From: Sean Paul <sean@poorly.run>
To: Douglas Anderson <dianders@chromium.org>
Cc: Heiko Stuebner <heiko@sntech.de>,
Sandy Huang <hjc@rock-chips.com>,
Andrzej Hajda <a.hajda@samsung.com>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
Rob Herring <robh+dt@kernel.org>,
linux-rockchip@lists.infradead.org,
Neil Armstrong <narmstrong@baylibre.com>,
Mark Rutland <mark.rutland@arm.com>,
mka@chromium.org, Sean Paul <seanpaul@chromium.org>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org, David Airlie <airlied@linux.ie>,
linux-arm-kernel@lists.infradead.org,
Daniel Vetter <daniel@ffwll.ch>
Subject: Re: [PATCH 1/5] dt-bindings: drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus
Date: Wed, 5 Jun 2019 16:21:01 -0400 [thread overview]
Message-ID: <20190605202101.GG17077@art_vandelay> (raw)
In-Reply-To: <20190502225336.206885-1-dianders@chromium.org>
On Thu, May 02, 2019 at 03:53:32PM -0700, Douglas Anderson wrote:
> 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.
Pushed to drm-misc-next along with patch 2. I'll let Heiko land the dts patches.
Thanks!
Sean
>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
>
> .../bindings/display/rockchip/dw_hdmi-rockchip.txt | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/display/rockchip/dw_hdmi-rockchip.txt b/Documentation/devicetree/bindings/display/rockchip/dw_hdmi-rockchip.txt
> index 39143424a474..8346bac81f1c 100644
> --- a/Documentation/devicetree/bindings/display/rockchip/dw_hdmi-rockchip.txt
> +++ b/Documentation/devicetree/bindings/display/rockchip/dw_hdmi-rockchip.txt
> @@ -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 {
> --
> 2.21.0.1020.gf2820cf01a-goog
>
--
Sean Paul, Software Engineer, Google / Chromium OS
prev parent reply other threads:[~2019-06-05 20:21 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-02 22:53 [PATCH 1/5] dt-bindings: drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus Douglas Anderson
2019-05-02 22:53 ` [PATCH 2/5] " Douglas Anderson
2019-05-15 18:20 ` Sean Paul
2019-05-15 18:36 ` Doug Anderson
2019-05-15 18:42 ` Sean Paul
2019-05-02 22:53 ` [PATCH 3/5] ARM: dts: rockchip: Switch to builtin HDMI DDC bus on rk3288-veyron Douglas Anderson
2019-05-15 18:25 ` Sean Paul
2019-06-06 10:28 ` Heiko Stuebner
2019-05-02 22:53 ` [PATCH 4/5] ARM: dts: rockchip: Add unwedge pinctrl entries for dw_hdmi on rk3288 Douglas Anderson
2019-05-15 18:25 ` Sean Paul
2019-05-02 22:53 ` [PATCH 5/5] ARM: dts: rockchip: Add HDMI i2c unwedging for rk3288-veyron Douglas Anderson
2019-05-15 18:26 ` Sean Paul
2019-05-14 20:49 ` [PATCH 1/5] dt-bindings: drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus Rob Herring
2019-06-05 20:21 ` Sean Paul [this message]
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