| Message ID | 20220622173605.1168416-7-pmalani@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | usb: typec: Introduce typec-switch binding | expand |
Quoting Prashant Malani (2022-06-22 10:34:35) > From: Pin-Yen Lin <treapking@chromium.org> > > ITE IT6505 can be used in systems to switch USB Type-C DisplayPort > alternate mode lane traffic between 2 Type-C ports. How does it work? From what I can tell from the information I find when googling this part[1] and looking at the existing binding doc is that this device is a DPI to DP bridge, and it outputs DP (probably 4 lanes of it?). Does the 2 type-c port design work by transmitting DP on two lanes of DP for one type-c port and another two lanes of DP for the other type-c port? DP could be one lane, so if this device is able to output one lane on any output differential pair then I suspect it could support 4 type-c ports if the hardware engineer connected it that way. Can you confirm my suspicion? [1] https://www.ite.com.tw/en/product/view?mid=45
On Thu, Jun 23, 2022 at 11:24 AM Stephen Boyd <swboyd@chromium.org> wrote: > > Quoting Prashant Malani (2022-06-22 10:34:35) > > From: Pin-Yen Lin <treapking@chromium.org> > > > > ITE IT6505 can be used in systems to switch USB Type-C DisplayPort > > alternate mode lane traffic between 2 Type-C ports. > > How does it work? From what I can tell from the information I find when > googling this part[1] and looking at the existing binding doc is that > this device is a DPI to DP bridge, and it outputs DP (probably 4 lanes > of it?). Does the 2 type-c port design work by transmitting DP on two > lanes of DP for one type-c port and another two lanes of DP for the > other type-c port? > > DP could be one lane, so if this device is able to output one lane on > any output differential pair then I suspect it could support 4 type-c > ports if the hardware engineer connected it that way. Can you confirm my > suspicion? I will let Pin-Yen comment re: this hardware, but 1-lane DP is not a supported Type-C Pin assignment (as per VESA DP Alternate Mode Spec version 2.0 [2]), so the H/W configuration you are suggesting shouldn't be possible. > > [1] https://www.ite.com.tw/en/product/view?mid=45
Quoting Prashant Malani (2022-06-23 11:37:08) > On Thu, Jun 23, 2022 at 11:24 AM Stephen Boyd <swboyd@chromium.org> wrote: > > > > Quoting Prashant Malani (2022-06-22 10:34:35) > > > From: Pin-Yen Lin <treapking@chromium.org> > > > > > > ITE IT6505 can be used in systems to switch USB Type-C DisplayPort > > > alternate mode lane traffic between 2 Type-C ports. > > > > How does it work? From what I can tell from the information I find when > > googling this part[1] and looking at the existing binding doc is that > > this device is a DPI to DP bridge, and it outputs DP (probably 4 lanes > > of it?). Does the 2 type-c port design work by transmitting DP on two > > lanes of DP for one type-c port and another two lanes of DP for the > > other type-c port? > > > > DP could be one lane, so if this device is able to output one lane on > > any output differential pair then I suspect it could support 4 type-c > > ports if the hardware engineer connected it that way. Can you confirm my > > suspicion? > > I will let Pin-Yen comment re: this hardware, but 1-lane DP is not a > supported Type-C Pin assignment > (as per VESA DP Alternate Mode Spec version 2.0 [2]), so the H/W Some missing link? > configuration you are suggesting shouldn't be possible. > Alright, cool. But it is possible in the DP spec. So it seems like if this is connected to 4 DP connectors it could be used to mux between DP on 4 DP ports.
On Thu, Jun 23, 2022 at 12:08 PM Stephen Boyd <swboyd@chromium.org> wrote: > > Quoting Prashant Malani (2022-06-23 11:37:08) > > On Thu, Jun 23, 2022 at 11:24 AM Stephen Boyd <swboyd@chromium.org> wrote: > > > > > > Quoting Prashant Malani (2022-06-22 10:34:35) > > > > From: Pin-Yen Lin <treapking@chromium.org> > > > > > > > > ITE IT6505 can be used in systems to switch USB Type-C DisplayPort > > > > alternate mode lane traffic between 2 Type-C ports. > > > > > > How does it work? From what I can tell from the information I find when > > > googling this part[1] and looking at the existing binding doc is that > > > this device is a DPI to DP bridge, and it outputs DP (probably 4 lanes > > > of it?). Does the 2 type-c port design work by transmitting DP on two > > > lanes of DP for one type-c port and another two lanes of DP for the > > > other type-c port? > > > > > > DP could be one lane, so if this device is able to output one lane on > > > any output differential pair then I suspect it could support 4 type-c > > > ports if the hardware engineer connected it that way. Can you confirm my > > > suspicion? > > > > I will let Pin-Yen comment re: this hardware, but 1-lane DP is not a > > supported Type-C Pin assignment > > (as per VESA DP Alternate Mode Spec version 2.0 [2]), so the H/W > > Some missing link? My bad. I tried to find a publicly accessible link to the DP altmode spec, but it seems like one needs to be a VESA member to access it :/ > > > configuration you are suggesting shouldn't be possible. > > > > Alright, cool. But it is possible in the DP spec. So it seems like if > this is connected to 4 DP connectors it could be used to mux between DP > on 4 DP ports. Ack. In that case, no "typec-switches" should be added to the DT.
diff --git a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml index 833d11b2303a..86bb6dc5ae6f 100644 --- a/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6505.yaml @@ -56,13 +56,46 @@ properties: $ref: /schemas/graph.yaml#/properties/port description: A port node pointing to DPI host port node + switches: + type: object + description: Set of switches controlling DisplayPort traffic on + outgoing RX/TX lanes to Type C ports. + additionalProperties: false + + properties: + '#address-cells': + const: 1 + + '#size-cells': + const: 0 + + patternProperties: + '^switch@[01]$': + $ref: /schemas/usb/typec-switch.yaml# + unevaluatedProperties: false + + properties: + reg: + maxItems: 1 + + required: + - reg + + required: + - switch@0 + required: - compatible - ovdd-supply - pwr18-supply - interrupts - reset-gpios - - extcon + +oneOf: + - required: + - extcon + - required: + - switches additionalProperties: false @@ -92,3 +125,65 @@ examples: }; }; }; + - | + #include <dt-bindings/interrupt-controller/irq.h> + + i2c3 { + #address-cells = <1>; + #size-cells = <0>; + + it6505dptx: it6505dptx@5c { + compatible = "ite,it6505"; + interrupts = <8 IRQ_TYPE_LEVEL_LOW 8 0>; + reg = <0x5c>; + pinctrl-names = "default"; + pinctrl-0 = <&it6505_pins>; + ovdd-supply = <&mt6366_vsim2_reg>; + pwr18-supply = <&pp1800_dpbrdg_dx>; + reset-gpios = <&pio 177 0>; + + port { + it6505_dp_in: endpoint { + remote-endpoint = <&dpi_out>; + }; + }; + + switches { + #address-cells = <1>; + #size-cells = <0>; + switch@0 { + compatible = "typec-switch"; + reg = <0>; + mode-switch; + + ports { + #address-cells = <1>; + #size-cells = <0>; + port@0 { + reg = <0>; + ite_typec0: endpoint { + remote-endpoint = <&typec_port0>; + }; + }; + }; + }; + + switch@1 { + compatible = "typec-switch"; + reg = <1>; + mode-switch; + + ports { + #address-cells = <1>; + #size-cells = <0>; + port@0 { + reg = <0>; + ite_typec1: endpoint { + remote-endpoint = <&typec_port1>; + }; + }; + }; + }; + }; + }; + };