xref: /openbmc/linux/drivers/watchdog/iTCO_vendor_support.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 /*
105  *	Vendor Support: 2
106  *	Board: Super Micro Computer Inc. P4SBx, P4DPx
107  *	iTCO chipset: ICH4
108  *
109  *	Code contributed by: R. Seretny <lkpatches@paypc.com>
110  *	Documentation obtained by R. Seretny from SuperMicro Technical Support
111  *
112  *	To enable Watchdog function:
113  *	 1. BIOS
114  *	  For P4SBx:
115  *	  BIOS setup -> Advanced -> Integrated Peripherals -> Watch Dog Feature
116  *	  For P4DPx:
117  *	  BIOS setup -> Advanced -> I/O Device Configuration -> Watch Dog
118  *	 This setting enables or disables Watchdog function. When enabled, the
119  *	 default watchdog timer is set to be 5 minutes (about 4m35s). It is
120  *	 enough to load and run the OS. The application (service or driver) has
121  *	 to take over the control once OS is running up and before watchdog
122  *	 expires.
123  *
124  *	 2. JUMPER
125  *	  For P4SBx: JP39
126  *	  For P4DPx: JP37
127  *	  This jumper is used for safety.  Closed is enabled. This jumper
128  *	  prevents user enables watchdog in BIOS by accident.
129  *
130  *	 To enable Watch Dog function, both BIOS and JUMPER must be enabled.
131  *
132  *	The documentation lists motherboards P4SBx and P4DPx series as of
133  *	20-March-2002. However, this code works flawlessly with much newer
134  *	motherboards, such as my X6DHR-8G2 (SuperServer 6014H-82).
135  *
136  *	The original iTCO driver as written does not actually reset the
137  *	watchdog timer on these machines, as a result they reboot after five
138  *	minutes.
139  *
140  *	NOTE: You may leave the Watchdog function disabled in the SuperMicro
141  *	BIOS to avoid a "boot-race"... This driver will enable watchdog
142  *	functionality even if it's disabled in the BIOS once the /dev/watchdog
143  *	file is opened.
144  */
145 
146 /* I/O Port's */
147 #define SM_REGINDEX	0x2e	/* SuperMicro ICH4+ Register Index */
148 #define SM_DATAIO	0x2f	/* SuperMicro ICH4+ Register Data I/O */
149 
150 /* Control Register's */
151 #define SM_CTLPAGESW	0x07	/* SuperMicro ICH4+ Control Page Switch */
152 #define SM_CTLPAGE	0x08	/* SuperMicro ICH4+ Control Page Num */
153 
154 #define SM_WATCHENABLE	0x30	/* Watchdog enable: Bit 0: 0=off, 1=on */
155 
156 #define SM_WATCHPAGE	0x87	/* Watchdog unlock control page */
157 
158 #define SM_ENDWATCH	0xAA	/* Watchdog lock control page */
159 
160 #define SM_COUNTMODE	0xf5	/* Watchdog count mode select */
161 				/* (Bit 3: 0 = seconds, 1 = minutes */
162 
163 #define SM_WATCHTIMER	0xf6	/* 8-bits, Watchdog timer counter (RW) */
164 
165 #define SM_RESETCONTROL	0xf7	/* Watchdog reset control */
166 				/* Bit 6: timer is reset by kbd interrupt */
167 				/* Bit 7: timer is reset by mouse interrupt */
168 
169 static void supermicro_new_unlock_watchdog(void)
170 {
171 	/* Write 0x87 to port 0x2e twice */
172 	outb(SM_WATCHPAGE, SM_REGINDEX);
173 	outb(SM_WATCHPAGE, SM_REGINDEX);
174 	/* Switch to watchdog control page */
175 	outb(SM_CTLPAGESW, SM_REGINDEX);
176 	outb(SM_CTLPAGE, SM_DATAIO);
177 }
178 
179 static void supermicro_new_lock_watchdog(void)
180 {
181 	outb(SM_ENDWATCH, SM_REGINDEX);
182 }
183 
184 static void supermicro_new_pre_start(unsigned int heartbeat)
185 {
186 	unsigned int val;
187 
188 	supermicro_new_unlock_watchdog();
189 
190 	/* Watchdog timer setting needs to be in seconds*/
191 	outb(SM_COUNTMODE, SM_REGINDEX);
192 	val = inb(SM_DATAIO);
193 	val &= 0xF7;
194 	outb(val, SM_DATAIO);
195 
196 	/* Write heartbeat interval to WDOG */
197 	outb(SM_WATCHTIMER, SM_REGINDEX);
198 	outb((heartbeat & 255), SM_DATAIO);
199 
200 	/* Make sure keyboard/mouse interrupts don't interfere */
201 	outb(SM_RESETCONTROL, SM_REGINDEX);
202 	val = inb(SM_DATAIO);
203 	val &= 0x3f;
204 	outb(val, SM_DATAIO);
205 
206 	/* enable watchdog by setting bit 0 of Watchdog Enable to 1 */
207 	outb(SM_WATCHENABLE, SM_REGINDEX);
208 	val = inb(SM_DATAIO);
209 	val |= 0x01;
210 	outb(val, SM_DATAIO);
211 
212 	supermicro_new_lock_watchdog();
213 }
214 
215 static void supermicro_new_pre_stop(void)
216 {
217 	unsigned int val;
218 
219 	supermicro_new_unlock_watchdog();
220 
221 	/* disable watchdog by setting bit 0 of Watchdog Enable to 0 */
222 	outb(SM_WATCHENABLE, SM_REGINDEX);
223 	val = inb(SM_DATAIO);
224 	val &= 0xFE;
225 	outb(val, SM_DATAIO);
226 
227 	supermicro_new_lock_watchdog();
228 }
229 
230 static void supermicro_new_pre_set_heartbeat(unsigned int heartbeat)
231 {
232 	supermicro_new_unlock_watchdog();
233 
234 	/* reset watchdog timeout to heartveat value */
235 	outb(SM_WATCHTIMER, SM_REGINDEX);
236 	outb((heartbeat & 255), SM_DATAIO);
237 
238 	supermicro_new_lock_watchdog();
239 }
240 
241 /*
242  *	Vendor Support: 911
243  *	Board: Some Intel ICHx based motherboards
244  *	iTCO chipset: ICH7+
245  *
246  *	Some Intel motherboards have a broken BIOS implementation: i.e.
247  *	the SMI handler clear's the TIMEOUT bit in the TC01_STS register
248  *	and does not reload the time. Thus the TCO watchdog does not reboot
249  *	the system.
250  *
251  *	These are the conclusions of Andriy Gapon <avg@icyb.net.ua> after
252  *	debugging: the SMI handler is quite simple - it tests value in
253  *	TCO1_CNT against 0x800, i.e. checks TCO_TMR_HLT. If the bit is set
254  *	the handler goes into an infinite loop, apparently to allow the
255  *	second timeout and reboot. Otherwise it simply clears TIMEOUT bit
256  *	in TCO1_STS and that's it.
257  *	So the logic seems to be reversed, because it is hard to see how
258  *	TIMEOUT can get set to 1 and SMI generated when TCO_TMR_HLT is set
259  *	(other than a transitional effect).
260  *
261  *	The only fix found to get the motherboard(s) to reboot is to put
262  *	the glb_smi_en bit to 0. This is a dirty hack that bypasses the
263  *	broken code by disabling Global SMI.
264  *
265  *	WARNING: globally disabling SMI could possibly lead to dramatic
266  *	problems, especially on laptops! I.e. various ACPI things where
267  *	SMI is used for communication between OS and firmware.
268  *
269  *	Don't use this fix if you don't need to!!!
270  */
271 
272 static void broken_bios_start(unsigned long acpibase)
273 {
274 	unsigned long val32;
275 
276 	val32 = inl(SMI_EN);
277 	/* Bit 13: TCO_EN     -> 0 = Disables TCO logic generating an SMI#
278 	   Bit  0: GBL_SMI_EN -> 0 = No SMI# will be generated by ICH. */
279 	val32 &= 0xffffdffe;
280 	outl(val32, SMI_EN);
281 }
282 
283 static void broken_bios_stop(unsigned long acpibase)
284 {
285 	unsigned long val32;
286 
287 	val32 = inl(SMI_EN);
288 	/* Bit 13: TCO_EN     -> 1 = Enables TCO logic generating an SMI#
289 	   Bit  0: GBL_SMI_EN -> 1 = Turn global SMI on again. */
290 	val32 |= 0x00002001;
291 	outl(val32, SMI_EN);
292 }
293 
294 /*
295  *	Generic Support Functions
296  */
297 
298 void iTCO_vendor_pre_start(unsigned long acpibase,
299 			   unsigned int heartbeat)
300 {
301 	switch (vendorsupport) {
302 	case SUPERMICRO_OLD_BOARD:
303 		supermicro_old_pre_start(acpibase);
304 		break;
305 	case SUPERMICRO_NEW_BOARD:
306 		supermicro_new_pre_start(heartbeat);
307 		break;
308 	case BROKEN_BIOS:
309 		broken_bios_start(acpibase);
310 		break;
311 	}
312 }
313 EXPORT_SYMBOL(iTCO_vendor_pre_start);
314 
315 void iTCO_vendor_pre_stop(unsigned long acpibase)
316 {
317 	switch (vendorsupport) {
318 	case SUPERMICRO_OLD_BOARD:
319 		supermicro_old_pre_stop(acpibase);
320 		break;
321 	case SUPERMICRO_NEW_BOARD:
322 		supermicro_new_pre_stop();
323 		break;
324 	case BROKEN_BIOS:
325 		broken_bios_stop(acpibase);
326 		break;
327 	}
328 }
329 EXPORT_SYMBOL(iTCO_vendor_pre_stop);
330 
331 void iTCO_vendor_pre_keepalive(unsigned long acpibase, unsigned int heartbeat)
332 {
333 	if (vendorsupport == SUPERMICRO_NEW_BOARD)
334 		supermicro_new_pre_set_heartbeat(heartbeat);
335 }
336 EXPORT_SYMBOL(iTCO_vendor_pre_keepalive);
337 
338 void iTCO_vendor_pre_set_heartbeat(unsigned int heartbeat)
339 {
340 	if (vendorsupport == SUPERMICRO_NEW_BOARD)
341 		supermicro_new_pre_set_heartbeat(heartbeat);
342 }
343 EXPORT_SYMBOL(iTCO_vendor_pre_set_heartbeat);
344 
345 int iTCO_vendor_check_noreboot_on(void)
346 {
347 	switch (vendorsupport) {
348 	case SUPERMICRO_OLD_BOARD:
349 		return 0;
350 	default:
351 		return 1;
352 	}
353 }
354 EXPORT_SYMBOL(iTCO_vendor_check_noreboot_on);
355 
356 static int __init iTCO_vendor_init_module(void)
357 {
358 	printk(KERN_INFO PFX "vendor-support=%d\n", vendorsupport);
359 	return 0;
360 }
361 
362 static void __exit iTCO_vendor_exit_module(void)
363 {
364 	printk(KERN_INFO PFX "Module Unloaded\n");
365 }
366 
367 module_init(iTCO_vendor_init_module);
368 module_exit(iTCO_vendor_exit_module);
369 
370 MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>, "
371 		"R. Seretny <lkpatches@paypc.com>");
372 MODULE_DESCRIPTION("Intel TCO Vendor Specific WatchDog Timer Driver Support");
373 MODULE_VERSION(DRV_VERSION);
374 MODULE_LICENSE("GPL");
375 
376