一.结构体

struct mii_bus {const char *name;	//总线名char id[MII_BUS_ID_SIZE];	//idvoid *priv;	//私有数据int (*read)(struct mii_bus *bus, int phy_id, int regnum);	//读方法int (*write)(struct mii_bus *bus, int phy_id, int regnum, u16 val);	//写方法int (*reset)(struct mii_bus *bus);	//复位struct mutex mdio_lock;struct device *parent;	//父设备enum {MDIOBUS_ALLOCATED = 1,MDIOBUS_REGISTERED,MDIOBUS_UNREGISTERED,MDIOBUS_RELEASED,} state;	//总线状态struct device dev;	//设备文件struct phy_device *phy_map[PHY_MAX_ADDR];	//PHY设备数组u32 phy_mask;int *irq;	//中断
};

二.初始化过程

在phy_init函数中调用了mdio_bus_init初始化mdio总线

int __init mdio_bus_init(void)
{int ret;ret = class_register(&mdio_bus_class);	//注册设备类if (!ret) {ret = bus_register(&mdio_bus_type);	//注册mdio总线if (ret)class_unregister(&mdio_bus_class);}return ret;
}

设备类"/sys/class/mdio_bus"

static struct class mdio_bus_class = {.name		= "mdio_bus",.dev_release	= mdiobus_release,
};

总线类型"/sys/bus/mdio"

struct bus_type mdio_bus_type = {.name		= "mdio_bus",.match		= mdio_bus_match,	//匹配方法.pm		= MDIO_BUS_PM_OPS,
};
EXPORT_SYMBOL(mdio_bus_type);

三.mdio总线注册
1.调用mdiobus_alloc函数分配内存

struct mii_bus *mdiobus_alloc(void)
{struct mii_bus *bus;bus = kzalloc(sizeof(*bus), GFP_KERNEL);	//分配内存if (bus != NULL)bus->state = MDIOBUS_ALLOCATED;return bus;
}
EXPORT_SYMBOL(mdiobus_alloc);

2.填充mii_bus的结构体成员

mii_bus->name 	= ;
mii_bus->read 	= ;
mii_bus->write	= ;
mii_bus->reset	= ;
mii_bus->parent	= ;
mii_bus->priv 	= ;
mii_bus->id	= ;

3.注册mii_bus

int mdiobus_register(struct mii_bus *bus)
{int i, err;if (NULL == bus || NULL == bus->name || NULL == bus->read ||NULL == bus->write)return -EINVAL;BUG_ON(bus->state != MDIOBUS_ALLOCATED &&bus->state != MDIOBUS_UNREGISTERED);bus->dev.parent = bus->parent;bus->dev.class = &mdio_bus_class;	//总线设备类"/sys/bus/mdio_bus"bus->dev.groups = NULL;dev_set_name(&bus->dev, "%s", bus->id);	//设置总线设备名err = device_register(&bus->dev);	//注册设备文件if (err) {printk(KERN_ERR "mii_bus %s failed to register\n", bus->id);return -EINVAL;}mutex_init(&bus->mdio_lock);if (bus->reset)bus->reset(bus);	//总线复位for (i = 0; i < PHY_MAX_ADDR; i++) {if ((bus->phy_mask & (1 << i)) == 0) {struct phy_device *phydev;phydev = mdiobus_scan(bus, i);	//扫描phy设备if (IS_ERR(phydev)) {err = PTR_ERR(phydev);goto error;}}}bus->state = MDIOBUS_REGISTERED;	//状态设置为已注册pr_info("%s: probed\n", bus->name);return 0;
error:while (--i >= 0) {if (bus->phy_map[i])device_unregister(&bus->phy_map[i]->dev);}device_del(&bus->dev);return err;
}
EXPORT_SYMBOL(mdiobus_register);

调用了mdiobus_scan函数

struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
{struct phy_device *phydev;int err;phydev = get_phy_device(bus, addr);	//获取创建phy设备if (IS_ERR(phydev) || phydev == NULL)return phydev;err = phy_device_register(phydev);	//注册phy设备if (err) {phy_device_free(phydev);return NULL;}return phydev;
}
EXPORT_SYMBOL(mdiobus_scan);

动态地创建了PHY设备

四.mii、mdio、phy、mac关系图