Commit c6036250 authored May 02, 2019 by Douglas Anderson Committed by Sean Paul Jun 05, 2019

dt-bindings: drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus



In certain situations it was seen that we could wedge up the DDC bus
on the HDMI adapter on rk3288.  The only way to unwedge was to mux one
of the pins over to GPIO output-driven-low temporarily and then
quickly mux back.  Full details can be found in the patch
("drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus").

Since unwedge requires remuxing the pins, we first need to add to the
bindings so that we can specify what state the pins should be in for
unwedging.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190502225336.206885-1-dianders@chromium.org

parent 7f1d39ef

Documentation/devicetree/bindings/display/rockchip/dw_hdmi-rockchip.txt

+7 −0

Original line number	Diff line number	Diff line
		@@ -38,6 +38,13 @@ Optional properties
		- phys: from general PHY binding: the phandle for the PHY device.
		- phy-names: Should be "hdmi" if phys references an external phy.

		Optional pinctrl entry:
		- If you have both a "unwedge" and "default" pinctrl entry, dw_hdmi
		will switch to the unwedge pinctrl state for 10ms if it ever gets an
		i2c timeout. It's intended that this unwedge pinctrl entry will
		cause the SDA line to be driven low to work around a hardware
		errata.

		Example:

		hdmi: hdmi@ff980000 {

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