uffs_device.c

nandflash文件系统源代码

/*
    Copyright (C) 2005-2008  Ricky Zheng <[e-mail]>

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

*/
/**
 * \file uffs_device.c
 * \brief uffs device operation
 * \author Ricky Zheng, created 10th May, 2005
 */
#include "uffs/uffs_device.h"
#include "uffs/uffs_os.h"
#include "uffs/uffs_public.h"
#include <string.h>

#define PFX "dev:"

static struct uffs_mountTableSt *g_mtabHead = NULL;

uffs_mountTable * uffs_GetMountTable(void)
{
	return g_mtabHead;
}

int uffs_RegisterMountTable(uffs_mountTable *mtab)
{
	uffs_mountTable *work = g_mtabHead;

	if (mtab == NULL) return -1;

	if (work == NULL) {
		g_mtabHead = mtab;
		return 0;
	}

	while(work) {
		if (mtab == work) {
			/* already registered */
			return 0;
		}
		if (work->next == NULL) {
			work->next = mtab;
			mtab->next = NULL;
			return 0;
		}
		work = work->next;
	}

	return -1;
}

uffs_Device * uffs_GetDevice(const char *mountPoint)
{
	struct uffs_mountTableSt *devTab = uffs_GetMountTable();
	while(devTab) {
		if(strcmp(mountPoint, devTab->mountPoint) == 0) {
			devTab->dev->refCount++;
			return devTab->dev;
		}
		devTab = devTab->next;
	}
	return NULL;
}

const char * uffs_GetDeviceMountPoint(uffs_Device *dev)
{
	struct uffs_mountTableSt * devTab = uffs_GetMountTable();
	while(devTab) {
		if(devTab->dev == dev) {
			return devTab->mountPoint;
		}
		devTab = devTab->next;
	}
	return NULL;	
}

void uffs_PutDevice(uffs_Device *dev)
{
	dev->refCount--;
}

URET uffs_DeviceInitLock(uffs_Device *dev)
{
	dev->lock.sem = uffs_SemCreate(1);
	dev->lock.task_id = UFFS_TASK_ID_NOT_EXIST;
	dev->lock.counter = 0;

	return U_SUCC;
}

URET uffs_DeviceReleaseLock(uffs_Device *dev)
{
	if (dev->lock.sem) {
		uffs_SemDelete(dev->lock.sem);
		dev->lock.sem = 0;
	}
	return U_SUCC;
}

URET uffs_DeviceLock(uffs_Device *dev)
{

	uffs_SemWait(dev->lock.sem);
	
	if (dev->lock.counter != 0) {
		uffs_Perror(UFFS_ERR_NORMAL, PFX"Lock device, counter %d NOT zero?!\n", dev->lock.counter);
	}

	dev->lock.counter++;

	return U_SUCC;
}

URET uffs_DeviceUnLock(uffs_Device *dev)
{

	dev->lock.counter--;

	if (dev->lock.counter != 0) {
		uffs_Perror(UFFS_ERR_NORMAL, PFX"Unlock device, counter %d NOT zero?!\n", dev->lock.counter);
	}
	
	uffs_SemSignal(dev->lock.sem);

	return U_SUCC;
}