--- /dev/null
+/*
+ * 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@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>*
+ */
+
+/* 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.
+ */
+
+#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 <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+static unsigned long eurwdt_is_open;
+static int eurwdt_timeout;
+static char eur_expect_close;
+
+/*
+ * You must set these - there is no sane way to probe for this board.
+ * You can use eurwdt=x,y to set these now.
+ */
+
+static int io = 0x3f0;
+static int irq = 10;
+static char *ev = "int";
+
+#define WDT_TIMEOUT 60 /* 1 minute */
+
+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) ")");
+
+/*
+ * 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(io, int, 0);
+MODULE_PARM_DESC(io, "Eurotech WDT io port (default=0x3f0)");
+module_param(irq, int, 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) {
+ printk(KERN_ERR ": invalid irq number\n");
+ irq = 0; /* if invalid we disable interrupt */
+ }
+ if (irq == 0)
+ printk(KERN_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)
+{
+ printk(KERN_CRIT "timeout WDT timeout\n");
+
+#ifdef ONLY_TESTING
+ printk(KERN_CRIT "Would Reboot.\n");
+#else
+ printk(KERN_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 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;
+ }
+ }
+ eurwdt_ping(); /* the default timeout */
+ }
+
+ return count;
+}
+
+/**
+ * eurwdt_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 int eurwdt_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ static 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) {
+ default:
+ return -ENOTTY;
+
+ 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_KEEPALIVE:
+ eurwdt_ping();
+ return 0;
+
+ case WDIOC_SETTIMEOUT:
+ if (copy_from_user(&time, p, sizeof(int)))
+ return -EFAULT;
+
+ /* Sanity check */
+ if (time < 0 || time > 255)
+ return -EINVAL;
+
+ eurwdt_timeout = time;
+ eurwdt_set_timeout(time);
+ /* Fall */
+
+ case WDIOC_GETTIMEOUT:
+ return put_user(eurwdt_timeout, p);
+
+ case WDIOC_SETOPTIONS:
+ if (get_user(options, p))
+ return -EFAULT;
+ if (options & WDIOS_DISABLECARD) {
+ eurwdt_disable_timer();
+ retval = 0;
+ }
+ if (options & WDIOS_ENABLECARD) {
+ eurwdt_activate_timer();
+ eurwdt_ping();
+ retval = 0;
+ }
+ return retval;
+ }
+}
+
+/**
+ * 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 nonseekable_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 {
+ printk(KERN_CRIT "eurwdt: 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) {
+ /* Turn the card off */
+ eurwdt_disable_timer();
+ }
+
+ return NOTIFY_DONE;
+}
+
+/*
+ * Kernel Interfaces
+ */
+
+
+static const struct file_operations eurwdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = eurwdt_write,
+ .ioctl = eurwdt_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,
+};
+
+/**
+ * cleanup_module:
+ *
+ * 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, IRQF_DISABLED, "eurwdt", NULL);
+ if(ret) {
+ printk(KERN_ERR "eurwdt: IRQ %d is not free.\n", irq);
+ goto out;
+ }
+
+ if (!request_region(io, 2, "eurwdt")) {
+ printk(KERN_ERR "eurwdt: IO %X is not free.\n", io);
+ ret = -EBUSY;
+ goto outirq;
+ }
+
+ ret = register_reboot_notifier(&eurwdt_notifier);
+ if (ret) {
+ printk(KERN_ERR "eurwdt: can't register reboot notifier (err=%d)\n", ret);
+ goto outreg;
+ }
+
+ ret = misc_register(&eurwdt_miscdev);
+ if (ret) {
+ printk(KERN_ERR "eurwdt: can't misc_register on minor=%d\n",
+ WATCHDOG_MINOR);
+ goto outreboot;
+ }
+
+ eurwdt_unlock_chip();
+
+ ret = 0;
+ printk(KERN_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");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
projects / firefly-linux-kernel-4.4.55.git / blobdiff