Ambarella Ethernet PHY rtl9000 Linux driver 調試

記錄在ambarella CV22平台 調試rtl9000 phy驅動。

rtl9000 工作原理

如圖，PHY使用标準的mac和phy的接口，rtl9000支援rgmii/rmii/mii和mdio/mdc接口，還有reset和外部供電，外部晶振接口。

另外硬體上還需要配置rtl9000的addr和硬體接口。

ambarella dts配置

mac0: [email protected] {
			amb,tx-clk-invert;
			pinctrl-0 = <&rmii_pins &ahb_mdio_pins>;
			amb,ahb-12mhz-div = <5>;
			phy-mode = "rmii";
			amb,ext-ref-clk;
			[email protected] {
				reg = <0>;
				rst-gpios = <&gpio 29 0>;
			};

		};
           

驅動修改

ambarella\kernel\linux-4.14\drivers\net\phy\realtek.c

static struct phy_driver realtek_drvs[] = {
	{
		.phy_id		= 0x001ccb00,
		.name		= "RTL9000 Gigabit Ethernet",
		.phy_id_mask	= 0x001fffff,
		.features       = PHY_BASIC_FEATURES,
		.flags		= PHY_HAS_INTERRUPT,
		.probe = rtl9000_probe,
		.config_aneg	= &rtl9000_config_aneg,
		.aneg_done	= &rtl9000_aneg_done,
		.config_init	= &rtl9000_config_init,
		.read_status	= &rtl9000_read_status,
		.ack_interrupt	= &rtl9000_ack_interrupt,
		.config_intr	= &rtl9000_config_intr,
		.suspend	= genphy_suspend,
		.resume		= genphy_resume,
	},
};

module_phy_driver(realtek_drvs);

static struct mdio_device_id __maybe_unused realtek_tbl[] = {
	{ 0x001ccb00, 0x001fffff },
	{ }
};
           

最重要需要實作的幾個個函數：

.config_aneg	= &rtl9000_config_aneg,
.aneg_done	= &rtl9000_aneg_done,
.config_init	= &rtl9000_config_init,
.read_status	= &rtl9000_read_status,
           

在phy的驅動架構中要求我們必須實作config_aneg和read_status這兩個函數。

ping不通問題

在調試過程中，發現PHY的id已經讀到了，網卡裝置也建立成功，mac位址也有。但是ping不通主機。

解決：通過ethtool eth0檢視網絡狀态，發現不正确，修改read_status函數如下，可以正常ping通。

static int rtl9000_read_status(struct phy_device *phydev)
{
	
	phydev->duplex = DUPLEX_FULL;
	phydev->speed = SPEED_100;
	phydev->pause = 0;
	phydev->asym_pause = 0;

	phydev->link = 1;
	return 0;
	
}