--- /dev/null +++ b/drivers/watchdog/cns3xxx_wdt.c @@ -0,0 +1,465 @@ +/******************************************************************************* + * + * drivers/watchdog/cns3xxx_wdt.c + * + * Watchdog timer driver for the CNS3XXX SOCs + * + * Author: Scott Shu + * + * Copyright (c) 2008 Cavium Networks + * + * This file is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, Version 2, as + * published by the Free Software Foundation. + * + * This file is distributed in the hope that it will be useful, + * but AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or + * NONINFRINGEMENT. See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this file; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA or + * visit http://www.gnu.org/licenses/. + * + * This file may also be available under a different license from Cavium. + * Contact Cavium Networks for more information + * + ******************************************************************************/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +struct cns3xxx_wdt { + unsigned long timer_alive; + struct device *dev; + void __iomem *base; + int irq; + unsigned int perturb; + char expect_close; +}; + +static struct platform_device *cns3xxx_wdt_dev; +extern unsigned int twd_timer_rate; +static spinlock_t wdt_lock; + +#define TIMER_MARGIN 60 +static int cns3xxx_margin = TIMER_MARGIN; +module_param(cns3xxx_margin, int, 0); +MODULE_PARM_DESC(cns3xxx_margin, + "CNS3XXX timer margin in seconds. (0 < cns3xxx_margin < 65536, default=" + __MODULE_STRING(TIMER_MARGIN) ")"); + +static int nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, + "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +#define ONLY_TESTING 0 +static int cns3xxx_noboot = ONLY_TESTING; +module_param(cns3xxx_noboot, int, 0); +MODULE_PARM_DESC(cns3xxx_noboot, "CNS3XXX watchdog action, " + "set to 1 to ignore reboots, 0 to reboot (default=" + __MODULE_STRING(ONLY_TESTING) ")"); + +/* + * This is the interrupt handler. Note that we only use this + * in testing mode, so don't actually do a reboot here. + */ +static irqreturn_t cns3xxx_wdt_fire(int irq, void *arg) +{ + struct cns3xxx_wdt *wdt = arg; + + /* Check it really was our interrupt */ + if (readl(wdt->base + TWD_WDOG_INTSTAT)) { + dev_printk(KERN_CRIT, wdt->dev, + "Triggered - Reboot ignored.\n"); + /* Clear the interrupt on the watchdog */ + writel(1, wdt->base + TWD_WDOG_INTSTAT); + return IRQ_HANDLED; + } + return IRQ_NONE; +} + +/* + * cns3xxx_wdt_keepalive - reload the timer + * + * Note that the spec says a DIFFERENT value must be written to the reload + * register each time. The "perturb" variable deals with this by adding 1 + * to the count every other time the function is called. + */ +static void cns3xxx_wdt_keepalive(struct cns3xxx_wdt *wdt) +{ + unsigned int count; + + /* Assume prescale is set to 256 */ + count = (twd_timer_rate / 256) * cns3xxx_margin; + + /* Reload the counter */ + spin_lock(&wdt_lock); + writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD); + wdt->perturb = wdt->perturb ? 0 : 1; + spin_unlock(&wdt_lock); +} + +static void cns3xxx_wdt_stop(struct cns3xxx_wdt *wdt) +{ + spin_lock(&wdt_lock); + writel(0x12345678, wdt->base + TWD_WDOG_DISABLE); + writel(0x87654321, wdt->base + TWD_WDOG_DISABLE); + writel(0x0, wdt->base + TWD_WDOG_CONTROL); + spin_unlock(&wdt_lock); +} + +static void cns3xxx_wdt_start(struct cns3xxx_wdt *wdt) +{ + dev_printk(KERN_INFO, wdt->dev, "enabling watchdog.\n"); + + //spin_lock(&wdt_lock); + /* This loads the count register but does NOT start the count yet */ + cns3xxx_wdt_keepalive(wdt); + spin_lock(&wdt_lock); + + if (cns3xxx_noboot) { + /* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */ + writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL); + } else { + /* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */ + writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL); + } + spin_unlock(&wdt_lock); +} + +static int cns3xxx_wdt_set_heartbeat(int t) +{ + if (t < 0x0001 || t > 0xFFFF) + return -EINVAL; + + cns3xxx_margin = t; + return 0; +} + +/* + * /dev/watchdog handling + */ +static int cns3xxx_wdt_open(struct inode *inode, struct file *file) +{ + struct cns3xxx_wdt *wdt = platform_get_drvdata(cns3xxx_wdt_dev); + + if (test_and_set_bit(0, &wdt->timer_alive)) + return -EBUSY; + + if (nowayout) + __module_get(THIS_MODULE); + + file->private_data = wdt; + + /* + * Activate timer + */ + cns3xxx_wdt_start(wdt); + + return nonseekable_open(inode, file); +} + +static int cns3xxx_wdt_release(struct inode *inode, struct file *file) +{ + struct cns3xxx_wdt *wdt = file->private_data; + + /* + * Shut off the timer. + * Lock it in if it's a module and we set nowayout + */ + if (wdt->expect_close == 42) + cns3xxx_wdt_stop(wdt); + else { + dev_printk(KERN_CRIT, wdt->dev, + "unexpected close, not stopping watchdog!\n"); + cns3xxx_wdt_keepalive(wdt); + } + clear_bit(0, &wdt->timer_alive); + wdt->expect_close = 0; + return 0; +} + +static ssize_t cns3xxx_wdt_write(struct file *file, const char *data, + size_t len, loff_t *ppos) +{ + struct cns3xxx_wdt *wdt = file->private_data; + + /* + * Refresh the timer. + */ + if (len) { + if (!nowayout) { + size_t i; + + /* In case it was set long ago */ + wdt->expect_close = 0; + + for (i = 0; i != len; i++) { + char c; + + if (get_user(c, data + i)) + return -EFAULT; + if (c == 'V') + wdt->expect_close = 42; + } + } + cns3xxx_wdt_keepalive(wdt); + } + return len; +} + +static struct watchdog_info ident = { + .options = WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, + .identity = "CNS3XXX Watchdog", +}; + +static long cns3xxx_wdt_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct cns3xxx_wdt *wdt = file->private_data; + int ret; + union { + struct watchdog_info ident; + int i; + } uarg; + + if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg)) + return -ENOTTY; + + if (_IOC_DIR(cmd) & _IOC_WRITE) { + ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd)); + if (ret) + return -EFAULT; + } + + switch (cmd) { + case WDIOC_GETSUPPORT: + uarg.ident = ident; + ret = 0; + break; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + uarg.i = 0; + ret = 0; + break; + + case WDIOC_SETOPTIONS: + ret = -EINVAL; + if (uarg.i & WDIOS_DISABLECARD) { + cns3xxx_wdt_stop(wdt); + ret = 0; + } + if (uarg.i & WDIOS_ENABLECARD) { + cns3xxx_wdt_start(wdt); + ret = 0; + } + break; + + case WDIOC_KEEPALIVE: + cns3xxx_wdt_keepalive(wdt); + ret = 0; + break; + + case WDIOC_SETTIMEOUT: + ret = cns3xxx_wdt_set_heartbeat(uarg.i); + if (ret) + break; + + cns3xxx_wdt_keepalive(wdt); + /* Fall */ + case WDIOC_GETTIMEOUT: + uarg.i = cns3xxx_margin; + ret = 0; + break; + + default: + return -ENOTTY; + } + + if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) { + ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd)); + if (ret) + ret = -EFAULT; + } + return ret; +} + +/* + * System shutdown handler. Turn off the watchdog if we're + * restarting or halting the system. + */ +static void cns3xxx_wdt_shutdown(struct platform_device *dev) +{ + struct cns3xxx_wdt *wdt = platform_get_drvdata(dev); + + if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT) + cns3xxx_wdt_stop(wdt); +} + +/* + * Kernel Interfaces + */ +static const struct file_operations cns3xxx_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = cns3xxx_wdt_write, + .unlocked_ioctl = cns3xxx_wdt_ioctl, + .open = cns3xxx_wdt_open, + .release = cns3xxx_wdt_release, +}; + +static struct miscdevice cns3xxx_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &cns3xxx_wdt_fops, +}; + +static int __devinit cns3xxx_wdt_probe(struct platform_device *dev) +{ + struct cns3xxx_wdt *wdt; + struct resource *res; + int ret; + + /* We only accept one device, and it must have an id of -1 */ + if (dev->id != -1) + return -ENODEV; + + res = platform_get_resource(dev, IORESOURCE_MEM, 0); + if (!res) { + ret = -ENODEV; + goto err_out; + } + + wdt = kzalloc(sizeof(struct cns3xxx_wdt), GFP_KERNEL); + if (!wdt) { + ret = -ENOMEM; + goto err_out; + } + + wdt->dev = &dev->dev; + wdt->irq = platform_get_irq(dev, 0); + if (wdt->irq < 0) { + ret = -ENXIO; + goto err_free; + } + wdt->base = ioremap(res->start, res->end - res->start + 1); + if (!wdt->base) { + ret = -ENOMEM; + goto err_free; + } + + cns3xxx_wdt_miscdev.parent = &dev->dev; + ret = misc_register(&cns3xxx_wdt_miscdev); + if (ret) { + dev_printk(KERN_ERR, wdt->dev, + "cannot register miscdev on minor=%d (err=%d)\n", + WATCHDOG_MINOR, ret); + goto err_misc; + } + + ret = request_irq(wdt->irq, cns3xxx_wdt_fire, IRQF_DISABLED, + dev->name, wdt); + if (ret) { + dev_printk(KERN_ERR, wdt->dev, + "cannot register IRQ%d for watchdog\n", wdt->irq); + goto err_irq; + } + + cns3xxx_wdt_stop(wdt); + platform_set_drvdata(dev, wdt); + cns3xxx_wdt_dev = dev; + + return 0; + +err_irq: + misc_deregister(&cns3xxx_wdt_miscdev); +err_misc: + platform_set_drvdata(dev, NULL); + iounmap(wdt->base); +err_free: + kfree(wdt); +err_out: + return ret; +} + +static int __devexit cns3xxx_wdt_remove(struct platform_device *dev) +{ + struct cns3xxx_wdt *wdt = platform_get_drvdata(dev); + + platform_set_drvdata(dev, NULL); + + misc_deregister(&cns3xxx_wdt_miscdev); + + cns3xxx_wdt_dev = NULL; + + free_irq(wdt->irq, wdt); + iounmap(wdt->base); + kfree(wdt); + return 0; +} + + +static struct platform_driver cns3xxx_wdt_driver = { + .probe = cns3xxx_wdt_probe, + .remove = __devexit_p(cns3xxx_wdt_remove), + .shutdown = cns3xxx_wdt_shutdown, + .driver = { + .owner = THIS_MODULE, + .name = "cns3xxx-wdt", + }, +}; + +static char banner[] __initdata = KERN_INFO + "CNS3XXX Watchdog Timer, noboot=%d margin=%d sec (nowayout= %d)\n"; + +static int __init cns3xxx_wdt_init(void) +{ + /* + * Check that the margin value is within it's range; + * if not reset to the default + */ + if (cns3xxx_wdt_set_heartbeat(cns3xxx_margin)) { + cns3xxx_wdt_set_heartbeat(TIMER_MARGIN); + printk(KERN_INFO "cns3xxx_margin value must be 0 < cns3xxx_margin < 65536, using %d\n", + TIMER_MARGIN); + } + + printk(banner, cns3xxx_noboot, cns3xxx_margin, nowayout); + + spin_lock_init(&wdt_lock); + + return platform_driver_register(&cns3xxx_wdt_driver); +} + +static void __exit cns3xxx_wdt_exit(void) +{ + platform_driver_unregister(&cns3xxx_wdt_driver); +} + +module_init(cns3xxx_wdt_init); +module_exit(cns3xxx_wdt_exit); + +MODULE_AUTHOR("Scott Shu"); +MODULE_DESCRIPTION("CNS3XXX Watchdog Device Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); +MODULE_ALIAS("platform:cns3xxx-wdt"); --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -231,6 +231,15 @@ config DAVINCI_WATCHDOG NOTE: once enabled, this timer cannot be disabled. Say N if you are unsure. +config CNS3XXX_WATCHDOG + tristate "CNS3XXX watchdog" + depends on ARCH_CNS3XXX && LOCAL_TIMERS + help + Watchdog timer embedded into the CNS3XXX SoCs system. + + To compile this driver as a module, choose M here: the + module will be called cns3xxx_wdt. + config ORION_WATCHDOG tristate "Orion watchdog" depends on ARCH_ORION5X || ARCH_KIRKWOOD --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -41,6 +41,7 @@ obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_ obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o obj-$(CONFIG_IOP_WATCHDOG) += iop_wdt.o obj-$(CONFIG_DAVINCI_WATCHDOG) += davinci_wdt.o +obj-$(CONFIG_CNS3XXX_WATCHDOG) += cns3xxx_wdt.o obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o