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