fs: Adds the glue layer for the Fat FS module

Adds the glue layer to interface the Fat FS module with Zephyr
file system API.

Origin: Original
Jira: ZEP-228 ZEP-483
Change-Id: I878fdad8ecaf46992d6163e24a9b0b633f49154f
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>

fs/Makefile

@@ -1 +1,2 @@
 obj-$(CONFIG_FS_FAT_RAM_DISK) += fat_ram_diskio.o
+obj-$(CONFIG_FILE_SYSTEM_FAT) += fat_fs.o

fs/fat_fs.c

@@ -0,0 +1,235 @@
+/*
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * 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 <stdio.h>
+#include <string.h>
+#include <stdint.h>
+#include <errno.h>
+#include <init.h>
+#include <ff.h>
+#include <fs.h>
+#include <misc/__assert.h>
+
+static FATFS fat_fs;	/* FatFs work area */
+
+static int translate_error(int error)
+{
+	switch (error) {
+	case FR_OK:
+		return 0;
+	case FR_NO_FILE:
+	case FR_NO_PATH:
+	case FR_INVALID_NAME:
+		return -ENOENT;
+	case FR_DENIED:
+		return -EACCES;
+	case FR_EXIST:
+		return -EEXIST;
+	case FR_INVALID_OBJECT:
+		return -EBADF;
+	case FR_WRITE_PROTECTED:
+		return -EROFS;
+	case FR_INVALID_DRIVE:
+	case FR_NOT_ENABLED:
+	case FR_NO_FILESYSTEM:
+		return -ENODEV;
+	case FR_NOT_ENOUGH_CORE:
+		return -ENOMEM;
+	case FR_TOO_MANY_OPEN_FILES:
+		return -EMFILE;
+	case FR_INVALID_PARAMETER:
+		return -EINVAL;
+	case FR_LOCKED:
+	case FR_TIMEOUT:
+	case FR_MKFS_ABORTED:
+	case FR_DISK_ERR:
+	case FR_INT_ERR:
+	case FR_NOT_READY:
+		return -EIO;
+	}
+
+	return -EIO;
+}
+
+int fs_open(ZFILE *zfp, const char *file_name)
+{
+	FRESULT res;
+	uint8_t fs_mode;
+
+	fs_mode = FA_READ | FA_WRITE | FA_OPEN_ALWAYS;
+
+	res = f_open(&zfp->fp, file_name, fs_mode);
+
+	return translate_error(res);
+}
+
+int fs_close(ZFILE *zfp)
+{
+	FRESULT res;
+
+	res = f_close(&zfp->fp);
+
+	return translate_error(res);
+}
+
+int fs_unlink(const char *path)
+{
+	FRESULT res;
+
+	res = f_unlink(path);
+
+	return translate_error(res);
+}
+
+ssize_t fs_read(ZFILE *zfp, void *ptr, size_t size)
+{
+	FRESULT res;
+	unsigned int br;
+
+	res = f_read(&zfp->fp, ptr, size, &br);
+	if (res != FR_OK) {
+		return translate_error(res);
+	}
+
+	return br;
+}
+
+ssize_t fs_write(ZFILE *zfp, const void *ptr, size_t size)
+{
+	FRESULT res;
+	unsigned int bw;
+
+	res = f_write(&zfp->fp, ptr, size, &bw);
+	if (res != FR_OK) {
+		return translate_error(res);
+	}
+
+	return bw;
+}
+
+int fs_seek(ZFILE *zfp, off_t offset, int whence)
+{
+	FRESULT res = FR_OK;
+	off_t pos;
+
+	switch (whence) {
+	case SEEK_SET:
+		pos = offset;
+		break;
+	case SEEK_CUR:
+		pos = f_tell(&zfp->fp) + offset;
+		break;
+	case SEEK_END:
+		pos = f_size(&zfp->fp) + offset;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if ((pos < 0) || (pos > f_size(&zfp->fp))) {
+		return -EINVAL;
+	}
+
+	res = f_lseek(&zfp->fp, pos);
+
+	return translate_error(res);
+}
+
+int fs_mkdir(const char *path)
+{
+	FRESULT res;
+
+	res = f_mkdir(path);
+
+	return translate_error(res);
+}
+
+int fs_opendir(ZDIR *zdp, const char *path)
+{
+	FRESULT res;
+
+	res = f_opendir(&zdp->dp, path);
+
+	return translate_error(res);
+}
+
+int fs_readdir(ZDIR *zdp, struct zfs_dirent *entry)
+{
+	FRESULT res;
+	FILINFO fno;
+
+	res = f_readdir(&zdp->dp, &fno);
+	if (res == FR_OK) {
+		entry->type = ((fno.fattrib & AM_DIR) ?
+			       DIR_ENTRY_DIR : DIR_ENTRY_FILE);
+		strcpy(entry->name, fno.fname);
+		entry->size = fno.fsize;
+	}
+
+	return translate_error(res);
+}
+
+int fs_closedir(ZDIR *zdp)
+{
+	FRESULT res;
+
+	res = f_closedir(&zdp->dp);
+
+	return translate_error(res);
+}
+
+int fs_stat(const char *path, struct zfs_dirent *entry)
+{
+	FRESULT res;
+	FILINFO fno;
+
+	res = f_stat(path, &fno);
+	if (res == FR_OK) {
+		entry->type = ((fno.fattrib & AM_DIR) ?
+			       DIR_ENTRY_DIR : DIR_ENTRY_FILE);
+		strcpy(entry->name, fno.fname);
+		entry->size = fno.fsize;
+	}
+
+	return translate_error(res);
+}
+
+static int fs_init(struct device *dev)
+{
+	FRESULT res;
+
+	ARG_UNUSED(dev);
+
+	res = f_mount(&fat_fs, "", 1);
+
+	/* If no file system found then create one */
+	if (res == FR_NO_FILESYSTEM) {
+		uint8_t work[_MAX_SS];
+
+		res = f_mkfs("", (FM_FAT | FM_SFD), _MAX_SS,
+			     work, sizeof(work));
+
+		if (res == FR_OK) {
+			res = f_mount(&fat_fs, "", 1);
+		}
+	}
+
+	__ASSERT((res == FR_OK), "FS init failed (%d)", translate_error(res));
+
+	return translate_error(res);
+}
+
+SYS_INIT(fs_init, APPLICATION, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);

include/fs/fat_fs.h

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * 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 _FAT_FS_H_
+#define _FAT_FS_H_
+
+#include <sys/types.h>
+#include <ff.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+ZFILE_DEFINE(FIL fp);
+ZDIR_DEFINE(DIR dp);
+
+#define MAX_FILE_NAME 12 /* Uses 8.3 SFN */
+
+static inline off_t fs_tell(struct _zfile_object *zfp)
+{
+	return f_tell(&zfp->fp);
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _FAT_FS_H_ */