Analog 的AD7476参考设计跑不起来 有偿求解

yt920419

https://wiki.analog.com/resources/fpga/xilinx/pmod/ad7476a
参考的AD7476a IPcore方法在Zedboard上运行IIO 程序，按照参考的git里的cf_ad7476_zed 搭建硬件平台时出现period anasys错误，将PL clock频率从150M降到100M可以完成Bit生成，按照参考里的方法制作BOOT.bin(u-boot2015), devicetree(pmod_ad1_ipcore),uImage(kernel4.0),然后展开linaro14.10，
板子上运行HDMI能显示，USB 能使用，IIO里能看到ad7476a的两个通道，但选择通道运行时 串口会打印出错误报告，分析了下报告原因是有空指针，
Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 1 PID: 1736 Comm: hexdump Not tainted 3.17.0 #1
task: df76a940 ti: df660000 task.ti: df660000
PC is at 0x0
LR is at iio_buffer_data_available+0x10/0x14

找了ad7476驱动C文件里没有操作这个地址，应该是iio的驱动问题，也没找到操作函数，完整log在最后面，麻烦大家给出点建议，LZ是新手，很多问题想不到，还请大家指教，能解决问题的回答LZ会奉上一点心意，谢谢~~
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = d6ab0000
[00000000] *pgd=16810831, *pte=00000000, *ppte=00000000
Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 1 PID: 1736 Comm: hexdump Not tainted 3.17.0 #1
task: df76a940 ti: df660000 task.ti: df660000
PC is at 0x0
LR is at iio_buffer_data_available+0x10/0x14
pc : [<00000000>]    lr : [<c03193b4>]    psr: a0030013
sp : df661f20  ip : c031a424  fp : 00015120
r10: 00001000  r9 : df660000  r8 : b6fa4000
r7 : df661f88  r6 : d6802280  r5 : df6d0800  r4 : df5b34c0
r3 : 00000000  r2 : 00001000  r1 : c045974c  r0 : df5b34c0
Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 18c5387d  Table: 16ab004a  DAC: 00000015
Process hexdump (pid: 1736, stack limit = 0xdf660240)
Stack: (0xdf661f20 to 0xdf662000)
1f20: c045e1e4 c031a46c 00000004 0d149ba0 0000007f d694b238 00000000 00000003
1f40: 00001000 d6802280 b6fa4000 df661f88 c000de84 df660000 00000000 c00b7a54
1f60: d6802280 b6fa4000 00001000 d6802280 d6802280 00001000 b6fa4000 c000de84
1f80: 00000000 c00b7c04 00000000 00000000 00001000 b6f94cb8 b6f93c04 b6f94cb8
1fa0: 00000003 c000dd00 b6f94cb8 b6f93c04 00000000 b6fa4000 00001000 00000000
1fc0: b6f94cb8 b6f93c04 b6f94cb8 00000003 00000010 00019820 000150e4 00015120
1fe0: 00000000 be8bc59c b6f0247f b6f3a916 40030030 00000000 00000000 00000000
[<c03193b4>] (iio_buffer_data_available) from [<c031a46c>] (iio_buffer_read_first_n_outer+0x48/0x14c)
[<c031a46c>] (iio_buffer_read_first_n_outer) from [<c00b7a54>] (vfs_read+0x94/0x128)
[<c00b7a54>] (vfs_read) from [<c00b7c04>] (SyS_read+0x40/0x78)
[<c00b7c04>] (SyS_read) from [<c000dd00>] (ret_fast_syscall+0x0/0x30)
Code: bad PC value
---[ end trace 9ffd6696733f40cc ]---
Segmentation fault
root@analog:/sys/bus/iio/devices/iio:device0/buffer#