ChainingBlockDevice.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2017 ARM Limited
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00020  * SOFTWARE.
00021  */
00022 #ifndef MBED_CHAINING_BLOCK_DEVICE_H
00023 #define MBED_CHAINING_BLOCK_DEVICE_H
00024 
00025 #include "BlockDevice.h"
00026 #include "mbed.h"
00027 
00028 
00029 /** Block device for chaining multiple block devices
00030  *  with the similar block sizes at sequential addresses
00031  *
00032  *  @code
00033  *  #include "mbed.h"
00034  *  #include "HeapBlockDevice.h"
00035  *  #include "ChainingBlockDevice.h"
00036  *
00037  *  // Create two smaller block devices with
00038  *  // 64 and 32 blocks of size 512 bytes
00039  *  HeapBlockDevice mem1(64*512, 512);
00040  *  HeapBlockDevice mem2(32*512, 512);
00041  *
00042  *  // Create a block device backed by mem1 and mem2
00043  *  // contains 96 blocks of size 512 bytes
00044  *  BlockDevice *bds[] = {&mem1, &mem2};
00045  *  ChainingBlockDevice chainmem(bds);
00046  */
00047 class ChainingBlockDevice : public BlockDevice
00048 {
00049 public:
00050     /** Lifetime of the memory block device
00051      *
00052      *  @param bds      Array of block devices to chain with sequential block addresses
00053      *  @param count    Number of block devices to chain
00054      *  @note All block devices must have the same block size
00055      */
00056     ChainingBlockDevice(BlockDevice **bds, size_t bd_count);
00057 
00058     /** Lifetime of the memory block device
00059      *
00060      *  @param bds      Array of block devices to chain with sequential block addresses
00061      *  @note All block devices must have the same block size
00062      */
00063     template <size_t Size>
00064     ChainingBlockDevice(BlockDevice *(&bds)[Size])
00065         : _bds(bds), _bd_count(sizeof(bds) / sizeof(bds[0]))
00066         , _read_size(0), _program_size(0), _erase_size(0), _size(0)
00067     {
00068     }
00069 
00070     /** Lifetime of the memory block device
00071      *
00072      *  @param bds      Array of block devices to chain with sequential block addresses
00073      *  @note All block devices must have the same block size
00074      */
00075     virtual ~ChainingBlockDevice() {}
00076 
00077     /** Initialize a block device
00078      *
00079      *  @return         0 on success or a negative error code on failure
00080      */
00081     virtual int init();
00082 
00083     /** Deinitialize a block device
00084      *
00085      *  @return         0 on success or a negative error code on failure
00086      */
00087     virtual int deinit();
00088 
00089     /** Read blocks from a block device
00090      *
00091      *  @param buffer   Buffer to write blocks to
00092      *  @param addr     Address of block to begin reading from
00093      *  @param size     Size to read in bytes, must be a multiple of read block size
00094      *  @return         0 on success, negative error code on failure
00095      */
00096     virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
00097 
00098     /** Program blocks to a block device
00099      *
00100      *  The blocks must have been erased prior to being programmed
00101      *
00102      *  @param buffer   Buffer of data to write to blocks
00103      *  @param addr     Address of block to begin writing to
00104      *  @param size     Size to write in bytes, must be a multiple of program block size
00105      *  @return         0 on success, negative error code on failure
00106      */
00107     virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
00108 
00109     /** Erase blocks on a block device
00110      *
00111      *  The state of an erased block is undefined until it has been programmed
00112      *
00113      *  @param addr     Address of block to begin erasing
00114      *  @param size     Size to erase in bytes, must be a multiple of erase block size
00115      *  @return         0 on success, negative error code on failure
00116      */
00117     virtual int erase(bd_addr_t addr, bd_size_t size);
00118 
00119     /** Get the size of a readable block
00120      *
00121      *  @return         Size of a readable block in bytes
00122      */
00123     virtual bd_size_t get_read_size() const;
00124 
00125     /** Get the size of a programable block
00126      *
00127      *  @return         Size of a programable block in bytes
00128      *  @note Must be a multiple of the read size
00129      */
00130     virtual bd_size_t get_program_size() const;
00131 
00132     /** Get the size of a eraseable block
00133      *
00134      *  @return         Size of a eraseable block in bytes
00135      *  @note Must be a multiple of the program size
00136      */
00137     virtual bd_size_t get_erase_size() const;
00138 
00139     /** Get the total size of the underlying device
00140      *
00141      *  @return         Size of the underlying device in bytes
00142      */
00143     virtual bd_size_t size() const;
00144 
00145 protected:
00146     BlockDevice **_bds;
00147     size_t _bd_count;
00148     bd_size_t _read_size;
00149     bd_size_t _program_size;
00150     bd_size_t _erase_size;
00151     bd_size_t _size;
00152 };
00153 
00154 
00155 #endif
00156