/*************************************************************************** * Copyright (c) 2024 Microsoft Corporation * * This program and the accompanying materials are made available under the * terms of the MIT License which is available at * https://opensource.org/licenses/MIT. * * SPDX-License-Identifier: MIT **************************************************************************/ /**************************************************************************/ /**************************************************************************/ /** */ /** USBX Component */ /** */ /** Video Class */ /** */ /**************************************************************************/ /**************************************************************************/ /* Include necessary system files. */ #define UX_SOURCE_CODE #include "ux_api.h" #include "ux_host_class_video.h" #include "ux_host_stack.h" /**************************************************************************/ /* */ /* FUNCTION RELEASE */ /* */ /* _ux_host_class_video_entities_parse PORTABLE C */ /* 6.1.12 */ /* AUTHOR */ /* */ /* Chaoqiong Xiao, Microsoft Corporation */ /* */ /* DESCRIPTION */ /* */ /* This function parsees all interface descriptors and their video */ /* class specific descriptors. */ /* */ /* The function scans the device configuration descriptor. Once the */ /* interface descriptors of the video instance are found, each video */ /* class descriptors belong to the interface are passed to parse */ /* function for caller one by one to parse. The interface descriptor */ /* is also passed to provide more information. Another pointer to */ /* arguments is also available as parse function parameter for caller */ /* to pass necessary caller specific data to process in parse function.*/ /* */ /* The descriptor parsing can be terminated by returning non-zero */ /* code in parse function. */ /* */ /* INPUT */ /* */ /* video Pointer to video instance */ /* parse_function Parse function for each */ /* video class descriptor */ /* arg Parse function argument */ /* */ /* OUTPUT */ /* */ /* Completion Status */ /* */ /* CALLS */ /* */ /* CALLED BY */ /* */ /* Video Class */ /* Application */ /* */ /* RELEASE HISTORY */ /* */ /* DATE NAME DESCRIPTION */ /* */ /* 09-30-2020 Chaoqiong Xiao Initial Version 6.1 */ /* 08-02-2021 Wen Wang Modified comment(s), */ /* fixed spelling error, */ /* resulting in version 6.1.8 */ /* 07-29-2022 Chaoqiong Xiao Modified comment(s), */ /* fixed parameter/variable */ /* names conflict C++ keyword, */ /* resulting in version 6.1.12 */ /* */ /**************************************************************************/ UINT _ux_host_class_video_entities_parse(UX_HOST_CLASS_VIDEO *video, UINT(*parse_function)(VOID *arg, UCHAR *packed_interface_descriptor, UCHAR *packed_entity_descriptor), VOID* arg) { UCHAR *descriptor; UCHAR *interface_descriptor; UX_INTERFACE *interface_ptr; ULONG total_descriptor_length; ULONG descriptor_length; ULONG descriptor_type; UINT status; /* Device state check. */ if (video -> ux_host_class_video_device -> ux_device_state != UX_DEVICE_CONFIGURED) return(UX_HOST_CLASS_VIDEO_DEVICE_NOT_READY); /* Get the descriptor to the selected format. */ descriptor = video -> ux_host_class_video_configuration_descriptor; total_descriptor_length = video -> ux_host_class_video_configuration_descriptor_length; /* Haven't found interface yet. */ interface_descriptor = UX_NULL; /* Scan the descriptor for the Video Streaming interface. */ while (total_descriptor_length) { /* Gather the length, type and subtype of the descriptor. */ descriptor_length = *descriptor; descriptor_type = *(descriptor + 1); /* Make sure this descriptor has at least the minimum length. */ if (descriptor_length < 3) return(UX_DESCRIPTOR_CORRUPTED); /* Process relative to descriptor type. */ switch (descriptor_type) { case UX_INTERFACE_DESCRIPTOR_ITEM: /* Haven't found it. */ interface_descriptor = UX_NULL; /* Ensure we have the correct interface for Video Control/Streaming. */ if (descriptor[5] == UX_HOST_CLASS_VIDEO_CLASS) { /* VideoControl Interface. */ if (descriptor[6] == UX_HOST_CLASS_VIDEO_SUBCLASS_CONTROL) /* Mark we have found it. */ interface_descriptor = descriptor; else { /* VideoStreaming interface, currently only one supported. */ interface_ptr = video -> ux_host_class_video_streaming_interface; if (descriptor[2] == interface_ptr -> ux_interface_descriptor.bInterfaceNumber) /* Mark we have found it. */ interface_descriptor = descriptor; } } break; case UX_HOST_CLASS_VIDEO_CS_INTERFACE: /* Have we found the video interface yet? */ if (interface_descriptor != UX_NULL) { /* Yes, parse the entity descriptor. */ status = parse_function(arg, interface_descriptor, descriptor); /* Terminate the parsing if status is not 0. */ if (status) return(UX_SUCCESS); } break; } /* Verify if the descriptor is still valid. */ if (descriptor_length > total_descriptor_length) return(UX_DESCRIPTOR_CORRUPTED); /* Jump to the next descriptor if we have not reached the end. */ descriptor += descriptor_length; /* And adjust the length left to parse in the descriptor. */ total_descriptor_length -= descriptor_length; } /* We get here when all descriptors scanned. */ return(UX_SUCCESS); } /**************************************************************************/ /* */ /* FUNCTION RELEASE */ /* */ /* _uxe_host_class_video_entities_parse PORTABLE C */ /* 6.3.0 */ /* AUTHOR */ /* */ /* Yajun Xia, Microsoft Corporation */ /* */ /* DESCRIPTION */ /* */ /* This function checks errors in video entities parse function call. */ /* */ /* INPUT */ /* */ /* video Pointer to video instance */ /* parse_function Parse function for each */ /* video class descriptor */ /* arg Parse function argument */ /* */ /* OUTPUT */ /* */ /* Completion Status */ /* */ /* CALLS */ /* */ /* _ux_host_class_video_entities_parse Video entities parse */ /* */ /* CALLED BY */ /* */ /* Video Class */ /* Application */ /* */ /* RELEASE HISTORY */ /* */ /* DATE NAME DESCRIPTION */ /* */ /* 10-31-2023 Yajun xia Initial Version 6.3.0 */ /* */ /**************************************************************************/ UINT _uxe_host_class_video_entities_parse(UX_HOST_CLASS_VIDEO *video, UINT(*parse_function)(VOID *arg, UCHAR *packed_interface_descriptor, UCHAR *packed_entity_descriptor), VOID* arg) { /* Sanity checks. */ if (video == UX_NULL) return(UX_INVALID_PARAMETER); /* Call the actual video entities parse function. */ return(_ux_host_class_video_entities_parse(video, parse_function, arg)); }