diff options
Diffstat (limited to 'target/linux/ubicom32/files/drivers/watchdog/ubi32_wdt.c')
| -rw-r--r-- | target/linux/ubicom32/files/drivers/watchdog/ubi32_wdt.c | 630 |
1 files changed, 630 insertions, 0 deletions
diff --git a/target/linux/ubicom32/files/drivers/watchdog/ubi32_wdt.c b/target/linux/ubicom32/files/drivers/watchdog/ubi32_wdt.c new file mode 100644 index 000000000..2c5b92187 --- /dev/null +++ b/target/linux/ubicom32/files/drivers/watchdog/ubi32_wdt.c @@ -0,0 +1,630 @@ +/* + * 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) ")"); |