+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * MachZ ZF-Logic Watchdog Timer driver for Linux
- *
- * The author does NOT admit liability nor provide warranty for
- * any of this software. This material is provided "AS-IS" in
- * the hope that it may be useful for others.
- *
- * Author: Fernando Fuganti <fuganti@conectiva.com.br>
- *
- * Based on sbc60xxwdt.c by Jakob Oestergaard
- *
- * We have two timers (wd#1, wd#2) driven by a 32 KHz clock with the
- * following periods:
- * wd#1 - 2 seconds;
- * wd#2 - 7.2 ms;
- * After the expiration of wd#1, it can generate a NMI, SCI, SMI, or
- * a system RESET and it starts wd#2 that unconditionally will RESET
- * the system when the counter reaches zero.
- *
- * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
- * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/types.h>
-#include <linux/timer.h>
-#include <linux/jiffies.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>
-
-
-/* ports */
-#define ZF_IOBASE 0x218
-#define INDEX 0x218
-#define DATA_B 0x219
-#define DATA_W 0x21A
-#define DATA_D 0x21A
-
-/* indexes */ /* size */
-#define ZFL_VERSION 0x02 /* 16 */
-#define CONTROL 0x10 /* 16 */
-#define STATUS 0x12 /* 8 */
-#define COUNTER_1 0x0C /* 16 */
-#define COUNTER_2 0x0E /* 8 */
-#define PULSE_LEN 0x0F /* 8 */
-
-/* controls */
-#define ENABLE_WD1 0x0001
-#define ENABLE_WD2 0x0002
-#define RESET_WD1 0x0010
-#define RESET_WD2 0x0020
-#define GEN_SCI 0x0100
-#define GEN_NMI 0x0200
-#define GEN_SMI 0x0400
-#define GEN_RESET 0x0800
-
-
-/* utilities */
-
-#define WD1 0
-#define WD2 1
-
-#define zf_writew(port, data) { outb(port, INDEX); outw(data, DATA_W); }
-#define zf_writeb(port, data) { outb(port, INDEX); outb(data, DATA_B); }
-#define zf_get_ZFL_version() zf_readw(ZFL_VERSION)
-
-
-static unsigned short zf_readw(unsigned char port)
-{
- outb(port, INDEX);
- return inw(DATA_W);
-}
-
-
-MODULE_AUTHOR("Fernando Fuganti <fuganti@conectiva.com.br>");
-MODULE_DESCRIPTION("MachZ ZF-Logic Watchdog driver");
-MODULE_LICENSE("GPL");
-
-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 PFX "machzwd"
-
-static const struct watchdog_info zf_info = {
- .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
- .firmware_version = 1,
- .identity = "ZF-Logic watchdog",
-};
-
-
-/*
- * action refers to action taken when watchdog resets
- * 0 = GEN_RESET
- * 1 = GEN_SMI
- * 2 = GEN_NMI
- * 3 = GEN_SCI
- * defaults to GEN_RESET (0)
- */
-static int action;
-module_param(action, int, 0);
-MODULE_PARM_DESC(action, "after watchdog resets, generate: "
- "0 = RESET(*) 1 = SMI 2 = NMI 3 = SCI");
-
-static void zf_ping(struct timer_list *unused);
-
-static int zf_action = GEN_RESET;
-static unsigned long zf_is_open;
-static char zf_expect_close;
-static DEFINE_SPINLOCK(zf_port_lock);
-static DEFINE_TIMER(zf_timer, zf_ping);
-static unsigned long next_heartbeat;
-
-
-/* timeout for user land heart beat (10 seconds) */
-#define ZF_USER_TIMEO (HZ*10)
-
-/* timeout for hardware watchdog (~500ms) */
-#define ZF_HW_TIMEO (HZ/2)
-
-/* number of ticks on WD#1 (driven by a 32KHz clock, 2s) */
-#define ZF_CTIMEOUT 0xffff
-
-#ifndef ZF_DEBUG
-#define dprintk(format, args...)
-#else
-#define dprintk(format, args...) \
- pr_debug(":%s:%d: " format, __func__, __LINE__ , ## args)
-#endif
-
-
-static inline void zf_set_status(unsigned char new)
-{
- zf_writeb(STATUS, new);
-}
-
-
-/* CONTROL register functions */
-
-static inline unsigned short zf_get_control(void)
-{
- return zf_readw(CONTROL);
-}
-
-static inline void zf_set_control(unsigned short new)
-{
- zf_writew(CONTROL, new);
-}
-
-
-/* WD#? counter functions */
-/*
- * Just set counter value
- */
-
-static inline void zf_set_timer(unsigned short new, unsigned char n)
-{
- switch (n) {
- case WD1:
- zf_writew(COUNTER_1, new);
- fallthrough;
- case WD2:
- zf_writeb(COUNTER_2, new > 0xff ? 0xff : new);
- fallthrough;
- default:
- return;
- }
-}
-
-/*
- * stop hardware timer
- */
-static void zf_timer_off(void)
-{
- unsigned int ctrl_reg = 0;
- unsigned long flags;
-
- /* stop internal ping */
- timer_delete_sync(&zf_timer);
-
- spin_lock_irqsave(&zf_port_lock, flags);
- /* stop watchdog timer */
- ctrl_reg = zf_get_control();
- ctrl_reg |= (ENABLE_WD1|ENABLE_WD2); /* disable wd1 and wd2 */
- ctrl_reg &= ~(ENABLE_WD1|ENABLE_WD2);
- zf_set_control(ctrl_reg);
- spin_unlock_irqrestore(&zf_port_lock, flags);
-
- pr_info("Watchdog timer is now disabled\n");
-}
-
-
-/*
- * start hardware timer
- */
-static void zf_timer_on(void)
-{
- unsigned int ctrl_reg = 0;
- unsigned long flags;
-
- spin_lock_irqsave(&zf_port_lock, flags);
-
- zf_writeb(PULSE_LEN, 0xff);
-
- zf_set_timer(ZF_CTIMEOUT, WD1);
-
- /* user land ping */
- next_heartbeat = jiffies + ZF_USER_TIMEO;
-
- /* start the timer for internal ping */
- mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
-
- /* start watchdog timer */
- ctrl_reg = zf_get_control();
- ctrl_reg |= (ENABLE_WD1|zf_action);
- zf_set_control(ctrl_reg);
- spin_unlock_irqrestore(&zf_port_lock, flags);
-
- pr_info("Watchdog timer is now enabled\n");
-}
-
-
-static void zf_ping(struct timer_list *unused)
-{
- unsigned int ctrl_reg = 0;
- unsigned long flags;
-
- zf_writeb(COUNTER_2, 0xff);
-
- if (time_before(jiffies, next_heartbeat)) {
- dprintk("time_before: %ld\n", next_heartbeat - jiffies);
- /*
- * reset event is activated by transition from 0 to 1 on
- * RESET_WD1 bit and we assume that it is already zero...
- */
-
- spin_lock_irqsave(&zf_port_lock, flags);
- ctrl_reg = zf_get_control();
- ctrl_reg |= RESET_WD1;
- zf_set_control(ctrl_reg);
-
- /* ...and nothing changes until here */
- ctrl_reg &= ~(RESET_WD1);
- zf_set_control(ctrl_reg);
- spin_unlock_irqrestore(&zf_port_lock, flags);
-
- mod_timer(&zf_timer, jiffies + ZF_HW_TIMEO);
- } else
- pr_crit("I will reset your machine\n");
-}
-
-static ssize_t zf_write(struct file *file, const char __user *buf, size_t count,
- loff_t *ppos)
-{
- /* See if we got the magic character */
- if (count) {
- /*
- * no need to check for close confirmation
- * no way to disable watchdog ;)
- */
- if (!nowayout) {
- size_t ofs;
- /*
- * note: just in case someone wrote the magic character
- * five months ago...
- */
- zf_expect_close = 0;
-
- /* now scan */
- for (ofs = 0; ofs != count; ofs++) {
- char c;
- if (get_user(c, buf + ofs))
- return -EFAULT;
- if (c == 'V') {
- zf_expect_close = 42;
- dprintk("zf_expect_close = 42\n");
- }
- }
- }
-
- /*
- * Well, anyhow someone wrote to us,
- * we should return that favour
- */
- next_heartbeat = jiffies + ZF_USER_TIMEO;
- dprintk("user ping at %ld\n", jiffies);
- }
- return count;
-}
-
-static long zf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
- void __user *argp = (void __user *)arg;
- int __user *p = argp;
- switch (cmd) {
- case WDIOC_GETSUPPORT:
- if (copy_to_user(argp, &zf_info, sizeof(zf_info)))
- return -EFAULT;
- break;
- case WDIOC_GETSTATUS:
- case WDIOC_GETBOOTSTATUS:
- return put_user(0, p);
- case WDIOC_KEEPALIVE:
- zf_ping(NULL);
- break;
- default:
- return -ENOTTY;
- }
- return 0;
-}
-
-static int zf_open(struct inode *inode, struct file *file)
-{
- if (test_and_set_bit(0, &zf_is_open))
- return -EBUSY;
- if (nowayout)
- __module_get(THIS_MODULE);
- zf_timer_on();
- return stream_open(inode, file);
-}
-
-static int zf_close(struct inode *inode, struct file *file)
-{
- if (zf_expect_close == 42)
- zf_timer_off();
- else {
- timer_delete(&zf_timer);
- pr_err("device file closed unexpectedly. Will not stop the WDT!\n");
- }
- clear_bit(0, &zf_is_open);
- zf_expect_close = 0;
- return 0;
-}
-
-/*
- * Notifier for system down
- */
-
-static int zf_notify_sys(struct notifier_block *this, unsigned long code,
- void *unused)
-{
- if (code == SYS_DOWN || code == SYS_HALT)
- zf_timer_off();
- return NOTIFY_DONE;
-}
-
-static const struct file_operations zf_fops = {
- .owner = THIS_MODULE,
- .write = zf_write,
- .unlocked_ioctl = zf_ioctl,
- .compat_ioctl = compat_ptr_ioctl,
- .open = zf_open,
- .release = zf_close,
-};
-
-static struct miscdevice zf_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &zf_fops,
-};
-
-
-/*
- * The device needs to learn about soft shutdowns in order to
- * turn the timebomb registers off.
- */
-static struct notifier_block zf_notifier = {
- .notifier_call = zf_notify_sys,
-};
-
-static void __init zf_show_action(int act)
-{
- static const char * const str[] = { "RESET", "SMI", "NMI", "SCI" };
-
- pr_info("Watchdog using action = %s\n", str[act]);
-}
-
-static int __init zf_init(void)
-{
- int ret;
-
- pr_info("MachZ ZF-Logic Watchdog driver initializing\n");
-
- ret = zf_get_ZFL_version();
- if (!ret || ret == 0xffff) {
- pr_warn("no ZF-Logic found\n");
- return -ENODEV;
- }
-
- if (action <= 3 && action >= 0)
- zf_action = zf_action >> action;
- else
- action = 0;
-
- zf_show_action(action);
-
- if (!request_region(ZF_IOBASE, 3, "MachZ ZFL WDT")) {
- pr_err("cannot reserve I/O ports at %d\n", ZF_IOBASE);
- ret = -EBUSY;
- goto no_region;
- }
-
- ret = register_reboot_notifier(&zf_notifier);
- if (ret) {
- pr_err("can't register reboot notifier (err=%d)\n", ret);
- goto no_reboot;
- }
-
- ret = misc_register(&zf_miscdev);
- if (ret) {
- pr_err("can't misc_register on minor=%d\n", WATCHDOG_MINOR);
- goto no_misc;
- }
-
- zf_set_status(0);
- zf_set_control(0);
-
- return 0;
-
-no_misc:
- unregister_reboot_notifier(&zf_notifier);
-no_reboot:
- release_region(ZF_IOBASE, 3);
-no_region:
- return ret;
-}
-
-
-static void __exit zf_exit(void)
-{
- zf_timer_off();
-
- misc_deregister(&zf_miscdev);
- unregister_reboot_notifier(&zf_notifier);
- release_region(ZF_IOBASE, 3);
-}
-
-module_init(zf_init);
-module_exit(zf_exit);
projects / thirdparty / linux.git / commitdiff
