On Thu, Dec 19, 2024 at 08:25:31AM +0100, Ahmad Fatoum wrote:
> uart1 TX, RX and RTS signals go off the base board and to a RS485
> transceiver. Describe this in the device tree.
Look like it is not related what your did in this patch.
Add uart-has-rtscts in uart1 to ... (because ....)
Frank
>
> Signed-off-by: Ahmad Fatoum <a.fatoum@xxxxxxxxxxxxxx>
> ---
> arch/arm64/boot/dts/freescale/imx8mp-skov-reva.dtsi | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mp-skov-reva.dtsi b/arch/arm64/boot/dts/freescale/imx8mp-skov-reva.dtsi
> index 7ae686d37dda..bce23d62cd27 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mp-skov-reva.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mp-skov-reva.dtsi
> @@ -404,6 +404,13 @@ &uart1 {
> pinctrl-names = "default";
> pinctrl-0 = <&pinctrl_uart1>;
> status = "okay";
> + /*
> + * While there is no CTS line, the property "uart-has-rtscts" is still
> + * the right thing to do to enable the UART to do RS485. In RS485-Mode
> + * CTS isn't used anyhow and there is no dedicated property
> + * "uart-has-rts-but-no-cts".
> + */
> + uart-has-rtscts;
> };
>
> &uart2 {
> @@ -618,6 +625,8 @@ pinctrl_uart1: uart1grp {
> MX8MP_IOMUXC_UART1_RXD__UART1_DCE_RX 0x140
> MX8MP_IOMUXC_UART1_TXD__UART1_DCE_TX 0x140
> MX8MP_IOMUXC_UART3_RXD__UART1_DTE_RTS 0x140
> + /* CTS pin is not connected, but needed as workaround */
what' means here! what's problem to be workaround?
> + MX8MP_IOMUXC_UART3_TXD__UART1_DTE_CTS 0x140
> >;
> };
>
>
> --
> 2.39.5
>
