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authorMaurus Cuelenaere <mcuelenaere@gmail.com>2010-08-10 18:02:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-11 08:59:12 -0700
commit2bb567a38950f0917aecfe1a3e46720d8bbb0020 (patch)
tree58187f4c8263dd3efcae7b018066517caece374e /drivers/video
parent04ab9ef97771ba88789672a1f0d0ddcf8dbc0924 (diff)
s3c-fb: automatically calculate pixel clock when none is given
Add a simple algorithm which calculates the pixel clock based on the video mode parameters. This is only done when no pixel clock is supplied through the platform data. This allows drivers to omit the pixel clock data and thus share the algorithm used for calculating it. Signed-off-by: Maurus Cuelenaere <mcuelenaere@gmail.com> Cc: Pawel Osciak <p.osciak@samsung.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: InKi Dae <inki.dae@samsung.com> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Russell King <rmk@arm.linux.org.uk> Tested-by: Donghwa Lee <yiffie9819@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video')
-rw-r--r--drivers/video/s3c-fb.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/video/s3c-fb.c b/drivers/video/s3c-fb.c
index 8ea974dd92c..f9aca9d13d1 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) {