linux驱动分离分层的概念

这个分离分层的概念和输入子系统有点像，但不是完全一样的。为什么会再弄一个这个模型出来我也没有搞懂，现在我的学习还停留在把知识学懂的层面上。至于为什么会产生这种知识，现在我还无从解释，还需时日成长。

这次先上代码在解释整体构架。

devic.c

#include <linux/module.h>
#include <linux/version.h>#include <linux/init.h>#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/init.h>
#include <linux/serial_core.h>
#include <linux/platform_device.h>static void led_release(struct device * dev)
{
}static struct resource led_resource[] = {[0] = {.start = 0x56000010,             /* TQ2440的LED是GPB5,6,7,8, GPBCON地址是0x56000010 */.end   = 0x56000010 + 8 - 1,.flags = IORESOURCE_MEM,},[1] = {.start = 5,                      /* LED1 */.end   = 5,.flags = IORESOURCE_IRQ,}
};//首先要声明这么一个结构体   并且填充里面的一些东西     name是很重要的  
//它是两个文件相互匹配的依据     第二总要的就是resource   这个是声明你的硬件资源的
static struct platform_device led_dev = {.name      =         "myled",.id           =         -1,.num_resources    = ARRAY_SIZE(led_resource),.resource     = led_resource,.dev = { .release = led_release, },};static int  led_dev_init(void)
{platform_device_register(&led_dev);return 0;
}static void led_dev_exit(void)
{platform_device_unregister(&led_dev);return ;
}module_init(led_dev_init);
module_exit(led_dev_exit);
MODULE_LICENSE("GPL");

drive.c

#include <linux/module.h>
#include <linux/version.h>#include <linux/init.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/sysctl.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/irq.h>
#include <asm/uaccess.h>
#include <asm/io.h>static struct class *cls;
static struct class_device    *dev;
static volatile unsigned long *gpio_con;
static volatile unsigned long *gpio_dat;
static int pin;
int major;static int led_open(struct inode *inode, struct file *file)
{*gpio_con &= ~(0x3<<(pin*2));*gpio_con |= (0x1<<(pin*2));return 0;    
}static ssize_t led_write(struct file *file, const char __user *buf, size_t count, loff_t * ppos)
{int val;//printk("first_drv_write\n");
copy_from_user(&val, buf, count); //    copy_to_user();if (val == 1){// 点灯*gpio_dat &= ~(1<<pin);}else{// 灭灯*gpio_dat |= (1<<pin);}return 0;
}static struct file_operations led_fops = {.owner  =   THIS_MODULE,    /* 这是一个宏，推向编译模块时自动创建的__this_module变量 */.open   =   led_open,     .write    =    led_write,       
};static int led_probe(struct platform_device *pdev)
{printk("led_probe!\n");/*从这里获取在dev文件里面注册的资源*/struct resource * res;res = platform_get_resource(pdev, IORESOURCE_MEM, 0);gpio_con = ioremap(res->start, res->end - res->start + 1);gpio_dat = gpio_con + 1;res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);pin = res->start;/*回到前面的驱动程序，注册字符设备驱动程序*/major = register_chrdev(0, "myled", &led_fops);cls = class_create(THIS_MODULE, "myled");dev = class_device_create(cls, NULL, MKDEV(major, 0), NULL, "led");return 0;
}static int led_remove(struct platform_device *pdev)
{printk("led_remove!\n");class_device_unregister(dev);class_destroy(cls);unregister_chrdev(major, "myled");iounmap(gpio_con);return 0;
}///填充 这个结构体
struct platform_driver led_drv = {.probe        = led_probe,.remove        = led_remove,.driver        = {.name    = "myled",}
};static int led_drv_init(void)
{platform_driver_register(&led_drv);return 0;
}static void led_drv_exit(void)
{platform_driver_unregister(&led_drv);return ;
}module_init(led_drv_init);
module_exit(led_drv_exit);MODULE_LICENSE("GPL");