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linux/drivers/watchdog/pc87413_wdt.c
Alexey Dobriyan c7dfd0cca3 [WATCHDOG] spin_lock_init() fixes 
Some watchdog drivers initialize global spinlocks in module's init function
which is tolerable, but some do it in PCI probe function.  So, switch to
static initialization to fix theoretical bugs and, more importantly, stop
giving people bad examples.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-11-02 19:09:07 +00:00

633 lines
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/*
* NS pc87413-wdt Watchdog Timer driver for Linux 2.6.x.x
*
* This code is based on wdt.c with original copyright.
*
* (C) Copyright 2006 Sven Anders, <anders@anduras.de>
* and Marcus Junker, <junker@anduras.de>
*
* 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 Sven Anders, Marcus Junker nor ANDURAS AG
* admit liability nor provide warranty for any of this software.
* This material is provided "AS-IS" and at no charge.
*
* Release 1.1
*/
#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/notifier.h>
#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/moduleparam.h>
#include <linux/version.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
/* #define DEBUG 1 */
#define DEFAULT_TIMEOUT 1 /* 1 minute */
#define MAX_TIMEOUT 255
#define VERSION "1.1"
#define MODNAME "pc87413 WDT"
#define PFX MODNAME ": "
#define DPFX MODNAME " - DEBUG: "
#define WDT_INDEX_IO_PORT (io+0) /* I/O port base (index register) */
#define WDT_DATA_IO_PORT (WDT_INDEX_IO_PORT+1)
#define SWC_LDN 0x04
#define SIOCFG2 0x22 /* Serial IO register */
#define WDCTL 0x10 /* Watchdog-Timer-Controll-Register */
#define WDTO 0x11 /* Watchdog timeout register */
#define WDCFG 0x12 /* Watchdog config register */
static int io = 0x2E; /* Address used on Portwell Boards */
static int timeout = DEFAULT_TIMEOUT; /* timeout value */
static unsigned long timer_enabled = 0; /* is the timer enabled? */
static char expect_close; /* is the close expected? */
static DEFINE_SPINLOCK(io_lock);/* to guard the watchdog from io races */
static int nowayout = WATCHDOG_NOWAYOUT;
/* -- Low level function ----------------------------------------*/
/* Select pins for Watchdog output */
static inline void pc87413_select_wdt_out (void)
{
unsigned int cr_data = 0;
/* Step 1: Select multiple pin,pin55,as WDT output */
outb_p(SIOCFG2, WDT_INDEX_IO_PORT);
cr_data = inb (WDT_DATA_IO_PORT);
cr_data |= 0x80; /* Set Bit7 to 1*/
outb_p(SIOCFG2, WDT_INDEX_IO_PORT);
outb_p(cr_data, WDT_DATA_IO_PORT);
#ifdef DEBUG
printk(KERN_INFO DPFX "Select multiple pin,pin55,as WDT output:"
" Bit7 to 1: %d\n", cr_data);
#endif
}
/* Enable SWC functions */
static inline void pc87413_enable_swc(void)
{
unsigned int cr_data=0;
/* Step 2: Enable SWC functions */
outb_p(0x07, WDT_INDEX_IO_PORT); /* Point SWC_LDN (LDN=4) */
outb_p(SWC_LDN, WDT_DATA_IO_PORT);
outb_p(0x30, WDT_INDEX_IO_PORT); /* Read Index 0x30 First */
cr_data = inb(WDT_DATA_IO_PORT);
cr_data |= 0x01; /* Set Bit0 to 1 */
outb_p(0x30, WDT_INDEX_IO_PORT);
outb_p(cr_data, WDT_DATA_IO_PORT); /* Index0x30_bit0P1 */
#ifdef DEBUG
printk(KERN_INFO DPFX "pc87413 - Enable SWC functions\n");
#endif
}
/* Read SWC I/O base address */
static inline unsigned int pc87413_get_swc_base(void)
{
unsigned int swc_base_addr = 0;
unsigned char addr_l, addr_h = 0;
/* Step 3: Read SWC I/O Base Address */
outb_p(0x60, WDT_INDEX_IO_PORT); /* Read Index 0x60 */
addr_h = inb(WDT_DATA_IO_PORT);
outb_p(0x61, WDT_INDEX_IO_PORT); /* Read Index 0x61 */
addr_l = inb(WDT_DATA_IO_PORT);
swc_base_addr = (addr_h << 8) + addr_l;
#ifdef DEBUG
printk(KERN_INFO DPFX "Read SWC I/O Base Address: low %d, high %d,"
" res %d\n", addr_l, addr_h, swc_base_addr);
#endif
return swc_base_addr;
}
/* Select Bank 3 of SWC */
static inline void pc87413_swc_bank3(unsigned int swc_base_addr)
{
/* Step 4: Select Bank3 of SWC */
outb_p(inb(swc_base_addr + 0x0f) | 0x03, swc_base_addr + 0x0f);
#ifdef DEBUG
printk(KERN_INFO DPFX "Select Bank3 of SWC\n");
#endif
}
/* Set watchdog timeout to x minutes */
static inline void pc87413_programm_wdto(unsigned int swc_base_addr,
char pc87413_time)
{
/* Step 5: Programm WDTO, Twd. */
outb_p(pc87413_time, swc_base_addr + WDTO);
#ifdef DEBUG
printk(KERN_INFO DPFX "Set WDTO to %d minutes\n", pc87413_time);
#endif
}
/* Enable WDEN */
static inline void pc87413_enable_wden(unsigned int swc_base_addr)
{
/* Step 6: Enable WDEN */
outb_p(inb (swc_base_addr + WDCTL) | 0x01, swc_base_addr + WDCTL);
#ifdef DEBUG
printk(KERN_INFO DPFX "Enable WDEN\n");
#endif
}
/* Enable SW_WD_TREN */
static inline void pc87413_enable_sw_wd_tren(unsigned int swc_base_addr)
{
/* Enable SW_WD_TREN */
outb_p(inb (swc_base_addr + WDCFG) | 0x80, swc_base_addr + WDCFG);
#ifdef DEBUG
printk(KERN_INFO DPFX "Enable SW_WD_TREN\n");
#endif
}
/* Disable SW_WD_TREN */
static inline void pc87413_disable_sw_wd_tren(unsigned int swc_base_addr)
{
/* Disable SW_WD_TREN */
outb_p(inb (swc_base_addr + WDCFG) & 0x7f, swc_base_addr + WDCFG);
#ifdef DEBUG
printk(KERN_INFO DPFX "pc87413 - Disable SW_WD_TREN\n");
#endif
}
/* Enable SW_WD_TRG */
static inline void pc87413_enable_sw_wd_trg(unsigned int swc_base_addr)
{
/* Enable SW_WD_TRG */
outb_p(inb (swc_base_addr + WDCTL) | 0x80, swc_base_addr + WDCTL);
#ifdef DEBUG
printk(KERN_INFO DPFX "pc87413 - Enable SW_WD_TRG\n");
#endif
}
/* Disable SW_WD_TRG */
static inline void pc87413_disable_sw_wd_trg(unsigned int swc_base_addr)
{
/* Disable SW_WD_TRG */
outb_p(inb (swc_base_addr + WDCTL) & 0x7f, swc_base_addr + WDCTL);
#ifdef DEBUG
printk(KERN_INFO DPFX "Disable SW_WD_TRG\n");
#endif
}
/* -- Higher level functions ------------------------------------*/
/* Enable the watchdog */
static void pc87413_enable(void)
{
unsigned int swc_base_addr;
spin_lock(&io_lock);
pc87413_select_wdt_out();
pc87413_enable_swc();
swc_base_addr = pc87413_get_swc_base();
pc87413_swc_bank3(swc_base_addr);
pc87413_programm_wdto(swc_base_addr, timeout);
pc87413_enable_wden(swc_base_addr);
pc87413_enable_sw_wd_tren(swc_base_addr);
pc87413_enable_sw_wd_trg(swc_base_addr);
spin_unlock(&io_lock);
}
/* Disable the watchdog */
static void pc87413_disable(void)
{
unsigned int swc_base_addr;
spin_lock(&io_lock);
pc87413_select_wdt_out();
pc87413_enable_swc();
swc_base_addr = pc87413_get_swc_base();
pc87413_swc_bank3(swc_base_addr);
pc87413_disable_sw_wd_tren(swc_base_addr);
pc87413_disable_sw_wd_trg(swc_base_addr);
pc87413_programm_wdto(swc_base_addr, 0);
spin_unlock(&io_lock);
}
/* Refresh the watchdog */
static void pc87413_refresh(void)
{
unsigned int swc_base_addr;
spin_lock(&io_lock);
pc87413_select_wdt_out();
pc87413_enable_swc();
swc_base_addr = pc87413_get_swc_base();
pc87413_swc_bank3(swc_base_addr);
pc87413_disable_sw_wd_tren(swc_base_addr);
pc87413_disable_sw_wd_trg(swc_base_addr);
pc87413_programm_wdto(swc_base_addr, timeout);
pc87413_enable_wden(swc_base_addr);
pc87413_enable_sw_wd_tren(swc_base_addr);
pc87413_enable_sw_wd_trg(swc_base_addr);
spin_unlock(&io_lock);
}
/* -- File operations -------------------------------------------*/
/**
* pc87413_open:
* @inode: inode of device
* @file: file handle to device
*
*/
static int pc87413_open(struct inode *inode, struct file *file)
{
/* /dev/watchdog can only be opened once */
if (test_and_set_bit(0, &timer_enabled))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
/* Reload and activate timer */
pc87413_refresh();
printk(KERN_INFO MODNAME "Watchdog enabled. Timeout set to"
" %d minute(s).\n", timeout);
return nonseekable_open(inode, file);
}
/**
* pc87413_release:
* @inode: inode to board
* @file: file handle to board
*
* The watchdog has a configurable API. There is a religious dispute
* between people who want their watchdog to be able to shut down and
* those who want to be sure if the watchdog manager dies the machine
* reboots. In the former case we disable the counters, in the latter
* case you have to open it again very soon.
*/
static int pc87413_release(struct inode *inode, struct file *file)
{
/* Shut off the timer. */
if (expect_close == 42) {
pc87413_disable();
printk(KERN_INFO MODNAME "Watchdog disabled,"
" sleeping again...\n");
} else {
printk(KERN_CRIT MODNAME "Unexpected close, not stopping"
" watchdog!\n");
pc87413_refresh();
}
clear_bit(0, &timer_enabled);
expect_close = 0;
return 0;
}
/**
* pc87413_status:
*
* return, if the watchdog is enabled (timeout is set...)
*/
static int pc87413_status(void)
{
return 0; /* currently not supported */
}
/**
* pc87413_write:
* @file: file handle to the watchdog
* @data: data buffer to write
* @len: length in bytes
* @ppos: pointer to the position to write. No seeks allowed
*
* A write to a watchdog device is defined as a keepalive signal. Any
* write of data will do, as we we don't define content meaning.
*/
static ssize_t pc87413_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
/* See if we got the magic character 'V' and reload the timer */
if (len) {
if (!nowayout) {
size_t i;
/* reset expect flag */
expect_close = 0;
/* scan to see whether or not we got the magic character */
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data+i))
return -EFAULT;
if (c == 'V')
expect_close = 42;
}
}
/* someone wrote to us, we should reload the timer */
pc87413_refresh();
}
return len;
}
/**
* pc87413_ioctl:
* @inode: inode of the device
* @file: file handle to the device
* @cmd: watchdog command
* @arg: argument pointer
*
* The watchdog API defines a common set of functions for all watchdogs
* according to their available features. We only actually usefully support
* querying capabilities and current status.
*/
static int pc87413_ioctl(struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
int new_timeout;
union {
struct watchdog_info __user *ident;
int __user *i;
} uarg;
static struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING |
WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "PC87413(HF/F) watchdog"
};
uarg.i = (int __user *)arg;
switch(cmd) {
default:
return -ENOTTY;
case WDIOC_GETSUPPORT:
return copy_to_user(uarg.ident, &ident,
sizeof(ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
return put_user(pc87413_status(), uarg.i);
case WDIOC_GETBOOTSTATUS:
return put_user(0, uarg.i);
case WDIOC_KEEPALIVE:
pc87413_refresh();
#ifdef DEBUG
printk(KERN_INFO DPFX "keepalive\n");
#endif
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_timeout, uarg.i))
return -EFAULT;
// the API states this is given in secs
new_timeout /= 60;
if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
return -EINVAL;
timeout = new_timeout;
pc87413_refresh();
// fall through and return the new timeout...
case WDIOC_GETTIMEOUT:
new_timeout = timeout * 60;
return put_user(new_timeout, uarg.i);
case WDIOC_SETOPTIONS:
{
int options, retval = -EINVAL;
if (get_user(options, uarg.i))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
pc87413_disable();
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
pc87413_enable();
retval = 0;
}
return retval;
}
}
}
/* -- Notifier funtions -----------------------------------------*/
/**
* notify_sys:
* @this: our notifier block
* @code: the event being reported
* @unused: unused
*
* Our notifier is called on system shutdowns. We want to turn the card
* off at reboot otherwise the machine will reboot again during memory
* test or worse yet during the following fsck. This would suck, in fact
* trust me - if it happens it does suck.
*/
static int pc87413_notify_sys(struct notifier_block *this,
unsigned long code,
void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
{
/* Turn the card off */
pc87413_disable();
}
return NOTIFY_DONE;
}
/* -- Module's structures ---------------------------------------*/
static const struct file_operations pc87413_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = pc87413_write,
.ioctl = pc87413_ioctl,
.open = pc87413_open,
.release = pc87413_release,
};
static struct notifier_block pc87413_notifier =
{
.notifier_call = pc87413_notify_sys,
};
static struct miscdevice pc87413_miscdev=
{
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &pc87413_fops
};
/* -- Module init functions -------------------------------------*/
/**
* pc87413_init: module's "constructor"
*
* Set up the WDT watchdog board. All we have to do is grab the
* resources we require and bitch if anyone beat us to them.
* The open() function will actually kick the board off.
*/
static int __init pc87413_init(void)
{
int ret;
printk(KERN_INFO PFX "Version " VERSION " at io 0x%X\n", WDT_INDEX_IO_PORT);
/* request_region(io, 2, "pc87413"); */
ret = register_reboot_notifier(&pc87413_notifier);
if (ret != 0) {
printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
ret);
}
ret = misc_register(&pc87413_miscdev);
if (ret != 0) {
printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
unregister_reboot_notifier(&pc87413_notifier);
return ret;
}
printk(KERN_INFO PFX "initialized. timeout=%d min \n", timeout);
pc87413_enable();
return 0;
}
/**
* pc87413_exit: module's "destructor"
*
* Unload the watchdog. You cannot do this with any file handles open.
* If your watchdog is set to continue ticking on close and you unload
* it, well it keeps ticking. We won't get the interrupt but the board
* will not touch PC memory so all is fine. You just have to load a new
* module in 60 seconds or reboot.
*/
static void __exit pc87413_exit(void)
{
/* Stop the timer before we leave */
if (!nowayout)
{
pc87413_disable();
printk(KERN_INFO MODNAME "Watchdog disabled.\n");
}
misc_deregister(&pc87413_miscdev);
unregister_reboot_notifier(&pc87413_notifier);
/* release_region(io,2); */
printk(MODNAME " watchdog component driver removed.\n");
}
module_init(pc87413_init);
module_exit(pc87413_exit);
MODULE_AUTHOR("Sven Anders <anders@anduras.de>, Marcus Junker <junker@anduras.de>,");
MODULE_DESCRIPTION("PC87413 WDT driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
module_param(io, int, 0);
MODULE_PARM_DESC(io, MODNAME " I/O port (default: " __MODULE_STRING(io) ").");
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in minutes (default=" __MODULE_STRING(timeout) ").");
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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