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Release 4.14 drivers/watchdog/m54xx_wdt.c

Directory: drivers/watchdog
/*
 * drivers/watchdog/m54xx_wdt.c
 *
 * Watchdog driver for ColdFire MCF547x & 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.
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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/m54xxsim.h>
#include <asm/m54xxgpt.h>


static bool 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_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_GPT_GMS0); __raw_writel(MCF_GPT_GCIR_PRE(heartbeat*(MCF_BUSCLK/0xffff)) | MCF_GPT_GCIR_CNT(0xffff), MCF_GPT_GCIR0); gms0 |= MCF_GPT_GMS_OCPW(0xA5) | MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE; __raw_writel(gms0, MCF_GPT_GMS0); }

Contributors

PersonTokensPropCommitsCommitProp
Philippe De Muyter89100.00%1100.00%
Total89100.00%1100.00%


static void wdt_disable(void) { unsigned int gms0; /* disable watchdog */ gms0 = __raw_readl(MCF_GPT_GMS0); gms0 &= ~(MCF_GPT_GMS_WDEN | MCF_GPT_GMS_CE); __raw_writel(gms0, MCF_GPT_GMS0); }

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PersonTokensPropCommitsCommitProp
Philippe De Muyter36100.00%1100.00%
Total36100.00%1100.00%


static void wdt_keepalive(void) { unsigned int gms0; gms0 = __raw_readl(MCF_GPT_GMS0); gms0 |= MCF_GPT_GMS_OCPW(0xA5); __raw_writel(gms0, MCF_GPT_GMS0); }

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PersonTokensPropCommitsCommitProp
Philippe De Muyter33100.00%1100.00%
Total33100.00%1100.00%


static int m54xx_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); }

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PersonTokensPropCommitsCommitProp
Philippe De Muyter49100.00%2100.00%
Total49100.00%2100.00%


static ssize_t m54xx_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; }

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PersonTokensPropCommitsCommitProp
Philippe De Muyter100100.00%2100.00%
Total100100.00%2100.00%

static const struct watchdog_info ident = { .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, .identity = "Coldfire M54xx Watchdog", };
static long m54xx_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; }

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PersonTokensPropCommitsCommitProp
Philippe De Muyter175100.00%2100.00%
Total175100.00%2100.00%


static int m54xx_wdt_release(struct inode *inode, struct file *file) { if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) wdt_disable(); else { pr_crit("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; }

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PersonTokensPropCommitsCommitProp
Philippe De Muyter5796.61%266.67%
Joe Perches23.39%133.33%
Total59100.00%3100.00%

static const struct file_operations m54xx_wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = m54xx_wdt_write, .unlocked_ioctl = m54xx_wdt_ioctl, .open = m54xx_wdt_open, .release = m54xx_wdt_release, }; static struct miscdevice m54xx_wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &m54xx_wdt_fops, };
static int __init m54xx_wdt_init(void) { if (!request_mem_region(MCF_GPT_GCIR0, 4, "Coldfire M54xx Watchdog")) { pr_warn("I/O region busy\n"); return -EBUSY; } pr_info("driver is loaded\n"); return misc_register(&m54xx_wdt_miscdev); }

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PersonTokensPropCommitsCommitProp
Philippe De Muyter4090.91%266.67%
Joe Perches49.09%133.33%
Total44100.00%3100.00%


static void __exit m54xx_wdt_exit(void) { misc_deregister(&m54xx_wdt_miscdev); release_mem_region(MCF_GPT_GCIR0, 4); }

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PersonTokensPropCommitsCommitProp
Philippe De Muyter22100.00%2100.00%
Total22100.00%2100.00%

module_init(m54xx_wdt_init); module_exit(m54xx_wdt_exit); MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>"); MODULE_DESCRIPTION("Coldfire M54xx Watchdog"); module_param(heartbeat, int, 0); MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 30s)"); module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
Philippe De Muyter80998.18%250.00%
Joe Perches131.58%125.00%
Wim Van Sebroeck20.24%125.00%
Total824100.00%4100.00%
Directory: drivers/watchdog
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