2 * National Semiconductor PC87307/PC97307 (ala SC1200) WDT driver
3 * (c) Copyright 2002 Zwane Mwaikambo <zwane@commfireservices.com>,
5 * Based on wdt.c and wdt977.c by Alan Cox and Woody Suwalski respectively.
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
12 * The author(s) of this software shall not be held liable for damages
13 * of any nature resulting due to the use of this software. This
14 * software is provided AS-IS with no warranties.
17 * 20020220 Zwane Mwaikambo Code based on datasheet, no hardware.
18 * 20020221 Zwane Mwaikambo Cleanups as suggested by Jeff Garzik and Alan Cox.
19 * 20020222 Zwane Mwaikambo Added probing.
20 * 20020225 Zwane Mwaikambo Added ISAPNP support.
21 * 20020412 Rob Radez Broke out start/stop functions
22 * <rob@osinvestor.com> Return proper status instead of temperature warning
23 * Add WDIOC_GETBOOTSTATUS and WDIOC_SETOPTIONS ioctls
24 * Fix CONFIG_WATCHDOG_NOWAYOUT
25 * 20020530 Joel Becker Add Matt Domsch's nowayout module option
26 * 20030116 Adam Belay Updated to the latest pnp code
30 #include <linux/config.h>
31 #include <linux/module.h>
32 #include <linux/moduleparam.h>
33 #include <linux/miscdevice.h>
34 #include <linux/watchdog.h>
35 #include <linux/ioport.h>
36 #include <linux/spinlock.h>
37 #include <linux/notifier.h>
38 #include <linux/reboot.h>
39 #include <linux/init.h>
40 #include <linux/pnp.h>
41 #include <linux/pci.h>
43 #include <asm/semaphore.h>
45 #include <asm/uaccess.h>
47 #define SC1200_MODULE_VER "build 20020303"
48 #define SC1200_MODULE_NAME "sc1200wdt"
49 #define PFX SC1200_MODULE_NAME ": "
51 #define MAX_TIMEOUT 255 /* 255 minutes */
52 #define PMIR (io) /* Power Management Index Register */
53 #define PMDR (io+1) /* Power Management Data Register */
55 /* Data Register indexes */
56 #define FER1 0x00 /* Function enable register 1 */
57 #define FER2 0x01 /* Function enable register 2 */
58 #define PMC1 0x02 /* Power Management Ctrl 1 */
59 #define PMC2 0x03 /* Power Management Ctrl 2 */
60 #define PMC3 0x04 /* Power Management Ctrl 3 */
61 #define WDTO 0x05 /* Watchdog timeout register */
62 #define WDCF 0x06 /* Watchdog config register */
63 #define WDST 0x07 /* Watchdog status register */
65 /* WDCF bitfields - which devices assert WDO */
66 #define KBC_IRQ 0x01 /* Keyboard Controller */
67 #define MSE_IRQ 0x02 /* Mouse */
68 #define UART1_IRQ 0x03 /* Serial0 */
69 #define UART2_IRQ 0x04 /* Serial1 */
70 /* 5 -7 are reserved */
72 static char banner[] __initdata = KERN_INFO PFX SC1200_MODULE_VER;
73 static int timeout = 1;
75 static int io_len = 2; /* for non plug and play */
76 struct semaphore open_sem;
77 static char expect_close;
78 spinlock_t sc1200wdt_lock; /* io port access serialisation */
80 #if defined CONFIG_PNP
81 static int isapnp = 1;
82 static struct pnp_dev *wdt_dev;
84 module_param(isapnp, int, 0);
85 MODULE_PARM_DESC(isapnp, "When set to 0 driver ISA PnP support will be disabled");
88 module_param(io, int, 0);
89 MODULE_PARM_DESC(io, "io port");
90 module_param(timeout, int, 0);
91 MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");
93 #ifdef CONFIG_WATCHDOG_NOWAYOUT
94 static int nowayout = 1;
96 static int nowayout = 0;
99 module_param(nowayout, int, 0);
100 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
104 /* Read from Data Register */
105 static inline void sc1200wdt_read_data(unsigned char index, unsigned char *data)
107 spin_lock(&sc1200wdt_lock);
110 spin_unlock(&sc1200wdt_lock);
114 /* Write to Data Register */
115 static inline void sc1200wdt_write_data(unsigned char index, unsigned char data)
117 spin_lock(&sc1200wdt_lock);
120 spin_unlock(&sc1200wdt_lock);
124 static void sc1200wdt_start(void)
128 sc1200wdt_read_data(WDCF, ®);
129 /* assert WDO when any of the following interrupts are triggered too */
130 reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ);
131 sc1200wdt_write_data(WDCF, reg);
132 /* set the timeout and get the ball rolling */
133 sc1200wdt_write_data(WDTO, timeout);
137 static void sc1200wdt_stop(void)
139 sc1200wdt_write_data(WDTO, 0);
143 /* This returns the status of the WDO signal, inactive high. */
144 static inline int sc1200wdt_status(void)
148 sc1200wdt_read_data(WDST, &ret);
149 /* If the bit is inactive, the watchdog is enabled, so return
150 * KEEPALIVEPING which is a bit of a kludge because there's nothing
151 * else for enabled/disabled status
153 return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING; /* bits 1 - 7 are undefined */
157 static int sc1200wdt_open(struct inode *inode, struct file *file)
159 /* allow one at a time */
160 if (down_trylock(&open_sem))
163 if (timeout > MAX_TIMEOUT)
164 timeout = MAX_TIMEOUT;
167 printk(KERN_INFO PFX "Watchdog enabled, timeout = %d min(s)", timeout);
173 static int sc1200wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
176 static struct watchdog_info ident = {
177 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
178 .firmware_version = 0,
179 .identity = "PC87307/PC97307",
184 return -ENOIOCTLCMD; /* Keep Pavel Machek amused ;) */
186 case WDIOC_GETSUPPORT:
187 if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof ident))
191 case WDIOC_GETSTATUS:
192 return put_user(sc1200wdt_status(), (int *)arg);
194 case WDIOC_GETBOOTSTATUS:
195 return put_user(0, (int *)arg);
197 case WDIOC_KEEPALIVE:
198 sc1200wdt_write_data(WDTO, timeout);
201 case WDIOC_SETTIMEOUT:
202 if (get_user(new_timeout, (int *)arg))
205 /* the API states this is given in secs */
207 if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
210 timeout = new_timeout;
211 sc1200wdt_write_data(WDTO, timeout);
212 /* fall through and return the new timeout */
214 case WDIOC_GETTIMEOUT:
215 return put_user(timeout * 60, (int *)arg);
217 case WDIOC_SETOPTIONS:
219 int options, retval = -EINVAL;
221 if (get_user(options, (int *)arg))
224 if (options & WDIOS_DISABLECARD) {
229 if (options & WDIOS_ENABLECARD) {
240 static int sc1200wdt_release(struct inode *inode, struct file *file)
242 if (expect_close == 42) {
244 printk(KERN_INFO PFX "Watchdog disabled\n");
246 sc1200wdt_write_data(WDTO, timeout);
247 printk(KERN_CRIT PFX "Unexpected close!, timeout = %d min(s)\n", timeout);
256 static ssize_t sc1200wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
258 if (ppos != &file->f_pos)
267 for (i = 0; i != len; i++) {
270 if (get_user(c, data+i))
277 sc1200wdt_write_data(WDTO, timeout);
285 static int sc1200wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
287 if (code == SYS_DOWN || code == SYS_HALT)
294 static struct notifier_block sc1200wdt_notifier =
296 .notifier_call = sc1200wdt_notify_sys,
299 static struct file_operations sc1200wdt_fops =
301 .owner = THIS_MODULE,
302 .write = sc1200wdt_write,
303 .ioctl = sc1200wdt_ioctl,
304 .open = sc1200wdt_open,
305 .release = sc1200wdt_release,
308 static struct miscdevice sc1200wdt_miscdev =
310 .minor = WATCHDOG_MINOR,
312 .fops = &sc1200wdt_fops,
316 static int __init sc1200wdt_probe(void)
318 /* The probe works by reading the PMC3 register's default value of 0x0e
319 * there is one caveat, if the device disables the parallel port or any
320 * of the UARTs we won't be able to detect it.
321 * Nb. This could be done with accuracy by reading the SID registers, but
322 * we don't have access to those io regions.
327 sc1200wdt_read_data(PMC3, ®);
328 reg &= 0x0f; /* we don't want the UART busy bits */
329 return (reg == 0x0e) ? 0 : -ENODEV;
333 #if defined CONFIG_PNP
335 struct pnp_device_id scl200wdt_pnp_devices[] = {
336 /* National Semiconductor PC87307/PC97307 watchdog component */
337 {.id = "NSC0800", .driver_data = 0},
341 static int scl200wdt_pnp_probe(struct pnp_dev * dev, const struct pnp_device_id *dev_id)
343 /* this driver only supports one card at a time */
344 if (wdt_dev || !isapnp)
348 io = pnp_port_start(wdt_dev, 0);
349 io_len = pnp_port_len(wdt_dev, 0);
351 if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
352 printk(KERN_ERR PFX "Unable to register IO port %#x\n", io);
356 printk(KERN_INFO "scl200wdt: PnP device found at io port %#x/%d\n", io, io_len);
360 static void scl200wdt_pnp_remove(struct pnp_dev * dev)
363 release_region(io, io_len);
368 static struct pnp_driver scl200wdt_pnp_driver = {
370 .id_table = scl200wdt_pnp_devices,
371 .probe = scl200wdt_pnp_probe,
372 .remove = scl200wdt_pnp_remove,
375 #endif /* CONFIG_PNP */
378 static int __init sc1200wdt_init(void)
384 spin_lock_init(&sc1200wdt_lock);
385 sema_init(&open_sem, 1);
387 #if defined CONFIG_PNP
389 ret = pnp_register_driver(&scl200wdt_pnp_driver);
396 printk(KERN_ERR PFX "io parameter must be specified\n");
401 #if defined CONFIG_PNP
402 /* now that the user has specified an IO port and we haven't detected
403 * any devices, disable pnp support */
405 pnp_unregister_driver(&scl200wdt_pnp_driver);
408 if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
409 printk(KERN_ERR PFX "Unable to register IO port %#x\n", io);
414 ret = sc1200wdt_probe();
418 ret = register_reboot_notifier(&sc1200wdt_notifier);
420 printk(KERN_ERR PFX "Unable to register reboot notifier err = %d\n", ret);
424 ret = misc_register(&sc1200wdt_miscdev);
426 printk(KERN_ERR PFX "Unable to register miscdev on minor %d\n", WATCHDOG_MINOR);
436 unregister_reboot_notifier(&sc1200wdt_notifier);
439 release_region(io, io_len);
445 static void __exit sc1200wdt_exit(void)
447 misc_deregister(&sc1200wdt_miscdev);
448 unregister_reboot_notifier(&sc1200wdt_notifier);
450 #if defined CONFIG_PNP
452 pnp_unregister_driver(&scl200wdt_pnp_driver);
455 release_region(io, io_len);
458 module_init(sc1200wdt_init);
459 module_exit(sc1200wdt_exit);
461 MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
462 MODULE_DESCRIPTION("Driver for National Semiconductor PC87307/PC97307 watchdog component");
463 MODULE_LICENSE("GPL");
464 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);