1 files changed, 25 insertions, 0 deletions

diff --git a/drivers/video/s3c-fb.c b/drivers/video/s3c-fb.c
index 8ea974dd92c5..f9aca9d13d1b 100644
--- a/drivers/video/s3c-fb.c
+++ b/drivers/video/s3c-fb.c
@@ -1027,6 +1027,28 @@ static struct fb_ops s3c_fb_ops = {
 };
 
 /**
+ * s3c_fb_missing_pixclock() - calculates pixel clock
+ * @mode: The video mode to change.
+ *
+ * Calculate the pixel clock when none has been given through platform data.
+ */
+static void __devinit s3c_fb_missing_pixclock(struct fb_videomode *mode)
+{
+        u64 pixclk = 1000000000000ULL;
+        u32 div;
+
+        div  = mode->left_margin + mode->hsync_len + mode->right_margin +
+               mode->xres;
+        div *= mode->upper_margin + mode->vsync_len + mode->lower_margin +
+               mode->yres;
+        div *= mode->refresh ? : 60;
+
+        do_div(pixclk, div);
+
+        mode->pixclock = pixclk;
+}
+
+/**
  * s3c_fb_alloc_memory() - allocate display memory for framebuffer window
  * @sfb: The base resources for the hardware.
  * @win: The window to initialise memory for.
@@ -1364,6 +1386,9 @@ static int __devinit s3c_fb_probe(struct platform_device *pdev)
                 if (!pd->win[win])
                         continue;
 
+                if (!pd->win[win]->win_mode.pixclock)
+                        s3c_fb_missing_pixclock(&pd->win[win]->win_mode);
+
                 ret = s3c_fb_probe_win(sfb, win, fbdrv->win[win],
                                        &sfb->windows[win]);
                 if (ret < 0) {