/*
- * drivers/char/watchdog/shwdt.c
+ * drivers/watchdog/shwdt.c
*
* Watchdog driver for integrated watchdog in the SuperH processors.
*
- * Copyright (C) 2001, 2002, 2003 Paul Mundt <lethal@linux-sh.org>
+ * Copyright (C) 2001 - 2010 Paul Mundt <lethal@linux-sh.org>
*
* 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
#define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat */
static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
-
static int nowayout = WATCHDOG_NOWAYOUT;
-/**
- * sh_wdt_start - Start the Watchdog
- *
- * Starts the watchdog.
- */
static void sh_wdt_start(void)
{
__u8 csr;
sh_wdt_write_csr(csr);
#ifdef CONFIG_CPU_SH2
- /*
- * Whoever came up with the RSTCSR semantics must've been smoking
- * some of the good stuff, since in addition to the WTCSR/WTCNT write
- * brain-damage, it's managed to fuck things up one step further..
- *
- * If we need to clear the WOVF bit, the upper byte has to be 0xa5..
- * but if we want to touch RSTE or RSTS, the upper byte has to be
- * 0x5a..
- */
csr = sh_wdt_read_rstcsr();
csr &= ~RSTCSR_RSTS;
sh_wdt_write_rstcsr(csr);
spin_unlock_irqrestore(&shwdt_lock, flags);
}
-/**
- * sh_wdt_stop - Stop the Watchdog
- * Stops the watchdog.
- */
static void sh_wdt_stop(void)
{
__u8 csr;
spin_unlock_irqrestore(&shwdt_lock, flags);
}
-/**
- * sh_wdt_keepalive - Keep the Userspace Watchdog Alive
- * The Userspace watchdog got a KeepAlive: schedule the next heartbeat.
- */
static inline void sh_wdt_keepalive(void)
{
unsigned long flags;
spin_unlock_irqrestore(&shwdt_lock, flags);
}
-/**
- * sh_wdt_set_heartbeat - Set the Userspace Watchdog heartbeat
- * Set the Userspace Watchdog heartbeat
- */
static int sh_wdt_set_heartbeat(int t)
{
unsigned long flags;
return 0;
}
-/**
- * sh_wdt_ping - Ping the Watchdog
- * @data: Unused
- *
- * Clears overflow bit, resets timer counter.
- */
static void sh_wdt_ping(unsigned long data)
{
unsigned long flags;
spin_unlock_irqrestore(&shwdt_lock, flags);
}
-/**
- * sh_wdt_open - Open the Device
- * @inode: inode of device
- * @file: file handle of device
- *
- * Watchdog device is opened and started.
- */
static int sh_wdt_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &shwdt_is_open))
return nonseekable_open(inode, file);
}
-/**
- * sh_wdt_close - Close the Device
- * @inode: inode of device
- * @file: file handle of device
- *
- * Watchdog device is closed and stopped.
- */
static int sh_wdt_close(struct inode *inode, struct file *file)
{
if (shwdt_expect_close == 42) {
return 0;
}
-/**
- * sh_wdt_write - Write to Device
- * @file: file handle of device
- * @buf: buffer to write
- * @count: length of buffer
- * @ppos: offset
- *
- * Pings the watchdog on write.
- */
static ssize_t sh_wdt_write(struct file *file, const char *buf,
size_t count, loff_t *ppos)
{
return count;
}
-/**
- * sh_wdt_mmap - map WDT/CPG registers into userspace
- * @file: file structure for the device
- * @vma: VMA to map the registers into
- *
- * A simple mmap() implementation for the corner cases where the counter
- * needs to be mapped in userspace directly. Due to the relatively small
- * size of the area, neighbouring registers not necessarily tied to the
- * CPG will also be accessible through the register page, so this remains
- * configurable for users that really know what they're doing.
- *
- * Additionaly, the register page maps in the CPG register base relative
- * to the nearest page-aligned boundary, which requires that userspace do
- * the appropriate CPU subtype math for calculating the page offset for
- * the counter value.
- */
-static int sh_wdt_mmap(struct file *file, struct vm_area_struct *vma)
-{
- int ret = -ENOSYS;
-
-#ifdef CONFIG_SH_WDT_MMAP
- unsigned long addr;
-
- /* Only support the simple cases where we map in a register page. */
- if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff)
- return -EINVAL;
-
- /*
- * Pick WTCNT as the start, it's usually the first register after the
- * FRQCR, and neither one are generally page-aligned out of the box.
- */
- addr = WTCNT & ~(PAGE_SIZE - 1);
-
- vma->vm_flags |= VM_IO;
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-
- if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
- PAGE_SIZE, vma->vm_page_prot)) {
- printk(KERN_ERR PFX "%s: io_remap_pfn_range failed\n",
- __func__);
- return -EAGAIN;
- }
-
- ret = 0;
-#endif
-
- return ret;
-}
-
-/**
- * sh_wdt_ioctl - Query Device
- * @file: file handle of device
- * @cmd: watchdog command
- * @arg: argument
- *
- * Query basic information from the device or ping it, as outlined by the
- * watchdog API.
- */
static long sh_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
return 0;
}
-/**
- * sh_wdt_notify_sys - Notifier Handler
- * @this: notifier block
- * @code: notifier event
- * @unused: unused
- *
- * Handles specific events, such as turning off the watchdog during a
- * shutdown event.
- */
static int sh_wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
.unlocked_ioctl = sh_wdt_ioctl,
.open = sh_wdt_open,
.release = sh_wdt_close,
- .mmap = sh_wdt_mmap,
};
static const struct watchdog_info sh_wdt_info = {
.fops = &sh_wdt_fops,
};
-/**
- * sh_wdt_init - Initialize module
- * Registers the device and notifier handler. Actual device
- * initialization is handled by sh_wdt_open().
- */
static int __init sh_wdt_init(void)
{
int rc;
return 0;
}
-/**
- * sh_wdt_exit - Deinitialize module
- * Unregisters the device and notifier handler. Actual device
- * deinitialization is handled by sh_wdt_close().
- */
static void __exit sh_wdt_exit(void)
{
misc_deregister(&sh_wdt_miscdev);
projects / firefly-linux-kernel-4.4.55.git / commitdiff