[PATCH 1/5] dt-bindings: drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus

[PATCH 1/5] dt-bindings: drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus

[Douglas Anderson]

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.

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

[PATCH 3/5] ARM: dts: rockchip: Switch to builtin HDMI DDC bus on rk3288-veyron

[Douglas Anderson]

Downstream Chrome OS kernels use the builtin DDC bus from dw_hdmi on
veyron.  This is the only way to get them to negotiate HDCP.

Although HDCP isn't currently all supported upstream, it still seems
like it makes sense to use dw_hdmi's builtin I2C.  Maybe eventually we
can get HDCP negotiation working.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 arch/arm/boot/dts/rk3288-veyron.dtsi | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/arch/arm/boot/dts/rk3288-veyron.dtsi b/arch/arm/boot/dts/rk3288-veyron.dtsi
index 1252522392c7..e1bee663d2c5 100644
--- a/arch/arm/boot/dts/rk3288-veyron.dtsi
+++ b/arch/arm/boot/dts/rk3288-veyron.dtsi
@@ -163,7 +163,8 @@
 };
 
 &hdmi {
-	ddc-i2c-bus = <&i2c5>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&hdmi_ddc>;
 	status = "okay";
 };
 
@@ -334,14 +335,6 @@
 	i2c-scl-rising-time-ns = <300>;		/* 225ns measured */
 };
 
-&i2c5 {
-	status = "okay";
-
-	clock-frequency = <100000>;
-	i2c-scl-falling-time-ns = <300>;
-	i2c-scl-rising-time-ns = <1000>;
-};
-
 &io_domains {
 	status = "okay";
 
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH 4/5] ARM: dts: rockchip: Add unwedge pinctrl entries for dw_hdmi on rk3288

[Douglas Anderson]

This adds the "unwedge" pinctrl entries introduced by a recent dw_hdmi
change that can unwedge the dw_hdmi i2c bus in some cases.  It's
expected that any boards using this would add:

  pinctrl-names = "default", "unwedge";
  pinctrl-0 = <&hdmi_ddc>;
  pinctrl-1 = <&hdmi_ddc_unwedge>;

Note that this isn't added by default because some boards may choose
to mux i2c5 for their DDC bus (if that is more tested for them).

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 arch/arm/boot/dts/rk3288.dtsi | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi
index 74c9517c4f92..eebc04fa1e4d 100644
--- a/arch/arm/boot/dts/rk3288.dtsi
+++ b/arch/arm/boot/dts/rk3288.dtsi
@@ -1545,6 +1545,15 @@
 				rockchip,pins = <7 RK_PC3 2 &pcfg_pull_none>,
 						<7 RK_PC4 2 &pcfg_pull_none>;
 			};
+
+			hdmi_ddc_unwedge: hdmi-ddc-unwedge {
+				rockchip,pins = <7 RK_PC3 RK_FUNC_GPIO &pcfg_output_low>,
+						<7 RK_PC4 2 &pcfg_pull_none>;
+			};
+		};
+
+		pcfg_output_low: pcfg-output-low {
+			output-low;
 		};
 
 		pcfg_pull_up: pcfg-pull-up {
-- 
2.21.0.1020.gf2820cf01a-goog

[PATCH 5/5] ARM: dts: rockchip: Add HDMI i2c unwedging for rk3288-veyron

[Douglas Anderson]

Veyron uses the builtin i2c controller that's part of dw-hdmi.  Hook
up the unwedging feature.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

 arch/arm/boot/dts/rk3288-veyron.dtsi | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/rk3288-veyron.dtsi b/arch/arm/boot/dts/rk3288-veyron.dtsi
index e1bee663d2c5..340b276b6333 100644
--- a/arch/arm/boot/dts/rk3288-veyron.dtsi
+++ b/arch/arm/boot/dts/rk3288-veyron.dtsi
@@ -163,8 +163,9 @@
 };
 
 &hdmi {
-	pinctrl-names = "default";
+	pinctrl-names = "default", "unwedge";
 	pinctrl-0 = <&hdmi_ddc>;
+	pinctrl-1 = <&hdmi_ddc_unwedge>;
 	status = "okay";
 };
 
-- 
2.21.0.1020.gf2820cf01a-goog

Re: [PATCH 1/5] dt-bindings: drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus

[Rob Herring]

On Thu,  2 May 2019 15:53:32 -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.
> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> 
>  .../bindings/display/rockchip/dw_hdmi-rockchip.txt         | 7 +++++++
>  1 file changed, 7 insertions(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH 3/5] ARM: dts: rockchip: Switch to builtin HDMI DDC bus on rk3288-veyron

[Sean Paul]

On Thu, May 02, 2019 at 03:53:34PM -0700, Douglas Anderson wrote:
> Downstream Chrome OS kernels use the builtin DDC bus from dw_hdmi on
> veyron.  This is the only way to get them to negotiate HDCP.
> 
> Although HDCP isn't currently all supported upstream, it still seems
> like it makes sense to use dw_hdmi's builtin I2C.  Maybe eventually we
> can get HDCP negotiation working.
> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Reviewed-by: Sean Paul <sean@poorly.run>

> ---
> 
>  arch/arm/boot/dts/rk3288-veyron.dtsi | 11 ++---------
>  1 file changed, 2 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/rk3288-veyron.dtsi b/arch/arm/boot/dts/rk3288-veyron.dtsi
> index 1252522392c7..e1bee663d2c5 100644
> --- a/arch/arm/boot/dts/rk3288-veyron.dtsi
> +++ b/arch/arm/boot/dts/rk3288-veyron.dtsi
> @@ -163,7 +163,8 @@
>  };
>  
>  &hdmi {
> -	ddc-i2c-bus = <&i2c5>;
> +	pinctrl-names = "default";
> +	pinctrl-0 = <&hdmi_ddc>;
>  	status = "okay";
>  };
>  
> @@ -334,14 +335,6 @@
>  	i2c-scl-rising-time-ns = <300>;		/* 225ns measured */
>  };
>  
> -&i2c5 {
> -	status = "okay";
> -
> -	clock-frequency = <100000>;
> -	i2c-scl-falling-time-ns = <300>;
> -	i2c-scl-rising-time-ns = <1000>;
> -};
> -
>  &io_domains {
>  	status = "okay";
>  
> -- 
> 2.21.0.1020.gf2820cf01a-goog
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS

Re: [PATCH 4/5] ARM: dts: rockchip: Add unwedge pinctrl entries for dw_hdmi on rk3288

[Sean Paul]

On Thu, May 02, 2019 at 03:53:35PM -0700, Douglas Anderson wrote:
> This adds the "unwedge" pinctrl entries introduced by a recent dw_hdmi
> change that can unwedge the dw_hdmi i2c bus in some cases.  It's
> expected that any boards using this would add:
> 
>   pinctrl-names = "default", "unwedge";
>   pinctrl-0 = <&hdmi_ddc>;
>   pinctrl-1 = <&hdmi_ddc_unwedge>;
> 
> Note that this isn't added by default because some boards may choose
> to mux i2c5 for their DDC bus (if that is more tested for them).
> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Reviewed-by: Sean Paul <sean@poorly.run>

> ---
> 
>  arch/arm/boot/dts/rk3288.dtsi | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/rk3288.dtsi b/arch/arm/boot/dts/rk3288.dtsi
> index 74c9517c4f92..eebc04fa1e4d 100644
> --- a/arch/arm/boot/dts/rk3288.dtsi
> +++ b/arch/arm/boot/dts/rk3288.dtsi
> @@ -1545,6 +1545,15 @@
>  				rockchip,pins = <7 RK_PC3 2 &pcfg_pull_none>,
>  						<7 RK_PC4 2 &pcfg_pull_none>;
>  			};
> +
> +			hdmi_ddc_unwedge: hdmi-ddc-unwedge {
> +				rockchip,pins = <7 RK_PC3 RK_FUNC_GPIO &pcfg_output_low>,
> +						<7 RK_PC4 2 &pcfg_pull_none>;
> +			};
> +		};
> +
> +		pcfg_output_low: pcfg-output-low {
> +			output-low;
>  		};
>  
>  		pcfg_pull_up: pcfg-pull-up {
> -- 
> 2.21.0.1020.gf2820cf01a-goog
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS

Re: [PATCH 5/5] ARM: dts: rockchip: Add HDMI i2c unwedging for rk3288-veyron

[Sean Paul]

On Thu, May 02, 2019 at 03:53:36PM -0700, Douglas Anderson wrote:
> Veyron uses the builtin i2c controller that's part of dw-hdmi.  Hook
> up the unwedging feature.
> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

Reviewed-by: Sean Paul <sean@poorly.run>

> ---
> 
>  arch/arm/boot/dts/rk3288-veyron.dtsi | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/rk3288-veyron.dtsi b/arch/arm/boot/dts/rk3288-veyron.dtsi
> index e1bee663d2c5..340b276b6333 100644
> --- a/arch/arm/boot/dts/rk3288-veyron.dtsi
> +++ b/arch/arm/boot/dts/rk3288-veyron.dtsi
> @@ -163,8 +163,9 @@
>  };
>  
>  &hdmi {
> -	pinctrl-names = "default";
> +	pinctrl-names = "default", "unwedge";
>  	pinctrl-0 = <&hdmi_ddc>;
> +	pinctrl-1 = <&hdmi_ddc_unwedge>;
>  	status = "okay";
>  };
>  
> -- 
> 2.21.0.1020.gf2820cf01a-goog
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS

Re: [PATCH 1/5] dt-bindings: drm/bridge/synopsys: dw-hdmi: Add "unwedge" for ddc bus

[Sean Paul]

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

Re: [PATCH 3/5] ARM: dts: rockchip: Switch to builtin HDMI DDC bus on rk3288-veyron

[Heiko Stuebner]

Am Freitag, 3. Mai 2019, 00:53:34 CEST schrieb Douglas Anderson:
> Downstream Chrome OS kernels use the builtin DDC bus from dw_hdmi on
> veyron.  This is the only way to get them to negotiate HDCP.
> 
> Although HDCP isn't currently all supported upstream, it still seems
> like it makes sense to use dw_hdmi's builtin I2C.  Maybe eventually we
> can get HDCP negotiation working.
> 
> Signed-off-by: Douglas Anderson <dianders@chromium.org>

applied patches 3 to 5 for 5.3

Thanks
Heiko