FATFileSystem.cpp

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2012 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 #include "mbed.h"
00023 
00024 #include "ffconf.h"
00025 #include "mbed_debug.h"
00026 
00027 #include "FATFileSystem.h"
00028 #include "FATFileHandle.h"
00029 #include "FATDirHandle.h"
00030 #include "critical.h"
00031 
00032 DWORD get_fattime(void) {
00033     time_t rawtime;
00034     time(&rawtime);
00035     struct tm *ptm = localtime(&rawtime);
00036     return (DWORD)(ptm->tm_year - 80) << 25
00037          | (DWORD)(ptm->tm_mon + 1  ) << 21
00038          | (DWORD)(ptm->tm_mday     ) << 16
00039          | (DWORD)(ptm->tm_hour     ) << 11
00040          | (DWORD)(ptm->tm_min      ) << 5
00041          | (DWORD)(ptm->tm_sec/2    );
00042 }
00043 
00044 FATFileSystem *FATFileSystem::_ffs[_VOLUMES] = {0};
00045 static PlatformMutex * mutex = NULL;
00046 
00047 PlatformMutex * get_fat_mutex() {
00048     PlatformMutex * new_mutex = new PlatformMutex;
00049 
00050     core_util_critical_section_enter();
00051     if (NULL == mutex) {
00052         mutex = new_mutex;
00053     }
00054     core_util_critical_section_exit();
00055 
00056     if (mutex != new_mutex) {
00057         delete new_mutex;
00058     }
00059     return mutex;
00060 }
00061 
00062 FATFileSystem::FATFileSystem(const char* n) : FileSystemLike(n), _mutex(get_fat_mutex()) {
00063     lock();
00064     debug_if(FFS_DBG, "FATFileSystem(%s)\n", n);
00065     for(int i=0; i<_VOLUMES; i++) {
00066         if(_ffs[i] == 0) {
00067             _ffs[i] = this;
00068             _fsid[0] = '0' + i;
00069             _fsid[1] = '\0';
00070             debug_if(FFS_DBG, "Mounting [%s] on ffs drive [%s]\n", getName(), _fsid);
00071             f_mount(&_fs, _fsid, 0);
00072             unlock();
00073             return;
00074         }
00075     }
00076     error("Couldn't create %s in FATFileSystem::FATFileSystem\n", n);
00077     unlock();
00078 }
00079 
00080 FATFileSystem::~FATFileSystem() {
00081     lock();
00082     for (int i=0; i<_VOLUMES; i++) {
00083         if (_ffs[i] == this) {
00084             _ffs[i] = 0;
00085             f_mount(NULL, _fsid, 0);
00086         }
00087     }
00088     unlock();
00089 }
00090 
00091 FileHandle *FATFileSystem::open(const char* name, int flags) {
00092     lock();
00093     debug_if(FFS_DBG, "open(%s) on filesystem [%s], drv [%s]\n", name, getName(), _fsid);
00094     char n[64];
00095     sprintf(n, "%s:/%s", _fsid, name);
00096 
00097     /* POSIX flags -> FatFS open mode */
00098     BYTE openmode;
00099     if (flags & O_RDWR) {
00100         openmode = FA_READ|FA_WRITE;
00101     } else if(flags & O_WRONLY) {
00102         openmode = FA_WRITE;
00103     } else {
00104         openmode = FA_READ;
00105     }
00106     if(flags & O_CREAT) {
00107         if(flags & O_TRUNC) {
00108             openmode |= FA_CREATE_ALWAYS;
00109         } else {
00110             openmode |= FA_OPEN_ALWAYS;
00111         }
00112     }
00113 
00114     FIL fh;
00115     FRESULT res = f_open(&fh, n, openmode);
00116     if (res) {
00117         debug_if(FFS_DBG, "f_open('w') failed: %d\n", res);
00118         unlock();
00119         return NULL;
00120     }
00121     if (flags & O_APPEND) {
00122         f_lseek(&fh, fh.fsize);
00123     }
00124     FATFileHandle * handle = new FATFileHandle(fh, _mutex);
00125     unlock();
00126     return handle;
00127 }
00128 
00129 int FATFileSystem::remove(const char *filename) {
00130     lock();
00131     FRESULT res = f_unlink(filename);
00132     if (res) {
00133         debug_if(FFS_DBG, "f_unlink() failed: %d\n", res);
00134         unlock();
00135         return -1;
00136     }
00137     unlock();
00138     return 0;
00139 }
00140 
00141 int FATFileSystem::rename(const char *oldname, const char *newname) {
00142     lock();
00143     FRESULT res = f_rename(oldname, newname);
00144     if (res) {
00145         debug_if(FFS_DBG, "f_rename() failed: %d\n", res);
00146         unlock();
00147         return -1;
00148     }
00149     unlock();
00150     return 0;
00151 }
00152 
00153 int FATFileSystem::format() {
00154     lock();
00155     FRESULT res = f_mkfs(_fsid, 0, 512); // Logical drive number, Partitioning rule, Allocation unit size (bytes per cluster)
00156     if (res) {
00157         debug_if(FFS_DBG, "f_mkfs() failed: %d\n", res);
00158         unlock();
00159         return -1;
00160     }
00161     unlock();
00162     return 0;
00163 }
00164 
00165 DirHandle *FATFileSystem::opendir(const char *name) {
00166     lock();
00167     FATFS_DIR dir;
00168     FRESULT res = f_opendir(&dir, name);
00169     if (res != 0) {
00170         unlock();
00171         return NULL;
00172     }
00173     FATDirHandle *handle = new FATDirHandle(dir, _mutex);
00174     unlock();
00175     return handle;
00176 }
00177 
00178 int FATFileSystem::mkdir(const char *name, mode_t mode) {
00179     lock();
00180     FRESULT res = f_mkdir(name);
00181     unlock();
00182     return res == 0 ? 0 : -1;
00183 }
00184 
00185 int FATFileSystem::mount() {
00186     lock();
00187     FRESULT res = f_mount(&_fs, _fsid, 1);
00188     unlock();
00189     return res == 0 ? 0 : -1;
00190 }
00191 
00192 int FATFileSystem::unmount() {
00193     lock();
00194     if (disk_sync()) {
00195         unlock();
00196         return -1;
00197     }
00198     FRESULT res = f_mount(NULL, _fsid, 0);
00199     unlock();
00200     return res == 0 ? 0 : -1;
00201 }
00202 
00203 void FATFileSystem::lock() {
00204     _mutex->lock();
00205 }
00206 
00207 void FATFileSystem::unlock() {
00208     _mutex->unlock();
00209 }