ExhaustibleBlockDevice.cpp

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2017 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #include "ExhaustibleBlockDevice.h"
00018 #include "mbed.h"
00019 
00020 
00021 ExhaustibleBlockDevice::ExhaustibleBlockDevice(BlockDevice *bd, uint32_t erase_cycles)
00022     : _bd(bd), _erase_array(NULL), _erase_cycles(erase_cycles)
00023 {
00024 }
00025 
00026 ExhaustibleBlockDevice::~ExhaustibleBlockDevice()
00027 {
00028     delete[] _erase_array;
00029 }
00030 
00031 int ExhaustibleBlockDevice::init()
00032 {
00033     int err = _bd->init();
00034     if (err) {
00035         return err;
00036     }
00037 
00038     if (!_erase_array) {
00039         // can only be allocated after initialization
00040         _erase_array = new uint32_t[_bd->size() / _bd->get_erase_size()];
00041         for (size_t i = 0; i < _bd->size() / _bd->get_erase_size(); i++) {
00042             _erase_array[i] = _erase_cycles;
00043         }
00044     }
00045 
00046     return 0;
00047 }
00048 
00049 int ExhaustibleBlockDevice::deinit()
00050 {
00051     // _erase_array is lazily cleaned up in destructor to allow
00052     // data to live across de/reinitialization
00053     return _bd->deinit();
00054 }
00055 
00056 int ExhaustibleBlockDevice::read(void *buffer, bd_addr_t addr, bd_size_t size)
00057 {
00058     return _bd->read(buffer, addr, size);
00059 }
00060 
00061 int ExhaustibleBlockDevice::program(const void *buffer, bd_addr_t addr, bd_size_t size)
00062 {
00063     MBED_ASSERT(is_valid_program(addr, size));
00064 
00065     if (_erase_array[addr / get_erase_size()] == 0) {
00066         // TODO possibly something more destructive here
00067         return 0;
00068     }
00069 
00070     return _bd->program(buffer, addr, size);
00071 }
00072 
00073 int ExhaustibleBlockDevice::erase(bd_addr_t addr, bd_size_t size)
00074 {
00075     MBED_ASSERT(is_valid_erase(addr, size));
00076 
00077     // use an erase cycle
00078     if (_erase_array[addr / get_erase_size()] > 0) {
00079         _erase_array[addr / get_erase_size()] -= 1;
00080     }
00081 
00082     if (_erase_array[addr / get_erase_size()] == 0) {
00083         // TODO possibly something more destructive here
00084         return 0;
00085     }
00086 
00087     return _bd->erase(addr, size);
00088 }
00089 
00090 bd_size_t ExhaustibleBlockDevice::get_read_size() const
00091 {
00092     return _bd->get_read_size();
00093 }
00094 
00095 bd_size_t ExhaustibleBlockDevice::get_program_size() const
00096 {
00097     return _bd->get_program_size();
00098 }
00099 
00100 bd_size_t ExhaustibleBlockDevice::get_erase_size() const
00101 {
00102     return _bd->get_erase_size();
00103 }
00104 
00105 bd_size_t ExhaustibleBlockDevice::size() const
00106 {
00107     return _bd->size();
00108 }