zynq-7000系列基于zynq-zed的MAC->MAC 的实现（fixed-link）

zynq-7000系列基于zynq-zed的MAC->MAC 的实现（fixed-link）

                             作者：卢浩  

                                     时间：2017.2.20

                                    转载请注明出处

                                                                

前言：在项目实际使用中，我们有一些应用可以省去以太网phy芯片的，这里我就拿zynq-zed开发板做评估测试。

在VIVADO工程中去掉以太网的MDIO MDC配置，这样就无法读取PHY状态了，因为mac->mac这种连接就是无phy模式下的通讯。

修改内核drivers/net/ethernet/cadence/macb.c文件
@@ -383,27 +383,37 @@ static int macb_mii_probe(struct
net_device *dev

int phy_irq;
int ret;

-	phydev = phy_find_first(bp->mii_bus);
-	if (!phydev) {
-		netdev_err(dev, "no PHY found\n");
-		return -ENXIO;
-	}
+	if (bp->phy_node) {
+		phydev = of_phy_connect(dev, bp->phy_node,
+					&macb_handle_link_change, 0,
+					bp->phy_interface);
+		if (!phydev)
+			return -ENODEV;
+	} else {
+		phydev = phy_find_first(bp->mii_bus);
+		if (!phydev) {
+			netdev_err(dev, "no PHY found\n");
+			return -ENXIO;
+		}

-	pdata = dev_get_platdata(&bp->pdev->dev);
-	if (pdata && gpio_is_valid(pdata->phy_irq_pin)) {
-		ret = devm_gpio_request(&bp->pdev->dev, pdata->phy_irq_pin, "phy int");
-		if (!ret) {
-			phy_irq = gpio_to_irq(pdata->phy_irq_pin);
-			phydev->irq = (phy_irq < 0) ? PHY_POLL : phy_irq;
+		pdata = dev_get_platdata(&bp->pdev->dev);
+		if (pdata && gpio_is_valid(pdata->phy_irq_pin)) {
+			ret = devm_gpio_request(&bp->pdev->dev,
+						pdata->phy_irq_pin, "phy int");
+			if (!ret) {
+				phy_irq = gpio_to_irq(pdata->phy_irq_pin);
+				phydev->irq = (phy_irq < 0) ?
+					      PHY_POLL : phy_irq;
+			}
}
-	}

-	/* attach the mac to the phy */
-	ret = phy_connect_direct(dev, phydev, &macb_handle_link_change,
-				 bp->phy_interface);
-	if (ret) {
-		netdev_err(dev, "Could not attach to PHY\n");
-		return ret;
+		/* attach the mac to the phy */
+		ret = phy_connect_direct(dev, phydev, &macb_handle_link_change,
+					 bp->phy_interface);
+		if (ret) {
+			netdev_err(dev, "Could not attach to PHY\n");
+			return ret;
+		}
}

/* mask with MAC supported features */
@@ -3461,14 +3471,21 @@ static int macb_probe(struct platform_device *pdev)
macb_get_hwaddr(bp);

/* Power up the PHY if there is a GPIO reset */
-	phy_node =  of_get_next_available_child(np, NULL);
-	if (phy_node) {
+	phy_node = of_parse_phandle(np, "phy-handle", 0);
+	if (!phy_node && of_phy_is_fixed_link(np)) {
+		err = of_phy_register_fixed_link(np);
+		if (err < 0) {
+			dev_err(&pdev->dev, "broken fixed-link specification");
+			goto failed_phy;
+		}
+		phy_node = of_node_get(np);
+		bp->phy_node = phy_node;
+	} else {
int gpio = of_get_named_gpio(phy_node, "reset-gpios", 0);
if (gpio_is_valid(gpio))
bp->reset_gpio = gpio_to_desc(gpio);
gpiod_set_value(bp->reset_gpio, GPIOD_OUT_HIGH);
}
-	of_node_put(phy_node);

err = of_get_phy_mode(np);
if (err < 0) {
@@ -3518,6 +3535,9 @@ static int macb_probe(struct platform_device *pdev)
err_out_free_netdev:
free_netdev(dev);

+failed_phy:
+	of_node_put(phy_node);
+
err_disable_clocks:
clk_disable_unprepare(tx_clk);
clk_disable_unprepare(hclk);
@@ -3547,6 +3567,7 @@ static int macb_remove(struct platform_device *pdev)
clk_disable_unprepare(bp->tx_clk);
clk_disable_unprepare(bp->hclk);
clk_disable_unprepare(bp->pclk);
+		of_node_put(bp->phy_node);
free_netdev(dev);
}

修改内核drivers/net/ethernet/cadence/macb.h文件
@@ -906,6 +906,7 @@ struct macb {

struct mii_bus		*mii_bus;
struct phy_device	*phy_dev;
+	struct device_node	*phy_node;
int 			link;
int 			speed;
int 			duplex;

在内核配置文件中添加如下配置：
CONFIG_ETHERNET
CONFIG_NET_CADENCE
CONFIG_MACB
CONFIG_NETDEVICES
CONFIG_HAS_DMA

在dts文件增加如下修改：
修改前：
 51 &gem0 {

 52         status = "okay";

 53         phy-mode = "rgmii-id";

 54         phy-handle = <ðernet_phy>;

 55 

 56         ethernet_phy: ethernet-phy@0 {

 57                 reg = <0>;

 58         };

 59 };

修改后：
 55 &gem0 {

 56                   status = "okay";

 57                   phy-mode = "rgmii-id";

 58                   fixed-link {

 59                                speed = <1000>;

 60                                full-duplex;

 61                              };

 68   };

重新编译内核和dts文件。
上电启动zynq-zed开发板，对网卡进行测试，此时网卡被强制到1000M FULL模式。PHYADDR是0-31.