[PATCH v2 0/4] arm64: dts: amlogic: meson-s4-khadas-vim1s: enable LEDs, Keys and Bluetooth

[PATCH v2 0/4] arm64: dts: amlogic: meson-s4-khadas-vim1s: enable LEDs, Keys and Bluetooth

[Nick Xie]

This series enables various user interfaces and the Bluetooth module
for the Khadas VIM1S board (Amlogic S905Y4).

This builds upon the existing board support to fully enable the
user-facing peripherals.

Changes in v2:
- Dropped the SARADC and Function Key patches from this series. As
  suggested by Martin Blumenstingl, a dedicated compatible string and
  driver update for the S4 SARADC will be submitted in a separate series
  to ensure forward compatibility.
- Patch 1: Split the UART_A pinctrl definitions in meson-s4.dtsi into
  separate rx/tx and rts/cts groups to keep the SoC dtsi generic
  (Martin Blumenstingl).
- Patch 2: Assigned the UART_A pinctrl groups directly in the board dts.
- Added Martin's 'Reviewed-by' tags to Patches 2, 3, and 4.
- Link to v1: https://lore.kernel.org/linux-amlogic/20260123022258.136448-1-nick@khadas.com/

Nick Xie (4):
  arm64: dts: amlogic: meson-s4: add UART_A node
  arm64: dts: amlogic: meson-s4-s905y4-khadas-vim1s: enable bluetooth
  arm64: dts: amlogic: meson-s4-s905y4-khadas-vim1s: add PWM LED support
  arm64: dts: amlogic: meson-s4-s905y4-khadas-vim1s: add POWER key
    support

 .../amlogic/meson-s4-s905y4-khadas-vim1s.dts  | 46 +++++++++++++++++++
 arch/arm64/boot/dts/amlogic/meson-s4.dtsi     | 26 +++++++++++
 2 files changed, 72 insertions(+)

-- 
2.34.1

[PATCH v2 1/4] arm64: dts: amlogic: meson-s4: add UART_A node

[Nick Xie]

Add the UART_A node and its related pinctrl definitions to the
Meson S4 SoC dtsi.

The pinctrl groups are split into basic tx/rx and flow control (cts/rts)
to allow board-level flexibility.

This interface is typically used for Bluetooth communication on
boards like the Khadas VIM1S.

Signed-off-by: Nick Xie <nick@khadas.com>
---
 arch/arm64/boot/dts/amlogic/meson-s4.dtsi | 26 +++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-s4.dtsi b/arch/arm64/boot/dts/amlogic/meson-s4.dtsi
index dfc0a30a6e61b..4a3e9ad82d280 100644
--- a/arch/arm64/boot/dts/amlogic/meson-s4.dtsi
+++ b/arch/arm64/boot/dts/amlogic/meson-s4.dtsi
@@ -163,6 +163,22 @@ mux {
 					};
 				};
 
+				uart_a_pins: uart-a-pins {
+					mux {
+						groups = "uart_a_tx",
+						       "uart_a_rx";
+						function = "uart_a";
+					};
+				};
+
+				uart_a_cts_rts_pins: uart-a-cts-rts-pins {
+					mux {
+						groups = "uart_a_cts",
+						       "uart_a_rts";
+						function = "uart_a";
+					};
+				};
+
 				i2c0_pins1: i2c0-pins1 {
 					mux {
 						groups = "i2c0_sda",
@@ -814,6 +830,16 @@ mdio0: mdio {
 			};
 		};
 
+		uart_a: serial@fe078000 {
+			compatible = "amlogic,meson-s4-uart",
+				     "amlogic,meson-ao-uart";
+			reg = <0x0 0xfe078000 0x0 0x18>;
+			interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
+			clocks = <&xtal>, <&clkc_periphs CLKID_UART_A>, <&xtal>;
+			clock-names = "xtal", "pclk", "baud";
+			status = "disabled";
+		};
+
 		sdio: mmc@fe088000 {
 			compatible = "amlogic,meson-axg-mmc";
 			reg = <0x0 0xfe088000 0x0 0x800>;
-- 
2.34.1

[PATCH v2 2/4] arm64: dts: amlogic: meson-s4-s905y4-khadas-vim1s: enable bluetooth

[Nick Xie]

The Khadas VIM1S board uses the Ampak AP6256 Wi-Fi/Bluetooth module.
The Bluetooth controller is connected via UART_A and requires the
external 32k clock (LPO).

Enable the UART_A node and add the bluetooth child node to support it.

Signed-off-by: Nick Xie <nick@khadas.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 .../dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts  | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts b/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts
index 27d0f6134ea9d..d36533f5559a8 100644
--- a/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts
+++ b/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts
@@ -254,6 +254,21 @@ &spicc0 {
 	cs-gpios = <&gpio GPIOX_10 GPIO_ACTIVE_LOW>;
 };
 
+&uart_a {
+	status = "okay";
+	pinctrl-0 = <&uart_a_pins>, <&uart_a_cts_rts_pins>;
+	pinctrl-names = "default";
+	uart-has-rtscts;
+
+	bluetooth {
+		compatible = "brcm,bcm4345c5";
+		shutdown-gpios = <&gpio GPIOX_17 GPIO_ACTIVE_HIGH>;
+		max-speed = <2000000>;
+		clocks = <&sdio_32k>;
+		clock-names = "lpo";
+	};
+};
+
 &uart_b {
 	status = "okay";
 };
-- 
2.34.1

[PATCH v2 3/4] arm64: dts: amlogic: meson-s4-s905y4-khadas-vim1s: add PWM LED support

[Nick Xie]

The Khadas VIM1S board features a white LED connected to the PWM_G
controller (PWM channel 0).

Enable the PWM_G controller and add the pwm-leds node to support
using this LED as a heartbeat indicator.

Signed-off-by: Nick Xie <nick@khadas.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 .../amlogic/meson-s4-s905y4-khadas-vim1s.dts  | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts b/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts
index d36533f5559a8..0bd738c1e7862 100644
--- a/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts
+++ b/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts
@@ -6,6 +6,7 @@
 /dts-v1/;
 
 #include "meson-s4.dtsi"
+#include <dt-bindings/leds/common.h>
 
 / {
 	model = "Khadas VIM1S";
@@ -43,6 +44,18 @@ emmc_pwrseq: emmc-pwrseq {
 		reset-gpios = <&gpio GPIOB_9 GPIO_ACTIVE_LOW>;
 	};
 
+	pwm-leds {
+		compatible = "pwm-leds";
+
+		led-1 {
+			color = <LED_COLOR_ID_WHITE>;
+			function = LED_FUNCTION_STATUS;
+			linux,default-trigger = "heartbeat";
+			max-brightness = <255>;
+			pwms = <&pwm_gh 0 30040 0>;
+		};
+	};
+
 	sdio_32k: sdio-32k {
 		compatible = "pwm-clock";
 		#clock-cells = <0>;
@@ -196,6 +209,12 @@ &pwm_ef {
 	pinctrl-names = "default";
 };
 
+&pwm_gh {
+	status = "okay";
+	pinctrl-0 = <&pwm_g_pins1>;
+	pinctrl-names = "default";
+};
+
 &pwm_ij {
 	status = "okay";
 };
-- 
2.34.1

[PATCH v2 4/4] arm64: dts: amlogic: meson-s4-s905y4-khadas-vim1s: add POWER key support

[Nick Xie]

Add the gpio-keys-polled node to support the Power button found on the
Khadas VIM1S board. The button is connected to the GPIOD_8 pin.

Use polled mode instead of gpio-keys because the GPIO interrupt
controller support for Meson S4 SoC is not yet available upstream.

Signed-off-by: Nick Xie <nick@khadas.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
---
 .../dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts     | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts b/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts
index 0bd738c1e7862..664d64a267f2d 100644
--- a/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts
+++ b/arch/arm64/boot/dts/amlogic/meson-s4-s905y4-khadas-vim1s.dts
@@ -6,6 +6,7 @@
 /dts-v1/;
 
 #include "meson-s4.dtsi"
+#include <dt-bindings/input/input.h>
 #include <dt-bindings/leds/common.h>
 
 / {
@@ -44,6 +45,17 @@ emmc_pwrseq: emmc-pwrseq {
 		reset-gpios = <&gpio GPIOB_9 GPIO_ACTIVE_LOW>;
 	};
 
+	gpio-keys-polled {
+		compatible = "gpio-keys-polled";
+		poll-interval = <100>;
+
+		power-button {
+			label = "power";
+			linux,code = <KEY_POWER>;
+			gpios = <&gpio GPIOD_8 GPIO_ACTIVE_LOW>;
+		};
+	};
+
 	pwm-leds {
 		compatible = "pwm-leds";
 
-- 
2.34.1

Re: [PATCH v2 1/4] arm64: dts: amlogic: meson-s4: add UART_A node

[Martin Blumenstingl]

On Sat, Feb 28, 2026 at 7:38 AM Nick Xie <nick@khadas.com> wrote:
>
> Add the UART_A node and its related pinctrl definitions to the
> Meson S4 SoC dtsi.
>
> The pinctrl groups are split into basic tx/rx and flow control (cts/rts)
> to allow board-level flexibility.
>
> This interface is typically used for Bluetooth communication on
> boards like the Khadas VIM1S.
>
> Signed-off-by: Nick Xie <nick@khadas.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

Re: [PATCH v2 0/4] arm64: dts: amlogic: meson-s4-khadas-vim1s: enable LEDs, Keys and Bluetooth

[Neil Armstrong]

Hi,

On Sat, 28 Feb 2026 14:37:46 +0800, Nick Xie wrote:
> This series enables various user interfaces and the Bluetooth module
> for the Khadas VIM1S board (Amlogic S905Y4).
> 
> This builds upon the existing board support to fully enable the
> user-facing peripherals.
> 
> Changes in v2:
> - Dropped the SARADC and Function Key patches from this series. As
>   suggested by Martin Blumenstingl, a dedicated compatible string and
>   driver update for the S4 SARADC will be submitted in a separate series
>   to ensure forward compatibility.
> - Patch 1: Split the UART_A pinctrl definitions in meson-s4.dtsi into
>   separate rx/tx and rts/cts groups to keep the SoC dtsi generic
>   (Martin Blumenstingl).
> - Patch 2: Assigned the UART_A pinctrl groups directly in the board dts.
> - Added Martin's 'Reviewed-by' tags to Patches 2, 3, and 4.
> - Link to v1: https://lore.kernel.org/linux-amlogic/20260123022258.136448-1-nick@khadas.com/
> 
> [...]

Thanks, Applied to https://git.kernel.org/pub/scm/linux/kernel/git/amlogic/linux.git (v7.1/arm64-dt)

[1/4] arm64: dts: amlogic: meson-s4: add UART_A node
      https://git.kernel.org/amlogic/c/6710d76d7e51a24f978eb1ae0738d1e3c25e034c
[2/4] arm64: dts: amlogic: meson-s4-s905y4-khadas-vim1s: enable bluetooth
      https://git.kernel.org/amlogic/c/ad44c753b976e469f0f014b6f92e7180b6a7ba59
[3/4] arm64: dts: amlogic: meson-s4-s905y4-khadas-vim1s: add PWM LED support
      https://git.kernel.org/amlogic/c/b8a95d4c054d9d2e784ce5eeb6a08be0ce9031d0
[4/4] arm64: dts: amlogic: meson-s4-s905y4-khadas-vim1s: add POWER key support
      https://git.kernel.org/amlogic/c/31132e11e9dd97c706434e4f9e86b503c67a6bac

These changes has been applied on the intermediate git tree [1].

The v7.1/arm64-dt branch will then be sent via a formal Pull Request to the Linux SoC maintainers
for inclusion in their intermediate git branches in order to be sent to Linus during
the next merge window, or sooner if it's a set of fixes.

In the cases of fixes, those will be merged in the current release candidate
kernel and as soon they appear on the Linux master branch they will be
backported to the previous Stable and Long-Stable kernels [2].

The intermediate git branches are merged daily in the linux-next tree [3],
people are encouraged testing these pre-release kernels and report issues on the
relevant mailing-lists.

If problems are discovered on those changes, please submit a signed-off-by revert
patch followed by a corrective changeset.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/amlogic/linux.git
[2] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
[3] https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git

-- 
Neil