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Diffstat (limited to 'drivers/watchdog/ib700wdt.c')
-rw-r--r--drivers/watchdog/ib700wdt.c379
1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/watchdog/ib700wdt.c b/drivers/watchdog/ib700wdt.c
new file mode 100644
index 000000000..a0ddedc36
--- /dev/null
+++ b/drivers/watchdog/ib700wdt.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IB700 Single Board Computer WDT driver
+ *
+ * (c) Copyright 2001 Charles Howes <chowes@vsol.net>
+ *
+ * Based on advantechwdt.c which is based on acquirewdt.c which
+ * is based on wdt.c.
+ *
+ * (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.
+ *
+ * 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
+ * Added timeout module option to override default
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/ioport.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+
+
+static struct platform_device *ibwdt_platform_device;
+static unsigned long ibwdt_is_open;
+static DEFINE_SPINLOCK(ibwdt_lock);
+static char expect_close;
+
+/* Module information */
+#define DRV_NAME "ib700wdt"
+
+/*
+ *
+ * Watchdog Timer Configuration
+ *
+ * The function of the watchdog timer is to reset the system
+ * automatically and is defined at I/O port 0443H. To enable the
+ * watchdog timer and allow the system to reset, write I/O port 0443H.
+ * To disable the timer, write I/O port 0441H for the system to stop the
+ * watchdog function. The timer has a tolerance of 20% for its
+ * intervals.
+ *
+ * The following describes how the timer should be programmed.
+ *
+ * Enabling Watchdog:
+ * MOV AX,000FH (Choose the values from 0 to F)
+ * MOV DX,0443H
+ * OUT DX,AX
+ *
+ * Disabling Watchdog:
+ * MOV AX,000FH (Any value is fine.)
+ * MOV DX,0441H
+ * OUT DX,AX
+ *
+ * Watchdog timer control table:
+ * Level Value Time/sec | Level Value Time/sec
+ * 1 F 0 | 9 7 16
+ * 2 E 2 | 10 6 18
+ * 3 D 4 | 11 5 20
+ * 4 C 6 | 12 4 22
+ * 5 B 8 | 13 3 24
+ * 6 A 10 | 14 2 26
+ * 7 9 12 | 15 1 28
+ * 8 8 14 | 16 0 30
+ *
+ */
+
+#define WDT_STOP 0x441
+#define WDT_START 0x443
+
+/* Default timeout */
+#define WATCHDOG_TIMEOUT 30 /* 30 seconds +/- 20% */
+static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
+module_param(timeout, int, 0);
+MODULE_PARM_DESC(timeout,
+ "Watchdog timeout in seconds. 0<= timeout <=30, 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 ibwdt_ping(void)
+{
+ int wd_margin = 15 - ((timeout + 1) / 2);
+
+ spin_lock(&ibwdt_lock);
+
+ /* Write a watchdog value */
+ outb_p(wd_margin, WDT_START);
+
+ spin_unlock(&ibwdt_lock);
+}
+
+static void ibwdt_disable(void)
+{
+ spin_lock(&ibwdt_lock);
+ outb_p(0, WDT_STOP);
+ spin_unlock(&ibwdt_lock);
+}
+
+static int ibwdt_set_heartbeat(int t)
+{
+ if (t < 0 || t > 30)
+ return -EINVAL;
+
+ timeout = t;
+ return 0;
+}
+
+/*
+ * /dev/watchdog handling
+ */
+
+static ssize_t ibwdt_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ if (count) {
+ if (!nowayout) {
+ size_t i;
+
+ /* In case it was set long ago */
+ expect_close = 0;
+
+ for (i = 0; i != count; i++) {
+ char c;
+ if (get_user(c, buf + i))
+ return -EFAULT;
+ if (c == 'V')
+ expect_close = 42;
+ }
+ }
+ ibwdt_ping();
+ }
+ return count;
+}
+
+static long ibwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ int new_margin;
+ 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 = "IB700 WDT",
+ };
+
+ 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) {
+ ibwdt_disable();
+ retval = 0;
+ }
+ if (options & WDIOS_ENABLECARD) {
+ ibwdt_ping();
+ retval = 0;
+ }
+ return retval;
+ }
+ case WDIOC_KEEPALIVE:
+ ibwdt_ping();
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_margin, p))
+ return -EFAULT;
+ if (ibwdt_set_heartbeat(new_margin))
+ return -EINVAL;
+ ibwdt_ping();
+ fallthrough;
+
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, p);
+
+ default:
+ return -ENOTTY;
+ }
+ return 0;
+}
+
+static int ibwdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &ibwdt_is_open))
+ return -EBUSY;
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ /* Activate */
+ ibwdt_ping();
+ return stream_open(inode, file);
+}
+
+static int ibwdt_close(struct inode *inode, struct file *file)
+{
+ if (expect_close == 42) {
+ ibwdt_disable();
+ } else {
+ pr_crit("WDT device closed unexpectedly. WDT will not stop!\n");
+ ibwdt_ping();
+ }
+ clear_bit(0, &ibwdt_is_open);
+ expect_close = 0;
+ return 0;
+}
+
+/*
+ * Kernel Interfaces
+ */
+
+static const struct file_operations ibwdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = ibwdt_write,
+ .unlocked_ioctl = ibwdt_ioctl,
+ .compat_ioctl = compat_ptr_ioctl,
+ .open = ibwdt_open,
+ .release = ibwdt_close,
+};
+
+static struct miscdevice ibwdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &ibwdt_fops,
+};
+
+/*
+ * Init & exit routines
+ */
+
+static int __init ibwdt_probe(struct platform_device *dev)
+{
+ int res;
+
+#if WDT_START != WDT_STOP
+ if (!request_region(WDT_STOP, 1, "IB700 WDT")) {
+ pr_err("STOP method I/O %X is not available\n", WDT_STOP);
+ res = -EIO;
+ goto out_nostopreg;
+ }
+#endif
+
+ if (!request_region(WDT_START, 1, "IB700 WDT")) {
+ pr_err("START method I/O %X is not available\n", WDT_START);
+ res = -EIO;
+ goto out_nostartreg;
+ }
+
+ /* Check that the heartbeat value is within it's range ;
+ * if not reset to the default */
+ if (ibwdt_set_heartbeat(timeout)) {
+ ibwdt_set_heartbeat(WATCHDOG_TIMEOUT);
+ pr_info("timeout value must be 0<=x<=30, using %d\n", timeout);
+ }
+
+ res = misc_register(&ibwdt_miscdev);
+ if (res) {
+ pr_err("failed to register misc device\n");
+ goto out_nomisc;
+ }
+ return 0;
+
+out_nomisc:
+ release_region(WDT_START, 1);
+out_nostartreg:
+#if WDT_START != WDT_STOP
+ release_region(WDT_STOP, 1);
+#endif
+out_nostopreg:
+ return res;
+}
+
+static int ibwdt_remove(struct platform_device *dev)
+{
+ misc_deregister(&ibwdt_miscdev);
+ release_region(WDT_START, 1);
+#if WDT_START != WDT_STOP
+ release_region(WDT_STOP, 1);
+#endif
+ return 0;
+}
+
+static void ibwdt_shutdown(struct platform_device *dev)
+{
+ /* Turn the WDT off if we have a soft shutdown */
+ ibwdt_disable();
+}
+
+static struct platform_driver ibwdt_driver = {
+ .remove = ibwdt_remove,
+ .shutdown = ibwdt_shutdown,
+ .driver = {
+ .name = DRV_NAME,
+ },
+};
+
+static int __init ibwdt_init(void)
+{
+ int err;
+
+ pr_info("WDT driver for IB700 single board computer initialising\n");
+
+ ibwdt_platform_device = platform_device_register_simple(DRV_NAME,
+ -1, NULL, 0);
+ if (IS_ERR(ibwdt_platform_device))
+ return PTR_ERR(ibwdt_platform_device);
+
+ err = platform_driver_probe(&ibwdt_driver, ibwdt_probe);
+ if (err)
+ goto unreg_platform_device;
+
+ return 0;
+
+unreg_platform_device:
+ platform_device_unregister(ibwdt_platform_device);
+ return err;
+}
+
+static void __exit ibwdt_exit(void)
+{
+ platform_device_unregister(ibwdt_platform_device);
+ platform_driver_unregister(&ibwdt_driver);
+ pr_info("Watchdog Module Unloaded\n");
+}
+
+module_init(ibwdt_init);
+module_exit(ibwdt_exit);
+
+MODULE_AUTHOR("Charles Howes <chowes@vsol.net>");
+MODULE_DESCRIPTION("IB700 SBC watchdog driver");
+MODULE_LICENSE("GPL");
+
+/* end of ib700wdt.c */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-09 14:37:51 +0000