linux平台驱动编写初探

平台

cpu: s3c2410;
board： mini2440； 
网卡: dm9000;

注册平台设备驱动

static int __init mini2440_led_init(void)
{
 ……
  err = platform_driver_register(&mini2440_led_driver);
 ……
}

static void __exit mini2440_led_exit(void)
{ 
  platform_driver_unregister(&mini2440_led_driver);
}

module_init(mini2440_led_init);
module_exit(mini2440_led_exit);

上面的函数是用于注册平台driver的。
还要平台驱动所需要的platform_driver:

static struct platform_driver mini2440_led_driver = { 
    .probe      = s3c24xx_led_probe,
    .remove     = s3c24xx_led_remove,
    .driver     = { 
        .name       = "mini2440_led",
        .owner      = THIS_MODULE,
    },  
};

这样如果没有注册名为“mini2440_led”的平台设备，probe是不能够执行的。

注册平台设备

static struct s3c24xx_led_platdata mini2440_pdata_led0 = { 
	.gpio		= S3C2410_GPB5,
	.flags		= S3C24XX_LEDF_ACTLOW | S3C24XX_LEDF_TRISTATE,
	.name		= "mini2440_led5",
	.def_trigger	= "mini2440_led",
};

static struct s3c24xx_led_platdata mini2440_pdata_led1 = {
	.gpio		= S3C2410_GPB6,
	.flags		= S3C24XX_LEDF_ACTLOW | S3C24XX_LEDF_TRISTATE,
	.name		= "mini2440_led6",
	.def_trigger	= "mini2440_led",
};

static struct platform_device mini2440_led0 = {
	.name	= "mini2440_led",
	.id		= 0,
	.dev	= {
		.platform_data = &mini2440_pdata_led0,
	},
};

static struct platform_device mini2440_led1 = {
	.name		= "mini2440_led",
	.id		= 1,
	.dev		= {
		.platform_data = &mini2440_pdata_led1,
	},
};

static struct platform_device __initdata *mini2440_devs[] = {
	&mini2440_led0,
	&mini2440_led1,
};

由上面的struct可以看出将要注册两个led相关的平台设备mini2440_led，分别名为：mini2440_led5,mini2440_led6。
还需要把这两个设备注册到平台设备总线上：
使用函数：

platform_add_devices(mini2440_devs, ARRAY_SIZE(mini2440_devs));

由于有两个平台设备，所以平台驱动probe将会执行两次。

probe函数

static int s3c24xx_led_probe(struct platform_device *dev)；

remove函数

static int s3c24xx_led_remove(struct platform_device *dev)