/*
* 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 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",
pm_iobase);
goto exit;
}
/* Find the watchdog base address. */
outb(SP5100_PM_WATCHDOG_BASE3, SP5100_IO_PM_INDEX_REG);
val = inb(SP5100_IO_PM_DATA_REG);
outb(SP5100_PM_WATCHDOG_BASE2, SP5100_IO_PM_INDEX_REG);
val = val << 8 | inb(SP5100_IO_PM_DATA_REG);
outb(SP5100_PM_WATCHDOG_BASE1, SP5100_IO_PM_INDEX_REG);
val = val << 8 | inb(SP5100_IO_PM_DATA_REG);
outb(SP5100_PM_WATCHDOG_BASE0, SP5100_IO_PM_INDEX_REG);
/* Low three bits of BASE0 are reserved. */
val = val << 8 | (inb(SP5100_IO_PM_DATA_REG) & 0xf8);
tcobase = ioremap(val, SP5100_WDT_MEM_MAP_SIZE);
if (tcobase == 0) {
printk(KERN_ERR PFX "failed to get tcobase address\n");
goto unreg_region;
}
/* Enable watchdog decode bit */
pci_read_config_dword(sp5100_tco_pci,
SP5100_PCI_WATCHDOG_MISC_REG,
&val);
val |= SP5100_PCI_WATCHDOG_DECODE_EN;
pci_write_config_dword(sp5100_tco_pci,
SP5100_PCI_WATCHDOG_MISC_REG,
val);
/* Enable Watchdog timer and set the resolution to 1 sec. */
outb(SP5100_PM_WATCHDOG_CONTROL, SP5100_IO_PM_INDEX_REG);
val = inb(SP5100_IO_PM_DATA_REG);
val |= SP5100_PM_WATCHDOG_SECOND_RES;
val &= ~SP5100_PM_WATCHDOG_DISABLE;
outb(val, SP5100_IO_PM_DATA_REG);
/* Check that the watchdog action is set to reset the system. */
val = readl(SP5100_WDT_CONTROL(tcobase));
val &= ~SP5100_PM_WATCHDOG_ACTION_RESET;
writel(val, SP5100_WDT_CONTROL(tcobase));
/* Set a reasonable heartbeat before we stop the timer */
tco_timer_set_heartbeat(heartbeat);
/*
* Stop the TCO before we change anything so we don't race with
* a zeroed timer.
*/
tco_timer_stop();
/* Done */
return 1;
iounmap(tcobase);
unreg_region:
release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
exit:
return 0;
}
static int __devinit sp5100_tco_init(struct platform_device *dev)
{
int ret;
u32 val;
/* Check whether or not the hardware watchdog is there. If found, then
* set it up.
*/
if (!sp5100_tco_setupdevice())
return -ENODEV;
/* Check to see if last reboot was due to watchdog timeout */
printk(KERN_INFO PFX "Watchdog reboot %sdetected.\n",
readl(SP5100_WDT_CONTROL(tcobase)) & SP5100_PM_WATCHDOG_FIRED ?
"" : "not ");
/* Clear out the old status */
val = readl(SP5100_WDT_CONTROL(tcobase));
val &= ~SP5100_PM_WATCHDOG_FIRED;
writel(val, SP5100_WDT_CONTROL(tcobase));
/*
* Check that the heartbeat value is within it's range.
* If not, reset to the default.
*/
if (tco_timer_set_heartbeat(heartbeat)) {
heartbeat = WATCHDOG_HEARTBEAT;
tco_timer_set_heartbeat(heartbeat);
}
ret = misc_register(&sp5100_tco_miscdev);
if (ret != 0) {
printk(KERN_ERR PFX "cannot register miscdev on minor="
"%d (err=%d)\n",
WATCHDOG_MINOR, ret);
goto exit;
}
clear_bit(0, &timer_alive);
printk(KERN_INFO PFX "initialized (0x%p). heartbeat=%d sec"
" (nowayout=%d)\n",
tcobase, heartbeat, nowayout);
return 0;
exit:
iounmap(tcobase);
release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
return ret;
}
static void __devexit sp5100_tco_cleanup(void)
{
/* Stop the timer before we leave */
if (!nowayout)
tco_timer_stop();
/* Deregister */
misc_deregister(&sp5100_tco_miscdev);
iounmap(tcobase);
release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE);
}
static int __devexit sp5100_tco_remove(struct platform_device *dev)
{
if (tcobase)
sp5100_tco_cleanup();
return 0;
}
static void sp5100_tco_shutdown(struct platform_device *dev)
{
tco_timer_stop();
}
static struct platform_driver sp5100_tco_driver = {
.probe = sp5100_tco_init,
.remove = __devexit_p(sp5100_tco_remove),
.shutdown = sp5100_tco_shutdown,
.driver = {
.owner = THIS_MODULE,
.name = TCO_MODULE_NAME,
},
};
static int __init sp5100_tco_init_module(void)
{
int err;
printk(KERN_INFO PFX "SP5100 TCO WatchDog Timer Driver v%s\n",
TCO_VERSION);
err = platform_driver_register(&sp5100_tco_driver);
if (err)
return err;
sp5100_tco_platform_device = platform_device_register_simple(
TCO_MODULE_NAME, -1, NULL, 0);
if (IS_ERR(sp5100_tco_platform_device)) {
err = PTR_ERR(sp5100_tco_platform_device);
goto unreg_platform_driver;
}
return 0;
unreg_platform_driver:
platform_driver_unregister(&sp5100_tco_driver);
return err;
}
static void __exit sp5100_tco_cleanup_module(void)
{
platform_device_unregister(sp5100_tco_platform_device);
platform_driver_unregister(&sp5100_tco_driver);
printk(KERN_INFO PFX "SP5100 TCO Watchdog Module Unloaded.\n");
}
module_init(sp5100_tco_init_module);
module_exit(sp5100_tco_cleanup_module);
MODULE_AUTHOR("Priyanka Gupta");
MODULE_DESCRIPTION("TCO timer driver for SP5100 chipset");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
