Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Uwe Zeisberger | f30c226 | 2006-10-03 23:01:26 +0200 | [diff] [blame] | 2 | * drivers/char/watchdog/ixp4xx_wdt.c |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * |
| 4 | * Watchdog driver for Intel IXP4xx network processors |
| 5 | * |
| 6 | * Author: Deepak Saxena <dsaxena@plexity.net> |
| 7 | * |
| 8 | * Copyright 2004 (c) MontaVista, Software, Inc. |
| 9 | * Based on sa1100 driver, Copyright (C) 2000 Oleg Drokin <green@crimea.edu> |
| 10 | * |
| 11 | * This file is licensed under the terms of the GNU General Public |
| 12 | * License version 2. This program is licensed "as is" without any |
| 13 | * warranty of any kind, whether express or implied. |
| 14 | */ |
| 15 | |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 16 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 17 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/module.h> |
| 19 | #include <linux/moduleparam.h> |
| 20 | #include <linux/types.h> |
| 21 | #include <linux/kernel.h> |
| 22 | #include <linux/fs.h> |
| 23 | #include <linux/miscdevice.h> |
| 24 | #include <linux/watchdog.h> |
| 25 | #include <linux/init.h> |
| 26 | #include <linux/bitops.h> |
Wim Van Sebroeck | 089ab07 | 2008-07-15 11:46:11 +0000 | [diff] [blame] | 27 | #include <linux/uaccess.h> |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 28 | #include <mach/hardware.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | |
Wim Van Sebroeck | 86a1e18 | 2012-03-05 16:51:11 +0100 | [diff] [blame] | 30 | static bool nowayout = WATCHDOG_NOWAYOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | static int heartbeat = 60; /* (secs) Default is 1 minute */ |
| 32 | static unsigned long wdt_status; |
| 33 | static unsigned long boot_status; |
Adrian Bunk | 9229376 | 2008-08-10 14:03:41 +0300 | [diff] [blame] | 34 | static DEFINE_SPINLOCK(wdt_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | |
| 36 | #define WDT_TICK_RATE (IXP4XX_PERIPHERAL_BUS_CLOCK * 1000000UL) |
| 37 | |
| 38 | #define WDT_IN_USE 0 |
| 39 | #define WDT_OK_TO_CLOSE 1 |
| 40 | |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 41 | static void wdt_enable(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | { |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 43 | spin_lock(&wdt_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | *IXP4XX_OSWK = IXP4XX_WDT_KEY; |
| 45 | *IXP4XX_OSWE = 0; |
| 46 | *IXP4XX_OSWT = WDT_TICK_RATE * heartbeat; |
| 47 | *IXP4XX_OSWE = IXP4XX_WDT_COUNT_ENABLE | IXP4XX_WDT_RESET_ENABLE; |
| 48 | *IXP4XX_OSWK = 0; |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 49 | spin_unlock(&wdt_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | } |
| 51 | |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 52 | static void wdt_disable(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | { |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 54 | spin_lock(&wdt_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | *IXP4XX_OSWK = IXP4XX_WDT_KEY; |
| 56 | *IXP4XX_OSWE = 0; |
| 57 | *IXP4XX_OSWK = 0; |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 58 | spin_unlock(&wdt_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | } |
| 60 | |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 61 | static int ixp4xx_wdt_open(struct inode *inode, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | { |
| 63 | if (test_and_set_bit(WDT_IN_USE, &wdt_status)) |
| 64 | return -EBUSY; |
| 65 | |
| 66 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | wdt_enable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | return nonseekable_open(inode, file); |
| 69 | } |
| 70 | |
| 71 | static ssize_t |
| 72 | ixp4xx_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos) |
| 73 | { |
| 74 | if (len) { |
| 75 | if (!nowayout) { |
| 76 | size_t i; |
| 77 | |
| 78 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 79 | |
| 80 | for (i = 0; i != len; i++) { |
| 81 | char c; |
| 82 | |
| 83 | if (get_user(c, data + i)) |
| 84 | return -EFAULT; |
| 85 | if (c == 'V') |
| 86 | set_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 87 | } |
| 88 | } |
| 89 | wdt_enable(); |
| 90 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | return len; |
| 92 | } |
| 93 | |
Wim Van Sebroeck | 42747d7 | 2009-12-26 18:55:22 +0000 | [diff] [blame] | 94 | static const struct watchdog_info ident = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | |
| 96 | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, |
| 97 | .identity = "IXP4xx Watchdog", |
| 98 | }; |
| 99 | |
| 100 | |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 101 | static long ixp4xx_wdt_ioctl(struct file *file, unsigned int cmd, |
| 102 | unsigned long arg) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | { |
Samuel Tardieu | 795b89d | 2006-09-09 17:34:31 +0200 | [diff] [blame] | 104 | int ret = -ENOTTY; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | int time; |
| 106 | |
| 107 | switch (cmd) { |
| 108 | case WDIOC_GETSUPPORT: |
| 109 | ret = copy_to_user((struct watchdog_info *)arg, &ident, |
| 110 | sizeof(ident)) ? -EFAULT : 0; |
| 111 | break; |
| 112 | |
| 113 | case WDIOC_GETSTATUS: |
| 114 | ret = put_user(0, (int *)arg); |
| 115 | break; |
| 116 | |
| 117 | case WDIOC_GETBOOTSTATUS: |
| 118 | ret = put_user(boot_status, (int *)arg); |
| 119 | break; |
| 120 | |
Wim Van Sebroeck | 0c06090 | 2008-07-18 11:41:17 +0000 | [diff] [blame] | 121 | case WDIOC_KEEPALIVE: |
| 122 | wdt_enable(); |
| 123 | ret = 0; |
| 124 | break; |
| 125 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | case WDIOC_SETTIMEOUT: |
| 127 | ret = get_user(time, (int *)arg); |
| 128 | if (ret) |
| 129 | break; |
| 130 | |
| 131 | if (time <= 0 || time > 60) { |
| 132 | ret = -EINVAL; |
| 133 | break; |
| 134 | } |
| 135 | |
| 136 | heartbeat = time; |
| 137 | wdt_enable(); |
| 138 | /* Fall through */ |
| 139 | |
| 140 | case WDIOC_GETTIMEOUT: |
| 141 | ret = put_user(heartbeat, (int *)arg); |
| 142 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | } |
| 144 | return ret; |
| 145 | } |
| 146 | |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 147 | static int ixp4xx_wdt_release(struct inode *inode, struct file *file) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | { |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 149 | if (test_bit(WDT_OK_TO_CLOSE, &wdt_status)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | wdt_disable(); |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 151 | else |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 152 | pr_crit("Device closed unexpectedly - timer will not stop\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | clear_bit(WDT_IN_USE, &wdt_status); |
| 154 | clear_bit(WDT_OK_TO_CLOSE, &wdt_status); |
| 155 | |
| 156 | return 0; |
| 157 | } |
| 158 | |
| 159 | |
Wim Van Sebroeck | 7944d3a | 2008-08-06 20:19:41 +0000 | [diff] [blame] | 160 | static const struct file_operations ixp4xx_wdt_fops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | .owner = THIS_MODULE, |
| 162 | .llseek = no_llseek, |
| 163 | .write = ixp4xx_wdt_write, |
Alan Cox | 20d35f3 | 2008-05-19 14:06:48 +0100 | [diff] [blame] | 164 | .unlocked_ioctl = ixp4xx_wdt_ioctl, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | .open = ixp4xx_wdt_open, |
| 166 | .release = ixp4xx_wdt_release, |
| 167 | }; |
| 168 | |
Wim Van Sebroeck | 7944d3a | 2008-08-06 20:19:41 +0000 | [diff] [blame] | 169 | static struct miscdevice ixp4xx_wdt_miscdev = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | .minor = WATCHDOG_MINOR, |
Olaf Hering | 2dab3ca | 2005-08-17 08:58:34 +0200 | [diff] [blame] | 171 | .name = "watchdog", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | .fops = &ixp4xx_wdt_fops, |
| 173 | }; |
| 174 | |
| 175 | static int __init ixp4xx_wdt_init(void) |
| 176 | { |
| 177 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | |
Russell King | 0ba8b9b | 2008-08-10 18:08:10 +0100 | [diff] [blame] | 179 | if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) { |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 180 | pr_err("Rev. A0 IXP42x CPU detected - watchdog disabled\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | |
| 182 | return -ENODEV; |
| 183 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | boot_status = (*IXP4XX_OSST & IXP4XX_OSST_TIMER_WARM_RESET) ? |
| 185 | WDIOF_CARDRESET : 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | ret = misc_register(&ixp4xx_wdt_miscdev); |
| 187 | if (ret == 0) |
Joe Perches | 27c766a | 2012-02-15 15:06:19 -0800 | [diff] [blame] | 188 | pr_info("timer heartbeat %d sec\n", heartbeat); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | return ret; |
| 190 | } |
| 191 | |
| 192 | static void __exit ixp4xx_wdt_exit(void) |
| 193 | { |
| 194 | misc_deregister(&ixp4xx_wdt_miscdev); |
| 195 | } |
| 196 | |
| 197 | |
| 198 | module_init(ixp4xx_wdt_init); |
| 199 | module_exit(ixp4xx_wdt_exit); |
| 200 | |
| 201 | MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>"); |
| 202 | MODULE_DESCRIPTION("IXP4xx Network Processor Watchdog"); |
| 203 | |
| 204 | module_param(heartbeat, int, 0); |
| 205 | MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds (default 60s)"); |
| 206 | |
Wim Van Sebroeck | 86a1e18 | 2012-03-05 16:51:11 +0100 | [diff] [blame] | 207 | module_param(nowayout, bool, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 208 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); |
| 209 | |
| 210 | MODULE_LICENSE("GPL"); |
| 211 | MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |
| 212 | |