From 962034f43937d02a1c18e802a6641aed0a266ac5 Mon Sep 17 00:00:00 2001 From: Vitaly Wool Date: Thu, 15 Sep 2005 14:58:53 +0100 Subject: [PATCH] [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: Vitaly Wool Signed-off-by: Thomas Gleixner --- drivers/mtd/nand/nand_base.c | 46 +++++++++++++++++++++++++++++++----- include/linux/mtd/nand.h | 3 ++- 2 files changed, 42 insertions(+), 7 deletions(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index cdf108619344..4e22317397e8 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -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; diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 9b5b76217584..2d36413b2f94 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -5,7 +5,7 @@ * Steven J. Hill * Thomas Gleixner * - * $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 */ -- 2.39.5