Re: [PATCH v2] of: Add videomode helper
flat view
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Date: 2012-07-05 14:08:07
Also in:
dri-devel, linux-devicetree
Hi Sascha, Thanks for the patch. On Wednesday 04 July 2012 09:56:35 Sascha Hauer wrote:
quoted hunk ↗ jump to hunk
This patch adds a helper function for parsing videomodes from the devicetree. The videomode can be either converted to a struct drm_display_mode or a struct fb_videomode. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> --- changes since v1: - use hyphens instead of underscores for property names .../devicetree/bindings/video/displaymode | 40 ++++++++ drivers/of/Kconfig | 5 + drivers/of/Makefile | 1 + drivers/of/of_videomode.c | 108 +++++++++++++++++ include/linux/of_videomode.h | 19 ++++ 5 files changed, 173 insertions(+) create mode 100644 Documentation/devicetree/bindings/video/displaymode create mode 100644 drivers/of/of_videomode.c create mode 100644 include/linux/of_videomode.hdiff --git a/Documentation/devicetree/bindings/video/displaymodeb/Documentation/devicetree/bindings/video/displaymode new file mode 100644 index 0000000..43cc17d--- /dev/null +++ b/Documentation/devicetree/bindings/video/displaymode@@ -0,0 +1,40 @@ +videomode bindings +========= + +Required properties: + - xres, yres: Display resolution + - left-margin, right-margin, hsync-len: Horizontal Display timingparameters + in pixels + upper-margin, lower-margin, vsync-len: Vertical display timing parameters in + lines + - clock: displayclock in Hz + +Optional properties: + - width-mm, height-mm: Display dimensions in mm
I've always had mixed feelings about the physical display dimension being part of the display mode. Those are properties of the panel/display instead of the mode. Storing them as part of the mode can be convenient, but we then run into consistency issues (developers have to remember in which display mode instances the values are available, and in which instances they're set to 0 for instance). If we want to clean this up, this patch would be a good occasion.
+ - hsync-active-high (bool): Hsync pulse is active high
+ - vsync-active-high (bool): Vsync pulse is active high
+ - interlaced (bool): This is an interlaced mode
+ - doublescan (bool): This is a doublescan mode
+
+There are different ways of describing a display mode. The devicetree
representation +corresponds to the one used by the Linux Framebuffer
framework described here in +Documentation/fb/framebuffer.txt. This
representation has been chosen because it's +the only format which does not
allow for inconsistent parameters.Unlike the Framebuffer +framework the
devicetree has the clock in Hz instead of ps.
+
+Example:
+
+ display@0 {
+ /* 1920x1080p24 */
+ clock = <52000000>;
+ xres = <1920>;
+ yres = <1080>;
+ left-margin = <25>;
+ right-margin = <25>;
+ hsync-len = <25>;
+ lower-margin = <2>;
+ upper-margin = <2>;
+ vsync-len = <2>;
+ hsync-active-high;
+ };
+-- Regards, Laurent Pinchart