求助: ldd3里边的scull 驱动的问题。。

ldy2534

1. 
   
2. #include <linux/cdev.h>
   
3. #include <linux/init.h>
   
4. #include <linux/module.h>
   
5. #include <linux/types.h>
   
6. #include <linux/fs.h>
   
7. #include <linux/kernel.h>
   
8. #include <asm/uaccess.h>
   
9. 
   
10. MODULE_LICENSE("Dual BSD/GPL");
    
11. /*scull simple character utility for loading localities*/
    
12. 
    
13. struct scull_qset {
    
14.         void **data;
    
15.         struct scull_qset *next;
    
16. };
    
17. 
    
18. struct scull_dev {
    
19.         struct scull_qset *data;
    
20.         int quantum;
    
21.         int qset;
    
22.         unsigned long size;
    
23.         unsigned int access_key;
    
24.         struct semaphore sem;
    
25. 
    
26.         struct cdev cdev;
    
27. };
    
28. 
    
29. int scull_open(struct inode *inode, struct file *filp);
    
30. ssize_t scull_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos);
    
31. ssize_t scull_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos);
    
32. int scull_release(struct inode *inode, struct file *filp);
    
33. 
    
34. int scull_major = 0;
    
35. static dev_t dev_num;
    
36. int scull_minor = 0;
    
37. int scull_nr_devs = 0;
    
38. struct file_operations scull_fops = {
    
39.         .owner = THIS_MODULE,
    
40.         .open = scull_open,
    
41.         .read = scull_read,
    
42.         .write = scull_write,
    
43.         .release = scull_release,
    
44.         .llseek = NULL,
    
45.         .ioctl = NULL,
    
46. };
    
47. 
    
48. int scull_release(struct inode *inode, struct file *filp)
    
49. {
    
50.         return 0;
    
51. }
    
52. 
    
53. int scull_open(struct inode *inode, struct file *filp)
    
54. {
    
55.         printk("scull open\n");
    
56. 
    
57.         return 0;
    
58. }
    
59. 
    
60. ssize_t scull_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)
    
61. {
    
62.         printk("scull read\n");
    
63.         return 0;
    
64. }
    
65. 
    
66. ssize_t scull_write(struct file *filp, const char __user *buf, size_t count, loff_t *f_pos)
    
67. {
    
68.         printk("scull write\n");
    
69.         return 0;
    
70. }
    
71. 
    
72. static int scull_init(void)
    
73. {
    
74.         printk("scull init\n");
    
75.         struct scull_dev scull_dev;
    
76.         int result, err;
    
77.         if (scull_major) {
    
78.                 dev_num = MKDEV(scull_major, scull_minor);
    
79.                 result = register_chrdev_region(dev_num, scull_nr_devs, "scull");
    
80.         } else {
    
81.                 result = alloc_chrdev_region(&dev_num, scull_minor, scull_nr_devs, "scull");
    
82.                 scull_major = MAJOR(dev_num);
    
83.         }
    
84.         if (result < 0) {
    
85.                 //printk(KERN_WARNING "scull: can't get major %d\n", scull_major);
    
86.                 printk("scull: can't get major %d\n", scull_major);
    
87.                 return result;
    
88.         }
    
89.         //scull_setup_cdev(&scull_dev, 1);
    
90.         cdev_init(&scull_dev.cdev, &scull_fops);
    
91.         scull_dev.cdev.owner = THIS_MODULE;
    
92.         //dev->cdev.ops = &scull_fops;   //jason mark : not need.
    
93.         printk("cdev num is %d\n", MAJOR(dev_num), MINOR(dev_num));
    
94.         err = cdev_add(&scull_dev.cdev, dev_num, 1);
    
95. 
    
96.         if (err)
    
97.                 printk("--->JASON scull setup cdev err is %d\n", err);
    
98.         return 0;
    
99. }
    
100. 
     
101. static void scull_exit(void)
     
102. {
     
103.         printk("dev major and minor is %d, %d\n", MAJOR(dev_num), MINOR(dev_num));
     
104.         unregister_chrdev_region(dev_num, 1);
     
105.         printk("scull exit\n");
     
106. }
     
107. 
     
108. module_init(scull_init);
     
109. module_exit(scull_exit);
     
110. 
     

复制代码

1. #include <stdio.h>
   
2. #include <stdlib.h>
   
3. #include <string.h>
   
4. #include <unistd.h>
   
5. #include <sys/types.h>
   
6. #include <sys/stat.h>
   
7. #include <fcntl.h>
   
8. 
   
9. int main(void)
   
10. {
    
11.         int fd, ret;
    
12.         char *buf = "a scull test";
    
13.         char readbuf[30];
    
14. 
    
15.         memset(readbuf, 0, 30);
    
16.         fd = open("dev/scull", O_RDWR);
    
17.         if (fd < 0) {
    
18.                 printf("fd is error\n");
    
19.                 return 1;
    
20.         }
    
21.                
    
22.         ret = write(fd, buf, strlen(buf) + 1);
    
23.         if (ret < 0) {
    
24.                 printf("ret is not goodd\n");
    
25.                 return 1;
    
26.         }
    
27.         close(fd);
    
28. 
    
29.         fd = open("dev/scull", O_RDONLY);
    
30.         ret = read(fd, readbuf, 30);
    
31.         printf("%s\n", readbuf);
    
32.         close(fd);
    
33. 
    
34.         return(0);
    
35. }
    

复制代码

#makefile :

obj-m := scull.o
KERNELDIR := /lib/modules/2.6.20.20/build
PWD :=$(shell pwd)

modules:
        $(MAKE) -C $(KERNELDIR) M=$(PWD) modules

modules_install:
        $(MAKE) -C $(KERNELDIR) M=$(PWD) modules_install

test_scull: test_scull.c
        @gcc -o test_scull test_scull.c

clean :
        rm -rf *.ko
        rm -rf *.cmd
        rm -rf *.o




我之行的过程是 ：
1。 insmod scull.ko
2.   mknod /dev/scull 253 c 0
3.   ./test_scull


但结果是fd is error , log 信息里边看到 init 又成功，分配的major 是253， 但没有看到open 的信息。。
弄了两天了没弄出来，， 大家帮帮忙。。


原来代码很多的，我简化了一些，方便大家看，但也应该看到open的信息阿。。

[ 本帖最后由 ldy2534 于 2008-1-4 12:16 编辑 ]

scutan

fd = open("dev/scull", O_RDWR);
仔细看看你的路径, 是不是少了什么.

ldy2534

谢谢了。。。。可以了。。