VGA_PEL_D);
				}
			}
		} else {
			static struct resource cga_console_resource =
			    { .name = "cga", .start = 0x3D4, .end = 0x3D5 };
			vga_video_type = VIDEO_TYPE_CGA;
			vga_vram_size = 0x2000;
			display_desc = "*CGA";
			request_resource(&ioport_resource,
					 &cga_console_resource);
			vga_video_font_height = 8;
		}
	}

	vga_vram_base = VGA_MAP_MEM(vga_vram_base, vga_vram_size);
	vga_vram_end = vga_vram_base + vga_vram_size;

	/*
	 *      Find out if there is a graphics card present.
	 *      Are there smarter methods around?
	 */
	p = (volatile u16 *) vga_vram_base;
	saved1 = scr_readw(p);
	saved2 = scr_readw(p + 1);
	scr_writew(0xAA55, p);
	scr_writew(0x55AA, p + 1);
	if (scr_readw(p) != 0xAA55 || scr_readw(p + 1) != 0x55AA) {
		scr_writew(saved1, p);
		scr_writew(saved2, p + 1);
		goto no_vga;
	}
	scr_writew(0x55AA, p);
	scr_writew(0xAA55, p + 1);
	if (scr_readw(p) != 0x55AA || scr_readw(p + 1) != 0xAA55) {
		scr_writew(saved1, p);
		scr_writew(saved2, p + 1);
		goto no_vga;
	}
	scr_writew(saved1, p);
	scr_writew(saved2, p + 1);

	if (vga_video_type == VIDEO_TYPE_EGAC
	    || vga_video_type == VIDEO_TYPE_VGAC
	    || vga_video_type == VIDEO_TYPE_EGAM) {
		vga_hardscroll_enabled = vga_hardscroll_user_enable;
		vga_default_font_height = screen_info.orig_video_points;
		vga_video_font_height = screen_info.orig_video_points;
		/* This may be suboptimal but is a safe bet - go with it */
		vga_scan_lines =
		    vga_video_font_height * vga_video_num_lines;
	}

	vgacon_xres = screen_info.orig_video_cols * VGA_FONTWIDTH;
	vgacon_yres = vga_scan_lines;

	if (!vga_init_done) {
		vgacon_scrollback_startup();
		vga_init_done = 1;
	}

	return display_desc;
}

static void vgacon_init(struct vc_data *c, int init)
{
	unsigned long p;

	/*
	 * We cannot be loaded as a module, therefore init is always 1,
	 * but vgacon_init can be called more than once, and init will
	 * not be 1.
	 */
	c->vc_can_do_color = vga_can_do_color;

	/* set dimensions manually if init != 0 since vc_resize() will fail */
	if (init) {
		c->vc_cols = vga_video_num_columns;
		c->vc_rows = vga_video_num_lines;
	} else
		vc_resize(c, vga_video_num_columns, vga_video_num_lines);

	c->vc_scan_lines = vga_scan_lines;
	c->vc_font.height = vga_video_font_height;
	c->vc_complement_mask = 0x7700;
	if (vga_512_chars)
		c->vc_hi_font_mask = 0x0800;
	p = *c->vc_uni_pagedir_loc;
	if (c->vc_uni_pagedir_loc == &c->vc_uni_pagedir ||
	    !--c->vc_uni_pagedir_loc[1])
		con_free_unimap(c);
	c->vc_uni_pagedir_loc = vgacon_uni_pagedir;
	vgacon_uni_pagedir[1]++;
	if (!vgacon_uni_pagedir[0] && p)
		con_set_default_unimap(c);
}

static void vgacon_deinit(struct vc_data *c)
{
	/* When closing the last console, reset video origin */
	if (!--vgacon_uni_pagedir[1]) {
		c->vc_visible_origin = vga_vram_base;
		vga_set_mem_top(c);
		con_free_unimap(c);
	}
	c->vc_uni_pagedir_loc = &c->vc_uni_pagedir;
	con_set_default_unimap(c);
}

static u8 vgacon_build_attr(struct vc_data *c, u8 color, u8 intensity,
			    u8 blink, u8 underline, u8 reverse, u8 italic)
{
	u8 attr = color;

	if (vga_can_do_color) {
		if (italic)
			attr = (attr & 0xF0) | c->vc_itcolor;
		else if (underline)
			attr = (attr & 0xf0) | c->vc_ulcolor;
		else if (intensity == 0)
			attr = (attr & 0xf0) | c->vc_halfcolor;
	}
	if (reverse)
		attr =
		    ((attr) & 0x88) | ((((attr) >> 4) | ((attr) << 4)) &
				       0x77);
	if (blink)
		attr ^= 0x80;
	if (intensity == 2)
		attr ^= 0x08;
	if (!vga_can_do_color) {
		if (italic)
			attr = (attr & 0xF8) | 0x02;
		else if (underline)
			attr = (attr & 0xf8) | 0x01;
		else if (intensity == 0)
			attr = (attr & 0xf0) | 0x08;
	}
	return attr;
}

static void vgacon_invert_region(struct vc_data *c, u16 * p, int count)
{
	int col = vga_can_do_color;

	while (count--) {
		u16 a = scr_readw(p);
		if (col)
			a = ((a) & 0x88ff) | (((a) & 0x7000) >> 4) |
			    (((a) & 0x0700) << 4);
		else
			a ^= ((a & 0x0700) == 0x0100) ? 0x7000 : 0x7700;
		scr_writew(a, p++);
	}
}

static void vgacon_set_cursor_size(int xpos, int from, int to)
{
	unsigned long flags;
	int curs, cure;

#ifdef TRIDENT_GLITCH
	if (xpos < 16)
		from--, to--;
#endif

	if ((from == cursor_size_lastfrom) && (to == cursor_size_lastto))
		return;
	cursor_size_lastfrom = from;
	cursor_size_lastto = to;

	spin_lock_irqsave(&vga_lock, flags);
	if (vga_video_type >= VIDEO_TYPE_VGAC) {
		outb_p(VGA_CRTC_CURSOR_START, vga_video_port_reg);
		curs = inb_p(vga_video_port_val);
		outb_p(VGA_CRTC_CURSOR_END, vga_video_port_reg);
		cure = inb_p(vga_video_port_val);
	} else {
		curs = 0;
		cure = 0;
	}

	curs = (curs & 0xc0) | from;
	cure = (cure & 0xe0) | to;

	outb_p(VGA_CRTC_CURSOR_START, vga_video_port_reg);
	outb_p(curs, vga_video_port_val);
	outb_p(VGA_CRTC_CURSOR_END, vga_video_port_reg);
	outb_p(cure, vga_video_port_val);
	spin_unlock_irqrestore(&vga_lock, flags);
}

static void vgacon_cursor(struct vc_data *c, int mode)
{
	if (c->vc_mode != KD_TEXT)
		return;

	vgacon_restore_screen(c);

	switch (mode) {
	case CM_ERASE:
		write_vga(14, (c->vc_pos - vga_vram_base) / 2);
	        if (vga_video_type >= VIDEO_TYPE_VGAC)
			vgacon_set_cursor_size(c->vc_x, 31, 30);
		else
			vgacon_set_cursor_size(c->vc_x, 31, 31);
		break;

	case CM_MOVE:
	case CM_DRAW:
		write_vga(14, (c->vc_pos - vga_vram_base) / 2);
		switch (c->vc_cursor_type & 0x0f) {
		case CUR_UNDERLINE:
			vgacon_set_cursor_size(c->vc_x,
					       c->vc_font.height -
					       (c->vc_font.height <
						10 ? 2 : 3),
					       c->vc_font.height -
					       (c->vc_font.height <
						10 ? 1 : 2));
			break;
		case CUR_TWO_THIRDS:
			vgacon_set_cursor_size(c->vc_x,
					       c->vc_font.height / 3,
					       c->vc_font.height -
					       (c->vc_font.height <
						10 ? 1 : 2));
			break;
		case CUR_LOWER_THIRD:
			vgacon_set_cursor_size(c->vc_x,
					       (c->vc_font.height * 2) / 3,
					       c->vc_font.height -
					       (c->vc_font.height <
						10 ? 1 : 2));
			break;
		case CUR_LOWER_HALF:
			vgacon_set_cursor_size(c->vc_x,
					       c->vc_font.height / 2,
					       c->vc_font.height -
					       (c->vc_font.height <
						10 ? 1 : 2));
			break;
		case CUR_NONE:
			if (vga_video_type >= VIDEO_TYPE_VGAC)
				vgacon_set_cursor_size(c->vc_x, 31, 30);
			else
				vgacon_set_cursor_size(c->vc_x, 31, 31);
			break;
		default:
			vgacon_set_cursor_size(c->vc_x, 1,
					       c->vc_font.height);
			break;
		}
		break;
	}
}

static int vgacon_doresize(struct vc_data *c,
		unsigned int width, unsigned int height)
{
	unsigned long flags;
	unsigned int scanlines = height * c->vc_font.height;
	u8 scanlines_lo = 0, r7 = 0, vsync_end = 0, mode, max_scan;

	spin_lock_irqsave(&vga_lock, flags);

	vgacon_xres = width * VGA_FONTWIDTH;
	vgacon_yres = height * c->vc_font.height;
	if (vga_video_type >= VIDEO_TYPE_VGAC) {
		outb_p(VGA_CRTC_MAX_SCAN, vga_video_port_reg);
		max_scan = inb_p(vga_video_port_val);

		if (max_scan & 0x80)
			scanlines <<= 1;

		outb_p(VGA_CRTC_MODE, vga_video_port_reg);
		mode = inb_p(vga_video_port_val);

		if (mode & 0x04)
			scanlines >>= 1;

		scanlines -= 1;
		scanlines_lo = scanlines & 0xff;

		outb_p(VGA_CRTC_OVERFLOW, vga_video_port_reg);
		r7 = inb_p(vga_video_port_val) & ~0x42;

		if (scanlines & 0x100)
			r7 |= 0x02;
		if (scanlines & 0x200)
			r7 |= 0x40;

		/* deprotect registers */
		outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
		vsync_end = inb_p(vga_video_port_val);
		outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
		outb_p(vsync_end & ~0x80, vga_video_port_val);
	}

	outb_p(VGA_CRTC_H_DISP, vga_video_port_reg);
	outb_p(width - 1, vga_video_port_val);
	outb_p(VGA_CRTC_OFFSET, vga_video_port_reg);
	outb_p(width >> 1, vga_video_port_val);

	if (vga_video_type >= VIDEO_TYPE_VGAC) {
		outb_p(VGA_CRTC_V_DISP_END, vga_video_port_reg);
		outb_p(scanlines_lo, vga_video_port_val);
		outb_p(VGA_CRTC_OVERFLOW, vga_video_port_reg);
		outb_p(r7,vga_video_port_val);

		/* reprotect registers */
		outb_p(VGA_CRTC_V_SYNC_END, vga_video_port_reg);
		outb_p(vsync_end, vga_video_port_val);
	}

	spin_unlock_irqrestore(&vga_lock, flags);
	return 0;
}

static int vgacon_switch(struct vc_data *c)
{
	int x = c->vc_cols * VGA_FONTWIDTH;
	int y = c->vc_rows * c->vc_font.height;
	int rows = screen_info.orig_video_lines * vga_default_font_height/
		c->vc_font.height;
	/*
	 * We need to save screen size here as it's the only way
	 * we can spot the screen has been resized and we need to
	 * set size of freshly allocated screens ourselves.
	 */
	vga_video_num_columns = c->vc_cols;
	vga_video_num_lines = c->vc_rows;

	/* We can only copy out the size of the video buffer here,
	 * otherwise we get into VGA BIOS */

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

		if ((vgacon_xres != x || vgacon_yres != y) &&
		    (!(vga_video_num_columns % 2) &&
		     vga_video_num_columns <= screen_info.orig_video_cols &&
		     vga_video_num_lines <= rows))
			vgacon_doresize(c, c->vc_cols, c->vc_rows);
	}

	vgacon_scrollback_init(c->vc_size_row);
	return 0;		/* Redrawing not needed */
}

static void vga_set_palette(struct vc_data *vc, unsigned char *table)
{
	int i, j;

	vga_w(state.vgabase, VGA_PEL_MSK, 0xff);
	for (i = j = 0; i < 16; i++) {
		vga_w(state.vgabase, VGA_PEL_IW, table[i]);
		vga_w(state.vgabase, VGA_PEL_D, vc->vc_palette[j++] >> 2);
		vga_w(state.vgabase, VGA_PEL_D, vc->vc_palette[j++] >> 2);
		vga_w(state.vgabase, VGA_PEL_D, vc->vc_palette[j++] >> 2);
	}
}

static int vgacon_set_palette(struct vc_data *vc, unsigned char *table)
{
#ifdef CAN_LOAD_PALETTE
	if (vga_video_type != VIDEO_TYPE_VGAC || vga_palette_blanked
	    || !CON_IS_VISIBLE(vc))
		return -EINVAL;
	vga_set_palette(vc, table);
	return 0;
#else
	return -EINVAL;
#endif
}

/* structure holding original VGA register settings */
static struct {
	unsigned char SeqCtrlIndex;	/* Sequencer Index reg.   */
	unsigned char CrtCtrlIndex;	/* CRT-Contr. Index reg.  */
	unsigned char CrtMiscIO;	/* Miscellaneous register */
	unsigned char HorizontalTotal;	/* CRT-Controller:00h */
	unsigned char HorizDisplayEnd;	/* CRT-Controller:01h */
	unsigned char StartHorizRetrace;	/* CRT-Controller:04h */
	unsigned char EndHorizRetrace;	/* CRT-Controller:05h */
	unsigned char Overflow;	/* CRT-Controller:07h */
	unsigned char StartVertRetrace;	/* CRT-Controller:10h */
	unsigned char EndVertRetrace;	/* CRT-Controller:11h */
	unsigned char ModeControl;	/* CRT-Controller:17h */
	unsigned char ClockingMode;	/* Seq-Controller:01h */
} vga_state;

static void vga_vesa_blank(struct vgastate *state, int mode)
{
	/* save original values of VGA controller registers */
	if (!vga_vesa_blanked) {
		spin_lock_irq(&vga_lock);
		vga_state.SeqCtrlIndex = vga_r(state->vgabase, VGA_SEQ_I);
		vga_state.CrtCtrlIndex = inb_p(vga_video_port_reg);
		vga_state.CrtMiscIO = vga_r(state->vgabase, VGA_MIS_R);
		spin_unlock_irq(&vga_lock);

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

	/* assure that video is enabled */
	/* "0x20" is VIDEO_ENABLE_bit in register 01 of sequencer */
	spin_lock_irq(&vga_lock);
	vga_wseq(state->vgabase, VGA_SEQ_CLOCK_MODE, vga_state.ClockingMode | 0x20);

	/* test for vertical retrace in process.... */
	if ((vga_state.CrtMiscIO & 0x80) == 0x80)
		vga_w(state->vgabase, VGA_MIS_W, vga_state.CrtMiscIO & 0xEF);

	/*
	 * Set <End of vertical retrace> to minimum (0) and
	 * <Start of vertical Retrace> to maximum (incl. overflow)
	 * Result: turn off vertical sync (VSync) pulse.
	 */
	if (mode & VESA_VSYNC_SUSPEND) {
		outb_p(0x10, vga_video_port_reg);	/* StartVertRetrace */
		outb_p(0xff, vga_video_port_val);	/* maximum value */
		outb_p(0x11, vga_video_port_reg);	/* EndVertRetrace */
		outb_p(0x40, vga_video_port_val);	/* minimum (bits 0..3)  */
		outb_p(0x07, vga_video_port_reg);	/* Overflow */
		outb_p(vga_state.Overflow | 0x84, vga_video_port_val);	/* bits 9,10 of vert. retrace */
	}

	if (mode & VESA_HSYNC_SUSPEND) {
		/*
		 * Set <End of horizontal retrace> to minimum (0) and
		 *  <Start of horizontal Retrace> to maximum
		 * Result: turn off horizontal sync (HSync) pulse.
		 */
		outb_p(0x04, vga_video_port_reg);	/* StartHorizRetrace */
		outb_p(0xff, vga_video_port_val);	/* maximum */
		outb_p(0x05, vga_video_port_reg);	/* EndHorizRetrace */
		outb_p(0x00, vga_video_port_val);	/* minimum (0) */
	}

	/* restore both index registers */
	vga_w(state->vgabase, VGA_SEQ_I, vga_state.SeqCtrlIndex);