90 lines
2.3 KiB
C
90 lines
2.3 KiB
C
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#include <linux/types.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/module.h>
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#include <linux/device.h>
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#include <linux/cdev.h>
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dev_t hello_dev_id;
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struct cdev hello_cdev;
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int hello_major = 0;
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int hello_minor;
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uint8_t kernel_buffer[1024] = { 0 };
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static struct class *hello_driver_class;
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static int hello_driver_open(struct inode *inode, struct file *file)
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{
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printk("hello_driver_open\r\n");
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return 0;
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}
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static int hello_driver_release(struct inode *inode, struct file *file)
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{
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printk("hello_driver_release\r\n");
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return 0;
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}
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static ssize_t hello_driver_read(struct file *file, char __user *buffer, size_t size, loff_t *ppos)
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{
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printk("hello_driver_read size=%ld\r\n", size);
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copy_to_user(buffer, kernel_buffer, size);
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return size;
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}
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static ssize_t hello_driver_write(struct file *file, const char __user *buffer, size_t size, loff_t *ppos)
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{
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printk("hello_driver_write size=%ld\r\n", size);
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copy_from_user(kernel_buffer, buffer, size);
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return size;
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}
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static const struct file_operations hello_driver_fops = {
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.owner = THIS_MODULE,
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.open = hello_driver_open,
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.release = hello_driver_release,
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.read = hello_driver_read,
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.write = hello_driver_write,
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};
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static int __init hello_driver_init(void)
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{
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printk("hello_driver_init\r\n");
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/* automatically apply for device number */
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alloc_chrdev_region(&hello_dev_id, 0, 1, "hello_driver");
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hello_major = MAJOR(hello_dev_id);
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hello_minor = MINOR(hello_dev_id);
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printk("hello_driver: major=%d, minor=%d\r\n", hello_major, hello_minor);
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hello_cdev.owner = THIS_MODULE;
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cdev_init(&hello_cdev, &hello_driver_fops);
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cdev_add(&hello_cdev, hello_dev_id, 1);
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// ret = register_chrdev(CHRDEVBASE_MAJOR, "hello_driver", &hello_driver_fops);
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/* automatically add device node file */
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hello_driver_class = class_create("hello_driver_class");
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device_create(hello_driver_class, NULL, hello_dev_id, NULL, "hello_driver_device");
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return 0;
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}
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static void __exit hello_driver_exit(void)
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{
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printk("hello_driver_exit\r\n");
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cdev_del(&hello_cdev);
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unregister_chrdev_region(hello_dev_id, 1);
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device_destroy(hello_driver_class, hello_dev_id);
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class_destroy(hello_driver_class);
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// unregister_chrdev(CHRDEVBASE_MAJOR, "hello_driver");
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}
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module_init(hello_driver_init);
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module_exit(hello_driver_exit);
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MODULE_LICENSE("GPL");
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