Re: [PATCH v2] arm64: dts: qcom: ipq5424: Describe the 4-wire UART SE

From: Konrad Dybcio
Date: Tue Jun 24 2025 - 10:56:54 EST


On 6/24/25 11:00 AM, Kathiravan Thirumoorthy wrote:
> QUPv3 in IPQ5424 consists of six Serial Engines (SEs). Describe the
> first SE, which supports a 4-wire UART configuration suitable for
> applications such as HS-UART.
>
> Note that the required initialization for this SE is not handled by the
> bootloader. Therefore, add the SE node in the device tree but keep it
> disabled. Enable it once Linux gains support for configuring the SE,
> allowing to use in relevant RDPs.

Do you mean fw loading support?

>
> Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@xxxxxxxxxxxxxxxx>
> ---
> Changes in v2:
> - Correct the interrupt number
> - Link to v1: https://lore.kernel.org/r/20250624-ipq5424_hsuart-v1-1-a4e71d00fc05@xxxxxxxxxxxxxxxx
> ---
> arch/arm64/boot/dts/qcom/ipq5424.dtsi | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/qcom/ipq5424.dtsi b/arch/arm64/boot/dts/qcom/ipq5424.dtsi
> index 66bd2261eb25d79051adddef604c55f5b01e6e8b..2b8499422a8a9a2f63e1af9ae8c189bafe690514 100644
> --- a/arch/arm64/boot/dts/qcom/ipq5424.dtsi
> +++ b/arch/arm64/boot/dts/qcom/ipq5424.dtsi
> @@ -417,6 +417,15 @@ qupv3: geniqup@1ac0000 {
> #address-cells = <2>;
> #size-cells = <2>;
>
> + uart0: serial@1a80000 {
> + compatible = "qcom,geni-uart";
> + reg = <0 0x01a80000 0 0x4000>;
> + clocks = <&gcc GCC_QUPV3_UART0_CLK>;
> + clock-names = "se";
> + interrupts = <GIC_SPI 339 IRQ_TYPE_LEVEL_HIGH>;
> + status = "disabled";
> + };

I'd normally expect to see a pin configuration here as well,
especially since you mention the bootloader doesn't configure
the interface

Konrad