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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * sp5100_tco : TCO timer driver for sp5100 chipsets
4 *
5 * (c) Copyright 2009 Google Inc., All Rights Reserved.
6 *
7 * Based on i8xx_tco.c:
8 * (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
9 * Reserved.
10 * https://www.kernelconcepts.de
11 *
12 * See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide",
13 * AMD Publication 44413 "AMD SP5100 Register Reference Guide"
14 * AMD Publication 45482 "AMD SB800-Series Southbridges Register
15 * Reference Guide"
16 * AMD Publication 48751 "BIOS and Kernel Developer’s Guide (BKDG)
17 * for AMD Family 16h Models 00h-0Fh Processors"
18 * AMD Publication 51192 "AMD Bolton FCH Register Reference Guide"
19 * AMD Publication 52740 "BIOS and Kernel Developer’s Guide (BKDG)
20 * for AMD Family 16h Models 30h-3Fh Processors"
21 * AMD Publication 55570-B1-PUB "Processor Programming Reference (PPR)
22 * for AMD Family 17h Model 18h, Revision B1
23 * Processors (PUB)
24 * AMD Publication 55772-A1-PUB "Processor Programming Reference (PPR)
25 * for AMD Family 17h Model 20h, Revision A1
26 * Processors (PUB)
27 */
28
29/*
30 * Includes, defines, variables, module parameters, ...
31 */
32
33#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
34
35#include <linux/init.h>
36#include <linux/io.h>
37#include <linux/ioport.h>
38#include <linux/module.h>
39#include <linux/moduleparam.h>
40#include <linux/pci.h>
41#include <linux/platform_device.h>
42#include <linux/types.h>
43#include <linux/watchdog.h>
44
45#include "sp5100_tco.h"
46
47#define TCO_DRIVER_NAME "sp5100-tco"
48
49/* internal variables */
50
51enum tco_reg_layout {
52 sp5100, sb800, efch, efch_mmio
53};
54
55struct sp5100_tco {
56 struct watchdog_device wdd;
57 void __iomem *tcobase;
58 enum tco_reg_layout tco_reg_layout;
59};
60
61/* the watchdog platform device */
62static struct platform_device *sp5100_tco_platform_device;
63/* the associated PCI device */
64static struct pci_dev *sp5100_tco_pci;
65
66/* module parameters */
67
68#define WATCHDOG_ACTION 0
69static bool action = WATCHDOG_ACTION;
70module_param(action, bool, 0);
71MODULE_PARM_DESC(action, "Action taken when watchdog expires, 0 to reset, 1 to poweroff (default="
72 __MODULE_STRING(WATCHDOG_ACTION) ")");
73
74#define WATCHDOG_HEARTBEAT 60 /* 60 sec default heartbeat. */
75static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
76module_param(heartbeat, int, 0);
77MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
78 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
79
80static bool nowayout = WATCHDOG_NOWAYOUT;
81module_param(nowayout, bool, 0);
82MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started."
83 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
84
85/*
86 * Some TCO specific functions
87 */
88
89static enum tco_reg_layout tco_reg_layout(struct pci_dev *dev)
90{
91 if (dev->vendor == PCI_VENDOR_ID_ATI &&
92 dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
93 dev->revision < 0x40) {
94 return sp5100;
95 } else if (dev->vendor == PCI_VENDOR_ID_AMD &&
96 sp5100_tco_pci->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
97 sp5100_tco_pci->revision >= AMD_ZEN_SMBUS_PCI_REV) {
98 return efch_mmio;
99 } else if ((dev->vendor == PCI_VENDOR_ID_AMD || dev->vendor == PCI_VENDOR_ID_HYGON) &&
100 ((dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
101 dev->revision >= 0x41) ||
102 (dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
103 dev->revision >= 0x49))) {
104 return efch;
105 }
106 return sb800;
107}
108
109static int tco_timer_start(struct watchdog_device *wdd)
110{
111 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
112 u32 val;
113
114 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
115 val |= SP5100_WDT_START_STOP_BIT;
116 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
117
118 /* This must be a distinct write. */
119 val |= SP5100_WDT_TRIGGER_BIT;
120 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
121
122 return 0;
123}
124
125static int tco_timer_stop(struct watchdog_device *wdd)
126{
127 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
128 u32 val;
129
130 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
131 val &= ~SP5100_WDT_START_STOP_BIT;
132 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
133
134 return 0;
135}
136
137static int tco_timer_ping(struct watchdog_device *wdd)
138{
139 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
140 u32 val;
141
142 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
143 val |= SP5100_WDT_TRIGGER_BIT;
144 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
145
146 return 0;
147}
148
149static int tco_timer_set_timeout(struct watchdog_device *wdd,
150 unsigned int t)
151{
152 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
153
154 /* Write new heartbeat to watchdog */
155 writel(t, SP5100_WDT_COUNT(tco->tcobase));
156
157 wdd->timeout = t;
158
159 return 0;
160}
161
162static unsigned int tco_timer_get_timeleft(struct watchdog_device *wdd)
163{
164 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
165
166 return readl(SP5100_WDT_COUNT(tco->tcobase));
167}
168
169static u8 sp5100_tco_read_pm_reg8(u8 index)
170{
171 outb(index, SP5100_IO_PM_INDEX_REG);
172 return inb(SP5100_IO_PM_DATA_REG);
173}
174
175static void sp5100_tco_update_pm_reg8(u8 index, u8 reset, u8 set)
176{
177 u8 val;
178
179 outb(index, SP5100_IO_PM_INDEX_REG);
180 val = inb(SP5100_IO_PM_DATA_REG);
181 val &= reset;
182 val |= set;
183 outb(val, SP5100_IO_PM_DATA_REG);
184}
185
186static void tco_timer_enable(struct sp5100_tco *tco)
187{
188 u32 val;
189
190 switch (tco->tco_reg_layout) {
191 case sb800:
192 /* For SB800 or later */
193 /* Set the Watchdog timer resolution to 1 sec */
194 sp5100_tco_update_pm_reg8(SB800_PM_WATCHDOG_CONFIG,
195 0xff, SB800_PM_WATCHDOG_SECOND_RES);
196
197 /* Enable watchdog decode bit and watchdog timer */
198 sp5100_tco_update_pm_reg8(SB800_PM_WATCHDOG_CONTROL,
199 ~SB800_PM_WATCHDOG_DISABLE,
200 SB800_PCI_WATCHDOG_DECODE_EN);
201 break;
202 case sp5100:
203 /* For SP5100 or SB7x0 */
204 /* Enable watchdog decode bit */
205 pci_read_config_dword(sp5100_tco_pci,
206 SP5100_PCI_WATCHDOG_MISC_REG,
207 &val);
208
209 val |= SP5100_PCI_WATCHDOG_DECODE_EN;
210
211 pci_write_config_dword(sp5100_tco_pci,
212 SP5100_PCI_WATCHDOG_MISC_REG,
213 val);
214
215 /* Enable Watchdog timer and set the resolution to 1 sec */
216 sp5100_tco_update_pm_reg8(SP5100_PM_WATCHDOG_CONTROL,
217 ~SP5100_PM_WATCHDOG_DISABLE,
218 SP5100_PM_WATCHDOG_SECOND_RES);
219 break;
220 case efch:
221 /* Set the Watchdog timer resolution to 1 sec and enable */
222 sp5100_tco_update_pm_reg8(EFCH_PM_DECODEEN3,
223 ~EFCH_PM_WATCHDOG_DISABLE,
224 EFCH_PM_DECODEEN_SECOND_RES);
225 break;
226 default:
227 break;
228 }
229}
230
231static u32 sp5100_tco_read_pm_reg32(u8 index)
232{
233 u32 val = 0;
234 int i;
235
236 for (i = 3; i >= 0; i--)
237 val = (val << 8) + sp5100_tco_read_pm_reg8(index + i);
238
239 return val;
240}
241
242static u32 sp5100_tco_request_region(struct device *dev,
243 u32 mmio_addr,
244 const char *dev_name)
245{
246 if (!devm_request_mem_region(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE,
247 dev_name)) {
248 dev_dbg(dev, "MMIO address 0x%08x already in use\n", mmio_addr);
249 return 0;
250 }
251
252 return mmio_addr;
253}
254
255static u32 sp5100_tco_prepare_base(struct sp5100_tco *tco,
256 u32 mmio_addr,
257 u32 alt_mmio_addr,
258 const char *dev_name)
259{
260 struct device *dev = tco->wdd.parent;
261
262 dev_dbg(dev, "Got 0x%08x from SBResource_MMIO register\n", mmio_addr);
263
264 if (!mmio_addr && !alt_mmio_addr)
265 return -ENODEV;
266
267 /* Check for MMIO address and alternate MMIO address conflicts */
268 if (mmio_addr)
269 mmio_addr = sp5100_tco_request_region(dev, mmio_addr, dev_name);
270
271 if (!mmio_addr && alt_mmio_addr)
272 mmio_addr = sp5100_tco_request_region(dev, alt_mmio_addr, dev_name);
273
274 if (!mmio_addr) {
275 dev_err(dev, "Failed to reserve MMIO or alternate MMIO region\n");
276 return -EBUSY;
277 }
278
279 tco->tcobase = devm_ioremap(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE);
280 if (!tco->tcobase) {
281 dev_err(dev, "MMIO address 0x%08x failed mapping\n", mmio_addr);
282 devm_release_mem_region(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE);
283 return -ENOMEM;
284 }
285
286 dev_info(dev, "Using 0x%08x for watchdog MMIO address\n", mmio_addr);
287
288 return 0;
289}
290
291static int sp5100_tco_timer_init(struct sp5100_tco *tco)
292{
293 struct watchdog_device *wdd = &tco->wdd;
294 struct device *dev = wdd->parent;
295 u32 val;
296
297 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
298 if (val & SP5100_WDT_DISABLED) {
299 dev_err(dev, "Watchdog hardware is disabled\n");
300 return -ENODEV;
301 }
302
303 /*
304 * Save WatchDogFired status, because WatchDogFired flag is
305 * cleared here.
306 */
307 if (val & SP5100_WDT_FIRED)
308 wdd->bootstatus = WDIOF_CARDRESET;
309
310 /* Set watchdog action */
311 if (action)
312 val |= SP5100_WDT_ACTION_RESET;
313 else
314 val &= ~SP5100_WDT_ACTION_RESET;
315 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
316
317 /* Set a reasonable heartbeat before we stop the timer */
318 tco_timer_set_timeout(wdd, wdd->timeout);
319
320 /*
321 * Stop the TCO before we change anything so we don't race with
322 * a zeroed timer.
323 */
324 tco_timer_stop(wdd);
325
326 return 0;
327}
328
329static u8 efch_read_pm_reg8(void __iomem *addr, u8 index)
330{
331 return readb(addr + index);
332}
333
334static void efch_update_pm_reg8(void __iomem *addr, u8 index, u8 reset, u8 set)
335{
336 u8 val;
337
338 val = readb(addr + index);
339 val &= reset;
340 val |= set;
341 writeb(val, addr + index);
342}
343
344static void tco_timer_enable_mmio(void __iomem *addr)
345{
346 efch_update_pm_reg8(addr, EFCH_PM_DECODEEN3,
347 ~EFCH_PM_WATCHDOG_DISABLE,
348 EFCH_PM_DECODEEN_SECOND_RES);
349}
350
351static int sp5100_tco_setupdevice_mmio(struct device *dev,
352 struct watchdog_device *wdd)
353{
354 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
355 const char *dev_name = SB800_DEVNAME;
356 u32 mmio_addr = 0, alt_mmio_addr = 0;
357 struct resource *res;
358 void __iomem *addr;
359 int ret;
360 u32 val;
361
362 res = request_mem_region_muxed(EFCH_PM_ACPI_MMIO_PM_ADDR,
363 EFCH_PM_ACPI_MMIO_PM_SIZE,
364 "sp5100_tco");
365
366 if (!res) {
367 dev_err(dev,
368 "Memory region 0x%08x already in use\n",
369 EFCH_PM_ACPI_MMIO_PM_ADDR);
370 return -EBUSY;
371 }
372
373 addr = ioremap(EFCH_PM_ACPI_MMIO_PM_ADDR, EFCH_PM_ACPI_MMIO_PM_SIZE);
374 if (!addr) {
375 dev_err(dev, "Address mapping failed\n");
376 ret = -ENOMEM;
377 goto out;
378 }
379
380 /*
381 * EFCH_PM_DECODEEN_WDT_TMREN is dual purpose. This bitfield
382 * enables sp5100_tco register MMIO space decoding. The bitfield
383 * also starts the timer operation. Enable if not already enabled.
384 */
385 val = efch_read_pm_reg8(addr, EFCH_PM_DECODEEN);
386 if (!(val & EFCH_PM_DECODEEN_WDT_TMREN)) {
387 efch_update_pm_reg8(addr, EFCH_PM_DECODEEN, 0xff,
388 EFCH_PM_DECODEEN_WDT_TMREN);
389 }
390
391 /* Error if the timer could not be enabled */
392 val = efch_read_pm_reg8(addr, EFCH_PM_DECODEEN);
393 if (!(val & EFCH_PM_DECODEEN_WDT_TMREN)) {
394 dev_err(dev, "Failed to enable the timer\n");
395 ret = -EFAULT;
396 goto out;
397 }
398
399 mmio_addr = EFCH_PM_WDT_ADDR;
400
401 /* Determine alternate MMIO base address */
402 val = efch_read_pm_reg8(addr, EFCH_PM_ISACONTROL);
403 if (val & EFCH_PM_ISACONTROL_MMIOEN)
404 alt_mmio_addr = EFCH_PM_ACPI_MMIO_ADDR +
405 EFCH_PM_ACPI_MMIO_WDT_OFFSET;
406
407 ret = sp5100_tco_prepare_base(tco, mmio_addr, alt_mmio_addr, dev_name);
408 if (!ret) {
409 tco_timer_enable_mmio(addr);
410 ret = sp5100_tco_timer_init(tco);
411 }
412
413out:
414 if (addr)
415 iounmap(addr);
416
417 release_resource(res);
418 kfree(res);
419
420 return ret;
421}
422
423static int sp5100_tco_setupdevice(struct device *dev,
424 struct watchdog_device *wdd)
425{
426 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
427 const char *dev_name;
428 u32 mmio_addr = 0, val;
429 u32 alt_mmio_addr = 0;
430 int ret;
431
432 if (tco->tco_reg_layout == efch_mmio)
433 return sp5100_tco_setupdevice_mmio(dev, wdd);
434
435 /* Request the IO ports used by this driver */
436 if (!request_muxed_region(SP5100_IO_PM_INDEX_REG,
437 SP5100_PM_IOPORTS_SIZE, "sp5100_tco")) {
438 dev_err(dev, "I/O address 0x%04x already in use\n",
439 SP5100_IO_PM_INDEX_REG);
440 return -EBUSY;
441 }
442
443 /*
444 * Determine type of southbridge chipset.
445 */
446 switch (tco->tco_reg_layout) {
447 case sp5100:
448 dev_name = SP5100_DEVNAME;
449 mmio_addr = sp5100_tco_read_pm_reg32(SP5100_PM_WATCHDOG_BASE) &
450 0xfffffff8;
451
452 /*
453 * Secondly, find the watchdog timer MMIO address
454 * from SBResource_MMIO register.
455 */
456
457 /* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
458 pci_read_config_dword(sp5100_tco_pci,
459 SP5100_SB_RESOURCE_MMIO_BASE,
460 &val);
461
462 /* Verify MMIO is enabled and using bar0 */
463 if ((val & SB800_ACPI_MMIO_MASK) == SB800_ACPI_MMIO_DECODE_EN)
464 alt_mmio_addr = (val & ~0xfff) + SB800_PM_WDT_MMIO_OFFSET;
465 break;
466 case sb800:
467 dev_name = SB800_DEVNAME;
468 mmio_addr = sp5100_tco_read_pm_reg32(SB800_PM_WATCHDOG_BASE) &
469 0xfffffff8;
470
471 /* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
472 val = sp5100_tco_read_pm_reg32(SB800_PM_ACPI_MMIO_EN);
473
474 /* Verify MMIO is enabled and using bar0 */
475 if ((val & SB800_ACPI_MMIO_MASK) == SB800_ACPI_MMIO_DECODE_EN)
476 alt_mmio_addr = (val & ~0xfff) + SB800_PM_WDT_MMIO_OFFSET;
477 break;
478 case efch:
479 dev_name = SB800_DEVNAME;
480 val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
481 if (val & EFCH_PM_DECODEEN_WDT_TMREN)
482 mmio_addr = EFCH_PM_WDT_ADDR;
483
484 val = sp5100_tco_read_pm_reg8(EFCH_PM_ISACONTROL);
485 if (val & EFCH_PM_ISACONTROL_MMIOEN)
486 alt_mmio_addr = EFCH_PM_ACPI_MMIO_ADDR +
487 EFCH_PM_ACPI_MMIO_WDT_OFFSET;
488 break;
489 default:
490 return -ENODEV;
491 }
492
493 ret = sp5100_tco_prepare_base(tco, mmio_addr, alt_mmio_addr, dev_name);
494 if (!ret) {
495 /* Setup the watchdog timer */
496 tco_timer_enable(tco);
497 ret = sp5100_tco_timer_init(tco);
498 }
499
500 release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
501 return ret;
502}
503
504static struct watchdog_info sp5100_tco_wdt_info = {
505 .identity = "SP5100 TCO timer",
506 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
507};
508
509static const struct watchdog_ops sp5100_tco_wdt_ops = {
510 .owner = THIS_MODULE,
511 .start = tco_timer_start,
512 .stop = tco_timer_stop,
513 .ping = tco_timer_ping,
514 .set_timeout = tco_timer_set_timeout,
515 .get_timeleft = tco_timer_get_timeleft,
516};
517
518static int sp5100_tco_probe(struct platform_device *pdev)
519{
520 struct device *dev = &pdev->dev;
521 struct watchdog_device *wdd;
522 struct sp5100_tco *tco;
523 int ret;
524
525 tco = devm_kzalloc(dev, sizeof(*tco), GFP_KERNEL);
526 if (!tco)
527 return -ENOMEM;
528
529 tco->tco_reg_layout = tco_reg_layout(sp5100_tco_pci);
530
531 wdd = &tco->wdd;
532 wdd->parent = dev;
533 wdd->info = &sp5100_tco_wdt_info;
534 wdd->ops = &sp5100_tco_wdt_ops;
535 wdd->timeout = WATCHDOG_HEARTBEAT;
536 wdd->min_timeout = 1;
537 wdd->max_timeout = 0xffff;
538
539 watchdog_init_timeout(wdd, heartbeat, NULL);
540 watchdog_set_nowayout(wdd, nowayout);
541 watchdog_stop_on_reboot(wdd);
542 watchdog_stop_on_unregister(wdd);
543 watchdog_set_drvdata(wdd, tco);
544
545 ret = sp5100_tco_setupdevice(dev, wdd);
546 if (ret)
547 return ret;
548
549 ret = devm_watchdog_register_device(dev, wdd);
550 if (ret)
551 return ret;
552
553 /* Show module parameters */
554 dev_info(dev, "initialized. heartbeat=%d sec (nowayout=%d)\n",
555 wdd->timeout, nowayout);
556
557 return 0;
558}
559
560static struct platform_driver sp5100_tco_driver = {
561 .probe = sp5100_tco_probe,
562 .driver = {
563 .name = TCO_DRIVER_NAME,
564 },
565};
566
567/*
568 * Data for PCI driver interface
569 *
570 * This data only exists for exporting the supported
571 * PCI ids via MODULE_DEVICE_TABLE. We do not actually
572 * register a pci_driver, because someone else might
573 * want to register another driver on the same PCI id.
574 */
575static const struct pci_device_id sp5100_tco_pci_tbl[] = {
576 { PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID,
577 PCI_ANY_ID, },
578 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS, PCI_ANY_ID,
579 PCI_ANY_ID, },
580 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS, PCI_ANY_ID,
581 PCI_ANY_ID, },
582 { PCI_VENDOR_ID_HYGON, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS, PCI_ANY_ID,
583 PCI_ANY_ID, },
584 { 0, }, /* End of list */
585};
586MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);
587
588static int __init sp5100_tco_init(void)
589{
590 struct pci_dev *dev = NULL;
591 int err;
592
593 /* Match the PCI device */
594 for_each_pci_dev(dev) {
595 if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) {
596 sp5100_tco_pci = dev;
597 break;
598 }
599 }
600
601 if (!sp5100_tco_pci)
602 return -ENODEV;
603
604 pr_info("SP5100/SB800 TCO WatchDog Timer Driver\n");
605
606 err = platform_driver_register(&sp5100_tco_driver);
607 if (err)
608 return err;
609
610 sp5100_tco_platform_device =
611 platform_device_register_simple(TCO_DRIVER_NAME, -1, NULL, 0);
612 if (IS_ERR(sp5100_tco_platform_device)) {
613 err = PTR_ERR(sp5100_tco_platform_device);
614 goto unreg_platform_driver;
615 }
616
617 return 0;
618
619unreg_platform_driver:
620 platform_driver_unregister(&sp5100_tco_driver);
621 return err;
622}
623
624static void __exit sp5100_tco_exit(void)
625{
626 platform_device_unregister(sp5100_tco_platform_device);
627 platform_driver_unregister(&sp5100_tco_driver);
628}
629
630module_init(sp5100_tco_init);
631module_exit(sp5100_tco_exit);
632
633MODULE_AUTHOR("Priyanka Gupta");
634MODULE_DESCRIPTION("TCO timer driver for SP5100/SB800 chipset");
635MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * sp5100_tco : TCO timer driver for sp5100 chipsets
4 *
5 * (c) Copyright 2009 Google Inc., All Rights Reserved.
6 *
7 * Based on i8xx_tco.c:
8 * (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
9 * Reserved.
10 * https://www.kernelconcepts.de
11 *
12 * See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide",
13 * AMD Publication 45482 "AMD SB800-Series Southbridges Register
14 * Reference Guide"
15 * AMD Publication 48751 "BIOS and Kernel Developer’s Guide (BKDG)
16 * for AMD Family 16h Models 00h-0Fh Processors"
17 * AMD Publication 51192 "AMD Bolton FCH Register Reference Guide"
18 * AMD Publication 52740 "BIOS and Kernel Developer’s Guide (BKDG)
19 * for AMD Family 16h Models 30h-3Fh Processors"
20 */
21
22/*
23 * Includes, defines, variables, module parameters, ...
24 */
25
26#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27
28#include <linux/init.h>
29#include <linux/io.h>
30#include <linux/ioport.h>
31#include <linux/module.h>
32#include <linux/moduleparam.h>
33#include <linux/pci.h>
34#include <linux/platform_device.h>
35#include <linux/types.h>
36#include <linux/watchdog.h>
37
38#include "sp5100_tco.h"
39
40#define TCO_DRIVER_NAME "sp5100-tco"
41
42/* internal variables */
43
44enum tco_reg_layout {
45 sp5100, sb800, efch
46};
47
48struct sp5100_tco {
49 struct watchdog_device wdd;
50 void __iomem *tcobase;
51 enum tco_reg_layout tco_reg_layout;
52};
53
54/* the watchdog platform device */
55static struct platform_device *sp5100_tco_platform_device;
56/* the associated PCI device */
57static struct pci_dev *sp5100_tco_pci;
58
59/* module parameters */
60
61#define WATCHDOG_HEARTBEAT 60 /* 60 sec default heartbeat. */
62static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
63module_param(heartbeat, int, 0);
64MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
65 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
66
67static bool nowayout = WATCHDOG_NOWAYOUT;
68module_param(nowayout, bool, 0);
69MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started."
70 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
71
72/*
73 * Some TCO specific functions
74 */
75
76static enum tco_reg_layout tco_reg_layout(struct pci_dev *dev)
77{
78 if (dev->vendor == PCI_VENDOR_ID_ATI &&
79 dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
80 dev->revision < 0x40) {
81 return sp5100;
82 } else if (dev->vendor == PCI_VENDOR_ID_AMD &&
83 ((dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
84 dev->revision >= 0x41) ||
85 (dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
86 dev->revision >= 0x49))) {
87 return efch;
88 }
89 return sb800;
90}
91
92static int tco_timer_start(struct watchdog_device *wdd)
93{
94 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
95 u32 val;
96
97 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
98 val |= SP5100_WDT_START_STOP_BIT;
99 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
100
101 return 0;
102}
103
104static int tco_timer_stop(struct watchdog_device *wdd)
105{
106 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
107 u32 val;
108
109 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
110 val &= ~SP5100_WDT_START_STOP_BIT;
111 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
112
113 return 0;
114}
115
116static int tco_timer_ping(struct watchdog_device *wdd)
117{
118 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
119 u32 val;
120
121 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
122 val |= SP5100_WDT_TRIGGER_BIT;
123 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
124
125 return 0;
126}
127
128static int tco_timer_set_timeout(struct watchdog_device *wdd,
129 unsigned int t)
130{
131 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
132
133 /* Write new heartbeat to watchdog */
134 writel(t, SP5100_WDT_COUNT(tco->tcobase));
135
136 wdd->timeout = t;
137
138 return 0;
139}
140
141static u8 sp5100_tco_read_pm_reg8(u8 index)
142{
143 outb(index, SP5100_IO_PM_INDEX_REG);
144 return inb(SP5100_IO_PM_DATA_REG);
145}
146
147static void sp5100_tco_update_pm_reg8(u8 index, u8 reset, u8 set)
148{
149 u8 val;
150
151 outb(index, SP5100_IO_PM_INDEX_REG);
152 val = inb(SP5100_IO_PM_DATA_REG);
153 val &= reset;
154 val |= set;
155 outb(val, SP5100_IO_PM_DATA_REG);
156}
157
158static void tco_timer_enable(struct sp5100_tco *tco)
159{
160 u32 val;
161
162 switch (tco->tco_reg_layout) {
163 case sb800:
164 /* For SB800 or later */
165 /* Set the Watchdog timer resolution to 1 sec */
166 sp5100_tco_update_pm_reg8(SB800_PM_WATCHDOG_CONFIG,
167 0xff, SB800_PM_WATCHDOG_SECOND_RES);
168
169 /* Enable watchdog decode bit and watchdog timer */
170 sp5100_tco_update_pm_reg8(SB800_PM_WATCHDOG_CONTROL,
171 ~SB800_PM_WATCHDOG_DISABLE,
172 SB800_PCI_WATCHDOG_DECODE_EN);
173 break;
174 case sp5100:
175 /* For SP5100 or SB7x0 */
176 /* Enable watchdog decode bit */
177 pci_read_config_dword(sp5100_tco_pci,
178 SP5100_PCI_WATCHDOG_MISC_REG,
179 &val);
180
181 val |= SP5100_PCI_WATCHDOG_DECODE_EN;
182
183 pci_write_config_dword(sp5100_tco_pci,
184 SP5100_PCI_WATCHDOG_MISC_REG,
185 val);
186
187 /* Enable Watchdog timer and set the resolution to 1 sec */
188 sp5100_tco_update_pm_reg8(SP5100_PM_WATCHDOG_CONTROL,
189 ~SP5100_PM_WATCHDOG_DISABLE,
190 SP5100_PM_WATCHDOG_SECOND_RES);
191 break;
192 case efch:
193 /* Set the Watchdog timer resolution to 1 sec and enable */
194 sp5100_tco_update_pm_reg8(EFCH_PM_DECODEEN3,
195 ~EFCH_PM_WATCHDOG_DISABLE,
196 EFCH_PM_DECODEEN_SECOND_RES);
197 break;
198 }
199}
200
201static u32 sp5100_tco_read_pm_reg32(u8 index)
202{
203 u32 val = 0;
204 int i;
205
206 for (i = 3; i >= 0; i--)
207 val = (val << 8) + sp5100_tco_read_pm_reg8(index + i);
208
209 return val;
210}
211
212static int sp5100_tco_setupdevice(struct device *dev,
213 struct watchdog_device *wdd)
214{
215 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
216 const char *dev_name;
217 u32 mmio_addr = 0, val;
218 int ret;
219
220 /* Request the IO ports used by this driver */
221 if (!request_muxed_region(SP5100_IO_PM_INDEX_REG,
222 SP5100_PM_IOPORTS_SIZE, "sp5100_tco")) {
223 dev_err(dev, "I/O address 0x%04x already in use\n",
224 SP5100_IO_PM_INDEX_REG);
225 return -EBUSY;
226 }
227
228 /*
229 * Determine type of southbridge chipset.
230 */
231 switch (tco->tco_reg_layout) {
232 case sp5100:
233 dev_name = SP5100_DEVNAME;
234 mmio_addr = sp5100_tco_read_pm_reg32(SP5100_PM_WATCHDOG_BASE) &
235 0xfffffff8;
236 break;
237 case sb800:
238 dev_name = SB800_DEVNAME;
239 mmio_addr = sp5100_tco_read_pm_reg32(SB800_PM_WATCHDOG_BASE) &
240 0xfffffff8;
241 break;
242 case efch:
243 dev_name = SB800_DEVNAME;
244 val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
245 if (val & EFCH_PM_DECODEEN_WDT_TMREN)
246 mmio_addr = EFCH_PM_WDT_ADDR;
247 break;
248 default:
249 return -ENODEV;
250 }
251
252 /* Check MMIO address conflict */
253 if (!mmio_addr ||
254 !devm_request_mem_region(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE,
255 dev_name)) {
256 if (mmio_addr)
257 dev_dbg(dev, "MMIO address 0x%08x already in use\n",
258 mmio_addr);
259 switch (tco->tco_reg_layout) {
260 case sp5100:
261 /*
262 * Secondly, Find the watchdog timer MMIO address
263 * from SBResource_MMIO register.
264 */
265 /* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
266 pci_read_config_dword(sp5100_tco_pci,
267 SP5100_SB_RESOURCE_MMIO_BASE,
268 &mmio_addr);
269 if ((mmio_addr & (SB800_ACPI_MMIO_DECODE_EN |
270 SB800_ACPI_MMIO_SEL)) !=
271 SB800_ACPI_MMIO_DECODE_EN) {
272 ret = -ENODEV;
273 goto unreg_region;
274 }
275 mmio_addr &= ~0xFFF;
276 mmio_addr += SB800_PM_WDT_MMIO_OFFSET;
277 break;
278 case sb800:
279 /* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
280 mmio_addr =
281 sp5100_tco_read_pm_reg32(SB800_PM_ACPI_MMIO_EN);
282 if ((mmio_addr & (SB800_ACPI_MMIO_DECODE_EN |
283 SB800_ACPI_MMIO_SEL)) !=
284 SB800_ACPI_MMIO_DECODE_EN) {
285 ret = -ENODEV;
286 goto unreg_region;
287 }
288 mmio_addr &= ~0xFFF;
289 mmio_addr += SB800_PM_WDT_MMIO_OFFSET;
290 break;
291 case efch:
292 val = sp5100_tco_read_pm_reg8(EFCH_PM_ISACONTROL);
293 if (!(val & EFCH_PM_ISACONTROL_MMIOEN)) {
294 ret = -ENODEV;
295 goto unreg_region;
296 }
297 mmio_addr = EFCH_PM_ACPI_MMIO_ADDR +
298 EFCH_PM_ACPI_MMIO_WDT_OFFSET;
299 break;
300 }
301 dev_dbg(dev, "Got 0x%08x from SBResource_MMIO register\n",
302 mmio_addr);
303 if (!devm_request_mem_region(dev, mmio_addr,
304 SP5100_WDT_MEM_MAP_SIZE,
305 dev_name)) {
306 dev_dbg(dev, "MMIO address 0x%08x already in use\n",
307 mmio_addr);
308 ret = -EBUSY;
309 goto unreg_region;
310 }
311 }
312
313 tco->tcobase = devm_ioremap(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE);
314 if (!tco->tcobase) {
315 dev_err(dev, "failed to get tcobase address\n");
316 ret = -ENOMEM;
317 goto unreg_region;
318 }
319
320 dev_info(dev, "Using 0x%08x for watchdog MMIO address\n", mmio_addr);
321
322 /* Setup the watchdog timer */
323 tco_timer_enable(tco);
324
325 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
326 if (val & SP5100_WDT_DISABLED) {
327 dev_err(dev, "Watchdog hardware is disabled\n");
328 ret = -ENODEV;
329 goto unreg_region;
330 }
331
332 /*
333 * Save WatchDogFired status, because WatchDogFired flag is
334 * cleared here.
335 */
336 if (val & SP5100_WDT_FIRED)
337 wdd->bootstatus = WDIOF_CARDRESET;
338 /* Set watchdog action to reset the system */
339 val &= ~SP5100_WDT_ACTION_RESET;
340 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
341
342 /* Set a reasonable heartbeat before we stop the timer */
343 tco_timer_set_timeout(wdd, wdd->timeout);
344
345 /*
346 * Stop the TCO before we change anything so we don't race with
347 * a zeroed timer.
348 */
349 tco_timer_stop(wdd);
350
351 release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
352
353 return 0;
354
355unreg_region:
356 release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
357 return ret;
358}
359
360static struct watchdog_info sp5100_tco_wdt_info = {
361 .identity = "SP5100 TCO timer",
362 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
363};
364
365static const struct watchdog_ops sp5100_tco_wdt_ops = {
366 .owner = THIS_MODULE,
367 .start = tco_timer_start,
368 .stop = tco_timer_stop,
369 .ping = tco_timer_ping,
370 .set_timeout = tco_timer_set_timeout,
371};
372
373static int sp5100_tco_probe(struct platform_device *pdev)
374{
375 struct device *dev = &pdev->dev;
376 struct watchdog_device *wdd;
377 struct sp5100_tco *tco;
378 int ret;
379
380 tco = devm_kzalloc(dev, sizeof(*tco), GFP_KERNEL);
381 if (!tco)
382 return -ENOMEM;
383
384 tco->tco_reg_layout = tco_reg_layout(sp5100_tco_pci);
385
386 wdd = &tco->wdd;
387 wdd->parent = dev;
388 wdd->info = &sp5100_tco_wdt_info;
389 wdd->ops = &sp5100_tco_wdt_ops;
390 wdd->timeout = WATCHDOG_HEARTBEAT;
391 wdd->min_timeout = 1;
392 wdd->max_timeout = 0xffff;
393
394 watchdog_init_timeout(wdd, heartbeat, NULL);
395 watchdog_set_nowayout(wdd, nowayout);
396 watchdog_stop_on_reboot(wdd);
397 watchdog_stop_on_unregister(wdd);
398 watchdog_set_drvdata(wdd, tco);
399
400 ret = sp5100_tco_setupdevice(dev, wdd);
401 if (ret)
402 return ret;
403
404 ret = devm_watchdog_register_device(dev, wdd);
405 if (ret)
406 return ret;
407
408 /* Show module parameters */
409 dev_info(dev, "initialized. heartbeat=%d sec (nowayout=%d)\n",
410 wdd->timeout, nowayout);
411
412 return 0;
413}
414
415static struct platform_driver sp5100_tco_driver = {
416 .probe = sp5100_tco_probe,
417 .driver = {
418 .name = TCO_DRIVER_NAME,
419 },
420};
421
422/*
423 * Data for PCI driver interface
424 *
425 * This data only exists for exporting the supported
426 * PCI ids via MODULE_DEVICE_TABLE. We do not actually
427 * register a pci_driver, because someone else might
428 * want to register another driver on the same PCI id.
429 */
430static const struct pci_device_id sp5100_tco_pci_tbl[] = {
431 { PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID,
432 PCI_ANY_ID, },
433 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS, PCI_ANY_ID,
434 PCI_ANY_ID, },
435 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS, PCI_ANY_ID,
436 PCI_ANY_ID, },
437 { 0, }, /* End of list */
438};
439MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);
440
441static int __init sp5100_tco_init(void)
442{
443 struct pci_dev *dev = NULL;
444 int err;
445
446 /* Match the PCI device */
447 for_each_pci_dev(dev) {
448 if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) {
449 sp5100_tco_pci = dev;
450 break;
451 }
452 }
453
454 if (!sp5100_tco_pci)
455 return -ENODEV;
456
457 pr_info("SP5100/SB800 TCO WatchDog Timer Driver\n");
458
459 err = platform_driver_register(&sp5100_tco_driver);
460 if (err)
461 return err;
462
463 sp5100_tco_platform_device =
464 platform_device_register_simple(TCO_DRIVER_NAME, -1, NULL, 0);
465 if (IS_ERR(sp5100_tco_platform_device)) {
466 err = PTR_ERR(sp5100_tco_platform_device);
467 goto unreg_platform_driver;
468 }
469
470 return 0;
471
472unreg_platform_driver:
473 platform_driver_unregister(&sp5100_tco_driver);
474 return err;
475}
476
477static void __exit sp5100_tco_exit(void)
478{
479 platform_device_unregister(sp5100_tco_platform_device);
480 platform_driver_unregister(&sp5100_tco_driver);
481}
482
483module_init(sp5100_tco_init);
484module_exit(sp5100_tco_exit);
485
486MODULE_AUTHOR("Priyanka Gupta");
487MODULE_DESCRIPTION("TCO timer driver for SP5100/SB800 chipset");
488MODULE_LICENSE("GPL");