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/*
* sp5100_tco : TCO timer driver for sp5100 chipsets
*
* (c) Copyright 2009 Google Inc., All Rights Reserved.
*
* Based on i8xx_tco.c:
* (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
* Reserved.
* http://www.kernelconcepts.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.
*
* See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide"
*/
/*
* Includes, defines, variables, module parameters, ...
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include "sp5100_tco.h"
/* Module and version information */
#define TCO_VERSION "0.01"
#define TCO_MODULE_NAME "SP5100 TCO timer"
#define TCO_DRIVER_NAME TCO_MODULE_NAME ", v" TCO_VERSION
#define PFX TCO_MODULE_NAME ": "
/* internal variables */
static u32 tcobase_phys;
static void __iomem *tcobase;
static unsigned int pm_iobase;
static DEFINE_SPINLOCK(tco_lock); /* Guards the hardware */
static unsigned long timer_alive;
static char tco_expect_close;
static struct pci_dev *sp5100_tco_pci;
/* the watchdog platform device */
static struct platform_device *sp5100_tco_platform_device;
/* module parameters */
#define WATCHDOG_HEARTBEAT 60 /* 60 sec default heartbeat. */
static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
__MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"
" (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
/*
* Some TCO specific functions
*/
static void tco_timer_start(void)
{
u32 val;
unsigned long flags;
spin_lock_irqsave(&tco_lock, flags);
val = readl(SP5100_WDT_CONTROL(tcobase));
val |= SP5100_WDT_START_STOP_BIT;
writel(val, SP5100_WDT_CONTROL(tcobase));
spin_unlock_irqrestore(&tco_lock, flags);
}
static void tco_timer_stop(void)
{
u32 val;
unsigned long flags;
spin_lock_irqsave(&tco_lock, flags);
val = readl(SP5100_WDT_CONTROL(tcobase));
val &= ~SP5100_WDT_START_STOP_BIT;
writel(val, SP5100_WDT_CONTROL(tcobase));
spin_unlock_irqrestore(&tco_lock, flags);
}
static void tco_timer_keepalive(void)
{
u32 val;
unsigned long flags;
spin_lock_irqsave(&tco_lock, flags);
val = readl(SP5100_WDT_CONTROL(tcobase));
val |= SP5100_WDT_TRIGGER_BIT;
writel(val, SP5100_WDT_CONTROL(tcobase));
spin_unlock_irqrestore(&tco_lock, flags);
}
static int tco_timer_set_heartbeat(int t)
{
unsigned long flags;
if (t < 0 || t > 0xffff)
return -EINVAL;
/* Write new heartbeat to watchdog */
spin_lock_irqsave(&tco_lock, flags);
writel(t, SP5100_WDT_COUNT(tcobase));
spin_unlock_irqrestore(&tco_lock, flags);
heartbeat = t;
return 0;
}
/*
* /dev/watchdog handling
*/
static int sp5100_tco_open(struct inode *inode, struct file *file)
{
/* /dev/watchdog can only be opened once */
if (test_and_set_bit(0, &timer_alive))
return -EBUSY;
/* Reload and activate timer */
tco_timer_start();
tco_timer_keepalive();
return nonseekable_open(inode, file);
}
static int sp5100_tco_release(struct inode *inode, struct file *file)
{
/* Shut off the timer. */
if (tco_expect_close == 42) {
tco_timer_stop();
} else {
printk(KERN_CRIT PFX
"Unexpected close, not stopping watchdog!\n");
tco_timer_keepalive();
}
clear_bit(0, &timer_alive);
tco_expect_close = 0;
return 0;
}
static ssize_t sp5100_tco_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;
/* note: just in case someone wrote the magic character
* five months ago... */
tco_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')
tco_expect_close = 42;
}
}
/* someone wrote to us, we should reload the timer */
tco_timer_keepalive();
}
return len;
}
static long sp5100_tco_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int new_options, retval = -EINVAL;
int new_heartbeat;
void __user *argp = (void __user *)arg;
int __user *p = argp;
static const struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
.firmware_version = 0,
.identity = TCO_MODULE_NAME,
};
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &ident,
sizeof(ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_SETOPTIONS:
if (get_user(new_options, p))
return -EFAULT;
if (new_options & WDIOS_DISABLECARD) {
tco_timer_stop();
retval = 0;
}
if (new_options & WDIOS_ENABLECARD) {
tco_timer_start();
tco_timer_keepalive();
retval = 0;
}
return retval;
case WDIOC_KEEPALIVE:
tco_timer_keepalive();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_heartbeat, p))
return -EFAULT;
if (tco_timer_set_heartbeat(new_heartbeat))
return -EINVAL;
tco_timer_keepalive();
/* Fall through */
case WDIOC_GETTIMEOUT:
return put_user(heartbeat, p);
default:
return -ENOTTY;
}
}
/*
* Kernel Interfaces
*/
static const struct file_operations sp5100_tco_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = sp5100_tco_write,
.unlocked_ioctl = sp5100_tco_ioctl,
.open = sp5100_tco_open,
.release = sp5100_tco_release,
};
static struct miscdevice sp5100_tco_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &sp5100_tco_fops,
};
/*
* Data for PCI driver interface
*
* This data only exists for exporting the supported
* PCI ids via MODULE_DEVICE_TABLE. We do not actually
* register a pci_driver, because someone else might
* want to register another driver on the same PCI id.
*/
static DEFINE_PCI_DEVICE_TABLE(sp5100_tco_pci_tbl) = {
{ PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID,
PCI_ANY_ID, },
{ 0, }, /* End of list */
};
MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);
/*
* Init & exit routines
*/
static unsigned char __devinit sp5100_tco_setupdevice(void)
{
struct pci_dev *dev = NULL;
u32 val;
/* Match the PCI device */
for_each_pci_dev(dev) {
if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) {
sp5100_tco_pci = dev;
break;
}
}
if (!sp5100_tco_pci)
return 0;
/* Request the IO ports used by this driver */
pm_iobase = SP5100_IO_PM_INDEX_REG;
if (!request_region(pm_iobase, SP5100_PM_IOPORTS_SIZE, "SP5100 TCO")) {
printk(KERN_ERR PFX "I/O address 0x%04x already in use\n"<
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