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/**************************************************************************/
/* */
/* Copyright (c) Microsoft Corporation. All rights reserved. */
/* */
/* This software is licensed under the Microsoft Software License */
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
/* and in the root directory of this software. */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** USBX Component */
/** */
/** Host Stack */
/** */
/**************************************************************************/
/**************************************************************************/
/* Include necessary system files. */
#define UX_SOURCE_CODE
#include "ux_api.h"
#include "ux_host_stack.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _ux_host_stack_interfaces_scan PORTABLE C */
/* 6.1 */
/* AUTHOR */
/* */
/* Chaoqiong Xiao, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function scans all the interfaces and alternate settings for */
/* particular configuration. */
/* */
/* INPUT */
/* */
/* configuration Where the interface(s) will */
/* be attached */
/* descriptor Contains the entire descriptor*/
/* for this configuration */
/* */
/* OUTPUT */
/* */
/* None */
/* */
/* CALLS */
/* */
/* _ux_utility_descriptor_parse Parse interface descriptor */
/* _ux_host_stack_new_interface_create Create new interface */
/* */
/* CALLED BY */
/* */
/* USBX Components */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */
/* 09-30-2020 Chaoqiong Xiao Modified comment(s), */
/* resulting in version 6.1 */
/* */
/**************************************************************************/
UINT _ux_host_stack_interfaces_scan(UX_CONFIGURATION *configuration, UCHAR * descriptor)
{
ULONG total_configuration_length;
UINT descriptor_length;
UINT descriptor_type;
ULONG status;
ULONG interface_association_descriptor_present;
ULONG interface_in_iad_count;
UX_INTERFACE_ASSOCIATION_DESCRIPTOR interface_association;
/* Retrieve the size of all the configuration descriptor. */
total_configuration_length = configuration -> ux_configuration_descriptor.wTotalLength;
/* Set the IAD to false. */
interface_association_descriptor_present = UX_FALSE;
/* Set the IAD interface count to zero. */
interface_in_iad_count = 0;
/* Scan the entire descriptor and search for interfaces. We should also ensure that
the descriptor is valid by verifying the length of each descriptor scanned. */
while (total_configuration_length)
{
/* Gather the length and type of the descriptor. */
descriptor_length = *descriptor;
descriptor_type = *(descriptor + 1);
/* 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_ENUMERATOR, 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);
}
/* Check the type for an interface association descriptor. */
if (descriptor_type == UX_INTERFACE_ASSOCIATION_DESCRIPTOR_ITEM)
{
/* Parse the interface association descriptor and make it machine independent. */
_ux_utility_descriptor_parse(descriptor,
_ux_system_interface_association_descriptor_structure,
UX_INTERFACE_ASSOCIATION_DESCRIPTOR_ENTRIES,
(UCHAR *) &interface_association);
/* Retrieve the CLASS/SUBCLASS from descriptor and store it in the configuration instance. */
configuration -> ux_configuration_iad_class = interface_association.bFunctionClass;
configuration -> ux_configuration_iad_subclass = interface_association.bFunctionSubClass;
configuration -> ux_configuration_iad_protocol = interface_association.bFunctionProtocol;
/* We have an IAD. */
interface_association_descriptor_present = UX_TRUE;
/* Memorize the number of interfaces attached to this IAD. */
interface_in_iad_count = interface_association.bInterfaceCount;
}
/* Check the type for an interface descriptor. */
if (descriptor_type == UX_INTERFACE_DESCRIPTOR_ITEM)
{
/* We have found an interface descriptor. This descriptor contains at least
the default alternate setting (with value 0) and may have others. */
status = _ux_host_stack_new_interface_create(configuration, descriptor, total_configuration_length);
/* Are we within an IAD ? */
if (interface_association_descriptor_present == UX_TRUE)
{
/* Decrement the number of interfaces attached here. */
interface_in_iad_count--;
/* Are we at the end of the interface count ? */
if (interface_in_iad_count == 0)
{
/* Set the IAD to false now. */
interface_association_descriptor_present = UX_FALSE;
/* Reset the IAD Class/Subclass/Protocol. */
configuration -> ux_configuration_iad_class = 0;
configuration -> ux_configuration_iad_subclass = 0;
configuration -> ux_configuration_iad_protocol = 0;
}
}
/* Check return status. */
if(status != UX_SUCCESS)
return(status);
}
/* Check the type for an OTG descriptor. */
if (descriptor_type == UX_OTG_DESCRIPTOR_ITEM)
/* Retrieve the bmAttributes for SRP/HNP support. */
configuration -> ux_configuration_otg_capabilities = (ULONG) *(descriptor + UX_OTG_BM_ATTRIBUTES);
/* Verify if the descriptor is still valid. */
if (descriptor_length > total_configuration_length)
{
/* Error trap. */
_ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_ENUMERATOR, 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_configuration_length -= descriptor_length;
}
/* Return successful completion. */
return(UX_SUCCESS);
}