marlin/Marlin/SdVolume.h

/* Arduino SdFat Library
 * Copyright (C) 2009 by William Greiman
 *
 * This file is part of the Arduino SdFat Library
 *
 * This Library 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.
 *
 * This Library 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 the Arduino SdFat Library.  If not, see
 * <http://www.gnu.org/licenses/>.
 */
#ifndef SdVolume_h
#define SdVolume_h
/**
 * \file
 * \brief SdVolume class
 */
#include "SdFatConfig.h"
#include "Sd2Card.h"
#include "SdFatStructs.h"

//==============================================================================
// SdVolume class
/**
 * \brief Cache for an SD data block
 */
union cache_t {
           /** Used to access cached file data blocks. */
  uint8_t  data[512];
           /** Used to access cached FAT16 entries. */
  uint16_t fat16[256];
           /** Used to access cached FAT32 entries. */
  uint32_t fat32[128];
           /** Used to access cached directory entries. */
  dir_t    dir[16];
           /** Used to access a cached Master Boot Record. */
  mbr_t    mbr;
           /** Used to access to a cached FAT boot sector. */
  fat_boot_t fbs;
           /** Used to access to a cached FAT32 boot sector. */
  fat32_boot_t fbs32;
           /** Used to access to a cached FAT32 FSINFO sector. */
  fat32_fsinfo_t fsinfo;
};
//------------------------------------------------------------------------------
/**
 * \class SdVolume
 * \brief Access FAT16 and FAT32 volumes on SD and SDHC cards.
 */
class SdVolume {
 public:
  /** Create an instance of SdVolume */
  SdVolume() : fatType_(0) {}
  /** Clear the cache and returns a pointer to the cache.  Used by the WaveRP
   * recorder to do raw write to the SD card.  Not for normal apps.
   * \return A pointer to the cache buffer or zero if an error occurs.
   */
  cache_t* cacheClear() {
    if (!cacheFlush()) return 0;
    cacheBlockNumber_ = 0XFFFFFFFF;
    return &cacheBuffer_;
  }
  /** Initialize a FAT volume.  Try partition one first then try super
   * floppy format.
   *
   * \param[in] dev The Sd2Card where the volume is located.
   *
   * \return The value one, true, is returned for success and
   * the value zero, false, is returned for failure.  Reasons for
   * failure include not finding a valid partition, not finding a valid
   * FAT file system or an I/O error.
   */
  bool init(Sd2Card* dev) { return init(dev, 1) ? true : init(dev, 0);}
  bool init(Sd2Card* dev, uint8_t part);

  // inline functions that return volume info
  /** \return The volume's cluster size in blocks. */
  uint8_t blocksPerCluster() const {return blocksPerCluster_;}
  /** \return The number of blocks in one FAT. */
  uint32_t blocksPerFat()  const {return blocksPerFat_;}
  /** \return The total number of clusters in the volume. */
  uint32_t clusterCount() const {return clusterCount_;}
  /** \return The shift count required to multiply by blocksPerCluster. */
  uint8_t clusterSizeShift() const {return clusterSizeShift_;}
  /** \return The logical block number for the start of file data. */
  uint32_t dataStartBlock() const {return dataStartBlock_;}
  /** \return The number of FAT structures on the volume. */
  uint8_t fatCount() const {return fatCount_;}
  /** \return The logical block number for the start of the first FAT. */
  uint32_t fatStartBlock() const {return fatStartBlock_;}
  /** \return The FAT type of the volume. Values are 12, 16 or 32. */
  uint8_t fatType() const {return fatType_;}
  int32_t freeClusterCount();
  /** \return The number of entries in the root directory for FAT16 volumes. */
  uint32_t rootDirEntryCount() const {return rootDirEntryCount_;}
  /** \return The logical block number for the start of the root directory
       on FAT16 volumes or the first cluster number on FAT32 volumes. */
  uint32_t rootDirStart() const {return rootDirStart_;}
  /** Sd2Card object for this volume
   * \return pointer to Sd2Card object.
   */
  Sd2Card* sdCard() {return sdCard_;}
  /** Debug access to FAT table
   *
   * \param[in] n cluster number.
   * \param[out] v value of entry
   * \return true for success or false for failure
   */
  bool dbgFat(uint32_t n, uint32_t* v) {return fatGet(n, v);}
//------------------------------------------------------------------------------
 private:
  // Allow SdBaseFile access to SdVolume private data.
  friend class SdBaseFile;

  // value for dirty argument in cacheRawBlock to indicate read from cache
  static bool const CACHE_FOR_READ = false;
  // value for dirty argument in cacheRawBlock to indicate write to cache
  static bool const CACHE_FOR_WRITE = true;

#if USE_MULTIPLE_CARDS
  cache_t cacheBuffer_;        // 512 byte cache for device blocks
  uint32_t cacheBlockNumber_;  // Logical number of block in the cache
  Sd2Card* sdCard_;            // Sd2Card object for cache
  bool cacheDirty_;            // cacheFlush() will write block if true
  uint32_t cacheMirrorBlock_;  // block number for mirror FAT
#else  // USE_MULTIPLE_CARDS
  static cache_t cacheBuffer_;        // 512 byte cache for device blocks
  static uint32_t cacheBlockNumber_;  // Logical number of block in the cache
  static Sd2Card* sdCard_;            // Sd2Card object for cache
  static bool cacheDirty_;            // cacheFlush() will write block if true
  static uint32_t cacheMirrorBlock_;  // block number for mirror FAT
#endif  // USE_MULTIPLE_CARDS
  uint32_t allocSearchStart_;   // start cluster for alloc search
  uint8_t blocksPerCluster_;    // cluster size in blocks
  uint32_t blocksPerFat_;       // FAT size in blocks
  uint32_t clusterCount_;       // clusters in one FAT
  uint8_t clusterSizeShift_;    // shift to convert cluster count to block count
  uint32_t dataStartBlock_;     // first data block number
  uint8_t fatCount_;            // number of FATs on volume
  uint32_t fatStartBlock_;      // start block for first FAT
  uint8_t fatType_;             // volume type (12, 16, OR 32)
  uint16_t rootDirEntryCount_;  // number of entries in FAT16 root dir
  uint32_t rootDirStart_;       // root start block for FAT16, cluster for FAT32
  //----------------------------------------------------------------------------
  bool allocContiguous(uint32_t count, uint32_t* curCluster);
  uint8_t blockOfCluster(uint32_t position) const {
          return (position >> 9) & (blocksPerCluster_ - 1);}
  uint32_t clusterStartBlock(uint32_t cluster) const {
           return dataStartBlock_ + ((cluster - 2) << clusterSizeShift_);}
  uint32_t blockNumber(uint32_t cluster, uint32_t position) const {
           return clusterStartBlock(cluster) + blockOfCluster(position);}
  cache_t *cache() {return &cacheBuffer_;}
  uint32_t cacheBlockNumber() {return cacheBlockNumber_;}
#if USE_MULTIPLE_CARDS
  bool cacheFlush();
  bool cacheRawBlock(uint32_t blockNumber, bool dirty);
#else  // USE_MULTIPLE_CARDS
  static bool cacheFlush();
  static bool cacheRawBlock(uint32_t blockNumber, bool dirty);
#endif  // USE_MULTIPLE_CARDS
  // used by SdBaseFile write to assign cache to SD location
  void cacheSetBlockNumber(uint32_t blockNumber, bool dirty) {
    cacheDirty_ = dirty;
    cacheBlockNumber_  = blockNumber;
  }
  void cacheSetDirty() {cacheDirty_ |= CACHE_FOR_WRITE;}
  bool chainSize(uint32_t beginCluster, uint32_t* size);
  bool fatGet(uint32_t cluster, uint32_t* value);
  bool fatPut(uint32_t cluster, uint32_t value);
  bool fatPutEOC(uint32_t cluster) {
    return fatPut(cluster, 0x0FFFFFFF);
  }
  bool freeChain(uint32_t cluster);
  bool isEOC(uint32_t cluster) const {
    if (FAT12_SUPPORT && fatType_ == 12) return  cluster >= FAT12EOC_MIN;
    if (fatType_ == 16) return cluster >= FAT16EOC_MIN;
    return  cluster >= FAT32EOC_MIN;
  }
  bool readBlock(uint32_t block, uint8_t* dst) {
    return sdCard_->readBlock(block, dst);}
  bool writeBlock(uint32_t block, const uint8_t* dst) {
    return sdCard_->writeBlock(block, dst);
  }
//------------------------------------------------------------------------------
  // Deprecated functions  - suppress cpplint warnings with NOLINT comment
#if ALLOW_DEPRECATED_FUNCTIONS && !defined(DOXYGEN)
 public:
  /** \deprecated Use: bool SdVolume::init(Sd2Card* dev);
   * \param[in] dev The SD card where the volume is located.
   * \return true for success or false for failure.
   */
  bool init(Sd2Card& dev) {return init(&dev);}  // NOLINT
  /** \deprecated Use: bool SdVolume::init(Sd2Card* dev, uint8_t vol);
   * \param[in] dev The SD card where the volume is located.
   * \param[in] part The partition to be used.
   * \return true for success or false for failure.
   */
  bool init(Sd2Card& dev, uint8_t part) {  // NOLINT
    return init(&dev, part);
  }
#endif  // ALLOW_DEPRECATED_FUNCTIONS
};
#endif  // SdVolume