forked from luck/tmp_suning_uos_patched
fb8f7ba077
It seems that some watchdog drivers are doing following mistake:
rv = misc_register();
if (rv < 0)
return rv;
rv = request_region();
if (rv < 0) {
misc_deregister();
return rv;
}
But, right after misc_register() returns, misc device can be opened and
ioctls interacting with hardware issued, and driver can do outb() to
port it doesn't own yet, because request_region() is still pending.
Here is my patch, compile-tested only.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
469 lines
11 KiB
C
469 lines
11 KiB
C
/*
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* Eurotech CPU-1220/1410 on board WDT driver
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*
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* (c) Copyright 2001 Ascensit <support@ascensit.com>
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* (c) Copyright 2001 Rodolfo Giometti <giometti@ascensit.com>
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* (c) Copyright 2002 Rob Radez <rob@osinvestor.com>
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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 <alan@redhat.com>, All Rights Reserved.
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* http://www.redhat.com
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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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 <alan@lxorguk.ukuu.org.uk>*
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*/
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/* Changelog:
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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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* 2001 - Rodolfo Giometti
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* Initial release
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*
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* 2002.05.30 - Joel Becker <joel.becker@oracle.com>
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* Added Matt Domsch's nowayout module option.
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*/
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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 <asm/io.h>
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#include <asm/uaccess.h>
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#include <asm/system.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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/*
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* You must set these - there is no sane way to probe for this board.
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* You can use eurwdt=x,y to set these now.
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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 int nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, int, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __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(io, int, 0);
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MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)");
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module_param(irq, int, 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, !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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printk(KERN_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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printk(KERN_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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printk(KERN_CRIT "timeout WDT timeout\n");
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#ifdef ONLY_TESTING
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printk(KERN_CRIT "Would Reboot.\n");
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#else
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printk(KERN_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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eurwdt_ping(); /* the default timeout */
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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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* @inode: inode of the device
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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 int eurwdt_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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static struct watchdog_info ident = {
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.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | 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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default:
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return -ENOTTY;
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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_KEEPALIVE:
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eurwdt_ping();
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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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eurwdt_timeout = time;
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eurwdt_set_timeout(time);
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/* Fall */
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case WDIOC_GETTIMEOUT:
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return put_user(eurwdt_timeout, 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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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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return retval;
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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 nonseekable_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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printk(KERN_CRIT "eurwdt: 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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/* Turn the card off */
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eurwdt_disable_timer();
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}
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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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.ioctl = eurwdt_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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* cleanup_module:
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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, IRQF_DISABLED, "eurwdt", NULL);
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if(ret) {
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printk(KERN_ERR "eurwdt: 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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printk(KERN_ERR "eurwdt: 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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printk(KERN_ERR "eurwdt: 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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printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",
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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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printk(KERN_INFO "Eurotech WDT driver 0.01 at %X (Interrupt %d)"
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" - 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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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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