diff options
Diffstat (limited to 'drivers/watchdog/eurotechwdt.c')
| -rw-r--r-- | drivers/watchdog/eurotechwdt.c | 476 |
1 files changed, 476 insertions, 0 deletions
diff --git a/drivers/watchdog/eurotechwdt.c b/drivers/watchdog/eurotechwdt.c new file mode 100644 index 0000000000..e26609ad4c --- /dev/null +++ b/drivers/watchdog/eurotechwdt.c @@ -0,0 +1,476 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Eurotech CPU-1220/1410/1420 on board WDT driver + * + * (c) Copyright 2001 Ascensit <support@ascensit.com> + * (c) Copyright 2001 Rodolfo Giometti <giometti@ascensit.com> + * (c) Copyright 2002 Rob Radez <rob@osinvestor.com> + * + * Based on wdt.c. + * Original copyright messages: + * + * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>, + * All Rights Reserved. + * + * 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>* + */ + +/* Changelog: + * + * 2001 - Rodolfo Giometti + * Initial release + * + * 2002/04/25 - Rob Radez + * clean up #includes + * clean up locking + * make __setup param unique + * proper options in watchdog_info + * add WDIOC_GETSTATUS and WDIOC_SETOPTIONS ioctls + * add expect_close support + * + * 2002.05.30 - Joel Becker <joel.becker@oracle.com> + * Added Matt Domsch's nowayout module option. + */ + +/* + * The eurotech CPU-1220/1410/1420's watchdog is a part + * of the on-board SUPER I/O device SMSC FDC 37B782. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/interrupt.h> +#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/ioport.h> +#include <linux/notifier.h> +#include <linux/reboot.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/uaccess.h> + + +static unsigned long eurwdt_is_open; +static int eurwdt_timeout; +static char eur_expect_close; +static DEFINE_SPINLOCK(eurwdt_lock); + +/* + * You must set these - there is no sane way to probe for this board. + */ + +static int io = 0x3f0; +static int irq = 10; +static char *ev = "int"; + +#define WDT_TIMEOUT 60 /* 1 minute */ + +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) ")"); + +/* + * Some symbolic names + */ + +#define WDT_CTRL_REG 0x30 +#define WDT_OUTPIN_CFG 0xe2 +#define WDT_EVENT_INT 0x00 +#define WDT_EVENT_REBOOT 0x08 +#define WDT_UNIT_SEL 0xf1 +#define WDT_UNIT_SECS 0x80 +#define WDT_TIMEOUT_VAL 0xf2 +#define WDT_TIMER_CFG 0xf3 + + +module_param_hw(io, int, ioport, 0); +MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)"); +module_param_hw(irq, int, irq, 0); +MODULE_PARM_DESC(irq, "Eurotech WDT irq (default=10)"); +module_param(ev, charp, 0); +MODULE_PARM_DESC(ev, "Eurotech WDT event type (default is `int')"); + + +/* + * Programming support + */ + +static inline void eurwdt_write_reg(u8 index, u8 data) +{ + outb(index, io); + outb(data, io+1); +} + +static inline void eurwdt_lock_chip(void) +{ + outb(0xaa, io); +} + +static inline void eurwdt_unlock_chip(void) +{ + outb(0x55, io); + eurwdt_write_reg(0x07, 0x08); /* set the logical device */ +} + +static inline void eurwdt_set_timeout(int timeout) +{ + eurwdt_write_reg(WDT_TIMEOUT_VAL, (u8) timeout); +} + +static inline void eurwdt_disable_timer(void) +{ + eurwdt_set_timeout(0); +} + +static void eurwdt_activate_timer(void) +{ + eurwdt_disable_timer(); + eurwdt_write_reg(WDT_CTRL_REG, 0x01); /* activate the WDT */ + eurwdt_write_reg(WDT_OUTPIN_CFG, + !strcmp("int", ev) ? WDT_EVENT_INT : WDT_EVENT_REBOOT); + + /* Setting interrupt line */ + if (irq == 2 || irq > 15 || irq < 0) { + pr_err("invalid irq number\n"); + irq = 0; /* if invalid we disable interrupt */ + } + if (irq == 0) + pr_info("interrupt disabled\n"); + + eurwdt_write_reg(WDT_TIMER_CFG, irq << 4); + + eurwdt_write_reg(WDT_UNIT_SEL, WDT_UNIT_SECS); /* we use seconds */ + eurwdt_set_timeout(0); /* the default timeout */ +} + + +/* + * Kernel methods. + */ + +static irqreturn_t eurwdt_interrupt(int irq, void *dev_id) +{ + pr_crit("timeout WDT timeout\n"); + +#ifdef ONLY_TESTING + pr_crit("Would Reboot\n"); +#else + pr_crit("Initiating system reboot\n"); + emergency_restart(); +#endif + return IRQ_HANDLED; +} + + +/** + * eurwdt_ping: + * + * Reload counter one with the watchdog timeout. + */ + +static void eurwdt_ping(void) +{ + /* Write the watchdog default value */ + eurwdt_set_timeout(eurwdt_timeout); +} + +/** + * eurwdt_write: + * @file: file handle to the watchdog + * @buf: buffer to write (unused as data does not matter here + * @count: count of bytes + * @ppos: pointer to the position to write. No seeks allowed + * + * A write to a watchdog device is defined as a keepalive signal. Any + * write of data will do, as we don't define content meaning. + */ + +static ssize_t eurwdt_write(struct file *file, const char __user *buf, +size_t count, loff_t *ppos) +{ + if (count) { + if (!nowayout) { + size_t i; + + eur_expect_close = 0; + + for (i = 0; i != count; i++) { + char c; + if (get_user(c, buf + i)) + return -EFAULT; + if (c == 'V') + eur_expect_close = 42; + } + } + spin_lock(&eurwdt_lock); + eurwdt_ping(); /* the default timeout */ + spin_unlock(&eurwdt_lock); + } + return count; +} + +/** + * eurwdt_ioctl: + * @file: file handle to the device + * @cmd: watchdog command + * @arg: argument pointer + * + * The watchdog API defines a common set of functions for all watchdogs + * according to their available features. + */ + +static long eurwdt_ioctl(struct file *file, + unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int __user *p = argp; + static const struct watchdog_info ident = { + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT + | WDIOF_MAGICCLOSE, + .firmware_version = 1, + .identity = "WDT Eurotech CPU-1220/1410", + }; + + int time; + int options, retval = -EINVAL; + + switch (cmd) { + case WDIOC_GETSUPPORT: + return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + return put_user(0, p); + + case WDIOC_SETOPTIONS: + if (get_user(options, p)) + return -EFAULT; + spin_lock(&eurwdt_lock); + if (options & WDIOS_DISABLECARD) { + eurwdt_disable_timer(); + retval = 0; + } + if (options & WDIOS_ENABLECARD) { + eurwdt_activate_timer(); + eurwdt_ping(); + retval = 0; + } + spin_unlock(&eurwdt_lock); + return retval; + + case WDIOC_KEEPALIVE: + spin_lock(&eurwdt_lock); + eurwdt_ping(); + spin_unlock(&eurwdt_lock); + return 0; + + case WDIOC_SETTIMEOUT: + if (copy_from_user(&time, p, sizeof(int))) + return -EFAULT; + + /* Sanity check */ + if (time < 0 || time > 255) + return -EINVAL; + + spin_lock(&eurwdt_lock); + eurwdt_timeout = time; + eurwdt_set_timeout(time); + spin_unlock(&eurwdt_lock); + fallthrough; + + case WDIOC_GETTIMEOUT: + return put_user(eurwdt_timeout, p); + + default: + return -ENOTTY; + } +} + +/** + * eurwdt_open: + * @inode: inode of device + * @file: file handle to device + * + * The misc device has been opened. The watchdog device is single + * open and on opening we load the counter. + */ + +static int eurwdt_open(struct inode *inode, struct file *file) +{ + if (test_and_set_bit(0, &eurwdt_is_open)) + return -EBUSY; + eurwdt_timeout = WDT_TIMEOUT; /* initial timeout */ + /* Activate the WDT */ + eurwdt_activate_timer(); + return stream_open(inode, file); +} + +/** + * eurwdt_release: + * @inode: inode to board + * @file: file handle to board + * + * The watchdog has a configurable API. There is a religious dispute + * between people who want their watchdog to be able to shut down and + * those who want to be sure if the watchdog manager dies the machine + * reboots. In the former case we disable the counters, in the latter + * case you have to open it again very soon. + */ + +static int eurwdt_release(struct inode *inode, struct file *file) +{ + if (eur_expect_close == 42) + eurwdt_disable_timer(); + else { + pr_crit("Unexpected close, not stopping watchdog!\n"); + eurwdt_ping(); + } + clear_bit(0, &eurwdt_is_open); + eur_expect_close = 0; + return 0; +} + +/** + * eurwdt_notify_sys: + * @this: our notifier block + * @code: the event being reported + * @unused: unused + * + * Our notifier is called on system shutdowns. We want to turn the card + * off at reboot otherwise the machine will reboot again during memory + * test or worse yet during the following fsck. This would suck, in fact + * trust me - if it happens it does suck. + */ + +static int eurwdt_notify_sys(struct notifier_block *this, unsigned long code, + void *unused) +{ + if (code == SYS_DOWN || code == SYS_HALT) + eurwdt_disable_timer(); /* Turn the card off */ + + return NOTIFY_DONE; +} + +/* + * Kernel Interfaces + */ + + +static const struct file_operations eurwdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = eurwdt_write, + .unlocked_ioctl = eurwdt_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .open = eurwdt_open, + .release = eurwdt_release, +}; + +static struct miscdevice eurwdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &eurwdt_fops, +}; + +/* + * The WDT card needs to learn about soft shutdowns in order to + * turn the timebomb registers off. + */ + +static struct notifier_block eurwdt_notifier = { + .notifier_call = eurwdt_notify_sys, +}; + +/** + * eurwdt_exit: + * + * Unload the watchdog. You cannot do this with any file handles open. + * If your watchdog is set to continue ticking on close and you unload + * it, well it keeps ticking. We won't get the interrupt but the board + * will not touch PC memory so all is fine. You just have to load a new + * module in 60 seconds or reboot. + */ + +static void __exit eurwdt_exit(void) +{ + eurwdt_lock_chip(); + + misc_deregister(&eurwdt_miscdev); + + unregister_reboot_notifier(&eurwdt_notifier); + release_region(io, 2); + free_irq(irq, NULL); +} + +/** + * eurwdt_init: + * + * Set up the WDT watchdog board. After grabbing the resources + * we require we need also to unlock the device. + * The open() function will actually kick the board off. + */ + +static int __init eurwdt_init(void) +{ + int ret; + + ret = request_irq(irq, eurwdt_interrupt, 0, "eurwdt", NULL); + if (ret) { + pr_err("IRQ %d is not free\n", irq); + goto out; + } + + if (!request_region(io, 2, "eurwdt")) { + pr_err("IO %X is not free\n", io); + ret = -EBUSY; + goto outirq; + } + + ret = register_reboot_notifier(&eurwdt_notifier); + if (ret) { + pr_err("can't register reboot notifier (err=%d)\n", ret); + goto outreg; + } + + ret = misc_register(&eurwdt_miscdev); + if (ret) { + pr_err("can't misc_register on minor=%d\n", WATCHDOG_MINOR); + goto outreboot; + } + + eurwdt_unlock_chip(); + + ret = 0; + pr_info("Eurotech WDT driver 0.01 at %X (Interrupt %d) - timeout event: %s\n", + io, irq, (!strcmp("int", ev) ? "int" : "reboot")); + +out: + return ret; + +outreboot: + unregister_reboot_notifier(&eurwdt_notifier); + +outreg: + release_region(io, 2); + +outirq: + free_irq(irq, NULL); + goto out; +} + +module_init(eurwdt_init); +module_exit(eurwdt_exit); + +MODULE_AUTHOR("Rodolfo Giometti"); +MODULE_DESCRIPTION("Driver for Eurotech CPU-1220/1410 on board watchdog"); +MODULE_LICENSE("GPL"); |