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Commit 2c22120f authored by Kyungmin Park's avatar Kyungmin Park
Browse files

MTD: OneNAND: interrupt based wait support 

  We can use the two methods to wait.
  1. polling: read interrupt status register
  2. interrupt: use kernel ineterrupt mechanism

  To use interrupt method, you first connect onenand interrupt pin to your
platform and configure interrupt properly

Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
parent ff0dab64

drivers/mtd/onenand/generic.c

+1 −0
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ static int __devinit generic_onenand_probe(struct device *dev) 
	}



	info->onenand.mmcontrol = pdata->mmcontrol;

	info->onenand.irq = platform_get_irq(pdev, 0);



	info->mtd.name = pdev->dev.bus_id;

	info->mtd.priv = &info->onenand;

drivers/mtd/onenand/onenand_base.c

+107 −2
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/module.h>

#include <linux/init.h>

#include <linux/sched.h>

#include <linux/interrupt.h>

#include <linux/jiffies.h>

#include <linux/mtd/mtd.h>

#include <linux/mtd/onenand.h>
@@ -339,6 +340,111 @@ static int onenand_wait(struct mtd_info *mtd, int state) 
	return 0;

}



/*

 * onenand_interrupt - [DEFAULT] onenand interrupt handler

 * @param irq		onenand interrupt number

 * @param dev_id	interrupt data

 *

 * complete the work

 */

static irqreturn_t onenand_interrupt(int irq, void *data)

{

	struct onenand_chip *this = (struct onenand_chip *) data;



	/* To handle shared interrupt */

	if (!this->complete.done)

		complete(&this->complete);



	return IRQ_HANDLED;

}



/*

 * onenand_interrupt_wait - [DEFAULT] wait until the command is done

 * @param mtd		MTD device structure

 * @param state		state to select the max. timeout value

 *

 * Wait for command done.

 */

static int onenand_interrupt_wait(struct mtd_info *mtd, int state)

{

	struct onenand_chip *this = mtd->priv;



	/* To prevent soft lockup */

	touch_softlockup_watchdog();



	wait_for_completion(&this->complete);



	return onenand_wait(mtd, state);

}



/*

 * onenand_try_interrupt_wait - [DEFAULT] try interrupt wait

 * @param mtd		MTD device structure

 * @param state		state to select the max. timeout value

 *

 * Try interrupt based wait (It is used one-time)

 */

static int onenand_try_interrupt_wait(struct mtd_info *mtd, int state)

{

	struct onenand_chip *this = mtd->priv;

	unsigned long remain, timeout;



	/* We use interrupt wait first */

	this->wait = onenand_interrupt_wait;



	/* To prevent soft lockup */

	touch_softlockup_watchdog();



	timeout = msecs_to_jiffies(100);

	remain = wait_for_completion_timeout(&this->complete, timeout);

	if (!remain) {

		printk(KERN_INFO "OneNAND: There's no interrupt. "

				"We use the normal wait\n");



		/* Release the irq */

		free_irq(this->irq, this);

		

		this->wait = onenand_wait;

	}



	return onenand_wait(mtd, state);

}



/*

 * onenand_setup_wait - [OneNAND Interface] setup onenand wait method

 * @param mtd		MTD device structure

 *

 * There's two method to wait onenand work

 * 1. polling - read interrupt status register

 * 2. interrupt - use the kernel interrupt method

 */

static void onenand_setup_wait(struct mtd_info *mtd)

{

	struct onenand_chip *this = mtd->priv;

	int syscfg;



	init_completion(&this->complete);



	if (this->irq <= 0) {

		this->wait = onenand_wait;

		return;

	}



	if (request_irq(this->irq, &onenand_interrupt,

				IRQF_SHARED, "onenand", this)) {

		/* If we can't get irq, use the normal wait */

		this->wait = onenand_wait;

		return;

	}



	/* Enable interrupt */

	syscfg = this->read_word(this->base + ONENAND_REG_SYS_CFG1);

	syscfg |= ONENAND_SYS_CFG1_IOBE;

	this->write_word(syscfg, this->base + ONENAND_REG_SYS_CFG1);



	this->wait = onenand_try_interrupt_wait;

}



/**

 * onenand_bufferram_offset - [DEFAULT] BufferRAM offset

 * @param mtd		MTD data structure
@@ -1129,7 +1235,6 @@ static void onenand_sync(struct mtd_info *mtd) 
	onenand_release_device(mtd);

}





/**

 * onenand_block_isbad - [MTD Interface] Check whether the block at the given offset is bad

 * @param mtd		MTD device structure
@@ -1846,7 +1951,7 @@ int onenand_scan(struct mtd_info *mtd, int maxchips) 
	if (!this->command)

		this->command = onenand_command;

	if (!this->wait)

		this->wait = onenand_wait;

		onenand_setup_wait(mtd);



	if (!this->read_bufferram)

		this->read_bufferram = onenand_read_bufferram;

include/linux/mtd/onenand.h

+4 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#define __LINUX_MTD_ONENAND_H



#include <linux/spinlock.h>

#include <linux/completion.h>

#include <linux/mtd/onenand_regs.h>

#include <linux/mtd/bbm.h>
@@ -120,6 +121,9 @@ struct onenand_chip { 
	int (*block_markbad)(struct mtd_info *mtd, loff_t ofs);

	int (*scan_bbt)(struct mtd_info *mtd);



	struct completion	complete;

	int			irq;



	spinlock_t		chip_lock;

	wait_queue_head_t	wq;

	onenand_state_t		state;