/*
- * 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
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h>
#include <linux/fs.h>
#include <linux/mm.h>
+#include <linux/slab.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <asm/watchdog.h>
-#define PFX "shwdt: "
+#define DRV_NAME "sh-wdt"
/*
* Default clock division ratio is 5.25 msecs. For an additional table of
* misses its deadline, the kernel timer will allow the WDT to overflow.
*/
static int clock_division_ratio = WTCSR_CKS_4096;
-
#define next_ping_period(cks) msecs_to_jiffies(cks - 4)
-static void sh_wdt_ping(unsigned long data);
-
-static unsigned long shwdt_is_open;
static const struct watchdog_info sh_wdt_info;
-static char shwdt_expect_close;
-static DEFINE_TIMER(timer, sh_wdt_ping, 0, 0);
-static unsigned long next_heartbeat;
+static struct platform_device *sh_wdt_dev;
static DEFINE_SPINLOCK(shwdt_lock);
#define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat */
static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
-
static int nowayout = WATCHDOG_NOWAYOUT;
+static unsigned long next_heartbeat;
-/**
- * sh_wdt_start - Start the Watchdog
- *
- * Starts the watchdog.
- */
-static void sh_wdt_start(void)
+struct sh_wdt {
+ void __iomem *base;
+ struct device *dev;
+
+ struct timer_list timer;
+
+ unsigned long enabled;
+ char expect_close;
+};
+
+static void sh_wdt_start(struct sh_wdt *wdt)
{
- __u8 csr;
unsigned long flags;
+ u8 csr;
spin_lock_irqsave(&shwdt_lock, flags);
next_heartbeat = jiffies + (heartbeat * HZ);
- mod_timer(&timer, next_ping_period(clock_division_ratio));
+ mod_timer(&wdt->timer, next_ping_period(clock_division_ratio));
csr = sh_wdt_read_csr();
csr |= WTCSR_WT | clock_division_ratio;
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)
+static void sh_wdt_stop(struct sh_wdt *wdt)
{
- __u8 csr;
unsigned long flags;
+ u8 csr;
spin_lock_irqsave(&shwdt_lock, flags);
- del_timer(&timer);
+ del_timer(&wdt->timer);
csr = sh_wdt_read_csr();
csr &= ~WTCSR_TME;
sh_wdt_write_csr(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)
+static inline void sh_wdt_keepalive(struct sh_wdt *wdt)
{
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)
{
+ struct sh_wdt *wdt = (struct sh_wdt *)data;
unsigned long flags;
spin_lock_irqsave(&shwdt_lock, flags);
if (time_before(jiffies, next_heartbeat)) {
- __u8 csr;
+ u8 csr;
csr = sh_wdt_read_csr();
csr &= ~WTCSR_IOVF;
sh_wdt_write_cnt(0);
- mod_timer(&timer, next_ping_period(clock_division_ratio));
+ mod_timer(&wdt->timer, next_ping_period(clock_division_ratio));
} else
- printk(KERN_WARNING PFX "Heartbeat lost! Will not ping "
- "the watchdog\n");
+ dev_warn(wdt->dev, "Heartbeat lost! Will not ping "
+ "the watchdog\n");
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))
+ struct sh_wdt *wdt = platform_get_drvdata(sh_wdt_dev);
+
+ if (test_and_set_bit(0, &wdt->enabled))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
- sh_wdt_start();
+ file->private_data = wdt;
+
+ sh_wdt_start(wdt);
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) {
- sh_wdt_stop();
+ struct sh_wdt *wdt = file->private_data;
+
+ if (wdt->expect_close == 42) {
+ sh_wdt_stop(wdt);
} else {
- printk(KERN_CRIT PFX "Unexpected close, not "
- "stopping watchdog!\n");
- sh_wdt_keepalive();
+ dev_crit(wdt->dev, "Unexpected close, not "
+ "stopping watchdog!\n");
+ sh_wdt_keepalive(wdt);
}
- clear_bit(0, &shwdt_is_open);
- shwdt_expect_close = 0;
+ clear_bit(0, &wdt->enabled);
+ wdt->expect_close = 0;
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)
{
+ struct sh_wdt *wdt = file->private_data;
+
if (count) {
if (!nowayout) {
size_t i;
- shwdt_expect_close = 0;
+ wdt->expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
- shwdt_expect_close = 42;
+ wdt->expect_close = 42;
}
}
- sh_wdt_keepalive();
+ sh_wdt_keepalive(wdt);
}
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)
{
+ struct sh_wdt *wdt = file->private_data;
int new_heartbeat;
int options, retval = -EINVAL;
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
- sh_wdt_stop();
+ sh_wdt_stop(wdt);
retval = 0;
}
if (options & WDIOS_ENABLECARD) {
- sh_wdt_start();
+ sh_wdt_start(wdt);
retval = 0;
}
return retval;
case WDIOC_KEEPALIVE:
- sh_wdt_keepalive();
+ sh_wdt_keepalive(wdt);
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_heartbeat, (int *)arg))
if (sh_wdt_set_heartbeat(new_heartbeat))
return -EINVAL;
- sh_wdt_keepalive();
+ sh_wdt_keepalive(wdt);
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(heartbeat, (int *)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)
{
+ struct sh_wdt *wdt = platform_get_drvdata(sh_wdt_dev);
+
if (code == SYS_DOWN || code == SYS_HALT)
- sh_wdt_stop();
+ sh_wdt_stop(wdt);
return NOTIFY_DONE;
}
.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)
+static int __devinit sh_wdt_probe(struct platform_device *pdev)
{
+ struct sh_wdt *wdt;
+ struct resource *res;
int rc;
- if (clock_division_ratio < 0x5 || clock_division_ratio > 0x7) {
- clock_division_ratio = WTCSR_CKS_4096;
- printk(KERN_INFO PFX
- "clock_division_ratio value must be 0x5<=x<=0x7, using %d\n",
- clock_division_ratio);
+ /*
+ * As this driver only covers the global watchdog case, reject
+ * any attempts to register per-CPU watchdogs.
+ */
+ if (pdev->id != -1)
+ return -EINVAL;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (unlikely(!res))
+ return -EINVAL;
+
+ if (!devm_request_mem_region(&pdev->dev, res->start,
+ resource_size(res), DRV_NAME))
+ return -EBUSY;
+
+ wdt = devm_kzalloc(&pdev->dev, sizeof(struct sh_wdt), GFP_KERNEL);
+ if (unlikely(!wdt)) {
+ rc = -ENOMEM;
+ goto out_release;
}
- rc = sh_wdt_set_heartbeat(heartbeat);
- if (unlikely(rc)) {
- heartbeat = WATCHDOG_HEARTBEAT;
- printk(KERN_INFO PFX
- "heartbeat value must be 1<=x<=3600, using %d\n",
- heartbeat);
+ wdt->dev = &pdev->dev;
+
+ wdt->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+ if (unlikely(!wdt->base)) {
+ rc = -ENXIO;
+ goto out_err;
}
rc = register_reboot_notifier(&sh_wdt_notifier);
if (unlikely(rc)) {
- printk(KERN_ERR PFX
+ dev_err(&pdev->dev,
"Can't register reboot notifier (err=%d)\n", rc);
- return rc;
+ goto out_unmap;
}
+ sh_wdt_miscdev.parent = wdt->dev;
+
rc = misc_register(&sh_wdt_miscdev);
if (unlikely(rc)) {
- printk(KERN_ERR PFX
+ dev_err(&pdev->dev,
"Can't register miscdev on minor=%d (err=%d)\n",
sh_wdt_miscdev.minor, rc);
- unregister_reboot_notifier(&sh_wdt_notifier);
- return rc;
+ goto out_unreg;
}
- printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
- heartbeat, nowayout);
+ init_timer(&wdt->timer);
+ wdt->timer.function = sh_wdt_ping;
+ wdt->timer.data = (unsigned long)wdt;
+ wdt->timer.expires = next_ping_period(clock_division_ratio);
+
+ platform_set_drvdata(pdev, wdt);
+ sh_wdt_dev = pdev;
+
+ dev_info(&pdev->dev, "initialized.\n");
return 0;
+
+out_unreg:
+ unregister_reboot_notifier(&sh_wdt_notifier);
+out_unmap:
+ devm_iounmap(&pdev->dev, wdt->base);
+out_err:
+ devm_kfree(&pdev->dev, wdt);
+out_release:
+ devm_release_mem_region(&pdev->dev, res->start, resource_size(res));
+
+ return rc;
}
-/**
- * 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)
+static int __devexit sh_wdt_remove(struct platform_device *pdev)
{
+ struct sh_wdt *wdt = platform_get_drvdata(pdev);
+ struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ platform_set_drvdata(pdev, NULL);
+
misc_deregister(&sh_wdt_miscdev);
+
+ sh_wdt_dev = NULL;
+
unregister_reboot_notifier(&sh_wdt_notifier);
+ devm_release_mem_region(&pdev->dev, res->start, resource_size(res));
+ devm_iounmap(&pdev->dev, wdt->base);
+ devm_kfree(&pdev->dev, wdt);
+
+ return 0;
}
+static struct platform_driver sh_wdt_driver = {
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+
+ .probe = sh_wdt_probe,
+ .remove = __devexit_p(sh_wdt_remove),
+};
+
+static int __init sh_wdt_init(void)
+{
+ int rc;
+
+ if (unlikely(clock_division_ratio < 0x5 ||
+ clock_division_ratio > 0x7)) {
+ clock_division_ratio = WTCSR_CKS_4096;
+
+ pr_info("%s: divisor must be 0x5<=x<=0x7, using %d\n",
+ DRV_NAME, clock_division_ratio);
+ }
+
+ rc = sh_wdt_set_heartbeat(heartbeat);
+ if (unlikely(rc)) {
+ heartbeat = WATCHDOG_HEARTBEAT;
+
+ pr_info("%s: heartbeat value must be 1<=x<=3600, using %d\n",
+ DRV_NAME, heartbeat);
+ }
+
+ pr_info("%s: configured with heartbeat=%d sec (nowayout=%d)\n",
+ DRV_NAME, heartbeat, nowayout);
+
+ return platform_driver_register(&sh_wdt_driver);
+}
+
+static void __exit sh_wdt_exit(void)
+{
+ platform_driver_unregister(&sh_wdt_driver);
+}
+module_init(sh_wdt_init);
+module_exit(sh_wdt_exit);
+
MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>");
MODULE_DESCRIPTION("SuperH watchdog driver");
MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
module_param(clock_division_ratio, int, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
-
-module_init(sh_wdt_init);
-module_exit(sh_wdt_exit);
git.openpandora.org / pandora-kernel.git / blobdiff