diff options
| -rw-r--r-- | drivers/char/watchdog/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/char/watchdog/Makefile | 1 | ||||
| -rw-r--r-- | drivers/char/watchdog/mpcore_wdt.c | 434 |
3 files changed, 444 insertions, 0 deletions
diff --git a/drivers/char/watchdog/Kconfig b/drivers/char/watchdog/Kconfig index c3898afce3a..fa789ea36bb 100644 --- a/drivers/char/watchdog/Kconfig +++ b/drivers/char/watchdog/Kconfig @@ -139,6 +139,15 @@ config SA1100_WATCHDOG To compile this driver as a module, choose M here: the module will be called sa1100_wdt. +config MPCORE_WATCHDOG + tristate "MPcore watchdog" + depends on WATCHDOG && ARM_MPCORE_PLATFORM && LOCAL_TIMERS + help + Watchdog timer embedded into the MPcore system. + + To compile this driver as a module, choose M here: the + module will be called mpcore_wdt. + # X86 (i386 + ia64 + x86_64) Architecture config ACQUIRE_WDT diff --git a/drivers/char/watchdog/Makefile b/drivers/char/watchdog/Makefile index cfeac6f1013..bc6f5fe88c8 100644 --- a/drivers/char/watchdog/Makefile +++ b/drivers/char/watchdog/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_IXP2000_WATCHDOG) += ixp2000_wdt.o obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o +obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o # X86 (i386 + ia64 + x86_64) Architecture obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o diff --git a/drivers/char/watchdog/mpcore_wdt.c b/drivers/char/watchdog/mpcore_wdt.c new file mode 100644 index 00000000000..c694eee1fb2 --- /dev/null +++ b/drivers/char/watchdog/mpcore_wdt.c @@ -0,0 +1,434 @@ +/* + * Watchdog driver for the mpcore watchdog timer + * + * (c) Copyright 2004 ARM Limited + * + * Based on the SoftDog driver: + * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved. + * http://www.redhat.com + * + * 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> + * + */ +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/config.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/device.h> +#include <asm/uaccess.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_dev; + +extern unsigned int mpcore_timer_rate; + +#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 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 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 pt_regs *regs) +{ + struct mpcore_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; +} + +/* + * 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 int count; + + /* Assume prescale is set to 256 */ + count = (mpcore_timer_rate / 256) * mpcore_margin; + + /* Reload the counter */ + writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD); + + wdt->perturb = wdt->perturb ? 0 : 1; +} + +static void mpcore_wdt_stop(struct mpcore_wdt *wdt) +{ + writel(0x12345678, wdt->base + TWD_WDOG_DISABLE); + writel(0x87654321, wdt->base + TWD_WDOG_DISABLE); + writel(0x0, wdt->base + TWD_WDOG_CONTROL); +} + +static void mpcore_wdt_start(struct mpcore_wdt *wdt) +{ + dev_printk(KERN_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 = dev_get_drvdata(&mpcore_wdt_dev->dev); + + 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_printk(KERN_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; + + /* Can't seek (pwrite) on this device */ + if (ppos != &file->f_pos) + return -ESPIPE; + + /* + * 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 struct watchdog_info ident = { + .options = WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, + .identity = "MPcore Watchdog", +}; + +static int mpcore_wdt_ioctl(struct inode *inode, 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 -ENOIOCTLCMD; + + 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_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_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + uarg.i = 0; + 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 -ENOIOCTLCMD; + } + + 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 device *_dev) +{ + struct mpcore_wdt *wdt = dev_get_drvdata(_dev); + + if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT) + mpcore_wdt_stop(wdt); +} + +/* + * Kernel Interfaces + */ +static struct file_operations mpcore_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = mpcore_wdt_write, + .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 __devinit mpcore_wdt_probe(struct device *_dev) +{ + struct platform_device *dev = to_platform_device(_dev); + struct mpcore_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 = kmalloc(sizeof(struct mpcore_wdt), GFP_KERNEL); + if (!wdt) { + ret = -ENOMEM; + goto err_out; + } + memset(wdt, 0, sizeof(struct mpcore_wdt)); + + wdt->dev = &dev->dev; + wdt->irq = platform_get_irq(dev, 0); + wdt->base = ioremap(res->start, res->end - res->start + 1); + if (!wdt->base) { + ret = -ENOMEM; + goto err_free; + } + + mpcore_wdt_miscdev.dev = &dev->dev; + ret = misc_register(&mpcore_wdt_miscdev); + if (ret) { + dev_printk(KERN_ERR, _dev, "cannot register miscdev on minor=%d (err=%d)\n", + WATCHDOG_MINOR, ret); + goto err_misc; + } + + ret = request_irq(wdt->irq, mpcore_wdt_fire, SA_INTERRUPT, "mpcore_wdt", wdt); + if (ret) { + dev_printk(KERN_ERR, _dev, "cannot register IRQ%d for watchdog\n", wdt->irq); + goto err_irq; + } + + mpcore_wdt_stop(wdt); + dev_set_drvdata(&dev->dev, wdt); + mpcore_wdt_dev = dev; + + return 0; + + err_irq: + misc_deregister(&mpcore_wdt_miscdev); + err_misc: + iounmap(wdt->base); + err_free: + kfree(wdt); + err_out: + return ret; +} + +static int __devexit mpcore_wdt_remove(struct device *dev) +{ + struct mpcore_wdt *wdt = dev_get_drvdata(dev); + + dev_set_drvdata(dev, NULL); + + misc_deregister(&mpcore_wdt_miscdev); + + mpcore_wdt_dev = NULL; + + free_irq(wdt->irq, wdt); + iounmap(wdt->base); + kfree(wdt); + return 0; +} + +static struct device_driver mpcore_wdt_driver = { + .name = "mpcore_wdt", + .bus = &platform_bus_type, + .probe = mpcore_wdt_probe, + .remove = __devexit_p(mpcore_wdt_remove), + .shutdown = mpcore_wdt_shutdown, +}; + +static char banner[] __initdata = KERN_INFO "MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n"; + +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); + printk(KERN_INFO "mpcore_margin value must be 0<mpcore_margin<65536, using %d\n", + TIMER_MARGIN); + } + + printk(banner, mpcore_noboot, mpcore_margin, nowayout); + + return driver_register(&mpcore_wdt_driver); +} + +static void __exit mpcore_wdt_exit(void) +{ + 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); |