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Commit 88cce427 authored by Philippe De Muyter's avatar Philippe De Muyter Committed by Wim Van Sebroeck
Browse files

watchdog: Add MCF548x watchdog driver. 



Add watchdog driver for MCF548x.

Signed-off-by: default avatarPhilippe De Muyter <phdm@macqel.be>
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
parent f8394f61

arch/m68k/include/asm/m548xgpt.h

+2 −0
Original line number Diff line number Diff line
@@ -59,11 +59,13 @@ 
#define MCF_GPT_GMS_GPIO_INPUT     (0x00000000)

#define MCF_GPT_GMS_GPIO_OUTLO     (0x00000020)

#define MCF_GPT_GMS_GPIO_OUTHI     (0x00000030)

#define MCF_GPT_GMS_GPIO_MASK      (0x00000030)

#define MCF_GPT_GMS_TMS_DISABLE    (0x00000000)

#define MCF_GPT_GMS_TMS_INCAPT     (0x00000001)

#define MCF_GPT_GMS_TMS_OUTCAPT    (0x00000002)

#define MCF_GPT_GMS_TMS_PWM        (0x00000003)

#define MCF_GPT_GMS_TMS_GPIO       (0x00000004)

#define MCF_GPT_GMS_TMS_MASK       (0x00000007)



/* Bit definitions and macros for MCF_GPT_GCIR */

#define MCF_GPT_GCIR_CNT(x)        (((x)&0x0000FFFF)<<0)

drivers/watchdog/Kconfig

+6 −1
Original line number Diff line number Diff line
@@ -862,7 +862,12 @@ config SBC_EPX_C3_WATCHDOG 


# M68K Architecture



# M68KNOMMU Architecture

config M548x_WATCHDOG

	tristate "MCF548x watchdog support"

	depends on M548x

	help

	  To compile this driver as a module, choose M here: the

	  module will be called m548x_wdt.



# MIPS Architecture

drivers/watchdog/Makefile

+1 −2
Original line number Diff line number Diff line
@@ -106,8 +106,7 @@ obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o 
# M32R Architecture



# M68K Architecture



# M68KNOMMU Architecture

obj-$(CONFIG_M548x_WATCHDOG) += m548x_wdt.o



# MIPS Architecture

obj-$(CONFIG_ATH79_WDT) += ath79_wdt.o

drivers/watchdog/m548x_wdt.c

0 → 100644
+227 −0
Original line number Diff line number Diff line 
/*

 * drivers/watchdog/m548x_wdt.c

 *

 * Watchdog driver for ColdFire MCF548x processors

 * Copyright 2010 (c) Philippe De Muyter <phdm@macqel.be>

 *

 * Adapted from the IXP4xx watchdog driver, which carries these notices:

 *

 *  Author: Deepak Saxena <dsaxena@plexity.net>

 *

 *  Copyright 2004 (c) MontaVista, Software, Inc.

 *  Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu>

 *

 * This file is licensed under  the terms of the GNU General Public

 * License version 2. This program is licensed "as is" without any

 * warranty of any kind, whether express or implied.

 */



#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/fs.h>

#include <linux/miscdevice.h>

#include <linux/watchdog.h>

#include <linux/init.h>

#include <linux/bitops.h>

#include <linux/ioport.h>

#include <linux/uaccess.h>



#include <asm/coldfire.h>

#include <asm/m548xsim.h>

#include <asm/m548xgpt.h>



static int nowayout = WATCHDOG_NOWAYOUT;

static unsigned int heartbeat = 30;	/* (secs) Default is 0.5 minute */

static unsigned long wdt_status;



#define	WDT_IN_USE		0

#define	WDT_OK_TO_CLOSE		1



static void wdt_enable(void)

{

	unsigned int gms0;



	/* preserve GPIO usage, if any */

	gms0 = __raw_readl(MCF_MBAR + MCF_GPT_GMS0);

	if (gms0 & MCF_GPT_GMS_TMS_GPIO)

		gms0 &= (MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_GPIO_MASK

							| MCF_GPT_GMS_OD);

	else

		gms0 = MCF_GPT_GMS_TMS_GPIO | MCF_GPT_GMS_OD;

	__raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);

	__raw_writel(MCF_GPT_GCIR_PRE(heartbeat*(MCF_BUSCLK/0xffff)) |

			MCF_GPT_GCIR_CNT(0xffff), MCF_MBAR + MCF_GPT_GCIR0);

	gms0 |= MCF_GPT_GMS_OCPW(0xA5) | MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE;

	__raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);

}



static void wdt_disable(void)

{

	unsigned int gms0;



	/* disable watchdog */

	gms0 = __raw_readl(MCF_MBAR + MCF_GPT_GMS0);

	gms0 &= ~(MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE);

	__raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);

}



static void wdt_keepalive(void)

{

	unsigned int gms0;



	gms0 = __raw_readl(MCF_MBAR + MCF_GPT_GMS0);

	gms0 |= MCF_GPT_GMS_OCPW(0xA5);

	__raw_writel(gms0, MCF_MBAR + MCF_GPT_GMS0);

}



static int m548x_wdt_open(struct inode *inode, struct file *file)

{

	if (test_and_set_bit(WDT_IN_USE, &wdt_status))

		return -EBUSY;



	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);

	wdt_enable();

	return nonseekable_open(inode, file);

}



static ssize_t m548x_wdt_write(struct file *file, const char *data,

						size_t len, loff_t *ppos)

{

	if (len) {

		if (!nowayout) {

			size_t i;



			clear_bit(WDT_OK_TO_CLOSE, &wdt_status);



			for (i = 0; i != len; i++) {

				char c;



				if (get_user(c, data + i))

					return -EFAULT;

				if (c == 'V')

					set_bit(WDT_OK_TO_CLOSE, &wdt_status);

			}

		}

		wdt_keepalive();

	}

	return len;

}



static const struct watchdog_info ident = {

	.options	= WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |

				WDIOF_KEEPALIVEPING,

	.identity	= "Coldfire M548x Watchdog",

};



static long m548x_wdt_ioctl(struct file *file, unsigned int cmd,

							 unsigned long arg)

{

	int ret = -ENOTTY;

	int time;



	switch (cmd) {

	case WDIOC_GETSUPPORT:

		ret = copy_to_user((struct watchdog_info *)arg, &ident,

				   sizeof(ident)) ? -EFAULT : 0;

		break;



	case WDIOC_GETSTATUS:

		ret = put_user(0, (int *)arg);

		break;



	case WDIOC_GETBOOTSTATUS:

		ret = put_user(0, (int *)arg);

		break;



	case WDIOC_KEEPALIVE:

		wdt_keepalive();

		ret = 0;

		break;



	case WDIOC_SETTIMEOUT:

		ret = get_user(time, (int *)arg);

		if (ret)

			break;



		if (time <= 0 || time > 30) {

			ret = -EINVAL;

			break;

		}



		heartbeat = time;

		wdt_enable();

		/* Fall through */



	case WDIOC_GETTIMEOUT:

		ret = put_user(heartbeat, (int *)arg);

		break;

	}

	return ret;

}



static int m548x_wdt_release(struct inode *inode, struct file *file)

{

	if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))

		wdt_disable();

	else {

		printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - "

					"timer will not stop\n");

		wdt_keepalive();

	}

	clear_bit(WDT_IN_USE, &wdt_status);

	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);



	return 0;

}





static const struct file_operations m548x_wdt_fops = {

	.owner		= THIS_MODULE,

	.llseek		= no_llseek,

	.write		= m548x_wdt_write,

	.unlocked_ioctl	= m548x_wdt_ioctl,

	.open		= m548x_wdt_open,

	.release	= m548x_wdt_release,

};



static struct miscdevice m548x_wdt_miscdev = {

	.minor		= WATCHDOG_MINOR,

	.name		= "watchdog",

	.fops		= &m548x_wdt_fops,

};



static int __init m548x_wdt_init(void)

{

	if (!request_mem_region(MCF_MBAR + MCF_GPT_GCIR0, 4,

						"Coldfire M548x Watchdog")) {

		printk(KERN_WARNING

				"Coldfire M548x Watchdog : I/O region busy\n");

		return -EBUSY;

	}

	printk(KERN_INFO "ColdFire watchdog driver is loaded.\n");



	return misc_register(&m548x_wdt_miscdev);

}



static void __exit m548x_wdt_exit(void)

{

	misc_deregister(&m548x_wdt_miscdev);

	release_mem_region(MCF_MBAR + MCF_GPT_GCIR0, 4);

}



module_init(m548x_wdt_init);

module_exit(m548x_wdt_exit);



MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");

MODULE_DESCRIPTION("Coldfire M548x Watchdog");



module_param(heartbeat, int, 0);

MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 30s)");



module_param(nowayout, int, 0);

MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");



MODULE_LICENSE("GPL");

MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);