--- /dev/null
+/*
+ * Advantech Single Board Computer WDT driver
+ *
+ * (c) Copyright 2000-2001 Marek Michalkiewicz <marekm@linux.org.pl>
+ *
+ * Based on acquirewdt.c which is based on wdt.c.
+ * Original copyright messages:
+ *
+ * (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ * All Rights Reserved.
+ *
+ * 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>
+ *
+ * 14-Dec-2001 Matt Domsch <Matt_Domsch@dell.com>
+ * Added nowayout module option to override CONFIG_WATCHDOG_NOWAYOUT
+ *
+ * 16-Oct-2002 Rob Radez <rob@osinvestor.com>
+ * Clean up ioctls, clean up init + exit, add expect close support,
+ * add wdt_start and wdt_stop as parameters.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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/platform_device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+
+#define DRV_NAME "advantechwdt"
+#define WATCHDOG_NAME "Advantech WDT"
+#define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
+
+/* the watchdog platform device */
+static struct platform_device *advwdt_platform_device;
+static unsigned long advwdt_is_open;
+static char adv_expect_close;
+
+/*
+ * You must set these - there is no sane way to probe for this board.
+ *
+ * To enable or restart, write the timeout value in seconds (1 to 63)
+ * to I/O port wdt_start. To disable, read I/O port wdt_stop.
+ * Both are 0x443 for most boards (tested on a PCA-6276VE-00B1), but
+ * check your manual (at least the PCA-6159 seems to be different -
+ * the manual says wdt_stop is 0x43, not 0x443).
+ * (0x43 is also a write-only control register for the 8254 timer!)
+ */
+
+static int wdt_stop = 0x443;
+module_param(wdt_stop, int, 0);
+MODULE_PARM_DESC(wdt_stop, "Advantech WDT 'stop' io port (default 0x443)");
+
+static int wdt_start = 0x443;
+module_param(wdt_start, int, 0);
+MODULE_PARM_DESC(wdt_start, "Advantech WDT 'start' io port (default 0x443)");
+
+static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in seconds. 1<= timeout <=63, default="
+ __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
+
+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) ")");
+
+/*
+ * Watchdog Operations
+ */
+
+static void advwdt_ping(void)
+{
+ /* Write a watchdog value */
+ outb_p(timeout, wdt_start);
+}
+
+static void advwdt_disable(void)
+{
+ inb_p(wdt_stop);
+}
+
+static int advwdt_set_heartbeat(int t)
+{
+ if (t < 1 || t > 63)
+ return -EINVAL;
+ timeout = t;
+ return 0;
+}
+
+/*
+ * /dev/watchdog handling
+ */
+
+static ssize_t advwdt_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ if (count) {
+ if (!nowayout) {
+ size_t i;
+
+ adv_expect_close = 0;
+
+ for (i = 0; i != count; i++) {
+ char c;
+ if (get_user(c, buf + i))
+ return -EFAULT;
+ if (c == 'V')
+ adv_expect_close = 42;
+ }
+ }
+ advwdt_ping();
+ }
+ return count;
+}
+
+static long advwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ int new_timeout;
+ 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 = WATCHDOG_NAME,
+ };
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &ident, sizeof(ident)))
+ return -EFAULT;
+ break;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+
+ case WDIOC_SETOPTIONS:
+ {
+ int options, retval = -EINVAL;
+
+ if (get_user(options, p))
+ return -EFAULT;
+ if (options & WDIOS_DISABLECARD) {
+ advwdt_disable();
+ retval = 0;
+ }
+ if (options & WDIOS_ENABLECARD) {
+ advwdt_ping();
+ retval = 0;
+ }
+ return retval;
+ }
+ case WDIOC_KEEPALIVE:
+ advwdt_ping();
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_timeout, p))
+ return -EFAULT;
+ if (advwdt_set_heartbeat(new_timeout))
+ return -EINVAL;
+ advwdt_ping();
+ /* Fall */
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, p);
+ default:
+ return -ENOTTY;
+ }
+ return 0;
+}
+
+static int advwdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &advwdt_is_open))
+ return -EBUSY;
+ /*
+ * Activate
+ */
+
+ advwdt_ping();
+ return nonseekable_open(inode, file);
+}
+
+static int advwdt_close(struct inode *inode, struct file *file)
+{
+ if (adv_expect_close == 42) {
+ advwdt_disable();
+ } else {
+ pr_crit("Unexpected close, not stopping watchdog!\n");
+ advwdt_ping();
+ }
+ clear_bit(0, &advwdt_is_open);
+ adv_expect_close = 0;
+ return 0;
+}
+
+/*
+ * Kernel Interfaces
+ */
+
+static const struct file_operations advwdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = advwdt_write,
+ .unlocked_ioctl = advwdt_ioctl,
+ .open = advwdt_open,
+ .release = advwdt_close,
+};
+
+static struct miscdevice advwdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &advwdt_fops,
+};
+
+/*
+ * Init & exit routines
+ */
+
+static int __init advwdt_probe(struct platform_device *dev)
+{
+ int ret;
+
+ if (wdt_stop != wdt_start) {
+ if (!request_region(wdt_stop, 1, WATCHDOG_NAME)) {
+ pr_err("I/O address 0x%04x already in use\n",
+ wdt_stop);
+ ret = -EIO;
+ goto out;
+ }
+ }
+
+ if (!request_region(wdt_start, 1, WATCHDOG_NAME)) {
+ pr_err("I/O address 0x%04x already in use\n", wdt_start);
+ ret = -EIO;
+ goto unreg_stop;
+ }
+
+ /* Check that the heartbeat value is within it's range ;
+ * if not reset to the default */
+ if (advwdt_set_heartbeat(timeout)) {
+ advwdt_set_heartbeat(WATCHDOG_TIMEOUT);
+ pr_info("timeout value must be 1<=x<=63, using %d\n", timeout);
+ }
+
+ ret = misc_register(&advwdt_miscdev);
+ if (ret != 0) {
+ pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, ret);
+ goto unreg_regions;
+ }
+ pr_info("initialized. timeout=%d sec (nowayout=%d)\n",
+ timeout, nowayout);
+out:
+ return ret;
+unreg_regions:
+ release_region(wdt_start, 1);
+unreg_stop:
+ if (wdt_stop != wdt_start)
+ release_region(wdt_stop, 1);
+ goto out;
+}
+
+static int advwdt_remove(struct platform_device *dev)
+{
+ misc_deregister(&advwdt_miscdev);
+ release_region(wdt_start, 1);
+ if (wdt_stop != wdt_start)
+ release_region(wdt_stop, 1);
+
+ return 0;
+}
+
+static void advwdt_shutdown(struct platform_device *dev)
+{
+ /* Turn the WDT off if we have a soft shutdown */
+ advwdt_disable();
+}
+
+static struct platform_driver advwdt_driver = {
+ .remove = advwdt_remove,
+ .shutdown = advwdt_shutdown,
+ .driver = {
+ .name = DRV_NAME,
+ },
+};
+
+static int __init advwdt_init(void)
+{
+ int err;
+
+ pr_info("WDT driver for Advantech single board computer initialising\n");
+
+ advwdt_platform_device = platform_device_register_simple(DRV_NAME,
+ -1, NULL, 0);
+ if (IS_ERR(advwdt_platform_device))
+ return PTR_ERR(advwdt_platform_device);
+
+ err = platform_driver_probe(&advwdt_driver, advwdt_probe);
+ if (err)
+ goto unreg_platform_device;
+
+ return 0;
+
+unreg_platform_device:
+ platform_device_unregister(advwdt_platform_device);
+ return err;
+}
+
+static void __exit advwdt_exit(void)
+{
+ platform_device_unregister(advwdt_platform_device);
+ platform_driver_unregister(&advwdt_driver);
+ pr_info("Watchdog Module Unloaded\n");
+}
+
+module_init(advwdt_init);
+module_exit(advwdt_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marek Michalkiewicz <marekm@linux.org.pl>");
+MODULE_DESCRIPTION("Advantech Single Board Computer WDT driver");
Code Review / kvmfornfv.git / blobdiff