[patch 3/5] DT nodes for AST2500 DMA UART driver

sudheer.v open.sudheer at gmail.com
Fri Jun 21 21:17:33 AEST 2019


From: sudheer veliseti <sudheer.open at gmail.com>

DT node for DMA controller(ast_uart_sdma) doesn't bind to any DMA controller driver.
This is because Software for DMA controller is not based on DMA framework,but is dedicated
and serves only UARTs in AST2500. ast_uart_sdma node is searched by compatible string in the 
driver software.basic use of this node is to provide register base address of DMA controller and DMA irq number(<50>).
IRQ of DMA controller is of crucial importance, which does RX and TX of UART data. 

uart nodes dma_uart1,2...etc binds to the platform driver.
irq numbers <9>,<32>,<33>,<34> in dma_uart nodes install ISRs which are of not much interest in uart data TX/RX .


Signed-off-by: sudheer veliseti <sudheer.open at gmail.com>
---
 arch/arm/boot/dts/aspeed-ast2500-evb.dts | 21 +++++++
 arch/arm/boot/dts/aspeed-g5.dtsi         | 71 ++++++++++++++++++++++--
 2 files changed, 88 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/aspeed-ast2500-evb.dts b/arch/arm/boot/dts/aspeed-ast2500-evb.dts
index 5dbb33c10c4f..4da09fbe94df 100644
--- a/arch/arm/boot/dts/aspeed-ast2500-evb.dts
+++ b/arch/arm/boot/dts/aspeed-ast2500-evb.dts
@@ -64,6 +64,27 @@
 	status = "okay";
 };
 
+&ast_uart_sdma {
+	status = "okay";
+};
+
+&dma_uart1 {
+	status = "okay";
+};
+
+&dma_uart2 {
+	status = "okay";
+};
+
+&dma_uart3 {
+	status = "okay";
+};
+
+&dma_uart4 {
+	status = "okay";
+};
+
+
 &mac0 {
 	status = "okay";
 
diff --git a/arch/arm/boot/dts/aspeed-g5.dtsi b/arch/arm/boot/dts/aspeed-g5.dtsi
index 674746513031..fb7b3ed463de 100644
--- a/arch/arm/boot/dts/aspeed-g5.dtsi
+++ b/arch/arm/boot/dts/aspeed-g5.dtsi
@@ -23,10 +23,10 @@
 		i2c11 = &i2c11;
 		i2c12 = &i2c12;
 		i2c13 = &i2c13;
-		serial0 = &uart1;
-		serial1 = &uart2;
-		serial2 = &uart3;
-		serial3 = &uart4;
+		serial0 = &dma_uart1;
+		serial1 = &dma_uart2;
+		serial2 = &dma_uart3;
+		serial3 = &dma_uart4;
 		serial4 = &uart5;
 		serial5 = &vuart;
 		peci0 = &peci0;
@@ -497,6 +497,69 @@
 				status = "disabled";
 			};
 
+			ast_uart_sdma: uart_sdma at 1e79e000 {
+				compatible = "aspeed,ast-uart-sdma";
+				reg = <0x1e79e000 0x400>;
+				interrupts = <50>;
+				status = "disabled";
+			};
+
+			dma_uart1: dma_uart1 at 1e783000{
+				compatible = "aspeed,ast-sdma-uart";
+				reg = <0x1e783000 0x1000>;
+				reg-shift = <2>;
+				interrupts = <9>;
+				clocks = <&syscon ASPEED_CLK_GATE_UART1CLK>;
+				dma-channel = <0>;
+				no-loopback-test;
+				pinctrl-names = "default";
+				pinctrl-0 = <&pinctrl_txd1_default
+							 &pinctrl_rxd1_default>;
+				status = "disabled";
+			};
+
+			dma_uart2: dma_uart2 at 1e78d000{
+				compatible = "aspeed,ast-sdma-uart";
+				reg = <0x1e78d000 0x1000>;
+				reg-shift = <2>;
+				interrupts = <32>;
+				clocks = <&syscon ASPEED_CLK_GATE_UART2CLK>;
+				dma-channel = <1>;
+				no-loopback-test;
+				pinctrl-names = "default";
+				pinctrl-0 = <&pinctrl_txd2_default
+							 &pinctrl_rxd2_default>;
+				status = "disabled";
+			};
+
+			dma_uart3: dma_uart3 at 1e78e000{
+				compatible = "aspeed,ast-sdma-uart";
+				reg = <0x1e78e000 0x1000>;
+				reg-shift = <2>;
+				interrupts = <33>;
+				clocks = <&syscon ASPEED_CLK_GATE_UART3CLK>;
+				dma-channel = <2>;
+				no-loopback-test;
+				pinctrl-names = "default";
+				pinctrl-0 = <&pinctrl_txd3_default
+							 &pinctrl_rxd3_default>;
+				status = "disabled";
+			};
+
+			dma_uart4: dma_uart4 at 1e78f000{
+				compatible = "aspeed,ast-sdma-uart";
+				reg = <0x1e78f000 0x1000>;
+				reg-shift = <2>;
+				interrupts = <34>;
+				clocks = <&syscon ASPEED_CLK_GATE_UART4CLK>;
+				dma-channel = <3>;
+				no-loopback-test;
+				pinctrl-names = "default";
+				pinctrl-0 = <&pinctrl_txd4_default
+							 &pinctrl_rxd4_default>;
+				status = "disabled";
+			};
+
 			i2c: bus at 1e78a000 {
 				compatible = "simple-bus";
 				#address-cells = <1>;
-- 
2.17.1



More information about the Linux-aspeed mailing list