/* mbed Microcontroller Library
* Copyright (c) 2018-2020 ARM Limited
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef MBED_BUFFERED_BLOCK_DEVICE_H
#define MBED_BUFFERED_BLOCK_DEVICE_H
#include "BlockDevice.h"
namespace mbed {
/** \addtogroup storage-blockdevice */
/** @{*/
/** Block device for allowing minimal read and program sizes (of 1) for the underlying BD,
* using a buffer on the heap.
*/
class BufferedBlockDevice : public BlockDevice {
public:
/** Lifetime of a memory-buffered block device wrapping an underlying block device
*
* @param bd Block device to back the BufferedBlockDevice
*/
BufferedBlockDevice(BlockDevice *bd);
/** Lifetime of the memory-buffered block device
*/
virtual ~BufferedBlockDevice();
/** Initialize a buffered-memory block device and its underlying block device
*
* @return 0 on success or a negative error code on failure
*/
virtual int init();
/** Deinitialize the buffered-memory block device and its underlying block device
*
* @return 0 on success or a negative error code on failure
*/
virtual int deinit();
/** Ensure that data on the underlying storage block device is in sync with the
* memory-buffered block device
*
* @return 0 on success or a negative error code on failure
*/
virtual int sync();
/** Read blocks from the memory-buffered block device
*
* @param buffer Buffer to read blocks into
* @param addr Address of block to begin reading from
* @param size Size to read in bytes, must be a multiple of read block size
* @return 0 on success, negative error code on failure
*/
virtual int read(void *buffer, bd_addr_t addr, bd_size_t size);
/** Program data to the memory-buffered block device
*
* The write address blocks must be erased prior to being programmed.
*
* @param buffer Buffer of data to write to blocks
* @param addr Address of block to begin writing to
* @param size Size to write in bytes, must be a multiple of program block size
* @return 0 on success, negative error code on failure
*/
virtual int program(const void *buffer, bd_addr_t addr, bd_size_t size);
/** Erase blocks from the memory-buffered block device
*
* The state of an erased block is undefined until it has been programmed,
* unless get_erase_value returns a non-negative byte value.
*
* @param addr Address of block to begin erasing
* @param size Size to erase in bytes, must be a multiple of erase block size
* @return 0 on success, negative error code on failure
*/
virtual int erase(bd_addr_t addr, bd_size_t size);
/** Mark blocks as no longer in use
*
* This function provides a hint to the underlying block device that a region of blocks
* is no longer in use and may be erased without side effects. Erase must still be called
* before programming, but trimming allows flash-translation-layers to schedule erases when
* the device is not busy.
*
* @param addr Address of block to mark as unused
* @param size Size to mark as unused in bytes, must be a multiple of erase block size
* @return 0 on success, negative error code on failure
*/
virtual int trim(bd_addr_t addr, bd_size_t size);
/** Get the size of a readable block
*
* @return Size of a readable block in bytes
*/
virtual bd_size_t get_read_size() const;
/** Get the size of a programmable block
*
* @return Size of a programmable block in bytes
* @note Must be a multiple of the read size
*/
virtual bd_size_t get_program_size() const;
/** Get the size of an erasable block
*
* @return Size of an erasable block in bytes
* @note Must be a multiple of the program size
*/
virtual bd_size_t get_erase_size() const;
/** Get the size of an erasable block of a given address
*
* @param addr Address within the erasable block
* @return Size of an erasable block in bytes
* @note Must be a multiple of the program size
*/
virtual bd_size_t get_erase_size(bd_addr_t addr) const;
/** Get the value of storage data after being erased
*
* If get_erase_value returns a non-negative byte value, the underlying
* storage is set to that value when erased, and storage containing
* that value can be programmed without another erase.
*
* @return The value of storage when erased, or -1 if you can't
* rely on the value of erased storage
*/
virtual int get_erase_value() const;
/** Get the total size of the underlying device
*
* @return Size of the underlying device in bytes
*/
virtual bd_size_t size() const;
/** Get the underlying BlockDevice class type
*
* @return A string representing the underlying BlockDevice class type
*/
virtual const char *get_type() const;
protected:
BlockDevice *_bd;
bd_size_t _bd_program_size;
bd_size_t _bd_read_size;
bd_size_t _bd_size;
bd_size_t _write_cache_addr;
bool _write_cache_valid;
uint8_t *_write_cache;
uint8_t *_read_buf;
uint32_t _init_ref_count;
bool _is_initialized;
#if !(DOXYGEN_ONLY)
/** Flush data in cache
*
* @return 0 on success or a negative error code on failure
*/
int flush();
/** Invalidate write cache
*
* @return none
*/
void invalidate_write_cache();
#endif //#if !(DOXYGEN_ONLY)
};
/** @}*/
} // namespace mbed
// Added "using" for backwards compatibility
#ifndef MBED_NO_GLOBAL_USING_DIRECTIVE
using mbed::BufferedBlockDevice;
#endif
#endif
