--- /dev/null
+/*
+ * drivers/watchdog/ubi32_wdt.c
+ * Ubicom32 Watchdog Driver
+ *
+ * Originally based on softdog.c
+ * Copyright 2006-2007 Analog Devices Inc.
+ * Copyright 2006-2007 Michele d'Amico
+ * Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>
+ * (C) Copyright 2009, Ubicom, Inc.
+ *
+ * This file is part of the Ubicom32 Linux Kernel Port.
+ *
+ * The Ubicom32 Linux Kernel Port 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.
+ *
+ * The Ubicom32 Linux Kernel Port is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with the Ubicom32 Linux Kernel Port. If not,
+ * see <http://www.gnu.org/licenses/>.
+ *
+ * Ubicom32 implementation derived from (with many thanks):
+ * arch/m68knommu
+ * arch/blackfin
+ * arch/parisc
+ */
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/fs.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/uaccess.h>
+#include <asm/ip5000.h>
+
+#define WATCHDOG_NAME "ubi32-wdt"
+#define PFX WATCHDOG_NAME ": "
+
+#define OSC1_FREQ 12000000
+#define WATCHDOG_SEC_TO_CYC(x) (OSC1_FREQ * (x))
+#define WATCHDOG_MAX_SEC (0xffffffff / OSC1_FREQ)
+
+#define MIN_PROCESSOR_ADDRESS 0x03000000
+
+static DEFINE_SPINLOCK(ubi32_wdt_spinlock);
+
+#define WATCHDOG_TIMEOUT 20
+
+#if defined(CONFIG_WATCHDOG_NOWAYOUT)
+#define WATCHDOG_NOWAYOUT 1
+#else
+#define WATCHDOG_NOWAYOUT 0
+#endif
+
+static unsigned int timeout = WATCHDOG_TIMEOUT;
+static int nowayout = WATCHDOG_NOWAYOUT;
+static struct watchdog_info ubi32_wdt_info;
+static unsigned long open_check;
+static char expect_close;
+
+#if !defined(CONFIG_SMP)
+#define UBI32_WDT_LOCK(lock, flags) local_irq_save(flags)
+#define UBI32_WDT_UNLOCK(lock, flags) local_irq_restore(flags)
+#define UBI32_WDT_LOCK_CHECK()
+#else
+#define UBI32_WDT_LOCK(lock, flags) spin_lock_irqsave((lock), (flags));
+#define UBI32_WDT_UNLOCK(lock, flags) spin_unlock_irqrestore((lock), (flags));
+#define UBI32_WDT_LOCK_CHECK() BUG_ON(!spin_is_locked(&ubi32_wdt_spinlock));
+#endif
+
+/*
+ * ubi32_wdt_remaining()
+ * Return the approximate number of seconds remaining
+ */
+static int ubi32_wdt_remaining(void)
+{
+ int compare;
+ int curr;
+
+ UBI32_WDT_LOCK_CHECK();
+
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, TIMER_TKEYVAL);
+ compare = ubicom32_read_reg(&UBICOM32_IO_TIMER->wdcom);
+ curr = ubicom32_read_reg(&UBICOM32_IO_TIMER->mptval);
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, 0);
+ return (compare - curr) / OSC1_FREQ;
+
+}
+
+/*
+ * ubi32_wdt_keepalive()
+ * Keep the Userspace Watchdog Alive
+ *
+ * The Userspace watchdog got a KeepAlive: schedule the next timeout.
+ */
+static int ubi32_wdt_keepalive(void)
+{
+ UBI32_WDT_LOCK_CHECK();
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, TIMER_TKEYVAL);
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->wdcom,
+ ubicom32_read_reg(&UBICOM32_IO_TIMER->mptval)
+ + WATCHDOG_SEC_TO_CYC(timeout));
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, 0);
+ return 0;
+}
+
+/*
+ * ubi32_wdt_stop()
+ * Stop the on-chip Watchdog
+ */
+static int ubi32_wdt_stop(void)
+{
+ UBI32_WDT_LOCK_CHECK();
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, TIMER_TKEYVAL);
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->wdcfg, TIMER_WATCHDOG_DISABLE);
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, 0);
+ return 0;
+}
+
+/*
+ * ubi32_wdt_start()
+ * Start the on-chip Watchdog
+ */
+static int ubi32_wdt_start(void)
+{
+ UBI32_WDT_LOCK_CHECK();
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, TIMER_TKEYVAL);
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->wdcom,
+ ubicom32_read_reg(&UBICOM32_IO_TIMER->mptval)
+ + WATCHDOG_SEC_TO_CYC(timeout));
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->wdcfg, ~TIMER_WATCHDOG_DISABLE);
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, 0);
+ return 0;
+}
+
+/*
+ * ubi32_wdt_running()
+ * Return true if the watchdog is configured
+ */
+static int ubi32_wdt_running(void)
+{
+ int enabled;
+
+ UBI32_WDT_LOCK_CHECK();
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, TIMER_TKEYVAL);
+ enabled = ubicom32_read_reg(&UBICOM32_IO_TIMER->wdcfg) == ~TIMER_WATCHDOG_DISABLE;
+ ubicom32_write_reg(&UBICOM32_IO_TIMER->tkey, 0);
+ return enabled;
+}
+
+/*
+ * ubi32_wdt_set_timeout()
+ * Set the Userspace Watchdog timeout
+ *
+ * - @t: new timeout value (in seconds)
+ */
+static int ubi32_wdt_set_timeout(unsigned long t)
+{
+ UBI32_WDT_LOCK_CHECK();
+
+ if (t > WATCHDOG_MAX_SEC) {
+ printk(KERN_WARNING PFX "request to large: %ld [1-%d] sec)\n", t, WATCHDOG_MAX_SEC);
+ return -EINVAL;
+ }
+
+ /*
+ * If we are running, then reset the time value so
+ * that the new value has an immediate effect.
+ */
+ timeout = t;
+ if (ubi32_wdt_running()) {
+ ubi32_wdt_keepalive();
+ }
+ return 0;
+}
+
+/*
+ * ubi32_wdt_open()
+ * Open the Device
+ */
+static int ubi32_wdt_open(struct inode *inode, struct file *file)
+{
+ unsigned long flags;
+
+ if (test_and_set_bit(0, &open_check))
+ return -EBUSY;
+
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ ubi32_wdt_start();
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+
+ return nonseekable_open(inode, file);
+}
+
+/*
+ * ubi32_wdt_close()
+ * Close the Device
+ */
+static int ubi32_wdt_release(struct inode *inode, struct file *file)
+{
+ unsigned long flags;
+
+ /*
+ * If we don't expect a close, then the watchdog continues
+ * even though the device is closed. The caller will have
+ * a full timeout value to reopen the device and continue
+ * stroking it.
+ */
+ if (expect_close != 42) {
+ printk(KERN_CRIT PFX
+ "Unexpected close, not stopping watchdog!\n");
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ ubi32_wdt_keepalive();
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+ } else {
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ ubi32_wdt_stop();
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+ }
+
+ expect_close = 0;
+ clear_bit(0, &open_check);
+ return 0;
+}
+
+/*
+ * ubi32_wdt_write()
+ * Write to Device
+ *
+ * If the user writes nothing, nothing happens.
+ * If the user writes a V, then we expect a close and allow a release.
+ * If the user writes anything else, it is ignored.
+ */
+static ssize_t ubi32_wdt_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ size_t i;
+ unsigned long flags;
+
+ /*
+ * Every write resets the expect_close. The last write
+ * must be a V to allow shutdown on close.
+ */
+ expect_close = 0;
+
+ /*
+ * Empty writes still ping.
+ */
+ if (!len) {
+ goto ping;
+ }
+
+ /*
+ * If nowayout is set, it does not matter if the caller
+ * is trying to send the magic 'V' we will not allow a
+ * close to stop us.
+ */
+ if (nowayout) {
+ goto ping;
+ }
+
+ /*
+ * See if the program wrote a 'V' and if so disable
+ * the watchdog on release.
+ */
+ for (i = 0; i < len; i++) {
+ char c;
+ if (get_user(c, data + i)) {
+ return -EFAULT;
+ }
+
+ if (c == 'V') {
+ expect_close = 42;
+ }
+ }
+
+ping:
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ ubi32_wdt_keepalive();
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+ return len;
+}
+
+/*
+ * ubi32_wdt_ioctl()
+ * Query the watchdog device.
+ *
+ * Query basic information from the device or ping it, as outlined by the
+ * watchdog API.
+ */
+static long ubi32_wdt_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &ubi32_wdt_info, sizeof(ubi32_wdt_info))) {
+ return -EFAULT;
+ }
+ return 0;
+
+ case WDIOC_GETSTATUS: {
+ unsigned long flags;
+ int running;
+
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ running = ubi32_wdt_running();
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+ return running;
+ }
+
+ case WDIOC_GETBOOTSTATUS:
+ return ubicom32_get_reset_reason();
+
+ case WDIOC_SETOPTIONS: {
+ unsigned long flags;
+ int options, ret = -EINVAL;
+
+ /*
+ * The sample application does not pass a pointer
+ * but directly passes a value of 1 or 2; however
+ * all of the implementations (and thus probably
+ * the real applications) pass a pointer to a value.
+ *
+ * It should be noted that WDIOC_SETOPTIONS is defined as
+ * _IOR(WATCHDOG_IOCTL_BASE, 4, int), which means
+ * that it should be an int and NOT a pointer.
+ *
+ * TODO: Examine this code for future chips.
+ * TODO: Report the sample code defect.
+ */
+ if ((int)p < MIN_PROCESSOR_ADDRESS) {
+ options = (int)p;
+ } else {
+ if (get_user(options, p))
+ return -EFAULT;
+ }
+
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ if (options & WDIOS_DISABLECARD) {
+ ubi32_wdt_stop();
+ ret = 0;
+ }
+ if (options & WDIOS_ENABLECARD) {
+ ubi32_wdt_start();
+ ret = 0;
+ }
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+ return ret;
+ }
+
+ case WDIOC_KEEPALIVE: {
+ unsigned long flags;
+
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ ubi32_wdt_keepalive();
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+ return 0;
+ }
+
+ case WDIOC_SETTIMEOUT: {
+ int new_timeout;
+ unsigned long flags;
+ int ret = 0;
+
+ if (get_user(new_timeout, p))
+ return -EFAULT;
+
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ ret = ubi32_wdt_set_timeout(new_timeout);
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+ return ret;
+
+ }
+
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, p);
+
+ case WDIOC_GETTIMELEFT: {
+ unsigned long flags;
+ int remaining = 0;
+
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ remaining = ubi32_wdt_remaining();
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+ return put_user(remaining, p);
+ }
+
+ default:
+ return -ENOTTY;
+ }
+}
+
+/*
+ * ubi32_wdt_notify_sys()
+ * Notification callback function for system events.
+ *
+ * Turn off the watchdog during a SYS_DOWN or SYS_HALT.
+ */
+static int ubi32_wdt_notify_sys(struct notifier_block *this,
+ unsigned long code, void *unused)
+{
+ if (code == SYS_DOWN || code == SYS_HALT) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ ubi32_wdt_stop();
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+ }
+
+ return NOTIFY_DONE;
+}
+
+#ifdef CONFIG_PM
+static int state_before_suspend;
+
+/*
+ * ubi32_wdt_suspend()
+ * suspend the watchdog
+ *
+ * Remember if the watchdog was running and stop it.
+ */
+static int ubi32_wdt_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ unsigned long flags;
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ state_before_suspend = ubi32_wdt_running();
+ ubi32_wdt_stop();
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+
+ return 0;
+}
+
+/*
+ * ubi32_wdt_resume()
+ * Resume the watchdog
+ *
+ * If the watchdog was running, turn it back on.
+ */
+static int ubi32_wdt_resume(struct platform_device *pdev)
+{
+ if (state_before_suspend) {
+ unsigned long flags;
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ ubi32_wdt_set_timeout(timeout);
+ ubi32_wdt_start();
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+ }
+
+ return 0;
+}
+#else
+# define ubi32_wdt_suspend NULL
+# define ubi32_wdt_resume NULL
+#endif
+
+static const struct file_operations ubi32_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = ubi32_wdt_write,
+ .unlocked_ioctl = ubi32_wdt_ioctl,
+ .open = ubi32_wdt_open,
+ .release = ubi32_wdt_release,
+};
+
+static struct miscdevice ubi32_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &ubi32_wdt_fops,
+};
+
+static struct watchdog_info ubi32_wdt_info = {
+ .identity = "Ubicom32 Watchdog",
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+};
+
+static struct notifier_block ubi32_wdt_notifier = {
+ .notifier_call = ubi32_wdt_notify_sys,
+};
+
+/*
+ * ubi32_wdt_probe()
+ * Probe/register the watchdog module
+ *
+ * Registers the misc device and notifier handler. Actual device
+ * initialization is handled by ubi32_wdt_open().
+ */
+static int __devinit ubi32_wdt_probe(struct platform_device *pdev)
+{
+ int ret;
+
+ ret = register_reboot_notifier(&ubi32_wdt_notifier);
+ if (ret) {
+ printk(KERN_ERR PFX
+ "cannot register reboot notifier (err=%d)\n", ret);
+ return ret;
+ }
+
+ ret = misc_register(&ubi32_wdt_miscdev);
+ if (ret) {
+ printk(KERN_ERR PFX
+ "cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
+ unregister_reboot_notifier(&ubi32_wdt_notifier);
+ return ret;
+ }
+
+ printk(KERN_INFO PFX "initialized: timeout=%d sec (nowayout=%d)\n",
+ timeout, nowayout);
+
+ return 0;
+}
+
+/*
+ * ubi32_wdt_remove()
+ * Uninstall the module
+ *
+ * Unregisters the misc device and notifier handler. Actual device
+ * deinitialization is handled by ubi32_wdt_close().
+ */
+static int __devexit ubi32_wdt_remove(struct platform_device *pdev)
+{
+ misc_deregister(&ubi32_wdt_miscdev);
+ unregister_reboot_notifier(&ubi32_wdt_notifier);
+ return 0;
+}
+
+static struct platform_device *ubi32_wdt_device;
+
+static struct platform_driver ubi32_wdt_driver = {
+ .probe = ubi32_wdt_probe,
+ .remove = __devexit_p(ubi32_wdt_remove),
+ .suspend = ubi32_wdt_suspend,
+ .resume = ubi32_wdt_resume,
+ .driver = {
+ .name = WATCHDOG_NAME,
+ .owner = THIS_MODULE,
+ },
+};
+
+/*
+ * ubi32_wdt_init()
+ * Initialize the watchdog.
+ *
+ * Checks the module params and registers the platform device & driver.
+ * Real work is in the platform probe function.
+ */
+static int __init ubi32_wdt_init(void)
+{
+ unsigned long flags;
+ int ret;
+
+ /*
+ * Check that the timeout value is within range
+ */
+ spin_lock_irqsave(&ubi32_wdt_spinlock, flags);
+ ret = ubi32_wdt_set_timeout(timeout);
+ spin_unlock_irqrestore(&ubi32_wdt_spinlock, flags);
+ if (ret) {
+ return ret;
+ }
+
+ /*
+ * Since this is an on-chip device and needs no board-specific
+ * resources, we'll handle all the platform device stuff here.
+ */
+ ret = platform_driver_register(&ubi32_wdt_driver);
+ if (ret) {
+ printk(KERN_ERR PFX "unable to register driver\n");
+ return ret;
+ }
+
+ ubi32_wdt_device = platform_device_register_simple(WATCHDOG_NAME, -1, NULL, 0);
+ if (IS_ERR(ubi32_wdt_device)) {
+ printk(KERN_ERR PFX "unable to register device\n");
+ platform_driver_unregister(&ubi32_wdt_driver);
+ return PTR_ERR(ubi32_wdt_device);
+ }
+
+ return 0;
+}
+
+/*
+ * ubi32_wdt_exit()
+ * Deinitialize module
+ *
+ * Back out the platform device & driver steps. Real work is in the
+ * platform remove function.
+ */
+static void __exit ubi32_wdt_exit(void)
+{
+ platform_device_unregister(ubi32_wdt_device);
+ platform_driver_unregister(&ubi32_wdt_driver);
+}
+
+module_init(ubi32_wdt_init);
+module_exit(ubi32_wdt_exit);
+
+MODULE_AUTHOR("Sol Kavy<sol@ubicom.com>");
+MODULE_DESCRIPTION("Ubicom32 Watchdog Device Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+
+module_param(timeout, uint, 0);
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in seconds. (1<=timeout<=((2^32)/SCLK), default="
+ __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default="
+ __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
projects / openwrt / svn-archive / archive.git / blobdiff