s3c-fb: protect window-specific registers during updates

Newer hardware (S3C6410, S5P) have the ability to block updates from
shadow registers during reconfiguration.  Add protect calls for set_par
and clear protection when resetting.
Signed-off-by: NPawel Osciak <p.osciak@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: InKi Dae <inki.dae@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/video/s3c-fb.c

@@ -450,6 +450,8 @@ static int s3c_fb_set_par(struct fb_info *info)
 
 	dev_dbg(sfb->dev, "setting framebuffer parameters\n");
 
+	shadow_protect_win(win, 1);
+
 	switch (var->bits_per_pixel) {
 	case 32:
 	case 24:
@@ -632,6 +634,8 @@ static int s3c_fb_set_par(struct fb_info *info)
 	writel(data, regs + sfb->variant.wincon + (win_no * 4));
 	writel(0x0, regs + sfb->variant.winmap + (win_no * 4));
 
+	shadow_protect_win(win, 0);
+
 	return 0;
 }
 
@@ -1228,11 +1232,14 @@ static int __devinit s3c_fb_probe_win(struct s3c_fb *sfb, unsigned int win_no,
 static void s3c_fb_clear_win(struct s3c_fb *sfb, int win)
 {
 	void __iomem *regs = sfb->regs;
+	u32 reg;
 
 	writel(0, regs + sfb->variant.wincon + (win * 4));
 	writel(0, regs + VIDOSD_A(win, sfb->variant));
 	writel(0, regs + VIDOSD_B(win, sfb->variant));
 	writel(0, regs + VIDOSD_C(win, sfb->variant));
+	reg = readl(regs + SHADOWCON);
+	writel(reg & ~SHADOWCON_WINx_PROTECT(win), regs + SHADOWCON);
 }
 
 static int __devinit s3c_fb_probe(struct platform_device *pdev)