/**************************************************************************/ /* */ /* 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 */ /** */ /** ACM CDC Class */ /** */ /**************************************************************************/ /**************************************************************************/ /* Include necessary system files. */ #define UX_SOURCE_CODE #include "ux_api.h" #include "ux_host_class_cdc_acm.h" #include "ux_host_stack.h" /**************************************************************************/ /* */ /* FUNCTION RELEASE */ /* */ /* _ux_host_class_cdc_acm_read PORTABLE C */ /* 6.1.10 */ /* AUTHOR */ /* */ /* Chaoqiong Xiao, Microsoft Corporation */ /* */ /* DESCRIPTION */ /* */ /* This function reads from the cdc_acm interface. The call is */ /* blocking and only returns when there is either an error or when */ /* the transfer is complete. */ /* */ /* INPUT */ /* */ /* cdc_acm Pointer to cdc_acm class */ /* data_pointer Pointer to buffer */ /* requested_length Requested data read */ /* actual_length Actual data read */ /* */ /* OUTPUT */ /* */ /* Completion Status */ /* */ /* CALLS */ /* */ /* _ux_host_stack_transfer_request Process transfer request */ /* _ux_host_stack_transfer_request_abort Abort transfer request */ /* _ux_host_semaphore_get Get protection semaphore */ /* */ /* CALLED BY */ /* */ /* Application */ /* */ /* 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 */ /* 01-31-2022 Chaoqiong Xiao Modified comment(s), */ /* added standalone support, */ /* resulting in version 6.1.10 */ /* */ /**************************************************************************/ UINT _ux_host_class_cdc_acm_read (UX_HOST_CLASS_CDC_ACM *cdc_acm, UCHAR *data_pointer, ULONG requested_length, ULONG *actual_length) { UX_TRANSFER *transfer_request; UINT status; ULONG transfer_request_length; #if defined(UX_HOST_STANDALONE) ULONG transfer_flags; #endif /* If trace is enabled, insert this event into the trace buffer. */ UX_TRACE_IN_LINE_INSERT(UX_TRACE_HOST_CLASS_CDC_ACM_READ, cdc_acm, 0, 0, 0, UX_TRACE_HOST_CLASS_EVENTS, 0, 0) /* Ensure the instance is valid. */ if (cdc_acm -> ux_host_class_cdc_acm_state != UX_HOST_CLASS_INSTANCE_LIVE) { /* 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, cdc_acm, 0, 0, UX_TRACE_ERRORS, 0, 0) return(UX_HOST_CLASS_INSTANCE_UNKNOWN); } /* As further protection, we must ensure this instance of the interface is the data interface and not the control interface ! */ if (cdc_acm -> ux_host_class_cdc_acm_interface -> ux_interface_descriptor.bInterfaceClass != UX_HOST_CLASS_CDC_DATA_CLASS) { /* 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, cdc_acm, 0, 0, UX_TRACE_ERRORS, 0, 0) return(UX_HOST_CLASS_INSTANCE_UNKNOWN); } /* Start by resetting the actual length of the transfer to zero. */ *actual_length = 0; /* Get the pointer to the bulk in endpoint in the transfer_request. */ transfer_request = &cdc_acm -> ux_host_class_cdc_acm_bulk_in_endpoint -> ux_endpoint_transfer_request; #if defined(UX_HOST_STANDALONE) /* Enable auto wait. */ transfer_flags = transfer_request -> ux_transfer_request_flags; transfer_request -> ux_transfer_request_flags |= UX_TRANSFER_FLAG_AUTO_WAIT; #endif /* Perform a transfer on the bulk in endpoint until either the transfer is completed or until there is an error. */ while (requested_length) { /* Program the maximum authorized length for this transfer request. */ if (requested_length > transfer_request -> ux_transfer_request_maximum_length) transfer_request_length = transfer_request -> ux_transfer_request_maximum_length; else transfer_request_length = requested_length; /* Initialize the transfer request. */ transfer_request -> ux_transfer_request_data_pointer = data_pointer; transfer_request -> ux_transfer_request_requested_length = transfer_request_length; /* Perform the transfer. */ status = _ux_host_stack_transfer_request(transfer_request); /* If the transfer is successful, we need to wait for the transfer request to be completed. */ if (status == UX_SUCCESS) { #if !defined(UX_HOST_STANDALONE) /* Wait for the completion of the transfer_request. */ status = _ux_host_semaphore_get(&transfer_request -> ux_transfer_request_semaphore, transfer_request -> ux_transfer_request_timeout_value); /* If the semaphore did not succeed we probably have a time out. */ if (status != UX_SUCCESS) { /* All transfers pending need to abort. There may have been a partial transfer. */ _ux_host_stack_transfer_request_abort(transfer_request); /* Update the length of the actual data transferred. We do this after the abort of the transfer request in case some data was actually received. */ *actual_length += transfer_request -> ux_transfer_request_actual_length; /* Set the completion code. */ transfer_request -> ux_transfer_request_completion_code = UX_TRANSFER_TIMEOUT; /* Error trap. */ _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_TRANSFER_TIMEOUT); /* If trace is enabled, insert this event into the trace buffer. */ UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_TRANSFER_TIMEOUT, transfer_request, 0, 0, UX_TRACE_ERRORS, 0, 0) /* There was an error, return to the caller */ return(UX_TRANSFER_TIMEOUT); } #endif } else { #if defined(UX_HOST_STANDALONE) /* Update the length of the actual data transferred. We do this after the abort of the transfer request in case some data was actually received. */ *actual_length += transfer_request -> ux_transfer_request_actual_length; /* Restore previous setting. */ transfer_request -> ux_transfer_request_flags = transfer_flags; #endif /* There was a non transfer error, no partial transfer to be checked. */ return(status); } /* Update the length of the transfer. Normally all the data has to be received. */ *actual_length += transfer_request -> ux_transfer_request_actual_length; /* Check for completion of transfer. If the transfer is partial, return to caller. The transfer is marked as successful but the caller will need to check the length actually received and determine if a partial transfer is OK. */ if (transfer_request_length != transfer_request -> ux_transfer_request_actual_length) { /* Return success to caller. */ return(UX_SUCCESS); } /* Update the data pointer for next transfer. */ data_pointer += transfer_request_length; /* Update what is left to receive. */ requested_length -= transfer_request_length; } #if defined(UX_HOST_STANDALONE) /* Restore previous setting. */ transfer_request -> ux_transfer_request_flags = transfer_flags; #endif /* We get here when all the transfers went through without errors. */ return(UX_SUCCESS); }