1d0173278SGuenter Roeck // SPDX-License-Identifier: GPL-2.0+ 2b7e04f8cSWim Van Sebroeck /* 304bedfa5SAlan Cox * Industrial Computer Source WDT501 driver 4b7e04f8cSWim Van Sebroeck * 529fa0586SAlan Cox * (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>, 629fa0586SAlan Cox * All Rights Reserved. 7b7e04f8cSWim Van Sebroeck * 8b7e04f8cSWim Van Sebroeck * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide 9b7e04f8cSWim Van Sebroeck * warranty for any of this software. This material is provided 10b7e04f8cSWim Van Sebroeck * "AS-IS" and at no charge. 11b7e04f8cSWim Van Sebroeck * 12b7e04f8cSWim Van Sebroeck * (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk> 13b7e04f8cSWim Van Sebroeck * 14b7e04f8cSWim Van Sebroeck * Release 0.10. 15b7e04f8cSWim Van Sebroeck * 16b7e04f8cSWim Van Sebroeck * Fixes 17b7e04f8cSWim Van Sebroeck * Dave Gregorich : Modularisation and minor bugs 18b7e04f8cSWim Van Sebroeck * Alan Cox : Added the watchdog ioctl() stuff 19b7e04f8cSWim Van Sebroeck * Alan Cox : Fixed the reboot problem (as noted by 20b7e04f8cSWim Van Sebroeck * Matt Crocker). 21b7e04f8cSWim Van Sebroeck * Alan Cox : Added wdt= boot option 22b7e04f8cSWim Van Sebroeck * Alan Cox : Cleaned up copy/user stuff 239f2d1f0dSAlan Cox * Tim Hockin : Added insmod parameters, comment 249f2d1f0dSAlan Cox * cleanup, parameterized timeout 259f2d1f0dSAlan Cox * Tigran Aivazian : Restructured wdt_init() to handle 269f2d1f0dSAlan Cox * failures 27b7e04f8cSWim Van Sebroeck * Joel Becker : Added WDIOC_GET/SETTIMEOUT 28b7e04f8cSWim Van Sebroeck * Matt Domsch : Added nowayout module option 29b7e04f8cSWim Van Sebroeck */ 30b7e04f8cSWim Van Sebroeck 3127c766aaSJoe Perches #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 3227c766aaSJoe Perches 33b7e04f8cSWim Van Sebroeck #include <linux/interrupt.h> 34b7e04f8cSWim Van Sebroeck #include <linux/module.h> 35b7e04f8cSWim Van Sebroeck #include <linux/moduleparam.h> 36b7e04f8cSWim Van Sebroeck #include <linux/types.h> 37b7e04f8cSWim Van Sebroeck #include <linux/miscdevice.h> 38b7e04f8cSWim Van Sebroeck #include <linux/watchdog.h> 39b7e04f8cSWim Van Sebroeck #include <linux/fs.h> 40b7e04f8cSWim Van Sebroeck #include <linux/ioport.h> 41b7e04f8cSWim Van Sebroeck #include <linux/notifier.h> 42b7e04f8cSWim Van Sebroeck #include <linux/reboot.h> 43b7e04f8cSWim Van Sebroeck #include <linux/init.h> 449f2d1f0dSAlan Cox #include <linux/io.h> 459f2d1f0dSAlan Cox #include <linux/uaccess.h> 46b7e04f8cSWim Van Sebroeck 47b7e04f8cSWim Van Sebroeck #include "wd501p.h" 48b7e04f8cSWim Van Sebroeck 49b7e04f8cSWim Van Sebroeck static unsigned long wdt_is_open; 50b7e04f8cSWim Van Sebroeck static char expect_close; 51b7e04f8cSWim Van Sebroeck 52b7e04f8cSWim Van Sebroeck /* 53b7e04f8cSWim Van Sebroeck * Module parameters 54b7e04f8cSWim Van Sebroeck */ 55b7e04f8cSWim Van Sebroeck 56b7e04f8cSWim Van Sebroeck #define WD_TIMO 60 /* Default heartbeat = 60 seconds */ 57b7e04f8cSWim Van Sebroeck 58b7e04f8cSWim Van Sebroeck static int heartbeat = WD_TIMO; 59b7e04f8cSWim Van Sebroeck static int wd_heartbeat; 60b7e04f8cSWim Van Sebroeck module_param(heartbeat, int, 0); 619f2d1f0dSAlan Cox MODULE_PARM_DESC(heartbeat, 629f2d1f0dSAlan Cox "Watchdog heartbeat in seconds. (0 < heartbeat < 65536, default=" 639f2d1f0dSAlan Cox __MODULE_STRING(WD_TIMO) ")"); 64b7e04f8cSWim Van Sebroeck 6586a1e189SWim Van Sebroeck static bool nowayout = WATCHDOG_NOWAYOUT; 6686a1e189SWim Van Sebroeck module_param(nowayout, bool, 0); 679f2d1f0dSAlan Cox MODULE_PARM_DESC(nowayout, 689f2d1f0dSAlan Cox "Watchdog cannot be stopped once started (default=" 699f2d1f0dSAlan Cox __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 70b7e04f8cSWim Van Sebroeck 71b7e04f8cSWim Van Sebroeck /* You must set these - there is no sane way to probe for this board. */ 72b7e04f8cSWim Van Sebroeck static int io = 0x240; 73b7e04f8cSWim Van Sebroeck static int irq = 11; 74b7e04f8cSWim Van Sebroeck 7501c785dcSAlan Cox static DEFINE_SPINLOCK(wdt_lock); 7601c785dcSAlan Cox 775d1c93ceSDavid Howells module_param_hw(io, int, ioport, 0); 78b7e04f8cSWim Van Sebroeck MODULE_PARM_DESC(io, "WDT io port (default=0x240)"); 795d1c93ceSDavid Howells module_param_hw(irq, int, irq, 0); 80b7e04f8cSWim Van Sebroeck MODULE_PARM_DESC(irq, "WDT irq (default=11)"); 81b7e04f8cSWim Van Sebroeck 82b7e04f8cSWim Van Sebroeck /* Support for the Fan Tachometer on the WDT501-P */ 83b7e04f8cSWim Van Sebroeck static int tachometer; 84b7e04f8cSWim Van Sebroeck module_param(tachometer, int, 0); 859f2d1f0dSAlan Cox MODULE_PARM_DESC(tachometer, 869f2d1f0dSAlan Cox "WDT501-P Fan Tachometer support (0=disable, default=0)"); 8704bedfa5SAlan Cox 8804bedfa5SAlan Cox static int type = 500; 8904bedfa5SAlan Cox module_param(type, int, 0); 9004bedfa5SAlan Cox MODULE_PARM_DESC(type, 9104bedfa5SAlan Cox "WDT501-P Card type (500 or 501, default=500)"); 92b7e04f8cSWim Van Sebroeck 93b7e04f8cSWim Van Sebroeck /* 94b7e04f8cSWim Van Sebroeck * Programming support 95b7e04f8cSWim Van Sebroeck */ 96b7e04f8cSWim Van Sebroeck 97b7e04f8cSWim Van Sebroeck static void wdt_ctr_mode(int ctr, int mode) 98b7e04f8cSWim Van Sebroeck { 99b7e04f8cSWim Van Sebroeck ctr <<= 6; 100b7e04f8cSWim Van Sebroeck ctr |= 0x30; 101b7e04f8cSWim Van Sebroeck ctr |= (mode << 1); 102b7e04f8cSWim Van Sebroeck outb_p(ctr, WDT_CR); 103b7e04f8cSWim Van Sebroeck } 104b7e04f8cSWim Van Sebroeck 105b7e04f8cSWim Van Sebroeck static void wdt_ctr_load(int ctr, int val) 106b7e04f8cSWim Van Sebroeck { 107b7e04f8cSWim Van Sebroeck outb_p(val&0xFF, WDT_COUNT0+ctr); 108b7e04f8cSWim Van Sebroeck outb_p(val>>8, WDT_COUNT0+ctr); 109b7e04f8cSWim Van Sebroeck } 110b7e04f8cSWim Van Sebroeck 111b7e04f8cSWim Van Sebroeck /** 112b7e04f8cSWim Van Sebroeck * wdt_start: 113b7e04f8cSWim Van Sebroeck * 114b7e04f8cSWim Van Sebroeck * Start the watchdog driver. 115b7e04f8cSWim Van Sebroeck */ 116b7e04f8cSWim Van Sebroeck 117b7e04f8cSWim Van Sebroeck static int wdt_start(void) 118b7e04f8cSWim Van Sebroeck { 11901c785dcSAlan Cox unsigned long flags; 12001c785dcSAlan Cox spin_lock_irqsave(&wdt_lock, flags); 121b7e04f8cSWim Van Sebroeck inb_p(WDT_DC); /* Disable watchdog */ 1229f2d1f0dSAlan Cox wdt_ctr_mode(0, 3); /* Program CTR0 for Mode 3: 1239f2d1f0dSAlan Cox Square Wave Generator */ 1249f2d1f0dSAlan Cox wdt_ctr_mode(1, 2); /* Program CTR1 for Mode 2: 1259f2d1f0dSAlan Cox Rate Generator */ 1269f2d1f0dSAlan Cox wdt_ctr_mode(2, 0); /* Program CTR2 for Mode 0: 1279f2d1f0dSAlan Cox Pulse on Terminal Count */ 128b7e04f8cSWim Van Sebroeck wdt_ctr_load(0, 8948); /* Count at 100Hz */ 129b7e04f8cSWim Van Sebroeck wdt_ctr_load(1, wd_heartbeat); /* Heartbeat */ 130b7e04f8cSWim Van Sebroeck wdt_ctr_load(2, 65535); /* Length of reset pulse */ 131b7e04f8cSWim Van Sebroeck outb_p(0, WDT_DC); /* Enable watchdog */ 13201c785dcSAlan Cox spin_unlock_irqrestore(&wdt_lock, flags); 133b7e04f8cSWim Van Sebroeck return 0; 134b7e04f8cSWim Van Sebroeck } 135b7e04f8cSWim Van Sebroeck 136b7e04f8cSWim Van Sebroeck /** 137b7e04f8cSWim Van Sebroeck * wdt_stop: 138b7e04f8cSWim Van Sebroeck * 139b7e04f8cSWim Van Sebroeck * Stop the watchdog driver. 140b7e04f8cSWim Van Sebroeck */ 141b7e04f8cSWim Van Sebroeck 142b7e04f8cSWim Van Sebroeck static int wdt_stop(void) 143b7e04f8cSWim Van Sebroeck { 14401c785dcSAlan Cox unsigned long flags; 14501c785dcSAlan Cox spin_lock_irqsave(&wdt_lock, flags); 146b7e04f8cSWim Van Sebroeck /* Turn the card off */ 147b7e04f8cSWim Van Sebroeck inb_p(WDT_DC); /* Disable watchdog */ 148b7e04f8cSWim Van Sebroeck wdt_ctr_load(2, 0); /* 0 length reset pulses now */ 14901c785dcSAlan Cox spin_unlock_irqrestore(&wdt_lock, flags); 150b7e04f8cSWim Van Sebroeck return 0; 151b7e04f8cSWim Van Sebroeck } 152b7e04f8cSWim Van Sebroeck 153b7e04f8cSWim Van Sebroeck /** 154b7e04f8cSWim Van Sebroeck * wdt_ping: 155b7e04f8cSWim Van Sebroeck * 1569f2d1f0dSAlan Cox * Reload counter one with the watchdog heartbeat. We don't bother 1579f2d1f0dSAlan Cox * reloading the cascade counter. 158b7e04f8cSWim Van Sebroeck */ 159b7e04f8cSWim Van Sebroeck 16004bedfa5SAlan Cox static void wdt_ping(void) 161b7e04f8cSWim Van Sebroeck { 16201c785dcSAlan Cox unsigned long flags; 16301c785dcSAlan Cox spin_lock_irqsave(&wdt_lock, flags); 164b7e04f8cSWim Van Sebroeck /* Write a watchdog value */ 165b7e04f8cSWim Van Sebroeck inb_p(WDT_DC); /* Disable watchdog */ 1669f2d1f0dSAlan Cox wdt_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2: 1679f2d1f0dSAlan Cox Rate Generator */ 168b7e04f8cSWim Van Sebroeck wdt_ctr_load(1, wd_heartbeat); /* Heartbeat */ 169b7e04f8cSWim Van Sebroeck outb_p(0, WDT_DC); /* Enable watchdog */ 17001c785dcSAlan Cox spin_unlock_irqrestore(&wdt_lock, flags); 171b7e04f8cSWim Van Sebroeck } 172b7e04f8cSWim Van Sebroeck 173b7e04f8cSWim Van Sebroeck /** 174b7e04f8cSWim Van Sebroeck * wdt_set_heartbeat: 175b7e04f8cSWim Van Sebroeck * @t: the new heartbeat value that needs to be set. 176b7e04f8cSWim Van Sebroeck * 1779f2d1f0dSAlan Cox * Set a new heartbeat value for the watchdog device. If the heartbeat 1789f2d1f0dSAlan Cox * value is incorrect we keep the old value and return -EINVAL. If 1799f2d1f0dSAlan Cox * successful we return 0. 180b7e04f8cSWim Van Sebroeck */ 1819f2d1f0dSAlan Cox 182b7e04f8cSWim Van Sebroeck static int wdt_set_heartbeat(int t) 183b7e04f8cSWim Van Sebroeck { 1849f2d1f0dSAlan Cox if (t < 1 || t > 65535) 185b7e04f8cSWim Van Sebroeck return -EINVAL; 186b7e04f8cSWim Van Sebroeck 187b7e04f8cSWim Van Sebroeck heartbeat = t; 188b7e04f8cSWim Van Sebroeck wd_heartbeat = t * 100; 189b7e04f8cSWim Van Sebroeck return 0; 190b7e04f8cSWim Van Sebroeck } 191b7e04f8cSWim Van Sebroeck 192b7e04f8cSWim Van Sebroeck /** 193b7e04f8cSWim Van Sebroeck * wdt_get_status: 194b7e04f8cSWim Van Sebroeck * 195b7e04f8cSWim Van Sebroeck * Extract the status information from a WDT watchdog device. There are 196b7e04f8cSWim Van Sebroeck * several board variants so we have to know which bits are valid. Some 197b7e04f8cSWim Van Sebroeck * bits default to one and some to zero in order to be maximally painful. 198b7e04f8cSWim Van Sebroeck * 199b7e04f8cSWim Van Sebroeck * we then map the bits onto the status ioctl flags. 200b7e04f8cSWim Van Sebroeck */ 201b7e04f8cSWim Van Sebroeck 20204bedfa5SAlan Cox static int wdt_get_status(void) 203b7e04f8cSWim Van Sebroeck { 20401c785dcSAlan Cox unsigned char new_status; 20504bedfa5SAlan Cox int status = 0; 20601c785dcSAlan Cox unsigned long flags; 20701c785dcSAlan Cox 20801c785dcSAlan Cox spin_lock_irqsave(&wdt_lock, flags); 20901c785dcSAlan Cox new_status = inb_p(WDT_SR); 21001c785dcSAlan Cox spin_unlock_irqrestore(&wdt_lock, flags); 211b7e04f8cSWim Van Sebroeck 212b7e04f8cSWim Van Sebroeck if (new_status & WDC_SR_ISOI0) 21304bedfa5SAlan Cox status |= WDIOF_EXTERN1; 214b7e04f8cSWim Van Sebroeck if (new_status & WDC_SR_ISII1) 21504bedfa5SAlan Cox status |= WDIOF_EXTERN2; 21604bedfa5SAlan Cox if (type == 501) { 217b7e04f8cSWim Van Sebroeck if (!(new_status & WDC_SR_TGOOD)) 21804bedfa5SAlan Cox status |= WDIOF_OVERHEAT; 219b7e04f8cSWim Van Sebroeck if (!(new_status & WDC_SR_PSUOVER)) 22004bedfa5SAlan Cox status |= WDIOF_POWEROVER; 221b7e04f8cSWim Van Sebroeck if (!(new_status & WDC_SR_PSUUNDR)) 22204bedfa5SAlan Cox status |= WDIOF_POWERUNDER; 223b7e04f8cSWim Van Sebroeck if (tachometer) { 224b7e04f8cSWim Van Sebroeck if (!(new_status & WDC_SR_FANGOOD)) 22504bedfa5SAlan Cox status |= WDIOF_FANFAULT; 226b7e04f8cSWim Van Sebroeck } 22704bedfa5SAlan Cox } 22804bedfa5SAlan Cox return status; 229b7e04f8cSWim Van Sebroeck } 230b7e04f8cSWim Van Sebroeck 231b7e04f8cSWim Van Sebroeck /** 232b7e04f8cSWim Van Sebroeck * wdt_get_temperature: 233b7e04f8cSWim Van Sebroeck * 234b7e04f8cSWim Van Sebroeck * Reports the temperature in degrees Fahrenheit. The API is in 235b7e04f8cSWim Van Sebroeck * farenheit. It was designed by an imperial measurement luddite. 236b7e04f8cSWim Van Sebroeck */ 237b7e04f8cSWim Van Sebroeck 23804bedfa5SAlan Cox static int wdt_get_temperature(void) 239b7e04f8cSWim Van Sebroeck { 24001c785dcSAlan Cox unsigned short c; 24101c785dcSAlan Cox unsigned long flags; 242b7e04f8cSWim Van Sebroeck 24301c785dcSAlan Cox spin_lock_irqsave(&wdt_lock, flags); 24401c785dcSAlan Cox c = inb_p(WDT_RT); 24501c785dcSAlan Cox spin_unlock_irqrestore(&wdt_lock, flags); 24604bedfa5SAlan Cox return (c * 11 / 15) + 7; 247b7e04f8cSWim Van Sebroeck } 24804bedfa5SAlan Cox 24904bedfa5SAlan Cox static void wdt_decode_501(int status) 25004bedfa5SAlan Cox { 25104bedfa5SAlan Cox if (!(status & WDC_SR_TGOOD)) 25227c766aaSJoe Perches pr_crit("Overheat alarm (%d)\n", inb_p(WDT_RT)); 25304bedfa5SAlan Cox if (!(status & WDC_SR_PSUOVER)) 25427c766aaSJoe Perches pr_crit("PSU over voltage\n"); 25504bedfa5SAlan Cox if (!(status & WDC_SR_PSUUNDR)) 25627c766aaSJoe Perches pr_crit("PSU under voltage\n"); 25704bedfa5SAlan Cox } 258b7e04f8cSWim Van Sebroeck 259b7e04f8cSWim Van Sebroeck /** 260b7e04f8cSWim Van Sebroeck * wdt_interrupt: 261b7e04f8cSWim Van Sebroeck * @irq: Interrupt number 262b7e04f8cSWim Van Sebroeck * @dev_id: Unused as we don't allow multiple devices. 263b7e04f8cSWim Van Sebroeck * 264b7e04f8cSWim Van Sebroeck * Handle an interrupt from the board. These are raised when the status 265b7e04f8cSWim Van Sebroeck * map changes in what the board considers an interesting way. That means 266b7e04f8cSWim Van Sebroeck * a failure condition occurring. 267b7e04f8cSWim Van Sebroeck */ 268b7e04f8cSWim Van Sebroeck 269b7e04f8cSWim Van Sebroeck static irqreturn_t wdt_interrupt(int irq, void *dev_id) 270b7e04f8cSWim Van Sebroeck { 271b7e04f8cSWim Van Sebroeck /* 272b7e04f8cSWim Van Sebroeck * Read the status register see what is up and 273b7e04f8cSWim Van Sebroeck * then printk it. 274b7e04f8cSWim Van Sebroeck */ 27501c785dcSAlan Cox unsigned char status; 27601c785dcSAlan Cox 27701c785dcSAlan Cox spin_lock(&wdt_lock); 27801c785dcSAlan Cox status = inb_p(WDT_SR); 279b7e04f8cSWim Van Sebroeck 28027c766aaSJoe Perches pr_crit("WDT status %d\n", status); 281b7e04f8cSWim Van Sebroeck 28204bedfa5SAlan Cox if (type == 501) { 28304bedfa5SAlan Cox wdt_decode_501(status); 284b7e04f8cSWim Van Sebroeck if (tachometer) { 285b7e04f8cSWim Van Sebroeck if (!(status & WDC_SR_FANGOOD)) 28627c766aaSJoe Perches pr_crit("Possible fan fault\n"); 287b7e04f8cSWim Van Sebroeck } 28804bedfa5SAlan Cox } 28959338d4cSIlpo Jarvinen if (!(status & WDC_SR_WCCR)) { 290b7e04f8cSWim Van Sebroeck #ifdef SOFTWARE_REBOOT 291b7e04f8cSWim Van Sebroeck #ifdef ONLY_TESTING 29227c766aaSJoe Perches pr_crit("Would Reboot\n"); 293b7e04f8cSWim Van Sebroeck #else 29427c766aaSJoe Perches pr_crit("Initiating system reboot\n"); 295b7e04f8cSWim Van Sebroeck emergency_restart(); 296b7e04f8cSWim Van Sebroeck #endif 297b7e04f8cSWim Van Sebroeck #else 29827c766aaSJoe Perches pr_crit("Reset in 5ms\n"); 299b7e04f8cSWim Van Sebroeck #endif 30059338d4cSIlpo Jarvinen } 30101c785dcSAlan Cox spin_unlock(&wdt_lock); 302b7e04f8cSWim Van Sebroeck return IRQ_HANDLED; 303b7e04f8cSWim Van Sebroeck } 304b7e04f8cSWim Van Sebroeck 305b7e04f8cSWim Van Sebroeck 306b7e04f8cSWim Van Sebroeck /** 307b7e04f8cSWim Van Sebroeck * wdt_write: 308b7e04f8cSWim Van Sebroeck * @file: file handle to the watchdog 309b7e04f8cSWim Van Sebroeck * @buf: buffer to write (unused as data does not matter here 310b7e04f8cSWim Van Sebroeck * @count: count of bytes 311b7e04f8cSWim Van Sebroeck * @ppos: pointer to the position to write. No seeks allowed 312b7e04f8cSWim Van Sebroeck * 313b7e04f8cSWim Van Sebroeck * A write to a watchdog device is defined as a keepalive signal. Any 314b7e04f8cSWim Van Sebroeck * write of data will do, as we we don't define content meaning. 315b7e04f8cSWim Van Sebroeck */ 316b7e04f8cSWim Van Sebroeck 3179f2d1f0dSAlan Cox static ssize_t wdt_write(struct file *file, const char __user *buf, 3189f2d1f0dSAlan Cox size_t count, loff_t *ppos) 319b7e04f8cSWim Van Sebroeck { 320b7e04f8cSWim Van Sebroeck if (count) { 321b7e04f8cSWim Van Sebroeck if (!nowayout) { 322b7e04f8cSWim Van Sebroeck size_t i; 323b7e04f8cSWim Van Sebroeck 324b7e04f8cSWim Van Sebroeck /* In case it was set long ago */ 325b7e04f8cSWim Van Sebroeck expect_close = 0; 326b7e04f8cSWim Van Sebroeck 327b7e04f8cSWim Van Sebroeck for (i = 0; i != count; i++) { 328b7e04f8cSWim Van Sebroeck char c; 329b7e04f8cSWim Van Sebroeck if (get_user(c, buf + i)) 330b7e04f8cSWim Van Sebroeck return -EFAULT; 331b7e04f8cSWim Van Sebroeck if (c == 'V') 332b7e04f8cSWim Van Sebroeck expect_close = 42; 333b7e04f8cSWim Van Sebroeck } 334b7e04f8cSWim Van Sebroeck } 335b7e04f8cSWim Van Sebroeck wdt_ping(); 336b7e04f8cSWim Van Sebroeck } 337b7e04f8cSWim Van Sebroeck return count; 338b7e04f8cSWim Van Sebroeck } 339b7e04f8cSWim Van Sebroeck 340b7e04f8cSWim Van Sebroeck /** 341b7e04f8cSWim Van Sebroeck * wdt_ioctl: 342b7e04f8cSWim Van Sebroeck * @file: file handle to the device 343b7e04f8cSWim Van Sebroeck * @cmd: watchdog command 344b7e04f8cSWim Van Sebroeck * @arg: argument pointer 345b7e04f8cSWim Van Sebroeck * 346b7e04f8cSWim Van Sebroeck * The watchdog API defines a common set of functions for all watchdogs 347b7e04f8cSWim Van Sebroeck * according to their available features. We only actually usefully support 348b7e04f8cSWim Van Sebroeck * querying capabilities and current status. 349b7e04f8cSWim Van Sebroeck */ 350b7e04f8cSWim Van Sebroeck 3519f2d1f0dSAlan Cox static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 352b7e04f8cSWim Van Sebroeck { 353b7e04f8cSWim Van Sebroeck void __user *argp = (void __user *)arg; 354b7e04f8cSWim Van Sebroeck int __user *p = argp; 355b7e04f8cSWim Van Sebroeck int new_heartbeat; 356b7e04f8cSWim Van Sebroeck int status; 357b7e04f8cSWim Van Sebroeck 358c1bf3acfSAndrew Morton struct watchdog_info ident = { 359b7e04f8cSWim Van Sebroeck .options = WDIOF_SETTIMEOUT| 360b7e04f8cSWim Van Sebroeck WDIOF_MAGICCLOSE| 361b7e04f8cSWim Van Sebroeck WDIOF_KEEPALIVEPING, 362b7e04f8cSWim Van Sebroeck .firmware_version = 1, 363b7e04f8cSWim Van Sebroeck .identity = "WDT500/501", 364b7e04f8cSWim Van Sebroeck }; 365b7e04f8cSWim Van Sebroeck 366b7e04f8cSWim Van Sebroeck /* Add options according to the card we have */ 367b7e04f8cSWim Van Sebroeck ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2); 36804bedfa5SAlan Cox if (type == 501) { 36904bedfa5SAlan Cox ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER| 37004bedfa5SAlan Cox WDIOF_POWEROVER); 371b7e04f8cSWim Van Sebroeck if (tachometer) 372b7e04f8cSWim Van Sebroeck ident.options |= WDIOF_FANFAULT; 37304bedfa5SAlan Cox } 374b7e04f8cSWim Van Sebroeck 3759f2d1f0dSAlan Cox switch (cmd) { 376b7e04f8cSWim Van Sebroeck case WDIOC_GETSUPPORT: 377b7e04f8cSWim Van Sebroeck return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; 378b7e04f8cSWim Van Sebroeck case WDIOC_GETSTATUS: 37904bedfa5SAlan Cox status = wdt_get_status(); 380b7e04f8cSWim Van Sebroeck return put_user(status, p); 381b7e04f8cSWim Van Sebroeck case WDIOC_GETBOOTSTATUS: 382b7e04f8cSWim Van Sebroeck return put_user(0, p); 383b7e04f8cSWim Van Sebroeck case WDIOC_KEEPALIVE: 384b7e04f8cSWim Van Sebroeck wdt_ping(); 385b7e04f8cSWim Van Sebroeck return 0; 386b7e04f8cSWim Van Sebroeck case WDIOC_SETTIMEOUT: 387b7e04f8cSWim Van Sebroeck if (get_user(new_heartbeat, p)) 388b7e04f8cSWim Van Sebroeck return -EFAULT; 389b7e04f8cSWim Van Sebroeck if (wdt_set_heartbeat(new_heartbeat)) 390b7e04f8cSWim Van Sebroeck return -EINVAL; 391b7e04f8cSWim Van Sebroeck wdt_ping(); 392*bd490f82SGustavo A. R. Silva fallthrough; 393b7e04f8cSWim Van Sebroeck case WDIOC_GETTIMEOUT: 394b7e04f8cSWim Van Sebroeck return put_user(heartbeat, p); 3950c06090cSWim Van Sebroeck default: 3960c06090cSWim Van Sebroeck return -ENOTTY; 397b7e04f8cSWim Van Sebroeck } 398b7e04f8cSWim Van Sebroeck } 399b7e04f8cSWim Van Sebroeck 400b7e04f8cSWim Van Sebroeck /** 401b7e04f8cSWim Van Sebroeck * wdt_open: 402b7e04f8cSWim Van Sebroeck * @inode: inode of device 403b7e04f8cSWim Van Sebroeck * @file: file handle to device 404b7e04f8cSWim Van Sebroeck * 405b7e04f8cSWim Van Sebroeck * The watchdog device has been opened. The watchdog device is single 406b7e04f8cSWim Van Sebroeck * open and on opening we load the counters. Counter zero is a 100Hz 407b7e04f8cSWim Van Sebroeck * cascade, into counter 1 which downcounts to reboot. When the counter 408b7e04f8cSWim Van Sebroeck * triggers counter 2 downcounts the length of the reset pulse which 409b7e04f8cSWim Van Sebroeck * set set to be as long as possible. 410b7e04f8cSWim Van Sebroeck */ 411b7e04f8cSWim Van Sebroeck 412b7e04f8cSWim Van Sebroeck static int wdt_open(struct inode *inode, struct file *file) 413b7e04f8cSWim Van Sebroeck { 414b7e04f8cSWim Van Sebroeck if (test_and_set_bit(0, &wdt_is_open)) 415b7e04f8cSWim Van Sebroeck return -EBUSY; 416b7e04f8cSWim Van Sebroeck /* 417b7e04f8cSWim Van Sebroeck * Activate 418b7e04f8cSWim Van Sebroeck */ 419b7e04f8cSWim Van Sebroeck wdt_start(); 420c5bf68feSKirill Smelkov return stream_open(inode, file); 421b7e04f8cSWim Van Sebroeck } 422b7e04f8cSWim Van Sebroeck 423b7e04f8cSWim Van Sebroeck /** 424b7e04f8cSWim Van Sebroeck * wdt_release: 425b7e04f8cSWim Van Sebroeck * @inode: inode to board 426b7e04f8cSWim Van Sebroeck * @file: file handle to board 427b7e04f8cSWim Van Sebroeck * 428b7e04f8cSWim Van Sebroeck * The watchdog has a configurable API. There is a religious dispute 429b7e04f8cSWim Van Sebroeck * between people who want their watchdog to be able to shut down and 430b7e04f8cSWim Van Sebroeck * those who want to be sure if the watchdog manager dies the machine 431b7e04f8cSWim Van Sebroeck * reboots. In the former case we disable the counters, in the latter 432b7e04f8cSWim Van Sebroeck * case you have to open it again very soon. 433b7e04f8cSWim Van Sebroeck */ 434b7e04f8cSWim Van Sebroeck 435b7e04f8cSWim Van Sebroeck static int wdt_release(struct inode *inode, struct file *file) 436b7e04f8cSWim Van Sebroeck { 437b7e04f8cSWim Van Sebroeck if (expect_close == 42) { 438b7e04f8cSWim Van Sebroeck wdt_stop(); 439b7e04f8cSWim Van Sebroeck clear_bit(0, &wdt_is_open); 440b7e04f8cSWim Van Sebroeck } else { 44127c766aaSJoe Perches pr_crit("WDT device closed unexpectedly. WDT will not stop!\n"); 442b7e04f8cSWim Van Sebroeck wdt_ping(); 443b7e04f8cSWim Van Sebroeck } 444b7e04f8cSWim Van Sebroeck expect_close = 0; 445b7e04f8cSWim Van Sebroeck return 0; 446b7e04f8cSWim Van Sebroeck } 447b7e04f8cSWim Van Sebroeck 448b7e04f8cSWim Van Sebroeck /** 449b7e04f8cSWim Van Sebroeck * wdt_temp_read: 450b7e04f8cSWim Van Sebroeck * @file: file handle to the watchdog board 451b7e04f8cSWim Van Sebroeck * @buf: buffer to write 1 byte into 452b7e04f8cSWim Van Sebroeck * @count: length of buffer 453b7e04f8cSWim Van Sebroeck * @ptr: offset (no seek allowed) 454b7e04f8cSWim Van Sebroeck * 455b7e04f8cSWim Van Sebroeck * Temp_read reports the temperature in degrees Fahrenheit. The API is in 456b7e04f8cSWim Van Sebroeck * farenheit. It was designed by an imperial measurement luddite. 457b7e04f8cSWim Van Sebroeck */ 458b7e04f8cSWim Van Sebroeck 4599f2d1f0dSAlan Cox static ssize_t wdt_temp_read(struct file *file, char __user *buf, 4609f2d1f0dSAlan Cox size_t count, loff_t *ptr) 461b7e04f8cSWim Van Sebroeck { 46204bedfa5SAlan Cox int temperature = wdt_get_temperature(); 463b7e04f8cSWim Van Sebroeck 464b7e04f8cSWim Van Sebroeck if (copy_to_user(buf, &temperature, 1)) 465b7e04f8cSWim Van Sebroeck return -EFAULT; 466b7e04f8cSWim Van Sebroeck 467b7e04f8cSWim Van Sebroeck return 1; 468b7e04f8cSWim Van Sebroeck } 469b7e04f8cSWim Van Sebroeck 470b7e04f8cSWim Van Sebroeck /** 471b7e04f8cSWim Van Sebroeck * wdt_temp_open: 472b7e04f8cSWim Van Sebroeck * @inode: inode of device 473b7e04f8cSWim Van Sebroeck * @file: file handle to device 474b7e04f8cSWim Van Sebroeck * 475b7e04f8cSWim Van Sebroeck * The temperature device has been opened. 476b7e04f8cSWim Van Sebroeck */ 477b7e04f8cSWim Van Sebroeck 478b7e04f8cSWim Van Sebroeck static int wdt_temp_open(struct inode *inode, struct file *file) 479b7e04f8cSWim Van Sebroeck { 480c5bf68feSKirill Smelkov return stream_open(inode, file); 481b7e04f8cSWim Van Sebroeck } 482b7e04f8cSWim Van Sebroeck 483b7e04f8cSWim Van Sebroeck /** 484b7e04f8cSWim Van Sebroeck * wdt_temp_release: 485b7e04f8cSWim Van Sebroeck * @inode: inode to board 486b7e04f8cSWim Van Sebroeck * @file: file handle to board 487b7e04f8cSWim Van Sebroeck * 488b7e04f8cSWim Van Sebroeck * The temperature device has been closed. 489b7e04f8cSWim Van Sebroeck */ 490b7e04f8cSWim Van Sebroeck 491b7e04f8cSWim Van Sebroeck static int wdt_temp_release(struct inode *inode, struct file *file) 492b7e04f8cSWim Van Sebroeck { 493b7e04f8cSWim Van Sebroeck return 0; 494b7e04f8cSWim Van Sebroeck } 495b7e04f8cSWim Van Sebroeck 496b7e04f8cSWim Van Sebroeck /** 497b7e04f8cSWim Van Sebroeck * notify_sys: 498b7e04f8cSWim Van Sebroeck * @this: our notifier block 499b7e04f8cSWim Van Sebroeck * @code: the event being reported 500b7e04f8cSWim Van Sebroeck * @unused: unused 501b7e04f8cSWim Van Sebroeck * 502b7e04f8cSWim Van Sebroeck * Our notifier is called on system shutdowns. We want to turn the card 503b7e04f8cSWim Van Sebroeck * off at reboot otherwise the machine will reboot again during memory 504b7e04f8cSWim Van Sebroeck * test or worse yet during the following fsck. This would suck, in fact 505b7e04f8cSWim Van Sebroeck * trust me - if it happens it does suck. 506b7e04f8cSWim Van Sebroeck */ 507b7e04f8cSWim Van Sebroeck 508b7e04f8cSWim Van Sebroeck static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 509b7e04f8cSWim Van Sebroeck void *unused) 510b7e04f8cSWim Van Sebroeck { 5119f2d1f0dSAlan Cox if (code == SYS_DOWN || code == SYS_HALT) 512b7e04f8cSWim Van Sebroeck wdt_stop(); 513b7e04f8cSWim Van Sebroeck return NOTIFY_DONE; 514b7e04f8cSWim Van Sebroeck } 515b7e04f8cSWim Van Sebroeck 516b7e04f8cSWim Van Sebroeck /* 517b7e04f8cSWim Van Sebroeck * Kernel Interfaces 518b7e04f8cSWim Van Sebroeck */ 519b7e04f8cSWim Van Sebroeck 520b7e04f8cSWim Van Sebroeck 521b7e04f8cSWim Van Sebroeck static const struct file_operations wdt_fops = { 522b7e04f8cSWim Van Sebroeck .owner = THIS_MODULE, 523b7e04f8cSWim Van Sebroeck .llseek = no_llseek, 524b7e04f8cSWim Van Sebroeck .write = wdt_write, 5259f2d1f0dSAlan Cox .unlocked_ioctl = wdt_ioctl, 526b6dfb247SArnd Bergmann .compat_ioctl = compat_ptr_ioctl, 527b7e04f8cSWim Van Sebroeck .open = wdt_open, 528b7e04f8cSWim Van Sebroeck .release = wdt_release, 529b7e04f8cSWim Van Sebroeck }; 530b7e04f8cSWim Van Sebroeck 531b7e04f8cSWim Van Sebroeck static struct miscdevice wdt_miscdev = { 532b7e04f8cSWim Van Sebroeck .minor = WATCHDOG_MINOR, 533b7e04f8cSWim Van Sebroeck .name = "watchdog", 534b7e04f8cSWim Van Sebroeck .fops = &wdt_fops, 535b7e04f8cSWim Van Sebroeck }; 536b7e04f8cSWim Van Sebroeck 537b7e04f8cSWim Van Sebroeck static const struct file_operations wdt_temp_fops = { 538b7e04f8cSWim Van Sebroeck .owner = THIS_MODULE, 539b7e04f8cSWim Van Sebroeck .llseek = no_llseek, 540b7e04f8cSWim Van Sebroeck .read = wdt_temp_read, 541b7e04f8cSWim Van Sebroeck .open = wdt_temp_open, 542b7e04f8cSWim Van Sebroeck .release = wdt_temp_release, 543b7e04f8cSWim Van Sebroeck }; 544b7e04f8cSWim Van Sebroeck 545b7e04f8cSWim Van Sebroeck static struct miscdevice temp_miscdev = { 546b7e04f8cSWim Van Sebroeck .minor = TEMP_MINOR, 547b7e04f8cSWim Van Sebroeck .name = "temperature", 548b7e04f8cSWim Van Sebroeck .fops = &wdt_temp_fops, 549b7e04f8cSWim Van Sebroeck }; 550b7e04f8cSWim Van Sebroeck 551b7e04f8cSWim Van Sebroeck /* 552b7e04f8cSWim Van Sebroeck * The WDT card needs to learn about soft shutdowns in order to 553b7e04f8cSWim Van Sebroeck * turn the timebomb registers off. 554b7e04f8cSWim Van Sebroeck */ 555b7e04f8cSWim Van Sebroeck 556b7e04f8cSWim Van Sebroeck static struct notifier_block wdt_notifier = { 557b7e04f8cSWim Van Sebroeck .notifier_call = wdt_notify_sys, 558b7e04f8cSWim Van Sebroeck }; 559b7e04f8cSWim Van Sebroeck 560b7e04f8cSWim Van Sebroeck /** 561b7e04f8cSWim Van Sebroeck * cleanup_module: 562b7e04f8cSWim Van Sebroeck * 563b7e04f8cSWim Van Sebroeck * Unload the watchdog. You cannot do this with any file handles open. 564b7e04f8cSWim Van Sebroeck * If your watchdog is set to continue ticking on close and you unload 565b7e04f8cSWim Van Sebroeck * it, well it keeps ticking. We won't get the interrupt but the board 566b7e04f8cSWim Van Sebroeck * will not touch PC memory so all is fine. You just have to load a new 567b7e04f8cSWim Van Sebroeck * module in 60 seconds or reboot. 568b7e04f8cSWim Van Sebroeck */ 569b7e04f8cSWim Van Sebroeck 570b7e04f8cSWim Van Sebroeck static void __exit wdt_exit(void) 571b7e04f8cSWim Van Sebroeck { 572b7e04f8cSWim Van Sebroeck misc_deregister(&wdt_miscdev); 57304bedfa5SAlan Cox if (type == 501) 574b7e04f8cSWim Van Sebroeck misc_deregister(&temp_miscdev); 575b7e04f8cSWim Van Sebroeck unregister_reboot_notifier(&wdt_notifier); 576b7e04f8cSWim Van Sebroeck free_irq(irq, NULL); 577b7e04f8cSWim Van Sebroeck release_region(io, 8); 578b7e04f8cSWim Van Sebroeck } 579b7e04f8cSWim Van Sebroeck 580b7e04f8cSWim Van Sebroeck /** 581b7e04f8cSWim Van Sebroeck * wdt_init: 582b7e04f8cSWim Van Sebroeck * 583b7e04f8cSWim Van Sebroeck * Set up the WDT watchdog board. All we have to do is grab the 584b7e04f8cSWim Van Sebroeck * resources we require and bitch if anyone beat us to them. 585b7e04f8cSWim Van Sebroeck * The open() function will actually kick the board off. 586b7e04f8cSWim Van Sebroeck */ 587b7e04f8cSWim Van Sebroeck 588b7e04f8cSWim Van Sebroeck static int __init wdt_init(void) 589b7e04f8cSWim Van Sebroeck { 590b7e04f8cSWim Van Sebroeck int ret; 591b7e04f8cSWim Van Sebroeck 59204bedfa5SAlan Cox if (type != 500 && type != 501) { 59327c766aaSJoe Perches pr_err("unknown card type '%d'\n", type); 59404bedfa5SAlan Cox return -ENODEV; 59504bedfa5SAlan Cox } 59604bedfa5SAlan Cox 5979f2d1f0dSAlan Cox /* Check that the heartbeat value is within it's range; 5989f2d1f0dSAlan Cox if not reset to the default */ 599b7e04f8cSWim Van Sebroeck if (wdt_set_heartbeat(heartbeat)) { 600b7e04f8cSWim Van Sebroeck wdt_set_heartbeat(WD_TIMO); 60127c766aaSJoe Perches pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n", 60227c766aaSJoe Perches WD_TIMO); 603b7e04f8cSWim Van Sebroeck } 604b7e04f8cSWim Van Sebroeck 605b7e04f8cSWim Van Sebroeck if (!request_region(io, 8, "wdt501p")) { 60627c766aaSJoe Perches pr_err("I/O address 0x%04x already in use\n", io); 607b7e04f8cSWim Van Sebroeck ret = -EBUSY; 608b7e04f8cSWim Van Sebroeck goto out; 609b7e04f8cSWim Van Sebroeck } 610b7e04f8cSWim Van Sebroeck 61186b59128SYong Zhang ret = request_irq(irq, wdt_interrupt, 0, "wdt501p", NULL); 612b7e04f8cSWim Van Sebroeck if (ret) { 61327c766aaSJoe Perches pr_err("IRQ %d is not free\n", irq); 614b7e04f8cSWim Van Sebroeck goto outreg; 615b7e04f8cSWim Van Sebroeck } 616b7e04f8cSWim Van Sebroeck 617b7e04f8cSWim Van Sebroeck ret = register_reboot_notifier(&wdt_notifier); 618b7e04f8cSWim Van Sebroeck if (ret) { 61927c766aaSJoe Perches pr_err("cannot register reboot notifier (err=%d)\n", ret); 620b7e04f8cSWim Van Sebroeck goto outirq; 621b7e04f8cSWim Van Sebroeck } 622b7e04f8cSWim Van Sebroeck 62304bedfa5SAlan Cox if (type == 501) { 624b7e04f8cSWim Van Sebroeck ret = misc_register(&temp_miscdev); 625b7e04f8cSWim Van Sebroeck if (ret) { 62627c766aaSJoe Perches pr_err("cannot register miscdev on minor=%d (err=%d)\n", 62727c766aaSJoe Perches TEMP_MINOR, ret); 628b7e04f8cSWim Van Sebroeck goto outrbt; 629b7e04f8cSWim Van Sebroeck } 63004bedfa5SAlan Cox } 631b7e04f8cSWim Van Sebroeck 632b7e04f8cSWim Van Sebroeck ret = misc_register(&wdt_miscdev); 633b7e04f8cSWim Van Sebroeck if (ret) { 63427c766aaSJoe Perches pr_err("cannot register miscdev on minor=%d (err=%d)\n", 635b7e04f8cSWim Van Sebroeck WATCHDOG_MINOR, ret); 636b7e04f8cSWim Van Sebroeck goto outmisc; 637b7e04f8cSWim Van Sebroeck } 638b7e04f8cSWim Van Sebroeck 63927c766aaSJoe Perches pr_info("WDT500/501-P driver 0.10 at 0x%04x (Interrupt %d). heartbeat=%d sec (nowayout=%d)\n", 640b7e04f8cSWim Van Sebroeck io, irq, heartbeat, nowayout); 64104bedfa5SAlan Cox if (type == 501) 64227c766aaSJoe Perches pr_info("Fan Tachometer is %s\n", 64327c766aaSJoe Perches tachometer ? "Enabled" : "Disabled"); 64404bedfa5SAlan Cox return 0; 645b7e04f8cSWim Van Sebroeck 646b7e04f8cSWim Van Sebroeck outmisc: 64704bedfa5SAlan Cox if (type == 501) 648b7e04f8cSWim Van Sebroeck misc_deregister(&temp_miscdev); 649b7e04f8cSWim Van Sebroeck outrbt: 650b7e04f8cSWim Van Sebroeck unregister_reboot_notifier(&wdt_notifier); 651b7e04f8cSWim Van Sebroeck outirq: 652b7e04f8cSWim Van Sebroeck free_irq(irq, NULL); 653b7e04f8cSWim Van Sebroeck outreg: 654b7e04f8cSWim Van Sebroeck release_region(io, 8); 65504bedfa5SAlan Cox out: 65604bedfa5SAlan Cox return ret; 657b7e04f8cSWim Van Sebroeck } 658b7e04f8cSWim Van Sebroeck 659b7e04f8cSWim Van Sebroeck module_init(wdt_init); 660b7e04f8cSWim Van Sebroeck module_exit(wdt_exit); 661b7e04f8cSWim Van Sebroeck 662b7e04f8cSWim Van Sebroeck MODULE_AUTHOR("Alan Cox"); 663b7e04f8cSWim Van Sebroeck MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)"); 664b7e04f8cSWim Van Sebroeck MODULE_LICENSE("GPL"); 665