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[WATCHDOG] Blackfin on-chip watchdog driver
This patch implements the driver necessary use the Analog Devices Blackfin processor's on-chip watchdog controller, supports BF53[123]/BF53[467]/BF54[2489]/BF561. Signed-off-by: Mike Frysinger <michael.frysinger@analog.com> Signed-off-by: Bryan Wu <bryan.wu@analog.com> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
This commit is contained in:
Bryan Wu
Wim Van Sebroeck
parent
8cf18971ec
commit
1e6d320f40
@ -771,6 +771,14 @@ L: uclinux-dist-devel@blackfin.uclinux.org (subscribers-only)
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W: http://blackfin.uclinux.org
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S: Supported
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BLACKFIN WATCHDOG DRIVER
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P: Mike Frysinger
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M: michael.frysinger@analog.com
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M: vapier.adi@gmail.com
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L: uclinux-dist-devel@blackfin.uclinux.org (subscribers-only)
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W: http://blackfin.uclinux.org
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S: Supported
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BAYCOM/HDLCDRV DRIVERS FOR AX.25
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P: Thomas Sailer
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M: t.sailer@alumni.ethz.ch
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@ -212,6 +212,19 @@ config AT32AP700X_WDT
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Watchdog timer embedded into AT32AP700x devices. This will reboot
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your system when the timeout is reached.
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# Blackfin Architecture
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config BFIN_WDT
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tristate "Blackfin On-Chip Watchdog Timer"
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depends on WATCHDOG && BLACKFIN
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---help---
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If you say yes here you will get support for the Blackfin On-Chip
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Watchdog Timer. If you have one of these processors and wish to
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have watchdog support enabled, say Y, otherwise say N.
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To compile this driver as a module, choose M here: the
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module will be called bfin_wdt.
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# X86 (i386 + ia64 + x86_64) Architecture
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config ACQUIRE_WDT
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@ -40,6 +40,9 @@ obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o
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# AVR32 Architecture
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obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
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# Blackfin Architecture
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obj-$(CONFIG_BFIN_WDT) += bfin_wdt.o
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# X86 (i386 + ia64 + x86_64) Architecture
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obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
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obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o
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490
drivers/char/watchdog/bfin_wdt.c
Normal file
490
drivers/char/watchdog/bfin_wdt.c
Normal file
@ -0,0 +1,490 @@
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/*
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* Blackfin On-Chip Watchdog Driver
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* Supports BF53[123]/BF53[467]/BF54[2489]/BF561
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*
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* Originally based on softdog.c
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* Copyright 2006-2007 Analog Devices Inc.
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* Copyright 2006-2007 Michele d'Amico
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* Copyright 1996 Alan Cox <alan@redhat.com>
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*
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* Enter bugs at http://blackfin.uclinux.org/
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*
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* Licensed under the GPL-2 or later.
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*/
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#include <linux/platform_device.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/timer.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/notifier.h>
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#include <linux/reboot.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <asm/blackfin.h>
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#include <asm/uaccess.h>
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#define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args)
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#define stampit() stamp("here i am")
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#define WATCHDOG_NAME "bfin-wdt"
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#define PFX WATCHDOG_NAME ": "
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/* The BF561 has two watchdogs (one per core), but since Linux
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* only runs on core A, we'll just work with that one.
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*/
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#ifdef BF561_FAMILY
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# define bfin_read_WDOG_CTL() bfin_read_WDOGA_CTL()
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# define bfin_read_WDOG_CNT() bfin_read_WDOGA_CNT()
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# define bfin_read_WDOG_STAT() bfin_read_WDOGA_STAT()
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# define bfin_write_WDOG_CTL(x) bfin_write_WDOGA_CTL(x)
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# define bfin_write_WDOG_CNT(x) bfin_write_WDOGA_CNT(x)
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# define bfin_write_WDOG_STAT(x) bfin_write_WDOGA_STAT(x)
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#endif
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/* Bit in SWRST that indicates boot caused by watchdog */
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#define SWRST_RESET_WDOG 0x4000
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/* Bit in WDOG_CTL that indicates watchdog has expired (WDR0) */
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#define WDOG_EXPIRED 0x8000
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/* Masks for WDEV field in WDOG_CTL register */
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#define ICTL_RESET 0x0
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#define ICTL_NMI 0x2
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#define ICTL_GPI 0x4
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#define ICTL_NONE 0x6
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#define ICTL_MASK 0x6
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/* Masks for WDEN field in WDOG_CTL register */
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#define WDEN_MASK 0x0FF0
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#define WDEN_ENABLE 0x0000
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#define WDEN_DISABLE 0x0AD0
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/* some defaults */
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#define WATCHDOG_TIMEOUT 20
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static unsigned int timeout = WATCHDOG_TIMEOUT;
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static int nowayout = WATCHDOG_NOWAYOUT;
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static struct watchdog_info bfin_wdt_info;
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static unsigned long open_check;
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static char expect_close;
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static spinlock_t bfin_wdt_spinlock = SPIN_LOCK_UNLOCKED;
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/**
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* bfin_wdt_keepalive - Keep the Userspace Watchdog Alive
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*
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* The Userspace watchdog got a KeepAlive: schedule the next timeout.
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*/
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static int bfin_wdt_keepalive(void)
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{
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stampit();
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bfin_write_WDOG_STAT(0);
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return 0;
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}
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/**
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* bfin_wdt_stop - Stop the Watchdog
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*
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* Stops the on-chip watchdog.
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*/
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static int bfin_wdt_stop(void)
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{
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stampit();
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bfin_write_WDOG_CTL(WDEN_DISABLE);
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return 0;
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}
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/**
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* bfin_wdt_start - Start the Watchdog
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*
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* Starts the on-chip watchdog. Automatically loads WDOG_CNT
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* into WDOG_STAT for us.
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*/
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static int bfin_wdt_start(void)
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{
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stampit();
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bfin_write_WDOG_CTL(WDEN_ENABLE | ICTL_RESET);
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return 0;
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}
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/**
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* bfin_wdt_running - Check Watchdog status
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*
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* See if the watchdog is running.
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*/
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static int bfin_wdt_running(void)
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{
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stampit();
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return ((bfin_read_WDOG_CTL() & WDEN_MASK) != WDEN_DISABLE);
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}
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/**
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* bfin_wdt_set_timeout - Set the Userspace Watchdog timeout
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* @t: new timeout value (in seconds)
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*
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* Translate the specified timeout in seconds into System Clock
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* terms which is what the on-chip Watchdog requires.
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*/
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static int bfin_wdt_set_timeout(unsigned long t)
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{
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u32 cnt;
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unsigned long flags;
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stampit();
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cnt = t * get_sclk();
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if (cnt < get_sclk()) {
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printk(KERN_WARNING PFX "timeout value is too large\n");
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return -EINVAL;
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}
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spin_lock_irqsave(&bfin_wdt_spinlock, flags);
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{
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int run = bfin_wdt_running();
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bfin_wdt_stop();
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bfin_write_WDOG_CNT(cnt);
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if (run) bfin_wdt_start();
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}
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spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
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timeout = t;
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return 0;
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}
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/**
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* bfin_wdt_open - Open the Device
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* @inode: inode of device
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* @file: file handle of device
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*
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* Watchdog device is opened and started.
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*/
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static int bfin_wdt_open(struct inode *inode, struct file *file)
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{
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stampit();
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if (test_and_set_bit(0, &open_check))
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return -EBUSY;
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if (nowayout)
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__module_get(THIS_MODULE);
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bfin_wdt_keepalive();
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bfin_wdt_start();
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return nonseekable_open(inode, file);
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}
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/**
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* bfin_wdt_close - Close the Device
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* @inode: inode of device
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* @file: file handle of device
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*
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* Watchdog device is closed and stopped.
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*/
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static int bfin_wdt_release(struct inode *inode, struct file *file)
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{
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stampit();
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if (expect_close == 42) {
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bfin_wdt_stop();
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} else {
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printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
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bfin_wdt_keepalive();
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}
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expect_close = 0;
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clear_bit(0, &open_check);
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return 0;
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}
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/**
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* bfin_wdt_write - Write to Device
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* @file: file handle of device
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* @buf: buffer to write
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* @count: length of buffer
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* @ppos: offset
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*
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* Pings the watchdog on write.
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*/
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static ssize_t bfin_wdt_write(struct file *file, const char __user *data,
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size_t len, loff_t *ppos)
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{
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stampit();
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if (len) {
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if (!nowayout) {
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size_t i;
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/* In case it was set long ago */
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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 = 42;
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}
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}
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bfin_wdt_keepalive();
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}
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return len;
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}
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/**
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* bfin_wdt_ioctl - Query Device
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* @inode: inode of device
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* @file: file handle of device
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* @cmd: watchdog command
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* @arg: argument
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*
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* Query basic information from the device or ping it, as outlined by the
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* watchdog API.
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*/
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static int bfin_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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void __user *argp = (void __user *)arg;
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int __user *p = argp;
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stampit();
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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(argp, &bfin_wdt_info, sizeof(bfin_wdt_info)))
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return -EFAULT;
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else
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return 0;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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return put_user(!!(_bfin_swrst & SWRST_RESET_WDOG), p);
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case WDIOC_KEEPALIVE:
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bfin_wdt_keepalive();
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return 0;
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case WDIOC_SETTIMEOUT: {
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int new_timeout;
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if (get_user(new_timeout, p))
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return -EFAULT;
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if (bfin_wdt_set_timeout(new_timeout))
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return -EINVAL;
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}
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/* Fall */
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case WDIOC_GETTIMEOUT:
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return put_user(timeout, p);
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case WDIOC_SETOPTIONS: {
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unsigned long flags;
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int options, ret = -EINVAL;
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if (get_user(options, p))
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return -EFAULT;
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spin_lock_irqsave(&bfin_wdt_spinlock, flags);
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if (options & WDIOS_DISABLECARD) {
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bfin_wdt_stop();
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ret = 0;
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}
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if (options & WDIOS_ENABLECARD) {
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bfin_wdt_start();
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ret = 0;
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}
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spin_unlock_irqrestore(&bfin_wdt_spinlock, flags);
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return ret;
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}
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}
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}
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/**
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* bfin_wdt_notify_sys - Notifier Handler
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* @this: notifier block
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* @code: notifier event
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* @unused: unused
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*
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* Handles specific events, such as turning off the watchdog during a
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* shutdown event.
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*/
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static int bfin_wdt_notify_sys(struct notifier_block *this, unsigned long code,
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void *unused)
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{
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stampit();
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if (code == SYS_DOWN || code == SYS_HALT)
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bfin_wdt_stop();
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return NOTIFY_DONE;
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}
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#ifdef CONFIG_PM
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static int state_before_suspend;
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/**
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* bfin_wdt_suspend - suspend the watchdog
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* @pdev: device being suspended
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* @state: requested suspend state
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*
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* Remember if the watchdog was running and stop it.
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* TODO: is this even right? Doesn't seem to be any
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* standard in the watchdog world ...
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*/
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static int bfin_wdt_suspend(struct platform_device *pdev, pm_message_t state)
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{
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stampit();
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state_before_suspend = bfin_wdt_running();
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bfin_wdt_stop();
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return 0;
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}
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/**
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* bfin_wdt_resume - resume the watchdog
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* @pdev: device being resumed
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*
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* If the watchdog was running, turn it back on.
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*/
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static int bfin_wdt_resume(struct platform_device *pdev)
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{
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stampit();
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if (state_before_suspend) {
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bfin_wdt_set_timeout(timeout);
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bfin_wdt_start();
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}
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return 0;
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}
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#else
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# define bfin_wdt_suspend NULL
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# define bfin_wdt_resume NULL
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#endif
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static struct platform_device bfin_wdt_device = {
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.name = WATCHDOG_NAME,
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.id = -1,
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};
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static struct platform_driver bfin_wdt_driver = {
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.driver = {
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.name = WATCHDOG_NAME,
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.owner = THIS_MODULE,
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},
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.suspend = bfin_wdt_suspend,
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.resume = bfin_wdt_resume,
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};
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static struct file_operations bfin_wdt_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = bfin_wdt_write,
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.ioctl = bfin_wdt_ioctl,
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.open = bfin_wdt_open,
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.release = bfin_wdt_release,
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};
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static struct miscdevice bfin_wdt_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &bfin_wdt_fops,
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};
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static struct watchdog_info bfin_wdt_info = {
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.identity = "Blackfin Watchdog",
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.options = WDIOF_SETTIMEOUT |
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WDIOF_KEEPALIVEPING |
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WDIOF_MAGICCLOSE,
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};
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static struct notifier_block bfin_wdt_notifier = {
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.notifier_call = bfin_wdt_notify_sys,
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};
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/**
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* bfin_wdt_init - Initialize module
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*
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* Registers the device and notifier handler. Actual device
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* initialization is handled by bfin_wdt_open().
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*/
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static int __init bfin_wdt_init(void)
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{
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int ret;
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stampit();
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/* Check that the timeout value is within range */
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if (bfin_wdt_set_timeout(timeout))
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return -EINVAL;
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/* Since this is an on-chip device and needs no board-specific
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* resources, we'll handle all the platform device stuff here.
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*/
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ret = platform_device_register(&bfin_wdt_device);
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if (ret)
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return ret;
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ret = platform_driver_probe(&bfin_wdt_driver, NULL);
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if (ret)
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return ret;
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ret = register_reboot_notifier(&bfin_wdt_notifier);
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if (ret) {
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printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", ret);
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return ret;
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}
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ret = misc_register(&bfin_wdt_miscdev);
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if (ret) {
|
||||
printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
|
||||
WATCHDOG_MINOR, ret);
|
||||
unregister_reboot_notifier(&bfin_wdt_notifier);
|
||||
return ret;
|
||||
}
|
||||
|
||||
printk(KERN_INFO PFX "initialized: timeout=%d sec (nowayout=%d)\n",
|
||||
timeout, nowayout);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* bfin_wdt_exit - Deinitialize module
|
||||
*
|
||||
* Unregisters the device and notifier handler. Actual device
|
||||
* deinitialization is handled by bfin_wdt_close().
|
||||
*/
|
||||
static void __exit bfin_wdt_exit(void)
|
||||
{
|
||||
misc_deregister(&bfin_wdt_miscdev);
|
||||
unregister_reboot_notifier(&bfin_wdt_notifier);
|
||||
}
|
||||
|
||||
module_init(bfin_wdt_init);
|
||||
module_exit(bfin_wdt_exit);
|
||||
|
||||
MODULE_AUTHOR("Michele d'Amico, Mike Frysinger <vapier@gentoo.org>");
|
||||
MODULE_DESCRIPTION("Blackfin Watchdog Device Driver");
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
||||
|
||||
module_param(timeout, uint, 0);
|
||||
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
|
||||
|
||||
module_param(nowayout, int, 0);
|
||||
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
||||
Loading…
Reference in New Issue
Block a user