Camera problem about LicheePI zero (uboot+bsp camera ov2640)

```
# fswebcam -d /dev/video1 --no-banner -r 320x240 capture.jpg
--- Opening /dev/video1...
[   30.700188] [VFE]vfe_open
Trying source module v4l2...[   30.706141] [VFE]..........................vfe clk open!.......................

[   30.717867] [VFE]vfe_open ok
[   30.721604] [VFE]Set vfe core clk = 108000000, after Set vfe core clk = 99000000
/dev/video1 opened.
No input was specified, using the first.
[   30.760033] [VFE]mclk on
[   30.850853] [VFE_ERR]sensor initial error when selecting target device!
[   30.858730] [VFE]vfe_close
Error selecting input 0
   30.862129] [VFE]mclk off
1mVIDIOC_S_INPUT: Operation not permitted
[   30.912095] [VFE]..........................vfe clk close!.......................
[   30.920689] [VFE]vfe_close end
```

I used the kernel and driver compiled by the official linux3.4 sdk, I can recognize ov2640 but can’t take photos.

http://dl.sipeed.com/LICHEE/Zero/Images/
But I used the image of this website to identify it directly, so I don’t know what went wrong.
Who told me what I should change, I probably understand the problem of the kernel and the driver, but I don’t know where to start.