一：驅動基本框架
1：建立入口函式demo_init（）和出口函式demo_exit（）並用module_init（），module_exit（），module_license("gpl")函式進行註冊
二：填充驅動框架
1：入口函式中註冊裝置register_chrdev（），建立類class_create（）以及裝置節點class_device_create（）
2：建立入口函式中「註冊裝置」時所需的file_operations結構體demo_fops
static struct file_operations demo_fops
3：出口函式中刪除裝置節點class_device_unregister（），類class_destroy（），登出裝置unregister_chrdev（）
4：在file_operations中對應的介面函式中實現對硬體的操作
三：原始碼
1：drv.c
#include #include #include #include #include #include #include #include #include #include #include #include #include static struct class *demo_class;
static struct class_device *demo_class_dev;
// gpf0,2
volatile unsigned long *gpfcon;
volatile unsigned long *gpfdat;
// gpg3,11
volatile unsigned long *gpgcon;
volatile unsigned long *gpgdat;
static struct timer_list key_timer;
static declare_wait_queue_head(irq_waitq);
static volatile int ev_press = 0;
static struct fasync_struct *signal_fasync;
struct pin_desc;
struct pin_desc pins_desc[3] = ,,,
};static struct pin_desc *irq_pd;
#if 0 //定義原子操作
static atomic_t canopen = atomic_init(1);
#else //定義互斥鎖
static declare_mutex(key_lock);
#endif
static unsigned char key_val;
static irqreturn_t keys_irq(int irq, void *dev_id)
static int demo_open(struct inode *inode, struct file *file)
#else
if(file->f_flags & o_nonblock)// 非阻塞，獲取不到資源則立即返回
else
#endif
request_irq(irq_eint0, keys_irq, irqt_bothedge, "s2", &pins_desc[0]);
request_irq(irq_eint2, keys_irq, irqt_bothedge, "s3", &pins_desc[1]);
request_irq(irq_eint11, keys_irq, irqt_bothedge, "s4", &pins_desc[2]);
return 0;
}ssize_t demo_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
else
copy_to_user(buf, &key_val, 1);
ev_press = 0;
return 1;
}int demo_release(struct inode *inode, struct file *file)
static unsigned int demo_poll(struct file *file, struct poll_table_struct *wait)
static int demo_fasync(int fd, struct file *filp, int on)
static struct file_operations demo_fops =
;int major;
static void key_timer_fun(unsigned long time)
else
ev_press = 1;
wake_up_interruptible(&irq_waitq);
kill_fasync(&signal_fasync, sigio, poll_in);
}static int demo_init(void)
static void demo_exit(void)
module_init(demo_init);
module_exit(demo_exit);
module_license("gpl");
#include #include #include #include #include #include #include #include #include int fd;
void signal_fun(int signum)
int main(int argc, char **ar**)
fcntl(fd, f_setown, getpid()); //告訴核心
oflags = fcntl(fd, f_getfl);
fcntl(fd, f_setfl, oflags | fasync);//改變fasync，會呼叫驅動中的fasync函式指標對應的函式。
while (1)
return 0;
}
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