FatFS: mutex protection, ChibiOS glue layer

firmware/ext/FatFS/fatfs.mk

@@ -1,7 +1,8 @@
 # FATFS files.
 FATFSSRC = ${CHIBIOS}/os/various/fatfs_bindings/fatfs_diskio.c \
-           ${CHIBIOS}/os/various/fatfs_bindings/fatfs_syscall.c \
+           ${PROJECT_DIR}/ext/FatFS/ffsystem.c \
            ${PROJECT_DIR}/ext/FatFS/ff.c \
            ${PROJECT_DIR}/ext/FatFS/ffunicode.c
 
+
 FATFSINC = ${PROJECT_DIR}/ext

firmware/ext/FatFS/ffconf.h

@@ -280,7 +280,7 @@
 /      lock control is independent of re-entrancy. */
 
 
-#define FF_FS_REENTRANT	0
+#define FF_FS_REENTRANT	1
 #define FF_FS_TIMEOUT	TIME_MS2I(1000)
 #define FF_SYNC_t         semaphore_t*
 /* The option FF_FS_REENTRANT switches the re-entrancy (thread safe) of the FatFs

firmware/ext/FatFS/ffsystem.c

@@ -0,0 +1,111 @@
+/*------------------------------------------------------------------------*/
+/* A Sample Code of User Provided OS Dependent Functions for FatFs        */
+/*------------------------------------------------------------------------*/
+
+#include "hal.h"
+#include "ff.h"
+
+
+#if FF_USE_LFN == 3	/* Use dynamic memory allocation */
+
+/*------------------------------------------------------------------------*/
+/* Allocate/Free a Memory Block                                           */
+/*------------------------------------------------------------------------*/
+
+#include <stdlib.h>		/* with POSIX API */
+
+
+void* ff_memalloc (	/* Returns pointer to the allocated memory block (null if not enough core) */
+	UINT msize		/* Number of bytes to allocate */
+)
+{
+	return malloc((size_t)msize);	/* Allocate a new memory block */
+}
+
+
+void ff_memfree (
+	void* mblock	/* Pointer to the memory block to free (no effect if null) */
+)
+{
+	free(mblock);	/* Free the memory block */
+}
+
+#endif
+
+
+
+
+#if FF_FS_REENTRANT	/* Mutal exclusion */
+/*------------------------------------------------------------------------*/
+/* Definitions of Mutex                                                   */
+/*------------------------------------------------------------------------*/
+static semaphore_t ff_sem[FF_VOLUMES + 1];
+
+/*------------------------------------------------------------------------*/
+/* Create a Mutex                                                         */
+/*------------------------------------------------------------------------*/
+/* This function is called in f_mount function to create a new mutex
+/  or semaphore for the volume. When a 0 is returned, the f_mount function
+/  fails with FR_INT_ERR.
+*/
+
+int ff_mutex_create (	/* Returns 1:Function succeeded or 0:Could not create the mutex */
+	int vol				/* Mutex ID: Volume mutex (0 to FF_VOLUMES - 1) or system mutex (FF_VOLUMES) */
+)
+{
+	semaphore_t *sobj = &ff_sem[vol];
+	chSemObjectInit(sobj, 1);
+	return 1;
+}
+
+
+/*------------------------------------------------------------------------*/
+/* Delete a Mutex                                                         */
+/*------------------------------------------------------------------------*/
+/* This function is called in f_mount function to delete a mutex or
+/  semaphore of the volume created with ff_mutex_create function.
+*/
+
+void ff_mutex_delete (	/* Returns 1:Function succeeded or 0:Could not delete due to an error */
+	int vol				/* Mutex ID: Volume mutex (0 to FF_VOLUMES - 1) or system mutex (FF_VOLUMES) */
+)
+{
+	semaphore_t *sobj = &ff_sem[vol];
+	chSemReset(sobj, 0);
+}
+
+
+/*------------------------------------------------------------------------*/
+/* Request a Grant to Access the Volume                                   */
+/*------------------------------------------------------------------------*/
+/* This function is called on enter file functions to lock the volume.
+/  When a 0 is returned, the file function fails with FR_TIMEOUT.
+*/
+
+int ff_mutex_take (	/* Returns 1:Succeeded or 0:Timeout */
+	int vol			/* Mutex ID: Volume mutex (0 to FF_VOLUMES - 1) or system mutex (FF_VOLUMES) */
+)
+{
+	semaphore_t *sobj = &ff_sem[vol];
+	msg_t msg = chSemWaitTimeout(sobj, (systime_t)FF_FS_TIMEOUT);
+	return msg == MSG_OK;
+}
+
+
+
+/*------------------------------------------------------------------------*/
+/* Release a Grant to Access the Volume                                   */
+/*------------------------------------------------------------------------*/
+/* This function is called on leave file functions to unlock the volume.
+*/
+
+void ff_mutex_give (
+	int vol			/* Mutex ID: Volume mutex (0 to FF_VOLUMES - 1) or system mutex (FF_VOLUMES) */
+)
+{
+	semaphore_t *sobj = &ff_sem[vol];
+	chSemSignal(sobj);
+}
+
+#endif	/* FF_FS_REENTRANT */
+