text: /**************************************************************************/
  /*                                                                        */
  /*       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 HID Class                                                    */
  /**                                                                       */
  /**************************************************************************/
  /**************************************************************************/
  
  #define UX_SOURCE_CODE
  
  
  /* Include necessary system files.  */
  
  #include "ux_api.h"
  #include "ux_device_class_hid.h"
  #include "ux_device_stack.h"
  
  
  /**************************************************************************/
  /*                                                                        */
  /*  FUNCTION                                               RELEASE        */
  /*                                                                        */
  /*    _ux_device_class_hid_report_get                     PORTABLE C      */
  /*                                                           6.1          */
  /*  AUTHOR                                                                */
  /*                                                                        */
  /*    Chaoqiong Xiao, Microsoft Corporation                               */
  /*                                                                        */
  /*  DESCRIPTION                                                           */
  /*                                                                        */
  /*    This function returns a report to the host.                         */
  /*                                                                        */
  /*  INPUT                                                                 */
  /*                                                                        */
  /*    descriptor_type                       Descriptor type               */
  /*    descriptor_index                      Index of descriptor           */
  /*    host_length                           Length requested by host      */
  /*                                                                        */
  /*  OUTPUT                                                                */
  /*                                                                        */
  /*    Completion Status                                                   */ 
  /*                                                                        */
  /*  CALLS                                                                 */ 
  /*                                                                        */ 
  /*    _ux_device_class_hid_event_get        Get HID event                 */
  /*    _ux_device_stack_transfer_request     Process transfer request      */
  /*    _ux_utility_memory_set                Set memory                    */
  /*    _ux_utility_memory_copy               Copy memory                   */
  /*                                                                        */ 
  /*  CALLED BY                                                             */ 
  /*                                                                        */ 
  /*    Application                                                         */ 
  /*    Device Stack                                                        */
  /*                                                                        */ 
  /*  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_hid_report_get(UX_SLAVE_CLASS_HID *hid, ULONG descriptor_type, 
                                              ULONG request_index, ULONG host_length)
  {
  
  UX_SLAVE_DEVICE                 *device;
  UX_SLAVE_TRANSFER               *transfer_request;
  UX_SLAVE_ENDPOINT               *endpoint;
  UCHAR                           report_id;
  UCHAR                           report_type;
  UX_SLAVE_CLASS_HID_EVENT        hid_event;
  ULONG                           hid_event_length;
  UCHAR                           *buffer;
  UINT                            status =  UX_ERROR;
  
      UX_PARAMETER_NOT_USED(descriptor_type);
      UX_PARAMETER_NOT_USED(request_index);
  
      /* If trace is enabled, insert this event into the trace buffer.  */
      UX_TRACE_IN_LINE_INSERT(UX_TRACE_DEVICE_CLASS_HID_REPORT_GET, hid, descriptor_type, request_index, 0, UX_TRACE_DEVICE_CLASS_EVENTS, 0, 0)
  
      /* Get the pointer to the device.  */
      device =  &_ux_system_slave -> ux_system_slave_device;
      
      /* Get the control endpoint associated with the device.  */
      endpoint =  &device -> ux_slave_device_control_endpoint;
  
      /* Get the pointer to the transfer request associated with the endpoint.  */
      transfer_request =  &endpoint -> ux_slave_endpoint_transfer_request;
  
      /* Get report ID (wValue.lower) and report type (wValue.higher).  */
      report_id   = *(transfer_request -> ux_slave_transfer_request_setup + UX_SETUP_VALUE + 0);
      report_type = *(transfer_request -> ux_slave_transfer_request_setup + UX_SETUP_VALUE + 1);
  
      /* Set the direction to OUT.  */
      transfer_request -> ux_slave_transfer_request_phase =  UX_TRANSFER_PHASE_DATA_OUT;
  
      /* Prepare the event data payload from the hid event structure.  Get a pointer to the buffer area.  */
      buffer =  transfer_request -> ux_slave_transfer_request_data_pointer;
  
      /* Initialize event fields.  */
      hid_event.ux_device_class_hid_event_report_id   = report_id;
      hid_event.ux_device_class_hid_event_report_type = report_type;
      hid_event.ux_device_class_hid_event_length      = UX_DEVICE_CLASS_HID_EVENT_BUFFER_LENGTH;
  
      /* If it's input report without ID try to get it from event queue head.  */
      if (report_type == UX_DEVICE_CLASS_HID_REPORT_TYPE_INPUT &&
          hid -> ux_device_class_hid_report_id != UX_TRUE)
  
          /* Check if we have an event to report.  */
          status = _ux_device_class_hid_event_get(hid, &hid_event);
  
      /* Try to get event from application callback.  */
      else
      {
          
          /* Let application fill event.  */
          if (hid -> ux_device_class_hid_get_callback != UX_NULL)
              status = hid -> ux_device_class_hid_get_callback(hid, &hid_event);
      }
  
      if (status == UX_SUCCESS)
      {
  
          /* Get the length to send back to the host.  */
          if (host_length < hid_event.ux_device_class_hid_event_length)
              hid_event_length =  host_length;
          else
              hid_event_length =  hid_event.ux_device_class_hid_event_length;
          if (hid_event_length > UX_SLAVE_REQUEST_CONTROL_MAX_LENGTH)
              hid_event_length = UX_SLAVE_REQUEST_CONTROL_MAX_LENGTH;
  
          /* First reset it.  */
          _ux_utility_memory_set(buffer, 0, hid_event_length); /* Use case of memset is verified. */
  
          /* Copy the event buffer into the target buffer.  */
          _ux_utility_memory_copy(buffer, hid_event.ux_device_class_hid_event_buffer, hid_event_length); /* Use case of memcpy is verified. */
      }
      else
      {
  
          /* There's no event, so send back zero'd memory.  */
  
          /* Get the length to send back to the host.  */
          if (host_length < UX_SLAVE_REQUEST_CONTROL_MAX_LENGTH)
              hid_event_length =  host_length;
          else
              hid_event_length =  UX_SLAVE_REQUEST_CONTROL_MAX_LENGTH;
  
          /* Reset it.  */
          _ux_utility_memory_set(buffer, 0, hid_event_length); /* Use case of memset is verified. */
      }
  
      /* We can send the report.  */
      status =  _ux_device_stack_transfer_request(transfer_request, hid_event_length, host_length);
  
      /* Return the status to the caller.  */
      return(status);
  }
  
  