summaryrefslogtreecommitdiffstats
path: root/drivers/watchdog/sp5100_tco.c
blob: 93bd302ae7c5d054063d339b090dd75cd692fbde (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	sp5100_tco :	TCO timer driver for sp5100 chipsets
 *
 *	(c) Copyright 2009 Google Inc., All Rights Reserved.
 *
 *	Based on i8xx_tco.c:
 *	(c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
 *	Reserved.
 *				http://www.kernelconcepts.de
 *
 *	See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide",
 *	    AMD Publication 45482 "AMD SB800-Series Southbridges Register
 *	                                                      Reference Guide"
 *	    AMD Publication 48751 "BIOS and Kernel Developer’s Guide (BKDG)
 *				for AMD Family 16h Models 00h-0Fh Processors"
 *	    AMD Publication 51192 "AMD Bolton FCH Register Reference Guide"
 *	    AMD Publication 52740 "BIOS and Kernel Developer’s Guide (BKDG)
 *				for AMD Family 16h Models 30h-3Fh Processors"
 */

/*
 *	Includes, defines, variables, module parameters, ...
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/watchdog.h>

#include "sp5100_tco.h"

#define TCO_DRIVER_NAME	"sp5100-tco"

/* internal variables */

enum tco_reg_layout {
	sp5100, sb800, efch
};

struct sp5100_tco {
	struct watchdog_device wdd;
	void __iomem *tcobase;
	enum tco_reg_layout tco_reg_layout;
};

/* the watchdog platform device */
static struct platform_device *sp5100_tco_platform_device;
/* the associated PCI device */
static struct pci_dev *sp5100_tco_pci;

/* module parameters */

#define WATCHDOG_HEARTBEAT 60	/* 60 sec default heartbeat. */
static int heartbeat = WATCHDOG_HEARTBEAT;  /* in seconds */
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
		 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started."
		" (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

/*
 * Some TCO specific functions
 */

static enum tco_reg_layout tco_reg_layout(struct pci_dev *dev)
{
	if (dev->vendor == PCI_VENDOR_ID_ATI &&
	    dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
	    dev->revision < 0x40) {
		return sp5100;
	} else if (dev->vendor == PCI_VENDOR_ID_AMD &&
	    ((dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
	     dev->revision >= 0x41) ||
	    (dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
	     dev->revision >= 0x49))) {
		return efch;
	}
	return sb800;
}

static int tco_timer_start(struct watchdog_device *wdd)
{
	struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
	u32 val;

	val = readl(SP5100_WDT_CONTROL(tco->tcobase));
	val |= SP5100_WDT_START_STOP_BIT;
	writel(val, SP5100_WDT_CONTROL(tco->tcobase));

	return 0;
}

static int tco_timer_stop(struct watchdog_device *wdd)
{
	struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
	u32 val;

	val = readl(SP5100_WDT_CONTROL(tco->tcobase));
	val &= ~SP5100_WDT_START_STOP_BIT;
	writel(val, SP5100_WDT_CONTROL(tco->tcobase));

	return 0;
}

static int tco_timer_ping(struct watchdog_device *wdd)
{
	struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
	u32 val;

	val = readl(SP5100_WDT_CONTROL(tco->tcobase));
	val |= SP5100_WDT_TRIGGER_BIT;
	writel(val, SP5100_WDT_CONTROL(tco->tcobase));

	return 0;
}

static int tco_timer_set_timeout(struct watchdog_device *wdd,
				 unsigned int t)
{
	struct sp5100_tco *tco = watchdog_get_drvdata(wdd);

	/* Write new heartbeat to watchdog */
	writel(t, SP5100_WDT_COUNT(tco->tcobase));

	wdd->timeout = t;

	return 0;
}

static u8 sp5100_tco_read_pm_reg8(u8 index)
{
	outb(index, SP5100_IO_PM_INDEX_REG);
	return inb(SP5100_IO_PM_DATA_REG);
}

static void sp5100_tco_update_pm_reg8(u8 index, u8 reset, u8 set)
{
	u8 val;

	outb(index, SP5100_IO_PM_INDEX_REG);
	val = inb(SP5100_IO_PM_DATA_REG);
	val &= reset;
	val |= set;
	outb(val, SP5100_IO_PM_DATA_REG);
}

static void tco_timer_enable(struct sp5100_tco *tco)
{
	u32 val;

	switch (tco->tco_reg_layout) {
	case sb800:
		/* For SB800 or later */
		/* Set the Watchdog timer resolution to 1 sec */
		sp5100_tco_update_pm_reg8(SB800_PM_WATCHDOG_CONFIG,
					  0xff, SB800_PM_WATCHDOG_SECOND_RES);

		/* Enable watchdog decode bit and watchdog timer */
		sp5100_tco_update_pm_reg8(SB800_PM_WATCHDOG_CONTROL,
					  ~SB800_PM_WATCHDOG_DISABLE,
					  SB800_PCI_WATCHDOG_DECODE_EN);
		break;
	case sp5100:
		/* For SP5100 or SB7x0 */
		/* Enable watchdog decode bit */
		pci_read_config_dword(sp5100_tco_pci,
				      SP5100_PCI_WATCHDOG_MISC_REG,
				      &val);

		val |= SP5100_PCI_WATCHDOG_DECODE_EN;

		pci_write_config_dword(sp5100_tco_pci,
				       SP5100_PCI_WATCHDOG_MISC_REG,
				       val);

		/* Enable Watchdog timer and set the resolution to 1 sec */
		sp5100_tco_update_pm_reg8(SP5100_PM_WATCHDOG_CONTROL,
					  ~SP5100_PM_WATCHDOG_DISABLE,
					  SP5100_PM_WATCHDOG_SECOND_RES);
		break;
	case efch:
		/* Set the Watchdog timer resolution to 1 sec and enable */
		sp5100_tco_update_pm_reg8(EFCH_PM_DECODEEN3,
					  ~EFCH_PM_WATCHDOG_DISABLE,
					  EFCH_PM_DECODEEN_SECOND_RES);
		break;
	}
}

static u32 sp5100_tco_read_pm_reg32(u8 index)
{
	u32 val = 0;
	int i;

	for (i = 3; i >= 0; i--)
		val = (val << 8) + sp5100_tco_read_pm_reg8(index + i);

	return val;
}

static int sp5100_tco_setupdevice(struct device *dev,
				  struct watchdog_device *wdd)
{
	struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
	const char *dev_name;
	u32 mmio_addr = 0, val;
	int ret;

	/* Request the IO ports used by this driver */
	if (!request_muxed_region(SP5100_IO_PM_INDEX_REG,
				  SP5100_PM_IOPORTS_SIZE, "sp5100_tco")) {
		dev_err(dev, "I/O address 0x%04x already in use\n",
			SP5100_IO_PM_INDEX_REG);
		return -EBUSY;
	}

	/*
	 * Determine type of southbridge chipset.
	 */
	switch (tco->tco_reg_layout) {
	case sp5100:
		dev_name = SP5100_DEVNAME;
		mmio_addr = sp5100_tco_read_pm_reg32(SP5100_PM_WATCHDOG_BASE) &
								0xfffffff8;
		break;
	case sb800:
		dev_name = SB800_DEVNAME;
		mmio_addr = sp5100_tco_read_pm_reg32(SB800_PM_WATCHDOG_BASE) &
								0xfffffff8;
		break;
	case efch:
		dev_name = SB800_DEVNAME;
		val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
		if (val & EFCH_PM_DECODEEN_WDT_TMREN)
			mmio_addr = EFCH_PM_WDT_ADDR;
		break;
	default:
		return -ENODEV;
	}

	/* Check MMIO address conflict */
	if (!mmio_addr ||
	    !devm_request_mem_region(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE,
				     dev_name)) {
		if (mmio_addr)
			dev_dbg(dev, "MMIO address 0x%08x already in use\n",
				mmio_addr);
		switch (tco->tco_reg_layout) {
		case sp5100:
			/*
			 * Secondly, Find the watchdog timer MMIO address
			 * from SBResource_MMIO register.
			 */
			/* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
			pci_read_config_dword(sp5100_tco_pci,
					      SP5100_SB_RESOURCE_MMIO_BASE,
					      &mmio_addr);
			if ((mmio_addr & (SB800_ACPI_MMIO_DECODE_EN |
					  SB800_ACPI_MMIO_SEL)) !=
						  SB800_ACPI_MMIO_DECODE_EN) {
				ret = -ENODEV;
				goto unreg_region;
			}
			mmio_addr &= ~0xFFF;
			mmio_addr += SB800_PM_WDT_MMIO_OFFSET;
			break;
		case sb800:
			/* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
			mmio_addr =
				sp5100_tco_read_pm_reg32(SB800_PM_ACPI_MMIO_EN);
			if ((mmio_addr & (SB800_ACPI_MMIO_DECODE_EN |
					  SB800_ACPI_MMIO_SEL)) !=
						  SB800_ACPI_MMIO_DECODE_EN) {
				ret = -ENODEV;
				goto unreg_region;
			}
			mmio_addr &= ~0xFFF;
			mmio_addr += SB800_PM_WDT_MMIO_OFFSET;
			break;
		case efch:
			val = sp5100_tco_read_pm_reg8(EFCH_PM_ISACONTROL);
			if (!(val & EFCH_PM_ISACONTROL_MMIOEN)) {
				ret = -ENODEV;
				goto unreg_region;
			}
			mmio_addr = EFCH_PM_ACPI_MMIO_ADDR +
				    EFCH_PM_ACPI_MMIO_WDT_OFFSET;
			break;
		}
		dev_dbg(dev, "Got 0x%08x from SBResource_MMIO register\n",
			mmio_addr);
		if (!devm_request_mem_region(dev, mmio_addr,
					     SP5100_WDT_MEM_MAP_SIZE,
					     dev_name)) {
			dev_dbg(dev, "MMIO address 0x%08x already in use\n",
				mmio_addr);
			ret = -EBUSY;
			goto unreg_region;
		}
	}

	tco->tcobase = devm_ioremap(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE);
	if (!tco->tcobase) {
		dev_err(dev, "failed to get tcobase address\n");
		ret = -ENOMEM;
		goto unreg_region;
	}

	dev_info(dev, "Using 0x%08x for watchdog MMIO address\n", mmio_addr);

	/* Setup the watchdog timer */
	tco_timer_enable(tco);

	val = readl(SP5100_WDT_CONTROL(tco->tcobase));
	if (val & SP5100_WDT_DISABLED) {
		dev_err(dev, "Watchdog hardware is disabled\n");
		ret = -ENODEV;
		goto unreg_region;
	}

	/*
	 * Save WatchDogFired status, because WatchDogFired flag is
	 * cleared here.
	 */
	if (val & SP5100_WDT_FIRED)
		wdd->bootstatus = WDIOF_CARDRESET;
	/* Set watchdog action to reset the system */
	val &= ~SP5100_WDT_ACTION_RESET;
	writel(val, SP5100_WDT_CONTROL(tco->tcobase));

	/* Set a reasonable heartbeat before we stop the timer */
	tco_timer_set_timeout(wdd, wdd->timeout);

	/*
	 * Stop the TCO before we change anything so we don't race with
	 * a zeroed timer.
	 */
	tco_timer_stop(wdd);

	release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);

	return 0;

unreg_region:
	release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
	return ret;
}

static struct watchdog_info sp5100_tco_wdt_info = {
	.identity = "SP5100 TCO timer",
	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};

static const struct watchdog_ops sp5100_tco_wdt_ops = {
	.owner = THIS_MODULE,
	.start = tco_timer_start,
	.stop = tco_timer_stop,
	.ping = tco_timer_ping,
	.set_timeout = tco_timer_set_timeout,
};

static int sp5100_tco_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct watchdog_device *wdd;
	struct sp5100_tco *tco;
	int ret;

	tco = devm_kzalloc(dev, sizeof(*tco), GFP_KERNEL);
	if (!tco)
		return -ENOMEM;

	tco->tco_reg_layout = tco_reg_layout(sp5100_tco_pci);

	wdd = &tco->wdd;
	wdd->parent = dev;
	wdd->info = &sp5100_tco_wdt_info;
	wdd->ops = &sp5100_tco_wdt_ops;
	wdd->timeout = WATCHDOG_HEARTBEAT;
	wdd->min_timeout = 1;
	wdd->max_timeout = 0xffff;

	watchdog_init_timeout(wdd, heartbeat, NULL);
	watchdog_set_nowayout(wdd, nowayout);
	watchdog_stop_on_reboot(wdd);
	watchdog_stop_on_unregister(wdd);
	watchdog_set_drvdata(wdd, tco);

	ret = sp5100_tco_setupdevice(dev, wdd);
	if (ret)
		return ret;

	ret = devm_watchdog_register_device(dev, wdd);
	if (ret)
		return ret;

	/* Show module parameters */
	dev_info(dev, "initialized. heartbeat=%d sec (nowayout=%d)\n",
		 wdd->timeout, nowayout);

	return 0;
}

static struct platform_driver sp5100_tco_driver = {
	.probe		= sp5100_tco_probe,
	.driver		= {
		.name	= TCO_DRIVER_NAME,
	},
};

/*
 * Data for PCI driver interface
 *
 * This data only exists for exporting the supported
 * PCI ids via MODULE_DEVICE_TABLE.  We do not actually
 * register a pci_driver, because someone else might
 * want to register another driver on the same PCI id.
 */
static const struct pci_device_id sp5100_tco_pci_tbl[] = {
	{ PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID,
	  PCI_ANY_ID, },
	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS, PCI_ANY_ID,
	  PCI_ANY_ID, },
	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS, PCI_ANY_ID,
	  PCI_ANY_ID, },
	{ 0, },			/* End of list */
};
MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);

static int __init sp5100_tco_init(void)
{
	struct pci_dev *dev = NULL;
	int err;

	/* Match the PCI device */
	for_each_pci_dev(dev) {
		if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) {
			sp5100_tco_pci = dev;
			break;
		}
	}

	if (!sp5100_tco_pci)
		return -ENODEV;

	pr_info("SP5100/SB800 TCO WatchDog Timer Driver\n");

	err = platform_driver_register(&sp5100_tco_driver);
	if (err)
		return err;

	sp5100_tco_platform_device =
		platform_device_register_simple(TCO_DRIVER_NAME, -1, NULL, 0);
	if (IS_ERR(sp5100_tco_platform_device)) {
		err = PTR_ERR(sp5100_tco_platform_device);
		goto unreg_platform_driver;
	}

	return 0;

unreg_platform_driver:
	platform_driver_unregister(&sp5100_tco_driver);
	return err;
}

static void __exit sp5100_tco_exit(void)
{
	platform_device_unregister(sp5100_tco_platform_device);
	platform_driver_unregister(&sp5100_tco_driver);
}

module_init(sp5100_tco_init);
module_exit(sp5100_tco_exit);

MODULE_AUTHOR("Priyanka Gupta");
MODULE_DESCRIPTION("TCO timer driver for SP5100/SB800 chipset");
MODULE_LICENSE("GPL");