prgb problem in 2011 RRSDK

hi,

i want to use prgb driver to display video on lcd module.in my mind,i only need

fd = open("/sys/class/davinci_display/ch0/PRGB", O_RDWR);

and then like other display device such as composite,component :

 fmt.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
 if (format == 0) {
  width += 15;
  width &= (~15);
  fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_UYVY; 
 }
 else {
  width += 31;
  width &= (~31);
  fmt.fmt.pix.bytesperline = width;
  fmt.fmt.pix.sizeimage = width * height * 1.5;
  fmt.fmt.pix.pixelformat = V4L2_PIX_FMT_NV12; 
 }
 fmt.fmt.pix.height = height;
 fmt.fmt.pix.width = width;
 ret = ioctl(fd, VIDIOC_S_FMT, &fmt);
 if (ret) {
  perror("VIDIOC_S_FMT\n");
  close(fd);
  exit(1);
 }

 
 req.count = NUM_BUF;
 req.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
 req.memory = V4L2_MEMORY_USERPTR;

 ret = ioctl(fd, VIDIOC_REQBUFS, &req);
 if (ret) {
  perror("cannot allocate memory\n");
  close(fd);
  exit(1);
 }

 crop.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
 crop.c.top  = 0;
 crop.c.left = 0;
 crop.c.width= width;
 crop.c.height= height;

 ret = ioctl(fd, VIDIOC_S_CROP, &crop);
 if (ret) {
  perror("VIDIOC_S_CROP\n");
  close(fd);
  exit(0);
 }
 
 
 /* Enqueue buffers */
 for (i = 0; i < req.count; i++)
    {
  memcpy(display_buffer[i].user_addr, in_buf, size);
  bzero(&buf, sizeof(struct v4l2_buffer));
  buf.type = V4L2_BUF_TYPE_VIDEO_OUTPUT;
  buf.index = i;
  buf.memory = V4L2_MEMORY_USERPTR;
  buf.length = ALIGN(size, 4096);
  buf.m.userptr = display_buffer[i].user_addr;
  ret = ioctl(fd, VIDIOC_QBUF, &buf);
  //memset(buff_info[i].start,0xff,buff_info[i].length);
  if (ret)
         {
   perror("VIDIOC_QBUF\n");
   close(fd);
   exit(1);
  }
 }

 a = 0;
 ret = ioctl(fd, VIDIOC_STREAMON, &a);
 if (ret < 0)
     {
  perror("VIDIOC_STREAMON\n");
  close(fd);
  exit(1);
 }

 getchar();
 ret = ioctl(fd, VIDIOC_STREAMOFF, &a);
 if (ret) {
  perror("VIDIOC_STREAMOFF\n");
  close(fd);
  exit(1);
 }
 
 close(fd);

Am i right?any expert give me a light?

thanks