Re: [PATCH v2 2/2] arm64: dts: qcom: add TP-Link Archer AX55 v1

[Gabor Juhos <j4g8y7@gmail.com>]

Hi Konrad,

2024. 03. 12. 21:37 keltezéssel, Konrad Dybcio írta:
> 
> 
> On 2/26/24 18:12, Gabor Juhos wrote:
>> Add device tree source for the TP-Link Archer AX55 v1 [1]
>> which is a dual-band WiFi router based on the IPQ5018 SoC.
>>
>> At the moment, only the UART, the GPIO LEDs and buttons
>> are usable, but it makes it possible to boot an initramfs
>> image on the device.
>>
>> The device tree can be extended in the future, once support
>> for other periherals will be available for the platform.
>>
>> 1. https://www.tp-link.com/en/home-networking/wifi-router/archer-ax55/v1/
>>
>> Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
>> ---
> 
> [...]
> 
>> +
>> +&uart1_pins {
>> +    /*
>> +     * Remove "gpio31" from the default pins in order to be able
>> +     * to use that for the WPS button.
>> +     */
>> +    pins = "gpio32", "gpio33", "gpio34";
> 
> I believe you can even shorten it down to gpio32/33, 4pin uart
> screams flow control, and I'm not sure if it's there only one-way

Thank you for the tip!

The board only uses the TX and RX lines so I have removed "gpio34" and the
console works without that.

But since I have no documentation about which GPIOs are assigned to TX and RX, I
did not stop here and checked the other two gpios as well.

The interesting thing is that the console works even if "gpio32" or "gpio33"
gets removed instead of "gpio34". It also works after the function of all three
pins being set to "gpio" instead of the current "blsp1_uart1".

This indicates that the pins are not related to UART TX/RX on this board at all.
It seems that "gpio20" and "gpio21" are used instead, and the function of those
must be set to "blsp0_uart0" even if the "blsp1_uart1" device is used.

It is quite confusing. :(

Nevertheless, I will send a new version.

Regards,
Gabor