Florian Fainelli | 04bf3b4 | 2007-05-06 12:55:32 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Driver for the MTX-1 Watchdog. |
| 3 | * |
| 4 | * (C) Copyright 2005 4G Systems <info@4g-systems.biz>, All Rights Reserved. |
| 5 | * http://www.4g-systems.biz |
| 6 | * |
| 7 | * (C) Copyright 2007 OpenWrt.org, Florian Fainelli <florian@openwrt.org> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU General Public License |
| 11 | * as published by the Free Software Foundation; either version |
| 12 | * 2 of the License, or (at your option) any later version. |
| 13 | * |
| 14 | * Neither Michael Stickel nor 4G Systems admit liability nor provide |
| 15 | * warranty for any of this software. This material is provided |
| 16 | * "AS-IS" and at no charge. |
| 17 | * |
| 18 | * (c) Copyright 2005 4G Systems <info@4g-systems.biz> |
| 19 | * |
| 20 | * Release 0.01. |
| 21 | * Author: Michael Stickel michael.stickel@4g-systems.biz |
| 22 | * |
| 23 | * Release 0.02. |
| 24 | * Author: Florian Fainelli florian@openwrt.org |
| 25 | * use the Linux watchdog/timer APIs |
| 26 | * |
| 27 | * The Watchdog is configured to reset the MTX-1 |
| 28 | * if it is not triggered for 100 seconds. |
| 29 | * It should not be triggered more often than 1.6 seconds. |
| 30 | * |
| 31 | * A timer triggers the watchdog every 5 seconds, until |
| 32 | * it is opened for the first time. After the first open |
| 33 | * it MUST be triggered every 2..95 seconds. |
| 34 | */ |
| 35 | |
| 36 | #include <linux/module.h> |
| 37 | #include <linux/moduleparam.h> |
| 38 | #include <linux/types.h> |
| 39 | #include <linux/errno.h> |
| 40 | #include <linux/miscdevice.h> |
| 41 | #include <linux/fs.h> |
| 42 | #include <linux/init.h> |
| 43 | #include <linux/ioport.h> |
| 44 | #include <linux/timer.h> |
| 45 | #include <linux/completion.h> |
| 46 | #include <linux/jiffies.h> |
| 47 | #include <linux/watchdog.h> |
| 48 | #include <asm/io.h> |
| 49 | #include <asm/uaccess.h> |
| 50 | |
| 51 | #include <asm/mach-au1x00/au1000.h> |
| 52 | |
| 53 | #define MTX1_WDT_INTERVAL (5 * HZ) |
| 54 | |
| 55 | static int ticks = 100 * HZ; |
| 56 | |
| 57 | static struct { |
| 58 | struct completion stop; |
| 59 | volatile int running; |
| 60 | struct timer_list timer; |
| 61 | volatile int queue; |
| 62 | int default_ticks; |
| 63 | unsigned long inuse; |
| 64 | } mtx1_wdt_device; |
| 65 | |
| 66 | static void mtx1_wdt_trigger(unsigned long unused) |
| 67 | { |
| 68 | u32 tmp; |
| 69 | |
| 70 | if (mtx1_wdt_device.running) |
| 71 | ticks--; |
| 72 | /* |
| 73 | * toggle GPIO2_15 |
| 74 | */ |
| 75 | tmp = au_readl(GPIO2_DIR); |
| 76 | tmp = (tmp & ~(1<<15)) | ((~tmp) & (1<<15)); |
| 77 | au_writel (tmp, GPIO2_DIR); |
| 78 | |
| 79 | if (mtx1_wdt_device.queue && ticks) |
| 80 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); |
| 81 | else { |
| 82 | complete(&mtx1_wdt_device.stop); |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | static void mtx1_wdt_reset(void) |
| 87 | { |
| 88 | ticks = mtx1_wdt_device.default_ticks; |
| 89 | } |
| 90 | |
| 91 | |
| 92 | static void mtx1_wdt_start(void) |
| 93 | { |
| 94 | if (!mtx1_wdt_device.queue) { |
| 95 | mtx1_wdt_device.queue = 1; |
| 96 | au_writel (au_readl(GPIO2_DIR) | (u32)(1<<15), GPIO2_DIR); |
| 97 | mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL); |
| 98 | } |
| 99 | mtx1_wdt_device.running++; |
| 100 | } |
| 101 | |
| 102 | static int mtx1_wdt_stop(void) |
| 103 | { |
| 104 | if (mtx1_wdt_device.queue) { |
| 105 | mtx1_wdt_device.queue = 0; |
| 106 | au_writel (au_readl(GPIO2_DIR) & ~((u32)(1<<15)), GPIO2_DIR); |
| 107 | } |
| 108 | |
| 109 | ticks = mtx1_wdt_device.default_ticks; |
| 110 | |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | /* Filesystem functions */ |
| 115 | |
| 116 | static int mtx1_wdt_open(struct inode *inode, struct file *file) |
| 117 | { |
| 118 | if (test_and_set_bit(0, &mtx1_wdt_device.inuse)) |
| 119 | return -EBUSY; |
| 120 | |
| 121 | return nonseekable_open(inode, file); |
| 122 | } |
| 123 | |
| 124 | |
| 125 | static int mtx1_wdt_release(struct inode *inode, struct file *file) |
| 126 | { |
| 127 | clear_bit(0, &mtx1_wdt_device.inuse); |
| 128 | return 0; |
| 129 | } |
| 130 | |
| 131 | static int mtx1_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) |
| 132 | { |
| 133 | void __user *argp = (void __user *)arg; |
| 134 | unsigned int value; |
| 135 | static struct watchdog_info ident = |
| 136 | { |
| 137 | .options = WDIOF_CARDRESET, |
| 138 | .identity = "MTX-1 WDT", |
| 139 | }; |
| 140 | |
| 141 | switch(cmd) { |
| 142 | case WDIOC_KEEPALIVE: |
| 143 | mtx1_wdt_reset(); |
| 144 | break; |
| 145 | case WDIOC_GETSTATUS: |
Wim Van Sebroeck | 5c4eb61 | 2007-07-21 13:42:18 +0000 | [diff] [blame] | 146 | case WDIOC_GETBOOTSTATUS: |
Florian Fainelli | 04bf3b4 | 2007-05-06 12:55:32 +0200 | [diff] [blame] | 147 | if ( copy_to_user(argp, &value, sizeof(int)) ) |
| 148 | return -EFAULT; |
| 149 | break; |
| 150 | case WDIOC_GETSUPPORT: |
| 151 | if ( copy_to_user(argp, &ident, sizeof(ident)) ) |
| 152 | return -EFAULT; |
| 153 | break; |
| 154 | case WDIOC_SETOPTIONS: |
| 155 | if ( copy_from_user(&value, argp, sizeof(int)) ) |
| 156 | return -EFAULT; |
| 157 | switch(value) { |
| 158 | case WDIOS_ENABLECARD: |
| 159 | mtx1_wdt_start(); |
| 160 | break; |
| 161 | case WDIOS_DISABLECARD: |
| 162 | return mtx1_wdt_stop(); |
| 163 | default: |
| 164 | return -EINVAL; |
| 165 | } |
| 166 | break; |
| 167 | default: |
| 168 | return -ENOTTY; |
| 169 | } |
| 170 | return 0; |
| 171 | } |
| 172 | |
| 173 | |
| 174 | static ssize_t mtx1_wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos) |
| 175 | { |
| 176 | if (!count) |
| 177 | return -EIO; |
| 178 | |
| 179 | mtx1_wdt_reset(); |
| 180 | return count; |
| 181 | } |
| 182 | |
| 183 | static struct file_operations mtx1_wdt_fops = { |
| 184 | .owner = THIS_MODULE, |
| 185 | .llseek = no_llseek, |
| 186 | .ioctl = mtx1_wdt_ioctl, |
| 187 | .open = mtx1_wdt_open, |
| 188 | .write = mtx1_wdt_write, |
| 189 | .release = mtx1_wdt_release |
| 190 | }; |
| 191 | |
| 192 | |
| 193 | static struct miscdevice mtx1_wdt_misc = { |
| 194 | .minor = WATCHDOG_MINOR, |
| 195 | .name = "watchdog", |
| 196 | .fops = &mtx1_wdt_fops |
| 197 | }; |
| 198 | |
| 199 | |
| 200 | static int __init mtx1_wdt_init(void) |
| 201 | { |
| 202 | int ret; |
| 203 | |
| 204 | if ((ret = misc_register(&mtx1_wdt_misc)) < 0) { |
| 205 | printk(KERN_ERR " mtx-1_wdt : failed to register\n"); |
| 206 | return ret; |
| 207 | } |
| 208 | |
| 209 | init_completion(&mtx1_wdt_device.stop); |
| 210 | mtx1_wdt_device.queue = 0; |
| 211 | |
| 212 | clear_bit(0, &mtx1_wdt_device.inuse); |
| 213 | |
| 214 | setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L); |
| 215 | |
| 216 | mtx1_wdt_device.default_ticks = ticks; |
| 217 | |
| 218 | mtx1_wdt_start(); |
| 219 | |
| 220 | printk(KERN_INFO "MTX-1 Watchdog driver\n"); |
| 221 | |
| 222 | return 0; |
| 223 | } |
| 224 | |
| 225 | static void __exit mtx1_wdt_exit(void) |
| 226 | { |
| 227 | if (mtx1_wdt_device.queue) { |
| 228 | mtx1_wdt_device.queue = 0; |
| 229 | wait_for_completion(&mtx1_wdt_device.stop); |
| 230 | } |
| 231 | misc_deregister(&mtx1_wdt_misc); |
| 232 | } |
| 233 | |
| 234 | module_init(mtx1_wdt_init); |
| 235 | module_exit(mtx1_wdt_exit); |
| 236 | |
| 237 | MODULE_AUTHOR("Michael Stickel, Florian Fainelli"); |
| 238 | MODULE_DESCRIPTION("Driver for the MTX-1 watchdog"); |
| 239 | MODULE_LICENSE("GPL"); |