Linux-3.5-Exynos4412驱动分层分离

linux-3.5/Documentation/driver-model/bus.txt

先写一个简单的例子，是为了给学习platform做准备。

dev.h

 #ifndef  JASON_DEV_H_
 #define JASON_DEV_H_

 #include <linux/device.h>

 struct pridevice {
     struct device device;
     char *name;
 };

 #endif

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/syscalls.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>

 #include "dev.h"

 static int mara_match(struct device *dev, struct device_driver *drv)
 {
     struct pridevice *pdev = container_of(dev, struct pridevice, device);

     printk("match: %s device try match %s driver...\n", pdev->name, drv->name);

     return !strcmp(pdev->name, drv->name );
     //返回值为１代表匹配成功，为０则失败
 }

 static struct bus_type demobus = {
     .name    =    "marathon",
     .match    =    mara_match,
 };
 EXPORT_SYMBOL_GPL(demobus);

 module_driver(demobus, bus_register, bus_unregister);

 MODULE_LICENSE("GPL");

 MODULE_AUTHOR("no name");
 MODULE_VERSION("J-15");
 MODULE_DESCRIPTION("a simple demo for driver module");

bus.c

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/syscalls.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>

 #include "dev.h"

 extern struct bus_type demobus;

 static void demo_release(struct device *dev)
 {
     struct pridevice *pdev = container_of(dev, struct pridevice, device);

     printk("%s device is released....\n", pdev->name);
 }

 static struct pridevice demodev1 = {
     .device = {
         .init_name     = "spring_1",
         .bus           = &demobus,
         .release    = demo_release,
     },
     .name    =  "spring",
 };

 static int demo_init1(void)
 {
     return device_register(&demodev1.device);
 }

 /*此宏用于指定驱动的入口函数，　内核启动或插入模块到内核时被调用*/
 module_init(demo_init1);

 static void demo_exit1(void)
 {
     device_unregister(&demodev1.device);
 }

 /*此宏用于指定驱动模块输出函数*/
 module_exit(demo_exit1);

 MODULE_LICENSE("GPL");

 MODULE_AUTHOR("no name");
 MODULE_VERSION("J-15");
 MODULE_DESCRIPTION("a simple demo for driver module");

dev.c

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/syscalls.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>

 #include "dev.h"

 extern struct bus_type demobus;

 static int demo_probe (struct device *dev)
 {
     /*
          当总线的match函数返回１时，则由内核调用驱动对象的probe指针指向的
         函数
      */

     struct pridevice *pdev = container_of(dev, struct pridevice, device);
     struct device_driver *pdrv = dev->driver;

     printk("probe: %s driver do %s device...\n",
             pdrv->name, pdev->name);

     return ;
 }

 static int demo_remove (struct device *dev)
 {
     struct pridevice *pdev = container_of(dev, struct pridevice, device);
     struct device_driver *pdrv = dev->driver;

     printk("remove: %s driver remove %s device...\n",
             pdrv->name, pdev->name);

     return ;
 }

 static struct device_driver demodrv1 = {
     .name    =       "spring",
     .bus            =     &demobus,
     .probe    =    demo_probe,
     .remove    =    demo_remove,
 };

 module_driver(demodrv1, driver_register, driver_unregister);

 MODULE_LICENSE("GPL");

 MODULE_AUTHOR("no name");
 MODULE_VERSION("J-15");
 MODULE_DESCRIPTION("a simple demo for driver module");

drv.c

查看总线:

insmod bus.ko     查看总线:

生成的：marathon

目前还没有加载dev       drv

加载驱动后：

platform 总线是内核自身已经注册好的一种总线，我们无须再注册，直接根据总线的匹配规则
来管理设备对象和驱动对象。那么设备对象和驱动对象的类型如下：

参考手册：linux-3.5/Documentation/driver-model/platform.txt

匹配规则：

看完理解之后，常用第二种和第三种匹配规则：

第二种匹配规则：