uvc摄像头代码解析5(二)
ev, struct uvc_control *ctrl)
{
const struct uvc_control_info *info = uvc_ctrls; //指向全局静态uvc控制信息数组
const struct uvc_control_info *iend = info + ARRAY_SIZE(uvc_ctrls); //指向数组末端
const struct uvc_control_mapping *mapping = uvc_ctrl_mappings; //指向全局静态uvc控制位图数组
const struct uvc_control_mapping *mend = mapping + ARRAY_SIZE(uvc_ctrl_mappings); //指向数组末端
if (UVC_ENTITY_TYPE(ctrl->entity) == UVC_VC_EXTENSION_UNIT) //ctrl->entity->type为扩展Unit(延后扩展Unit的初始化到当它第一次使用)
return;
for (; info < iend; ++info) { //遍历整个uvc控制信息数据
if (uvc_entity_match_guid(ctrl->entity, info->entity) && ctrl->index == info->index) { //匹配条件
uvc_ctrl_add_info(dev, ctrl, info); //添加uvc控制信息
break;
}
}
if (!ctrl->initialized) //已经给初始化
return;
for (; mapping < mend; ++mapping) { //遍历整个uvc控制位图数组
if (uvc_entity_match_guid(ctrl->entity, mapping->entity) && ctrl->info.selector == mapping->selector) //匹配条件
__uvc_ctrl_add_mapping(dev, ctrl, mapping); //添加控制位图
}