[WATCHDOG] AR7: watchdog timer
Driver for the watchdog timer. Still doesn't reboots the machine on some boards, but we have improved and cleaned it Signed-off-by: Matteo Croce <technoboy85@gmail.com> Signed-off-by: Nicolas Thill <nico@openwrt.org> Signed-off-by: Enrik Berkhan <Enrik.Berkhan@akk.org> Signed-off-by: Christer Weinigel <wingel@nano-system.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
This commit is contained in:
Matteo Croce
Wim Van Sebroeck
parent
01ed08c14d
commit
c283cf2c09
@ -610,6 +610,12 @@ config WDT_RM9K_GPI
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To compile this driver as a module, choose M here: the
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module will be called rm9k_wdt.
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config AR7_WDT
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tristate "TI AR7 Watchdog Timer"
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depends on AR7
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help
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Hardware driver for the TI AR7 Watchdog Timer.
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# PARISC Architecture
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# POWERPC Architecture
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@ -90,6 +90,7 @@ obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o
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obj-$(CONFIG_INDYDOG) += indydog.o
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obj-$(CONFIG_WDT_MTX1) += mtx-1_wdt.o
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obj-$(CONFIG_WDT_RM9K_GPI) += rm9k_wdt.o
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obj-$(CONFIG_AR7_WDT) += ar7_wdt.o
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# PARISC Architecture
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349
drivers/watchdog/ar7_wdt.c
Normal file
349
drivers/watchdog/ar7_wdt.c
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@ -0,0 +1,349 @@
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/*
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* drivers/watchdog/ar7_wdt.c
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*
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* Copyright (C) 2007 Nicolas Thill <nico@openwrt.org>
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* Copyright (c) 2005 Enrik Berkhan <Enrik.Berkhan@akk.org>
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*
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* Some code taken from:
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* National Semiconductor SCx200 Watchdog support
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* Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/notifier.h>
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#include <linux/reboot.h>
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#include <linux/fs.h>
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#include <linux/ioport.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#include <asm/addrspace.h>
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#include <asm/ar7/ar7.h>
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#define DRVNAME "ar7_wdt"
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#define LONGNAME "TI AR7 Watchdog Timer"
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MODULE_AUTHOR("Nicolas Thill <nico@openwrt.org>");
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MODULE_DESCRIPTION(LONGNAME);
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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static int margin = 60;
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module_param(margin, int, 0);
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MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
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static int nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, int, 0);
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MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
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#define READ_REG(x) readl((void __iomem *)&(x))
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#define WRITE_REG(x, v) writel((v), (void __iomem *)&(x))
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struct ar7_wdt {
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u32 kick_lock;
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u32 kick;
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u32 change_lock;
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u32 change;
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u32 disable_lock;
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u32 disable;
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u32 prescale_lock;
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u32 prescale;
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};
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static struct semaphore open_semaphore;
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static unsigned expect_close;
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/* XXX currently fixed, allows max margin ~68.72 secs */
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#define prescale_value 0xffff
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/* Offset of the WDT registers */
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static unsigned long ar7_regs_wdt;
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/* Pointer to the remapped WDT IO space */
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static struct ar7_wdt *ar7_wdt;
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static void ar7_wdt_get_regs(void)
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{
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u16 chip_id = ar7_chip_id();
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switch (chip_id) {
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case AR7_CHIP_7100:
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case AR7_CHIP_7200:
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ar7_regs_wdt = AR7_REGS_WDT;
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break;
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default:
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ar7_regs_wdt = UR8_REGS_WDT;
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break;
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}
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}
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static void ar7_wdt_kick(u32 value)
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{
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WRITE_REG(ar7_wdt->kick_lock, 0x5555);
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if ((READ_REG(ar7_wdt->kick_lock) & 3) == 1) {
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WRITE_REG(ar7_wdt->kick_lock, 0xaaaa);
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if ((READ_REG(ar7_wdt->kick_lock) & 3) == 3) {
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WRITE_REG(ar7_wdt->kick, value);
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return;
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}
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}
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printk(KERN_ERR DRVNAME ": failed to unlock WDT kick reg\n");
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}
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static void ar7_wdt_prescale(u32 value)
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{
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WRITE_REG(ar7_wdt->prescale_lock, 0x5a5a);
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if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 1) {
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WRITE_REG(ar7_wdt->prescale_lock, 0xa5a5);
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if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 3) {
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WRITE_REG(ar7_wdt->prescale, value);
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return;
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}
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}
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printk(KERN_ERR DRVNAME ": failed to unlock WDT prescale reg\n");
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}
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static void ar7_wdt_change(u32 value)
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{
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WRITE_REG(ar7_wdt->change_lock, 0x6666);
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if ((READ_REG(ar7_wdt->change_lock) & 3) == 1) {
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WRITE_REG(ar7_wdt->change_lock, 0xbbbb);
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if ((READ_REG(ar7_wdt->change_lock) & 3) == 3) {
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WRITE_REG(ar7_wdt->change, value);
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return;
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}
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}
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printk(KERN_ERR DRVNAME ": failed to unlock WDT change reg\n");
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}
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static void ar7_wdt_disable(u32 value)
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{
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WRITE_REG(ar7_wdt->disable_lock, 0x7777);
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if ((READ_REG(ar7_wdt->disable_lock) & 3) == 1) {
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WRITE_REG(ar7_wdt->disable_lock, 0xcccc);
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if ((READ_REG(ar7_wdt->disable_lock) & 3) == 2) {
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WRITE_REG(ar7_wdt->disable_lock, 0xdddd);
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if ((READ_REG(ar7_wdt->disable_lock) & 3) == 3) {
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WRITE_REG(ar7_wdt->disable, value);
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return;
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}
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}
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}
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printk(KERN_ERR DRVNAME ": failed to unlock WDT disable reg\n");
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}
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static void ar7_wdt_update_margin(int new_margin)
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{
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u32 change;
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change = new_margin * (ar7_vbus_freq() / prescale_value);
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if (change < 1) change = 1;
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if (change > 0xffff) change = 0xffff;
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ar7_wdt_change(change);
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margin = change * prescale_value / ar7_vbus_freq();
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printk(KERN_INFO DRVNAME
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": timer margin %d seconds (prescale %d, change %d, freq %d)\n",
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margin, prescale_value, change, ar7_vbus_freq());
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}
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static void ar7_wdt_enable_wdt(void)
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{
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printk(KERN_DEBUG DRVNAME ": enabling watchdog timer\n");
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ar7_wdt_disable(1);
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ar7_wdt_kick(1);
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}
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static void ar7_wdt_disable_wdt(void)
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{
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printk(KERN_DEBUG DRVNAME ": disabling watchdog timer\n");
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ar7_wdt_disable(0);
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}
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static int ar7_wdt_open(struct inode *inode, struct file *file)
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{
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/* only allow one at a time */
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if (down_trylock(&open_semaphore))
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return -EBUSY;
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ar7_wdt_enable_wdt();
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expect_close = 0;
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return nonseekable_open(inode, file);
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}
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static int ar7_wdt_release(struct inode *inode, struct file *file)
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{
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if (!expect_close)
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printk(KERN_WARNING DRVNAME
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": watchdog device closed unexpectedly,"
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"will not disable the watchdog timer\n");
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else if (!nowayout)
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ar7_wdt_disable_wdt();
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up(&open_semaphore);
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return 0;
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}
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static int ar7_wdt_notify_sys(struct notifier_block *this,
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unsigned long code, void *unused)
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{
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if (code == SYS_HALT || code == SYS_POWER_OFF)
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if (!nowayout)
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ar7_wdt_disable_wdt();
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return NOTIFY_DONE;
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}
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static struct notifier_block ar7_wdt_notifier = {
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.notifier_call = ar7_wdt_notify_sys
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};
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static ssize_t ar7_wdt_write(struct file *file, const char *data,
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size_t len, loff_t *ppos)
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{
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/* check for a magic close character */
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if (len) {
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size_t i;
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ar7_wdt_kick(1);
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expect_close = 0;
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for (i = 0; i < len; ++i) {
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char c;
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if (get_user(c, data+i))
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return -EFAULT;
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if (c == 'V')
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expect_close = 1;
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}
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}
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return len;
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}
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static int ar7_wdt_ioctl(struct inode *inode, struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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static struct watchdog_info ident = {
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.identity = LONGNAME,
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.firmware_version = 1,
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.options = (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING),
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};
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int new_margin;
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switch (cmd) {
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default:
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return -ENOTTY;
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case WDIOC_GETSUPPORT:
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if (copy_to_user((struct watchdog_info *)arg, &ident,
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sizeof(ident)))
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return -EFAULT;
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return 0;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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if (put_user(0, (int *)arg))
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return -EFAULT;
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return 0;
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case WDIOC_KEEPALIVE:
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ar7_wdt_kick(1);
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return 0;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_margin, (int *)arg))
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return -EFAULT;
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if (new_margin < 1)
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return -EINVAL;
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ar7_wdt_update_margin(new_margin);
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ar7_wdt_kick(1);
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case WDIOC_GETTIMEOUT:
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if (put_user(margin, (int *)arg))
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return -EFAULT;
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return 0;
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}
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}
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static struct file_operations ar7_wdt_fops = {
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.owner = THIS_MODULE,
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.write = ar7_wdt_write,
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.ioctl = ar7_wdt_ioctl,
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.open = ar7_wdt_open,
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.release = ar7_wdt_release,
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};
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static struct miscdevice ar7_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &ar7_wdt_fops,
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};
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static int __init ar7_wdt_init(void)
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{
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int rc;
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ar7_wdt_get_regs();
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if (!request_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt),
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LONGNAME)) {
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printk(KERN_WARNING DRVNAME ": watchdog I/O region busy\n");
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return -EBUSY;
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}
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ar7_wdt = (struct ar7_wdt *)
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ioremap(ar7_regs_wdt, sizeof(struct ar7_wdt));
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ar7_wdt_disable_wdt();
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ar7_wdt_prescale(prescale_value);
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ar7_wdt_update_margin(margin);
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sema_init(&open_semaphore, 1);
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rc = register_reboot_notifier(&ar7_wdt_notifier);
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if (rc) {
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printk(KERN_ERR DRVNAME
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": unable to register reboot notifier\n");
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goto out_alloc;
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}
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rc = misc_register(&ar7_wdt_miscdev);
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if (rc) {
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printk(KERN_ERR DRVNAME ": unable to register misc device\n");
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goto out_register;
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}
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goto out;
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out_register:
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unregister_reboot_notifier(&ar7_wdt_notifier);
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out_alloc:
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iounmap(ar7_wdt);
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release_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt));
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out:
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return rc;
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}
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static void __exit ar7_wdt_cleanup(void)
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{
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misc_deregister(&ar7_wdt_miscdev);
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unregister_reboot_notifier(&ar7_wdt_notifier);
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iounmap(ar7_wdt);
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release_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt));
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}
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module_init(ar7_wdt_init);
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module_exit(ar7_wdt_cleanup);
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