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Release 4.14 drivers/watchdog/pnx833x_wdt.c

Directory: drivers/watchdog
/*
 *  PNX833x Hardware Watchdog Driver
 *  Copyright 2008 NXP Semiconductors
 *  Daniel Laird <daniel.j.laird@nxp.com>
 *  Andre McCurdy <andre.mccurdy@nxp.com>
 *
 *  Heavily based upon - IndyDog        0.3
 *  A Hardware Watchdog Device for SGI IP22
 *
 * (c) Copyright 2002 Guido Guenther <agx@sigxcpu.org>, All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 * based on softdog.c by Alan Cox <alan@redhat.com>
 */


#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/mm.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <asm/mach-pnx833x/pnx833x.h>


#define WATCHDOG_TIMEOUT 30		
/* 30 sec Maximum timeout */

#define WATCHDOG_COUNT_FREQUENCY 68000000U 
/* Watchdog counts at 68MHZ. */

#define	PNX_WATCHDOG_TIMEOUT	(WATCHDOG_TIMEOUT * WATCHDOG_COUNT_FREQUENCY)

#define PNX_TIMEOUT_VALUE	2040000000U

/** CONFIG block */

#define PNX833X_CONFIG                      (0x07000U)

#define PNX833X_CONFIG_CPU_WATCHDOG         (0x54)

#define PNX833X_CONFIG_CPU_WATCHDOG_COMPARE (0x58)

#define PNX833X_CONFIG_CPU_COUNTERS_CONTROL (0x1c)

/** RESET block */

#define PNX833X_RESET                       (0x08000U)

#define PNX833X_RESET_CONFIG                (0x08)


static int pnx833x_wdt_alive;

/* Set default timeout in MHZ.*/

static int pnx833x_wdt_timeout = PNX_WATCHDOG_TIMEOUT;
module_param(pnx833x_wdt_timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in Mhz. (68Mhz clock), default="
			__MODULE_STRING(PNX_TIMEOUT_VALUE) "(30 seconds).");


static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
					__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");


#define START_DEFAULT	1

static int start_enabled = START_DEFAULT;
module_param(start_enabled, int, 0);
MODULE_PARM_DESC(start_enabled, "Watchdog is started on module insertion "
				"(default=" __MODULE_STRING(START_DEFAULT) ")");


static void pnx833x_wdt_start(void) { /* Enable watchdog causing reset. */ PNX833X_REG(PNX833X_RESET + PNX833X_RESET_CONFIG) |= 0x1; /* Set timeout.*/ PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout; /* Enable watchdog. */ PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_COUNTERS_CONTROL) |= 0x1; pr_info("Started watchdog timer\n"); }

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Daniel Laird4093.02%150.00%
Joe Perches36.98%150.00%
Total43100.00%2100.00%


static void pnx833x_wdt_stop(void) { /* Disable watchdog causing reset. */ PNX833X_REG(PNX833X_RESET + PNX833X_CONFIG) &= 0xFFFFFFFE; /* Disable watchdog.*/ PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_COUNTERS_CONTROL) &= 0xFFFFFFFE; pr_info("Stopped watchdog timer\n"); }

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Daniel Laird3090.91%150.00%
Joe Perches39.09%150.00%
Total33100.00%2100.00%


static void pnx833x_wdt_ping(void) { PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = pnx833x_wdt_timeout; }

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Daniel Laird17100.00%1100.00%
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/* * Allow only one person to hold it open */
static int pnx833x_wdt_open(struct inode *inode, struct file *file) { if (test_and_set_bit(0, &pnx833x_wdt_alive)) return -EBUSY; if (nowayout) __module_get(THIS_MODULE); /* Activate timer */ if (!start_enabled) pnx833x_wdt_start(); pnx833x_wdt_ping(); pr_info("Started watchdog timer\n"); return nonseekable_open(inode, file); }

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Daniel Laird6296.88%150.00%
Joe Perches23.12%150.00%
Total64100.00%2100.00%


static int pnx833x_wdt_release(struct inode *inode, struct file *file) { /* Shut off the timer. * Lock it in if it's a module and we defined ...NOWAYOUT */ if (!nowayout) pnx833x_wdt_stop(); /* Turn the WDT off */ clear_bit(0, &pnx833x_wdt_alive); return 0; }

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Daniel Laird37100.00%1100.00%
Total37100.00%1100.00%


static ssize_t pnx833x_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) { /* Refresh the timer. */ if (len) pnx833x_wdt_ping(); return len; }

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Daniel Laird34100.00%1100.00%
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static long pnx833x_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { int options, new_timeout = 0; uint32_t timeout, timeout_left = 0; static const struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, .firmware_version = 0, .identity = "Hardware Watchdog for PNX833x", }; switch (cmd) { default: return -ENOTTY; case WDIOC_GETSUPPORT: if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))) return -EFAULT; return 0; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: return put_user(0, (int *)arg); case WDIOC_SETOPTIONS: if (get_user(options, (int *)arg)) return -EFAULT; if (options & WDIOS_DISABLECARD) pnx833x_wdt_stop(); if (options & WDIOS_ENABLECARD) pnx833x_wdt_start(); return 0; case WDIOC_KEEPALIVE: pnx833x_wdt_ping(); return 0; case WDIOC_SETTIMEOUT: { if (get_user(new_timeout, (int *)arg)) return -EFAULT; pnx833x_wdt_timeout = new_timeout; PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG_COMPARE) = new_timeout; return put_user(new_timeout, (int *)arg); } case WDIOC_GETTIMEOUT: timeout = PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG_COMPARE); return put_user(timeout, (int *)arg); case WDIOC_GETTIMELEFT: timeout_left = PNX833X_REG(PNX833X_CONFIG + PNX833X_CONFIG_CPU_WATCHDOG); return put_user(timeout_left, (int *)arg); } }

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Daniel Laird26199.62%150.00%
Wim Van Sebroeck10.38%150.00%
Total262100.00%2100.00%


static int pnx833x_wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if (code == SYS_DOWN || code == SYS_HALT) pnx833x_wdt_stop(); /* Turn the WDT off */ return NOTIFY_DONE; }

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Daniel Laird36100.00%1100.00%
Total36100.00%1100.00%

static const struct file_operations pnx833x_wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = pnx833x_wdt_write, .unlocked_ioctl = pnx833x_wdt_ioctl, .open = pnx833x_wdt_open, .release = pnx833x_wdt_release, }; static struct miscdevice pnx833x_wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &pnx833x_wdt_fops, }; static struct notifier_block pnx833x_wdt_notifier = { .notifier_call = pnx833x_wdt_notify_sys, };
static int __init watchdog_init(void) { int ret, cause; /* Lets check the reason for the reset.*/ cause = PNX833X_REG(PNX833X_RESET); /*If bit 31 is set then watchdog was cause of reset.*/ if (cause & 0x80000000) { pr_info("The system was previously reset due to the watchdog firing - please investigate...\n"); } ret = register_reboot_notifier(&pnx833x_wdt_notifier); if (ret) { pr_err("cannot register reboot notifier (err=%d)\n", ret); return ret; } ret = misc_register(&pnx833x_wdt_miscdev); if (ret) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, ret); unregister_reboot_notifier(&pnx833x_wdt_notifier); return ret; } pr_info("Hardware Watchdog Timer for PNX833x: Version 0.1\n"); if (start_enabled) pnx833x_wdt_start(); return 0; }

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Daniel Laird9588.79%150.00%
Joe Perches1211.21%150.00%
Total107100.00%2100.00%


static void __exit watchdog_exit(void) { misc_deregister(&pnx833x_wdt_miscdev); unregister_reboot_notifier(&pnx833x_wdt_notifier); }

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Daniel Laird21100.00%1100.00%
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module_init(watchdog_init); module_exit(watchdog_exit); MODULE_AUTHOR("Daniel Laird/Andre McCurdy"); MODULE_DESCRIPTION("Hardware Watchdog Device for PNX833x"); MODULE_LICENSE("GPL");

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Daniel Laird88695.06%120.00%
Joe Perches272.90%120.00%
Randy Dunlap161.72%120.00%
Wim Van Sebroeck30.32%240.00%
Total932100.00%5100.00%
Directory: drivers/watchdog
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