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 "platform/mbed_assert.h"
00027 #include <stdlib.h>
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  *  @endcode
00047  */
00048 class ChainingBlockDevice : public BlockDevice {
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 bd_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),  _init_ref_count(0)
00067     {
00068     }
00069 
00070     /** Lifetime of the memory block device
00071      *
00072      */
00073     virtual ~ChainingBlockDevice() {}
00074 
00075     /** Initialize a block device
00076      *
00077      *  @return         0 on success or a negative error code on failure
00078      */
00079     virtual int init();
00080 
00081     /** Deinitialize a block device
00082      *
00083      *  @return         0 on success or a negative error code on failure
00084      */
00085     virtual int deinit();
00086 
00087     /** Ensure data on storage is in sync with the driver
00088      *
00089      *  @return         0 on success or a negative error code on failure
00090      */
00091     virtual int sync();
00092 
00093     /** Read blocks from a block device
00094      *
00095      *  @param buffer   Buffer to write blocks to
00096      *  @param addr     Address of block to begin reading from
00097      *  @param size     Size to read in bytes, must be a multiple of read block size
00098      *  @return         0 on success, negative error code on failure
00099      */
00100     virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
00101 
00102     /** Program blocks to a block device
00103      *
00104      *  The blocks must have been erased prior to being programmed
00105      *
00106      *  @param buffer   Buffer of data to write to blocks
00107      *  @param addr     Address of block to begin writing to
00108      *  @param size     Size to write in bytes, must be a multiple of program block size
00109      *  @return         0 on success, negative error code on failure
00110      */
00111     virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
00112 
00113     /** Erase blocks on a block device
00114      *
00115      *  The state of an erased block is undefined until it has been programmed,
00116      *  unless get_erase_value returns a non-negative byte value
00117      *
00118      *  @param addr     Address of block to begin erasing
00119      *  @param size     Size to erase in bytes, must be a multiple of erase block size
00120      *  @return         0 on success, negative error code on failure
00121      */
00122     virtual int erase(bd_addr_t addr, bd_size_t size);
00123 
00124     /** Get the size of a readable block
00125      *
00126      *  @return         Size of a readable block in bytes
00127      */
00128     virtual bd_size_t get_read_size() const;
00129 
00130     /** Get the size of a programmable block
00131      *
00132      *  @return         Size of a programmable block in bytes
00133      *  @note Must be a multiple of the read size
00134      */
00135     virtual bd_size_t get_program_size() const;
00136 
00137     /** Get the size of an eraseable block
00138      *
00139      *  @return         Size of an erasable block in bytes
00140      *  @note Must be a multiple of the program size
00141      */
00142     virtual bd_size_t get_erase_size() const;
00143 
00144     /** Get the size of an erasable block given address
00145      *
00146      *  @param addr     Address within the erasable block
00147      *  @return         Size of an erasable block in bytes
00148      *  @note Must be a multiple of the program size
00149      */
00150     virtual bd_size_t get_erase_size(bd_addr_t addr) const;
00151 
00152     /** Get the value of storage when erased
00153      *
00154      *  If get_erase_value returns a non-negative byte value, the underlying
00155      *  storage is set to that value when erased, and storage containing
00156      *  that value can be programmed without another erase.
00157      *
00158      *  @return         The value of storage when erased, or -1 if you can't
00159      *                  rely on the value of erased storage
00160      */
00161     virtual int get_erase_value() const;
00162 
00163     /** Get the total size of the underlying device
00164      *
00165      *  @return         Size of the underlying device in bytes
00166      */
00167     virtual bd_size_t size() const;
00168 
00169 protected:
00170     BlockDevice **_bds;
00171     size_t _bd_count;
00172     bd_size_t _read_size;
00173     bd_size_t _program_size;
00174     bd_size_t _erase_size;
00175     bd_size_t _size;
00176     int _erase_value;
00177     uint32_t _init_ref_count;
00178     bool _is_initialized;
00179 };
00180 
00181 #endif