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476 lines
10 KiB
476 lines
10 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Eurotech CPU-1220/1410/1420 on board WDT driver |
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* |
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* (c) Copyright 2001 Ascensit <[email protected]> |
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* (c) Copyright 2001 Rodolfo Giometti <[email protected]> |
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* (c) Copyright 2002 Rob Radez <[email protected]> |
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* |
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* Based on wdt.c. |
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* Original copyright messages: |
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* |
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* (c) Copyright 1996-1997 Alan Cox <[email protected]>, |
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* All Rights Reserved. |
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* |
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* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide |
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* warranty for any of this software. This material is provided |
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* "AS-IS" and at no charge. |
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* |
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* (c) Copyright 1995 Alan Cox <[email protected]>* |
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*/ |
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/* Changelog: |
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* |
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* 2001 - Rodolfo Giometti |
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* Initial release |
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* |
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* 2002/04/25 - Rob Radez |
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* clean up #includes |
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* clean up locking |
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* make __setup param unique |
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* proper options in watchdog_info |
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* add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls |
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* add expect_close support |
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* |
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* 2002.05.30 - Joel Becker <[email protected]> |
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* Added Matt Domsch's nowayout module option. |
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*/ |
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/* |
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* The eurotech CPU-1220/1410/1420's watchdog is a part |
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* of the on-board SUPER I/O device SMSC FDC 37B782. |
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*/ |
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
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#include <linux/interrupt.h> |
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#include <linux/module.h> |
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#include <linux/moduleparam.h> |
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#include <linux/types.h> |
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#include <linux/miscdevice.h> |
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#include <linux/watchdog.h> |
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#include <linux/fs.h> |
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#include <linux/ioport.h> |
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#include <linux/notifier.h> |
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#include <linux/reboot.h> |
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#include <linux/init.h> |
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#include <linux/io.h> |
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#include <linux/uaccess.h> |
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static unsigned long eurwdt_is_open; |
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static int eurwdt_timeout; |
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static char eur_expect_close; |
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static DEFINE_SPINLOCK(eurwdt_lock); |
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/* |
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* You must set these - there is no sane way to probe for this board. |
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*/ |
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static int io = 0x3f0; |
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static int irq = 10; |
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static char *ev = "int"; |
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#define WDT_TIMEOUT 60 /* 1 minute */ |
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static bool nowayout = WATCHDOG_NOWAYOUT; |
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module_param(nowayout, bool, 0); |
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MODULE_PARM_DESC(nowayout, |
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"Watchdog cannot be stopped once started (default=" |
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
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/* |
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* Some symbolic names |
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*/ |
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#define WDT_CTRL_REG 0x30 |
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#define WDT_OUTPIN_CFG 0xe2 |
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#define WDT_EVENT_INT 0x00 |
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#define WDT_EVENT_REBOOT 0x08 |
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#define WDT_UNIT_SEL 0xf1 |
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#define WDT_UNIT_SECS 0x80 |
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#define WDT_TIMEOUT_VAL 0xf2 |
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#define WDT_TIMER_CFG 0xf3 |
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module_param_hw(io, int, ioport, 0); |
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MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)"); |
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module_param_hw(irq, int, irq, 0); |
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MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)"); |
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module_param(ev, charp, 0); |
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MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')"); |
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/* |
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* Programming support |
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*/ |
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static inline void eurwdt_write_reg(u8 index, u8 data) |
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{ |
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outb(index, io); |
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outb(data, io+1); |
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} |
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static inline void eurwdt_lock_chip(void) |
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{ |
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outb(0xaa, io); |
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} |
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static inline void eurwdt_unlock_chip(void) |
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{ |
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outb(0x55, io); |
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eurwdt_write_reg(0x07, 0x08); /* set the logical device */ |
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} |
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static inline void eurwdt_set_timeout(int timeout) |
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{ |
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eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout); |
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} |
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static inline void eurwdt_disable_timer(void) |
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{ |
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eurwdt_set_timeout(0); |
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} |
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static void eurwdt_activate_timer(void) |
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{ |
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eurwdt_disable_timer(); |
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eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */ |
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eurwdt_write_reg(WDT_OUTPIN_CFG, |
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!strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT); |
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/* Setting interrupt line */ |
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if (irq == 2 || irq > 15 || irq < 0) { |
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pr_err("invalid irq number\n"); |
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irq = 0; /* if invalid we disable interrupt */ |
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} |
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if (irq == 0) |
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pr_info("interrupt disabled\n"); |
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eurwdt_write_reg(WDT_TIMER_CFG, irq << 4); |
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eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */ |
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eurwdt_set_timeout(0); /* the default timeout */ |
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} |
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/* |
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* Kernel methods. |
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*/ |
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static irqreturn_t eurwdt_interrupt(int irq, void *dev_id) |
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{ |
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pr_crit("timeout WDT timeout\n"); |
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#ifdef ONLY_TESTING |
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pr_crit("Would Reboot\n"); |
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#else |
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pr_crit("Initiating system reboot\n"); |
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emergency_restart(); |
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#endif |
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return IRQ_HANDLED; |
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} |
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/** |
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* eurwdt_ping: |
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* |
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* Reload counter one with the watchdog timeout. |
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*/ |
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static void eurwdt_ping(void) |
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{ |
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/* Write the watchdog default value */ |
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eurwdt_set_timeout(eurwdt_timeout); |
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} |
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/** |
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* eurwdt_write: |
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* @file: file handle to the watchdog |
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* @buf: buffer to write (unused as data does not matter here |
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* @count: count of bytes |
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* @ppos: pointer to the position to write. No seeks allowed |
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* |
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* A write to a watchdog device is defined as a keepalive signal. Any |
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* write of data will do, as we we don't define content meaning. |
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*/ |
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static ssize_t eurwdt_write(struct file *file, const char __user *buf, |
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size_t count, loff_t *ppos) |
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{ |
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if (count) { |
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if (!nowayout) { |
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size_t i; |
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eur_expect_close = 0; |
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for (i = 0; i != count; i++) { |
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char c; |
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if (get_user(c, buf + i)) |
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return -EFAULT; |
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if (c == 'V') |
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eur_expect_close = 42; |
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} |
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} |
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spin_lock(&eurwdt_lock); |
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eurwdt_ping(); /* the default timeout */ |
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spin_unlock(&eurwdt_lock); |
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} |
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return count; |
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} |
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/** |
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* eurwdt_ioctl: |
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* @file: file handle to the device |
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* @cmd: watchdog command |
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* @arg: argument pointer |
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* |
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* The watchdog API defines a common set of functions for all watchdogs |
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* according to their available features. |
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*/ |
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static long eurwdt_ioctl(struct file *file, |
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unsigned int cmd, unsigned long arg) |
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{ |
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void __user *argp = (void __user *)arg; |
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int __user *p = argp; |
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static const struct watchdog_info ident = { |
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.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
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| WDIOF_MAGICCLOSE, |
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.firmware_version = 1, |
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.identity = "WDT Eurotech CPU-1220/1410", |
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}; |
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int time; |
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int options, retval = -EINVAL; |
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switch (cmd) { |
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case WDIOC_GETSUPPORT: |
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return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; |
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case WDIOC_GETSTATUS: |
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case WDIOC_GETBOOTSTATUS: |
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return put_user(0, p); |
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case WDIOC_SETOPTIONS: |
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if (get_user(options, p)) |
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return -EFAULT; |
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spin_lock(&eurwdt_lock); |
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if (options & WDIOS_DISABLECARD) { |
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eurwdt_disable_timer(); |
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retval = 0; |
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} |
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if (options & WDIOS_ENABLECARD) { |
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eurwdt_activate_timer(); |
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eurwdt_ping(); |
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retval = 0; |
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} |
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spin_unlock(&eurwdt_lock); |
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return retval; |
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case WDIOC_KEEPALIVE: |
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spin_lock(&eurwdt_lock); |
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eurwdt_ping(); |
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spin_unlock(&eurwdt_lock); |
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return 0; |
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case WDIOC_SETTIMEOUT: |
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if (copy_from_user(&time, p, sizeof(int))) |
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return -EFAULT; |
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/* Sanity check */ |
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if (time < 0 || time > 255) |
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return -EINVAL; |
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spin_lock(&eurwdt_lock); |
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eurwdt_timeout = time; |
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eurwdt_set_timeout(time); |
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spin_unlock(&eurwdt_lock); |
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fallthrough; |
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case WDIOC_GETTIMEOUT: |
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return put_user(eurwdt_timeout, p); |
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default: |
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return -ENOTTY; |
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} |
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} |
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/** |
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* eurwdt_open: |
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* @inode: inode of device |
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* @file: file handle to device |
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* |
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* The misc device has been opened. The watchdog device is single |
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* open and on opening we load the counter. |
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*/ |
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static int eurwdt_open(struct inode *inode, struct file *file) |
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{ |
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if (test_and_set_bit(0, &eurwdt_is_open)) |
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return -EBUSY; |
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eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */ |
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/* Activate the WDT */ |
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eurwdt_activate_timer(); |
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return stream_open(inode, file); |
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} |
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/** |
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* eurwdt_release: |
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* @inode: inode to board |
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* @file: file handle to board |
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* |
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* The watchdog has a configurable API. There is a religious dispute |
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* between people who want their watchdog to be able to shut down and |
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* those who want to be sure if the watchdog manager dies the machine |
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* reboots. In the former case we disable the counters, in the latter |
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* case you have to open it again very soon. |
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*/ |
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static int eurwdt_release(struct inode *inode, struct file *file) |
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{ |
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if (eur_expect_close == 42) |
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eurwdt_disable_timer(); |
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else { |
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pr_crit("Unexpected close, not stopping watchdog!\n"); |
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eurwdt_ping(); |
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} |
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clear_bit(0, &eurwdt_is_open); |
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eur_expect_close = 0; |
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return 0; |
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} |
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/** |
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* eurwdt_notify_sys: |
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* @this: our notifier block |
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* @code: the event being reported |
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* @unused: unused |
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* |
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* Our notifier is called on system shutdowns. We want to turn the card |
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* off at reboot otherwise the machine will reboot again during memory |
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* test or worse yet during the following fsck. This would suck, in fact |
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* trust me - if it happens it does suck. |
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*/ |
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static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code, |
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void *unused) |
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{ |
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if (code == SYS_DOWN || code == SYS_HALT) |
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eurwdt_disable_timer(); /* Turn the card off */ |
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return NOTIFY_DONE; |
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} |
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/* |
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* Kernel Interfaces |
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*/ |
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static const struct file_operations eurwdt_fops = { |
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.owner = THIS_MODULE, |
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.llseek = no_llseek, |
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.write = eurwdt_write, |
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.unlocked_ioctl = eurwdt_ioctl, |
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.compat_ioctl = compat_ptr_ioctl, |
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.open = eurwdt_open, |
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.release = eurwdt_release, |
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}; |
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static struct miscdevice eurwdt_miscdev = { |
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.minor = WATCHDOG_MINOR, |
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.name = "watchdog", |
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.fops = &eurwdt_fops, |
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}; |
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/* |
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* The WDT card needs to learn about soft shutdowns in order to |
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* turn the timebomb registers off. |
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*/ |
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static struct notifier_block eurwdt_notifier = { |
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.notifier_call = eurwdt_notify_sys, |
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}; |
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/** |
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* eurwdt_exit: |
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* |
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* Unload the watchdog. You cannot do this with any file handles open. |
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* If your watchdog is set to continue ticking on close and you unload |
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* it, well it keeps ticking. We won't get the interrupt but the board |
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* will not touch PC memory so all is fine. You just have to load a new |
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* module in 60 seconds or reboot. |
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*/ |
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static void __exit eurwdt_exit(void) |
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{ |
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eurwdt_lock_chip(); |
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misc_deregister(&eurwdt_miscdev); |
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unregister_reboot_notifier(&eurwdt_notifier); |
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release_region(io, 2); |
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free_irq(irq, NULL); |
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} |
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/** |
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* eurwdt_init: |
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* |
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* Set up the WDT watchdog board. After grabbing the resources |
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* we require we need also to unlock the device. |
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* The open() function will actually kick the board off. |
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*/ |
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static int __init eurwdt_init(void) |
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{ |
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int ret; |
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ret = request_irq(irq, eurwdt_interrupt, 0, "eurwdt", NULL); |
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if (ret) { |
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pr_err("IRQ %d is not free\n", irq); |
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goto out; |
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} |
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if (!request_region(io, 2, "eurwdt")) { |
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pr_err("IO %X is not free\n", io); |
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ret = -EBUSY; |
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goto outirq; |
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} |
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ret = register_reboot_notifier(&eurwdt_notifier); |
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if (ret) { |
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pr_err("can't register reboot notifier (err=%d)\n", ret); |
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goto outreg; |
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} |
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ret = misc_register(&eurwdt_miscdev); |
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if (ret) { |
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pr_err("can't misc_register on minor=%d\n", WATCHDOG_MINOR); |
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goto outreboot; |
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} |
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eurwdt_unlock_chip(); |
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ret = 0; |
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pr_info("Eurotech WDT driver 0.01 at %X (Interrupt %d) - timeout event: %s\n", |
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io, irq, (!strcmp("int", ev) ? "int" : "reboot")); |
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out: |
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return ret; |
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outreboot: |
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unregister_reboot_notifier(&eurwdt_notifier); |
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outreg: |
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release_region(io, 2); |
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outirq: |
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free_irq(irq, NULL); |
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goto out; |
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} |
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module_init(eurwdt_init); |
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module_exit(eurwdt_exit); |
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MODULE_AUTHOR("Rodolfo Giometti"); |
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MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog"); |
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MODULE_LICENSE("GPL");
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