xref: /openbmc/linux/drivers/watchdog/ibmasr.c (revision 827634ad)
1 /*
2  * IBM Automatic Server Restart driver.
3  *
4  * Copyright (c) 2005 Andrey Panin <pazke@donpac.ru>
5  *
6  * Based on driver written by Pete Reynolds.
7  * Copyright (c) IBM Corporation, 1998-2004.
8  *
9  * This software may be used and distributed according to the terms
10  * of the GNU Public License, incorporated herein by reference.
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/fs.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/pci.h>
19 #include <linux/timer.h>
20 #include <linux/miscdevice.h>
21 #include <linux/watchdog.h>
22 #include <linux/dmi.h>
23 #include <linux/io.h>
24 #include <linux/uaccess.h>
25 
26 
27 enum {
28 	ASMTYPE_UNKNOWN,
29 	ASMTYPE_TOPAZ,
30 	ASMTYPE_JASPER,
31 	ASMTYPE_PEARL,
32 	ASMTYPE_JUNIPER,
33 	ASMTYPE_SPRUCE,
34 };
35 
36 #define TOPAZ_ASR_REG_OFFSET	4
37 #define TOPAZ_ASR_TOGGLE	0x40
38 #define TOPAZ_ASR_DISABLE	0x80
39 
40 /* PEARL ASR S/W REGISTER SUPERIO PORT ADDRESSES */
41 #define PEARL_BASE	0xe04
42 #define PEARL_WRITE	0xe06
43 #define PEARL_READ	0xe07
44 
45 #define PEARL_ASR_DISABLE_MASK	0x80	/* bit 7: disable = 1, enable = 0 */
46 #define PEARL_ASR_TOGGLE_MASK	0x40	/* bit 6: 0, then 1, then 0 */
47 
48 /* JASPER OFFSET FROM SIO BASE ADDR TO ASR S/W REGISTERS. */
49 #define JASPER_ASR_REG_OFFSET	0x38
50 
51 #define JASPER_ASR_DISABLE_MASK	0x01	/* bit 0: disable = 1, enable = 0 */
52 #define JASPER_ASR_TOGGLE_MASK	0x02	/* bit 1: 0, then 1, then 0 */
53 
54 #define JUNIPER_BASE_ADDRESS	0x54b	/* Base address of Juniper ASR */
55 #define JUNIPER_ASR_DISABLE_MASK 0x01	/* bit 0: disable = 1 enable = 0 */
56 #define JUNIPER_ASR_TOGGLE_MASK	0x02	/* bit 1: 0, then 1, then 0 */
57 
58 #define SPRUCE_BASE_ADDRESS	0x118e	/* Base address of Spruce ASR */
59 #define SPRUCE_ASR_DISABLE_MASK	0x01	/* bit 1: disable = 1 enable = 0 */
60 #define SPRUCE_ASR_TOGGLE_MASK	0x02	/* bit 0: 0, then 1, then 0 */
61 
62 
63 static bool nowayout = WATCHDOG_NOWAYOUT;
64 
65 static unsigned long asr_is_open;
66 static char asr_expect_close;
67 
68 static unsigned int asr_type, asr_base, asr_length;
69 static unsigned int asr_read_addr, asr_write_addr;
70 static unsigned char asr_toggle_mask, asr_disable_mask;
71 static DEFINE_SPINLOCK(asr_lock);
72 
73 static void __asr_toggle(void)
74 {
75 	unsigned char reg;
76 
77 	reg = inb(asr_read_addr);
78 
79 	outb(reg & ~asr_toggle_mask, asr_write_addr);
80 	reg = inb(asr_read_addr);
81 
82 	outb(reg | asr_toggle_mask, asr_write_addr);
83 	reg = inb(asr_read_addr);
84 
85 	outb(reg & ~asr_toggle_mask, asr_write_addr);
86 	reg = inb(asr_read_addr);
87 }
88 
89 static void asr_toggle(void)
90 {
91 	spin_lock(&asr_lock);
92 	__asr_toggle();
93 	spin_unlock(&asr_lock);
94 }
95 
96 static void asr_enable(void)
97 {
98 	unsigned char reg;
99 
100 	spin_lock(&asr_lock);
101 	if (asr_type == ASMTYPE_TOPAZ) {
102 		/* asr_write_addr == asr_read_addr */
103 		reg = inb(asr_read_addr);
104 		outb(reg & ~(TOPAZ_ASR_TOGGLE | TOPAZ_ASR_DISABLE),
105 		     asr_read_addr);
106 	} else {
107 		/*
108 		 * First make sure the hardware timer is reset by toggling
109 		 * ASR hardware timer line.
110 		 */
111 		__asr_toggle();
112 
113 		reg = inb(asr_read_addr);
114 		outb(reg & ~asr_disable_mask, asr_write_addr);
115 	}
116 	reg = inb(asr_read_addr);
117 	spin_unlock(&asr_lock);
118 }
119 
120 static void asr_disable(void)
121 {
122 	unsigned char reg;
123 
124 	spin_lock(&asr_lock);
125 	reg = inb(asr_read_addr);
126 
127 	if (asr_type == ASMTYPE_TOPAZ)
128 		/* asr_write_addr == asr_read_addr */
129 		outb(reg | TOPAZ_ASR_TOGGLE | TOPAZ_ASR_DISABLE,
130 		     asr_read_addr);
131 	else {
132 		outb(reg | asr_toggle_mask, asr_write_addr);
133 		reg = inb(asr_read_addr);
134 
135 		outb(reg | asr_disable_mask, asr_write_addr);
136 	}
137 	reg = inb(asr_read_addr);
138 	spin_unlock(&asr_lock);
139 }
140 
141 static int __init asr_get_base_address(void)
142 {
143 	unsigned char low, high;
144 	const char *type = "";
145 
146 	asr_length = 1;
147 
148 	switch (asr_type) {
149 	case ASMTYPE_TOPAZ:
150 		/* SELECT SuperIO CHIP FOR QUERYING
151 		   (WRITE 0x07 TO BOTH 0x2E and 0x2F) */
152 		outb(0x07, 0x2e);
153 		outb(0x07, 0x2f);
154 
155 		/* SELECT AND READ THE HIGH-NIBBLE OF THE GPIO BASE ADDRESS */
156 		outb(0x60, 0x2e);
157 		high = inb(0x2f);
158 
159 		/* SELECT AND READ THE LOW-NIBBLE OF THE GPIO BASE ADDRESS */
160 		outb(0x61, 0x2e);
161 		low = inb(0x2f);
162 
163 		asr_base = (high << 16) | low;
164 		asr_read_addr = asr_write_addr =
165 			asr_base + TOPAZ_ASR_REG_OFFSET;
166 		asr_length = 5;
167 
168 		break;
169 
170 	case ASMTYPE_JASPER:
171 		type = "Jaspers ";
172 #if 0
173 		u32 r;
174 		/* Suggested fix */
175 		pdev = pci_get_bus_and_slot(0, DEVFN(0x1f, 0));
176 		if (pdev == NULL)
177 			return -ENODEV;
178 		pci_read_config_dword(pdev, 0x58, &r);
179 		asr_base = r & 0xFFFE;
180 		pci_dev_put(pdev);
181 #else
182 		/* FIXME: need to use pci_config_lock here,
183 		   but it's not exported */
184 
185 /*		spin_lock_irqsave(&pci_config_lock, flags);*/
186 
187 		/* Select the SuperIO chip in the PCI I/O port register */
188 		outl(0x8000f858, 0xcf8);
189 
190 		/* BUS 0, Slot 1F, fnc 0, offset 58 */
191 
192 		/*
193 		 * Read the base address for the SuperIO chip.
194 		 * Only the lower 16 bits are valid, but the address is word
195 		 * aligned so the last bit must be masked off.
196 		 */
197 		asr_base = inl(0xcfc) & 0xfffe;
198 
199 /*		spin_unlock_irqrestore(&pci_config_lock, flags);*/
200 #endif
201 		asr_read_addr = asr_write_addr =
202 			asr_base + JASPER_ASR_REG_OFFSET;
203 		asr_toggle_mask = JASPER_ASR_TOGGLE_MASK;
204 		asr_disable_mask = JASPER_ASR_DISABLE_MASK;
205 		asr_length = JASPER_ASR_REG_OFFSET + 1;
206 
207 		break;
208 
209 	case ASMTYPE_PEARL:
210 		type = "Pearls ";
211 		asr_base = PEARL_BASE;
212 		asr_read_addr = PEARL_READ;
213 		asr_write_addr = PEARL_WRITE;
214 		asr_toggle_mask = PEARL_ASR_TOGGLE_MASK;
215 		asr_disable_mask = PEARL_ASR_DISABLE_MASK;
216 		asr_length = 4;
217 		break;
218 
219 	case ASMTYPE_JUNIPER:
220 		type = "Junipers ";
221 		asr_base = JUNIPER_BASE_ADDRESS;
222 		asr_read_addr = asr_write_addr = asr_base;
223 		asr_toggle_mask = JUNIPER_ASR_TOGGLE_MASK;
224 		asr_disable_mask = JUNIPER_ASR_DISABLE_MASK;
225 		break;
226 
227 	case ASMTYPE_SPRUCE:
228 		type = "Spruce's ";
229 		asr_base = SPRUCE_BASE_ADDRESS;
230 		asr_read_addr = asr_write_addr = asr_base;
231 		asr_toggle_mask = SPRUCE_ASR_TOGGLE_MASK;
232 		asr_disable_mask = SPRUCE_ASR_DISABLE_MASK;
233 		break;
234 	}
235 
236 	if (!request_region(asr_base, asr_length, "ibmasr")) {
237 		pr_err("address %#x already in use\n", asr_base);
238 		return -EBUSY;
239 	}
240 
241 	pr_info("found %sASR @ addr %#x\n", type, asr_base);
242 
243 	return 0;
244 }
245 
246 
247 static ssize_t asr_write(struct file *file, const char __user *buf,
248 			 size_t count, loff_t *ppos)
249 {
250 	if (count) {
251 		if (!nowayout) {
252 			size_t i;
253 
254 			/* In case it was set long ago */
255 			asr_expect_close = 0;
256 
257 			for (i = 0; i != count; i++) {
258 				char c;
259 				if (get_user(c, buf + i))
260 					return -EFAULT;
261 				if (c == 'V')
262 					asr_expect_close = 42;
263 			}
264 		}
265 		asr_toggle();
266 	}
267 	return count;
268 }
269 
270 static long asr_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
271 {
272 	static const struct watchdog_info ident = {
273 		.options =	WDIOF_KEEPALIVEPING |
274 				WDIOF_MAGICCLOSE,
275 		.identity =	"IBM ASR",
276 	};
277 	void __user *argp = (void __user *)arg;
278 	int __user *p = argp;
279 	int heartbeat;
280 
281 	switch (cmd) {
282 	case WDIOC_GETSUPPORT:
283 		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
284 	case WDIOC_GETSTATUS:
285 	case WDIOC_GETBOOTSTATUS:
286 		return put_user(0, p);
287 	case WDIOC_SETOPTIONS:
288 	{
289 		int new_options, retval = -EINVAL;
290 		if (get_user(new_options, p))
291 			return -EFAULT;
292 		if (new_options & WDIOS_DISABLECARD) {
293 			asr_disable();
294 			retval = 0;
295 		}
296 		if (new_options & WDIOS_ENABLECARD) {
297 			asr_enable();
298 			asr_toggle();
299 			retval = 0;
300 		}
301 		return retval;
302 	}
303 	case WDIOC_KEEPALIVE:
304 		asr_toggle();
305 		return 0;
306 	/*
307 	 * The hardware has a fixed timeout value, so no WDIOC_SETTIMEOUT
308 	 * and WDIOC_GETTIMEOUT always returns 256.
309 	 */
310 	case WDIOC_GETTIMEOUT:
311 		heartbeat = 256;
312 		return put_user(heartbeat, p);
313 	default:
314 		return -ENOTTY;
315 	}
316 }
317 
318 static int asr_open(struct inode *inode, struct file *file)
319 {
320 	if (test_and_set_bit(0, &asr_is_open))
321 		return -EBUSY;
322 
323 	asr_toggle();
324 	asr_enable();
325 
326 	return nonseekable_open(inode, file);
327 }
328 
329 static int asr_release(struct inode *inode, struct file *file)
330 {
331 	if (asr_expect_close == 42)
332 		asr_disable();
333 	else {
334 		pr_crit("unexpected close, not stopping watchdog!\n");
335 		asr_toggle();
336 	}
337 	clear_bit(0, &asr_is_open);
338 	asr_expect_close = 0;
339 	return 0;
340 }
341 
342 static const struct file_operations asr_fops = {
343 	.owner =		THIS_MODULE,
344 	.llseek =		no_llseek,
345 	.write =		asr_write,
346 	.unlocked_ioctl =	asr_ioctl,
347 	.open =			asr_open,
348 	.release =		asr_release,
349 };
350 
351 static struct miscdevice asr_miscdev = {
352 	.minor =	WATCHDOG_MINOR,
353 	.name =		"watchdog",
354 	.fops =		&asr_fops,
355 };
356 
357 
358 struct ibmasr_id {
359 	const char *desc;
360 	int type;
361 };
362 
363 static struct ibmasr_id ibmasr_id_table[] __initdata = {
364 	{ "IBM Automatic Server Restart - eserver xSeries 220", ASMTYPE_TOPAZ },
365 	{ "IBM Automatic Server Restart - Machine Type 8673", ASMTYPE_PEARL },
366 	{ "IBM Automatic Server Restart - Machine Type 8480", ASMTYPE_JASPER },
367 	{ "IBM Automatic Server Restart - Machine Type 8482", ASMTYPE_JUNIPER },
368 	{ "IBM Automatic Server Restart - Machine Type 8648", ASMTYPE_SPRUCE },
369 	{ NULL }
370 };
371 
372 static int __init ibmasr_init(void)
373 {
374 	struct ibmasr_id *id;
375 	int rc;
376 
377 	for (id = ibmasr_id_table; id->desc; id++) {
378 		if (dmi_find_device(DMI_DEV_TYPE_OTHER, id->desc, NULL)) {
379 			asr_type = id->type;
380 			break;
381 		}
382 	}
383 
384 	if (!asr_type)
385 		return -ENODEV;
386 
387 	rc = asr_get_base_address();
388 	if (rc)
389 		return rc;
390 
391 	rc = misc_register(&asr_miscdev);
392 	if (rc < 0) {
393 		release_region(asr_base, asr_length);
394 		pr_err("failed to register misc device\n");
395 		return rc;
396 	}
397 
398 	return 0;
399 }
400 
401 static void __exit ibmasr_exit(void)
402 {
403 	if (!nowayout)
404 		asr_disable();
405 
406 	misc_deregister(&asr_miscdev);
407 
408 	release_region(asr_base, asr_length);
409 }
410 
411 module_init(ibmasr_init);
412 module_exit(ibmasr_exit);
413 
414 module_param(nowayout, bool, 0);
415 MODULE_PARM_DESC(nowayout,
416 	"Watchdog cannot be stopped once started (default="
417 				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
418 
419 MODULE_DESCRIPTION("IBM Automatic Server Restart driver");
420 MODULE_AUTHOR("Andrey Panin");
421 MODULE_LICENSE("GPL");
422