--- /dev/null
+/*
+ * sma cpu5 watchdog driver
+ *
+ * Copyright (C) 2003 Heiko Ronsdorf <hero@ihg.uni-duisburg.de>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/ioport.h>
+#include <linux/timer.h>
+#include <linux/completion.h>
+#include <linux/jiffies.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+
+/* adjustable parameters */
+
+static int verbose;
+static int port = 0x91;
+static int ticks = 10000;
+static DEFINE_SPINLOCK(cpu5wdt_lock);
+
+#define PFX "cpu5wdt: "
+
+#define CPU5WDT_EXTENT 0x0A
+
+#define CPU5WDT_STATUS_REG 0x00
+#define CPU5WDT_TIME_A_REG 0x02
+#define CPU5WDT_TIME_B_REG 0x03
+#define CPU5WDT_MODE_REG 0x04
+#define CPU5WDT_TRIGGER_REG 0x07
+#define CPU5WDT_ENABLE_REG 0x08
+#define CPU5WDT_RESET_REG 0x09
+
+#define CPU5WDT_INTERVAL (HZ/10+1)
+
+/* some device data */
+
+static struct {
+ struct completion stop;
+ int running;
+ struct timer_list timer;
+ int queue;
+ int default_ticks;
+ unsigned long inuse;
+} cpu5wdt_device;
+
+/* generic helper functions */
+
+static void cpu5wdt_trigger(unsigned long unused)
+{
+ if (verbose > 2)
+ pr_debug("trigger at %i ticks\n", ticks);
+
+ if (cpu5wdt_device.running)
+ ticks--;
+
+ spin_lock(&cpu5wdt_lock);
+ /* keep watchdog alive */
+ outb(1, port + CPU5WDT_TRIGGER_REG);
+
+ /* requeue?? */
+ if (cpu5wdt_device.queue && ticks)
+ mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
+ else {
+ /* ticks doesn't matter anyway */
+ complete(&cpu5wdt_device.stop);
+ }
+ spin_unlock(&cpu5wdt_lock);
+
+}
+
+static void cpu5wdt_reset(void)
+{
+ ticks = cpu5wdt_device.default_ticks;
+
+ if (verbose)
+ pr_debug("reset (%i ticks)\n", (int) ticks);
+
+}
+
+static void cpu5wdt_start(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&cpu5wdt_lock, flags);
+ if (!cpu5wdt_device.queue) {
+ cpu5wdt_device.queue = 1;
+ outb(0, port + CPU5WDT_TIME_A_REG);
+ outb(0, port + CPU5WDT_TIME_B_REG);
+ outb(1, port + CPU5WDT_MODE_REG);
+ outb(0, port + CPU5WDT_RESET_REG);
+ outb(0, port + CPU5WDT_ENABLE_REG);
+ mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
+ }
+ /* if process dies, counter is not decremented */
+ cpu5wdt_device.running++;
+ spin_unlock_irqrestore(&cpu5wdt_lock, flags);
+}
+
+static int cpu5wdt_stop(void)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&cpu5wdt_lock, flags);
+ if (cpu5wdt_device.running)
+ cpu5wdt_device.running = 0;
+ ticks = cpu5wdt_device.default_ticks;
+ spin_unlock_irqrestore(&cpu5wdt_lock, flags);
+ if (verbose)
+ pr_crit("stop not possible\n");
+ return -EIO;
+}
+
+/* filesystem operations */
+
+static int cpu5wdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &cpu5wdt_device.inuse))
+ return -EBUSY;
+ return nonseekable_open(inode, file);
+}
+
+static int cpu5wdt_release(struct inode *inode, struct file *file)
+{
+ clear_bit(0, &cpu5wdt_device.inuse);
+ return 0;
+}
+
+static long cpu5wdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ unsigned int value;
+ static const struct watchdog_info ident = {
+ .options = WDIOF_CARDRESET,
+ .identity = "CPU5 WDT",
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &ident, sizeof(ident)))
+ return -EFAULT;
+ break;
+ case WDIOC_GETSTATUS:
+ value = inb(port + CPU5WDT_STATUS_REG);
+ value = (value >> 2) & 1;
+ return put_user(value, p);
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+ case WDIOC_SETOPTIONS:
+ if (get_user(value, p))
+ return -EFAULT;
+ if (value & WDIOS_ENABLECARD)
+ cpu5wdt_start();
+ if (value & WDIOS_DISABLECARD)
+ cpu5wdt_stop();
+ break;
+ case WDIOC_KEEPALIVE:
+ cpu5wdt_reset();
+ break;
+ default:
+ return -ENOTTY;
+ }
+ return 0;
+}
+
+static ssize_t cpu5wdt_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ if (!count)
+ return -EIO;
+ cpu5wdt_reset();
+ return count;
+}
+
+static const struct file_operations cpu5wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .unlocked_ioctl = cpu5wdt_ioctl,
+ .open = cpu5wdt_open,
+ .write = cpu5wdt_write,
+ .release = cpu5wdt_release,
+};
+
+static struct miscdevice cpu5wdt_misc = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &cpu5wdt_fops,
+};
+
+/* init/exit function */
+
+static int cpu5wdt_init(void)
+{
+ unsigned int val;
+ int err;
+
+ if (verbose)
+ pr_debug("port=0x%x, verbose=%i\n", port, verbose);
+
+ init_completion(&cpu5wdt_device.stop);
+ cpu5wdt_device.queue = 0;
+ setup_timer(&cpu5wdt_device.timer, cpu5wdt_trigger, 0);
+ cpu5wdt_device.default_ticks = ticks;
+
+ if (!request_region(port, CPU5WDT_EXTENT, PFX)) {
+ pr_err("request_region failed\n");
+ err = -EBUSY;
+ goto no_port;
+ }
+
+ /* watchdog reboot? */
+ val = inb(port + CPU5WDT_STATUS_REG);
+ val = (val >> 2) & 1;
+ if (!val)
+ pr_info("sorry, was my fault\n");
+
+ err = misc_register(&cpu5wdt_misc);
+ if (err < 0) {
+ pr_err("misc_register failed\n");
+ goto no_misc;
+ }
+
+
+ pr_info("init success\n");
+ return 0;
+
+no_misc:
+ release_region(port, CPU5WDT_EXTENT);
+no_port:
+ return err;
+}
+
+static int cpu5wdt_init_module(void)
+{
+ return cpu5wdt_init();
+}
+
+static void cpu5wdt_exit(void)
+{
+ if (cpu5wdt_device.queue) {
+ cpu5wdt_device.queue = 0;
+ wait_for_completion(&cpu5wdt_device.stop);
+ del_timer(&cpu5wdt_device.timer);
+ }
+
+ misc_deregister(&cpu5wdt_misc);
+
+ release_region(port, CPU5WDT_EXTENT);
+
+}
+
+static void cpu5wdt_exit_module(void)
+{
+ cpu5wdt_exit();
+}
+
+/* module entry points */
+
+module_init(cpu5wdt_init_module);
+module_exit(cpu5wdt_exit_module);
+
+MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>");
+MODULE_DESCRIPTION("sma cpu5 watchdog driver");
+MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog");
+MODULE_LICENSE("GPL");
+
+module_param(port, int, 0);
+MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
+
+module_param(verbose, int, 0);
+MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
+
+module_param(ticks, int, 0);
+MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");
Code Review / kvmfornfv.git / blobdiff