diff options
Diffstat (limited to 'drivers/watchdog/wdt977.c')
| -rw-r--r-- | drivers/watchdog/wdt977.c | 506 |
1 files changed, 506 insertions, 0 deletions
diff --git a/drivers/watchdog/wdt977.c b/drivers/watchdog/wdt977.c new file mode 100644 index 0000000000..c9b8e863f7 --- /dev/null +++ b/drivers/watchdog/wdt977.c @@ -0,0 +1,506 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Wdt977 0.04: A Watchdog Device for Netwinder W83977AF chip + * + * (c) Copyright 1998 Rebel.com (Woody Suwalski <woody@netwinder.org>) + * + * ----------------------- + * + * ----------------------- + * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com> + * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT + * 19-Dec-2001 Woody Suwalski: Netwinder fixes, ioctl interface + * 06-Jan-2002 Woody Suwalski: For compatibility, convert all timeouts + * from minutes to seconds. + * 07-Jul-2003 Daniele Bellucci: Audit return code of misc_register in + * nwwatchdog_init. + * 25-Oct-2005 Woody Suwalski: Convert addresses to #defs, add spinlocks + * remove limitiation to be used on + * Netwinders only + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/init.h> +#include <linux/ioport.h> +#include <linux/watchdog.h> +#include <linux/notifier.h> +#include <linux/reboot.h> +#include <linux/io.h> +#include <linux/uaccess.h> + +#include <asm/mach-types.h> + +#define WATCHDOG_VERSION "0.04" +#define WATCHDOG_NAME "Wdt977" + +#define IO_INDEX_PORT 0x370 /* on some systems it can be 0x3F0 */ +#define IO_DATA_PORT (IO_INDEX_PORT + 1) + +#define UNLOCK_DATA 0x87 +#define LOCK_DATA 0xAA +#define DEVICE_REGISTER 0x07 + + +#define DEFAULT_TIMEOUT 60 /* default timeout in seconds */ + +static int timeout = DEFAULT_TIMEOUT; +static int timeoutM; /* timeout in minutes */ +static unsigned long timer_alive; +static int testmode; +static char expect_close; +static DEFINE_SPINLOCK(spinlock); + +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (60..15300, default=" + __MODULE_STRING(DEFAULT_TIMEOUT) ")"); +module_param(testmode, int, 0); +MODULE_PARM_DESC(testmode, "Watchdog testmode (1 = no reboot), default=0"); + +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) ")"); + +/* + * Start the watchdog + */ + +static int wdt977_start(void) +{ + unsigned long flags; + + spin_lock_irqsave(&spinlock, flags); + + /* unlock the SuperIO chip */ + outb_p(UNLOCK_DATA, IO_INDEX_PORT); + outb_p(UNLOCK_DATA, IO_INDEX_PORT); + + /* select device Aux2 (device=8) and set watchdog regs F2, F3 and F4 + * F2 has the timeout in minutes + * F3 could be set to the POWER LED blink (with GP17 set to PowerLed) + * at timeout, and to reset timer on kbd/mouse activity (not impl.) + * F4 is used to just clear the TIMEOUT'ed state (bit 0) + */ + outb_p(DEVICE_REGISTER, IO_INDEX_PORT); + outb_p(0x08, IO_DATA_PORT); + outb_p(0xF2, IO_INDEX_PORT); + outb_p(timeoutM, IO_DATA_PORT); + outb_p(0xF3, IO_INDEX_PORT); + outb_p(0x00, IO_DATA_PORT); /* another setting is 0E for + kbd/mouse/LED */ + outb_p(0xF4, IO_INDEX_PORT); + outb_p(0x00, IO_DATA_PORT); + + /* At last select device Aux1 (dev=7) and set GP16 as a + * watchdog output. In test mode watch the bit 1 on F4 to + * indicate "triggered" + */ + if (!testmode) { + outb_p(DEVICE_REGISTER, IO_INDEX_PORT); + outb_p(0x07, IO_DATA_PORT); + outb_p(0xE6, IO_INDEX_PORT); + outb_p(0x08, IO_DATA_PORT); + } + + /* lock the SuperIO chip */ + outb_p(LOCK_DATA, IO_INDEX_PORT); + + spin_unlock_irqrestore(&spinlock, flags); + pr_info("activated\n"); + + return 0; +} + +/* + * Stop the watchdog + */ + +static int wdt977_stop(void) +{ + unsigned long flags; + spin_lock_irqsave(&spinlock, flags); + + /* unlock the SuperIO chip */ + outb_p(UNLOCK_DATA, IO_INDEX_PORT); + outb_p(UNLOCK_DATA, IO_INDEX_PORT); + + /* select device Aux2 (device=8) and set watchdog regs F2,F3 and F4 + * F3 is reset to its default state + * F4 can clear the TIMEOUT'ed state (bit 0) - back to default + * We can not use GP17 as a PowerLed, as we use its usage as a RedLed + */ + outb_p(DEVICE_REGISTER, IO_INDEX_PORT); + outb_p(0x08, IO_DATA_PORT); + outb_p(0xF2, IO_INDEX_PORT); + outb_p(0xFF, IO_DATA_PORT); + outb_p(0xF3, IO_INDEX_PORT); + outb_p(0x00, IO_DATA_PORT); + outb_p(0xF4, IO_INDEX_PORT); + outb_p(0x00, IO_DATA_PORT); + outb_p(0xF2, IO_INDEX_PORT); + outb_p(0x00, IO_DATA_PORT); + + /* at last select device Aux1 (dev=7) and set + GP16 as a watchdog output */ + outb_p(DEVICE_REGISTER, IO_INDEX_PORT); + outb_p(0x07, IO_DATA_PORT); + outb_p(0xE6, IO_INDEX_PORT); + outb_p(0x08, IO_DATA_PORT); + + /* lock the SuperIO chip */ + outb_p(LOCK_DATA, IO_INDEX_PORT); + + spin_unlock_irqrestore(&spinlock, flags); + pr_info("shutdown\n"); + + return 0; +} + +/* + * Send a keepalive ping to the watchdog + * This is done by simply re-writing the timeout to reg. 0xF2 + */ + +static int wdt977_keepalive(void) +{ + unsigned long flags; + spin_lock_irqsave(&spinlock, flags); + + /* unlock the SuperIO chip */ + outb_p(UNLOCK_DATA, IO_INDEX_PORT); + outb_p(UNLOCK_DATA, IO_INDEX_PORT); + + /* select device Aux2 (device=8) and kicks watchdog reg F2 */ + /* F2 has the timeout in minutes */ + outb_p(DEVICE_REGISTER, IO_INDEX_PORT); + outb_p(0x08, IO_DATA_PORT); + outb_p(0xF2, IO_INDEX_PORT); + outb_p(timeoutM, IO_DATA_PORT); + + /* lock the SuperIO chip */ + outb_p(LOCK_DATA, IO_INDEX_PORT); + spin_unlock_irqrestore(&spinlock, flags); + + return 0; +} + +/* + * Set the watchdog timeout value + */ + +static int wdt977_set_timeout(int t) +{ + int tmrval; + + /* convert seconds to minutes, rounding up */ + tmrval = (t + 59) / 60; + + if (machine_is_netwinder()) { + /* we have a hw bug somewhere, so each 977 minute is actually + * only 30sec. This limits the max timeout to half of device + * max of 255 minutes... + */ + tmrval += tmrval; + } + + if (tmrval < 1 || tmrval > 255) + return -EINVAL; + + /* timeout is the timeout in seconds, timeoutM is + the timeout in minutes) */ + timeout = t; + timeoutM = tmrval; + return 0; +} + +/* + * Get the watchdog status + */ + +static int wdt977_get_status(int *status) +{ + int new_status; + unsigned long flags; + + spin_lock_irqsave(&spinlock, flags); + + /* unlock the SuperIO chip */ + outb_p(UNLOCK_DATA, IO_INDEX_PORT); + outb_p(UNLOCK_DATA, IO_INDEX_PORT); + + /* select device Aux2 (device=8) and read watchdog reg F4 */ + outb_p(DEVICE_REGISTER, IO_INDEX_PORT); + outb_p(0x08, IO_DATA_PORT); + outb_p(0xF4, IO_INDEX_PORT); + new_status = inb_p(IO_DATA_PORT); + + /* lock the SuperIO chip */ + outb_p(LOCK_DATA, IO_INDEX_PORT); + + spin_unlock_irqrestore(&spinlock, flags); + + *status = 0; + if (new_status & 1) + *status |= WDIOF_CARDRESET; + + return 0; +} + + +/* + * /dev/watchdog handling + */ + +static int wdt977_open(struct inode *inode, struct file *file) +{ + /* If the watchdog is alive we don't need to start it again */ + if (test_and_set_bit(0, &timer_alive)) + return -EBUSY; + + if (nowayout) + __module_get(THIS_MODULE); + + wdt977_start(); + return stream_open(inode, file); +} + +static int wdt977_release(struct inode *inode, struct file *file) +{ + /* + * Shut off the timer. + * Lock it in if it's a module and we set nowayout + */ + if (expect_close == 42) { + wdt977_stop(); + clear_bit(0, &timer_alive); + } else { + wdt977_keepalive(); + pr_crit("Unexpected close, not stopping watchdog!\n"); + } + expect_close = 0; + return 0; +} + + +/* + * wdt977_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 we don't define content meaning. + */ + +static ssize_t wdt977_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + if (count) { + if (!nowayout) { + size_t i; + + /* In case it was set long ago */ + expect_close = 0; + + for (i = 0; i != count; i++) { + char c; + if (get_user(c, buf + i)) + return -EFAULT; + if (c == 'V') + expect_close = 42; + } + } + + /* someone wrote to us, we should restart timer */ + wdt977_keepalive(); + } + return count; +} + +static const struct watchdog_info ident = { + .options = WDIOF_SETTIMEOUT | + WDIOF_MAGICCLOSE | + WDIOF_KEEPALIVEPING, + .firmware_version = 1, + .identity = WATCHDOG_NAME, +}; + +/* + * wdt977_ioctl: + * @inode: inode of the device + * @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 wdt977_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int status; + int new_options, retval = -EINVAL; + int new_timeout; + union { + struct watchdog_info __user *ident; + int __user *i; + } uarg; + + uarg.i = (int __user *)arg; + + switch (cmd) { + case WDIOC_GETSUPPORT: + return copy_to_user(uarg.ident, &ident, + sizeof(ident)) ? -EFAULT : 0; + + case WDIOC_GETSTATUS: + wdt977_get_status(&status); + return put_user(status, uarg.i); + + case WDIOC_GETBOOTSTATUS: + return put_user(0, uarg.i); + + case WDIOC_SETOPTIONS: + if (get_user(new_options, uarg.i)) + return -EFAULT; + + if (new_options & WDIOS_DISABLECARD) { + wdt977_stop(); + retval = 0; + } + + if (new_options & WDIOS_ENABLECARD) { + wdt977_start(); + retval = 0; + } + + return retval; + + case WDIOC_KEEPALIVE: + wdt977_keepalive(); + return 0; + + case WDIOC_SETTIMEOUT: + if (get_user(new_timeout, uarg.i)) + return -EFAULT; + + if (wdt977_set_timeout(new_timeout)) + return -EINVAL; + + wdt977_keepalive(); + fallthrough; + + case WDIOC_GETTIMEOUT: + return put_user(timeout, uarg.i); + + default: + return -ENOTTY; + + } +} + +static int wdt977_notify_sys(struct notifier_block *this, unsigned long code, + void *unused) +{ + if (code == SYS_DOWN || code == SYS_HALT) + wdt977_stop(); + return NOTIFY_DONE; +} + +static const struct file_operations wdt977_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = wdt977_write, + .unlocked_ioctl = wdt977_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .open = wdt977_open, + .release = wdt977_release, +}; + +static struct miscdevice wdt977_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &wdt977_fops, +}; + +static struct notifier_block wdt977_notifier = { + .notifier_call = wdt977_notify_sys, +}; + +static int __init wd977_init(void) +{ + int rc; + + pr_info("driver v%s\n", WATCHDOG_VERSION); + + /* Check that the timeout value is within its range; + if not reset to the default */ + if (wdt977_set_timeout(timeout)) { + wdt977_set_timeout(DEFAULT_TIMEOUT); + pr_info("timeout value must be 60 < timeout < 15300, using %d\n", + DEFAULT_TIMEOUT); + } + + /* on Netwinder the IOports are already reserved by + * arch/arm/mach-footbridge/netwinder-hw.c + */ + if (!machine_is_netwinder()) { + if (!request_region(IO_INDEX_PORT, 2, WATCHDOG_NAME)) { + pr_err("I/O address 0x%04x already in use\n", + IO_INDEX_PORT); + rc = -EIO; + goto err_out; + } + } + + rc = register_reboot_notifier(&wdt977_notifier); + if (rc) { + pr_err("cannot register reboot notifier (err=%d)\n", rc); + goto err_out_region; + } + + rc = misc_register(&wdt977_miscdev); + if (rc) { + pr_err("cannot register miscdev on minor=%d (err=%d)\n", + wdt977_miscdev.minor, rc); + goto err_out_reboot; + } + + pr_info("initialized. timeout=%d sec (nowayout=%d, testmode=%i)\n", + timeout, nowayout, testmode); + + return 0; + +err_out_reboot: + unregister_reboot_notifier(&wdt977_notifier); +err_out_region: + if (!machine_is_netwinder()) + release_region(IO_INDEX_PORT, 2); +err_out: + return rc; +} + +static void __exit wd977_exit(void) +{ + wdt977_stop(); + misc_deregister(&wdt977_miscdev); + unregister_reboot_notifier(&wdt977_notifier); + release_region(IO_INDEX_PORT, 2); +} + +module_init(wd977_init); +module_exit(wd977_exit); + +MODULE_AUTHOR("Woody Suwalski <woodys@xandros.com>"); +MODULE_DESCRIPTION("W83977AF Watchdog driver"); +MODULE_LICENSE("GPL"); |