编写超声波模块底层驱动运行应用程序出现下面问题？求版主解答？谢谢！

运行应用程序出现下面问题：

底层驱动已经在附件了，麻烦大家看看！
学习下定时器0 和中断的使用！

-----------------drive open ok----------------
-----------------init_timer0 ok----------------
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c3060000
[00000000] *pgd=33044031, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#2]
Modules linked in: EmbedSky_gpio ultrasonic driver_time ov9650 ds18b20v3 8192cu mac80211 input_polldev [last unloaded: ultrasonic]
CPU: 0    Tainted: G      D     (2.6.30.4-EmbedSky #1)
PC is at init_timer0+0x20/0xc0 [ultrasonic]
LR is at release_console_sem+0x18c/0x1e4
pc : [<bf0d00d8>]    lr : [<c0056688>]    psr: 60000013
sp : c3027f18  ip : 00000000  fp : c3027f2c
r10: 00000000  r9 : c3026000  r8 : c0044008
r7 : 00000003  r6 : c3027f78  r5 : 00010769  r4 : bf0d0c48
r3 : ffffffff  r2 : c04852c0  r1 : bf0d0394  r0 : 00000033
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: c000717f  Table: 33060000  DAC: 00000015
Process timer (pid: 695, stack limit = 0xc3026268)
Stack: (0xc3027f18 to 0xc3028000)
7f00:                                                       c305be00 00010769
7f20: c3027f44 c3027f30 bf0d0188 bf0d00c8 c305be00 00010769 c3027f54 c3027f48
7f40: bf0d022c bf0d0188 c3027f74 c3027f58 c00a5448 bf0d022c 00000000 00000000
7f60: c305be00 00000003 c3027fa4 c3027f78 c00a5560 c00a53a4 00000000 00000000
7f80: ffffffff 00000000 000083e4 00008518 00000000 000083e4 00000000 c3027fa8
7fa0: c0043e60 c00a5524 00008518 00000000 00000003 00010769 00000002 00000003
7fc0: 00008518 00000000 000083e4 00000003 00000000 00000000 40025000 bebefbe4
7fe0: 00000000 bebefbd0 000084fc 400f047c 60000010 00000003 30572031 30572431
Backtrace:
[<bf0d00b8>] (init_timer0+0x0/0xc0 [ultrasonic]) from [<bf0d0188>] (csb_proc+0x10/0xa4 [ultrasonic])
r5:00010769 r4:c305be00
[<bf0d0178>] (csb_proc+0x0/0xa4 [ultrasonic]) from [<bf0d022c>] (s3c2440_csb_read+0x10/0x44 [ultrasonic])
r5:00010769 r4:c305be00
[<bf0d021c>] (s3c2440_csb_read+0x0/0x44 [ultrasonic]) from [<c00a5448>] (vfs_read+0xb4/0xe8)
[<c00a5394>] (vfs_read+0x0/0xe8) from [<c00a5560>] (sys_read+0x4c/0x84)
r7:00000003 r6:c305be00 r5:00000000 r4:00000000
[<c00a5514>] (sys_read+0x0/0x84) from [<c0043e60>] (ret_fast_syscall+0x0/0x2c)
r6:000083e4 r5:00000000 r4:00008518
Code: e59f00a0 eb49e86b e594c004 e59f1098 (e59c3000)
---[ end trace dd7581f050069f39 ]---
-----------------drive close ok----------------
Segmentation fault

看来没人回答，算了，我自己回答！
主要是写的寄存器忘记映射地址了！这个方法很好，以后直接操作寄存器，最好的方式了！底层驱动直接操作寄存器！呵呵！