/* include/linux/device.h */
 
struct bus_type {
    const char *name;                                  /* 總線名字 */
    const char *dev_name; 
    struct device *dev_root;
    struct device_attribute *dev_attrs;
    const struct attribute_group **bus_groups;         /* 總線屬性 */
    const struct attribute_group **dev_groups;         /* 設(shè)備屬性 */
    const struct attribute_group **drv_groups;         /* 驅(qū)動屬性 */
 
    int (*match)(struct device *dev, struct device_driver *drv);      /* 設(shè)備驅(qū)動匹配函數(shù) */
    int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
    int (*probe)(struct device *dev);
    int (*remove)(struct device *dev);
    void (*shutdown)(struct device *dev);
 
    int (*online)(struct device *dev);
    int (*offline)(struct device *dev);
    int (*suspend)(struct device *dev, pm_message_t state);
    int (*resume)(struct device *dev);
    const struct dev_pm_ops *pm;
    const struct iommu_ops *iommu_ops;
    struct subsys_private *p;
    struct lock_class_key lock_key;
};

/* drivers/base/platform.c */
 
struct bus_type platform_bus_type = {
    .name = "platform",
    .dev_groups = platform_dev_groups,
    .match = platform_match,       /* 匹配函數(shù) */
    .uevent = platform_uevent,
    .pm = &platform_dev_pm_ops,
};

/* drivers/base/platform.c */
 
static int platform_match(struct device *dev, struct device_driver *drv)
{
    struct platform_device *pdev = to_platform_device(dev);
    struct platform_driver *pdrv = to_platform_driver(drv);
 
    /*When driver_override is set,only bind to the matching driver*/
    if (pdev->driver_override)
        return !strcmp(pdev->driver_override, drv->name);
 
    /* 設(shè)備樹OF類型匹配
       驅(qū)動基類的 of_match_table 里的 compatible 匹配表與設(shè)備樹
       每一個設(shè)備節(jié)點(diǎn)的 compatible 屬性作比較，有相同就表示匹配成功 */
    if (of_driver_match_device(dev, drv))
        return 1;
 
    /* ACPI 匹配 */
    if (acpi_driver_match_device(dev, drv))
        return 1;
 
    /* id_table 匹配
       platform 驅(qū)動里的 id_table 數(shù)組會保存很多 id 信息  */
    if (pdrv->id_table)
        return platform_match_id(pdrv->id_table, pdev) != NULL;
 
    /* name 匹配
       直接粗暴比較platform 的驅(qū)動和設(shè)備里面的 name 信息 */
    return (strcmp(pdev->name, drv->name) == 0);
}

/* include/linux/platform_device.h */
 
struct platform_driver {
    int (*probe)(struct platform_device *);    /* platform驅(qū)動和platform設(shè)備匹配后會執(zhí)行這個probe函數(shù) */
    int (*remove)(struct platform_device *);
    void (*shutdown)(struct platform_device *);
    int (*suspend)(struct platform_device *, pm_message_t state);
    int (*resume)(struct platform_device *);
    struct device_driver driver;                /* 驅(qū)動基類 */
    const struct platform_device_id *id_table;  /* id_table表 */
    bool prevent_deferred_probe;
};

struct platform_device_id {
    char name[PLATFORM_NAME_SIZE];
    kernel_ulong_t driver_data;
};

/* include/linux/device.h */
 
struct device_driver {
    const char *name;                               /* platform 總線來匹配設(shè)備與驅(qū)動的第四種方        
                                                       法就是直接粗暴匹配兩者的 name 字段 */
    struct bus_type *bus;
    struct module *owner;
    const char *mod_name; 
    bool suppress_bind_attrs; 
    const struct of_device_id *of_match_table;      /* 采用設(shè)備樹時驅(qū)動使用的的匹配表 */
    const struct acpi_device_id *acpi_match_table;
    int (*probe) (struct device *dev);
    int (*remove) (struct device *dev);
    void (*shutdown) (struct device *dev);
    int (*suspend) (struct device *dev, pm_message_t state);
    int (*resume) (struct device *dev);
    const struct attribute_group **groups;
    const struct dev_pm_ops *pm;
    struct driver_private *p;
};

/* include/linux/mod_devicetable.h */
 
struct of_device_id {
    char name[32];
    char type[32];
    char compatible[128];   /* 使用設(shè)備樹匹配時就是把設(shè)備節(jié)點(diǎn)的 compatible 屬性值和 of_match_table 中
                               每個項目的這個 compatible 作比較，如果有相等的就表示設(shè)備和驅(qū)動匹配成功 */
    const void *data;
};

platform_driver_register (drv)
    -> __platform_driver_register
        -> drv->driver.probe = platform_drv_probe;       /* 把 platform_drv_probe 這個函數(shù)賦給
                                                            platform 驅(qū)動里的驅(qū)動基類 drier 的 probe 函數(shù) */
        -> driver_registe (&drv->driver)                 /* 向 Linux 內(nèi)核注冊驅(qū)動基類 driver  */
            -> ...... 
                -> drv->driver->probe                    /* 最終執(zhí)行驅(qū)動基類 driver 的 probe 函數(shù)，
                                                            其實(shí)就是上面給的 platform_drv_probe 函數(shù) */
                    -> platform_drv_probe
                        -> drv->probe                    /* platform_drv_probe 函數(shù)又會執(zhí)行                 
                                                            platform 驅(qū)動 drv 的 probe 函數(shù) */

driver_register(&drv->driver)
    -> bus_add_driver                             /* 向總線添加驅(qū)動 */
        -> driver_attach 
            -> bus_for_each_dev                   /* 查找總線下每一個設(shè)備，即遍歷操作 */ 
                -> __driver_attach                /* 每個設(shè)備都調(diào)用此函數(shù) */
                    -> driver_match_device        /* 檢查是否匹配 */
                        -> 調(diào)用bus下的match匹配函數(shù)
                    -> driver_probe_device        /* 匹配成功后執(zhí)行此函數(shù) */
                        -> really_probe 
                            -> drv->probe         /* 執(zhí)行drv下的probe函數(shù) */

/* include/linux/platform_device.h */
 
struct platform_device {
    const char *name;                   /* 設(shè)備名，得和對應(yīng)的 platform 驅(qū)動的 name 一樣，
                                           否則設(shè)備就無法匹配到對應(yīng)驅(qū)動 */
    int id; 
    bool id_auto;
    struct device dev;
    u32 num_resources; 
    struct resource *resource;
    const struct platform_device_id *id_entry;
    char *driver_override; /* Driver name to force a match */
    /* MFD cell pointer */
    struct mfd_cell *mfd_cell;
    /* arch specific additions */
    struct pdev_archdata archdata;
};

platform_match
    -> of_driver_match_device          /* 設(shè)備樹匹配 */
    -> acpi_driver_match_device        /* ACPI 匹配 */
    -> platform_match_id               /* platform_driver->id_table 匹配 */
    -> strcmp(pdev->name, drv->name)   /* name 匹配 */

of_driver_match_device     /* of函數(shù)一般是用于設(shè)備樹，這也算給了我們提示 */
    -> of_match_device (drv->of_match_table, dev)    
        -> of_match_node  
            -> __of_match_node
                -> __of_device_is_compatible
                    -> __of_find_property(device, "compatible", NULL)   /* 取出compatible屬性值 */