一.结构体
- struct mii_bus {
- const char *name; //总线名
- char id[MII_BUS_ID_SIZE]; //id
- void *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