text: /****************************************************************************
   * include/nuttx/usb/usbhost_devaddr.h
   * Manage USB device addresses
   *
   *   Copyright (C) 2013, 2015 Gregory Nutt. All rights reserved.
   *   Author: Gregory Nutt <gnutt@nuttx.org>
   *
   * NOTE:  This interface was inspired by the Linux gadget interface by
   * David Brownell. That work was very helpful in determining a usable
   * partitioning of functionality between standard class drivers and various
   * implementations of USB controller drivers.  This work, however, does
   * not derive directly from that work and is licensed differently.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   * 3. Neither the name NuttX nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ****************************************************************************/
  
  #ifndef __INCLUDE_NUTTX_USB_USBHOST_DEVADDR_H
  #define __INCLUDE_NUTTX_USB_USBHOST_DEVADDR_H
  
  /****************************************************************************
   * Included Files
   ****************************************************************************/
  
  #include <nuttx/config.h>
  
  #include <stdint.h>
  
  #include <nuttx/semaphore.h>
  
  /****************************************************************************
   * Pre-processor Definitions
   ****************************************************************************/
  
  /* Configuration ************************************************************/
  
  #define USBHOST_DEVADDR_HASHSIZE 8
  #define USBHOST_DEVADDR_HASHMASK (USBHOST_DEVADDR_HASHSIZE - 1)
  
  /****************************************************************************
   * Public Types
   ****************************************************************************/
  
  struct usbhost_devaddr_s
  {
    uint8_t   next;           /* Next device address */
    sem_t     exclsem;        /* Enforces mutually exclusive access */
    uint32_t  alloctab[4];    /* Bit allocation table */
  };
  
  /****************************************************************************
   * Public Data
   ****************************************************************************/
  
  #undef EXTERN
  #if defined(__cplusplus)
  #  define EXTERN extern "C"
  extern "C"
  {
  #else
  #  define EXTERN extern
  #endif
  
  /****************************************************************************
   * Public Functions Definitions
   ****************************************************************************/
  
  struct usbhost_hubport_s;     /* Forward reference */
  struct usbhost_roothubport_s; /* Forward reference */
  
  /****************************************************************************
   * Name: usbhost_devaddr_initialize
   *
   * Description:
   *   Initialize the caller provided struct usbhost_devaddr_s instance in
   *   preparation for the management of device addresses on behalf of an root
   *   hub port.
   *
   * Input Parameters:
   *   rhport - A reference to a roothubport structure.
   *
   * Returned Value:
   *   None
   *
   ****************************************************************************/
  
  void usbhost_devaddr_initialize(FAR struct usbhost_roothubport_s *rhport);
  
  /****************************************************************************
   * Name: usbhost_devaddr_create
   *
   * Description:
   *   Create a new unique device address for this hub port.
   *
   * Input Parameters:
   *   hport - A reference to a hub port structure to which a device has been
   *     newly connected and so is in need of a function address.
   *
   * Returned Value:
   *   On success, a new device function address in the range 0x01 to 0x7f
   *   is returned.  On failure, a negated errno value is returned.
   *
   ****************************************************************************/
  
  int usbhost_devaddr_create(FAR struct usbhost_hubport_s *hport);
  
  /****************************************************************************
   * Name: usbhost_devaddr_destroy
   *
   * Description:
   *  Release a device address previously assigned by usbhost_devaddr_create().
   *
   * Input Parameters:
   *  hport - A reference to a hub port structure from which a device has been
   *     disconnected and so no longer needs the function address.
   *  devaddr - The address to be released.
   *
   * Returned Value:
   *   None
   *
   ****************************************************************************/
  
  void usbhost_devaddr_destroy(FAR struct usbhost_hubport_s *hport,
                               uint8_t devaddr);
  
  #undef EXTERN
  #if defined(__cplusplus)
  }
  #endif
  
  #endif /* __INCLUDE_NUTTX_USB_USBHOST_DEVADDR_H */
  