video: s3c-fb: add shadow register protect

Shadow registers should be protectd whenever the registers are
updated. Shadow registers are updated after SHADOWCON shadow
register is cleared.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

drivers/video/s3c-fb.c

@@ -812,12 +812,16 @@ static int s3c_fb_blank(int blank_mode, struct fb_info *info)
 
 	case FB_BLANK_NORMAL:
 		/* disable the DMA and display 0x0 (black) */
+		shadow_protect_win(win, 1);
 		writel(WINxMAP_MAP | WINxMAP_MAP_COLOUR(0x0),
 		       sfb->regs + sfb->variant.winmap + (index * 4));
+		shadow_protect_win(win, 0);
 		break;
 
 	case FB_BLANK_UNBLANK:
+		shadow_protect_win(win, 1);
 		writel(0x0, sfb->regs + sfb->variant.winmap + (index * 4));
+		shadow_protect_win(win, 0);
 		wincon |= WINCONx_ENWIN;
 		sfb->enabled |= (1 << index);
 		break;
@@ -828,7 +832,9 @@ static int s3c_fb_blank(int blank_mode, struct fb_info *info)
 		return 1;
 	}
 
+	shadow_protect_win(win, 1);
 	writel(wincon, sfb->regs + sfb->variant.wincon + (index * 4));
+	shadow_protect_win(win, 0);
 
 	/* Check the enabled state to see if we need to be running the
 	 * main LCD interface, as if there are no active windows then
@@ -847,8 +853,11 @@ static int s3c_fb_blank(int blank_mode, struct fb_info *info)
 	/* we're stuck with this until we can do something about overriding
 	 * the power control using the blanking event for a single fb.
 	 */
-	if (index == sfb->pdata->default_win)
+	if (index == sfb->pdata->default_win) {
+		shadow_protect_win(win, 1);
 		s3c_fb_enable(sfb, blank_mode != FB_BLANK_POWERDOWN ? 1 : 0);
+		shadow_protect_win(win, 0);
+	}
 
 	return 0;
 }
@@ -1551,10 +1560,15 @@ static int s3c_fb_resume(struct device *dev)
 
 	for (win_no = 0; win_no < sfb->variant.nr_windows - 1; win_no++) {
 		void __iomem *regs = sfb->regs + sfb->variant.keycon;
+		win = sfb->windows[win_no];
+		if (!win)
+			continue;
 
+		shadow_protect_win(win, 1);
 		regs += (win_no * 8);
 		writel(0xffffff, regs + WKEYCON0);
 		writel(0xffffff, regs + WKEYCON1);
+		shadow_protect_win(win, 0);
 	}
 
 	/* restore framebuffers */