[PATCH v2] riscv: dts: spacemit: add UART resets for Soc K1

Yixun Lan dlan at gentoo.org
Thu Aug 21 15:04:30 PDT 2025


On 17:26 Thu 21 Aug     , Hendrik Hamerlinck wrote:
> The UARTs in the SpacemiT K1 device tree are probed by the 8250_of driver,
> but without reset lines they remain non-functional.
> 
> Add reset control entries so that the UARTs can operate when mapped to
> devices. UART0 is already de-asserted by the bootloader, but include its
> reset as well to avoid relying on bootloader state.
> 
> Tested on Orange Pi RV2 and Banana Pi BPI-F3 boards, with UART9 enabled
> and verified functional.
> 
> Signed-off-by: Hendrik Hamerlinck <hendrik.hamerlinck at hammernet.be>

Reviewed-by: Yixun Lan <dlan at gentoo.org>
> ---
> Changes in v2:
> - Improved changelog
> - Omitted current-speed property for UART0
> ---
>  arch/riscv/boot/dts/spacemit/k1.dtsi | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/riscv/boot/dts/spacemit/k1.dtsi b/arch/riscv/boot/dts/spacemit/k1.dtsi
> index abde8bb07c95..6c68b2e54675 100644
> --- a/arch/riscv/boot/dts/spacemit/k1.dtsi
> +++ b/arch/riscv/boot/dts/spacemit/k1.dtsi
> @@ -667,6 +667,7 @@ uart0: serial at d4017000 {
>  				clocks = <&syscon_apbc CLK_UART0>,
>  					 <&syscon_apbc CLK_UART0_BUS>;
>  				clock-names = "core", "bus";
> +				resets = <&syscon_apbc RESET_UART0>;
>  				interrupts = <42>;
>  				reg-shift = <2>;
>  				reg-io-width = <4>;
> @@ -680,6 +681,7 @@ uart2: serial at d4017100 {
>  				clocks = <&syscon_apbc CLK_UART2>,
>  					 <&syscon_apbc CLK_UART2_BUS>;
>  				clock-names = "core", "bus";
> +				resets = <&syscon_apbc RESET_UART2>;
>  				interrupts = <44>;
>  				reg-shift = <2>;
>  				reg-io-width = <4>;
> @@ -693,6 +695,7 @@ uart3: serial at d4017200 {
>  				clocks = <&syscon_apbc CLK_UART3>,
>  					 <&syscon_apbc CLK_UART3_BUS>;
>  				clock-names = "core", "bus";
> +				resets = <&syscon_apbc RESET_UART3>;
>  				interrupts = <45>;
>  				reg-shift = <2>;
>  				reg-io-width = <4>;
> @@ -706,6 +709,7 @@ uart4: serial at d4017300 {
>  				clocks = <&syscon_apbc CLK_UART4>,
>  					 <&syscon_apbc CLK_UART4_BUS>;
>  				clock-names = "core", "bus";
> +				resets = <&syscon_apbc RESET_UART4>;
>  				interrupts = <46>;
>  				reg-shift = <2>;
>  				reg-io-width = <4>;
> @@ -719,6 +723,7 @@ uart5: serial at d4017400 {
>  				clocks = <&syscon_apbc CLK_UART5>,
>  					 <&syscon_apbc CLK_UART5_BUS>;
>  				clock-names = "core", "bus";
> +				resets = <&syscon_apbc RESET_UART5>;
>  				interrupts = <47>;
>  				reg-shift = <2>;
>  				reg-io-width = <4>;
> @@ -732,6 +737,7 @@ uart6: serial at d4017500 {
>  				clocks = <&syscon_apbc CLK_UART6>,
>  					 <&syscon_apbc CLK_UART6_BUS>;
>  				clock-names = "core", "bus";
> +				resets = <&syscon_apbc RESET_UART6>;
>  				interrupts = <48>;
>  				reg-shift = <2>;
>  				reg-io-width = <4>;
> @@ -745,6 +751,7 @@ uart7: serial at d4017600 {
>  				clocks = <&syscon_apbc CLK_UART7>,
>  					 <&syscon_apbc CLK_UART7_BUS>;
>  				clock-names = "core", "bus";
> +				resets = <&syscon_apbc RESET_UART7>;
>  				interrupts = <49>;
>  				reg-shift = <2>;
>  				reg-io-width = <4>;
> @@ -758,6 +765,7 @@ uart8: serial at d4017700 {
>  				clocks = <&syscon_apbc CLK_UART8>,
>  					 <&syscon_apbc CLK_UART8_BUS>;
>  				clock-names = "core", "bus";
> +				resets = <&syscon_apbc RESET_UART8>;
>  				interrupts = <50>;
>  				reg-shift = <2>;
>  				reg-io-width = <4>;
> @@ -771,6 +779,7 @@ uart9: serial at d4017800 {
>  				clocks = <&syscon_apbc CLK_UART9>,
>  					 <&syscon_apbc CLK_UART9_BUS>;
>  				clock-names = "core", "bus";
> +				resets = <&syscon_apbc RESET_UART9>;
>  				interrupts = <51>;
>  				reg-shift = <2>;
>  				reg-io-width = <4>;
> -- 
> 2.43.0
> 

-- 
Yixun Lan (dlan)



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