[PATCH v4 15/18] dt-bindings: usb: Add ports to google,cros-ec-typec for DP altmode
Dmitry Baryshkov
dmitry.baryshkov at linaro.org
Fri Sep 20 09:38:53 UTC 2024
On Sat, Aug 31, 2024 at 09:06:53PM GMT, Stephen Boyd wrote:
> Add a DT graph binding to google,cros-ec-typec so that it can combine
> DisplayPort (DP) and USB SuperSpeed (SS) data into a USB type-c endpoint
> that is connected to the usb-c-connector node's SS endpoint. This also
> allows us to connect the DP and USB nodes in the graph to the USB type-c
> connectors, providing the full picture of the USB type-c data flows in
> the system.
>
> Allow there to be multiple typec nodes underneath the EC node so that
> one DT graph exists per DP bridge. The EC is actually controlling TCPCs
> and redrivers that combine the DP and USB signals together so this more
> accurately reflects the hardware design without introducing yet another
> DT node underneath the EC for USB type-c.
>
> If the type-c ports are being shared between a single DP controller then
> the ports need to know about each other and determine a policy to drive
> DP to one type-c port. If the type-c ports each have their own dedicated
> DP controller then they're able to operate independently and enter/exit
> DP altmode independently as well. We can't connect the DP controller's
> endpoint to one usb-c-connector port at 1 endpoint and the USB controller's
> endpoint to another usb-c-connector port at 1 endpoint either because the
> DP muxing case would have DP connected to two usb-c-connector endpoints
> which the graph binding doesn't support.
>
> Therefore, one typec node is required per the capabilities of the type-c
> port(s) being managed. This also lets us indicate which type-c ports the
> DP controller is wired to. For example, if DP was connected to ports 0
> and 2, while port 1 was connected to another DP controller we wouldn't
> be able to implement that without having some other DT property to
> indicate which output ports are connected to the DP endpoint.
Based on our disccusions at LPC, here are several DT examples that seem
sensible to implement this case and several related cases from other
ChromeBooks.
typec {
compatible = "google,cros-ec-typec";
port {
typec_dp_in: endpoint {
remote-endpoint = <&usb_1_qmp_phy_out_dp>;
};
};
usb_c0: connector at 0 {
compatible = "usb-c-connector";
reg = <0>;
ports {
port at 0 {
reg = <0>;
usb_c0_hs_in: endpoint {
remote-endpoint = <&usb_hub_dfp1_hs>;
};
};
port at 1 {
reg = <1>;
usb_c0_ss_in: endpoint {
remote-endpoint = <&usb_hub_dfp1_ss>;
};
};
};
};
usb_c1: connector at 1 {
compatible = "usb-c-connector";
reg = <1>;
ports {
port at 0 {
reg = <0>;
usb_c1_hs_in: endpoint {
remote-endpoint = <&usb_hub_dfp2_hs>;
};
};
port at 1 {
reg = <1>;
usb_c1_ss_in: endpoint {
remote-endpoint = <&usb_hub_dfp2_ss>;
};
};
};
};
};
&usb_1_qmpphy {
ports {
port at 0 {
endpoint at 0 {
data-lanes = <0 1>;
// this might go to USB-3 hub
};
usb_1_qmp_phy_out_dp: endpoint at 1 {
remote-endpoint = <&typec_dp_in>;
data-lanes = <2 3>;
};
}
};
};
-------
typec {
connector at 0 {
port at 1 {
endpoint at 0 {
remtoe = <&usb_hub_0>;
};
endpoint at 1 {
remote = <&dp_bridge_out_0>;
};
};
};
connector at 1 {
port at 1 {
endpoint at 0 {
remtoe = <&usb_hub_1>;
};
endpoint at 1 {
remote = <&dp_bridge_out_1>;
};
};
};
};
dp_bridge {
ports {
port at 1 {
dp_bridge_out_0: endpoint at 0 {
remote = <usb_c0_ss_dp>;
data-lanes = <0 1>;
};
dp_bridge_out_1: endpoint at 1 {
remote = <usb_c1_ss_dp>;
data-lanes = <2 3>;
};
};
};
};
-------
This one is really tough example, we didn't reach a conclusion here.
If the EC doesn't handle lane remapping, dp_bridge has to get
orientation-switch and mode-switch properties (as in the end it is the
dp_bridge that handles reshuffling of the lanes for the Type-C). Per the
DisplayPort standard the lanes are fixed (e.g. DPCD 101h explicitly
names lane 0, lanes 0-1, lanes 0-1-2-3).
typec {
connector at 0 {
port at 1 {
endpoint at 0 {
remtoe = <&usb_hub_0>;
};
endpoint at 1 {
remote = <&dp_bridge_out_0>;
};
};
};
};
dp_bridge {
orientation-switch;
mode-switch;
ports {
port at 1 {
dp_bridge_out_0: endpoint {
remote = <usb_c0_ss_dp>;
data-lanes = <0 1 2 3>;
};
};
};
};
-------
> Reviewed-by: Rob Herring (Arm) <robh at kernel.org>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt at linaro.org>
> Cc: Conor Dooley <conor+dt at kernel.org>
> Acked-by: Lee Jones <lee at kernel.org>
> Cc: Benson Leung <bleung at chromium.org>
> Cc: Guenter Roeck <groeck at chromium.org>
> Cc: Prashant Malani <pmalani at chromium.org>
> Cc: Tzung-Bi Shih <tzungbi at kernel.org>
> Cc: <devicetree at vger.kernel.org>
> Cc: <chrome-platform at lists.linux.dev>
> Cc: Pin-yen Lin <treapking at chromium.org>
> Signed-off-by: Stephen Boyd <swboyd at chromium.org>
> ---
> .../bindings/mfd/google,cros-ec.yaml | 7 +-
> .../bindings/usb/google,cros-ec-typec.yaml | 229 ++++++++++++++++++
> 2 files changed, 233 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
> index c991626dc22b..bbe28047d0c0 100644
> --- a/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
> +++ b/Documentation/devicetree/bindings/mfd/google,cros-ec.yaml
> @@ -98,9 +98,6 @@ properties:
>
> gpio-controller: true
>
> - typec:
> - $ref: /schemas/usb/google,cros-ec-typec.yaml#
> -
> ec-pwm:
> $ref: /schemas/pwm/google,cros-ec-pwm.yaml#
> deprecated: true
> @@ -166,6 +163,10 @@ patternProperties:
> type: object
> $ref: /schemas/extcon/extcon-usbc-cros-ec.yaml#
>
> + "^typec(-[0-9])*$":
> + type: object
> + $ref: /schemas/usb/google,cros-ec-typec.yaml#
> +
> required:
> - compatible
>
> diff --git a/Documentation/devicetree/bindings/usb/google,cros-ec-typec.yaml b/Documentation/devicetree/bindings/usb/google,cros-ec-typec.yaml
> index 365523a63179..235b86da3cdd 100644
> --- a/Documentation/devicetree/bindings/usb/google,cros-ec-typec.yaml
> +++ b/Documentation/devicetree/bindings/usb/google,cros-ec-typec.yaml
> @@ -26,6 +26,106 @@ properties:
> '#size-cells':
> const: 0
>
> + mux-gpios:
> + description: GPIOs indicating which way the DP mux is steered
> + maxItems: 1
> +
> + no-hpd:
> + description: Indicates this endpoint doesn't signal HPD for DisplayPort
> + type: boolean
> +
> + mode-switch:
> + $ref: usb-switch.yaml#properties/mode-switch
> +
> + orientation-switch:
> + $ref: usb-switch.yaml#properties/orientation-switch
> +
> + ports:
> + $ref: /schemas/graph.yaml#/properties/ports
> +
> + properties:
> + port at 0:
> + $ref: /schemas/graph.yaml#/$defs/port-base
> + unevaluatedProperties: false
> + description: Output ports for combined DP and USB SS data
> + patternProperties:
> + "^endpoint@([0-8])$":
> + $ref: usb-switch.yaml#/$defs/usbc-out-endpoint
> + unevaluatedProperties: false
> +
> + anyOf:
> + - required:
> + - endpoint at 0
> + - required:
> + - endpoint at 1
> + - required:
> + - endpoint at 2
> + - required:
> + - endpoint at 3
> + - required:
> + - endpoint at 4
> + - required:
> + - endpoint at 5
> + - required:
> + - endpoint at 6
> + - required:
> + - endpoint at 7
> + - required:
> + - endpoint at 8
> +
> + port at 1:
> + $ref: /schemas/graph.yaml#/$defs/port-base
> + unevaluatedProperties: false
> + description:
> + Input port to receive USB SuperSpeed (SS) data
> + patternProperties:
> + "^endpoint@([0-8])$":
> + $ref: usb-switch.yaml#/$defs/usbc-in-endpoint
> + unevaluatedProperties: false
> +
> + anyOf:
> + - required:
> + - endpoint at 0
> + - required:
> + - endpoint at 1
> + - required:
> + - endpoint at 2
> + - required:
> + - endpoint at 3
> + - required:
> + - endpoint at 4
> + - required:
> + - endpoint at 5
> + - required:
> + - endpoint at 6
> + - required:
> + - endpoint at 7
> + - required:
> + - endpoint at 8
> +
> + port at 2:
> + $ref: /schemas/graph.yaml#/$defs/port-base
> + description:
> + Input port to receive DisplayPort (DP) data
> + unevaluatedProperties: false
> +
> + properties:
> + endpoint:
> + $ref: usb-switch.yaml#/$defs/dp-endpoint
> + unevaluatedProperties: false
> +
> + required:
> + - endpoint
> +
> + required:
> + - port at 0
> +
> + anyOf:
> + - required:
> + - port at 1
> + - required:
> + - port at 2
> +
> patternProperties:
> '^connector@[0-9a-f]+$':
> $ref: /schemas/connector/usb-connector.yaml#
> @@ -35,6 +135,40 @@ patternProperties:
> required:
> - compatible
>
> +allOf:
> + - if:
> + required:
> + - no-hpd
> + then:
> + properties:
> + ports:
> + required:
> + - port at 2
> + - if:
> + required:
> + - mux-gpios
> + then:
> + properties:
> + ports:
> + required:
> + - port at 2
> + - if:
> + required:
> + - orientation-switch
> + then:
> + properties:
> + ports:
> + required:
> + - port at 2
> + - if:
> + required:
> + - mode-switch
> + then:
> + properties:
> + ports:
> + required:
> + - port at 2
> +
> additionalProperties: false
>
> examples:
> @@ -50,6 +184,8 @@ examples:
>
> typec {
> compatible = "google,cros-ec-typec";
> + orientation-switch;
> + mode-switch;
>
> #address-cells = <1>;
> #size-cells = <0>;
> @@ -60,6 +196,99 @@ examples:
> power-role = "dual";
> data-role = "dual";
> try-power-role = "source";
> +
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + port at 0 {
> + reg = <0>;
> + usb_c0_hs: endpoint {
> + remote-endpoint = <&usb_hub_dfp3_hs>;
> + };
> + };
> +
> + port at 1 {
> + reg = <1>;
> + usb_c0_ss: endpoint {
> + remote-endpoint = <&cros_typec_c0_ss>;
> + };
> + };
> + };
> + };
> +
> + connector at 1 {
> + compatible = "usb-c-connector";
> + reg = <1>;
> + power-role = "dual";
> + data-role = "dual";
> + try-power-role = "source";
> +
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + port at 0 {
> + reg = <0>;
> + usb_c1_hs: endpoint {
> + remote-endpoint = <&usb_hub_dfp2_hs>;
> + };
> + };
> +
> + port at 1 {
> + reg = <1>;
> + usb_c1_ss: endpoint {
> + remote-endpoint = <&cros_typec_c1_ss>;
> + };
> + };
> + };
> + };
> +
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + port at 0 {
> + reg = <0>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + cros_typec_c0_ss: endpoint at 0 {
> + reg = <0>;
> + remote-endpoint = <&usb_c0_ss>;
> + data-lanes = <0 1 2 3>;
> + };
> +
> + cros_typec_c1_ss: endpoint at 1 {
> + reg = <1>;
> + remote-endpoint = <&usb_c1_ss>;
> + data-lanes = <2 3 0 1>;
> + };
> + };
> +
> + port at 1 {
> + reg = <1>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + usb_in_0: endpoint at 0 {
> + reg = <0>;
> + remote-endpoint = <&usb_ss_0_out>;
> + };
> +
> + usb_in_1: endpoint at 1 {
> + reg = <1>;
> + remote-endpoint = <&usb_ss_1_out>;
> + };
> + };
> +
> + port at 2 {
> + reg = <2>;
> + dp_in: endpoint {
> + remote-endpoint = <&dp_phy>;
> + data-lanes = <0 1>;
> + };
> + };
> };
> };
> };
> --
> https://chromeos.dev
>
--
With best wishes
Dmitry
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