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>
42 #include <linux/pci.h>
44 #include <asm/semaphore.h>
46 #include <asm/uaccess.h>
48 #define SC1200_MODULE_VER "build 20020303"
49 #define SC1200_MODULE_NAME "sc1200wdt"
50 #define PFX SC1200_MODULE_NAME ": "
52 #define MAX_TIMEOUT 255 /* 255 minutes */
53 #define PMIR (io) /* Power Management Index Register */
54 #define PMDR (io+1) /* Power Management Data Register */
56 /* Data Register indexes */
57 #define FER1 0x00 /* Function enable register 1 */
58 #define FER2 0x01 /* Function enable register 2 */
59 #define PMC1 0x02 /* Power Management Ctrl 1 */
60 #define PMC2 0x03 /* Power Management Ctrl 2 */
61 #define PMC3 0x04 /* Power Management Ctrl 3 */
62 #define WDTO 0x05 /* Watchdog timeout register */
63 #define WDCF 0x06 /* Watchdog config register */
64 #define WDST 0x07 /* Watchdog status register */
66 /* WDCF bitfields - which devices assert WDO */
67 #define KBC_IRQ 0x01 /* Keyboard Controller */
68 #define MSE_IRQ 0x02 /* Mouse */
69 #define UART1_IRQ 0x03 /* Serial0 */
70 #define UART2_IRQ 0x04 /* Serial1 */
71 /* 5 -7 are reserved */
73 static char banner
[] __initdata
= KERN_INFO PFX SC1200_MODULE_VER
;
74 static int timeout
= 1;
76 static int io_len
= 2; /* for non plug and play */
77 static struct semaphore open_sem
;
78 static char expect_close
;
79 static spinlock_t sc1200wdt_lock
; /* io port access serialisation */
81 #if defined CONFIG_PNP
82 static int isapnp
= 1;
83 static struct pnp_dev
*wdt_dev
;
85 module_param(isapnp
, int, 0);
86 MODULE_PARM_DESC(isapnp
, "When set to 0 driver ISA PnP support will be disabled");
89 module_param(io
, int, 0);
90 MODULE_PARM_DESC(io
, "io port");
91 module_param(timeout
, int, 0);
92 MODULE_PARM_DESC(timeout
, "range is 0-255 minutes, default is 1");
94 static int nowayout
= WATCHDOG_NOWAYOUT
;
95 module_param(nowayout
, int, 0);
96 MODULE_PARM_DESC(nowayout
, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
100 /* Read from Data Register */
101 static inline void sc1200wdt_read_data(unsigned char index
, unsigned char *data
)
103 spin_lock(&sc1200wdt_lock
);
106 spin_unlock(&sc1200wdt_lock
);
110 /* Write to Data Register */
111 static inline void sc1200wdt_write_data(unsigned char index
, unsigned char data
)
113 spin_lock(&sc1200wdt_lock
);
116 spin_unlock(&sc1200wdt_lock
);
120 static void sc1200wdt_start(void)
124 sc1200wdt_read_data(WDCF
, ®
);
125 /* assert WDO when any of the following interrupts are triggered too */
126 reg
|= (KBC_IRQ
| MSE_IRQ
| UART1_IRQ
| UART2_IRQ
);
127 sc1200wdt_write_data(WDCF
, reg
);
128 /* set the timeout and get the ball rolling */
129 sc1200wdt_write_data(WDTO
, timeout
);
133 static void sc1200wdt_stop(void)
135 sc1200wdt_write_data(WDTO
, 0);
139 /* This returns the status of the WDO signal, inactive high. */
140 static inline int sc1200wdt_status(void)
144 sc1200wdt_read_data(WDST
, &ret
);
145 /* If the bit is inactive, the watchdog is enabled, so return
146 * KEEPALIVEPING which is a bit of a kludge because there's nothing
147 * else for enabled/disabled status
149 return (ret
& 0x01) ? 0 : WDIOF_KEEPALIVEPING
; /* bits 1 - 7 are undefined */
153 static int sc1200wdt_open(struct inode
*inode
, struct file
*file
)
155 nonseekable_open(inode
, file
);
157 /* allow one at a time */
158 if (down_trylock(&open_sem
))
161 if (timeout
> MAX_TIMEOUT
)
162 timeout
= MAX_TIMEOUT
;
165 printk(KERN_INFO PFX
"Watchdog enabled, timeout = %d min(s)", timeout
);
171 static int sc1200wdt_ioctl(struct inode
*inode
, struct file
*file
, unsigned int cmd
, unsigned long arg
)
174 void __user
*argp
= (void __user
*)arg
;
175 int __user
*p
= argp
;
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(argp
, &ident
, sizeof ident
))
191 case WDIOC_GETSTATUS
:
192 return put_user(sc1200wdt_status(), p
);
194 case WDIOC_GETBOOTSTATUS
:
195 return put_user(0, p
);
197 case WDIOC_KEEPALIVE
:
198 sc1200wdt_write_data(WDTO
, timeout
);
201 case WDIOC_SETTIMEOUT
:
202 if (get_user(new_timeout
, p
))
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, p
);
217 case WDIOC_SETOPTIONS
:
219 int options
, retval
= -EINVAL
;
221 if (get_user(options
, p
))
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 __user
*data
, size_t len
, loff_t
*ppos
)
264 for (i
= 0; i
!= len
; i
++) {
267 if (get_user(c
, data
+i
))
274 sc1200wdt_write_data(WDTO
, timeout
);
282 static int sc1200wdt_notify_sys(struct notifier_block
*this, unsigned long code
, void *unused
)
284 if (code
== SYS_DOWN
|| code
== SYS_HALT
)
291 static struct notifier_block sc1200wdt_notifier
=
293 .notifier_call
= sc1200wdt_notify_sys
,
296 static struct file_operations sc1200wdt_fops
=
298 .owner
= THIS_MODULE
,
300 .write
= sc1200wdt_write
,
301 .ioctl
= sc1200wdt_ioctl
,
302 .open
= sc1200wdt_open
,
303 .release
= sc1200wdt_release
,
306 static struct miscdevice sc1200wdt_miscdev
=
308 .minor
= WATCHDOG_MINOR
,
310 .fops
= &sc1200wdt_fops
,
314 static int __init
sc1200wdt_probe(void)
316 /* The probe works by reading the PMC3 register's default value of 0x0e
317 * there is one caveat, if the device disables the parallel port or any
318 * of the UARTs we won't be able to detect it.
319 * Nb. This could be done with accuracy by reading the SID registers, but
320 * we don't have access to those io regions.
325 sc1200wdt_read_data(PMC3
, ®
);
326 reg
&= 0x0f; /* we don't want the UART busy bits */
327 return (reg
== 0x0e) ? 0 : -ENODEV
;
331 #if defined CONFIG_PNP
333 static struct pnp_device_id scl200wdt_pnp_devices
[] = {
334 /* National Semiconductor PC87307/PC97307 watchdog component */
335 {.id
= "NSC0800", .driver_data
= 0},
339 static int scl200wdt_pnp_probe(struct pnp_dev
* dev
, const struct pnp_device_id
*dev_id
)
341 /* this driver only supports one card at a time */
342 if (wdt_dev
|| !isapnp
)
346 io
= pnp_port_start(wdt_dev
, 0);
347 io_len
= pnp_port_len(wdt_dev
, 0);
349 if (!request_region(io
, io_len
, SC1200_MODULE_NAME
)) {
350 printk(KERN_ERR PFX
"Unable to register IO port %#x\n", io
);
354 printk(KERN_INFO
"scl200wdt: PnP device found at io port %#x/%d\n", io
, io_len
);
358 static void scl200wdt_pnp_remove(struct pnp_dev
* dev
)
361 release_region(io
, io_len
);
366 static struct pnp_driver scl200wdt_pnp_driver
= {
368 .id_table
= scl200wdt_pnp_devices
,
369 .probe
= scl200wdt_pnp_probe
,
370 .remove
= scl200wdt_pnp_remove
,
373 #endif /* CONFIG_PNP */
376 static int __init
sc1200wdt_init(void)
382 spin_lock_init(&sc1200wdt_lock
);
383 sema_init(&open_sem
, 1);
385 #if defined CONFIG_PNP
387 ret
= pnp_register_driver(&scl200wdt_pnp_driver
);
394 printk(KERN_ERR PFX
"io parameter must be specified\n");
399 #if defined CONFIG_PNP
400 /* now that the user has specified an IO port and we haven't detected
401 * any devices, disable pnp support */
403 pnp_unregister_driver(&scl200wdt_pnp_driver
);
406 if (!request_region(io
, io_len
, SC1200_MODULE_NAME
)) {
407 printk(KERN_ERR PFX
"Unable to register IO port %#x\n", io
);
412 ret
= sc1200wdt_probe();
416 ret
= register_reboot_notifier(&sc1200wdt_notifier
);
418 printk(KERN_ERR PFX
"Unable to register reboot notifier err = %d\n", ret
);
422 ret
= misc_register(&sc1200wdt_miscdev
);
424 printk(KERN_ERR PFX
"Unable to register miscdev on minor %d\n", WATCHDOG_MINOR
);
434 unregister_reboot_notifier(&sc1200wdt_notifier
);
437 release_region(io
, io_len
);
443 static void __exit
sc1200wdt_exit(void)
445 misc_deregister(&sc1200wdt_miscdev
);
446 unregister_reboot_notifier(&sc1200wdt_notifier
);
448 #if defined CONFIG_PNP
450 pnp_unregister_driver(&scl200wdt_pnp_driver
);
453 release_region(io
, io_len
);
456 module_init(sc1200wdt_init
);
457 module_exit(sc1200wdt_exit
);
459 MODULE_AUTHOR("Zwane Mwaikambo <zwane@commfireservices.com>");
460 MODULE_DESCRIPTION("Driver for National Semiconductor PC87307/PC97307 watchdog component");
461 MODULE_LICENSE("GPL");
462 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);