On 25/04/23 5:31 pm, Roger Quadros wrote:
>
>
> 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.
>>
[...]
>> * 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?
>
The pin (AC9) for USB0_ID signal is not multiplexed with any other signals.
Please see Page 51 in [0].
>> + >;
>> + };
>> };
>>
[...]
>> +
>> +&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.
The SerDes on J721S2 can simultaneously support only two protocols.
By default PCIe and DP will be supported. Due to this, USB is configured
in high-speed and this does not require any SerDes lane configuration.
>
>> +};
>> +
>> &mcu_mcan0 {
>> status = "okay";
>> pinctrl-names = "default";
>
> cheers,
> -roger
[0] https://www.ti.com/lit/gpn/TDA4AL-Q1
--
Regards,
Ravi
