Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 1 | /* |
| 2 | * drivers/char/watchdog/iop_wdt.c |
| 3 | * |
| 4 | * WDT driver for Intel I/O Processors |
| 5 | * Copyright (C) 2005, Intel Corporation. |
| 6 | * |
| 7 | * Based on ixp4xx driver, Copyright 2004 (c) MontaVista, Software, Inc. |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify it |
| 10 | * under the terms and conditions of the GNU General Public License, |
| 11 | * version 2, as published by the Free Software Foundation. |
| 12 | * |
| 13 | * This program is distributed in the hope it will be useful, but WITHOUT |
| 14 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 15 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 16 | * more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License along with |
| 19 | * this program; if not, write to the Free Software Foundation, Inc., 59 Temple |
| 20 | * Place - Suite 330, Boston, MA 02111-1307 USA. |
| 21 | * |
| 22 | * Curt E Bruns <curt.e.bruns@intel.com> |
| 23 | * Peter Milne <peter.milne@d-tacq.com> |
| 24 | * Dan Williams <dan.j.williams@intel.com> |
| 25 | */ |
| 26 | |
| 27 | #include <linux/module.h> |
| 28 | #include <linux/kernel.h> |
| 29 | #include <linux/fs.h> |
| 30 | #include <linux/init.h> |
| 31 | #include <linux/device.h> |
| 32 | #include <linux/miscdevice.h> |
| 33 | #include <linux/watchdog.h> |
| 34 | #include <linux/uaccess.h> |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 35 | #include <mach/hardware.h> |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 36 | |
| 37 | static int nowayout = WATCHDOG_NOWAYOUT; |
| 38 | static unsigned long wdt_status; |
| 39 | static unsigned long boot_status; |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 40 | static spinlock_t wdt_lock; |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 41 | |
| 42 | #define WDT_IN_USE 0 |
| 43 | #define WDT_OK_TO_CLOSE 1 |
| 44 | #define WDT_ENABLED 2 |
| 45 | |
| 46 | static unsigned long iop_watchdog_timeout(void) |
| 47 | { |
| 48 | return (0xffffffffUL / get_iop_tick_rate()); |
| 49 | } |
| 50 | |
| 51 | /** |
| 52 | * wdt_supports_disable - determine if we are accessing a iop13xx watchdog |
| 53 | * or iop3xx by whether it has a disable command |
| 54 | */ |
| 55 | static int wdt_supports_disable(void) |
| 56 | { |
| 57 | int can_disable; |
| 58 | |
| 59 | if (IOP_WDTCR_EN_ARM != IOP_WDTCR_DIS_ARM) |
| 60 | can_disable = 1; |
| 61 | else |
| 62 | can_disable = 0; |
| 63 | |
| 64 | return can_disable; |
| 65 | } |
| 66 | |
| 67 | static void wdt_enable(void) |
| 68 | { |
| 69 | /* Arm and enable the Timer to starting counting down from 0xFFFF.FFFF |
| 70 | * Takes approx. 10.7s to timeout |
| 71 | */ |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 72 | spin_lock(&wdt_lock); |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 73 | write_wdtcr(IOP_WDTCR_EN_ARM); |
| 74 | write_wdtcr(IOP_WDTCR_EN); |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 75 | spin_unlock(&wdt_lock); |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 76 | } |
| 77 | |
| 78 | /* returns 0 if the timer was successfully disabled */ |
| 79 | static int wdt_disable(void) |
| 80 | { |
| 81 | /* Stop Counting */ |
| 82 | if (wdt_supports_disable()) { |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 83 | spin_lock(&wdt_lock); |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 84 | write_wdtcr(IOP_WDTCR_DIS_ARM); |
| 85 | write_wdtcr(IOP_WDTCR_DIS); |
| 86 | clear_bit(WDT_ENABLED, &wdt_status); |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 87 | spin_unlock(&wdt_lock); |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 88 | printk(KERN_INFO "WATCHDOG: Disabled\n"); |
| 89 | return 0; |
| 90 | } else |
| 91 | return 1; |
| 92 | } |
| 93 | |
| 94 | static int iop_wdt_open(struct inode *inode, struct file *file) |
| 95 | { |
| 96 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) |
| 97 | return -EBUSY; |
| 98 | |
| 99 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 100 | wdt_enable(); |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 101 | set_bit(WDT_ENABLED, &wdt_status); |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 102 | return nonseekable_open(inode, file); |
| 103 | } |
| 104 | |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 105 | static ssize_t iop_wdt_write(struct file *file, const char *data, size_t len, |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 106 | loff_t *ppos) |
| 107 | { |
| 108 | if (len) { |
| 109 | if (!nowayout) { |
| 110 | size_t i; |
| 111 | |
| 112 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 113 | |
| 114 | for (i = 0; i != len; i++) { |
| 115 | char c; |
| 116 | |
| 117 | if (get_user(c, data + i)) |
| 118 | return -EFAULT; |
| 119 | if (c == 'V') |
| 120 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 121 | } |
| 122 | } |
| 123 | wdt_enable(); |
| 124 | } |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 125 | return len; |
| 126 | } |
| 127 | |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 128 | static const struct watchdog_info ident = { |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 129 | .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, |
| 130 | .identity = "iop watchdog", |
| 131 | }; |
| 132 | |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 133 | static long iop_wdt_ioctl(struct file *file, |
| 134 | unsigned int cmd, unsigned long arg) |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 135 | { |
| 136 | int options; |
| 137 | int ret = -ENOTTY; |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 138 | int __user *argp = (int __user *)arg; |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 139 | |
| 140 | switch (cmd) { |
| 141 | case WDIOC_GETSUPPORT: |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 142 | if (copy_to_user(argp, &ident, sizeof ident)) |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 143 | ret = -EFAULT; |
| 144 | else |
| 145 | ret = 0; |
| 146 | break; |
| 147 | |
| 148 | case WDIOC_GETSTATUS: |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 149 | ret = put_user(0, argp); |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 150 | break; |
| 151 | |
| 152 | case WDIOC_GETBOOTSTATUS: |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 153 | ret = put_user(boot_status, argp); |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 154 | break; |
| 155 | |
| 156 | case WDIOC_SETOPTIONS: |
| 157 | if (get_user(options, (int *)arg)) |
| 158 | return -EFAULT; |
| 159 | |
| 160 | if (options & WDIOS_DISABLECARD) { |
| 161 | if (!nowayout) { |
| 162 | if (wdt_disable() == 0) { |
| 163 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 164 | ret = 0; |
| 165 | } else |
| 166 | ret = -ENXIO; |
| 167 | } else |
| 168 | ret = 0; |
| 169 | } |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 170 | if (options & WDIOS_ENABLECARD) { |
| 171 | wdt_enable(); |
| 172 | ret = 0; |
| 173 | } |
| 174 | break; |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 175 | |
Wim Van Sebroeck | 0c06090 | 2008-07-18 11:41:17 +0000 | [diff] [blame] | 176 | case WDIOC_KEEPALIVE: |
| 177 | wdt_enable(); |
| 178 | ret = 0; |
| 179 | break; |
| 180 | |
| 181 | case WDIOC_GETTIMEOUT: |
| 182 | ret = put_user(iop_watchdog_timeout(), argp); |
| 183 | break; |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 184 | } |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 185 | return ret; |
| 186 | } |
| 187 | |
| 188 | static int iop_wdt_release(struct inode *inode, struct file *file) |
| 189 | { |
| 190 | int state = 1; |
| 191 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) |
| 192 | if (test_bit(WDT_ENABLED, &wdt_status)) |
| 193 | state = wdt_disable(); |
| 194 | |
| 195 | /* if the timer is not disbaled reload and notify that we are still |
| 196 | * going down |
| 197 | */ |
| 198 | if (state != 0) { |
| 199 | wdt_enable(); |
| 200 | printk(KERN_CRIT "WATCHDOG: Device closed unexpectedly - " |
| 201 | "reset in %lu seconds\n", iop_watchdog_timeout()); |
| 202 | } |
| 203 | |
| 204 | clear_bit(WDT_IN_USE, &wdt_status); |
| 205 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 206 | |
| 207 | return 0; |
| 208 | } |
| 209 | |
| 210 | static const struct file_operations iop_wdt_fops = { |
| 211 | .owner = THIS_MODULE, |
| 212 | .llseek = no_llseek, |
| 213 | .write = iop_wdt_write, |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 214 | .unlocked_ioctl = iop_wdt_ioctl, |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 215 | .open = iop_wdt_open, |
| 216 | .release = iop_wdt_release, |
| 217 | }; |
| 218 | |
| 219 | static struct miscdevice iop_wdt_miscdev = { |
| 220 | .minor = WATCHDOG_MINOR, |
| 221 | .name = "watchdog", |
| 222 | .fops = &iop_wdt_fops, |
| 223 | }; |
| 224 | |
| 225 | static int __init iop_wdt_init(void) |
| 226 | { |
| 227 | int ret; |
| 228 | |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 229 | spin_lock_init(&wdt_lock); |
| 230 | |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 231 | |
| 232 | /* check if the reset was caused by the watchdog timer */ |
| 233 | boot_status = (read_rcsr() & IOP_RCSR_WDT) ? WDIOF_CARDRESET : 0; |
| 234 | |
| 235 | /* Configure Watchdog Timeout to cause an Internal Bus (IB) Reset |
| 236 | * NOTE: An IB Reset will Reset both cores in the IOP342 |
| 237 | */ |
| 238 | write_wdtsr(IOP13XX_WDTCR_IB_RESET); |
| 239 | |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 240 | /* Register after we have the device set up so we cannot race |
| 241 | with an open */ |
| 242 | ret = misc_register(&iop_wdt_miscdev); |
| 243 | if (ret == 0) |
Wim Van Sebroeck | 7944d3a | 2008-08-06 20:19:41 +0000 | [diff] [blame] | 244 | printk(KERN_INFO "iop watchdog timer: timeout %lu sec\n", |
Alan Cox | 02e3814e | 2008-05-19 14:06:14 +0100 | [diff] [blame] | 245 | iop_watchdog_timeout()); |
| 246 | |
Dan Williams | 70c14ff | 2007-07-20 02:07:26 +0100 | [diff] [blame] | 247 | return ret; |
| 248 | } |
| 249 | |
| 250 | static void __exit iop_wdt_exit(void) |
| 251 | { |
| 252 | misc_deregister(&iop_wdt_miscdev); |
| 253 | } |
| 254 | |
| 255 | module_init(iop_wdt_init); |
| 256 | module_exit(iop_wdt_exit); |
| 257 | |
| 258 | module_param(nowayout, int, 0); |
| 259 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); |
| 260 | |
| 261 | MODULE_AUTHOR("Curt E Bruns <curt.e.bruns@intel.com>"); |
| 262 | MODULE_DESCRIPTION("iop watchdog timer driver"); |
| 263 | MODULE_LICENSE("GPL"); |
| 264 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |