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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_role_swap PORTABLE C */
/* 6.1.10 */
/* AUTHOR */
/* */
/* Chaoqiong Xiao, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function is called when the host or the device demand a role */
/* swap. This function may be called by an application or by the HNP */
/* thread. */
/* */
/* INPUT */
/* */
/* hcd Pointer to HCD */
/* device Device pointer */
/* */
/* OUTPUT */
/* */
/* Status */
/* */
/* CALLS */
/* */
/* _ux_utility_semaphore_get Get semaphore */
/* _ux_host_stack_transfer_request Transfer request */
/* */
/* CALLED BY */
/* */
/* Application of HNP thread. */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */
/* 09-30-2020 Chaoqiong Xiao Modified comment(s), */
/* optimized based on compile */
/* definitions, */
/* resulting in version 6.1 */
/* 01-31-2022 Chaoqiong Xiao Modified comment(s), */
/* refined macros names, */
/* resulting in version 6.1.10 */
/* */
/**************************************************************************/
UINT _ux_host_stack_role_swap(UX_DEVICE *device)
{
#if !defined(UX_OTG_SUPPORT)
UX_PARAMETER_NOT_USED(device);
return(UX_FUNCTION_NOT_SUPPORTED);
#else
UX_ENDPOINT *control_endpoint;
UX_TRANSFER *transfer_request;
UINT status;
/* Retrieve the control endpoint and the transfer request associated with it. */
control_endpoint = &device -> ux_device_control_endpoint;
transfer_request = &control_endpoint -> ux_endpoint_transfer_request;
/* Protect the control endpoint semaphore here. It will be unprotected in the
transfer request function. */
status = _ux_host_semaphore_get(&device -> ux_device_protection_semaphore, UX_WAIT_FOREVER);
/* Perform a SET_FEATURE on this device to inform the it we are ready to change role. */
transfer_request -> ux_transfer_request_requested_length = 0;
transfer_request -> ux_transfer_request_function = UX_SET_FEATURE;
transfer_request -> ux_transfer_request_type = UX_REQUEST_OUT | UX_REQUEST_TYPE_STANDARD | UX_REQUEST_TARGET_DEVICE;
transfer_request -> ux_transfer_request_value = UX_OTG_FEATURE_B_HNP_ENABLE;
transfer_request -> ux_transfer_request_index = 0;
/* Send request to HCD layer. */
status = _ux_host_stack_transfer_request(transfer_request);
/* If the status fails, simply ignore the command but do not proceed. */
if (status != UX_SUCCESS)
/* We have an error. Do not proceed. */
return(status);
/* Keep track of the event for HNP synchronization. */
_ux_system_otg -> ux_system_otg_change_mode_event = UX_OTG_HOST_TO_SLAVE;
/* Call the OTG function that will perform the swap. */
_ux_system_otg -> ux_system_otg_function(UX_OTG_HOST_TO_SLAVE);
/* Reset the event. */
_ux_system_otg -> ux_system_otg_change_mode_event = 0;
return(UX_SUCCESS);
#endif
}