查看“Linux内核-网卡驱动移植”的源代码

==实验原理==
STM32MP157A系列SoC集成一个千兆以太网媒体访问控制器，支持RMII和MII两种标准的PHY，FS-MP1A设备上外接了一个瑞昱的千兆以太网PHY芯片RTL8211F，原理图如下： <br>

[[Image:50-1-1-1.png|640px]] <br>

查看原理图得出RTL8211F数据管脚与STM32MP157A的管脚对应关系如下：

{|class="wikitable"
|-
! 原理图网络编号 !! 对应管脚 !! 管脚功能 !! 管脚功能码
|-
| ETH_MDC 
| PC1 
| ETH1_MDC
| AF11 
|-
| ETH_MDIO 
| PA2 
| ETH1_MDIO
| AF11 
|-
| ETH_TXD0 
| PG13 
| ETH1_*MII_ TXD0
| AF11 
|-
| ETH_TXD1 
| PG14 
| ETH1_*MII_ TXD1
| AF11 
|-
| ETH_TXD2 
| PC2 
| ETH1_*MII_ TXD2
| AF11 
|-
| ETH_TXD3 
| PE2 
| ETH1_*MII_ TXD3
| AF11 
|-
| ETH_TX_EN 
| PB11 
| ETH1_*MII_ TX_EN
| AF11 
|-
| ETH_TX_CLK
| PG4 
| ETH1_*MII_ GTX_CLK
| AF11 
|-
| ETH_RXD0 
| PC4 
| ETH1_*MII_ RXD0
| AF11 
|-
| ETH_RXD1 
| PC5 
| ETH1_*MII_ RXD1
| AF11 
|-
| ETH_RXD2 
| PB0 
| ETH1_*MII_ RXD2
| AF11 
|-
| ETH_RXD3 
| PB1 
| ETH1_*MII_ RXD3
| AF11 
|-
| ETH_RX_DV 
| PA7 
| ETH1_*MII_RX _DV
| AF11 
|-
| ETH_RX_CLK 
| PA1 
| ETH1_*MII_RX _CLK
| AF11 
|-
| ETH_CLK125 
| PG5 
| ETH1_*MII_ CLK125
| AF11 
|-
| ETH_RST 
| PH2 
| ETH1_*MII_ CRS
| AF11 
|}
<ol>
<li>网卡设备树节点</li><br>

参考文档：
<pre><nowiki>
Documentation/devicetree/bindings/net/stm32-dwmac.txt
Documentation/devicetree/bindings/net/ethernet-controller.yaml
Documentation/devicetree/bindings/net/ethernet-phy.yaml
Documentation/devicetree/bindings/net/snps,dwmac.yam
</nowiki></pre>
内核中ST对STM32MP15x系列芯片的设备树资源了做了定义，可参见：
 arch/arm/boot/dts/stm32mp151.dtsi
stm32mp151中ethernet定义如下：
<pre><nowiki>
ethernet0: ethernet@5800a000 {
	compatible = "st,stm32mp1-dwmac", "snps,dwmac-4.20a";
	reg = <0x5800a000 0x2000>;
	reg-names = "stmmaceth";
	interrupts-extended = <&intc GIC_SPI 61 IRQ_TYPE_LEVEL_HIGH>,
					      <&exti 70 IRQ_TYPE_LEVEL_HIGH>;
	interrupt-names = "macirq",
					  "eth_wake_irq";
	clock-names = "stmmaceth",
				   "mac-clk-tx",
				   "mac-clk-rx",
				   "ethstp";
	clocks = <&rcc ETHMAC>,
			 <&rcc ETHTX>,
			 <&rcc ETHRX>,
			 <&rcc ETHSTP>;
	st,syscon = <&syscfg 0x4>;
	snps,mixed-burst;
	snps,pbl = <2>;
	snps,en-tx-lpi-clockgating;
	snps,axi-config = <&stmmac_axi_config_0>;
	snps,tso;
	power-domains = <&pd_core>;
	status = "disabled";
};
</nowiki></pre>
上述代码只对ethernet做了基本的初始化，并没有针对不同的硬件设计做适配，所以需结合硬件补全设备树节点信息。<br>

对照内核文档目录下相关文档添加补充相关信息，亦可参考内核中其他设备树文件中相关描述，比如stm32mp15xx-dkx.dtsi关于ethernet的描述符合我们的要求，内容如下：
<pre><nowiki>
&ethernet0 {
	status = "okay";
	pinctrl-0 = <&ethernet0_rgmii_pins_a>;
	pinctrl-1 = <&ethernet0_rgmii_pins_sleep_a>;
	pinctrl-names = "default", "sleep";
	phy-mode = "rgmii-id";
	max-speed = <1000>;
	phy-handle = <&phy0>;

	mdio0 {
		#address-cells = <1>;
		#size-cells = <0>;
		compatible = "snps,dwmac-mdio";
		phy0: ethernet-phy@0 {
			reg = <0>;
		};
	};
};
</nowiki></pre>
<li>管脚定义</li><br>

在内核中STM32MP1默认管脚定义在文件arch/arm/dts/stm32mp15-pinctrl.dtsi中，查看文件中是否有需要的管脚定义：<br>

查看后确认有ethernet的管脚定义，且与FS-MP1A硬件使用情况一致，定义如下：
<pre><nowiki>
ethernet0_rgmii_pins_a: rgmii-0 {
	pins1 {
		pinmux = <STM32_PINMUX('G', 5, AF11)>, /* ETH_RGMII_CLK125 */
				 <STM32_PINMUX('G', 4, AF11)>, /* ETH_RGMII_GTX_CLK */
				 <STM32_PINMUX('G', 13, AF11)>, /* ETH_RGMII_TXD0 */
				 <STM32_PINMUX('G', 14, AF11)>, /* ETH_RGMII_TXD1 */
				 <STM32_PINMUX('C', 2, AF11)>, /* ETH_RGMII_TXD2 */
				 <STM32_PINMUX('E', 2, AF11)>, /* ETH_RGMII_TXD3 */
				 <STM32_PINMUX('B', 11, AF11)>, /* ETH_RGMII_TX_CTL */
				 <STM32_PINMUX('C', 1, AF11)>; /* ETH_MDC */
		bias-disable;
		drive-push-pull;
		slew-rate = <2>;
	};
	pins2 {
		pinmux = <STM32_PINMUX('A', 2, AF11)>; /* ETH_MDIO */
		bias-disable;
		drive-push-pull;
		slew-rate = <0>;
	};
	pins3 {
		pinmux = <STM32_PINMUX('C', 4, AF11)>, /* ETH_RGMII_RXD0 */
				 <STM32_PINMUX('C', 5, AF11)>, /* ETH_RGMII_RXD1 */
				 <STM32_PINMUX('B', 0, AF11)>, /* ETH_RGMII_RXD2 */
				 <STM32_PINMUX('B', 1, AF11)>, /* ETH_RGMII_RXD3 */
				 <STM32_PINMUX('A', 1, AF11)>, /* ETH_RGMII_RX_CLK */
				 <STM32_PINMUX('A', 7, AF11)>; /* ETH_RGMII_RX_CTL */
		bias-disable;
	};
};

ethernet0_rgmii_pins_sleep_a: rgmii-sleep-0 {
	pins1 {
		pinmux = <STM32_PINMUX('G', 5, ANALOG)>, /* ETH_RGMII_CLK125 */
				 <STM32_PINMUX('G', 4, ANALOG)>, /* ETH_RGMII_GTX_CLK */
				 <STM32_PINMUX('G', 13, ANALOG)>, /* ETH_RGMII_TXD0 */
				 <STM32_PINMUX('G', 14, ANALOG)>, /* ETH_RGMII_TXD1 */
				 <STM32_PINMUX('C', 2, ANALOG)>, /* ETH_RGMII_TXD2 */
				 <STM32_PINMUX('E', 2, ANALOG)>, /* ETH_RGMII_TXD3 */
				 <STM32_PINMUX('B', 11, ANALOG)>, /* ETH_RGMII_TX_CTL */
				 <STM32_PINMUX('A', 2, ANALOG)>, /* ETH_MDIO */
				 <STM32_PINMUX('C', 1, ANALOG)>, /* ETH_MDC */
				 <STM32_PINMUX('C', 4, ANALOG)>, /* ETH_RGMII_RXD0 */
				 <STM32_PINMUX('C', 5, ANALOG)>, /* ETH_RGMII_RXD1 */
				 <STM32_PINMUX('B', 0, ANALOG)>, /* ETH_RGMII_RXD2 */
				 <STM32_PINMUX('B', 1, ANALOG)>, /* ETH_RGMII_RXD3 */
				 <STM32_PINMUX('A', 1, ANALOG)>, /* ETH_RGMII_RX_CLK */
				 <STM32_PINMUX('A', 7, ANALOG)>; /* ETH_RGMII_RX_CTL */
	};
};
</nowiki></pre>
</ol>

==实验目的==
熟悉基于Linux操作系统下的网卡驱动移植配置过程。

==实验平台==
华清远见开发环境，FS-MP1A平台；

==实验步骤==
*添加网卡设备树配置。<br>

修改arch/arm/dts/stm32mp15xx-fsmp1x.dts文件<br>

在文件末尾添加如下内容：
<pre><nowiki>
&ethernet0 {
	status = "okay";
	pinctrl-0 = <&ethernet0_rgmii_pins_a>;
	pinctrl-1 = <&ethernet0_rgmii_pins_sleep_a>;
	pinctrl-names = "default", "sleep";
	phy-mode = "rgmii-id";
	max-speed = <1000>;
	phy-handle = <&phy0>;

	mdio0 {
		#address-cells = <1>;
		#size-cells = <0>;
		compatible = "snps,dwmac-mdio";
		phy0: ethernet-phy@0 {
			reg = <0>;
		};
	};
};
</nowiki></pre>
*配置内核<br>

由于内核源码默认配置以及支持网卡，本节列出主要选项，如下：
<pre><nowiki>
linux@ubuntu:$ make menuconfig
Device Drivers  --->
	[*] Network device support  --->
			[*]   Ethernet driver support  --->
			<*>     STMicroelectronics Multi-Gigabit Ethernet driver
			<*>       STMMAC Platform bus support
			<*>         Support for snps,dwc-qos-ethernet.txt DT binding.
			<*>         Generic driver for DWMAC
			<*>         STM32 DWMAC support
</nowiki></pre>
*编译内核及设备树：
 linux@ubuntu:$ make -j4 uImage dtbs LOADADDR=0xC2000040
*重启测试<br>

将编译好的设备树和内核镜像拷贝到/tftpboot目录下，通过tftp引导内核，重启设备后可以看到如下启动信息：

[[Image:50-1-4-1.png]] <br>

[[Image:50-1-4-2.png]] <br>

通过Ping 测试网卡
 linux@fsmp1a:$ ping www.baidu.com

[[Image:50-1-4-3.png]] <br>

如果设备不能接入以太网，可以ping主机