linux/drivers/watchdog/advantechwdt.c
Linus Torvalds 0195c00244 Disintegrate and delete asm/system.h
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Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...
2012-03-28 15:58:21 -07:00

349 lines
7.9 KiB
C

/*
* Advantech Single Board Computer WDT driver
*
* (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
*
* Based on acquirewdt.c which is based on wdt.c.
* Original copyright messages:
*
* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
* warranty for any of this software. This material is provided
* "AS-IS" and at no charge.
*
* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
*
* 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
* Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
*
* 16-Oct-2002 Rob Radez <rob@osinvestor.com>
* Clean up ioctls, clean up init + exit, add expect close support,
* add wdt_start and wdt_stop as parameters.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#define DRV_NAME "advantechwdt"
#define WATCHDOG_NAME "Advantech WDT"
#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
/* the watchdog platform device */
static struct platform_device *advwdt_platform_device;
static unsigned long advwdt_is_open;
static char adv_expect_close;
/*
* You must set these - there is no sane way to probe for this board.
*
* To enable or restart, write the timeout value in seconds (1 to 63)
* to I/O port wdt_start. To disable, read I/O port wdt_stop.
* Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
* check your manual (at least the PCA-6159 seems to be different -
* the manual says wdt_stop is 0x43, not 0x443).
* (0x43 is also a write-only control register for the 8254 timer!)
*/
static int wdt_stop = 0x443;
module_param(wdt_stop, int, 0);
MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
static int wdt_start = 0x443;
module_param(wdt_start, int, 0);
MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout,
"Watchdog timeout in seconds. 1<= timeout <=63, default="
__MODULE_STRING(WATCHDOG_TIMEOUT) ".");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
/*
* Watchdog Operations
*/
static void advwdt_ping(void)
{
/* Write a watchdog value */
outb_p(timeout, wdt_start);
}
static void advwdt_disable(void)
{
inb_p(wdt_stop);
}
static int advwdt_set_heartbeat(int t)
{
if (t < 1 || t > 63)
return -EINVAL;
timeout = t;
return 0;
}
/*
* /dev/watchdog handling
*/
static ssize_t advwdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (count) {
if (!nowayout) {
size_t i;
adv_expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
adv_expect_close = 42;
}
}
advwdt_ping();
}
return count;
}
static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int new_timeout;
void __user *argp = (void __user *)arg;
int __user *p = argp;
static const struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING |
WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = WATCHDOG_NAME,
};
switch (cmd) {
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_SETOPTIONS:
{
int options, retval = -EINVAL;
if (get_user(options, p))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
advwdt_disable();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
advwdt_ping();
retval = 0;
}
return retval;
}
case WDIOC_KEEPALIVE:
advwdt_ping();
break;
case WDIOC_SETTIMEOUT:
if (get_user(new_timeout, p))
return -EFAULT;
if (advwdt_set_heartbeat(new_timeout))
return -EINVAL;
advwdt_ping();
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(timeout, p);
default:
return -ENOTTY;
}
return 0;
}
static int advwdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &advwdt_is_open))
return -EBUSY;
/*
* Activate
*/
advwdt_ping();
return nonseekable_open(inode, file);
}
static int advwdt_close(struct inode *inode, struct file *file)
{
if (adv_expect_close == 42) {
advwdt_disable();
} else {
pr_crit("Unexpected close, not stopping watchdog!\n");
advwdt_ping();
}
clear_bit(0, &advwdt_is_open);
adv_expect_close = 0;
return 0;
}
/*
* Kernel Interfaces
*/
static const struct file_operations advwdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = advwdt_write,
.unlocked_ioctl = advwdt_ioctl,
.open = advwdt_open,
.release = advwdt_close,
};
static struct miscdevice advwdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &advwdt_fops,
};
/*
* Init & exit routines
*/
static int __devinit advwdt_probe(struct platform_device *dev)
{
int ret;
if (wdt_stop != wdt_start) {
if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
pr_err("I/O address 0x%04x already in use\n",
wdt_stop);
ret = -EIO;
goto out;
}
}
if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
pr_err("I/O address 0x%04x already in use\n", wdt_start);
ret = -EIO;
goto unreg_stop;
}
/* Check that the heartbeat value is within it's range ;
* if not reset to the default */
if (advwdt_set_heartbeat(timeout)) {
advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
pr_info("timeout value must be 1<=x<=63, using %d\n", timeout);
}
ret = misc_register(&advwdt_miscdev);
if (ret != 0) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
goto unreg_regions;
}
pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
timeout, nowayout);
out:
return ret;
unreg_regions:
release_region(wdt_start, 1);
unreg_stop:
if (wdt_stop != wdt_start)
release_region(wdt_stop, 1);
goto out;
}
static int __devexit advwdt_remove(struct platform_device *dev)
{
misc_deregister(&advwdt_miscdev);
release_region(wdt_start, 1);
if (wdt_stop != wdt_start)
release_region(wdt_stop, 1);
return 0;
}
static void advwdt_shutdown(struct platform_device *dev)
{
/* Turn the WDT off if we have a soft shutdown */
advwdt_disable();
}
static struct platform_driver advwdt_driver = {
.probe = advwdt_probe,
.remove = __devexit_p(advwdt_remove),
.shutdown = advwdt_shutdown,
.driver = {
.owner = THIS_MODULE,
.name = DRV_NAME,
},
};
static int __init advwdt_init(void)
{
int err;
pr_info("WDT driver for Advantech single board computer initialising\n");
err = platform_driver_register(&advwdt_driver);
if (err)
return err;
advwdt_platform_device = platform_device_register_simple(DRV_NAME,
-1, NULL, 0);
if (IS_ERR(advwdt_platform_device)) {
err = PTR_ERR(advwdt_platform_device);
goto unreg_platform_driver;
}
return 0;
unreg_platform_driver:
platform_driver_unregister(&advwdt_driver);
return err;
}
static void __exit advwdt_exit(void)
{
platform_device_unregister(advwdt_platform_device);
platform_driver_unregister(&advwdt_driver);
pr_info("Watchdog Module Unloaded\n");
}
module_init(advwdt_init);
module_exit(advwdt_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);