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/module.h>
31 #include <linux/moduleparam.h>
32 #include <linux/miscdevice.h>
33 #include <linux/watchdog.h>
34 #include <linux/ioport.h>
35 #include <linux/spinlock.h>
36 #include <linux/notifier.h>
37 #include <linux/reboot.h>
38 #include <linux/init.h>
39 #include <linux/pnp.h>
42 #include <asm/semaphore.h>
44 #include <asm/uaccess.h>
46 #define SC1200_MODULE_VER "build 20020303"
47 #define SC1200_MODULE_NAME "sc1200wdt"
48 #define PFX SC1200_MODULE_NAME ": "
50 #define MAX_TIMEOUT 255 /* 255 minutes */
51 #define PMIR (io) /* Power Management Index Register */
52 #define PMDR (io+1) /* Power Management Data Register */
54 /* Data Register indexes */
55 #define FER1 0x00 /* Function enable register 1 */
56 #define FER2 0x01 /* Function enable register 2 */
57 #define PMC1 0x02 /* Power Management Ctrl 1 */
58 #define PMC2 0x03 /* Power Management Ctrl 2 */
59 #define PMC3 0x04 /* Power Management Ctrl 3 */
60 #define WDTO 0x05 /* Watchdog timeout register */
61 #define WDCF 0x06 /* Watchdog config register */
62 #define WDST 0x07 /* Watchdog status register */
64 /* WDCF bitfields - which devices assert WDO */
65 #define KBC_IRQ 0x01 /* Keyboard Controller */
66 #define MSE_IRQ 0x02 /* Mouse */
67 #define UART1_IRQ 0x03 /* Serial0 */
68 #define UART2_IRQ 0x04 /* Serial1 */
69 /* 5 -7 are reserved */
71 static char banner[] __initdata = KERN_INFO PFX SC1200_MODULE_VER;
72 static int timeout = 1;
74 static int io_len = 2; /* for non plug and play */
75 static struct semaphore open_sem;
76 static char expect_close;
77 static spinlock_t sc1200wdt_lock; /* io port access serialisation */
79 #if defined CONFIG_PNP
80 static int isapnp = 1;
81 static struct pnp_dev *wdt_dev;
83 module_param(isapnp, int, 0);
84 MODULE_PARM_DESC(isapnp, "When set to 0 driver ISA PnP support will be disabled");
87 module_param(io, int, 0);
88 MODULE_PARM_DESC(io, "io port");
89 module_param(timeout, int, 0);
90 MODULE_PARM_DESC(timeout, "range is 0-255 minutes, default is 1");
92 static int nowayout = WATCHDOG_NOWAYOUT;
93 module_param(nowayout, int, 0);
94 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
98 /* Read from Data Register */
99 static inline void sc1200wdt_read_data(unsigned char index, unsigned char *data)
101 spin_lock(&sc1200wdt_lock);
104 spin_unlock(&sc1200wdt_lock);
108 /* Write to Data Register */
109 static inline void sc1200wdt_write_data(unsigned char index, unsigned char data)
111 spin_lock(&sc1200wdt_lock);
114 spin_unlock(&sc1200wdt_lock);
118 static void sc1200wdt_start(void)
122 sc1200wdt_read_data(WDCF, ®);
123 /* assert WDO when any of the following interrupts are triggered too */
124 reg |= (KBC_IRQ | MSE_IRQ | UART1_IRQ | UART2_IRQ);
125 sc1200wdt_write_data(WDCF, reg);
126 /* set the timeout and get the ball rolling */
127 sc1200wdt_write_data(WDTO, timeout);
131 static void sc1200wdt_stop(void)
133 sc1200wdt_write_data(WDTO, 0);
137 /* This returns the status of the WDO signal, inactive high. */
138 static inline int sc1200wdt_status(void)
142 sc1200wdt_read_data(WDST, &ret);
143 /* If the bit is inactive, the watchdog is enabled, so return
144 * KEEPALIVEPING which is a bit of a kludge because there's nothing
145 * else for enabled/disabled status
147 return (ret & 0x01) ? 0 : WDIOF_KEEPALIVEPING; /* bits 1 - 7 are undefined */
151 static int sc1200wdt_open(struct inode *inode, struct file *file)
153 nonseekable_open(inode, file);
155 /* allow one at a time */
156 if (down_trylock(&open_sem))
159 if (timeout > MAX_TIMEOUT)
160 timeout = MAX_TIMEOUT;
163 printk(KERN_INFO PFX "Watchdog enabled, timeout = %d min(s)", timeout);
169 static int sc1200wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
172 void __user *argp = (void __user *)arg;
173 int __user *p = argp;
174 static struct watchdog_info ident = {
175 .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
176 .firmware_version = 0,
177 .identity = "PC87307/PC97307",
184 case WDIOC_GETSUPPORT:
185 if (copy_to_user(argp, &ident, sizeof ident))
189 case WDIOC_GETSTATUS:
190 return put_user(sc1200wdt_status(), p);
192 case WDIOC_GETBOOTSTATUS:
193 return put_user(0, p);
195 case WDIOC_KEEPALIVE:
196 sc1200wdt_write_data(WDTO, timeout);
199 case WDIOC_SETTIMEOUT:
200 if (get_user(new_timeout, p))
203 /* the API states this is given in secs */
205 if (new_timeout < 0 || new_timeout > MAX_TIMEOUT)
208 timeout = new_timeout;
209 sc1200wdt_write_data(WDTO, timeout);
210 /* fall through and return the new timeout */
212 case WDIOC_GETTIMEOUT:
213 return put_user(timeout * 60, p);
215 case WDIOC_SETOPTIONS:
217 int options, retval = -EINVAL;
219 if (get_user(options, p))
222 if (options & WDIOS_DISABLECARD) {
227 if (options & WDIOS_ENABLECARD) {
238 static int sc1200wdt_release(struct inode *inode, struct file *file)
240 if (expect_close == 42) {
242 printk(KERN_INFO PFX "Watchdog disabled\n");
244 sc1200wdt_write_data(WDTO, timeout);
245 printk(KERN_CRIT PFX "Unexpected close!, timeout = %d min(s)\n", timeout);
254 static ssize_t sc1200wdt_write(struct file *file, const char __user *data, size_t len, loff_t *ppos)
262 for (i = 0; i != len; i++) {
265 if (get_user(c, data+i))
272 sc1200wdt_write_data(WDTO, timeout);
280 static int sc1200wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused)
282 if (code == SYS_DOWN || code == SYS_HALT)
289 static struct notifier_block sc1200wdt_notifier =
291 .notifier_call = sc1200wdt_notify_sys,
294 static const struct file_operations sc1200wdt_fops =
296 .owner = THIS_MODULE,
298 .write = sc1200wdt_write,
299 .ioctl = sc1200wdt_ioctl,
300 .open = sc1200wdt_open,
301 .release = sc1200wdt_release,
304 static struct miscdevice sc1200wdt_miscdev =
306 .minor = WATCHDOG_MINOR,
308 .fops = &sc1200wdt_fops,
312 static int __init sc1200wdt_probe(void)
314 /* The probe works by reading the PMC3 register's default value of 0x0e
315 * there is one caveat, if the device disables the parallel port or any
316 * of the UARTs we won't be able to detect it.
317 * Nb. This could be done with accuracy by reading the SID registers, but
318 * we don't have access to those io regions.
323 sc1200wdt_read_data(PMC3, ®);
324 reg &= 0x0f; /* we don't want the UART busy bits */
325 return (reg == 0x0e) ? 0 : -ENODEV;
329 #if defined CONFIG_PNP
331 static struct pnp_device_id scl200wdt_pnp_devices[] = {
332 /* National Semiconductor PC87307/PC97307 watchdog component */
333 {.id = "NSC0800", .driver_data = 0},
337 static int scl200wdt_pnp_probe(struct pnp_dev * dev, const struct pnp_device_id *dev_id)
339 /* this driver only supports one card at a time */
340 if (wdt_dev || !isapnp)
344 io = pnp_port_start(wdt_dev, 0);
345 io_len = pnp_port_len(wdt_dev, 0);
347 if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
348 printk(KERN_ERR PFX "Unable to register IO port %#x\n", io);
352 printk(KERN_INFO "scl200wdt: PnP device found at io port %#x/%d\n", io, io_len);
356 static void scl200wdt_pnp_remove(struct pnp_dev * dev)
359 release_region(io, io_len);
364 static struct pnp_driver scl200wdt_pnp_driver = {
366 .id_table = scl200wdt_pnp_devices,
367 .probe = scl200wdt_pnp_probe,
368 .remove = scl200wdt_pnp_remove,
371 #endif /* CONFIG_PNP */
374 static int __init sc1200wdt_init(void)
378 printk("%s\n", banner);
380 spin_lock_init(&sc1200wdt_lock);
381 sema_init(&open_sem, 1);
383 #if defined CONFIG_PNP
385 ret = pnp_register_driver(&scl200wdt_pnp_driver);
392 printk(KERN_ERR PFX "io parameter must be specified\n");
397 #if defined CONFIG_PNP
398 /* now that the user has specified an IO port and we haven't detected
399 * any devices, disable pnp support */
401 pnp_unregister_driver(&scl200wdt_pnp_driver);
404 if (!request_region(io, io_len, SC1200_MODULE_NAME)) {
405 printk(KERN_ERR PFX "Unable to register IO port %#x\n", io);
410 ret = sc1200wdt_probe();
414 ret = register_reboot_notifier(&sc1200wdt_notifier);
416 printk(KERN_ERR PFX "Unable to register reboot notifier err = %d\n", ret);
420 ret = misc_register(&sc1200wdt_miscdev);
422 printk(KERN_ERR PFX "Unable to register miscdev on minor %d\n", WATCHDOG_MINOR);
432 unregister_reboot_notifier(&sc1200wdt_notifier);
435 release_region(io, io_len);
438 #if defined CONFIG_PNP
440 pnp_unregister_driver(&scl200wdt_pnp_driver);
446 static void __exit sc1200wdt_exit(void)
448 misc_deregister(&sc1200wdt_miscdev);
449 unregister_reboot_notifier(&sc1200wdt_notifier);
451 #if defined CONFIG_PNP
453 pnp_unregister_driver(&scl200wdt_pnp_driver);
456 release_region(io, io_len);
459 module_init(sc1200wdt_init);
460 module_exit(sc1200wdt_exit);
462 MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
463 MODULE_DESCRIPTION("Driver for National Semiconductor PC87307/PC97307 watchdog component");
464 MODULE_LICENSE("GPL");
465 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);