1 /*
2  *	intel TCO vendor specific watchdog driver support
3  *
4  *	(c) Copyright 2006-2009 Wim Van Sebroeck <wim@iguana.be>.
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License
8  *	as published by the Free Software Foundation; either version
9  *	2 of the License, or (at your option) any later version.
10  *
11  *	Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor
12  *	provide warranty for any of this software. This material is
13  *	provided "AS-IS" and at no charge.
14  */
15 
16 /*
17  *	Includes, defines, variables, module parameters, ...
18  */
19 
20 /* Module and version information */
21 #define DRV_NAME	"iTCO_vendor_support"
22 #define DRV_VERSION	"1.04"
23 #define PFX		DRV_NAME ": "
24 
25 /* Includes */
26 #include <linux/module.h>		/* For module specific items */
27 #include <linux/moduleparam.h>		/* For new moduleparam's */
28 #include <linux/types.h>		/* For standard types (like size_t) */
29 #include <linux/errno.h>		/* For the -ENODEV/... values */
30 #include <linux/kernel.h>		/* For printk/panic/... */
31 #include <linux/init.h>			/* For __init/__exit/... */
32 #include <linux/ioport.h>		/* For io-port access */
33 #include <linux/io.h>			/* For inb/outb/... */
34 
35 #include "iTCO_vendor.h"
36 
37 /* iTCO defines */
38 #define	SMI_EN		(acpibase + 0x30) /* SMI Control and Enable Register */
39 #define	TCOBASE		(acpibase + 0x60) /* TCO base address */
40 #define	TCO1_STS	(TCOBASE + 0x04)  /* TCO1 Status Register */
41 
42 /* List of vendor support modes */
43 /* SuperMicro Pentium 3 Era 370SSE+-OEM1/P3TSSE */
44 #define SUPERMICRO_OLD_BOARD	1
45 /* SuperMicro Pentium 4 / Xeon 4 / EMT64T Era Systems */
46 #define SUPERMICRO_NEW_BOARD	2
47 /* Broken BIOS */
48 #define BROKEN_BIOS		911
49 
50 static int vendorsupport;
51 module_param(vendorsupport, int, 0);
52 MODULE_PARM_DESC(vendorsupport, "iTCO vendor specific support mode, default="
53 			"0 (none), 1=SuperMicro Pent3, 2=SuperMicro Pent4+, "
54 							"911=Broken SMI BIOS");
55 
56 /*
57  *	Vendor Specific Support
58  */
59 
60 /*
61  *	Vendor Support: 1
62  *	Board: Super Micro Computer Inc. 370SSE+-OEM1/P3TSSE
63  *	iTCO chipset: ICH2
64  *
65  *	Code contributed by: R. Seretny <lkpatches@paypc.com>
66  *	Documentation obtained by R. Seretny from SuperMicro Technical Support
67  *
68  *	To enable Watchdog function:
69  *	    BIOS setup -> Power -> TCO Logic SMI Enable -> Within5Minutes
70  *	    This setting enables SMI to clear the watchdog expired flag.
71  *	    If BIOS or CPU fail which may cause SMI hang, then system will
72  *	    reboot. When application starts to use watchdog function,
73  *	    application has to take over the control from SMI.
74  *
75  *	    For P3TSSE, J36 jumper needs to be removed to enable the Watchdog
76  *	    function.
77  *
78  *	    Note: The system will reboot when Expire Flag is set TWICE.
79  *	    So, if the watchdog timer is 20 seconds, then the maximum hang
80  *	    time is about 40 seconds, and the minimum hang time is about
81  *	    20.6 seconds.
82  */
83 
84 static void supermicro_old_pre_start(unsigned long acpibase)
85 {
86 	unsigned long val32;
87 
88 	/* Bit 13: TCO_EN -> 0 = Disables TCO logic generating an SMI# */
89 	val32 = inl(SMI_EN);
90 	val32 &= 0xffffdfff;	/* Turn off SMI clearing watchdog */
91 	outl(val32, SMI_EN);	/* Needed to activate watchdog */
92 }
93 
94 static void supermicro_old_pre_stop(unsigned long acpibase)
95 {
96 	unsigned long val32;
97 
98 	/* Bit 13: TCO_EN -> 1 = Enables the TCO logic to generate SMI# */
99 	val32 = inl(SMI_EN);
100 	val32 |= 0x00002000;	/* Turn on SMI clearing watchdog */
101 	outl(val32, SMI_EN);	/* Needed to deactivate watchdog */
102 }
103 
104 static void supermicro_old_pre_keepalive(unsigned long acpibase)
105 {
106 	/* Reload TCO Timer (done in iTCO_wdt_keepalive) + */
107 	/* Clear "Expire Flag" (Bit 3 of TC01_STS register) */
108 	outb(0x08, TCO1_STS);
109 }
110 
111 /*
112  *	Vendor Support: 2
113  *	Board: Super Micro Computer Inc. P4SBx, P4DPx
114  *	iTCO chipset: ICH4
115  *
116  *	Code contributed by: R. Seretny <lkpatches@paypc.com>
117  *	Documentation obtained by R. Seretny from SuperMicro Technical Support
118  *
119  *	To enable Watchdog function:
120  *	 1. BIOS
121  *	  For P4SBx:
122  *	  BIOS setup -> Advanced -> Integrated Peripherals -> Watch Dog Feature
123  *	  For P4DPx:
124  *	  BIOS setup -> Advanced -> I/O Device Configuration -> Watch Dog
125  *	 This setting enables or disables Watchdog function. When enabled, the
126  *	 default watchdog timer is set to be 5 minutes (about 4m35s). It is
127  *	 enough to load and run the OS. The application (service or driver) has
128  *	 to take over the control once OS is running up and before watchdog
129  *	 expires.
130  *
131  *	 2. JUMPER
132  *	  For P4SBx: JP39
133  *	  For P4DPx: JP37
134  *	  This jumper is used for safety.  Closed is enabled. This jumper
135  *	  prevents user enables watchdog in BIOS by accident.
136  *
137  *	 To enable Watch Dog function, both BIOS and JUMPER must be enabled.
138  *
139  *	The documentation lists motherboards P4SBx and P4DPx series as of
140  *	20-March-2002. However, this code works flawlessly with much newer
141  *	motherboards, such as my X6DHR-8G2 (SuperServer 6014H-82).
142  *
143  *	The original iTCO driver as written does not actually reset the
144  *	watchdog timer on these machines, as a result they reboot after five
145  *	minutes.
146  *
147  *	NOTE: You may leave the Watchdog function disabled in the SuperMicro
148  *	BIOS to avoid a "boot-race"... This driver will enable watchdog
149  *	functionality even if it's disabled in the BIOS once the /dev/watchdog
150  *	file is opened.
151  */
152 
153 /* I/O Port's */
154 #define SM_REGINDEX	0x2e	/* SuperMicro ICH4+ Register Index */
155 #define SM_DATAIO	0x2f	/* SuperMicro ICH4+ Register Data I/O */
156 
157 /* Control Register's */
158 #define SM_CTLPAGESW	0x07	/* SuperMicro ICH4+ Control Page Switch */
159 #define SM_CTLPAGE	0x08	/* SuperMicro ICH4+ Control Page Num */
160 
161 #define SM_WATCHENABLE	0x30	/* Watchdog enable: Bit 0: 0=off, 1=on */
162 
163 #define SM_WATCHPAGE	0x87	/* Watchdog unlock control page */
164 
165 #define SM_ENDWATCH	0xAA	/* Watchdog lock control page */
166 
167 #define SM_COUNTMODE	0xf5	/* Watchdog count mode select */
168 				/* (Bit 3: 0 = seconds, 1 = minutes */
169 
170 #define SM_WATCHTIMER	0xf6	/* 8-bits, Watchdog timer counter (RW) */
171 
172 #define SM_RESETCONTROL	0xf7	/* Watchdog reset control */
173 				/* Bit 6: timer is reset by kbd interrupt */
174 				/* Bit 7: timer is reset by mouse interrupt */
175 
176 static void supermicro_new_unlock_watchdog(void)
177 {
178 	/* Write 0x87 to port 0x2e twice */
179 	outb(SM_WATCHPAGE, SM_REGINDEX);
180 	outb(SM_WATCHPAGE, SM_REGINDEX);
181 	/* Switch to watchdog control page */
182 	outb(SM_CTLPAGESW, SM_REGINDEX);
183 	outb(SM_CTLPAGE, SM_DATAIO);
184 }
185 
186 static void supermicro_new_lock_watchdog(void)
187 {
188 	outb(SM_ENDWATCH, SM_REGINDEX);
189 }
190 
191 static void supermicro_new_pre_start(unsigned int heartbeat)
192 {
193 	unsigned int val;
194 
195 	supermicro_new_unlock_watchdog();
196 
197 	/* Watchdog timer setting needs to be in seconds*/
198 	outb(SM_COUNTMODE, SM_REGINDEX);
199 	val = inb(SM_DATAIO);
200 	val &= 0xF7;
201 	outb(val, SM_DATAIO);
202 
203 	/* Write heartbeat interval to WDOG */
204 	outb(SM_WATCHTIMER, SM_REGINDEX);
205 	outb((heartbeat & 255), SM_DATAIO);
206 
207 	/* Make sure keyboard/mouse interrupts don't interfere */
208 	outb(SM_RESETCONTROL, SM_REGINDEX);
209 	val = inb(SM_DATAIO);
210 	val &= 0x3f;
211 	outb(val, SM_DATAIO);
212 
213 	/* enable watchdog by setting bit 0 of Watchdog Enable to 1 */
214 	outb(SM_WATCHENABLE, SM_REGINDEX);
215 	val = inb(SM_DATAIO);
216 	val |= 0x01;
217 	outb(val, SM_DATAIO);
218 
219 	supermicro_new_lock_watchdog();
220 }
221 
222 static void supermicro_new_pre_stop(void)
223 {
224 	unsigned int val;
225 
226 	supermicro_new_unlock_watchdog();
227 
228 	/* disable watchdog by setting bit 0 of Watchdog Enable to 0 */
229 	outb(SM_WATCHENABLE, SM_REGINDEX);
230 	val = inb(SM_DATAIO);
231 	val &= 0xFE;
232 	outb(val, SM_DATAIO);
233 
234 	supermicro_new_lock_watchdog();
235 }
236 
237 static void supermicro_new_pre_set_heartbeat(unsigned int heartbeat)
238 {
239 	supermicro_new_unlock_watchdog();
240 
241 	/* reset watchdog timeout to heartveat value */
242 	outb(SM_WATCHTIMER, SM_REGINDEX);
243 	outb((heartbeat & 255), SM_DATAIO);
244 
245 	supermicro_new_lock_watchdog();
246 }
247 
248 /*
249  *	Vendor Support: 911
250  *	Board: Some Intel ICHx based motherboards
251  *	iTCO chipset: ICH7+
252  *
253  *	Some Intel motherboards have a broken BIOS implementation: i.e.
254  *	the SMI handler clear's the TIMEOUT bit in the TC01_STS register
255  *	and does not reload the time. Thus the TCO watchdog does not reboot
256  *	the system.
257  *
258  *	These are the conclusions of Andriy Gapon <avg@icyb.net.ua> after
259  *	debugging: the SMI handler is quite simple - it tests value in
260  *	TCO1_CNT against 0x800, i.e. checks TCO_TMR_HLT. If the bit is set
261  *	the handler goes into an infinite loop, apparently to allow the
262  *	second timeout and reboot. Otherwise it simply clears TIMEOUT bit
263  *	in TCO1_STS and that's it.
264  *	So the logic seems to be reversed, because it is hard to see how
265  *	TIMEOUT can get set to 1 and SMI generated when TCO_TMR_HLT is set
266  *	(other than a transitional effect).
267  *
268  *	The only fix found to get the motherboard(s) to reboot is to put
269  *	the glb_smi_en bit to 0. This is a dirty hack that bypasses the
270  *	broken code by disabling Global SMI.
271  *
272  *	WARNING: globally disabling SMI could possibly lead to dramatic
273  *	problems, especially on laptops! I.e. various ACPI things where
274  *	SMI is used for communication between OS and firmware.
275  *
276  *	Don't use this fix if you don't need to!!!
277  */
278 
279 static void broken_bios_start(unsigned long acpibase)
280 {
281 	unsigned long val32;
282 
283 	val32 = inl(SMI_EN);
284 	/* Bit 13: TCO_EN     -> 0 = Disables TCO logic generating an SMI#
285 	   Bit  0: GBL_SMI_EN -> 0 = No SMI# will be generated by ICH. */
286 	val32 &= 0xffffdffe;
287 	outl(val32, SMI_EN);
288 }
289 
290 static void broken_bios_stop(unsigned long acpibase)
291 {
292 	unsigned long val32;
293 
294 	val32 = inl(SMI_EN);
295 	/* Bit 13: TCO_EN     -> 1 = Enables TCO logic generating an SMI#
296 	   Bit  0: GBL_SMI_EN -> 1 = Turn global SMI on again. */
297 	val32 |= 0x00002001;
298 	outl(val32, SMI_EN);
299 }
300 
301 /*
302  *	Generic Support Functions
303  */
304 
305 void iTCO_vendor_pre_start(unsigned long acpibase,
306 			   unsigned int heartbeat)
307 {
308 	switch (vendorsupport) {
309 	case SUPERMICRO_OLD_BOARD:
310 		supermicro_old_pre_start(acpibase);
311 		break;
312 	case SUPERMICRO_NEW_BOARD:
313 		supermicro_new_pre_start(heartbeat);
314 		break;
315 	case BROKEN_BIOS:
316 		broken_bios_start(acpibase);
317 		break;
318 	}
319 }
320 EXPORT_SYMBOL(iTCO_vendor_pre_start);
321 
322 void iTCO_vendor_pre_stop(unsigned long acpibase)
323 {
324 	switch (vendorsupport) {
325 	case SUPERMICRO_OLD_BOARD:
326 		supermicro_old_pre_stop(acpibase);
327 		break;
328 	case SUPERMICRO_NEW_BOARD:
329 		supermicro_new_pre_stop();
330 		break;
331 	case BROKEN_BIOS:
332 		broken_bios_stop(acpibase);
333 		break;
334 	}
335 }
336 EXPORT_SYMBOL(iTCO_vendor_pre_stop);
337 
338 void iTCO_vendor_pre_keepalive(unsigned long acpibase, unsigned int heartbeat)
339 {
340 	if (vendorsupport == SUPERMICRO_OLD_BOARD)
341 		supermicro_old_pre_keepalive(acpibase);
342 	else if (vendorsupport == SUPERMICRO_NEW_BOARD)
343 		supermicro_new_pre_set_heartbeat(heartbeat);
344 }
345 EXPORT_SYMBOL(iTCO_vendor_pre_keepalive);
346 
347 void iTCO_vendor_pre_set_heartbeat(unsigned int heartbeat)
348 {
349 	if (vendorsupport == SUPERMICRO_NEW_BOARD)
350 		supermicro_new_pre_set_heartbeat(heartbeat);
351 }
352 EXPORT_SYMBOL(iTCO_vendor_pre_set_heartbeat);
353 
354 int iTCO_vendor_check_noreboot_on(void)
355 {
356 	switch (vendorsupport) {
357 	case SUPERMICRO_OLD_BOARD:
358 		return 0;
359 	default:
360 		return 1;
361 	}
362 }
363 EXPORT_SYMBOL(iTCO_vendor_check_noreboot_on);
364 
365 static int __init iTCO_vendor_init_module(void)
366 {
367 	printk(KERN_INFO PFX "vendor-support=%d\n", vendorsupport);
368 	return 0;
369 }
370 
371 static void __exit iTCO_vendor_exit_module(void)
372 {
373 	printk(KERN_INFO PFX "Module Unloaded\n");
374 }
375 
376 module_init(iTCO_vendor_init_module);
377 module_exit(iTCO_vendor_exit_module);
378 
379 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>, "
380 		"R. Seretny <lkpatches@paypc.com>");
381 MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support");
382 MODULE_VERSION(DRV_VERSION);
383 MODULE_LICENSE("GPL");
384 
385