ReadOnlyBlockDevice.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2017-2017 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_READ_ONLY_BLOCK_DEVICE_H
00023 #define MBED_READ_ONLY_BLOCK_DEVICE_H
00024 
00025 #include "BlockDevice.h"
00026 #include "PlatformMutex.h"
00027 
00028 
00029 class ReadOnlyBlockDevice : public BlockDevice
00030 {
00031 public:
00032 
00033     /** Lifetime of the block device
00034      *
00035      * @param bd        Block device to wrap as read only
00036      */
00037     ReadOnlyBlockDevice(BlockDevice *bd);
00038     virtual ~ReadOnlyBlockDevice();
00039 
00040     /** Initialize a block device
00041      *
00042      *  @return         0 on success or a negative error code on failure
00043      */
00044     virtual int init();
00045 
00046     /** Deinitialize a block device
00047      *
00048      *  @return         0 on success or a negative error code on failure
00049      */
00050     virtual int deinit();
00051 
00052     /** Ensure data on storage is in sync with the driver
00053      *
00054      *  @return         0 on success or a negative error code on failure
00055      */
00056     virtual int sync();
00057 
00058     /** Read blocks from a block device
00059      *
00060      *  @param buffer   Buffer to read blocks into
00061      *  @param addr     Address of block to begin reading from
00062      *  @param size     Size to read in bytes, must be a multiple of read block size
00063      *  @return         0 on success, negative error code on failure
00064      */
00065     virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
00066 
00067     /** Program blocks to a block device
00068      *
00069      *  The blocks must have been erased prior to being programmed
00070      *
00071      *  @param buffer   Buffer of data to write to blocks
00072      *  @param addr     Address of block to begin writing to
00073      *  @param size     Size to write in bytes, must be a multiple of program block size
00074      *  @return         0 on success, negative error code on failure
00075      */
00076     virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
00077 
00078     /** Erase blocks on a block device
00079      *
00080      *  The state of an erased block is undefined until it has been programmed,
00081      *  unless get_erase_value returns a non-negative byte value
00082      *
00083      *  @param addr     Address of block to begin erasing
00084      *  @param size     Size to erase in bytes, must be a multiple of erase block size
00085      *  @return         0 on success, negative error code on failure
00086      */
00087     virtual int erase(bd_addr_t addr, bd_size_t size);
00088 
00089     /** Get the size of a readable block
00090      *
00091      *  @return         Size of a readable block in bytes
00092      */
00093     virtual bd_size_t get_read_size() const;
00094 
00095     /** Get the size of a programmable block
00096      *
00097      *  @return         Size of a programmable block in bytes
00098      */
00099     virtual bd_size_t get_program_size() const;
00100 
00101     /** Get the size of an erasable block
00102      *
00103      *  @return         Size of an erasable block in bytes
00104      */
00105     virtual bd_size_t get_erase_size() const;
00106 
00107     /** Get the size of an erasable block given address
00108      *
00109      *  @param addr     Address within the erasable block
00110      *  @return         Size of an erasable block in bytes
00111      *  @note Must be a multiple of the program size
00112      */
00113     virtual bd_size_t get_erase_size(bd_addr_t addr) const;
00114 
00115     /** Get the value of storage when erased
00116      *
00117      *  If get_erase_value returns a non-negative byte value, the underlying
00118      *  storage is set to that value when erased, and storage containing
00119      *  that value can be programmed without another erase.
00120      *
00121      *  @return         The value of storage when erased, or -1 if you can't
00122      *                  rely on the value of erased storage
00123      */
00124     virtual int get_erase_value() const;
00125 
00126     /** Get the total size of the underlying device
00127      *
00128      *  @return         Size of the underlying device in bytes
00129      */
00130     virtual bd_size_t size() const;
00131 
00132 private:
00133     BlockDevice *_bd;
00134 };
00135 
00136 
00137 
00138 #endif