[PATCH v3 0/2] Add Samsung Galaxy A21s support

[PATCH v3 0/2] Add Samsung Galaxy A21s support

[Thomas Turner]

Hi all,

This is a small patch series which adds support to the Samsung Galaxy
A21s. This device is part of the Exynos850 SoC and its device tree is
very loosely based on the e850-95 one.

Thomas Turner (2):
  dt-bindings: arm: samsung: Add compatible for Samsung Galaxy A21s
    (SM-A217F)
  arm64: dts: exynos: Add initial support for Samsung Galaxy A21s
    (SM-A217F)

 .../bindings/arm/samsung/samsung-boards.yaml  |   1 +
 arch/arm64/boot/dts/exynos/Makefile           |   1 +
 .../arm64/boot/dts/exynos/exynos850-a217f.dts | 200 ++++++++++++++++++
 arch/arm64/boot/dts/exynos/exynos850.dtsi     |   2 +-
 4 files changed, 203 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/boot/dts/exynos/exynos850-a217f.dts

-- 
2.47.3

[PATCH v3 1/2] dt-bindings: arm: samsung: Add compatible for Samsung Galaxy A21s (SM-A217F)

[Thomas Turner]

Add binding for the Samsung Galaxy A21s (SM-A217F) board, which is
based on the Samsung Exynos850 SoC.

Signed-off-by: Thomas Turner <tturner@lineageos.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
---
Changes in v3:
 - Add Reviewed-by tag

Changes in v2:
 - Sort via alphabetical order

 .../devicetree/bindings/arm/samsung/samsung-boards.yaml          | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/arm/samsung/samsung-boards.yaml b/Documentation/devicetree/bindings/arm/samsung/samsung-boards.yaml
index 273464400477..db19a686f490 100644
--- a/Documentation/devicetree/bindings/arm/samsung/samsung-boards.yaml
+++ b/Documentation/devicetree/bindings/arm/samsung/samsung-boards.yaml
@@ -232,6 +232,7 @@ properties:
       - description: Exynos850 based boards
         items:
           - enum:
+              - samsung,a217f                   # Samsung Galaxy A21s (SM-A217F)
               - winlink,e850-96                 # WinLink E850-96
           - const: samsung,exynos850
 
-- 
2.47.3

[PATCH v3 2/2] arm64: dts: exynos: Add initial support for Samsung Galaxy A21s (SM-A217F)

[Thomas Turner]

Add initial support for the Samsung Galaxy A21s (a21s) phone. It was
launched in 2020, and it's based on the Exynos 850 SoC. It has multiple
RAM configurations: 3GB, 4GB and 6GB.

Since our bootloader does not set up memory nodes beforehand, default to
the 3GB variant. Custom bootloaders can be used to initialise other
nodes per RAM configuration.

The Exynos DPU clocks required by simple-framebuffer are not kept
enabled during boot. Add the DECON, DMA, DPP, PPMU and SSMU DPU clocks
to the simple-framebuffer node so simpledrm maintains references to
them. Without these clocks, the framebuffer fails to remain operational
further into boot.

This device tree adds support for the following:

- SimpleFB
- Buttons
- 3GB RAM
- Ramoops
- GPU
- MMC
- USB
- Watchdog

Signed-off-by: Thomas Turner <tturner@lineageos.org>
---
Changes in v3:
 - Add gpu node with dummy regulator
 - Re-order feature list in patch msg and mention GPU
 - Rebase patch on top of for-next

Changes in v2:
 - Re-order properties/nodes to pass dt-check-style --mode strict

 arch/arm64/boot/dts/exynos/Makefile           |   1 +
 .../arm64/boot/dts/exynos/exynos850-a217f.dts | 200 ++++++++++++++++++
 arch/arm64/boot/dts/exynos/exynos850.dtsi     |   2 +-
 3 files changed, 202 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm64/boot/dts/exynos/exynos850-a217f.dts

diff --git a/arch/arm64/boot/dts/exynos/Makefile b/arch/arm64/boot/dts/exynos/Makefile
index 8c48ce2e02e5..7534b773d28f 100644
--- a/arch/arm64/boot/dts/exynos/Makefile
+++ b/arch/arm64/boot/dts/exynos/Makefile
@@ -13,6 +13,7 @@ dtb-$(CONFIG_ARCH_EXYNOS) += \
 	exynos7870-j7xelte.dtb		\
 	exynos7870-on7xelte.dtb		\
 	exynos7885-jackpotlte.dtb	\
+	exynos850-a217f.dtb		\
 	exynos850-e850-96.dtb		\
 	exynos8855-smdk.dtb		\
 	exynos8895-dreamlte.dtb		\
diff --git a/arch/arm64/boot/dts/exynos/exynos850-a217f.dts b/arch/arm64/boot/dts/exynos/exynos850-a217f.dts
new file mode 100644
index 000000000000..b5b66c015e1e
--- /dev/null
+++ b/arch/arm64/boot/dts/exynos/exynos850-a217f.dts
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Samsung Galaxy A21s (a21s/SM-A217F) device tree source
+ *
+ * Copyright (c) 2026, Thomas Turner <tturner@lineageos.org>
+ */
+
+/dts-v1/;
+#include "exynos850.dtsi"
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	model = "Samsung Galaxy A21s";
+	compatible = "samsung,a217f", "samsung,exynos850";
+
+	chosen {
+		ranges;
+		#address-cells = <2>;
+		#size-cells = <1>;
+
+		framebuffer0: framebuffer@fa000000 {
+			compatible = "simple-framebuffer";
+			reg = <0x0 0xfa000000 (720 * 1600 * 4)>;
+			width = <720>;
+			height = <1600>;
+			stride = <(720 * 4)>;
+			format = "a8r8g8b8";
+			clocks = <&cmu_dpu CLK_GOUT_DPU_DECON0_ACLK>,
+				 <&cmu_dpu CLK_GOUT_DPU_DMA_ACLK>,
+				 <&cmu_dpu CLK_GOUT_DPU_DPP_ACLK>,
+				 <&cmu_dpu CLK_GOUT_DPU_PPMU_ACLK>,
+				 <&cmu_dpu CLK_GOUT_DPU_PPMU_PCLK>,
+				 <&cmu_dpu CLK_GOUT_DPU_SMMU_CLK>;
+		};
+	};
+
+	/*
+	 * RTC clock (XrtcXTI); external, must be 32.768 kHz.
+	 *
+	 * TODO: Remove this once RTC clock is implemented properly as part of
+	 *       PMIC driver.
+	 */
+	rtcclk: clock-rtcclk {
+		compatible = "fixed-clock";
+		clock-output-names = "rtcclk";
+		#clock-cells = <0>;
+		clock-frequency = <32768>;
+	};
+
+	gpio-keys {
+		compatible = "gpio-keys";
+		pinctrl-0 = <&key_voldown &key_volup>;
+		pinctrl-names = "default";
+
+		voldown-key {
+			label = "Volume Down";
+			gpios = <&gpa1 0 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_VOLUMEDOWN>;
+		};
+
+		volup-key {
+			label = "Volume Up";
+			gpios = <&gpa0 7 GPIO_ACTIVE_LOW>;
+			linux,code = <KEY_VOLUMEUP>;
+		};
+	};
+
+	memory@80000000 {
+		device_type = "memory";
+		reg = <0x0 0x80000000 0x3c900000>,
+		      <0x0 0xc0000000 0x20000000>,
+		      <0x0 0xe0d00000 0x1f300000>,
+		      <0x8 0x80000000 0x20000000>,
+		      <0x8 0xa0000000 0x20000000>;
+	};
+
+	/* TODO: Remove this once PMIC is implemented  */
+	reg_dummy: regulator-0 {
+		compatible = "regulator-fixed";
+		regulator-name = "dummy_reg";
+	};
+
+	reserved-memory {
+		ranges;
+		#address-cells = <2>;
+		#size-cells = <1>;
+
+		ramoops@f0000000 {
+			compatible = "ramoops";
+			reg = <0x0 0xf0000000 0x200000>;
+			record-size = <0x20000>;
+			console-size = <0x20000>;
+			ftrace-size = <0x100000>;
+			pmsg-size = <0x20000>;
+		};
+
+		cont_splash_mem: framebuffer@fa000000 {
+			reg = <0x0 0xfa000000 (720 * 1600 * 4)>;
+			no-map;
+		};
+	};
+};
+
+&cmu_hsi {
+	clocks = <&oscclk>, <&rtcclk>,
+		 <&cmu_top CLK_DOUT_HSI_BUS>,
+		 <&cmu_top CLK_DOUT_HSI_MMC_CARD>,
+		 <&cmu_top CLK_DOUT_HSI_USB20DRD>;
+	clock-names = "oscclk", "rtcclk", "dout_hsi_bus",
+		      "dout_hsi_mmc_card", "dout_hsi_usb20drd";
+};
+
+&gpu {
+	mali-supply = <&reg_dummy>;
+
+	status = "okay";
+};
+
+&mmc_0 {
+	compatible = "samsung,exynos7-dw-mshc";
+	mmc-hs200-1_8v;
+	mmc-hs400-1_8v;
+	cap-mmc-highspeed;
+	non-removable;
+	mmc-hs400-enhanced-strobe;
+	card-detect-delay = <200>;
+	clock-frequency = <800000000>;
+	bus-width = <8>;
+
+	pinctrl-0 = <&sd0_clk_pins &sd0_cmd_pins &sd0_rdqs_pins &sd0_nreset_pins
+		     &sd0_bus1_pins &sd0_bus4_pins &sd0_bus8_pins>;
+	pinctrl-names = "default";
+
+	samsung,dw-mshc-ciu-div = <3>;
+	samsung,dw-mshc-sdr-timing = <0 4>;
+	samsung,dw-mshc-ddr-timing = <2 4>;
+	samsung,dw-mshc-hs400-timing = <0 2>;
+
+	status = "okay";
+};
+
+&oscclk {
+	clock-frequency = <26000000>;
+};
+
+&pinctrl_alive {
+	key_voldown: key-voldown-pins {
+		samsung,pins = "gpa1-0";
+		samsung,pin-function = <EXYNOS_PIN_FUNC_EINT>;
+		samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
+		samsung,pin-drv = <EXYNOS5420_PIN_DRV_LV1>;
+	};
+
+	key_volup: key-volup-pins {
+		samsung,pins = "gpa0-7";
+		samsung,pin-function = <EXYNOS_PIN_FUNC_EINT>;
+		samsung,pin-pud = <EXYNOS_PIN_PULL_NONE>;
+		samsung,pin-drv = <EXYNOS5420_PIN_DRV_LV1>;
+	};
+};
+
+&rtc {
+	clocks = <&cmu_apm CLK_GOUT_RTC_PCLK>, <&rtcclk>;
+	clock-names = "rtc", "rtc_src";
+
+	status = "disabled";
+};
+
+&timer {
+	/*
+	 * Non-updatable, broken stock Samsung bootloader does not
+	 * configure CNTFRQ_EL0
+	 */
+	clock-frequency = <26000000>;
+};
+
+&usbdrd {
+	vdd10-supply = <&reg_dummy>;
+	vdd33-supply = <&reg_dummy>;
+
+	status = "okay";
+};
+
+&usbdrd_dwc3 {
+	dr_mode = "otg";
+	maximum-speed = "high-speed";
+};
+
+&usbdrd_phy {
+	status = "okay";
+};
+
+&watchdog_cl0 {
+	status = "okay";
+};
+
+&watchdog_cl1 {
+	status = "okay";
+};
diff --git a/arch/arm64/boot/dts/exynos/exynos850.dtsi b/arch/arm64/boot/dts/exynos/exynos850.dtsi
index 7fae8888952a..c8e4c234223c 100644
--- a/arch/arm64/boot/dts/exynos/exynos850.dtsi
+++ b/arch/arm64/boot/dts/exynos/exynos850.dtsi
@@ -160,7 +160,7 @@ psci {
 		method = "smc";
 	};
 
-	timer {
+	timer: timer {
 		compatible = "arm,armv8-timer";
 		/* Hypervisor Virtual Timer interrupt is not wired to GIC */
 		interrupts =
-- 
2.47.3

Re: [PATCH v3 2/2] arm64: dts: exynos: Add initial support for Samsung Galaxy A21s (SM-A217F)

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] dts: unintended override of mmc_0 compatible string
- [Low] dts: build failure due to undefined gpu label
--

commit 5ffd2971505c8c2076142840ef189e608c1e56c2
Author: Thomas Turner <tturner@lineageos.org>
arm64: dts: exynos: Add initial support for Samsung Galaxy A21s (SM-A217F)

This commit adds initial device tree support for the Samsung Galaxy A21s (SM-A217F) phone, based on the Exynos 850 SoC. It defaults to the 3GB RAM configuration and includes support for simple-framebuffer, buttons, MMC, USB, and watchdog.

> diff --git a/arch/arm64/boot/dts/exynos/exynos850-a217f.dts b/arch/arm64/boot/dts/exynos/exynos850-a217f.dts
> new file mode 100644
> --- /dev/null
> +++ b/arch/arm64/boot/dts/exynos/exynos850-a217f.dts

[ ... ]

> +&gpu {
> +	mali-supply = <&reg_dummy>;
> +
> +	status = "okay";
> +};

[Severity: Low]
Does this cause a build regression during dtc compilation? 

The gpu label is referenced here at the root level, but it appears to be 
undefined in the included exynos850.dtsi file. This would result in a 
syntax error for the missing label when running make dtbs for this board.

> +
> +&mmc_0 {
> +	compatible = "samsung,exynos7-dw-mshc";
> +	mmc-hs200-1_8v;

[Severity: Medium]
Is this generic compatible string intended to override the SoC-specific one?

The exynos850.dtsi core IP block definition properly includes the -smu suffix
for IOMMU integration. Overriding it in the board file with this older generic
string drops the IOMMU matching. This might cause DMA handling issues or
missing functionality for the MMC controller.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260916205522.159393-1-tturner@lineageos.org?part=2

Re: [PATCH v3 0/2] Add Samsung Galaxy A21s support

[Krzysztof Kozlowski]

On Wed, 16 Sep 2026 21:55:20 +0100, Thomas Turner wrote:
> This is a small patch series which adds support to the Samsung Galaxy
> A21s. This device is part of the Exynos850 SoC and its device tree is
> very loosely based on the e850-95 one.
> 
> Thomas Turner (2):
>   dt-bindings: arm: samsung: Add compatible for Samsung Galaxy A21s
>     (SM-A217F)
>   arm64: dts: exynos: Add initial support for Samsung Galaxy A21s
>     (SM-A217F)
> 
> [...]

Applied, thanks!

[1/2] dt-bindings: arm: samsung: Add compatible for Samsung Galaxy A21s (SM-A217F)
      https://git.kernel.org/krzk/linux/c/1a672a79f917c9d5322b42f30efe27e1679c1612
[2/2] arm64: dts: exynos: Add initial support for Samsung Galaxy A21s (SM-A217F)
      https://git.kernel.org/krzk/linux/c/3836879a69ffe2b06ddbbb1cd0a98928a1ef6dd1

Best regards,
-- 
Krzysztof Kozlowski <krzk@kernel.org>