/*
* 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 Marcus Junker, <junker@anduras.de>
* and Sven Anders, <anders@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 Marcus Junker, Sven Anders nor ANDURAS AG
* admit liability nor provide warranty for any of this software.
* This material is provided "AS-IS" and at no charge.
*
* Release 1.00.
*
*/
/* #define DEBUG 1 */
#include <linux/config.h>
#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 WATCHDOG_NAME "pc87413 WDT"
#define PFX WATCHDOG_NAME ": "
#define DPFX WATCHDOG_NAME " - DEBUG: "
#define WDT_INDEX_IO_PORT (io+0) /* */
#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 */
#define WD_TIMEOUT 1 /* minutes (1 ... 255) */
static int pc87413_is_open=0;
/*
* You must set these - there is no sane way to probe for this board.
* You can use pc87413=x to set these now.
*/
/**
* module_params
*
* Setup options. The board isn't really probe-able so we have to
* get the user to tell us the configuration.
*/
static int io=0x2E; /* Normally used addres on Portwell Boards */
module_param(io, int, 0);
MODULE_PARM_DESC(wdt_io, WATCHDOG_NAME " io port (default 0x2E)");
static int timeout = WD_TIMEOUT; /* in minutes */
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in minutes. 1<= timeout <=63, default=" __MODULE_STRING(WD_TIMEOUT) ".");
/******************************************
* Helper functions
******************************************/
static void
pc87413_select_wdt_out (void)
{
unsigned int cr_data=0;
/* 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
}
static 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
}
static 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;
}
static 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
}
static 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
}
static 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
}
static 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
}
static 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
}
static 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
}
static 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
}
static void
pc87413_disable(void)
{
unsigned int swc_base_addr;
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);
}
static void
pc87413_refresh(char pc87413_time)
{
unsigned int swc_base_addr;
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, pc87413_time);
pc87413_enable_wden(swc_base_addr);
pc87413_enable_sw_wd_tren(swc_base_addr);
pc87413_enable_sw_wd_trg(swc_base_addr);
}
static void
pc87413_enable(char pc87413_time)
{
unsigned int swc_base_addr;
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, pc87413_time);
pc87413_enable_wden(swc_base_addr);
pc87413_enable_sw_wd_tren(swc_base_addr);
pc87413_enable_sw_wd_trg(swc_base_addr);
}
/*******************************************
* Kernel methods.
*******************************************/
/**
* pc87413_status:
*
* Extract the status information from a WDT watchdog device. There are
* several board variants so we have to know which bits are valid. Some
* bits default to one and some to zero in order to be maximally painful.
*
* we then map the bits onto the status ioctl flags.
*/
static int pc87413_status(void)
{
/* Not supported */
return 1;
}
static long long pc87413_llseek(struct file *file, long long offset, int origin)
{
return -ESPIPE;
}
/**
* pc87413_write:
* @file: file handle to the watchdog
* @buf: buffer to write (unused as data does not matter here
* @count: count of 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 *buf, size_t count, loff_t *ppos)
{
if (count) {
pc87413_refresh (WD_TIMEOUT);
#ifdef DEBUG
printk(KERN_INFO DPFX "Write\n");
#endif
}
return count;
}
/*
* Read reports the temperature in degrees Fahrenheit.
*/
static ssize_t
pc87413_read(struct file *file, char *buf, size_t count, loff_t *ptr)
{
// char timeout;
//
// outb_p(0x08, WDT_EFER); /* Select locical device 8 */
// outb_p(0x0F6, WDT_EFER); /* Select CRF6 */
// timeout = inb(WDT_EFDR); /* Read Timeout counter from CRF6 */
// if(copy_to_user(buf,&timeout,1))
// return -EFAULT;
return 1;
}
/**
* 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)
{
static struct watchdog_info ident=
{
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "pc87413(HF/F)"
};
ident.options=1; /* Mask down to the card we have */
switch(cmd)
{
default:
return -ENOIOCTLCMD;
case WDIOC_GETSUPPORT:
return copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))?-EFAULT:0;
case WDIOC_GETSTATUS:
return put_user(pc87413_status(),(int *)arg);
case WDIOC_GETBOOTSTATUS:
return put_user(0, (int *)arg);
case WDIOC_KEEPALIVE:
pc87413_refresh(WD_TIMEOUT);
#ifdef DEBUG
printk(KERN_INFO DPFX "keepalive\n");
#endif
return 0;
}
}
/**
* pc87413_open:
* @inode: inode of device
* @file: file handle to device
*
* One of our two misc devices has been opened. The watchdog device is
* single open and on opening we load the counters. Counter zero is a
* 100Hz cascade, into counter 1 which downcounts to reboot. When the
* counter triggers counter 2 downcounts the length of the reset pulse
* which set set to be as long as possible.
*/
static int
pc87413_open(struct inode *inode, struct file *file)
{
switch(MINOR(inode->i_rdev))
{
case WATCHDOG_MINOR:
if(pc87413_is_open)
return -EBUSY;
/*
* Activate
*/
pc87413_is_open=1;
pc87413_refresh(WD_TIMEOUT);
#ifdef DEBUG
printk(KERN_INFO DPFX "Open\n");
#endif
return 0;
case TEMP_MINOR:
return 0;
default:
return -ENODEV;
}
}
/**
* pc87413_close:
* @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)
{
if(MINOR(inode->i_rdev)==WATCHDOG_MINOR)
{
#ifndef CONFIG_WATCHDOG_NOWAYOUT
pc87413_disable();
#endif
pc87413_is_open=0;
#ifdef DEBUG
printk(KERN_INFO DPFX "Release\n");
#endif
}
return 0;
}
/**
* 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;
}
/*****************************************************
* Kernel Interfaces
*****************************************************/
static struct file_operations pc87413_fops = {
.owner = THIS_MODULE,
.llseek = pc87413_llseek,
.read = pc87413_read,
.write = pc87413_write,
.ioctl = pc87413_ioctl,
.open = pc87413_open,
.release = pc87413_release,
};
static struct miscdevice pc87413_miscdev=
{
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &pc87413_fops
};
/*
* The WDT card needs to learn about soft shutdowns in order to
* turn the timebomb registers off.
*/
static struct notifier_block pc87413_notifier=
{
pc87413_notify_sys,
NULL,
0
};
/**
* pc87413_exit:
*
* 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
pc87413_exit(void)
{
pc87413_disable();
misc_deregister(&pc87413_miscdev);
unregister_reboot_notifier(&pc87413_notifier);
/* release_region(io,2); */
}
/**
* pc87413_init:
*
* 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
pc87413_init(void)
{
int ret;
printk(KERN_INFO PFX "Version 1.00 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(WD_TIMEOUT);
return 0;
}
module_init(pc87413_init);
module_exit(pc87413_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marcus Junker <junker@anduras.de>, Sven Anders <anders@anduras.de>");
MODULE_DESCRIPTION("PC87413 WDT driver");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
