/*----------------------------------------------------------------------------/
/  FatFs - FAT file system module  R0.07c                    (C)ChaN, 2009
/-----------------------------------------------------------------------------/
/ FatFs module is an open source software to implement FAT file system to
/ small embedded systems. This is a free software and is opened for education,
/ research and commercial use under license policy of following trems.
/
/  Copyright (C) 2009, ChaN, all right reserved.
/
/ * The FatFs module is a free software and there is NO WARRANTY.
/ * No restriction on use. You can use, modify and redistribute it for
/   personal, non-profit or commercial products UNDER YOUR RESPONSIBILITY.
/ * Redistributions of source code must retain the above copyright notice.
/
/-----------------------------------------------------------------------------/
/ Feb 26,'06 R0.00  Prototype.
/
/ Apr 29,'06 R0.01  First stable version.
/
/ Jun 01,'06 R0.02  Added FAT12 support.
/                   Removed unbuffered mode.
/                   Fixed a problem on small (<32M) patition.
/ Jun 10,'06 R0.02a Added a configuration option (_FS_MINIMUM).
/
/ Sep 22,'06 R0.03  Added f_rename().
/                   Changed option _FS_MINIMUM to _FS_MINIMIZE.
/ Dec 11,'06 R0.03a Improved cluster scan algolithm to write files fast.
/                   Fixed f_mkdir() creates incorrect directory on FAT32.
/
/ Feb 04,'07 R0.04  Supported multiple drive system.
/                   Changed some interfaces for multiple drive system.
/                   Changed f_mountdrv() to f_mount().
/                   Added f_mkfs().
/ Apr 01,'07 R0.04a Supported multiple partitions on a plysical drive.
/                   Added a capability of extending file size to f_lseek().
/                   Added minimization level 3.
/                   Fixed an endian sensitive code in f_mkfs().
/ May 05,'07 R0.04b Added a configuration option _USE_NTFLAG.
/                   Added FSInfo support.
/                   Fixed DBCS name can result FR_INVALID_NAME.
/                   Fixed short seek (<= csize) collapses the file object.
/
/ Aug 25,'07 R0.05  Changed arguments of f_read(), f_write() and f_mkfs().
/                   Fixed f_mkfs() on FAT32 creates incorrect FSInfo.
/                   Fixed f_mkdir() on FAT32 creates incorrect directory.
/ Feb 03,'08 R0.05a Added f_truncate() and f_utime().
/                   Fixed off by one error at FAT sub-type determination.
/                   Fixed btr in f_read() can be mistruncated.
/                   Fixed cached sector is not flushed when create and close
/                   without write.
/
/ Apr 01,'08 R0.06  Added fputc(), fputs(), fprintf() and fgets().
/                   Improved performance of f_lseek() on moving to the same
/                   or following cluster.
/
/ Apr 01,'09 R0.07  Merged Tiny-FatFs as a buffer configuration option.
/                   Added long file name support.
/                   Added multiple code page support.
/                   Added re-entrancy for multitask operation.
/                   Added auto cluster size selection to f_mkfs().
/                   Added rewind option to f_readdir().
/                   Changed result code of critical errors.
/                   Renamed string functions to avoid name collision.
/ Apr 14,'09 R0.07a Separated out OS dependent code on reentrant cfg.
/                   Added multiple sector size support.
/ Jun 21,'09 R0.07c Fixed f_unlink() may return FR_OK on error.
/                   Fixed wrong cache control in f_lseek().
/                   Added relative path feature.
/                   Added f_chdir() and f_chdrive().
/                   Added proper case conversion to extended char.
/---------------------------------------------------------------------------*/

#include "ff.h"			/* FatFs configurations and declarations */
#include "diskio.h"		/* Declarations of low level disk I/O functions */

/*--------------------------------------------------------------------------

   Module Private Definitions

---------------------------------------------------------------------------*/

#if _FS_REENTRANT
#if _USE_LFN == 1
#error Static LFN work area must not be used in re-entrant configuration.
#endif
#define	ENTER_FF(fs)		{ if (!lock_fs(fs)) return FR_TIMEOUT; }
#define	LEAVE_FF(fs, res)	{ unlock_fs(fs, res); return res; }

#else
#define	ENTER_FF(fs)
#define LEAVE_FF(fs, res)	return res

#endif

#define	ABORT(fs, res)		{ fp->flag |= FA__ERROR; LEAVE_FF(fs, res); }

#ifndef NULL
#define	NULL	0
#endif

/* Name status flags */
#define NS_LOSS		0x01	/* Lossy conversion */
#define NS_LFN		0x02	/* Force to create LFN entry */
#define NS_LAST		0x04	/* Last segment */
#define NS_BODY		0x08	/* Lower case flag (body) */
#define NS_EXT		0x10	/* Lower case flag (ext) */
#define NS_DOT		0x20	/* Dot entry */




/*--------------------------------------------------------------------------

   Private Work Area

---------------------------------------------------------------------------*/

static
FATFS *FatFs[_DRIVES];	/* Pointer to the file system objects (logical drives) */

static
WORD Fsid;				/* File system mount ID */

#if _FS_RPATH
static
BYTE Drive;				/* Current drive */
#endif


#if _USE_LFN == 1	/* LFN with static LFN working buffer */
static
WORD LfnBuf[_MAX_LFN + 1];
#define	NAMEBUF(sp,lp)	BYTE sp[12]; WCHAR *lp = LfnBuf
#define INITBUF(dj,sp,lp)	dj.fn = sp; dj.lfn = lp

#elif _USE_LFN > 1	/* LFN with dynamic LFN working buffer */
#define	NAMEBUF(sp,lp)	BYTE sp[12]; WCHAR lbuf[_MAX_LFN + 1], *lp = lbuf
#define INITBUF(dj,sp,lp)	dj.fn = sp; dj.lfn = lp

#else				/* No LFN */
#define	NAMEBUF(sp,lp)	BYTE sp[12]
#define INITBUF(dj,sp,lp)	dj.fn = sp

#endif




/*--------------------------------------------------------------------------

   Private Functions

---------------------------------------------------------------------------*/


/*-----------------------------------------------------------------------*/
/* String functions                                                      */
/*-----------------------------------------------------------------------*/

/* Copy memory to memory */
static
void mem_cpy (void* dst, const void* src, int cnt) {
	char *d = (char*)dst;
	const char *s = (const char *)src;
	while (cnt--) *d++ = *s++;
}

/* Fill memory */
static
void mem_set (void* dst, int val, int cnt) {
	char *d = (char*)dst;
	while (cnt--) *d++ = (char)val;
}

/* Compare memory to memory */
static
int mem_cmp (const void* dst, const void* src, int cnt) {
	const char *d = (const char *)dst, *s = (const char *)src;
	int r = 0;
	while (cnt-- && (r = *d++ - *s++) == 0) ;
	return r;
}

/* Check if chr is contained in the string */
static
int chk_chr (const char* str, int chr) {
	while (*str && *str != chr) str++;
	return *str;
}



/*-----------------------------------------------------------------------*/
/* Request/Release grant to access the volume                            */
/*-----------------------------------------------------------------------*/
#if _FS_REENTRANT

static
BOOL lock_fs (
	FATFS *fs		/* File system object */
)
{
	return ff_req_grant(fs->sobj);
}


static
void unlock_fs (
	FATFS *fs,		/* File system object */
	FRESULT res		/* Result code to be returned */
)
{
	if (res != FR_NOT_ENABLED &&
		res != FR_INVALID_DRIVE &&
		res != FR_INVALID_OBJECT &&
		res != FR_TIMEOUT) {
		ff_rel_grant(fs->sobj);
	}
}
#endif



/*-----------------------------------------------------------------------*/
/* Change window offset                                                  */
/*-----------------------------------------------------------------------*/

static
FRESULT move_window (
	FATFS *fs,		/* File system object */
	DWORD sector	/* Sector number to make apperance in the fs->win[] */
)					/* Move to zero only writes back dirty window */
{
	DWORD wsect;


	wsect = fs->winsect;
	if (wsect != sector) {	/* Changed current window */
#if !_FS_READONLY
		if (fs->wflag) {	/* Write back dirty window if needed */
			if (disk_write(fs->drive, fs->win, wsect, 1) != RES_OK)
				return FR_DISK_ERR;
			fs->wflag = 0;
			if (wsect < (fs->fatbase + fs->sects_fat)) {	/* In FAT area */
				BYTE nf;
				for (nf = fs->n_fats; nf > 1; nf--) {	/* Refrect the change to all FAT copies */
					wsect += fs->sects_fat;
					disk_write(fs->drive, fs->win, wsect, 1);
				}
			}
		}
#endif
		if (sector) {
			if (disk_read(fs->drive, fs->win, sector, 1) != RES_OK)
				return FR_DISK_ERR;
			fs->winsect = sector;
		}
	}

	return FR_OK;
}




/*-----------------------------------------------------------------------*/
/* Clean-up cached data                                                  */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
static
FRESULT sync (	/* FR_OK: successful, FR_DISK_ERR: failed */
	FATFS *fs	/* File system object */
)
{
	FRESULT res;


	res = move_window(fs, 0);
	if (res == FR_OK) {
		/* Update FSInfo sector if needed */
		if (fs->fs_type == FS_FAT32 && fs->fsi_flag) {
			fs->winsect = 0;
			mem_set(fs->win, 0, 512);
			ST_WORD(fs->win+BS_55AA, 0xAA55);
			ST_DWORD(fs->win+FSI_LeadSig, 0x41615252);
			ST_DWORD(fs->win+FSI_StrucSig, 0x61417272);
			ST_DWORD(fs->win+FSI_Free_Count, fs->free_clust);
			ST_DWORD(fs->win+FSI_Nxt_Free, fs->last_clust);
			disk_write(fs->drive, fs->win, fs->fsi_sector, 1);
			fs->fsi_flag = 0;
		}
		/* Make sure that no pending write process in the physical drive */
		if (disk_ioctl(fs->drive, CTRL_SYNC, (void*)NULL) != RES_OK)
			res = FR_DISK_ERR;
	}

	return res;
}
#endif




/*-----------------------------------------------------------------------*/
/* FAT access - Read value of a FAT entry                                */
/*-----------------------------------------------------------------------*/

static
DWORD get_fat (	/* 0xFFFFFFFF:Disk error, 1:Interal error, Else:Cluster status */
	FATFS *fs,	/* File system object */
	DWORD clst	/* Cluster# to get the link information */
)
{
	UINT wc, bc;
	DWORD fsect;


	if (clst < 2 || clst >= fs->max_clust)	/* Range check */
		return 1;

	fsect = fs->fatbase;
	switch (fs->fs_type) {
	case FS_FAT12 :
		bc = clst; bc += bc / 2;
		if (move_window(fs, fsect + (bc / SS(fs)))) break;
		wc = fs->win[bc & (SS(fs) - 1)]; bc++;
		if (move_window(fs, fsect + (bc / SS(fs)))) break;
		wc |= (WORD)fs->win[bc & (SS(fs) - 1)] << 8;
		return (clst & 1) ? (wc >> 4) : (wc & 0xFFF);

	case FS_FAT16 :
		if (move_window(fs, fsect + (clst / (SS(fs) / 2)))) break;
		return LD_WORD(&fs->win[((WORD)clst * 2) & (SS(fs) - 1)]);

	case FS_FAT32 :
		if (move_window(fs, fsect + (clst / (SS(fs) / 4)))) break;
		return LD_DWORD(&fs->win[((WORD)clst * 4) & (SS(fs) - 1)]) & 0x0FFFFFFF;
	}

	return 0xFFFFFFFF;	/* An error occured at the disk I/O layer */
}




/*-----------------------------------------------------------------------*/
/* FAT access - Change value of a FAT entry                              */
/*-----------------------------------------------------------------------*/
#if !_FS_READONLY
static
FRESULT put_fat (
	FATFS *fs,	/* File system object */
	DWORD clst,	/* Cluster# to be changed in range of 2 to fs->max_clust - 1 */
	DWORD val	/* New value to mark the cluster */
)
{
	UINT bc;
	BYTE *p;
	DWORD fsect;
	FRESULT res;


	if (clst < 2 || clst >= fs->max_clust) {	/* Range check */
		res = FR_INT_ERR;

	} else {
		fsect = fs->fatbase;
		switch (fs->fs_type) {
		case FS_FAT12 :
			bc = clst; bc += bc / 2;
			res = move_window(fs, fsect + (bc / SS(fs)));
			if (res != FR_OK) break;
			p = &fs->win[bc & (SS(fs) - 1)];
			*p = (clst & 1) ? ((*p & 0x0F) | ((BYTE)val << 4)) : (BYTE)val;
			bc++;
			fs->wflag = 1;
			res = move_window(fs, fsect + (bc / SS(fs)));
			if (res != FR_OK) break;
			p = &fs->win[bc & (SS(fs) - 1)];
			*p = (clst & 1) ? (BYTE)(val >> 4) : ((*p & 0xF0) | ((BYTE)(val >> 8) & 0x0F));
			break;

		case FS_FAT16 :
			res = move_window(fs, fsect + (clst / (SS(fs) / 2)));
			if (res != FR_OK) break;
			ST_WORD(&fs->win[((WORD)clst * 2) & (SS(fs) - 1)], (WORD)val);
			break;

		case FS_FAT32 :
			res = move_window(fs, fsect + (clst / (SS(fs) / 4)));
			if (res != FR_OK) break;
			ST_DWORD(&fs->win[((WORD)clst * 4) & (SS(fs) - 1)], val);
			break;

		default :
			res = FR_INT_ERR;
		}
		fs->wflag = 1;
	}

	return res;
}
#endif /* !_FS_READONLY */