Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 384 insertions, 0 deletions

diff --git a/drivers/watchdog/sbc60xxwdt.c b/drivers/watchdog/sbc60xxwdt.c
new file mode 100644
index 000000000..7b974802d
--- /dev/null
+++ b/drivers/watchdog/sbc60xxwdt.c
@@ -0,0 +1,384 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	60xx Single Board Computer Watchdog Timer driver for Linux 2.2.x
+ *
+ *	Based on acquirewdt.c by Alan Cox.
+ *
+ *	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.
+ *
+ *	(c) Copyright 2000    Jakob Oestergaard <jakob@unthought.net>
+ *
+ *           12/4 - 2000      [Initial revision]
+ *           25/4 - 2000      Added /dev/watchdog support
+ *           09/5 - 2001      [smj@oro.net] fixed fop_write to "return 1"
+ *					on success
+ *           12/4 - 2002      [rob@osinvestor.com] eliminate fop_read
+ *                            fix possible wdt_is_open race
+ *                            add CONFIG_WATCHDOG_NOWAYOUT support
+ *                            remove lock_kernel/unlock_kernel pairs
+ *                            added KERN_* to printk's
+ *                            got rid of extraneous comments
+ *                            changed watchdog_info to correctly reflect what
+ *			      the driver offers
+ *			      added WDIOC_GETSTATUS, WDIOC_GETBOOTSTATUS,
+ *			      WDIOC_SETTIMEOUT, WDIOC_GETTIMEOUT, and
+ *			      WDIOC_SETOPTIONS ioctls
+ *           09/8 - 2003      [wim@iguana.be] cleanup of trailing spaces
+ *                            use module_param
+ *                            made timeout (the emulated heartbeat) a
+ *			      module_param
+ *                            made the keepalive ping an internal subroutine
+ *                            made wdt_stop and wdt_start module params
+ *                            added extra printk's for startup problems
+ *                            added MODULE_AUTHOR and MODULE_DESCRIPTION info
+ *
+ *  This WDT driver is different from the other Linux WDT
+ *  drivers in the following ways:
+ *  *)  The driver will ping the watchdog by itself, because this
+ *      particular WDT has a very short timeout (one second) and it
+ *      would be insane to count on any userspace daemon always
+ *      getting scheduled within that time frame.
+ */
+
+#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>
+
+
+#define OUR_NAME "sbc60xxwdt"
+#define PFX OUR_NAME ": "
+
+/*
+ * You must set these - The driver cannot probe for the settings
+ */
+
+static int wdt_stop = 0x45;
+module_param(wdt_stop, int, 0);
+MODULE_PARM_DESC(wdt_stop, "SBC60xx WDT 'stop' io port (default 0x45)");
+
+static int wdt_start = 0x443;
+module_param(wdt_start, int, 0);
+MODULE_PARM_DESC(wdt_start, "SBC60xx WDT 'start' io port (default 0x443)");
+
+/*
+ * The 60xx board can use watchdog timeout values from one second
+ * to several minutes.  The default is one second, so if we reset
+ * the watchdog every ~250ms we should be safe.
+ */
+
+#define WDT_INTERVAL (HZ/4+1)
+
+/*
+ * We must not require too good response from the userspace daemon.
+ * Here we require the userspace daemon to send us a heartbeat
+ * char to /dev/watchdog every 30 seconds.
+ * If the daemon pulses us every 25 seconds, we can still afford
+ * a 5 second scheduling delay on the (high priority) daemon. That
+ * should be sufficient for a box under any load.
+ */
+
+#define WATCHDOG_TIMEOUT 30		/* 30 sec default timeout */
+static int timeout = WATCHDOG_TIMEOUT;	/* in seconds, multiplied by HZ to
+					   get seconds to wait for a ping */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,
+	"Watchdog timeout in seconds. (1<=timeout<=3600, 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) ")");
+
+static void wdt_timer_ping(struct timer_list *);
+static DEFINE_TIMER(timer, wdt_timer_ping);
+static unsigned long next_heartbeat;
+static unsigned long wdt_is_open;
+static char wdt_expect_close;
+
+/*
+ *	Whack the dog
+ */
+
+static void wdt_timer_ping(struct timer_list *unused)
+{
+	/* If we got a heartbeat pulse within the WDT_US_INTERVAL
+	 * we agree to ping the WDT
+	 */
+	if (time_before(jiffies, next_heartbeat)) {
+		/* Ping the WDT by reading from wdt_start */
+		inb_p(wdt_start);
+		/* Re-set the timer interval */
+		mod_timer(&timer, jiffies + WDT_INTERVAL);
+	} else
+		pr_warn("Heartbeat lost! Will not ping the watchdog\n");
+}
+
+/*
+ * Utility routines
+ */
+
+static void wdt_startup(void)
+{
+	next_heartbeat = jiffies + (timeout * HZ);
+
+	/* Start the timer */
+	mod_timer(&timer, jiffies + WDT_INTERVAL);
+	pr_info("Watchdog timer is now enabled\n");
+}
+
+static void wdt_turnoff(void)
+{
+	/* Stop the timer */
+	del_timer_sync(&timer);
+	inb_p(wdt_stop);
+	pr_info("Watchdog timer is now disabled...\n");
+}
+
+static void wdt_keepalive(void)
+{
+	/* user land ping */
+	next_heartbeat = jiffies + (timeout * HZ);
+}
+
+/*
+ * /dev/watchdog handling
+ */
+
+static ssize_t fop_write(struct file *file, const char __user *buf,
+						size_t count, loff_t *ppos)
+{
+	/* See if we got the magic character 'V' and reload the timer */
+	if (count) {
+		if (!nowayout) {
+			size_t ofs;
+
+			/* note: just in case someone wrote the
+			   magic character five months ago... */
+			wdt_expect_close = 0;
+
+			/* scan to see whether or not we got the
+			   magic character */
+			for (ofs = 0; ofs != count; ofs++) {
+				char c;
+				if (get_user(c, buf + ofs))
+					return -EFAULT;
+				if (c == 'V')
+					wdt_expect_close = 42;
+			}
+		}
+
+		/* Well, anyhow someone wrote to us, we should
+		   return that favour */
+		wdt_keepalive();
+	}
+	return count;
+}
+
+static int fop_open(struct inode *inode, struct file *file)
+{
+	/* Just in case we're already talking to someone... */
+	if (test_and_set_bit(0, &wdt_is_open))
+		return -EBUSY;
+
+	if (nowayout)
+		__module_get(THIS_MODULE);
+
+	/* Good, fire up the show */
+	wdt_startup();
+	return stream_open(inode, file);
+}
+
+static int fop_close(struct inode *inode, struct file *file)
+{
+	if (wdt_expect_close == 42)
+		wdt_turnoff();
+	else {
+		del_timer(&timer);
+		pr_crit("device file closed unexpectedly. Will not stop the WDT!\n");
+	}
+	clear_bit(0, &wdt_is_open);
+	wdt_expect_close = 0;
+	return 0;
+}
+
+static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	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 = "SBC60xx",
+	};
+
+	switch (cmd) {
+	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_SETOPTIONS:
+	{
+		int new_options, retval = -EINVAL;
+		if (get_user(new_options, p))
+			return -EFAULT;
+		if (new_options & WDIOS_DISABLECARD) {
+			wdt_turnoff();
+			retval = 0;
+		}
+		if (new_options & WDIOS_ENABLECARD) {
+			wdt_startup();
+			retval = 0;
+		}
+		return retval;
+	}
+	case WDIOC_KEEPALIVE:
+		wdt_keepalive();
+		return 0;
+	case WDIOC_SETTIMEOUT:
+	{
+		int new_timeout;
+		if (get_user(new_timeout, p))
+			return -EFAULT;
+		/* arbitrary upper limit */
+		if (new_timeout < 1 || new_timeout > 3600)
+			return -EINVAL;
+
+		timeout = new_timeout;
+		wdt_keepalive();
+	}
+		fallthrough;
+	case WDIOC_GETTIMEOUT:
+		return put_user(timeout, p);
+	default:
+		return -ENOTTY;
+	}
+}
+
+static const struct file_operations wdt_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= no_llseek,
+	.write		= fop_write,
+	.open		= fop_open,
+	.release	= fop_close,
+	.unlocked_ioctl	= fop_ioctl,
+	.compat_ioctl	= compat_ptr_ioctl,
+};
+
+static struct miscdevice wdt_miscdev = {
+	.minor = WATCHDOG_MINOR,
+	.name = "watchdog",
+	.fops = &wdt_fops,
+};
+
+/*
+ *	Notifier for system down
+ */
+
+static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
+	void *unused)
+{
+	if (code == SYS_DOWN || code == SYS_HALT)
+		wdt_turnoff();
+	return NOTIFY_DONE;
+}
+
+/*
+ *	The WDT needs to learn about soft shutdowns in order to
+ *	turn the timebomb registers off.
+ */
+
+static struct notifier_block wdt_notifier = {
+	.notifier_call = wdt_notify_sys,
+};
+
+static void __exit sbc60xxwdt_unload(void)
+{
+	wdt_turnoff();
+
+	/* Deregister */
+	misc_deregister(&wdt_miscdev);
+
+	unregister_reboot_notifier(&wdt_notifier);
+	if ((wdt_stop != 0x45) && (wdt_stop != wdt_start))
+		release_region(wdt_stop, 1);
+	release_region(wdt_start, 1);
+}
+
+static int __init sbc60xxwdt_init(void)
+{
+	int rc = -EBUSY;
+
+	if (timeout < 1 || timeout > 3600) { /* arbitrary upper limit */
+		timeout = WATCHDOG_TIMEOUT;
+		pr_info("timeout value must be 1 <= x <= 3600, using %d\n",
+			timeout);
+	}
+
+	if (!request_region(wdt_start, 1, "SBC 60XX WDT")) {
+		pr_err("I/O address 0x%04x already in use\n", wdt_start);
+		rc = -EIO;
+		goto err_out;
+	}
+
+	/* We cannot reserve 0x45 - the kernel already has! */
+	if (wdt_stop != 0x45 && wdt_stop != wdt_start) {
+		if (!request_region(wdt_stop, 1, "SBC 60XX WDT")) {
+			pr_err("I/O address 0x%04x already in use\n", wdt_stop);
+			rc = -EIO;
+			goto err_out_region1;
+		}
+	}
+
+	rc = register_reboot_notifier(&wdt_notifier);
+	if (rc) {
+		pr_err("cannot register reboot notifier (err=%d)\n", rc);
+		goto err_out_region2;
+	}
+
+	rc = misc_register(&wdt_miscdev);
+	if (rc) {
+		pr_err("cannot register miscdev on minor=%d (err=%d)\n",
+		       wdt_miscdev.minor, rc);
+		goto err_out_reboot;
+	}
+	pr_info("WDT driver for 60XX single board computer initialised. timeout=%d sec (nowayout=%d)\n",
+		timeout, nowayout);
+
+	return 0;
+
+err_out_reboot:
+	unregister_reboot_notifier(&wdt_notifier);
+err_out_region2:
+	if (wdt_stop != 0x45 && wdt_stop != wdt_start)
+		release_region(wdt_stop, 1);
+err_out_region1:
+	release_region(wdt_start, 1);
+err_out:
+	return rc;
+}
+
+module_init(sbc60xxwdt_init);
+module_exit(sbc60xxwdt_unload);
+
+MODULE_AUTHOR("Jakob Oestergaard <jakob@unthought.net>");
+MODULE_DESCRIPTION("60xx Single Board Computer Watchdog Timer driver");
+MODULE_LICENSE("GPL");