求助：自己写的SPI设备驱动问题

自己写了一个SPI设备的驱动，加载驱动后已经成功调用probe函数并创建了设备文件，问题是现在应用程序打开设备文件后就出现以下错误：将驱动中的open函数与release函数中其它删除只留下打印信息，应用程序中只留下打开和关闭设备文件代码，还是会出现如下错误，麻烦大侠帮忙解决以下该问题（已经调试好久了还没解决）


Unable to handle kernel NULL pointer dereference at virtual address 0000002fe driver uvcv
usbcore:  
LR is at sys_close+0xa0/0xcc
pc : [<c0cde7c0>] lr : [<c0cde8d0>] psr: 80000013
sp : c082bf68 ip : c082bf88 fp : c082bf84
r10: 00000000 r9 : c082a000 r8 : c0c80008
r7 : 00000006 r6 : 0000001b r5 : c2b01cc0 r4 : 00000003
r3 : 00000007 r2 : 00000004 r1 : c2b01cc0 r0 : 0000001b
Flags: Nzcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: c000717f Table: 32b84000 DAC: 00000015
Process app_gp21 (pid: 504, stack limit = 0xc082a268)
Stack: (0xc082bf68 to 0xc082c000)
bf60: 00000003 c2b01cc0 0000001b 00000006 c082bfa4 c082bf88
bf80: c0cde8d0 c0cde7c4 0000b494 00000000 0000b450 00000006 00000000 c082bfa8
bfa0: c0c7fe60 c0cde840 0000b494 00000000 00000003 00000000 00084f2c 00000001
bfc0: 0000b494 00000000 0000b450 00000006 00000000 00000000 00000000 be851b94
bfe0: 00000000 be851b78 00008278 0001522c 60000010 00000003 e5803008 e542c001
Backtrace:
[<c0cde7b4>] (filp_close+0x0/0x7c) from [<c0cde8d0>] (sys_close+0xa0/0xcc)
r7:00000006 r6:0000001b r5:c2b01cc0 r4:00000003
[<c0cde830>] (sys_close+0x0/0xcc) from [<c0c7fe60>] (ret_fast_syscall+0x0/0x2c)
r7:00000006 r6:0000b450 r5:00000000 r4:0000b494
Code: e89da800 e1a0c00d e92dd8f0 e24cb004 (e5903014)
---[ end trace d982a507971a8f45 ]---
Segmentation fault

驱动程序主要代码如下：

1. #define ARRYSIZE(x) ( sizeof(x)/ sizeof(x[0]))
   
2. #define EINT3_IRQ 7
   
3. #define SPI_MAJOR 252
   
4. #define HIGH 1
   
5. #define LOW 0
   
6. 
   
7. 
   
8. extern int spi_register_driver(struct spi_driver *sdrv);
   
9. extern int spi_write_then_read(struct spi_device *spi,const u8 *txbuf,unsigned n_tx,u8 *rxbuf,unsigned n_rx);
   
10. extern int spi_sync(struct spi_device *spi,struct spi_message *message);
    
11. extern struct class *__class_creat(struct module *owner ,const char *name,struct lock_class_key *key);
    
12. extern int register_chrdev(unsigned int major,const char *name,const struct file_operations *fops);
    
13. 
    
14. 
    
15. 
    
16. 
    
17. static char ev_irq = 0; // 定义表示中断发生的变量
    
18. 
    
19. static DECLARE_WAIT_QUEUE_HEAD(measure_waitq); //定义一个等待队列
    
20. 
    
21. 
    
22. 
    
23. 
    
24.   struct spidev_data  
    
25. {
    
26.   dev_t devt;
    
27.   struct spi_device *spi ;
    
28. };
    
29. 
    
30. 
    
31. 
    
32.   irqreturn_t mp_interrupt (int irq ,void *dev_id)
    
33. {
    
34.   unsigned char value ;
    
35.   value = s3c2410_gpio_getpin(S3C2410_GPF3);   
    
36.   if (!value)
    
37.   {
    
38.   ev_irq = 1 ;
    
39.   wake_up_interruptible (&measure_waitq);
    
40.   }
    
41.    
    
42. }
    
43. 
    
44. 
    
45. 
    
46.   int Mp_Open (struct inode *inode ,struct file *file)
    
47. {
    
48.   /* struct spidev_data *data_spi ;
    
49.   file->private_data = data_spi ;   
    
50.   if (request_irq(EINT3_IRQ,mp_interrupt,IRQF_DISABLED|IRQF_TRIGGER_LOW,"mp",NULL)) //申请中断
    
51.   {
    
52.   printk ("request_irq error\n");
    
53. 
    
54. } */
    
55.    
    
56.   printk("kernel open device success\n");
    
57. }
    
58. 
    
59. 
    
60.    
    
61.   int Mp_Release (struct inode *inode ,struct file *filp)
    
62. {
    
63.   printk("close device\n");
    
64. 
    
65. 
    
66. 
    
67. }
    
68.   struct file_operations mp_fops =
    
69. {
    
70.   .owner = THIS_MODULE ,
    
71.   .open = Mp_Open ,
    
72.   .release = Mp_Release ,
    
73.    
    
74. };
    
75. 
    
76.   static struct class *spi_class ;
    
77. 
    
78. 
    
79. 
    
80. static int Mp_Probe (struct spi_device *spi_dev)
    
81. {
    
82.   int ret ;
    
83.   struct spidev_data *data_spi ;
    
84.   data_spi= kzalloc (sizeof(*data_spi),GFP_KERNEL);
    
85.   if(!data_spi)
    
86.   return -ENOMEM ;
    
87.   printk("kzalloc success\n");
    
88.   data_spi->spi = spi_dev ;
    
89.   data_spi->devt = MKDEV(SPI_MAJOR,0);  
    
90.   device_create(spi_class,&spi_dev->dev,data_spi->devt,data_spi,"mp");
    
91.   spi_set_drvdata(spi_dev,data_spi);  
    
92.   printk ("probe mp \n ");
    
93.   return 0 ;
    
94.    
    
95. }
    
96. 
    
97. 
    
98. static int Mp_Remove (struct spi_device *spi_dev)
    
99. {
    
100. 
     
101.   struct spidev_data *data_spi ;
     
102.   cdev_del (&data_spi->spi);//注销字符设备
     
103.   return 0 ;
     
104. 
     
105. 
     
106. }
     
107. 
     
108. 
     
109. static struct spi_driver mp_driver =
     
110. {
     
111.   .probe = Mp_Probe ,
     
112.   .remove = Mp_Remove ,
     
113.   .driver =
     
114.   {
     
115.   .name = "mp" ,
     
116.   .owner = THIS_MODULE ,
     
117.   }
     
118. 
     
119. } ;
     
120. 
     
121. 
     
122. 
     
123. static int __init Mp_init (void)
     
124. {
     
125.   unsigned int ret ;
     
126.   ret = register_chrdev(SPI_MAJOR,"spi",&mp_fops);
     
127.   if (ret<0)
     
128.   {
     
129.   printk ("cdev add error\n");
     
130.   return ret;
     
131.   }
     
132.   spi_class = class_create (THIS_MODULE,"mp");
     
133.   if (IS_ERR(spi_class))
     
134.   {
     
135.   return PTR_ERR(spi_class);
     
136.   }
     
137.   return spi_register_driver (&mp_driver);
     
138. 
     
139. }
     
140. 
     
141. static void __exit Mp_exit (void)
     
142. {
     
143.   spi_unregister_driver (&mp_driver);
     
144. }
     
145. 
     
146. 
     
147. 
     
148. module_init(Mp_init);
     
149. module_exit(Mp_exit);
     
150. MODULE_LICENSE("GPL");
     
151. MODULE_DESCRIPTION("mp for EmbedSky SKY2440/TQ2440 Board");
     

复制代码

应用程序如下：

1. void main (int argc ,char **argv)
   
2. {
   
3. int fd ;
   
4. fd = open("/dev/mp" ,O_RDWR);   
   
5. 
   
6. if (fd<0)
   
7. {
   
8.   printf ("open device error\n");
   
9.   return ;
   
10. }
    
11. 
    
12. printf ("open seccuss\n");   
    
13.   close(fd);
    
14. }
    
15. 
    
16. 
    
17. 
    

复制代码

是不是设备号重了？

如果你选择使用系统自带的SPI的框架，建议参考系统自带的针对S3C2410的那个SPI驱动。

设备号没有重复  ，查看/dev目录下自动创建的设备文件主设备号是252，参考了系统自带的spidev.c驱动文件，但是基本框架式一样的，不可能完全抄那个的，但是不知道具体哪一条语句造成这个问题