diff options
Diffstat (limited to 'drivers/watchdog/mpcore_wdt.c')
| -rw-r--r-- | drivers/watchdog/mpcore_wdt.c | 454 |
1 files changed, 0 insertions, 454 deletions
diff --git a/drivers/watchdog/mpcore_wdt.c b/drivers/watchdog/mpcore_wdt.c deleted file mode 100644 index 4f5ac408c7a3..000000000000 --- a/drivers/watchdog/mpcore_wdt.c +++ /dev/null @@ -1,454 +0,0 @@ -/* - * Watchdog driver for the mpcore watchdog timer - * - * (c) Copyright 2004 ARM Limited - * - * Based on the SoftDog driver: - * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>, - * All Rights Reserved. - * - * 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 Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - * - * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide - * warranty for any of this software. This material is provided - * "AS-IS" and at no charge. - * - * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk> - * - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#include <linux/module.h> -#include <linux/moduleparam.h> -#include <linux/types.h> -#include <linux/miscdevice.h> -#include <linux/watchdog.h> -#include <linux/fs.h> -#include <linux/reboot.h> -#include <linux/init.h> -#include <linux/interrupt.h> -#include <linux/platform_device.h> -#include <linux/uaccess.h> -#include <linux/slab.h> -#include <linux/io.h> - -#include <asm/smp_twd.h> - -struct mpcore_wdt { - unsigned long timer_alive; - struct device *dev; - void __iomem *base; - int irq; - unsigned int perturb; - char expect_close; -}; - -static struct platform_device *mpcore_wdt_pdev; -static DEFINE_SPINLOCK(wdt_lock); - -#define TIMER_MARGIN 60 -static int mpcore_margin = TIMER_MARGIN; -module_param(mpcore_margin, int, 0); -MODULE_PARM_DESC(mpcore_margin, - "MPcore timer margin in seconds. (0 < mpcore_margin < 65536, default=" - __MODULE_STRING(TIMER_MARGIN) ")"); - -static bool nowayout = WATCHDOG_NOWAYOUT; -module_param(nowayout, bool, 0); -MODULE_PARM_DESC(nowayout, - "Watchdog cannot be stopped once started (default=" - __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); - -#define ONLY_TESTING 0 -static int mpcore_noboot = ONLY_TESTING; -module_param(mpcore_noboot, int, 0); -MODULE_PARM_DESC(mpcore_noboot, "MPcore 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 mpcore_wdt_fire(int irq, void *arg) -{ - struct mpcore_wdt *wdt = arg; - - /* Check it really was our interrupt */ - if (readl(wdt->base + TWD_WDOG_INTSTAT)) { - dev_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; -} - -/* - * mpcore_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 mpcore_wdt_keepalive(struct mpcore_wdt *wdt) -{ - unsigned long count; - - spin_lock(&wdt_lock); - /* Assume prescale is set to 256 */ - count = __raw_readl(wdt->base + TWD_WDOG_COUNTER); - count = (0xFFFFFFFFU - count) * (HZ / 5); - count = (count / 256) * mpcore_margin; - - /* Reload the counter */ - writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD); - wdt->perturb = wdt->perturb ? 0 : 1; - spin_unlock(&wdt_lock); -} - -static void mpcore_wdt_stop(struct mpcore_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 mpcore_wdt_start(struct mpcore_wdt *wdt) -{ - dev_info(wdt->dev, "enabling watchdog\n"); - - /* This loads the count register but does NOT start the count yet */ - mpcore_wdt_keepalive(wdt); - - if (mpcore_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); - } -} - -static int mpcore_wdt_set_heartbeat(int t) -{ - if (t < 0x0001 || t > 0xFFFF) - return -EINVAL; - - mpcore_margin = t; - return 0; -} - -/* - * /dev/watchdog handling - */ -static int mpcore_wdt_open(struct inode *inode, struct file *file) -{ - struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_pdev); - - if (test_and_set_bit(0, &wdt->timer_alive)) - return -EBUSY; - - if (nowayout) - __module_get(THIS_MODULE); - - file->private_data = wdt; - - /* - * Activate timer - */ - mpcore_wdt_start(wdt); - - return nonseekable_open(inode, file); -} - -static int mpcore_wdt_release(struct inode *inode, struct file *file) -{ - struct mpcore_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) - mpcore_wdt_stop(wdt); - else { - dev_crit(wdt->dev, - "unexpected close, not stopping watchdog!\n"); - mpcore_wdt_keepalive(wdt); - } - clear_bit(0, &wdt->timer_alive); - wdt->expect_close = 0; - return 0; -} - -static ssize_t mpcore_wdt_write(struct file *file, const char *data, - size_t len, loff_t *ppos) -{ - struct mpcore_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; - } - } - mpcore_wdt_keepalive(wdt); - } - return len; -} - -static const struct watchdog_info ident = { - .options = WDIOF_SETTIMEOUT | - WDIOF_KEEPALIVEPING | - WDIOF_MAGICCLOSE, - .identity = "MPcore Watchdog", -}; - -static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) -{ - struct mpcore_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) { - mpcore_wdt_stop(wdt); - ret = 0; - } - if (uarg.i & WDIOS_ENABLECARD) { - mpcore_wdt_start(wdt); - ret = 0; - } - break; - - case WDIOC_KEEPALIVE: - mpcore_wdt_keepalive(wdt); - ret = 0; - break; - - case WDIOC_SETTIMEOUT: - ret = mpcore_wdt_set_heartbeat(uarg.i); - if (ret) - break; - - mpcore_wdt_keepalive(wdt); - /* Fall */ - case WDIOC_GETTIMEOUT: - uarg.i = mpcore_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 mpcore_wdt_shutdown(struct platform_device *pdev) -{ - struct mpcore_wdt *wdt = platform_get_drvdata(pdev); - - if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT) - mpcore_wdt_stop(wdt); -} - -/* - * Kernel Interfaces - */ -static const struct file_operations mpcore_wdt_fops = { - .owner = THIS_MODULE, - .llseek = no_llseek, - .write = mpcore_wdt_write, - .unlocked_ioctl = mpcore_wdt_ioctl, - .open = mpcore_wdt_open, - .release = mpcore_wdt_release, -}; - -static struct miscdevice mpcore_wdt_miscdev = { - .minor = WATCHDOG_MINOR, - .name = "watchdog", - .fops = &mpcore_wdt_fops, -}; - -static int mpcore_wdt_probe(struct platform_device *pdev) -{ - struct mpcore_wdt *wdt; - struct resource *res; - int ret; - - /* We only accept one device, and it must have an id of -1 */ - if (pdev->id != -1) - return -ENODEV; - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) - return -ENODEV; - - wdt = devm_kzalloc(&pdev->dev, sizeof(struct mpcore_wdt), GFP_KERNEL); - if (!wdt) - return -ENOMEM; - - wdt->dev = &pdev->dev; - wdt->irq = platform_get_irq(pdev, 0); - if (wdt->irq >= 0) { - ret = devm_request_irq(wdt->dev, wdt->irq, mpcore_wdt_fire, 0, - "mpcore_wdt", wdt); - if (ret) { - dev_err(wdt->dev, - "cannot register IRQ%d for watchdog\n", - wdt->irq); - return ret; - } - } - - wdt->base = devm_ioremap(wdt->dev, res->start, resource_size(res)); - if (!wdt->base) - return -ENOMEM; - - mpcore_wdt_miscdev.parent = &pdev->dev; - ret = misc_register(&mpcore_wdt_miscdev); - if (ret) { - dev_err(wdt->dev, - "cannot register miscdev on minor=%d (err=%d)\n", - WATCHDOG_MINOR, ret); - return ret; - } - - mpcore_wdt_stop(wdt); - platform_set_drvdata(pdev, wdt); - mpcore_wdt_pdev = pdev; - - return 0; -} - -static int mpcore_wdt_remove(struct platform_device *pdev) -{ - misc_deregister(&mpcore_wdt_miscdev); - - mpcore_wdt_pdev = NULL; - - return 0; -} - -#ifdef CONFIG_PM -static int mpcore_wdt_suspend(struct platform_device *pdev, pm_message_t msg) -{ - struct mpcore_wdt *wdt = platform_get_drvdata(pdev); - mpcore_wdt_stop(wdt); /* Turn the WDT off */ - return 0; -} - -static int mpcore_wdt_resume(struct platform_device *pdev) -{ - struct mpcore_wdt *wdt = platform_get_drvdata(pdev); - /* re-activate timer */ - if (test_bit(0, &wdt->timer_alive)) - mpcore_wdt_start(wdt); - return 0; -} -#else -#define mpcore_wdt_suspend NULL -#define mpcore_wdt_resume NULL -#endif - -/* work with hotplug and coldplug */ -MODULE_ALIAS("platform:mpcore_wdt"); - -static struct platform_driver mpcore_wdt_driver = { - .probe = mpcore_wdt_probe, - .remove = mpcore_wdt_remove, - .suspend = mpcore_wdt_suspend, - .resume = mpcore_wdt_resume, - .shutdown = mpcore_wdt_shutdown, - .driver = { - .owner = THIS_MODULE, - .name = "mpcore_wdt", - }, -}; - -static int __init mpcore_wdt_init(void) -{ - /* - * Check that the margin value is within it's range; - * if not reset to the default - */ - if (mpcore_wdt_set_heartbeat(mpcore_margin)) { - mpcore_wdt_set_heartbeat(TIMER_MARGIN); - pr_info("mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n", - TIMER_MARGIN); - } - - pr_info("MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n", - mpcore_noboot, mpcore_margin, nowayout); - - return platform_driver_register(&mpcore_wdt_driver); -} - -static void __exit mpcore_wdt_exit(void) -{ - platform_driver_unregister(&mpcore_wdt_driver); -} - -module_init(mpcore_wdt_init); -module_exit(mpcore_wdt_exit); - -MODULE_AUTHOR("ARM Limited"); -MODULE_DESCRIPTION("MPcore Watchdog Device Driver"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |