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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* RDC321x watchdog driver
*
* Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org>
*
* This driver is highly inspired from the cpu5_wdt driver
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/ioport.h>
#include <linux/timer.h>
#include <linux/completion.h>
#include <linux/jiffies.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/mfd/rdc321x.h>
#define RDC_WDT_MASK 0x80000000 /* Mask */
#define RDC_WDT_EN 0x00800000 /* Enable bit */
#define RDC_WDT_WTI 0x00200000 /* Generate CPU reset/NMI/WDT on timeout */
#define RDC_WDT_RST 0x00100000 /* Reset bit */
#define RDC_WDT_WIF 0x00040000 /* WDT IRQ Flag */
#define RDC_WDT_IRT 0x00000100 /* IRQ Routing table */
#define RDC_WDT_CNT 0x00000001 /* WDT count */
#define RDC_CLS_TMR 0x80003844 /* Clear timer */
#define RDC_WDT_INTERVAL (HZ/10+1)
static int ticks = 1000;
/* some device data */
static struct {
struct completion stop;
int running;
struct timer_list timer;
int queue;
int default_ticks;
unsigned long inuse;
spinlock_t lock;
struct pci_dev *sb_pdev;
int base_reg;
} rdc321x_wdt_device;
/* generic helper functions */
static void rdc321x_wdt_trigger(struct timer_list *unused)
{
unsigned long flags;
u32 val;
if (rdc321x_wdt_device.running)
ticks--;
/* keep watchdog alive */
spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
pci_read_config_dword(rdc321x_wdt_device.sb_pdev,
rdc321x_wdt_device.base_reg, &val);
val |= RDC_WDT_EN;
pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
rdc321x_wdt_device.base_reg, val);
spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
/* requeue?? */
if (rdc321x_wdt_device.queue && ticks)
mod_timer(&rdc321x_wdt_device.timer,
jiffies + RDC_WDT_INTERVAL);
else {
/* ticks doesn't matter anyway */
complete(&rdc321x_wdt_device.stop);
}
}
static void rdc321x_wdt_reset(void)
{
ticks = rdc321x_wdt_device.default_ticks;
}
static void rdc321x_wdt_start(void)
{
unsigned long flags;
if (!rdc321x_wdt_device.queue) {
rdc321x_wdt_device.queue = 1;
/* Clear the timer */
spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
rdc321x_wdt_device.base_reg, RDC_CLS_TMR);
/* Enable watchdog and set the timeout to 81.92 us */
pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
rdc321x_wdt_device.base_reg,
RDC_WDT_EN | RDC_WDT_CNT);
spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
mod_timer(&rdc321x_wdt_device.timer,
jiffies + RDC_WDT_INTERVAL);
}
/* if process dies, counter is not decremented */
rdc321x_wdt_device.running++;
}
static int rdc321x_wdt_stop(void)
{
if (rdc321x_wdt_device.running)
rdc321x_wdt_device.running = 0;
ticks = rdc321x_wdt_device.default_ticks;
return -EIO;
}
/* filesystem operations */
static int rdc321x_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &rdc321x_wdt_device.inuse))
return -EBUSY;
return stream_open(inode, file);
}
static int rdc321x_wdt_release(struct inode *inode, struct file *file)
{
clear_bit(0, &rdc321x_wdt_device.inuse);
return 0;
}
static long rdc321x_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
u32 value;
static const struct watchdog_info ident = {
.options = WDIOF_CARDRESET,
.identity = "RDC321x WDT",
};
unsigned long flags;
switch (cmd) {
case WDIOC_KEEPALIVE:
rdc321x_wdt_reset();
break;
case WDIOC_GETSTATUS:
/* Read the value from the DATA register */
spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
pci_read_config_dword(rdc321x_wdt_device.sb_pdev,
rdc321x_wdt_device.base_reg, &value);
spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
if (copy_to_user(argp, &value, sizeof(u32)))
return -EFAULT;
break;
case WDIOC_GETSUPPORT:
if (copy_to_user(argp, &ident, sizeof(ident)))
return -EFAULT;
break;
case WDIOC_SETOPTIONS:
if (copy_from_user(&value, argp, sizeof(int)))
return -EFAULT;
switch (value) {
case WDIOS_ENABLECARD:
rdc321x_wdt_start();
break;
case WDIOS_DISABLECARD:
return rdc321x_wdt_stop();
default:
return -EINVAL;
}
break;
default:
return -ENOTTY;
}
return 0;
}
static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (!count)
return -EIO;
rdc321x_wdt_reset();
return count;
}
static const struct file_operations rdc321x_wdt_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = rdc321x_wdt_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.open = rdc321x_wdt_open,
.write = rdc321x_wdt_write,
.release = rdc321x_wdt_release,
};
static struct miscdevice rdc321x_wdt_misc = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &rdc321x_wdt_fops,
};
static int rdc321x_wdt_probe(struct platform_device *pdev)
{
int err;
struct resource *r;
struct rdc321x_wdt_pdata *pdata;
pdata = dev_get_platdata(&pdev->dev);
if (!pdata) {
dev_err(&pdev->dev, "no platform data supplied\n");
return -ENODEV;
}
r = platform_get_resource_byname(pdev, IORESOURCE_IO, "wdt-reg");
if (!r) {
dev_err(&pdev->dev, "failed to get wdt-reg resource\n");
return -ENODEV;
}
rdc321x_wdt_device.sb_pdev = pdata->sb_pdev;
rdc321x_wdt_device.base_reg = r->start;
rdc321x_wdt_device.queue = 0;
rdc321x_wdt_device.default_ticks = ticks;
err = misc_register(&rdc321x_wdt_misc);
if (err < 0) {
dev_err(&pdev->dev, "misc_register failed\n");
return err;
}
spin_lock_init(&rdc321x_wdt_device.lock);
/* Reset the watchdog */
pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
rdc321x_wdt_device.base_reg, RDC_WDT_RST);
init_completion(&rdc321x_wdt_device.stop);
clear_bit(0, &rdc321x_wdt_device.inuse);
timer_setup(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
dev_info(&pdev->dev, "watchdog init success\n");
return 0;
}
static void rdc321x_wdt_remove(struct platform_device *pdev)
{
if (rdc321x_wdt_device.queue) {
rdc321x_wdt_device.queue = 0;
wait_for_completion(&rdc321x_wdt_device.stop);
}
misc_deregister(&rdc321x_wdt_misc);
}
static struct platform_driver rdc321x_wdt_driver = {
.probe = rdc321x_wdt_probe,
.remove = rdc321x_wdt_remove,
.driver = {
.name = "rdc321x-wdt",
},
};
module_platform_driver(rdc321x_wdt_driver);
MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
MODULE_DESCRIPTION("RDC321x watchdog driver");
MODULE_LICENSE("GPL");
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