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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_streaming_terminal_get PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* Chaoqiong Xiao, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function searches and retrieves the streaming terminal. This */
/* terminal is used to further search which of the input\output */
/* terminals describes if the device is audio IN or audio OUT. */
/* */
/* INPUT */
/* */
/* audio Pointer to audio class */
/* */
/* OUTPUT */
/* */
/* Completion Status */
/* */
/* CALLS */
/* */
/* _ux_utility_descriptor_parse Parse descriptor */
/* */
/* CALLED BY */
/* */
/* Audio Class */
/* */
/**************************************************************************/
UINT _ux_host_class_audio_streaming_terminal_get(UX_HOST_CLASS_AUDIO *audio)
{
UCHAR * descriptor;
UX_INTERFACE_DESCRIPTOR interface_descriptor;
UX_HOST_CLASS_AUDIO_STREAMING_INTERFACE_DESCRIPTOR streaming_interface_descriptor;
ULONG total_descriptor_length;
ULONG descriptor_length;
ULONG descriptor_type;
ULONG descriptor_subtype;
ULONG descriptor_found;
/* Get the descriptor to the entire configuration */
descriptor = audio -> ux_host_class_audio_configuration_descriptor;
total_descriptor_length = audio -> ux_host_class_audio_configuration_descriptor_length;
/* Default is Interface descriptor not yet found. */
descriptor_found = UX_FALSE;
audio -> ux_host_class_audio_terminal_link = 0xffffffff;
/* Scan the descriptor for the Audio Streaming interface. */
while (total_descriptor_length)
{
/* Gather the length, type and subtype of the descriptor. */
descriptor_length = *descriptor;
descriptor_type = *(descriptor + 1);
descriptor_subtype = *(descriptor + 2);
/* Make sure this descriptor has at least the minimum length. */
if (descriptor_length < 3)
{
/* Error trap. */
_ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
/* If trace is enabled, insert this event into the trace buffer. */
UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
return(UX_DESCRIPTOR_CORRUPTED);
}
/* Process relative to the descriptor type. */
switch(descriptor_type)
{
case UX_INTERFACE_DESCRIPTOR_ITEM:
/* Parse the interface descriptor and make it machine independent. */
_ux_utility_descriptor_parse(descriptor, _ux_system_interface_descriptor_structure,
UX_INTERFACE_DESCRIPTOR_ENTRIES, (UCHAR *) &interface_descriptor);
/* Ensure we have the correct interface for Audio streaming. */
if ((interface_descriptor.bInterfaceClass == UX_HOST_CLASS_AUDIO_CLASS) &&
(interface_descriptor.bInterfaceSubClass == UX_HOST_CLASS_AUDIO_SUBCLASS_STREAMING) &&
(interface_descriptor.bInterfaceNumber == audio -> ux_host_class_audio_streaming_interface -> ux_interface_descriptor.bInterfaceNumber))
/* Mark we have found it. */
descriptor_found = UX_TRUE;
else
descriptor_found = UX_FALSE;
break;
case UX_HOST_CLASS_AUDIO_CS_INTERFACE:
/* First make sure we have found the correct generic interface descriptor. */
if (descriptor_found == UX_TRUE)
{
/* Check the sub type. */
switch(descriptor_subtype)
{
case UX_HOST_CLASS_AUDIO_CS_AS_GENERAL:
/* Make the descriptor machine independent. */
_ux_utility_descriptor_parse(descriptor, _ux_system_class_audio_streaming_interface_descriptor_structure,
UX_HOST_CLASS_AUDIO_STREAMING_INTERFACE_DESCRIPTOR_ENTRIES, (UCHAR *) &streaming_interface_descriptor);
/* Save the terminal link. */
audio -> ux_host_class_audio_terminal_link = streaming_interface_descriptor.bTerminalLink;
return(UX_SUCCESS);
}
}
break;
}
/* Verify if the descriptor is still valid. */
if (descriptor_length > total_descriptor_length)
{
/* Error trap. */
_ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
/* If trace is enabled, insert this event into the trace buffer. */
UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
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;
}
/* Error trap. */
_ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_HOST_CLASS_AUDIO_WRONG_TYPE);
/* We get here when either the report descriptor has a problem or we could
not find the right audio device. */
return(UX_HOST_CLASS_AUDIO_WRONG_TYPE);
}
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