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/***************************************************************************
* 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));
}
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