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From: Yixun Lan <dlan@gentoo.org>
To: Hendrik Hamerlinck <hendrik.hamerlinck@hammernet.be>
Cc: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org,
	paul.walmsley@sifive.com, palmer@dabbelt.com,
	aou@eecs.berkeley.edu, alex@ghiti.fr, skhan@linuxfoundation.org,
	linux-kernel-mentees@lists.linux.dev, devicetree@vger.kernel.org,
	linux-riscv@lists.infradead.org, spacemit@lists.linux.dev,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] riscv: dts: spacemit: add UART resets for Soc K1
Date: Fri, 22 Aug 2025 06:04:30 +0800	[thread overview]
Message-ID: <20250821220430-GYA1070455@gentoo> (raw)
In-Reply-To: <20250821152619.597051-1-hendrik.hamerlinck@hammernet.be>

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@hammernet.be>

Reviewed-by: Yixun Lan <dlan@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@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@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@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@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@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@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@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@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@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)

  reply	other threads:[~2025-08-21 22:04 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-08-21 15:26 [PATCH v2] riscv: dts: spacemit: add UART resets for Soc K1 Hendrik Hamerlinck
2025-08-21 22:04 ` Yixun Lan [this message]
2025-08-24  7:36 ` Yixun Lan

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