--- /dev/null
+/*
+ * SBC8360 Watchdog driver
+ *
+ * (c) Copyright 2005 Webcon, Inc.
+ *
+ * Based on ib700wdt.c, which is based on advantechwdt.c which is based
+ * on acquirewdt.c which is based on wdt.c.
+ *
+ * (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@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@redhat.com>
+ *
+ * 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
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/ioport.h>
+#include <linux/delay.h>
+#include <linux/notifier.h>
+#include <linux/fs.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/moduleparam.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+static unsigned long sbc8360_is_open;
+static spinlock_t sbc8360_lock;
+static char expect_close;
+
+#define PFX "sbc8360: "
+
+/*
+ *
+ * Watchdog Timer Configuration
+ *
+ * The function of the watchdog timer is to reset the system automatically
+ * and is defined at I/O port 0120H and 0121H. To enable the watchdog timer
+ * and allow the system to reset, write appropriate values from the table
+ * below to I/O port 0120H and 0121H. To disable the timer, write a zero
+ * value to I/O port 0121H for the system to stop the watchdog function.
+ *
+ * The following describes how the timer should be programmed (according to
+ * the vendor documentation)
+ *
+ * Enabling Watchdog:
+ * MOV AX,000AH (enable, phase I)
+ * MOV DX,0120H
+ * OUT DX,AX
+ * MOV AX,000BH (enable, phase II)
+ * MOV DX,0120H
+ * OUT DX,AX
+ * MOV AX,000nH (set multiplier n, from 1-4)
+ * MOV DX,0120H
+ * OUT DX,AX
+ * MOV AX,000mH (set base timer m, from 0-F)
+ * MOV DX,0121H
+ * OUT DX,AX
+ *
+ * Reset timer:
+ * MOV AX,000mH (same as set base timer, above)
+ * MOV DX,0121H
+ * OUT DX,AX
+ *
+ * Disabling Watchdog:
+ * MOV AX,0000H (a zero value)
+ * MOV DX,0120H
+ * OUT DX,AX
+ *
+ * Watchdog timeout configuration values:
+ * N
+ * M | 1 2 3 4
+ * --|----------------------------------
+ * 0 | 0.5s 5s 50s 100s
+ * 1 | 1s 10s 100s 200s
+ * 2 | 1.5s 15s 150s 300s
+ * 3 | 2s 20s 200s 400s
+ * 4 | 2.5s 25s 250s 500s
+ * 5 | 3s 30s 300s 600s
+ * 6 | 3.5s 35s 350s 700s
+ * 7 | 4s 40s 400s 800s
+ * 8 | 4.5s 45s 450s 900s
+ * 9 | 5s 50s 500s 1000s
+ * A | 5.5s 55s 550s 1100s
+ * B | 6s 60s 600s 1200s
+ * C | 6.5s 65s 650s 1300s
+ * D | 7s 70s 700s 1400s
+ * E | 7.5s 75s 750s 1500s
+ * F | 8s 80s 800s 1600s
+ *
+ * Another way to say the same things is:
+ * For N=1, Timeout = (M+1) * 0.5s
+ * For N=2, Timeout = (M+1) * 5s
+ * For N=3, Timeout = (M+1) * 50s
+ * For N=4, Timeout = (M+1) * 100s
+ *
+ */
+
+static int wd_times[64][2] = {
+ {0, 1}, /* 0 = 0.5s */
+ {1, 1}, /* 1 = 1s */
+ {2, 1}, /* 2 = 1.5s */
+ {3, 1}, /* 3 = 2s */
+ {4, 1}, /* 4 = 2.5s */
+ {5, 1}, /* 5 = 3s */
+ {6, 1}, /* 6 = 3.5s */
+ {7, 1}, /* 7 = 4s */
+ {8, 1}, /* 8 = 4.5s */
+ {9, 1}, /* 9 = 5s */
+ {0xA, 1}, /* 10 = 5.5s */
+ {0xB, 1}, /* 11 = 6s */
+ {0xC, 1}, /* 12 = 6.5s */
+ {0xD, 1}, /* 13 = 7s */
+ {0xE, 1}, /* 14 = 7.5s */
+ {0xF, 1}, /* 15 = 8s */
+ {0, 2}, /* 16 = 5s */
+ {1, 2}, /* 17 = 10s */
+ {2, 2}, /* 18 = 15s */
+ {3, 2}, /* 19 = 20s */
+ {4, 2}, /* 20 = 25s */
+ {5, 2}, /* 21 = 30s */
+ {6, 2}, /* 22 = 35s */
+ {7, 2}, /* 23 = 40s */
+ {8, 2}, /* 24 = 45s */
+ {9, 2}, /* 25 = 50s */
+ {0xA, 2}, /* 26 = 55s */
+ {0xB, 2}, /* 27 = 60s */
+ {0xC, 2}, /* 28 = 65s */
+ {0xD, 2}, /* 29 = 70s */
+ {0xE, 2}, /* 30 = 75s */
+ {0xF, 2}, /* 31 = 80s */
+ {0, 3}, /* 32 = 50s */
+ {1, 3}, /* 33 = 100s */
+ {2, 3}, /* 34 = 150s */
+ {3, 3}, /* 35 = 200s */
+ {4, 3}, /* 36 = 250s */
+ {5, 3}, /* 37 = 300s */
+ {6, 3}, /* 38 = 350s */
+ {7, 3}, /* 39 = 400s */
+ {8, 3}, /* 40 = 450s */
+ {9, 3}, /* 41 = 500s */
+ {0xA, 3}, /* 42 = 550s */
+ {0xB, 3}, /* 43 = 600s */
+ {0xC, 3}, /* 44 = 650s */
+ {0xD, 3}, /* 45 = 700s */
+ {0xE, 3}, /* 46 = 750s */
+ {0xF, 3}, /* 47 = 800s */
+ {0, 4}, /* 48 = 100s */
+ {1, 4}, /* 49 = 200s */
+ {2, 4}, /* 50 = 300s */
+ {3, 4}, /* 51 = 400s */
+ {4, 4}, /* 52 = 500s */
+ {5, 4}, /* 53 = 600s */
+ {6, 4}, /* 54 = 700s */
+ {7, 4}, /* 55 = 800s */
+ {8, 4}, /* 56 = 900s */
+ {9, 4}, /* 57 = 1000s */
+ {0xA, 4}, /* 58 = 1100s */
+ {0xB, 4}, /* 59 = 1200s */
+ {0xC, 4}, /* 60 = 1300s */
+ {0xD, 4}, /* 61 = 1400s */
+ {0xE, 4}, /* 62 = 1500s */
+ {0xF, 4} /* 63 = 1600s */
+};
+
+#define SBC8360_ENABLE 0x120
+#define SBC8360_BASETIME 0x121
+
+static int timeout = 27;
+static int wd_margin = 0xB;
+static int wd_multiplier = 2;
+
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
+
+module_param(timeout, int, 27);
+MODULE_PARM_DESC(timeout, "Index into timeout table (0-63) (default=27 (60s))");
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout,
+ "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
+
+/*
+ * Kernel methods.
+ */
+
+/* Activate and pre-configure watchdog */
+static void sbc8360_activate(void)
+{
+ /* Enable the watchdog */
+ outb(0x0A, SBC8360_ENABLE);
+ msleep_interruptible(100);
+ outb(0x0B, SBC8360_ENABLE);
+ msleep_interruptible(100);
+ /* Set timeout multiplier */
+ outb(wd_multiplier, SBC8360_ENABLE);
+ msleep_interruptible(100);
+ /* Nothing happens until first sbc8360_ping() */
+}
+
+/* Kernel pings watchdog */
+static void sbc8360_ping(void)
+{
+ /* Write the base timer register */
+ outb(wd_margin, SBC8360_BASETIME);
+}
+
+/* Userspace pings kernel driver, or requests clean close */
+static ssize_t sbc8360_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;
+ }
+ }
+ sbc8360_ping();
+ }
+ return count;
+}
+
+static int sbc8360_open(struct inode *inode, struct file *file)
+{
+ spin_lock(&sbc8360_lock);
+ if (test_and_set_bit(0, &sbc8360_is_open)) {
+ spin_unlock(&sbc8360_lock);
+ return -EBUSY;
+ }
+ if (nowayout)
+ __module_get(THIS_MODULE);
+
+ /* Activate and ping once to start the countdown */
+ spin_unlock(&sbc8360_lock);
+ sbc8360_activate();
+ sbc8360_ping();
+ return nonseekable_open(inode, file);
+}
+
+static int sbc8360_close(struct inode *inode, struct file *file)
+{
+ spin_lock(&sbc8360_lock);
+ if (expect_close == 42)
+ outb(0, SBC8360_ENABLE);
+ else
+ printk(KERN_CRIT PFX
+ "SBC8360 device closed unexpectedly. SBC8360 will not stop!\n");
+
+ clear_bit(0, &sbc8360_is_open);
+ expect_close = 0;
+ spin_unlock(&sbc8360_lock);
+ return 0;
+}
+
+/*
+ * Notifier for system down
+ */
+
+static int sbc8360_notify_sys(struct notifier_block *this, unsigned long code,
+ void *unused)
+{
+ if (code == SYS_DOWN || code == SYS_HALT) {
+ /* Disable the SBC8360 Watchdog */
+ outb(0, SBC8360_ENABLE);
+ }
+ return NOTIFY_DONE;
+}
+
+/*
+ * Kernel Interfaces
+ */
+
+static struct file_operations sbc8360_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = sbc8360_write,
+ .open = sbc8360_open,
+ .release = sbc8360_close,
+};
+
+static struct miscdevice sbc8360_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &sbc8360_fops,
+};
+
+/*
+ * The SBC8360 needs to learn about soft shutdowns in order to
+ * turn the timebomb registers off.
+ */
+
+static struct notifier_block sbc8360_notifier = {
+ .notifier_call = sbc8360_notify_sys,
+};
+
+static int __init sbc8360_init(void)
+{
+ int res;
+ unsigned long int mseconds = 60000;
+
+ spin_lock_init(&sbc8360_lock);
+ res = misc_register(&sbc8360_miscdev);
+ if (res) {
+ printk(KERN_ERR PFX "failed to register misc device\n");
+ goto out_nomisc;
+ }
+
+ if (!request_region(SBC8360_ENABLE, 1, "SBC8360")) {
+ printk(KERN_ERR PFX "ENABLE method I/O %X is not available.\n",
+ SBC8360_ENABLE);
+ res = -EIO;
+ goto out_noenablereg;
+ }
+ if (!request_region(SBC8360_BASETIME, 1, "SBC8360")) {
+ printk(KERN_ERR PFX
+ "BASETIME method I/O %X is not available.\n",
+ SBC8360_BASETIME);
+ res = -EIO;
+ goto out_nobasetimereg;
+ }
+
+ res = register_reboot_notifier(&sbc8360_notifier);
+ if (res) {
+ printk(KERN_ERR PFX "Failed to register reboot notifier.\n");
+ goto out_noreboot;
+ }
+
+ if (timeout < 0 || timeout > 63) {
+ printk(KERN_ERR PFX "Invalid timeout index (must be 0-63).\n");
+ res = -EINVAL;
+ goto out_noreboot;
+ }
+
+ wd_margin = wd_times[timeout][0];
+ wd_multiplier = wd_times[timeout][1];
+
+ if (wd_multiplier == 1)
+ mseconds = (wd_margin + 1) * 500;
+ else if (wd_multiplier == 2)
+ mseconds = (wd_margin + 1) * 5000;
+ else if (wd_multiplier == 3)
+ mseconds = (wd_margin + 1) * 50000;
+ else if (wd_multiplier == 4)
+ mseconds = (wd_margin + 1) * 100000;
+
+ /* My kingdom for the ability to print "0.5 seconds" in the kernel! */
+ printk(KERN_INFO PFX "Timeout set at %ld ms.\n", mseconds);
+
+ return 0;
+
+ out_noreboot:
+ release_region(SBC8360_ENABLE, 1);
+ release_region(SBC8360_BASETIME, 1);
+ out_noenablereg:
+ out_nobasetimereg:
+ misc_deregister(&sbc8360_miscdev);
+ out_nomisc:
+ return res;
+}
+
+static void __exit sbc8360_exit(void)
+{
+ misc_deregister(&sbc8360_miscdev);
+ unregister_reboot_notifier(&sbc8360_notifier);
+ release_region(SBC8360_ENABLE, 1);
+ release_region(SBC8360_BASETIME, 1);
+}
+
+module_init(sbc8360_init);
+module_exit(sbc8360_exit);
+
+MODULE_AUTHOR("Ian E. Morgan <imorgan@webcon.ca>");
+MODULE_DESCRIPTION("SBC8360 watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("1.0");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+
+/* end of sbc8360.c */
projects / linux-drm-fsl-dcu.git / commitdiff