phy device 和 driver

phy的驱动分为platform_driver_register和platform_device_register 两部分。这两部分都是挂在mdio总线上。这里以hns驱动为例。说先定义mido对应的struct mii_bus *new_bus;static int hns_mdio_probe(struct platform_device *pdev){    struct hns_mdio_device *mdio_dev;    struct mii_bus *new_bus;    struct resource *res;    int ret = -ENODEV;    if (!pdev) {        dev_err(NULL, "pdev is NULL!\r\n");        return -ENODEV;    }    mdio_dev = devm_kzalloc(&pdev->dev, sizeof(*mdio_dev), GFP_KERNEL);    if (!mdio_dev)        return -ENOMEM;    new_bus = devm_mdiobus_alloc(&pdev->dev);    if (!new_bus) {        dev_err(&pdev->dev, "mdiobus_alloc fail!\n");        return -ENOMEM;    }    new_bus->name = MDIO_BUS_NAME;    new_bus->read = hns_mdio_read;    new_bus->write = hns_mdio_write;    new_bus->reset = hns_mdio_reset;    new_bus->priv = mdio_dev;    new_bus->parent = &pdev->dev;    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);    mdio_dev->vbase = devm_ioremap_resource(&pdev->dev, res);    if (IS_ERR(mdio_dev->vbase)) {        ret = PTR_ERR(mdio_dev->vbase);        return ret;    }    platform_set_drvdata(pdev, new_bus);    snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s-%s", "Mii",         dev_name(&pdev->dev));    if (dev_of_node(&pdev->dev)) {        struct of_phandle_args reg_args;        ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node,                               "subctrl-vbase",                               4,                               0,                               &reg_args);        if (!ret) {            mdio_dev->subctrl_vbase =                syscon_node_to_regmap(reg_args.np);            if (IS_ERR(mdio_dev->subctrl_vbase)) {                dev_warn(&pdev->dev, "syscon_node_to_regmap error\n");                mdio_dev->subctrl_vbase = NULL;            } else {                if (reg_args.args_count == 4) {                    mdio_dev->sc_reg.mdio_clk_en =                        (u16)reg_args.args[0];                    mdio_dev->sc_reg.mdio_clk_dis =                        (u16)reg_args.args[0] + 4;                    mdio_dev->sc_reg.mdio_reset_req =                        (u16)reg_args.args[1];                    mdio_dev->sc_reg.mdio_reset_dreq =                        (u16)reg_args.args[1] + 4;                    mdio_dev->sc_reg.mdio_clk_st =                        (u16)reg_args.args[2];                    mdio_dev->sc_reg.mdio_reset_st =                        (u16)reg_args.args[3];                } else {                    /* for compatible */                    mdio_dev->sc_reg.mdio_clk_en =                        MDIO_SC_CLK_EN;                    mdio_dev->sc_reg.mdio_clk_dis =                        MDIO_SC_CLK_DIS;                    mdio_dev->sc_reg.mdio_reset_req =                        MDIO_SC_RESET_REQ;                    mdio_dev->sc_reg.mdio_reset_dreq =                        MDIO_SC_RESET_DREQ;                    mdio_dev->sc_reg.mdio_clk_st =                        MDIO_SC_CLK_ST;                    mdio_dev->sc_reg.mdio_reset_st =                        MDIO_SC_RESET_ST;                }            }        } else {            dev_warn(&pdev->dev, "find syscon ret = %#x\n", ret);            mdio_dev->subctrl_vbase = NULL;        }        ret = of_mdiobus_register(new_bus, pdev->dev.of_node);    } else if (is_acpi_node(pdev->dev.fwnode)) {        /* Clear all the IRQ properties */        memset(new_bus->irq, PHY_POLL, 4 * PHY_MAX_ADDR);        /* Mask out all PHYs from auto probing. */        new_bus->phy_mask = ~0;        /* Register the MDIO bus */核心是调用mdiobus_register，然后scan这个bus上对应的device        ret = mdiobus_register(new_bus);    } else {        dev_err(&pdev->dev, "Can not get cfg data from DT or ACPI\n");        ret = -ENXIO;    }    if (ret) {        dev_err(&pdev->dev, "Cannot register as MDIO bus!\n");        platform_set_drvdata(pdev, NULL);        return ret;    }    return 0;}mdiobus_register->__mdiobus_register    for (i = 0; i < PHY_MAX_ADDR; i++) {        if ((bus->phy_mask & (1 << i)) == 0) {            struct phy_device *phydev;            phydev = mdiobus_scan(bus, i);            if (IS_ERR(phydev) && (PTR_ERR(phydev) != -ENODEV)) {                err = PTR_ERR(phydev);                goto error;            }        }    }根据phy id去通过上面注册的mdio的read函数实际去读芯片的寄存器，看这个phy id 对应的device是否存在struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr){    struct phy_device *phydev;    int err;    phydev = get_phy_device(bus, addr, false);    if (IS_ERR(phydev))        return phydev;    /*     * For DT, see if the auto-probed phy has a correspoding child     * in the bus node, and set the of_node pointer in this case.     */    of_mdiobus_link_mdiodev(bus, &phydev->mdio);    err = phy_device_register(phydev);    if (err) {        phy_device_free(phydev);        return ERR_PTR(-ENODEV);    }    return phydev;}如果get_phy_device 返回成功的话，说明这个phy id对应的硬件是存在的，就调用phy_device_register 创建phy devicestatic int get_phy_id(struct mii_bus *bus, int addr, u32 *phy_id,              bool is_c45, struct phy_c45_device_ids *c45_ids){    int phy_reg;    if (is_c45)        return get_phy_c45_ids(bus, addr, phy_id, c45_ids);    /* Grab the bits from PHYIR1, and put them in the upper half */    phy_reg = mdiobus_read(bus, addr, MII_PHYSID1);    if (phy_reg < 0)        return -EIO;    *phy_id = (phy_reg & 0xffff) << 16;    /* Grab the bits from PHYIR2, and put them in the lower half */    phy_reg = mdiobus_read(bus, addr, MII_PHYSID2);    if (phy_reg < 0)        return -EIO;    *phy_id |= (phy_reg & 0xffff);    return 0;}可见最终通过mdiobus_read 去读寄存器int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum){    int retval;    BUG_ON(in_interrupt());    mutex_lock(&bus->mdio_lock);    retval = bus->read(bus, addr, regnum);    mutex_unlock(&bus->mdio_lock);    trace_mdio_access(bus, 1, addr, regnum, retval, retval);    return retval;}最终调用mido bus的read函数去读的。到这里已经准备好phy device。下来就要调用module_phy_driver(marvell_drivers); 来注册phy driver那phy的device和driver是如何配对的呢？get_phy_device->phy_device_createstruct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id,                     bool is_c45,                     struct phy_c45_device_ids *c45_ids){    struct phy_device *dev;    struct mdio_device *mdiodev;    /* We allocate the device, and initialize the default values */    dev = kzalloc(sizeof(*dev), GFP_KERNEL);    if (!dev)        return ERR_PTR(-ENOMEM);    mdiodev = &dev->mdio;    mdiodev->dev.release = phy_device_release;    mdiodev->dev.parent = &bus->dev;    mdiodev->dev.bus = &mdio_bus_type;    mdiodev->bus = bus;    mdiodev->pm_ops = MDIO_BUS_PHY_PM_OPS;    mdiodev->bus_match = phy_bus_match;}可以看到bus_match 函数是phy_bus_matchstatic int phy_bus_match(struct device *dev, struct device_driver *drv){    struct phy_device *phydev = to_phy_device(dev);    struct phy_driver *phydrv = to_phy_driver(drv);    const int num_ids = ARRAY_SIZE(phydev->c45_ids.device_ids);    int i;    if (!(phydrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY))        return 0;    if (phydrv->match_phy_device)        return phydrv->match_phy_device(phydev);    if (phydev->is_c45) {        for (i = 1; i < num_ids; i++) {            if (!(phydev->c45_ids.devices_in_package & (1 << i)))                continue;            if ((phydrv->phy_id & phydrv->phy_id_mask) ==                (phydev->c45_ids.device_ids[i] &                 phydrv->phy_id_mask))                return 1;        }        return 0;    } else {        return (phydrv->phy_id & phydrv->phy_id_mask) ==            (phydev->phy_id & phydrv->phy_id_mask);    }}从phy_bus_match 中可以知道是根据phy id 来配对的.