Re: [PATCH v14 5/8] arm64: dts: ti: k3-j721s2-common-proc-board: Add USB support

From: Roger Quadros
Date: Tue Apr 25 2023 - 08:01:25 EST




On 31/03/2023 12:00, Ravi Gunasekaran wrote:
> From: Aswath Govindraju <a-govindraju@xxxxxx>
>
> The board uses lane 1 of SERDES for USB. Set the mux
> accordingly.
>
> The USB controller and EVM supports super-speed for USB0
> on the Type-C port. However, the SERDES has a limitation
> that up to 2 protocols can be used at a time. The SERDES is
> wired for PCIe, eDP and USB super-speed. It has been
> chosen to use PCIe and eDP as default. So restrict
> USB0 to high-speed mode.
>
> Signed-off-by: Aswath Govindraju <a-govindraju@xxxxxx>
> Signed-off-by: Matt Ranostay <mranostay@xxxxxx>
> Signed-off-by: Ravi Gunasekaran <r-gunasekaran@xxxxxx>
> ---
> I had reviewed this patch in the v5 series [0].
> Since I'm taking over upstreaming this series, I removed the self
> Reviewed-by tag.
>
> [0] - https://lore.kernel.org/all/96058a13-4903-2b8c-8de2-f37fdfd3672b@xxxxxx/
>
> Changes from v13:
> * No changes. Only rebased on top of linux-next
>
> Changes from v12:
> * No change
>
> Changes from v11:
> * No change
>
> Changes from v10:
> * Removed Link tag from commit message
>
> Changes from v9:
> * Enabled USB nodes
>
> Changes from v8:
> * No change
>
> Changes from v7:
> * No change
>
> Changes from v6:
> * No change
>
> Changes from v5:
> * Removed Cc tags from commit message
>
> Changes from v4:
> * No change
>
> Changes from v3:
> * No change
>
> Changes from v2:
> * No change
>
> Changes from v1:
> * No change
>
> .../dts/ti/k3-j721s2-common-proc-board.dts | 23 +++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/ti/k3-j721s2-common-proc-board.dts b/arch/arm64/boot/dts/ti/k3-j721s2-common-proc-board.dts
> index 1afefaf3f974..5c4ffb8124ca 100644
> --- a/arch/arm64/boot/dts/ti/k3-j721s2-common-proc-board.dts
> +++ b/arch/arm64/boot/dts/ti/k3-j721s2-common-proc-board.dts
> @@ -147,6 +147,12 @@
> J721S2_IOPAD(0x020, PIN_INPUT, 7) /* (AA23) MCAN15_RX.GPIO0_8 */
> >;
> };
> +
> + main_usbss0_pins_default: main-usbss0-pins-default {
> + pinctrl-single,pins = <
> + J721S2_IOPAD(0x0ec, PIN_OUTPUT, 6) /* (AG25) TIMER_IO1.USB0_DRVVBUS */

What about USB0_ID pin?

> + >;
> + };
> };
>
> &wkup_pmx0 {
> @@ -345,6 +351,23 @@
> };
> };
>
> +&usb_serdes_mux {
> + idle-states = <1>; /* USB0 to SERDES lane 1 */
> +};
> +
> +&usbss0 {
> + status = "okay";
> + pinctrl-0 = <&main_usbss0_pins_default>;
> + pinctrl-names = "default";
> + ti,vbus-divider;
> + ti,usb2-only;
> +};
> +
> +&usb0 {
> + dr_mode = "otg";
> + maximum-speed = "high-speed";

Why is super-speed not possible?
I understood that SERDES lane 1 can be used for USB super-speed.

> +};
> +
> &mcu_mcan0 {
> status = "okay";
> pinctrl-names = "default";

cheers,
-roger