/*************************************************************************** * Copyright (c) 2024 Microsoft Corporation * Copyright (c) 2026-present Eclipse ThreadX contributors * * 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 */ /** */ /** Audio Class */ /** */ /**************************************************************************/ /**************************************************************************/ /* Include necessary system files. */ #define UX_SOURCE_CODE #include "ux_api.h" #include "ux_host_class_audio.h" #include "ux_host_stack.h" /**************************************************************************/ /* */ /* FUNCTION RELEASE */ /* */ /* _ux_host_class_audio_descriptors_parse PORTABLE C */ /* 6.3.0 */ /* AUTHOR */ /* */ /* Chaoqiong Xiao, Microsoft Corporation */ /* */ /* DESCRIPTION */ /* */ /* This function parses all interface descriptors and their audio */ /* class specific descriptors relates to current audio instance. */ /* */ /* The function scans the device configuration descriptor. Once the */ /* interface descriptors of the audio instance are found, each audio */ /* 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 */ /* */ /* audio Pointer to audio instance */ /* parse_function Parse function for each */ /* audio class descriptor */ /* arg Parse function argument */ /* */ /* OUTPUT */ /* */ /* Completion Status */ /* */ /* CALLS */ /* */ /* CALLED BY */ /* */ /* Audio Class */ /* Application */ /* */ /**************************************************************************/ UINT _ux_host_class_audio_descriptors_parse(UX_HOST_CLASS_AUDIO *audio, UINT(*parse_function)(VOID *arg, UCHAR *packed_interface_descriptor, UCHAR *packed_endpoint_descriptor, UCHAR *packed_audio_descriptor), VOID* arg) { UCHAR *descriptor; UCHAR *interface_descriptor; UCHAR *endpoint_descriptor; ULONG ac_interface, as_interface; ULONG total_descriptor_length; ULONG descriptor_length; ULONG descriptor_type; UINT status; /* Ensure the instance is valid. */ if (_ux_host_stack_class_instance_verify(_ux_system_host_class_audio_name, (VOID *) audio) != UX_SUCCESS) { /* Error trap. */ _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_HOST_CLASS_INSTANCE_UNKNOWN); /* If trace is enabled, insert this event into the trace buffer. */ UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_HOST_CLASS_INSTANCE_UNKNOWN, audio, 0, 0, UX_TRACE_ERRORS, 0, 0) return(UX_HOST_CLASS_INSTANCE_UNKNOWN); } /* Device state check. */ if (audio -> ux_host_class_audio_device -> ux_device_state != UX_DEVICE_CONFIGURED) return(UX_INVALID_STATE); /* Get the descriptor to the selected format. */ descriptor = audio -> ux_host_class_audio_configuration_descriptor; total_descriptor_length = audio -> ux_host_class_audio_configuration_descriptor_length; /* Get target interface number of control/streaming. */ ac_interface = audio -> ux_host_class_audio_control_interface_number; as_interface = audio -> ux_host_class_audio_streaming_interface -> ux_interface_descriptor.bInterfaceNumber; /* Haven't found interface, endpoint yet. */ interface_descriptor = UX_NULL; endpoint_descriptor = UX_NULL; /* Scan the descriptor for the Audio Control/Streaming interface. */ while (total_descriptor_length) { /* Gather the length, type and subtype of the descriptor. */ descriptor_length = *descriptor; /* Make sure this descriptor has at least the minimum length. */ if (descriptor_length < 3) return(UX_DESCRIPTOR_CORRUPTED); descriptor_type = *(descriptor + 1); /* Process relative to descriptor type. */ switch (descriptor_type) { case UX_INTERFACE_DESCRIPTOR_ITEM: /* Ensure we have the correct interface for Audio Control/Streaming. */ if (descriptor[2] == ac_interface || descriptor[2] == as_interface) { /* Mark we have found it. */ interface_descriptor = descriptor; } else { /* Haven't found it. */ interface_descriptor = UX_NULL; } break; case UX_ENDPOINT_DESCRIPTOR_ITEM: /* Log endpoint descriptor for following CS_ENDPOINT. */ endpoint_descriptor = descriptor; break; case UX_HOST_CLASS_AUDIO_CS_ENDPOINT: case UX_HOST_CLASS_AUDIO_CS_INTERFACE: /* Have we found the audio interface yet? */ if (interface_descriptor != UX_NULL) { /* Yes, parse the audio specific descriptor. */ status = parse_function(arg, interface_descriptor, endpoint_descriptor, descriptor); /* Terminate the parsing if status is not 0. */ if (status) { /* Parsing terminated by user, it's OK. */ return(UX_SUCCESS); } } break; default: 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_audio_descriptors_parse PORTABLE C */ /* 6.3.0 */ /* AUTHOR */ /* */ /* Chaoqiong Xiao, Microsoft Corporation */ /* */ /* DESCRIPTION */ /* */ /* This function checks errors in audio descriptors parse function */ /* call. */ /* */ /* INPUT */ /* */ /* audio Pointer to audio instance */ /* parse_function Parse function for each */ /* audio class descriptor */ /* arg Parse function argument */ /* */ /* OUTPUT */ /* */ /* Status */ /* */ /* CALLS */ /* */ /* _uxe_host_class_audio_descriptors_parse */ /* Parse audio descriptors */ /* */ /* CALLED BY */ /* */ /* Application */ /* */ /**************************************************************************/ UINT _uxe_host_class_audio_descriptors_parse(UX_HOST_CLASS_AUDIO *audio, UINT(*parse_function)(VOID *arg, UCHAR *packed_interface_descriptor, UCHAR *packed_endpoint_descriptor, UCHAR *packed_audio_descriptor), VOID* arg) { /* Sanity checks. */ if ((audio == UX_NULL) || (parse_function == UX_NULL)) return(UX_INVALID_PARAMETER); /* Invoke audio descriptor parse function. */ return(_ux_host_class_audio_descriptors_parse(audio, parse_function, arg)); }