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bd: Added prototype block device api

pull/3762/head
Christopher Haster 2017-01-20 12:33:58 -06:00 committed by Simon Hughes
parent 67165e292c
commit 99698379ef
2 changed files with 261 additions and 0 deletions
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75
features/filesystem/bd/BlockDevice.cpp Normal file
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/* mbed Microcontroller Library
* Copyright (c) 2017 ARM Limited
*
* 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.
*/
#include "BlockDevice.h"
// Writes by default perform an erase + program
bd_error_t BlockDevice::write(const void *buffer, bd_addr_t addr, bd_size_t size)
{
if (!is_valid_write(addr, size)) {
return BD_ERROR_PARAMETER;
}
bd_error_t err = erase(addr, size);
if (err) {
return err;
}
return program(buffer, addr, size);
}
bd_size_t BlockDevice::get_write_size()
{
return get_erase_size();
}
bool BlockDevice::is_valid_write(bd_addr_t addr, bd_size_t size)
{
return is_valid_erase(addr, size);
}
// Convenience functions for checking block validity
static bool is_aligned(uint64_t x, uint64_t alignment)
{
return (x / alignment) * alignment == x;
}
bool BlockDevice::is_valid_read(bd_addr_t addr, bd_size_t size)
{
return (
is_aligned(addr, get_read_size()) &&
is_aligned(size, get_read_size()) &&
addr + size <= this->size());
}
bool BlockDevice::is_valid_erase(bd_addr_t addr, bd_size_t size)
{
return (
is_aligned(addr, get_erase_size()) &&
is_aligned(size, get_erase_size()) &&
addr + size <= this->size());
}
bool BlockDevice::is_valid_program(bd_addr_t addr, bd_size_t size)
{
return (
is_aligned(addr, get_program_size()) &&
is_aligned(size, get_program_size()) &&
addr + size <= this->size());
}

186
features/filesystem/bd/BlockDevice.h Normal file
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/* mbed Microcontroller Library
* Copyright (c) 2017 ARM Limited
*
* 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_BLOCK_DEVICE_H
#define MBED_BLOCK_DEVICE_H
#include <stdint.h>
/** Enum of standard error codes
*
* @enum bd_error_t
*/
enum bd_error {
BD_ERROR_OK = 0, /*!< no error */
BD_ERROR_WOULD_BLOCK = -4001, /*!< operation would block */
BD_ERROR_UNSUPPORTED = -4002, /*!< unsupported operation */
BD_ERROR_PARAMETER = -4003, /*!< invalid parameter */
BD_ERROR_NO_INIT = -4004, /*!< uninitialized */
BD_ERROR_NO_DEVICE = -4005, /*!< device is missing or not connected */
BD_ERROR_WRITE_PROTECTED = -4006, /*!< write protected */
BD_ERROR_DEVICE_ERROR = -4007, /*!< device specific error */
};
/** Type representing either 0 or a negative error code
*/
typedef int32_t bd_error_t;
/** Type representing the address of a specific block
*/
typedef uint64_t bd_addr_t;
/** Type representing a quantity of 8-bit bytes
*/
typedef uint64_t bd_size_t;
/** A hardware device capable of writing and reading blocks
*/
class BlockDevice {
public:
/** Lifetime of a block device
*/
virtual ~BlockDevice() {};
/** Initialize a block device
*
* @return 0 on success or a negative error code on failure
*/
virtual bd_error_t init() = 0;
/** Deinitialize a block device
*
* @return 0 on success or a negative error code on failure
*/
virtual bd_error_t deinit() = 0;
/** Read blocks from a block device
*
* If a failure occurs, it is not possible to determine how many bytes succeeded
*
* @param buffer Buffer to write blocks to
* @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 bd_error_t read(void *buffer, bd_addr_t addr, bd_size_t size) = 0;
/** Write blocks to a block device
*
* A write is equivalent to an erase followed by a program
*
* If a failure occurs, it is not possible to determine how many bytes succeeded
*
* @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 write block size
* @return 0 on success, negative error code on failure
*/
virtual bd_error_t write(const void *buffer, bd_addr_t addr, bd_size_t size);
/** Program blocks to a block device
*
* The blocks must have been erased prior to being programmed
*
* If a failure occurs, it is not possible to determine how many bytes succeeded
*
* @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 bd_error_t program(const void *buffer, bd_addr_t addr, bd_size_t size) = 0;
/** Erase blocks on a block device
*
* The state of an erased block is undefined until it has been programmed
*
* @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 bd_error_t erase(bd_addr_t addr, bd_size_t size) = 0;
/** Get the size of a readable block
*
* @return Size of a readable block in bytes
*/
virtual bd_size_t get_read_size() = 0;
/** Get the size of a writeable block
*
* @return Size of a writeable block in bytes
* @note Must be a multiple of the read size, this is
* equivalent to the erase size of the device
*/
virtual bd_size_t get_write_size();
/** Get the size of a programable block
*
* @return Size of a programable block in bytes
* @note Must be a multiple of the read size
*/
virtual bd_size_t get_program_size() = 0;
/** Get the size of a eraseable block
*
* @return Size of a eraseable block in bytes
* @note Must be a multiple of the program size
*/
virtual bd_size_t get_erase_size() = 0;
/** Get the total size of the underlying device
*
* @return Size of the underlying device in bytes
*/
virtual bd_size_t size() = 0;
/** Convenience function for checking block read validity
*
* @param addr Address of block to begin reading from
* @param size Size to read in bytes
* @return True if read is valid for underlying block device
*/
bool is_valid_read(bd_addr_t addr, bd_size_t size);
/** Convenience function for checking block write validity
*
* @param addr Address of block to begin writing to
* @param size Size to write in bytes
* @return True if write is valid for underlying block device
*/
bool is_valid_write(bd_addr_t addr, bd_size_t size);
/** Convenience function for checking block program validity
*
* @param addr Address of block to begin writing to
* @param size Size to write in bytes
* @return True if program is valid for underlying block device
*/
bool is_valid_program(bd_addr_t addr, bd_size_t size);
/** Convenience function for checking block erase validity
*
* @param addr Address of block to begin erasing
* @param size Size to erase in bytes
* @return True if erase is valid for underlying block device
*/
bool is_valid_erase(bd_addr_t addr, bd_size_t size);
};
#endif