ISP1761 USB driver

Hi,hippo

Do you know the possible reasons of the following phenomenon:

(a uclinux system had trasplanted into the board DE2 successful,and the usb camera can work)

I was programming for grabbling picture via video4liux API which was used for USB camer.

I can obtain the camera and the picture information using ioctl() function:

fd=open("dev/v4l/video0",O_RDWR);

...........

int cap=ioctl(fd,VIDIOCGCAP,& capability);

..........

int pic=ioctl(fd,VIDIOCGPICT,& picture);

return value:

fd=3;

cap=0;

pic=0;

Above code could work ,and the correct information was obtained.

but when used the following code ,a problem was generated

struct video_mbuf mbuf;

...........

struct video_mmap grab_buf;

grab_buf.frame=0;

grab_buf.height=240;

grab_buf.width=320;

grab_buf.format=VIDEO_PALETTE_RGB24;

char *data;

data=mmap(0,mbuf.size,PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);

..................

int grab=ioctl(fd,VIDIOCMCAPTURE,&grab_buf);

.................

int sync=ioctl(fd,VIDIOCSYNC,& grab_buf.frame);

.............

the return value:

data=-1

grab=-1;

sync=-1

That's to say ,the process of grabbing a frame_picture work failed!

do you know the possible reasons!

the isp1362 driver did not suppot the isochronous ,I have modified the parameter of the isp1362 driver,Now, there wasn't the note:Isochronous transfer not supportec.

Look forward to you reply! Thank you !