const struct of_device_id  of_default_bus_match_table[] = {

    {  .compatible = "simple-bus", },

    {  .compatible = "simple-mfd", },

#ifdef CONFIG_ARM_AMBA

    {  .compatible = "arm,amba-bus", },

#endif /* CONFIG_ARM_AMBA */

    {}  /* Empty terminated list */

};

int of_platform_populate(struct  device_node *root,

           const  struct of_device_id *matches,

           const  struct of_dev_auxdata *lookup,

           struct  device *parent)

{

    struct  device_node *child;

    int  rc = 0;

    /*  

    root  = root ? of_node_get(root) : of_find_node_by_path("/");

    if  (!root)

       return  -EINVAL;

    /*  為根節點下面的每一個節點建立platform_device結構體 */

    for_each_child_of_node(root,  child) {

       rc  = of_platform_bus_create(child, matches, lookup, parent, true);

       if  (rc) {

           of_node_put(child);

           break;

       }

    }

    /*  更新device_node flag標誌位 */

    of_node_set_flag(root,  OF_POPULATED_BUS);

    of_node_put(root);

    return  rc;

}

static int of_platform_bus_create(struct  device_node *bus,

                const struct of_device_id *matches,

                const struct of_dev_auxdata *lookup,

                struct device *parent, bool strict)

{

    const  struct of_dev_auxdata *auxdata;

    struct  device_node *child;

    struct  platform_device *dev;

    const  char *bus_id = NULL;

    void  *platform_data = NULL;

    int  rc = 0;

    /*  只有包含"compatible"屬性的node節點才會生成相應的platform_device結構體 */

    /*  Make sure it has a compatible property */

    if  (strict && (!of_get_property(bus, "compatible", NULL))) {

       return  0;

    }

    /*  省略部分程式碼 */

    /*  

     *針對節點下面得到status = "ok"或者status = "okay"或者不存在status屬性的

     *節點分配記憶體並填充platform_device結構體

     */

    dev  = of_platform_device_create_pdata(bus, bus_id, platform_data, parent);

    if  (!dev || !of_match_node(matches, bus))

       return  0;

    /*  遞迴呼叫節點解析函式，為子節點繼續生成platform_device結構體，前提是父節點

     *的“compatible” = “simple-bus”，也就是匹配of_default_bus_match_table結構體中的資料

     */

    for_each_child_of_node(bus,  child) {

       rc  = of_platform_bus_create(child, matches, lookup, &dev->dev, strict);

       if  (rc) {

           of_node_put(child);

           break;

       }

    }

    of_node_set_flag(bus,  OF_POPULATED_BUS);

    return  rc;

}