一、ID匹配之框架代码

id匹配（可想象成八字匹配）：一个驱动可以对应多个设备 ------优先级次低

注意事项：

1. device模块中，id的name成员必须与struct platform_device中的name成员内容一致，因此device模块中，struct platform_device中的name成员必须指定

2. driver模块中，struct platform_driver成员driver的name成员必须指定，但与device模块中name可以不相同

/*platform device框架*/
#include <linux/module.h> 
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
​
//定义资源数组
​
static void device_release(struct device *dev)
{printk("platform: device release\n");
}
​
struct platform_device_id test_id = {.name = "test_device",
};
​
struct platform_device test_device = {.name = "test_device",//必须初始化.dev.release = device_release, .id_entry = &test_id,
};
​
static int __init platform_device_init(void)
{platform_device_register(&test_device);return 0;
}
​
static void __exit platform_device_exit(void)
{platform_device_unregister(&test_device);
}
​
module_init(platform_device_init);
module_exit(platform_device_exit);
MODULE_LICENSE("Dual BSD/GPL");

/*platform driver框架*/
#include <linux/module.h> 
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
​
static int driver_probe(struct platform_device *dev)
{printk("platform: match ok!\n");return 0;
}
​
static int driver_remove(struct platform_device *dev)
{printk("platform: driver remove\n");return 0;
}
​
struct platform_device_id testdrv_ids[] = 
{[0] = {.name = "test_device"},[1] = {.name = "abcxyz"},[2] = {}, //means ending
};
​
struct platform_driver test_driver = {.probe = driver_probe,.remove = driver_remove,.driver = {.name = "xxxxx", //必须初始化},.id_table = testdrv_ids,
};
​
static int __init platform_driver_init(void)
{platform_driver_register(&test_driver);return 0;
}
​
static void __exit platform_driver_exit(void)
{platform_driver_unregister(&test_driver);
}
​
module_init(platform_driver_init);
module_exit(platform_driver_exit);
MODULE_LICENSE("Dual BSD/GPL");
​

用到结构体数组，一般不指定大小，初始化时最后加{}表示数组结束

设备中增加资源，驱动中访问资源

二、ID匹配之led驱动

三、设备树匹配

设备树匹配：内核启动时根据设备树自动产生的设备 ------ 优先级最高

注意事项：

1. 无需编写device模块，只需编写driver模块

2. 使用compatible属性进行匹配，注意设备树中compatible属性值不要包含空白字符

3. id_table可不设置，但struct platform_driver成员driver的name成员必须设置

/*platform driver框架*/
#include <linux/module.h> 
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
​
static int driver_probe(struct platform_device *dev)
{printk("platform: match ok!\n");return 0;
}
​
static int driver_remove(struct platform_device *dev)
{printk("platform: driver remove\n");return 0;
}
​
struct platform_device_id testdrv_ids[] = 
{[0] = {.name = "test_device"},[1] = {.name = "abcxyz"},[2] = {}, //means ending
};
​
struct of_device_id test_of_ids[] = 
{[0] = {.compatible = "xyz,abc"},[1] = {.compatible = "qwe,opq"},[2] = {},
};
​
struct platform_driver test_driver = {.probe = driver_probe,.remove = driver_remove,.driver = {.name = "xxxxx", //必须初始化.of_match_table = test_of_ids,},
};
​
static int __init platform_driver_init(void)
{platform_driver_register(&test_driver);return 0;
}
​
static void __exit platform_driver_exit(void)
{platform_driver_unregister(&test_driver);
}
​
module_init(platform_driver_init);
module_exit(platform_driver_exit);
MODULE_LICENSE("Dual BSD/GPL");

四、设备树匹配之led驱动

五、一个编写驱动用的宏

struct platform_driver xxx = {  ...
};
module_platform_driver(xxx);
//最终展开后就是如下形式：
static int __init xxx_init(void)
{return platform_driver_register(&xxx);
}
module_init(xxx_init);
static void __exit xxx_init(void)
{return platform_driver_unregister(&xxx);
}
module_exit(xxx_exit)

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