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Commit 962034f4 authored by Vitaly Wool's avatar Vitaly Wool Committed by Thomas Gleixner
Browse files

[MTD] NAND: Add suspend/resume functionality 



The changes introduced allow to suspend/resume NAND flash.
A new state (FL_PM_SUSPENDED) is introduced, as well as
routines for mtd->suspend and mtd->resume to put the flash in
suspended state from software pov.

Signed-off-by: default avatarVitaly Wool <vwool@ru.mvista.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 9c517e6c

drivers/mtd/nand/nand_base.c

+40 −6
Original line number Diff line number Diff line
@@ -46,6 +46,8 @@ 
 *		perform extra error status checks on erase and write failures.  This required

 *		adding a wrapper function for nand_read_ecc.

 *

 * 08-20-2005	vwool: suspend/resume added

 *

 * Credits:

 *	David Woodhouse for adding multichip support  

 *
@@ -59,7 +61,7 @@ 
 *	The AG-AND chips have nice features for speed improvement,

 *	which are not supported yet. Read / program 4 pages in one go.

 *

 * $Id: nand_base.c,v 1.148 2005/08/04 17:14:48 gleixner Exp $

 * $Id: nand_base.c,v 1.150 2005/09/15 13:58:48 vwool Exp $

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as
@@ -153,7 +155,7 @@ static int nand_verify_pages (struct mtd_info *mtd, struct nand_chip *this, int 
#define nand_verify_pages(...) (0)

#endif

		

static void nand_get_device (struct nand_chip *this, struct mtd_info *mtd, int new_state);

static int nand_get_device (struct nand_chip *this, struct mtd_info *mtd, int new_state);



/**

 * nand_release_device - [GENERIC] release chip
@@ -756,7 +758,7 @@ static void nand_command_lp (struct mtd_info *mtd, unsigned command, int column, 
 *

 * Get the device and lock it for exclusive access

 */

static void nand_get_device (struct nand_chip *this, struct mtd_info *mtd, int new_state)

static int nand_get_device (struct nand_chip *this, struct mtd_info *mtd, int new_state)

{

	struct nand_chip *active;

	spinlock_t *lock;
@@ -779,7 +781,11 @@ retry: 
	if (active == this && this->state == FL_READY) {

		this->state = new_state;

		spin_unlock(lock);

		return;

		return 0;

	}

	if (new_state == FL_PM_SUSPENDED) {

		spin_unlock(lock);

		return (this->state == FL_PM_SUSPENDED) ? 0 : -EAGAIN;

	}

	set_current_state(TASK_UNINTERRUPTIBLE);

	add_wait_queue(wq, &wait);
@@ -2284,6 +2290,34 @@ static int nand_block_markbad (struct mtd_info *mtd, loff_t ofs) 
	return this->block_markbad(mtd, ofs);

}



/**

 * nand_suspend - [MTD Interface] Suspend the NAND flash

 * @mtd:	MTD device structure

 */

static int nand_suspend(struct mtd_info *mtd)

{

	struct nand_chip *this = mtd->priv;



	return nand_get_device (this, mtd, FL_PM_SUSPENDED);

}



/**

 * nand_resume - [MTD Interface] Resume the NAND flash

 * @mtd:	MTD device structure

 */

static void nand_resume(struct mtd_info *mtd)

{

	struct nand_chip *this = mtd->priv;



	if (this->state == FL_PM_SUSPENDED)

		nand_release_device(mtd);

	else

		printk(KERN_ERR "resume() called for the chip which is not "

				"in suspended state\n");



}





/**

 * nand_scan - [NAND Interface] Scan for the NAND device

 * @mtd:	MTD device structure
@@ -2643,8 +2677,8 @@ int nand_scan (struct mtd_info *mtd, int maxchips) 
	mtd->sync = nand_sync;

	mtd->lock = NULL;

	mtd->unlock = NULL;

	mtd->suspend = NULL;

	mtd->resume = NULL;

	mtd->suspend = nand_suspend;

	mtd->resume = nand_resume;

	mtd->block_isbad = nand_block_isbad;

	mtd->block_markbad = nand_block_markbad;

include/linux/mtd/nand.h

+2 −1
Original line number Diff line number Diff line
@@ -5,7 +5,7 @@ 
 *                     Steven J. Hill <sjhill@realitydiluted.com>

 *		       Thomas Gleixner <tglx@linutronix.de>

 *

 * $Id: nand.h,v 1.73 2005/05/31 19:39:17 gleixner Exp $

 * $Id: nand.h,v 1.74 2005/09/15 13:58:50 vwool Exp $

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as
@@ -244,6 +244,7 @@ typedef enum { 
	FL_ERASING,

	FL_SYNCING,

	FL_CACHEDPRG,

	FL_PM_SUSPENDED,

} nand_state_t;



/* Keep gcc happy */