text: /**
   * Copyright (c) 2016 - 2021, Nordic Semiconductor ASA
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without modification,
   * are permitted provided that the following conditions are met:
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   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form, except as embedded into a Nordic
   *    Semiconductor ASA integrated circuit in a product or a software update for
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   *
   * 3. Neither the name of Nordic Semiconductor ASA nor the names of its
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   *
   * 4. This software, with or without modification, must only be used with a
   *    Nordic Semiconductor ASA integrated circuit.
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   */
  
  #ifndef APP_USBD_CORE_H__
  #define APP_USBD_CORE_H__
  
  #include <stdint.h>
  
  #include "sdk_common.h"
  #include "nrf_drv_usbd.h"
  #include "app_usbd_types.h"
  #include "app_usbd_class_base.h"
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  
  /**
   * @defgroup app_usbd_core USB Device high level library core module
   * @ingroup app_usbd
   *
   * @brief @tagAPI52840 Core module that manages current USB state and process device requests.
   * @{
   */
  
  /**
   * @brief Core interface configuration.
   *
   * Core instance would have 2 endpoints (IN0 and OUT0).
   * The interface number does not matter because it is not used.
   */
  #define APP_USBD_CORE_CLASS_CONFIGURATION ((0, NRF_DRV_USBD_EPOUT0, NRF_DRV_USBD_EPIN0))
  
  /**
   * @brief USB Device state.
   *
   * Possible USB Device states according to specification.
   */
  typedef enum
  {
      APP_USBD_STATE_Disabled  , /**< The whole USBD library is disabled */
      APP_USBD_STATE_Unattached, /**< Device is currently not connected to the host */
      APP_USBD_STATE_Powered   , /**< Device is connected to the host but has not been enumerated */
      APP_USBD_STATE_Default   , /**< USB Reset condition detected, waiting for the address */
      APP_USBD_STATE_Addressed , /**< Device has been addressed but has not been configured */
      APP_USBD_STATE_Configured, /**< Device is addressed and configured */
  }app_usbd_state_t;
  
  /**
   * @brief EP0 handler function pointer.
   *
   * Type of the variable that would hold the pointer to the handler for
   * endpoint 0 messages processing.
   *
   * @param p_contex Context variable configured with the transmission request.
   */
  typedef ret_code_t (*app_usbd_core_setup_data_handler_t)(nrf_drv_usbd_ep_status_t status,
                                                           void const * p_context);
  
  /**
   * @brief Variable type used to register EP0 transfer handler.
   *
   * EP0 messages are processed by core instance.
   * Another class can register itself to receive messages from EP0 when requesting
   * for Setup data transfer.
   */
  typedef struct
  {
      app_usbd_core_setup_data_handler_t   handler;   //!< Event handler to be called when transmission is ready
      void const                         * p_context; //!< Context pointer to be send to every called event.
  } app_usbd_core_setup_data_handler_desc_t;
  
  /*lint -save -e10 -e26 -e93 -e123 -e505 */
  /**
   * @brief Declare Core instance type.
   *
   * USBD core instance type definition.
   */
  APP_USBD_CLASS_TYPEDEF(app_usbd_core,
          APP_USBD_CORE_CLASS_CONFIGURATION,
          APP_USBD_CLASS_INSTANCE_SPECIFIC_DEC_NONE,
          APP_USBD_CLASS_DATA_SPECIFIC_DEC_NONE);
  /*lint -restore*/
  
  /**
   * @brief Access to core instance.
   *
   * Function that returns pointer to the USBD core instance.
   *
   * @return pointer to the core instance.
   */
  #pragma GCC diagnostic push
  #pragma GCC diagnostic ignored "-Wnested-externs"
  static inline app_usbd_class_inst_t const * app_usbd_core_instance_access(void)
  {
      extern const APP_USBD_CLASS_INSTANCE_TYPE(app_usbd_core) app_usbd_core_inst;
      return (app_usbd_class_inst_t const *)&app_usbd_core_inst;
  }
  #pragma GCC diagnostic pop
  
  /**
   * @brief Enable endpoint 0
   *
   * Function enables endpoint OUT0 and IN0.
   * This makes the USB respond to SETUP transfers.
   */
  void app_usbd_core_ep0_enable(void);
  
  /**
   * @brief Disable endpoint 0
   *
   * Function disables endpoint OUT0 and IN0.
   * This makes the USB ignore SETUP transfers.
   */
  void app_usbd_core_ep0_disable(void);
  
  /**
   * @brief Default simple response to setup command.
   *
   * This function generates default simple response.
   * It sends ZLP when required and on takes care on allowing status stage when
   * transfer is finished.
   *
   * @param p_setup Pointer to original setup message.
   * @param p_data  Pointer to the response. This has to be globaly aviable data.
   * @param size    Total size of the answer - The function takes care about
   *                limiting the size of transfered data to the size required
   *                by setup command.
   */
  ret_code_t app_usbd_core_setup_rsp(app_usbd_setup_t const * p_setup,
                                     void const *             p_data,
                                     size_t                   size);
  
  /**
   * @brief Configure the handler for the nearest setup data endpoint transfer.
   *
   * This function would be called on incomming setup data.
   * The correct place to set the handler for a data is when SETUP command
   * was received.
   *
   * @param ep             Endpoint number (only IN0 and OUT0 are supported).
   * @param p_handler_desc Descriptor of the handler to be called.
   *
   * @retval NRF_SUCCESS            Successfully configured.
   * @retval NRF_ERROR_INVALID_ADDR Last received setup direction does not match
   *                                configured endpoint.
   */
  ret_code_t app_usbd_core_setup_data_handler_set(
      nrf_drv_usbd_ep_t ep,
      app_usbd_core_setup_data_handler_desc_t const * const p_handler_desc);
  
  /**
   * @brief Set up a data transfer buffer.
   *
   * Returns special internal buffer that can be used in setup transfer.
   * @return Internal buffer pointer.
   */
  void * app_usbd_core_setup_transfer_buff_get(size_t * p_size);
  
  
  /**@brief Return internal USBD core state.
   *
   * @return Check @ref app_usbd_state_t to find possible USBD core states.
   */
  app_usbd_state_t app_usbd_core_state_get(void);
  
  
  /**
   * @brief Check current feature state.
   *
   * Function checks the state of the selected feature that was configured by the host.
   *
   * @param feature Feature to check. @ref app_usbd_setup_stdfeature_t
   *                Only features related to the device should be checked by this function.
   *
   * @retval true  Selected feature is set.
   * @retval false Selected feature is cleared.
   */
  bool app_usbd_core_feature_state_get(app_usbd_setup_stdfeature_t feature);
  
  /** @} */
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* APP_USBD_CORE_H__ */
  