/*
    ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio.

    This file is part of ChibiOS.

    ChibiOS is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.

    ChibiOS is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/**
 * @defgroup IO_BLOCK Abstract I/O Block Device
 * @ingroup HAL_INTERFACES
 *
 * @section io_block_1 Driver State Machine
 * The drivers implementing this interface shall implement the following
 * state machine internally. Not all the driver functionalities can be used
 * in any moment, any transition not explicitly shown in the following
 * diagram has to be considered an error and shall be captured by an
 * assertion (if enabled).
 * @if LATEX_PDF
 * @dot
  digraph example {
    size="5, 7";
    rankdir="LR";

    node [shape=circle, fontname=Sans, fontsize=8, fixedsize="true", width="0.9", height="0.9"];
    edge [fontname=Sans, fontsize=8];

    stop  [label="BLK_STOP\nLow Power"];
    uninit [label="BLK_UNINIT", style="bold"];
    active [label="BLK_ACTIVE\nClock Enabled"];
    connecting [label="BLK_CONN.ING\nConnecting"];
    disconnecting [label="BLK_DISC.ING\nDisconnecting"];
    ready [label="BLK_READY\nCard Ready"];
    reading [label="BLK_READING\nReading"];
    writing [label="BLK_WRITING\nWriting"];

    uninit -> stop [label=" blkInit()", constraint=false];
    stop -> stop [label="\nblkStop()"];
    stop -> active [label="\nblkStart()"];
    active -> stop [label="\nblkStop()"];
    active -> active [label="\nblkStart()\nblkDisconnect()"];
    active -> connecting [label="\nblkConnect()"];
    connecting -> ready [label="\nconnection\nsuccessful"];
    connecting -> ready [label="\nblkConnect()", dir="back"];
    connecting -> active [label="\nconnection\nfailed"];
    disconnecting -> ready [label="\nblkDisconnect()", dir="back"];
    active -> disconnecting [label="\ndisconnection\nfinished", dir="back"];
    ready -> reading [label="\nblkRead()"];
    reading -> ready [label="\nread finished\nread error"];
    ready -> writing [label="\nblkWrite()"];
    writing -> ready [label="\nwrite finished\nwrite error"];
  }
 * @enddot
 * @else
 * @dot
  digraph example {
    rankdir="LR";

    node [shape=circle, fontname=Sans, fontsize=8, fixedsize="true", width="0.9", height="0.9"];
    edge [fontname=Sans, fontsize=8];

    stop  [label="BLK_STOP\nLow Power"];
    uninit [label="BLK_UNINIT", style="bold"];
    active [label="BLK_ACTIVE\nClock Enabled"];
    connecting [label="BLK_CONN.ING\nConnecting"];
    disconnecting [label="BLK_DISC.ING\nDisconnecting"];
    ready [label="BLK_READY\nCard Ready"];
    reading [label="BLK_READING\nReading"];
    writing [label="BLK_WRITING\nWriting"];
    syncing [label="BLK_SYNCING\nSynchronizing"];

    uninit -> stop [label=" blkInit()", constraint=false];
    stop -> stop [label="\nblkStop()"];
    stop -> active [label="\nblkStart()"];
    active -> stop [label="\nblkStop()"];
    active -> active [label="\nblkStart()\nblkDisconnect()"];
    active -> connecting [label="\nblkConnect()"];
    connecting -> ready [label="\nconnection\nsuccessful"];
    connecting -> ready [label="\nblkConnect()", dir="back"];
    connecting -> active [label="\nconnection\nfailed"];
    disconnecting -> ready [label="\nblkDisconnect()", dir="back"];
    active -> disconnecting [label="\ndisconnection\nfinished", dir="back"];
    ready -> reading [label="\nblkRead()"];
    reading -> ready [label="\nread finished\nread error"];
    ready -> writing [label="\nblkWrite()"];
    writing -> ready [label="\nwrite finished\nwrite error"];
    ready -> syncing [label="\nblkSync()"];
    syncing -> ready [label="\nsynchronization finished"];
  }
 * @enddot
 * @endif
 */