camera daemon进程

int main(int argc, char *argv[])

{

  mct_list_t                *listen_fd_list = NULL;

  read_fd_info_t            *hal_fd = NULL, *hal_ds_fd = NULL, *mct_fds = NULL;

  server_select_fds_t       select_fds;

  struct v4l2_event         event;

  /* 1. find server node name and open the node */

  get_server_node_name(serv_hal_node_name;

  hal_fd->fd[0] = open(dev_name, O_RDWR | O_NONBLOCK);/****dev_name = dev/video0***/

  hal_fd->type = RD_FD_HAL;

  listen_fd_list = mct_list_append(listen_fd_list, hal_fd, NULL, NULL);/******/

  property_get("cameradaemon.SaveMemAtBoot", savemem, "0");

  enabled_savemem = atoi(savemem);

  /* 2. after open node, initialize modules */

  server_process_module_sensor_init();

  /***

  *server_process_module_sensor_init只是初始化了modules_list[0].init_mod(modules_list[0].name);即sensor

  ***/

  if (enabled_savemem != 1) {

    if (server_process_module_init() == FALSE);

     /***

     *for (i = 1; i < (int)(sizeof(modules_list)/sizeof(mct_module_init_name_t)); i++)

     *所以会初始化iface、isp、stats、pproc、imglib这五个模块

     ***/

    }

   /* Subcribe V4L2 event */

  subscribe.type = MSM_CAMERA_V4L2_EVENT_TYPE;

  ioctl(hal_fd->fd[0], VIDIOC_SUBSCRIBE_EVENT, &subscribe);/***函数分析1、2***/

  select_fds.select_fd = hal_fd->fd[0];

  CDBG("CAMERA_DAEMON:waiting for camera to open\n");

  do {

       FD_ZERO(&(select_fds.fds));

       mct_list_traverse(listen_fd_list, server_reset_select_fd, &select_fds); /***函数分析3***/

       ret = select(select_fds.select_fd + 1, &(select_fds.fds), NULL, NULL, NULL);  

       if (ret > 0)

        {

           mct_list_t     *find_list;

           read_fd_info_t *fd_info;

           find_list = mct_list_find_custom(listen_fd_list, &(select_fds.fds), server_check_listen_fd);

            /***通过select_fds.fds中被置1的fd找到对应的链表***/

           fd_info = (read_fd_info_t *)find_list->data;

           switch (fd_info->type) {

           case RD_FD_HAL: {

             if (ioctl(fd_info->fd[0], VIDIOC_DQEVENT, &event) < 0)

                continue;

           /* server process HAL event:

            *   1. if it returns success, it means the event message has been posted to MCT, don't need to send CMD ACK back to kernel

            *      immediately, because MCT will notify us after process;

            *

            *   2. if it returns failure, it means the event message was not posted to MCT successfully, hence we need to send CMD ACK back

            *      to kernel immediately so that HAL thread which sends this event can be blocked.

            */

              proc_ret = server_process_hal_event(&event);

            break;

          case RD_DS_FD_HAL:

          /* server process message sent by HAL through Domain Socket */

              proc_ret = server_process_hal_ds_packet(fd_info->fd[0],fd_info->session);

            break;

          case RD_PIPE_FD_MCT:

          /* server process message sent by media controller through pipe: */

            proc_ret = server_process_mct_msg(fd_info->fd[0],  fd_info->session);

            break;

          default:

             continue;

        } /* switch (fd_info->type) */    

    }while (1);

}

int camera_init_v4l2(struct device *dev, unsigned int *session)

{

    struct msm_video_device *pvdev;

    struct v4l2_device *v4l2_dev;

    pvdev->vdev->release  = video_device_release;

    pvdev->vdev->fops     = &camera_v4l2_fops;

    pvdev->vdev->ioctl_ops = &camera_v4l2_ioctl_ops;

    pvdev->vdev->minor     = -1;

    pvdev->vdev->vfl_type  = VFL_TYPE_GRABBER;

    rc = video_register_device(pvdev->vdev, VFL_TYPE_GRABBER, -1);

}