2 * sch311x_wdt.c - Driver for the SCH311x Super-I/O chips
5 * (c) Copyright 2008 Wim Van Sebroeck <wim@iguana.be>.
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 * Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
13 * provide warranty for any of this software. This material is
14 * provided "AS-IS" and at no charge.
18 * Includes, defines, variables, module parameters, ...
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 #include <linux/module.h> /* For module specific items */
25 #include <linux/moduleparam.h> /* For new moduleparam's */
26 #include <linux/types.h> /* For standard types (like size_t) */
27 #include <linux/errno.h> /* For the -ENODEV/... values */
28 #include <linux/kernel.h> /* For printk/... */
29 #include <linux/miscdevice.h> /* For MODULE_ALIAS_MISCDEV
31 #include <linux/watchdog.h> /* For the watchdog specific items */
32 #include <linux/init.h> /* For __init/__exit/... */
33 #include <linux/fs.h> /* For file operations */
34 #include <linux/platform_device.h> /* For platform_driver framework */
35 #include <linux/ioport.h> /* For io-port access */
36 #include <linux/spinlock.h> /* For spin_lock/spin_unlock/... */
37 #include <linux/uaccess.h> /* For copy_to_user/put_user/... */
38 #include <linux/io.h> /* For inb/outb/... */
40 /* Module and version information */
41 #define DRV_NAME "sch311x_wdt"
43 /* Runtime registers */
45 #define WDT_TIME_OUT 0x65
50 /* internal variables */
51 static unsigned long sch311x_wdt_is_open;
52 static char sch311x_wdt_expect_close;
53 static struct platform_device *sch311x_wdt_pdev;
55 static int sch311x_ioports[] = { 0x2e, 0x4e, 0x162e, 0x164e, 0x00 };
57 static struct { /* The devices private data */
58 /* the Runtime Register base address */
59 unsigned short runtime_reg;
60 /* The card's boot status */
62 /* the lock for io operations */
66 /* Module load parameters */
67 static unsigned short force_id;
68 module_param(force_id, ushort, 0);
69 MODULE_PARM_DESC(force_id, "Override the detected device ID");
71 #define WATCHDOG_TIMEOUT 60 /* 60 sec default timeout */
72 static int timeout = WATCHDOG_TIMEOUT; /* in seconds */
73 module_param(timeout, int, 0);
74 MODULE_PARM_DESC(timeout,
75 "Watchdog timeout in seconds. 1<= timeout <=15300, default="
76 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
78 static bool nowayout = WATCHDOG_NOWAYOUT;
79 module_param(nowayout, bool, 0);
80 MODULE_PARM_DESC(nowayout,
81 "Watchdog cannot be stopped once started (default="
82 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
88 static inline void sch311x_sio_enter(int sio_config_port)
90 outb(0x55, sio_config_port);
93 static inline void sch311x_sio_exit(int sio_config_port)
95 outb(0xaa, sio_config_port);
98 static inline int sch311x_sio_inb(int sio_config_port, int reg)
100 outb(reg, sio_config_port);
101 return inb(sio_config_port + 1);
104 static inline void sch311x_sio_outb(int sio_config_port, int reg, int val)
106 outb(reg, sio_config_port);
107 outb(val, sio_config_port + 1);
111 * Watchdog Operations
114 static void sch311x_wdt_set_timeout(int t)
116 unsigned char timeout_unit = 0x80;
118 /* When new timeout is bigger then 255 seconds, we will use minutes */
124 /* -- Watchdog Timeout --
126 * Bit 7 WDT Time-out Value Units Select
127 * (0 = Minutes, 1 = Seconds)
129 outb(timeout_unit, sch311x_wdt_data.runtime_reg + WDT_TIME_OUT);
131 /* -- Watchdog Timer Time-out Value --
132 * Bit 0-7 Binary coded units (0=Disabled, 1..255)
134 outb(t, sch311x_wdt_data.runtime_reg + WDT_VAL);
137 static void sch311x_wdt_start(void)
139 spin_lock(&sch311x_wdt_data.io_lock);
141 /* set watchdog's timeout */
142 sch311x_wdt_set_timeout(timeout);
143 /* enable the watchdog */
144 /* -- General Purpose I/O Bit 6.0 --
145 * Bit 0, In/Out: 0 = Output, 1 = Input
146 * Bit 1, Polarity: 0 = No Invert, 1 = Invert
147 * Bit 2-3, Function select: 00 = GPI/O, 01 = LED1, 11 = WDT,
148 * 10 = Either Edge Triggered Intr.4
150 * Bit 7, Output Type: 0 = Push Pull Bit, 1 = Open Drain
152 outb(0x0e, sch311x_wdt_data.runtime_reg + GP60);
154 spin_unlock(&sch311x_wdt_data.io_lock);
158 static void sch311x_wdt_stop(void)
160 spin_lock(&sch311x_wdt_data.io_lock);
162 /* stop the watchdog */
163 outb(0x01, sch311x_wdt_data.runtime_reg + GP60);
164 /* disable timeout by setting it to 0 */
165 sch311x_wdt_set_timeout(0);
167 spin_unlock(&sch311x_wdt_data.io_lock);
170 static void sch311x_wdt_keepalive(void)
172 spin_lock(&sch311x_wdt_data.io_lock);
173 sch311x_wdt_set_timeout(timeout);
174 spin_unlock(&sch311x_wdt_data.io_lock);
177 static int sch311x_wdt_set_heartbeat(int t)
179 if (t < 1 || t > (255*60))
182 /* When new timeout is bigger then 255 seconds,
183 * we will round up to minutes (with a max of 255) */
185 t = (((t - 1) / 60) + 1) * 60;
191 static void sch311x_wdt_get_status(int *status)
193 unsigned char new_status;
197 spin_lock(&sch311x_wdt_data.io_lock);
199 /* -- Watchdog timer control --
200 * Bit 0 Status Bit: 0 = Timer counting, 1 = Timeout occurred
202 * Bit 2 Force Timeout: 1 = Forces WD timeout event (self-cleaning)
203 * Bit 3 P20 Force Timeout enabled:
204 * 0 = P20 activity does not generate the WD timeout event
205 * 1 = P20 Allows rising edge of P20, from the keyboard
206 * controller, to force the WD timeout event.
209 new_status = inb(sch311x_wdt_data.runtime_reg + WDT_CTRL);
210 if (new_status & 0x01)
211 *status |= WDIOF_CARDRESET;
213 spin_unlock(&sch311x_wdt_data.io_lock);
217 * /dev/watchdog handling
220 static ssize_t sch311x_wdt_write(struct file *file, const char __user *buf,
221 size_t count, loff_t *ppos)
227 sch311x_wdt_expect_close = 0;
229 for (i = 0; i != count; i++) {
231 if (get_user(c, buf + i))
234 sch311x_wdt_expect_close = 42;
237 sch311x_wdt_keepalive();
242 static long sch311x_wdt_ioctl(struct file *file, unsigned int cmd,
247 void __user *argp = (void __user *)arg;
248 int __user *p = argp;
249 static const struct watchdog_info ident = {
250 .options = WDIOF_KEEPALIVEPING |
253 .firmware_version = 1,
254 .identity = DRV_NAME,
258 case WDIOC_GETSUPPORT:
259 if (copy_to_user(argp, &ident, sizeof(ident)))
263 case WDIOC_GETSTATUS:
265 sch311x_wdt_get_status(&status);
266 return put_user(status, p);
268 case WDIOC_GETBOOTSTATUS:
269 return put_user(sch311x_wdt_data.boot_status, p);
271 case WDIOC_SETOPTIONS:
273 int options, retval = -EINVAL;
275 if (get_user(options, p))
277 if (options & WDIOS_DISABLECARD) {
281 if (options & WDIOS_ENABLECARD) {
287 case WDIOC_KEEPALIVE:
288 sch311x_wdt_keepalive();
291 case WDIOC_SETTIMEOUT:
292 if (get_user(new_timeout, p))
294 if (sch311x_wdt_set_heartbeat(new_timeout))
296 sch311x_wdt_keepalive();
298 case WDIOC_GETTIMEOUT:
299 return put_user(timeout, p);
306 static int sch311x_wdt_open(struct inode *inode, struct file *file)
308 if (test_and_set_bit(0, &sch311x_wdt_is_open))
314 return nonseekable_open(inode, file);
317 static int sch311x_wdt_close(struct inode *inode, struct file *file)
319 if (sch311x_wdt_expect_close == 42) {
322 pr_crit("Unexpected close, not stopping watchdog!\n");
323 sch311x_wdt_keepalive();
325 clear_bit(0, &sch311x_wdt_is_open);
326 sch311x_wdt_expect_close = 0;
334 static const struct file_operations sch311x_wdt_fops = {
335 .owner = THIS_MODULE,
337 .write = sch311x_wdt_write,
338 .unlocked_ioctl = sch311x_wdt_ioctl,
339 .open = sch311x_wdt_open,
340 .release = sch311x_wdt_close,
343 static struct miscdevice sch311x_wdt_miscdev = {
344 .minor = WATCHDOG_MINOR,
346 .fops = &sch311x_wdt_fops,
350 * Init & exit routines
353 static int __devinit sch311x_wdt_probe(struct platform_device *pdev)
355 struct device *dev = &pdev->dev;
358 spin_lock_init(&sch311x_wdt_data.io_lock);
360 if (!request_region(sch311x_wdt_data.runtime_reg + GP60, 1, DRV_NAME)) {
361 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
362 sch311x_wdt_data.runtime_reg + GP60,
363 sch311x_wdt_data.runtime_reg + GP60);
368 if (!request_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4,
370 dev_err(dev, "Failed to request region 0x%04x-0x%04x.\n",
371 sch311x_wdt_data.runtime_reg + WDT_TIME_OUT,
372 sch311x_wdt_data.runtime_reg + WDT_CTRL);
374 goto exit_release_region;
377 /* Make sure that the watchdog is not running */
380 /* Disable keyboard and mouse interaction and interrupt */
381 /* -- Watchdog timer configuration --
383 * Bit 1 Keyboard enable: 0* = No Reset, 1 = Reset WDT upon KBD Intr.
384 * Bit 2 Mouse enable: 0* = No Reset, 1 = Reset WDT upon Mouse Intr
386 * Bit 4-7 WDT Interrupt Mapping: (0000* = Disabled,
387 * 0001=IRQ1, 0010=(Invalid), 0011=IRQ3 to 1111=IRQ15)
389 outb(0, sch311x_wdt_data.runtime_reg + WDT_CFG);
391 /* Check that the heartbeat value is within it's range ;
392 * if not reset to the default */
393 if (sch311x_wdt_set_heartbeat(timeout)) {
394 sch311x_wdt_set_heartbeat(WATCHDOG_TIMEOUT);
395 dev_info(dev, "timeout value must be 1<=x<=15300, using %d\n",
399 /* Get status at boot */
400 sch311x_wdt_get_status(&sch311x_wdt_data.boot_status);
402 sch311x_wdt_miscdev.parent = dev;
404 err = misc_register(&sch311x_wdt_miscdev);
406 dev_err(dev, "cannot register miscdev on minor=%d (err=%d)\n",
407 WATCHDOG_MINOR, err);
408 goto exit_release_region2;
412 "SMSC SCH311x WDT initialized. timeout=%d sec (nowayout=%d)\n",
417 exit_release_region2:
418 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
420 release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
421 sch311x_wdt_data.runtime_reg = 0;
426 static int __devexit sch311x_wdt_remove(struct platform_device *pdev)
428 /* Stop the timer before we leave */
433 misc_deregister(&sch311x_wdt_miscdev);
434 release_region(sch311x_wdt_data.runtime_reg + WDT_TIME_OUT, 4);
435 release_region(sch311x_wdt_data.runtime_reg + GP60, 1);
436 sch311x_wdt_data.runtime_reg = 0;
440 static void sch311x_wdt_shutdown(struct platform_device *dev)
442 /* Turn the WDT off if we have a soft shutdown */
446 static struct platform_driver sch311x_wdt_driver = {
447 .probe = sch311x_wdt_probe,
448 .remove = __devexit_p(sch311x_wdt_remove),
449 .shutdown = sch311x_wdt_shutdown,
451 .owner = THIS_MODULE,
456 static int __init sch311x_detect(int sio_config_port, unsigned short *addr)
459 unsigned short base_addr;
460 unsigned char dev_id;
462 sch311x_sio_enter(sio_config_port);
464 /* Check device ID. We currently know about:
465 * SCH3112 (0x7c), SCH3114 (0x7d), and SCH3116 (0x7f). */
466 reg = force_id ? force_id : sch311x_sio_inb(sio_config_port, 0x20);
467 if (!(reg == 0x7c || reg == 0x7d || reg == 0x7f)) {
471 dev_id = reg == 0x7c ? 2 : reg == 0x7d ? 4 : 6;
473 /* Select logical device A (runtime registers) */
474 sch311x_sio_outb(sio_config_port, 0x07, 0x0a);
476 /* Check if Logical Device Register is currently active */
477 if ((sch311x_sio_inb(sio_config_port, 0x30) & 0x01) == 0)
478 pr_info("Seems that LDN 0x0a is not active...\n");
480 /* Get the base address of the runtime registers */
481 base_addr = (sch311x_sio_inb(sio_config_port, 0x60) << 8) |
482 sch311x_sio_inb(sio_config_port, 0x61);
484 pr_err("Base address not set\n");
490 pr_info("Found an SMSC SCH311%d chip at 0x%04x\n", dev_id, base_addr);
493 sch311x_sio_exit(sio_config_port);
497 static int __init sch311x_wdt_init(void)
499 int err, i, found = 0;
500 unsigned short addr = 0;
502 for (i = 0; !found && sch311x_ioports[i]; i++)
503 if (sch311x_detect(sch311x_ioports[i], &addr) == 0)
509 sch311x_wdt_data.runtime_reg = addr;
511 err = platform_driver_register(&sch311x_wdt_driver);
515 sch311x_wdt_pdev = platform_device_register_simple(DRV_NAME, addr,
518 if (IS_ERR(sch311x_wdt_pdev)) {
519 err = PTR_ERR(sch311x_wdt_pdev);
520 goto unreg_platform_driver;
525 unreg_platform_driver:
526 platform_driver_unregister(&sch311x_wdt_driver);
530 static void __exit sch311x_wdt_exit(void)
532 platform_device_unregister(sch311x_wdt_pdev);
533 platform_driver_unregister(&sch311x_wdt_driver);
536 module_init(sch311x_wdt_init);
537 module_exit(sch311x_wdt_exit);
539 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>");
540 MODULE_DESCRIPTION("SMSC SCH311x WatchDog Timer Driver");
541 MODULE_LICENSE("GPL");
542 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);