From d8461fe07c1e4defee981da778eaeec43d4cbba0 Mon Sep 17 00:00:00 2001
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Date: Thu, 9 Jul 2026 11:09:24 +0200
Subject: [PATCH] arm64: dts: mediatek: mt8195: Add and use UART AP_DMA
 controller

This SoC has a DMA controller (AP_DMA) that provides one channel
for each data direction (transmit and receive) for all of the
UART controllers in the SoC.

In order to increase the efficiency of data TX/RX over the UART
controllers, add the UART DMA controller and assign the right
channels to each uart controller.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 arch/arm64/boot/dts/mediatek/mt8195.dtsi | 37 ++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/arch/arm64/boot/dts/mediatek/mt8195.dtsi b/arch/arm64/boot/dts/mediatek/mt8195.dtsi
index c72e34c57629..9aaf8b6edcb5 100644
--- a/arch/arm64/boot/dts/mediatek/mt8195.dtsi
+++ b/arch/arm64/boot/dts/mediatek/mt8195.dtsi
@@ -904,6 +904,31 @@ spmi: spmi@10027000 {
 			assigned-clock-parents = <&topckgen CLK_TOP_ULPOSC1_D10>;
 		};
 
+		apdma: dma-controller@10220880 {
+			compatible = "mediatek,mt8195-uart-dma", "mediatek,mt6835-uart-dma";
+			reg = <0 0x10220880 0 0x80>, <0 0x10220900 0 0x80>,
+			      <0 0x10220980 0 0x80>, <0 0x10220a00 0 0x80>,
+			      <0 0x10220a80 0 0x80>, <0 0x10220b00 0 0x80>,
+			      <0 0x10220b80 0 0x80>, <0 0x10220c00 0 0x80>,
+			      <0 0x10220c80 0 0x80>, <0 0x10220d00 0 0x80>,
+			      <0 0x10220d80 0 0x80>, <0 0x10220e00 0 0x80>;
+			interrupts = <GIC_SPI 174 IRQ_TYPE_LEVEL_HIGH 0>,
+				     <GIC_SPI 175 IRQ_TYPE_LEVEL_HIGH 0>,
+				     <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH 0>,
+				     <GIC_SPI 177 IRQ_TYPE_LEVEL_HIGH 0>,
+				     <GIC_SPI 178 IRQ_TYPE_LEVEL_HIGH 0>,
+				     <GIC_SPI 179 IRQ_TYPE_LEVEL_HIGH 0>,
+				     <GIC_SPI 180 IRQ_TYPE_LEVEL_HIGH 0>,
+				     <GIC_SPI 181 IRQ_TYPE_LEVEL_HIGH 0>,
+				     <GIC_SPI 182 IRQ_TYPE_LEVEL_HIGH 0>,
+				     <GIC_SPI 183 IRQ_TYPE_LEVEL_HIGH 0>,
+				     <GIC_SPI 184 IRQ_TYPE_LEVEL_HIGH 0>,
+				     <GIC_SPI 185 IRQ_TYPE_LEVEL_HIGH 0>;
+			clocks = <&infracfg_ao CLK_INFRA_AO_APDMA_B>;
+			#dma-cells = <1>;
+			dma-requests = <12>;
+		};
+
 		iommu_infra: infra-iommu@10315000 {
 			compatible = "mediatek,mt8195-iommu-infra";
 			reg = <0 0x10315000 0 0x5000>;
@@ -1040,6 +1065,8 @@ uart0: serial@11001100 {
 			interrupts = <GIC_SPI 141 IRQ_TYPE_LEVEL_HIGH 0>;
 			clocks = <&clk26m>, <&infracfg_ao CLK_INFRA_AO_UART0>;
 			clock-names = "baud", "bus";
+			dmas = <&apdma 0>, <&apdma 1>;
+			dma-names = "tx", "rx";
 			status = "disabled";
 		};
 
@@ -1050,6 +1077,8 @@ uart1: serial@11001200 {
 			interrupts = <GIC_SPI 142 IRQ_TYPE_LEVEL_HIGH 0>;
 			clocks = <&clk26m>, <&infracfg_ao CLK_INFRA_AO_UART1>;
 			clock-names = "baud", "bus";
+			dmas = <&apdma 2>, <&apdma 3>;
+			dma-names = "tx", "rx";
 			status = "disabled";
 		};
 
@@ -1060,6 +1089,8 @@ uart2: serial@11001300 {
 			interrupts = <GIC_SPI 143 IRQ_TYPE_LEVEL_HIGH 0>;
 			clocks = <&clk26m>, <&infracfg_ao CLK_INFRA_AO_UART2>;
 			clock-names = "baud", "bus";
+			dmas = <&apdma 4>, <&apdma 5>;
+			dma-names = "tx", "rx";
 			status = "disabled";
 		};
 
@@ -1070,6 +1101,8 @@ uart3: serial@11001400 {
 			interrupts = <GIC_SPI 723 IRQ_TYPE_LEVEL_HIGH 0>;
 			clocks = <&clk26m>, <&infracfg_ao CLK_INFRA_AO_UART3>;
 			clock-names = "baud", "bus";
+			dmas = <&apdma 6>, <&apdma 7>;
+			dma-names = "tx", "rx";
 			status = "disabled";
 		};
 
@@ -1080,6 +1113,8 @@ uart4: serial@11001500 {
 			interrupts = <GIC_SPI 724 IRQ_TYPE_LEVEL_HIGH 0>;
 			clocks = <&clk26m>, <&infracfg_ao CLK_INFRA_AO_UART4>;
 			clock-names = "baud", "bus";
+			dmas = <&apdma 8>, <&apdma 9>;
+			dma-names = "tx", "rx";
 			status = "disabled";
 		};
 
@@ -1090,6 +1125,8 @@ uart5: serial@11001600 {
 			interrupts = <GIC_SPI 725 IRQ_TYPE_LEVEL_HIGH 0>;
 			clocks = <&clk26m>, <&infracfg_ao CLK_INFRA_AO_UART5>;
 			clock-names = "baud", "bus";
+			dmas = <&apdma 10>, <&apdma 11>;
+			dma-names = "tx", "rx";
 			status = "disabled";
 		};