Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 1 | /* |
| 2 | * SBC EPX C3 0.1 A Hardware Watchdog Device for the Winsystems EPX-C3 |
| 3 | * single board computer |
| 4 | * |
| 5 | * (c) Copyright 2006 Calin A. Culianu <calin@ajvar.org>, All Rights |
| 6 | * Reserved. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License |
| 10 | * as published by the Free Software Foundation; either version |
| 11 | * 2 of the License, or (at your option) any later version. |
| 12 | * |
Alan Cox | 29fa058 | 2008-10-27 15:17:56 +0000 | [diff] [blame] | 13 | * based on softdog.c by Alan Cox <alan@lxorguk.ukuu.org.uk> |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 14 | */ |
| 15 | |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 16 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 17 | |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 18 | #include <linux/module.h> |
| 19 | #include <linux/moduleparam.h> |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 20 | #include <linux/types.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/fs.h> |
| 23 | #include <linux/mm.h> |
| 24 | #include <linux/miscdevice.h> |
| 25 | #include <linux/watchdog.h> |
| 26 | #include <linux/notifier.h> |
| 27 | #include <linux/reboot.h> |
| 28 | #include <linux/init.h> |
Alan Cox | de6c642 | 2006-02-03 03:03:58 -0800 | [diff] [blame] | 29 | #include <linux/ioport.h> |
Alan Cox | f4f6f65 | 2008-05-19 14:08:27 +0100 | [diff] [blame] | 30 | #include <linux/uaccess.h> |
| 31 | #include <linux/io.h> |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 32 | |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 33 | static int epx_c3_alive; |
| 34 | |
| 35 | #define WATCHDOG_TIMEOUT 1 /* 1 sec default timeout */ |
| 36 | |
Wim Van Sebroeck | 86a1e18 | 2012-03-05 16:51:11 +0100 | [diff] [blame] | 37 | static bool nowayout = WATCHDOG_NOWAYOUT; |
| 38 | module_param(nowayout, bool, 0); |
Wim Van Sebroeck | 143a2e5 | 2009-03-18 08:35:09 +0000 | [diff] [blame] | 39 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" |
| 40 | __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 41 | |
| 42 | #define EPXC3_WATCHDOG_CTL_REG 0x1ee /* write 1 to enable, 0 to disable */ |
| 43 | #define EPXC3_WATCHDOG_PET_REG 0x1ef /* write anything to pet once enabled */ |
| 44 | |
| 45 | static void epx_c3_start(void) |
| 46 | { |
| 47 | outb(1, EPXC3_WATCHDOG_CTL_REG); |
| 48 | } |
| 49 | |
| 50 | static void epx_c3_stop(void) |
| 51 | { |
| 52 | |
| 53 | outb(0, EPXC3_WATCHDOG_CTL_REG); |
| 54 | |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 55 | pr_info("Stopped watchdog timer\n"); |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 56 | } |
| 57 | |
| 58 | static void epx_c3_pet(void) |
| 59 | { |
| 60 | outb(1, EPXC3_WATCHDOG_PET_REG); |
| 61 | } |
| 62 | |
| 63 | /* |
| 64 | * Allow only one person to hold it open |
| 65 | */ |
| 66 | static int epx_c3_open(struct inode *inode, struct file *file) |
| 67 | { |
| 68 | if (epx_c3_alive) |
| 69 | return -EBUSY; |
| 70 | |
| 71 | if (nowayout) |
| 72 | __module_get(THIS_MODULE); |
| 73 | |
| 74 | /* Activate timer */ |
| 75 | epx_c3_start(); |
| 76 | epx_c3_pet(); |
| 77 | |
| 78 | epx_c3_alive = 1; |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 79 | pr_info("Started watchdog timer\n"); |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 80 | |
| 81 | return nonseekable_open(inode, file); |
| 82 | } |
| 83 | |
| 84 | static int epx_c3_release(struct inode *inode, struct file *file) |
| 85 | { |
| 86 | /* Shut off the timer. |
| 87 | * Lock it in if it's a module and we defined ...NOWAYOUT */ |
| 88 | if (!nowayout) |
| 89 | epx_c3_stop(); /* Turn the WDT off */ |
| 90 | |
| 91 | epx_c3_alive = 0; |
| 92 | |
| 93 | return 0; |
| 94 | } |
| 95 | |
Al Viro | 73a09e6 | 2006-02-01 06:04:15 -0500 | [diff] [blame] | 96 | static ssize_t epx_c3_write(struct file *file, const char __user *data, |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 97 | size_t len, loff_t *ppos) |
| 98 | { |
| 99 | /* Refresh the timer. */ |
| 100 | if (len) |
| 101 | epx_c3_pet(); |
| 102 | return len; |
| 103 | } |
| 104 | |
Alan Cox | f4f6f65 | 2008-05-19 14:08:27 +0100 | [diff] [blame] | 105 | static long epx_c3_ioctl(struct file *file, unsigned int cmd, |
| 106 | unsigned long arg) |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 107 | { |
| 108 | int options, retval = -EINVAL; |
Al Viro | 73a09e6 | 2006-02-01 06:04:15 -0500 | [diff] [blame] | 109 | int __user *argp = (void __user *)arg; |
Alan Cox | f4f6f65 | 2008-05-19 14:08:27 +0100 | [diff] [blame] | 110 | static const struct watchdog_info ident = { |
Wim Van Sebroeck | e73a780 | 2009-05-11 18:33:00 +0000 | [diff] [blame] | 111 | .options = WDIOF_KEEPALIVEPING, |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 112 | .firmware_version = 0, |
| 113 | .identity = "Winsystems EPX-C3 H/W Watchdog", |
| 114 | }; |
| 115 | |
| 116 | switch (cmd) { |
| 117 | case WDIOC_GETSUPPORT: |
Al Viro | 73a09e6 | 2006-02-01 06:04:15 -0500 | [diff] [blame] | 118 | if (copy_to_user(argp, &ident, sizeof(ident))) |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 119 | return -EFAULT; |
| 120 | return 0; |
| 121 | case WDIOC_GETSTATUS: |
| 122 | case WDIOC_GETBOOTSTATUS: |
Al Viro | 73a09e6 | 2006-02-01 06:04:15 -0500 | [diff] [blame] | 123 | return put_user(0, argp); |
Al Viro | 73a09e6 | 2006-02-01 06:04:15 -0500 | [diff] [blame] | 124 | case WDIOC_SETOPTIONS: |
| 125 | if (get_user(options, argp)) |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 126 | return -EFAULT; |
| 127 | |
| 128 | if (options & WDIOS_DISABLECARD) { |
| 129 | epx_c3_stop(); |
| 130 | retval = 0; |
| 131 | } |
| 132 | |
| 133 | if (options & WDIOS_ENABLECARD) { |
| 134 | epx_c3_start(); |
| 135 | retval = 0; |
| 136 | } |
| 137 | |
| 138 | return retval; |
Wim Van Sebroeck | 0c06090 | 2008-07-18 11:41:17 +0000 | [diff] [blame] | 139 | case WDIOC_KEEPALIVE: |
| 140 | epx_c3_pet(); |
| 141 | return 0; |
| 142 | case WDIOC_GETTIMEOUT: |
| 143 | return put_user(WATCHDOG_TIMEOUT, argp); |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 144 | default: |
Samuel Tardieu | 795b89d | 2006-09-09 17:34:31 +0200 | [diff] [blame] | 145 | return -ENOTTY; |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 146 | } |
| 147 | } |
| 148 | |
| 149 | static int epx_c3_notify_sys(struct notifier_block *this, unsigned long code, |
| 150 | void *unused) |
| 151 | { |
| 152 | if (code == SYS_DOWN || code == SYS_HALT) |
| 153 | epx_c3_stop(); /* Turn the WDT off */ |
| 154 | |
| 155 | return NOTIFY_DONE; |
| 156 | } |
| 157 | |
Arjan van de Ven | 62322d2 | 2006-07-03 00:24:21 -0700 | [diff] [blame] | 158 | static const struct file_operations epx_c3_fops = { |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 159 | .owner = THIS_MODULE, |
| 160 | .llseek = no_llseek, |
| 161 | .write = epx_c3_write, |
Alan Cox | f4f6f65 | 2008-05-19 14:08:27 +0100 | [diff] [blame] | 162 | .unlocked_ioctl = epx_c3_ioctl, |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 163 | .open = epx_c3_open, |
| 164 | .release = epx_c3_release, |
| 165 | }; |
| 166 | |
| 167 | static struct miscdevice epx_c3_miscdev = { |
| 168 | .minor = WATCHDOG_MINOR, |
| 169 | .name = "watchdog", |
| 170 | .fops = &epx_c3_fops, |
| 171 | }; |
| 172 | |
| 173 | static struct notifier_block epx_c3_notifier = { |
| 174 | .notifier_call = epx_c3_notify_sys, |
| 175 | }; |
| 176 | |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 177 | static int __init watchdog_init(void) |
| 178 | { |
| 179 | int ret; |
| 180 | |
Alan Cox | de6c642 | 2006-02-03 03:03:58 -0800 | [diff] [blame] | 181 | if (!request_region(EPXC3_WATCHDOG_CTL_REG, 2, "epxc3_watchdog")) |
| 182 | return -EBUSY; |
| 183 | |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 184 | ret = register_reboot_notifier(&epx_c3_notifier); |
| 185 | if (ret) { |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 186 | pr_err("cannot register reboot notifier (err=%d)\n", ret); |
Alan Cox | de6c642 | 2006-02-03 03:03:58 -0800 | [diff] [blame] | 187 | goto out; |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 188 | } |
| 189 | |
| 190 | ret = misc_register(&epx_c3_miscdev); |
| 191 | if (ret) { |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 192 | pr_err("cannot register miscdev on minor=%d (err=%d)\n", |
| 193 | WATCHDOG_MINOR, ret); |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 194 | unregister_reboot_notifier(&epx_c3_notifier); |
Alan Cox | de6c642 | 2006-02-03 03:03:58 -0800 | [diff] [blame] | 195 | goto out; |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 196 | } |
| 197 | |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 198 | pr_info("Hardware Watchdog Timer for Winsystems EPX-C3 SBC: 0.1\n"); |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 199 | |
| 200 | return 0; |
Alan Cox | de6c642 | 2006-02-03 03:03:58 -0800 | [diff] [blame] | 201 | |
| 202 | out: |
| 203 | release_region(EPXC3_WATCHDOG_CTL_REG, 2); |
| 204 | return ret; |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 205 | } |
| 206 | |
| 207 | static void __exit watchdog_exit(void) |
| 208 | { |
| 209 | misc_deregister(&epx_c3_miscdev); |
| 210 | unregister_reboot_notifier(&epx_c3_notifier); |
Alan Cox | de6c642 | 2006-02-03 03:03:58 -0800 | [diff] [blame] | 211 | release_region(EPXC3_WATCHDOG_CTL_REG, 2); |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 212 | } |
| 213 | |
| 214 | module_init(watchdog_init); |
| 215 | module_exit(watchdog_exit); |
| 216 | |
| 217 | MODULE_AUTHOR("Calin A. Culianu <calin@ajvar.org>"); |
Wim Van Sebroeck | a77dba7 | 2009-04-14 20:20:07 +0000 | [diff] [blame] | 218 | MODULE_DESCRIPTION("Hardware Watchdog Device for Winsystems EPX-C3 SBC. " |
| 219 | "Note that there is no way to probe for this device -- " |
Justin P. Mattock | ae0e47f | 2011-03-01 15:06:02 +0100 | [diff] [blame] | 220 | "so only use it if you are *sure* you are running on this specific " |
Wim Van Sebroeck | a77dba7 | 2009-04-14 20:20:07 +0000 | [diff] [blame] | 221 | "SBC system from Winsystems! It writes to IO ports 0x1ee and 0x1ef!"); |
Calin A. Culianu | eed6565 | 2006-01-14 13:20:46 -0800 | [diff] [blame] | 222 | MODULE_LICENSE("GPL"); |
| 223 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |