调用of_platform_populate函数创建platform device

转载于 :　　http://www.voidcn.com/blog/bin_linux96/article/p-1210202.html


解析完DTB以后，会调用of_platform_populate函数创建platform device,调用顺序如下：

of_platform_populate

of_platform_bus_create

    of_platform_device_create_pdata

      of_device_alloc

     of_device_add

    staticint 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)

{

         conststruct of_dev_auxdata *auxdata;

         structdevice_node *child;

         structplatform_device *dev;

         constchar *bus_id = NULL;

         void*platform_data = NULL;

         intrc = 0;

 

         /*创建platformdevice结构 */

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

         if(!dev || !of_match_node(matches, bus))/*如果不匹配matchs,则不需要为子节点创建platform_device*/

         return0;

         /*遍历所有子节点,递归条用of_platform_bus_create*/

         for_each_child_of_node(bus,child) {

                   pr_debug("   create child: %s\n",child->full_name);

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

         }

         returnrc;

}  

 

struct platform_device*of_platform_device_create_pdata(

                                               structdevice_node *np,

                                               constchar *bus_id,

                                               void*platform_data,

                                               structdevice *parent)

{

         structplatform_device *dev;

         /*分配platform_device结构 */

         dev= of_device_alloc(np, bus_id, parent);

         if(!dev)

                   returnNULL;

         dev->dev.coherent_dma_mask= DMA_BIT_MASK(32);

         dev->dev.bus= &platform_bus_type;

         dev->dev.platform_data= platform_data;

         /*把pltatform添加到系统中 */

         if(of_device_add(dev) != 0) {

                   platform_device_put(dev);

                   returnNULL;

         }

         returndev;

}