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
20 * 20020222 Zwane Mwaikambo Added probing.
21 * 20020225 Zwane Mwaikambo Added ISAPNP support.
22 * 20020412 Rob Radez Broke out start/stop functions
23 * <rob@osinvestor.com> Return proper status instead of
25 * Add WDIOC_GETBOOTSTATUS and
26 * WDIOC_SETOPTIONS ioctls
27 * Fix CONFIG_WATCHDOG_NOWAYOUT
28 * 20020530 Joel Becker Add Matt Domsch's nowayout module
30 * 20030116 Adam Belay Updated to the latest pnp code
34 #include <linux/module.h>
35 #include <linux/moduleparam.h>
36 #include <linux/miscdevice.h>
37 #include <linux/watchdog.h>
38 #include <linux/ioport.h>
39 #include <linux/spinlock.h>
40 #include <linux/notifier.h>
41 #include <linux/reboot.h>
42 #include <linux/init.h>
43 #include <linux/pnp.h>
45 #include <linux/semaphore.h>
47 #include <linux/uaccess.h>
49 #define SC1200_MODULE_VER "build 20020303"
50 #define SC1200_MODULE_NAME "sc1200wdt"
51 #define PFX SC1200_MODULE_NAME ": "
53 #define MAX_TIMEOUT 255 /* 255 minutes */
54 #define PMIR (io) /* Power Management Index Register */
55 #define PMDR (io+1) /* Power Management Data Register */
57 /* Data Register indexes */
58 #define FER1 0x00 /* Function enable register 1 */
59 #define FER2 0x01 /* Function enable register 2 */
60 #define PMC1 0x02 /* Power Management Ctrl 1 */
61 #define PMC2 0x03 /* Power Management Ctrl 2 */
62 #define PMC3 0x04 /* Power Management Ctrl 3 */
63 #define WDTO 0x05 /* Watchdog timeout register */
64 #define WDCF 0x06 /* Watchdog config register */
65 #define WDST 0x07 /* Watchdog status register */
67 /* WDCF bitfields - which devices assert WDO */
68 #define KBC_IRQ 0x01 /* Keyboard Controller */
69 #define MSE_IRQ 0x02 /* Mouse */
70 #define UART1_IRQ 0x03 /* Serial0 */
71 #define UART2_IRQ 0x04 /* Serial1 */
72 /* 5 -7 are reserved */
74 static char banner
[] __initdata
= KERN_INFO PFX SC1200_MODULE_VER
;
75 static int timeout
= 1;
77 static int io_len
= 2; /* for non plug and play */
78 static unsigned long open_flag
;
79 static char expect_close
;
80 static DEFINE_SPINLOCK(sc1200wdt_lock
); /* io port access serialisation */
82 #if defined CONFIG_PNP
83 static int isapnp
= 1;
84 static struct pnp_dev
*wdt_dev
;
86 module_param(isapnp
, int, 0);
87 MODULE_PARM_DESC(isapnp
,
88 "When set to 0 driver ISA PnP support will be disabled");
91 module_param(io
, int, 0);
92 MODULE_PARM_DESC(io
, "io port");
93 module_param(timeout
, int, 0);
94 MODULE_PARM_DESC(timeout
, "range is 0-255 minutes, default is 1");
96 static int nowayout
= WATCHDOG_NOWAYOUT
;
97 module_param(nowayout
, int, 0);
98 MODULE_PARM_DESC(nowayout
,
99 "Watchdog cannot be stopped once started (default="
100 __MODULE_STRING(WATCHDOG_NOWAYOUT
) ")");
104 /* Read from Data Register */
105 static inline void __sc1200wdt_read_data(unsigned char index
,
112 static void sc1200wdt_read_data(unsigned char index
, unsigned char *data
)
114 spin_lock(&sc1200wdt_lock
);
115 __sc1200wdt_read_data(index
, data
);
116 spin_unlock(&sc1200wdt_lock
);
119 /* Write to Data Register */
120 static inline void __sc1200wdt_write_data(unsigned char index
,
127 static inline void sc1200wdt_write_data(unsigned char index
,
130 spin_lock(&sc1200wdt_lock
);
131 __sc1200wdt_write_data(index
, data
);
132 spin_unlock(&sc1200wdt_lock
);
136 static void sc1200wdt_start(void)
139 spin_lock(&sc1200wdt_lock
);
141 __sc1200wdt_read_data(WDCF
, ®
);
142 /* assert WDO when any of the following interrupts are triggered too */
143 reg
|= (KBC_IRQ
| MSE_IRQ
| UART1_IRQ
| UART2_IRQ
);
144 __sc1200wdt_write_data(WDCF
, reg
);
145 /* set the timeout and get the ball rolling */
146 __sc1200wdt_write_data(WDTO
, timeout
);
148 spin_unlock(&sc1200wdt_lock
);
151 static void sc1200wdt_stop(void)
153 sc1200wdt_write_data(WDTO
, 0);
156 /* This returns the status of the WDO signal, inactive high. */
157 static inline int sc1200wdt_status(void)
161 sc1200wdt_read_data(WDST
, &ret
);
162 /* If the bit is inactive, the watchdog is enabled, so return
163 * KEEPALIVEPING which is a bit of a kludge because there's nothing
164 * else for enabled/disabled status
166 return (ret
& 0x01) ? 0 : WDIOF_KEEPALIVEPING
;
169 static int sc1200wdt_open(struct inode
*inode
, struct file
*file
)
171 /* allow one at a time */
172 if (test_and_set_bit(0, &open_flag
))
175 if (timeout
> MAX_TIMEOUT
)
176 timeout
= MAX_TIMEOUT
;
179 printk(KERN_INFO PFX
"Watchdog enabled, timeout = %d min(s)", timeout
);
181 return nonseekable_open(inode
, file
);
185 static long sc1200wdt_ioctl(struct file
*file
, unsigned int cmd
,
189 void __user
*argp
= (void __user
*)arg
;
190 int __user
*p
= argp
;
191 static const struct watchdog_info ident
= {
192 .options
= WDIOF_KEEPALIVEPING
| WDIOF_SETTIMEOUT
|
194 .firmware_version
= 0,
195 .identity
= "PC87307/PC97307",
199 case WDIOC_GETSUPPORT
:
200 if (copy_to_user(argp
, &ident
, sizeof ident
))
204 case WDIOC_GETSTATUS
:
205 return put_user(sc1200wdt_status(), p
);
207 case WDIOC_GETBOOTSTATUS
:
208 return put_user(0, p
);
210 case WDIOC_SETOPTIONS
:
212 int options
, retval
= -EINVAL
;
214 if (get_user(options
, p
))
217 if (options
& WDIOS_DISABLECARD
) {
222 if (options
& WDIOS_ENABLECARD
) {
229 case WDIOC_KEEPALIVE
:
230 sc1200wdt_write_data(WDTO
, timeout
);
233 case WDIOC_SETTIMEOUT
:
234 if (get_user(new_timeout
, p
))
236 /* the API states this is given in secs */
238 if (new_timeout
< 0 || new_timeout
> MAX_TIMEOUT
)
240 timeout
= new_timeout
;
241 sc1200wdt_write_data(WDTO
, timeout
);
242 /* fall through and return the new timeout */
244 case WDIOC_GETTIMEOUT
:
245 return put_user(timeout
* 60, p
);
253 static int sc1200wdt_release(struct inode
*inode
, struct file
*file
)
255 if (expect_close
== 42) {
257 printk(KERN_INFO PFX
"Watchdog disabled\n");
259 sc1200wdt_write_data(WDTO
, timeout
);
261 "Unexpected close!, timeout = %d min(s)\n", timeout
);
263 clear_bit(0, &open_flag
);
270 static ssize_t
sc1200wdt_write(struct file
*file
, const char __user
*data
,
271 size_t len
, loff_t
*ppos
)
279 for (i
= 0; i
!= len
; i
++) {
282 if (get_user(c
, data
+ i
))
289 sc1200wdt_write_data(WDTO
, timeout
);
297 static int sc1200wdt_notify_sys(struct notifier_block
*this,
298 unsigned long code
, void *unused
)
300 if (code
== SYS_DOWN
|| code
== SYS_HALT
)
307 static struct notifier_block sc1200wdt_notifier
= {
308 .notifier_call
= sc1200wdt_notify_sys
,
311 static const struct file_operations sc1200wdt_fops
= {
312 .owner
= THIS_MODULE
,
314 .write
= sc1200wdt_write
,
315 .unlocked_ioctl
= sc1200wdt_ioctl
,
316 .open
= sc1200wdt_open
,
317 .release
= sc1200wdt_release
,
320 static struct miscdevice sc1200wdt_miscdev
= {
321 .minor
= WATCHDOG_MINOR
,
323 .fops
= &sc1200wdt_fops
,
327 static int __init
sc1200wdt_probe(void)
329 /* The probe works by reading the PMC3 register's default value of 0x0e
330 * there is one caveat, if the device disables the parallel port or any
331 * of the UARTs we won't be able to detect it.
332 * NB. This could be done with accuracy by reading the SID registers,
333 * but we don't have access to those io regions.
338 sc1200wdt_read_data(PMC3
, ®
);
339 reg
&= 0x0f; /* we don't want the UART busy bits */
340 return (reg
== 0x0e) ? 0 : -ENODEV
;
344 #if defined CONFIG_PNP
346 static struct pnp_device_id scl200wdt_pnp_devices
[] = {
347 /* National Semiconductor PC87307/PC97307 watchdog component */
348 {.id
= "NSC0800", .driver_data
= 0},
352 static int scl200wdt_pnp_probe(struct pnp_dev
*dev
,
353 const struct pnp_device_id
*dev_id
)
355 /* this driver only supports one card at a time */
356 if (wdt_dev
|| !isapnp
)
360 io
= pnp_port_start(wdt_dev
, 0);
361 io_len
= pnp_port_len(wdt_dev
, 0);
363 if (!request_region(io
, io_len
, SC1200_MODULE_NAME
)) {
364 printk(KERN_ERR PFX
"Unable to register IO port %#x\n", io
);
368 printk(KERN_INFO
"scl200wdt: PnP device found at io port %#x/%d\n",
373 static void scl200wdt_pnp_remove(struct pnp_dev
*dev
)
376 release_region(io
, io_len
);
381 static struct pnp_driver scl200wdt_pnp_driver
= {
383 .id_table
= scl200wdt_pnp_devices
,
384 .probe
= scl200wdt_pnp_probe
,
385 .remove
= scl200wdt_pnp_remove
,
388 #endif /* CONFIG_PNP */
391 static int __init
sc1200wdt_init(void)
395 printk("%s\n", banner
);
397 #if defined CONFIG_PNP
399 ret
= pnp_register_driver(&scl200wdt_pnp_driver
);
406 printk(KERN_ERR PFX
"io parameter must be specified\n");
411 #if defined CONFIG_PNP
412 /* now that the user has specified an IO port and we haven't detected
413 * any devices, disable pnp support */
415 pnp_unregister_driver(&scl200wdt_pnp_driver
);
418 if (!request_region(io
, io_len
, SC1200_MODULE_NAME
)) {
419 printk(KERN_ERR PFX
"Unable to register IO port %#x\n", io
);
424 ret
= sc1200wdt_probe();
428 ret
= register_reboot_notifier(&sc1200wdt_notifier
);
431 "Unable to register reboot notifier err = %d\n", ret
);
435 ret
= misc_register(&sc1200wdt_miscdev
);
438 "Unable to register miscdev on minor %d\n",
449 unregister_reboot_notifier(&sc1200wdt_notifier
);
452 release_region(io
, io_len
);
455 #if defined CONFIG_PNP
457 pnp_unregister_driver(&scl200wdt_pnp_driver
);
463 static void __exit
sc1200wdt_exit(void)
465 misc_deregister(&sc1200wdt_miscdev
);
466 unregister_reboot_notifier(&sc1200wdt_notifier
);
468 #if defined CONFIG_PNP
470 pnp_unregister_driver(&scl200wdt_pnp_driver
);
473 release_region(io
, io_len
);
476 module_init(sc1200wdt_init
);
477 module_exit(sc1200wdt_exit
);
479 MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
480 MODULE_DESCRIPTION("Driver for National Semiconductor PC87307/PC97307 watchdog component");
481 MODULE_LICENSE("GPL");
482 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);