/**************************************************************************/
/*                                                                        */
/*       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                                                        */ 
/**                                                                       */
/**   Device DPUMP Class                                                  */
/**                                                                       */
/**************************************************************************/
/**************************************************************************/

#define UX_SOURCE_CODE


/* Include necessary system files.  */

#include "ux_api.h"
#include "ux_device_class_dpump.h"
#include "ux_device_stack.h"


/**************************************************************************/ 
/*                                                                        */ 
/*  FUNCTION                                               RELEASE        */ 
/*                                                                        */ 
/*    _ux_device_class_dpump_read                         PORTABLE C      */ 
/*                                                           6.1          */
/*  AUTHOR                                                                */
/*                                                                        */
/*    Chaoqiong Xiao, Microsoft Corporation                               */
/*                                                                        */
/*  DESCRIPTION                                                           */
/*                                                                        */ 
/*    This function reads from the DPUMP class.                           */ 
/*                                                                        */ 
/*  INPUT                                                                 */ 
/*                                                                        */ 
/*    dpump                                   Address of dpump class      */ 
/*                                                instance                */ 
/*                                                                        */ 
/*  OUTPUT                                                                */ 
/*                                                                        */ 
/*    None                                                                */ 
/*                                                                        */ 
/*  CALLS                                                                 */ 
/*                                                                        */ 
/*    _ux_device_stack_transfer_request     Request transfer              */ 
/*    _ux_utility_memory_copy               Copy memory                   */ 
/*                                                                        */ 
/*  CALLED BY                                                             */ 
/*                                                                        */ 
/*    ThreadX                                                             */ 
/*                                                                        */ 
/*  RELEASE HISTORY                                                       */ 
/*                                                                        */ 
/*    DATE              NAME                      DESCRIPTION             */ 
/*                                                                        */ 
/*  05-19-2020     Chaoqiong Xiao           Initial Version 6.0           */
/*  09-30-2020     Chaoqiong Xiao           Modified comment(s),          */
/*                                            verified memset and memcpy  */
/*                                            cases,                      */
/*                                            resulting in version 6.1    */
/*                                                                        */
/**************************************************************************/
UINT _ux_device_class_dpump_read(UX_SLAVE_CLASS_DPUMP *dpump, UCHAR *buffer, 
                                ULONG requested_length, ULONG *actual_length)
{

UX_SLAVE_ENDPOINT           *endpoint;
UX_SLAVE_DEVICE             *device;
UX_SLAVE_TRANSFER           *transfer_request;
UINT                        status;
ULONG                       local_requested_length;

    /* If trace is enabled, insert this event into the trace buffer.  */
    UX_TRACE_IN_LINE_INSERT(UX_TRACE_DEVICE_CLASS_DPUMP_READ, dpump, buffer, requested_length, 0, UX_TRACE_DEVICE_CLASS_EVENTS, 0, 0)
  
    /* Get the pointer to the device.  */
    device =  &_ux_system_slave -> ux_system_slave_device;
    
    /* As long as the device is in the CONFIGURED state.  */
    if (device -> ux_slave_device_state != UX_DEVICE_CONFIGURED)
    {        
    
        /* Error trap. */
        _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_CONFIGURATION_HANDLE_UNKNOWN);

        /* If trace is enabled, insert this event into the trace buffer.  */
        UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_CONFIGURATION_HANDLE_UNKNOWN, device, 0, 0, UX_TRACE_ERRORS, 0, 0)

        /* Cannot proceed with command, the interface is down.  */
        return(UX_CONFIGURATION_HANDLE_UNKNOWN);
    }
        
    /* Locate the OUT endpoint.  */
    endpoint =  dpump -> ux_slave_class_dpump_bulkout_endpoint;
    
    /* Check endpoint. If NULL, we have not yet received the proper SET_INTERFACE command.  */
    if (endpoint == UX_NULL)
    {
        /* Error trap. */
        _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_ENDPOINT_HANDLE_UNKNOWN);

        return(UX_ENDPOINT_HANDLE_UNKNOWN);
    }
    
    /* All DPUMP reading  are on the endpoint OUT, from the host.  */
    transfer_request =  &endpoint -> ux_slave_endpoint_transfer_request;
    
    /* Reset the actual length.  */
    *actual_length =  0;
    
    /* Set return status to SUCCESS to make certain compilers happy.  */
    status =  UX_SUCCESS;
    
    /* Check if we need more transactions.  */
    while (device -> ux_slave_device_state == UX_DEVICE_CONFIGURED && requested_length != 0)
    { 
        
        /* Check if we have enough in the local buffer.  */
        if (requested_length > UX_SLAVE_REQUEST_DATA_MAX_LENGTH)
    
            /* We have too much to transfer.  */
            local_requested_length = UX_SLAVE_REQUEST_DATA_MAX_LENGTH;
            
        else
        
            /* We can proceed with the demanded length.  */
            local_requested_length = requested_length;
        
        /* Send the request to the device controller.  */
        status =  _ux_device_stack_transfer_request(transfer_request, local_requested_length, local_requested_length);
        
        /* Check the status */    
        if (status == UX_SUCCESS)
        {

            /* We need to copy the buffer locally.  */
            _ux_utility_memory_copy(buffer, transfer_request -> ux_slave_transfer_request_data_pointer, 
                            local_requested_length); /* Use case of memcpy is verified. */
        
            /* Next buffer address.  */
            buffer += transfer_request -> ux_slave_transfer_request_actual_length;
    
            /* Set the length actually received. */
            *actual_length += transfer_request -> ux_slave_transfer_request_actual_length; 
    
            /* Decrement what left has to be done.  */
            requested_length -= transfer_request -> ux_slave_transfer_request_actual_length;
    
        }
        else
    
            /* We got an error.  */
            return(status);
    }

    /* Check why we got here, either completion or device was extracted.  */
    if (device -> ux_slave_device_state != UX_DEVICE_CONFIGURED)
    {        

        /* Error trap. */
        _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_TRANSFER_NO_ANSWER);

        /* If trace is enabled, insert this event into the trace buffer.  */
        UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_TRANSFER_NO_ANSWER, transfer_request, 0, 0, UX_TRACE_ERRORS, 0, 0)

        /* Device must have been extracted.  */
        return (UX_TRANSFER_NO_ANSWER);
    }
    else
    
        /* Simply return the last transaction result.  */
        return(status);        
}