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linux-next/drivers/watchdog/sbc_fitpc2_wdt.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

268 lines
5.3 KiB
C

/*
* Watchdog driver for SBC-FITPC2 board
*
* Author: Denis Turischev <denis@compulab.co.il>
*
* Adapted from the IXP2000 watchdog driver by Deepak Saxena.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#define pr_fmt(fmt) KBUILD_MODNAME " WATCHDOG: " fmt
#include <linux/module.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/moduleparam.h>
#include <linux/dmi.h>
#include <linux/io.h>
#include <linux/uaccess.h>
static bool nowayout = WATCHDOG_NOWAYOUT;
static unsigned int margin = 60; /* (secs) Default is 1 minute */
static unsigned long wdt_status;
static DEFINE_MUTEX(wdt_lock);
#define WDT_IN_USE 0
#define WDT_OK_TO_CLOSE 1
#define COMMAND_PORT 0x4c
#define DATA_PORT 0x48
#define IFACE_ON_COMMAND 1
#define REBOOT_COMMAND 2
#define WATCHDOG_NAME "SBC-FITPC2 Watchdog"
static void wdt_send_data(unsigned char command, unsigned char data)
{
outb(data, DATA_PORT);
msleep(200);
outb(command, COMMAND_PORT);
msleep(100);
}
static void wdt_enable(void)
{
mutex_lock(&wdt_lock);
wdt_send_data(IFACE_ON_COMMAND, 1);
wdt_send_data(REBOOT_COMMAND, margin);
mutex_unlock(&wdt_lock);
}
static void wdt_disable(void)
{
mutex_lock(&wdt_lock);
wdt_send_data(IFACE_ON_COMMAND, 0);
wdt_send_data(REBOOT_COMMAND, 0);
mutex_unlock(&wdt_lock);
}
static int fitpc2_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(WDT_IN_USE, &wdt_status))
return -EBUSY;
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
wdt_enable();
return nonseekable_open(inode, file);
}
static ssize_t fitpc2_wdt_write(struct file *file, const char *data,
size_t len, loff_t *ppos)
{
size_t i;
if (!len)
return 0;
if (nowayout) {
len = 0;
goto out;
}
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
set_bit(WDT_OK_TO_CLOSE, &wdt_status);
}
out:
wdt_enable();
return len;
}
static const struct watchdog_info ident = {
.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING,
.identity = WATCHDOG_NAME,
};
static long fitpc2_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int ret = -ENOTTY;
int time;
switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user((struct watchdog_info *)arg, &ident,
sizeof(ident)) ? -EFAULT : 0;
break;
case WDIOC_GETSTATUS:
ret = put_user(0, (int *)arg);
break;
case WDIOC_GETBOOTSTATUS:
ret = put_user(0, (int *)arg);
break;
case WDIOC_KEEPALIVE:
wdt_enable();
ret = 0;
break;
case WDIOC_SETTIMEOUT:
ret = get_user(time, (int *)arg);
if (ret)
break;
if (time < 31 || time > 255) {
ret = -EINVAL;
break;
}
margin = time;
wdt_enable();
/* Fall through */
case WDIOC_GETTIMEOUT:
ret = put_user(margin, (int *)arg);
break;
}
return ret;
}
static int fitpc2_wdt_release(struct inode *inode, struct file *file)
{
if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
wdt_disable();
pr_info("Device disabled\n");
} else {
pr_warn("Device closed unexpectedly - timer will not stop\n");
wdt_enable();
}
clear_bit(WDT_IN_USE, &wdt_status);
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
return 0;
}
static const struct file_operations fitpc2_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = fitpc2_wdt_write,
.unlocked_ioctl = fitpc2_wdt_ioctl,
.open = fitpc2_wdt_open,
.release = fitpc2_wdt_release,
};
static struct miscdevice fitpc2_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &fitpc2_wdt_fops,
};
static int __init fitpc2_wdt_init(void)
{
int err;
const char *brd_name;
brd_name = dmi_get_system_info(DMI_BOARD_NAME);
if (!brd_name || !strstr(brd_name, "SBC-FITPC2"))
return -ENODEV;
pr_info("%s found\n", brd_name);
if (!request_region(COMMAND_PORT, 1, WATCHDOG_NAME)) {
pr_err("I/O address 0x%04x already in use\n", COMMAND_PORT);
return -EIO;
}
if (!request_region(DATA_PORT, 1, WATCHDOG_NAME)) {
pr_err("I/O address 0x%04x already in use\n", DATA_PORT);
err = -EIO;
goto err_data_port;
}
if (margin < 31 || margin > 255) {
pr_err("margin must be in range 31 - 255 seconds, you tried to set %d\n",
margin);
err = -EINVAL;
goto err_margin;
}
err = misc_register(&fitpc2_wdt_miscdev);
if (err) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, err);
goto err_margin;
}
return 0;
err_margin:
release_region(DATA_PORT, 1);
err_data_port:
release_region(COMMAND_PORT, 1);
return err;
}
static void __exit fitpc2_wdt_exit(void)
{
misc_deregister(&fitpc2_wdt_miscdev);
release_region(DATA_PORT, 1);
release_region(COMMAND_PORT, 1);
}
module_init(fitpc2_wdt_init);
module_exit(fitpc2_wdt_exit);
MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>");
MODULE_DESCRIPTION("SBC-FITPC2 Watchdog");
module_param(margin, int, 0);
MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);