fbcon.c

Linux环境下视频显示卡设备的驱动程序源代码

	int good_pan = (cap & FBINFO_HWACCEL_YPAN) &&
		divides(ypan, vc->vc_font.height) && vyres > yres;
	int good_wrap = (cap & FBINFO_HWACCEL_YWRAP) &&
		divides(ywrap, vc->vc_font.height) &&
		divides(vc->vc_font.height, vyres) &&
		divides(vc->vc_font.height, yres);
	int reading_fast = cap & FBINFO_READS_FAST;
	int fast_copyarea = (cap & FBINFO_HWACCEL_COPYAREA) &&
		!(cap & FBINFO_HWACCEL_DISABLED);
	int fast_imageblit = (cap & FBINFO_HWACCEL_IMAGEBLIT) &&
		!(cap & FBINFO_HWACCEL_DISABLED);

	p->vrows = vyres/fh;
	if (yres > (fh * (vc->vc_rows + 1)))
		p->vrows -= (yres - (fh * vc->vc_rows)) / fh;
	if ((yres % fh) && (vyres % fh < yres % fh))
		p->vrows--;

	if (good_wrap || good_pan) {
		if (reading_fast || fast_copyarea)
			p->scrollmode = good_wrap ?
				SCROLL_WRAP_MOVE : SCROLL_PAN_MOVE;
		else
			p->scrollmode = good_wrap ? SCROLL_REDRAW :
				SCROLL_PAN_REDRAW;
	} else {
		if (reading_fast || (fast_copyarea && !fast_imageblit))
			p->scrollmode = SCROLL_MOVE;
		else
			p->scrollmode = SCROLL_REDRAW;
	}
}

static int fbcon_resize(struct vc_data *vc, unsigned int width, 
			unsigned int height, unsigned int user)
{
	struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
	struct fbcon_ops *ops = info->fbcon_par;
	struct display *p = &fb_display[vc->vc_num];
	struct fb_var_screeninfo var = info->var;
	int x_diff, y_diff, virt_w, virt_h, virt_fw, virt_fh;

	virt_w = FBCON_SWAP(ops->rotate, width, height);
	virt_h = FBCON_SWAP(ops->rotate, height, width);
	virt_fw = FBCON_SWAP(ops->rotate, vc->vc_font.width,
				 vc->vc_font.height);
	virt_fh = FBCON_SWAP(ops->rotate, vc->vc_font.height,
				 vc->vc_font.width);
	var.xres = virt_w * virt_fw;
	var.yres = virt_h * virt_fh;
	x_diff = info->var.xres - var.xres;
	y_diff = info->var.yres - var.yres;
	if (x_diff < 0 || x_diff > virt_fw ||
	    y_diff < 0 || y_diff > virt_fh) {
		const struct fb_videomode *mode;

		DPRINTK("attempting resize %ix%i\n", var.xres, var.yres);
		mode = fb_find_best_mode(&var, &info->modelist);
		if (mode == NULL)
			return -EINVAL;
		display_to_var(&var, p);
		fb_videomode_to_var(&var, mode);

		if (virt_w > var.xres/virt_fw || virt_h > var.yres/virt_fh)
			return -EINVAL;

		DPRINTK("resize now %ix%i\n", var.xres, var.yres);
		if (CON_IS_VISIBLE(vc)) {
			var.activate = FB_ACTIVATE_NOW |
				FB_ACTIVATE_FORCE;
			fb_set_var(info, &var);
		}
		var_to_display(p, &info->var, info);
		ops->var = info->var;
	}
	updatescrollmode(p, info, vc);
	return 0;
}

static int fbcon_switch(struct vc_data *vc)
{
	struct fb_info *info, *old_info = NULL;
	struct fbcon_ops *ops;
	struct display *p = &fb_display[vc->vc_num];
	struct fb_var_screeninfo var;
	int i, prev_console, charcnt = 256;

	info = registered_fb[con2fb_map[vc->vc_num]];
	ops = info->fbcon_par;

	if (softback_top) {
		if (softback_lines)
			fbcon_set_origin(vc);
		softback_top = softback_curr = softback_in = softback_buf;
		softback_lines = 0;
		fbcon_update_softback(vc);
	}

	if (logo_shown >= 0) {
		struct vc_data *conp2 = vc_cons[logo_shown].d;

		if (conp2->vc_top == logo_lines
		    && conp2->vc_bottom == conp2->vc_rows)
			conp2->vc_top = 0;
		logo_shown = FBCON_LOGO_CANSHOW;
	}

	prev_console = ops->currcon;
	if (prev_console != -1)
		old_info = registered_fb[con2fb_map[prev_console]];
	/*
	 * FIXME: If we have multiple fbdev's loaded, we need to
	 * update all info->currcon.  Perhaps, we can place this
	 * in a centralized structure, but this might break some
	 * drivers.
	 *
	 * info->currcon = vc->vc_num;
	 */
	for (i = 0; i < FB_MAX; i++) {
		if (registered_fb[i] != NULL && registered_fb[i]->fbcon_par) {
			struct fbcon_ops *o = registered_fb[i]->fbcon_par;

			o->currcon = vc->vc_num;
		}
	}
	memset(&var, 0, sizeof(struct fb_var_screeninfo));
	display_to_var(&var, p);
	var.activate = FB_ACTIVATE_NOW;

	/*
	 * make sure we don't unnecessarily trip the memcmp()
	 * in fb_set_var()
	 */
	info->var.activate = var.activate;
	var.vmode |= info->var.vmode & ~FB_VMODE_MASK;
	fb_set_var(info, &var);
	ops->var = info->var;

	if (old_info != NULL && (old_info != info ||
				 info->flags & FBINFO_MISC_ALWAYS_SETPAR)) {
		if (info->fbops->fb_set_par)
			info->fbops->fb_set_par(info);

		if (old_info != info)
			fbcon_del_cursor_timer(old_info);
	}

	if (fbcon_is_inactive(vc, info) ||
	    ops->blank_state != FB_BLANK_UNBLANK)
		fbcon_del_cursor_timer(info);
	else
		fbcon_add_cursor_timer(info);

	set_blitting_type(vc, info);
	ops->cursor_reset = 1;

	if (ops->rotate_font && ops->rotate_font(info, vc)) {
		ops->rotate = FB_ROTATE_UR;
		set_blitting_type(vc, info);
	}

	vc->vc_can_do_color = (fb_get_color_depth(&info->var, &info->fix)!=1);
	vc->vc_complement_mask = vc->vc_can_do_color ? 0x7700 : 0x0800;

	if (p->userfont)
		charcnt = FNTCHARCNT(vc->vc_font.data);

	if (charcnt > 256)
		vc->vc_complement_mask <<= 1;

	updatescrollmode(p, info, vc);

	switch (p->scrollmode) {
	case SCROLL_WRAP_MOVE:
		scrollback_phys_max = p->vrows - vc->vc_rows;
		break;
	case SCROLL_PAN_MOVE:
	case SCROLL_PAN_REDRAW:
		scrollback_phys_max = p->vrows - 2 * vc->vc_rows;
		if (scrollback_phys_max < 0)
			scrollback_phys_max = 0;
		break;
	default:
		scrollback_phys_max = 0;
		break;
	}

	scrollback_max = 0;
	scrollback_current = 0;

	if (!fbcon_is_inactive(vc, info)) {
	    ops->var.xoffset = ops->var.yoffset = p->yscroll = 0;
	    ops->update_start(info);
	}

	fbcon_set_palette(vc, color_table); 	
	fbcon_clear_margins(vc, 0);

	if (logo_shown == FBCON_LOGO_DRAW) {

		logo_shown = fg_console;
		/* This is protected above by initmem_freed */
		fb_show_logo(info, ops->rotate);
		update_region(vc,
			      vc->vc_origin + vc->vc_size_row * vc->vc_top,
			      vc->vc_size_row * (vc->vc_bottom -
						 vc->vc_top) / 2);
		return 0;
	}
	return 1;
}

static void fbcon_generic_blank(struct vc_data *vc, struct fb_info *info,
				int blank)
{
	struct fb_event event;

	if (blank) {
		unsigned short charmask = vc->vc_hi_font_mask ?
			0x1ff : 0xff;
		unsigned short oldc;

		oldc = vc->vc_video_erase_char;
		vc->vc_video_erase_char &= charmask;
		fbcon_clear(vc, 0, 0, vc->vc_rows, vc->vc_cols);
		vc->vc_video_erase_char = oldc;
	}


	event.info = info;
	event.data = &blank;
	fb_notifier_call_chain(FB_EVENT_CONBLANK, &event);
}

static int fbcon_blank(struct vc_data *vc, int blank, int mode_switch)
{
	struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
	struct fbcon_ops *ops = info->fbcon_par;

	if (mode_switch) {
		struct fb_var_screeninfo var = info->var;

		ops->graphics = 1;

		if (!blank) {
			if (info->fbops->fb_save_state)
				info->fbops->fb_save_state(info);
			var.activate = FB_ACTIVATE_NOW | FB_ACTIVATE_FORCE;
			fb_set_var(info, &var);
			ops->graphics = 0;
			ops->var = info->var;
		} else if (info->fbops->fb_restore_state)
			info->fbops->fb_restore_state(info);
	}

 	if (!fbcon_is_inactive(vc, info)) {
		if (ops->blank_state != blank) {
			ops->blank_state = blank;
			fbcon_cursor(vc, blank ? CM_ERASE : CM_DRAW);
			ops->cursor_flash = (!blank);

			if (!(info->flags & FBINFO_MISC_USEREVENT))
				if (fb_blank(info, blank))
					fbcon_generic_blank(vc, info, blank);
		}

		if (!blank)
			update_screen(vc);
	}

	if (mode_switch || fbcon_is_inactive(vc, info) ||
	    ops->blank_state != FB_BLANK_UNBLANK)
		fbcon_del_cursor_timer(info);
	else
		fbcon_add_cursor_timer(info);

	return 0;
}

static int fbcon_get_font(struct vc_data *vc, struct console_font *font)
{
	u8 *fontdata = vc->vc_font.data;
	u8 *data = font->data;
	int i, j;

	font->width = vc->vc_font.width;
	font->height = vc->vc_font.height;
	font->charcount = vc->vc_hi_font_mask ? 512 : 256;
	if (!font->data)
		return 0;

	if (font->width <= 8) {
		j = vc->vc_font.height;
		for (i = 0; i < font->charcount; i++) {
			memcpy(data, fontdata, j);
			memset(data + j, 0, 32 - j);
			data += 32;
			fontdata += j;
		}
	} else if (font->width <= 16) {
		j = vc->vc_font.height * 2;
		for (i = 0; i < font->charcount; i++) {
			memcpy(data, fontdata, j);
			memset(data + j, 0, 64 - j);
			data += 64;
			fontdata += j;
		}
	} else if (font->width <= 24) {
		for (i = 0; i < font->charcount; i++) {
			for (j = 0; j < vc->vc_font.height; j++) {
				*data++ = fontdata[0];
				*data++ = fontdata[1];
				*data++ = fontdata[2];
				fontdata += sizeof(u32);
			}
			memset(data, 0, 3 * (32 - j));
			data += 3 * (32 - j);
		}
	} else {
		j = vc->vc_font.height * 4;
		for (i = 0; i < font->charcount; i++) {
			memcpy(data, fontdata, j);
			memset(data + j, 0, 128 - j);
			data += 128;
			fontdata += j;
		}
	}
	return 0;
}

static int fbcon_do_set_font(struct vc_data *vc, int w, int h,
			     const u8 * data, int userfont)
{
	struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
	struct fbcon_ops *ops = info->fbcon_par;
	struct display *p = &fb_display[vc->vc_num];
	int resize;
	int cnt;
	char *old_data = NULL;

	if (CON_IS_VISIBLE(vc) && softback_lines)
		fbcon_set_origin(vc);

	resize = (w != vc->vc_font.width) || (h != vc->vc_font.height);
	if (p->userfont)
		old_data = vc->vc_font.data;
	if (userfont)
		cnt = FNTCHARCNT(data);
	else
		cnt = 256;
	vc->vc_font.data = (void *)(p->fontdata = data);
	if ((p->userfont = userfont))
		REFCOUNT(data)++;
	vc->vc_font.width = w;
	vc->vc_font.height = h;
	if (vc->vc_hi_font_mask && cnt == 256) {
		vc->vc_hi_font_mask = 0;
		if (vc->vc_can_do_color) {
			vc->vc_complement_mask >>= 1;
			vc->vc_s_complement_mask >>= 1;
		}
			
		/* ++Edmund: reorder the attribute bits */
		if (vc->vc_can_do_color) {
			unsigned short *cp =
			    (unsigned short *) vc->vc_origin;
			int count = vc->vc_screenbuf_size / 2;
			unsigned short c;
			for (; count > 0; count--, cp++) {
				c = scr_readw(cp);
				scr_writew(((c & 0xfe00) >> 1) |
					   (c & 0xff), cp);
			}
			c = vc->vc_video_erase_char;
			vc->vc_video_erase_char =
			    ((c & 0xfe00) >> 1) | (c & 0xff);
			vc->vc_attr >>= 1;
		}
	} else if (!vc->vc_hi_font_mask && cnt == 512) {
		vc->vc_hi_font_mask = 0x100;
		if (vc->vc_can_do_color) {
			vc->vc_complement_mask <<= 1;
			vc->vc_s_complement_mask <<= 1;
		}
			
		/* ++Edmund: reorder the attribute bits */
		{
			unsigned short *cp =
			    (unsigned short *) vc->vc_origin;
			int count = vc->vc_screenbuf_size / 2;
			unsigned short c;
			for (; count > 0; count--, cp++) {
				unsigned short newc;
				c = scr_readw(cp);
				if (vc->vc_can_do_color)
					newc =
					    ((c & 0xff00) << 1) | (c &
								   0xff);
				else
					newc = c & ~0x100;
				scr_writew(newc, cp);
			}
			c = vc->vc_video_erase_char;
			if (vc->vc_can_do_color) {
				vc->vc_video_erase_char =
				    ((c & 0xff00) << 1) | (c & 0xff);
				vc->vc_attr <<= 1;
			} else
				vc->vc_video_erase_char = c & ~0x100;
		}

	}

	if (resize) {
		int cols, rows;

		cols = FBCON_SWAP(ops->rotate, info->var.xres, info->var.yres);
		rows = FBCON_SWAP(ops->rotate, info->var.yres, info->var.xres);
		cols /= w;
		rows /= h;
		vc_resize(vc, cols, rows);
		if (CON_IS_VISIBLE(vc) && softback_buf)
			fbcon_update_softback(vc);
	} else if (CON_IS_VISIBLE(vc)
		   && vc->vc_mode == KD_TEXT) {
		fbcon_clear_margins(vc, 0);
		update_screen(vc);
	}

	if (old_data && (--REFCOUNT(old_data) == 0))
		kfree(old_data - FONT_EXTRA_WORDS * sizeof(int));
	return 0;
}

static int fbcon_copy_font(struct vc_data *vc, int con)
{
	struct display *od = &fb_display[con];
	struct console_font *f = &vc->vc_font;

	if (od->fontdata == f->data)
		return 0;	/* already the same font... */
	return fbcon_do_set_font(vc, f->width, f->height, od->fontdata, od->userfont);
}

/*
 *  User asked to set font; we are guaranteed that
 *	a) width and height are in range 1..32
 *	b) charcount does not exceed 512
 *  but lets not assume that, since someone might someday want to use larger
 *  fonts. And charcount of 512 is small for unicode support.
 *
 *  However, user space gives the font in 32 rows , regardless of
 *  actual font height. So a new API is needed if support for larger fonts
 *  is ever implemented.
 */

static int fbcon_set_font(struct vc_data *vc, struct console_font *font, unsigned flags)
{
	struct fb_info *info = registered_fb[con2fb_map[vc->vc_num]];
	unsigned charcount = font->charcount;
	int w = font->width;
	int h = font->height;
	int size;
	int i, csum;
	u8 *new_data, *data = font->data;
	int pitch = (font->width+7) >> 3;

	/* Is there a reason why fbconsole couldn't handle any charcount >256?
	 * If not this check should be changed to charcount < 256 */
	if (charcount != 256 && charcount != 512)
		return -EINVAL;

	/* Make sure drawing engine can handle the font */
	if (!(info->pixmap.blit_x & (1 << (font->width - 1))) ||
	    !(info->pixmap.blit_y & (1 << (font->height - 1))))
		return -EINVAL;

	/* Make sure driver can handle the font length */
	if (fbcon_invalid_charcount(info, charcount))
		return -EINVAL;

	size = h * pitch * charcount;

	new_data = kmalloc(FONT_EXTRA_WORDS * sizeof(int) + size, GFP_USER);

	if (!new_data)
		return -ENOMEM;

	new_data += FONT_EXTRA_WORDS * sizeof(int);
	FNTSIZE(new_data) = size;
	FNTCHARCNT(new_data) = charcount;
	REFCOUNT(new_data) = 0;	/* usage counter */
	for (i=0; i< charcount; i++) {
		memcpy(new_data + i*h*pitch, data +  i*32*pitch, h*pitch);
	}

	/* Since linux has a nice crc32 function use it for counting font
	 * checksums. */
	csum = crc32(0, new_data, size);

	FNTSUM(new_data) = csum;
	/* Check if the same font is on some other console already */
	for (i = first_fb_vc; i <= last_fb_vc; i++) {
		struct vc_data *tmp = vc_cons[i].d;
		
		if (fb_display[i].userfont