1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * sp5100_tco : TCO timer driver for sp5100 chipsets
5 * (c) Copyright 2009 Google Inc., All Rights Reserved.
8 * (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
10 * https://www.kernelconcepts.de
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
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
24 * AMD Publication 55772-A1-PUB "Processor Programming Reference (PPR)
25 * for AMD Family 17h Model 20h, Revision A1
30 * Includes, defines, variables, module parameters, ...
33 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35 #include <linux/init.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>
45 #include "sp5100_tco.h"
47 #define TCO_DRIVER_NAME "sp5100-tco"
49 /* internal variables */
52 sp5100, sb800, efch, efch_mmio
56 struct watchdog_device wdd;
57 void __iomem *tcobase;
58 enum tco_reg_layout tco_reg_layout;
61 /* the watchdog platform device */
62 static struct platform_device *sp5100_tco_platform_device;
63 /* the associated PCI device */
64 static struct pci_dev *sp5100_tco_pci;
66 /* module parameters */
68 #define WATCHDOG_ACTION 0
69 static bool action = WATCHDOG_ACTION;
70 module_param(action, bool, 0);
71 MODULE_PARM_DESC(action, "Action taken when watchdog expires, 0 to reset, 1 to poweroff (default="
72 __MODULE_STRING(WATCHDOG_ACTION) ")");
74 #define WATCHDOG_HEARTBEAT 60 /* 60 sec default heartbeat. */
75 static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
76 module_param(heartbeat, int, 0);
77 MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
78 __MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
80 static bool nowayout = WATCHDOG_NOWAYOUT;
81 module_param(nowayout, bool, 0);
82 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started."
83 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
86 * Some TCO specific functions
89 static enum tco_reg_layout tco_reg_layout(struct pci_dev *dev)
91 if (dev->vendor == PCI_VENDOR_ID_ATI &&
92 dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
93 dev->revision < 0x40) {
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) {
99 } else if (dev->vendor == PCI_VENDOR_ID_AMD &&
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))) {
109 static int tco_timer_start(struct watchdog_device *wdd)
111 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
114 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
115 val |= SP5100_WDT_START_STOP_BIT;
116 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
118 /* This must be a distinct write. */
119 val |= SP5100_WDT_TRIGGER_BIT;
120 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
125 static int tco_timer_stop(struct watchdog_device *wdd)
127 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
130 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
131 val &= ~SP5100_WDT_START_STOP_BIT;
132 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
137 static int tco_timer_ping(struct watchdog_device *wdd)
139 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
142 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
143 val |= SP5100_WDT_TRIGGER_BIT;
144 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
149 static int tco_timer_set_timeout(struct watchdog_device *wdd,
152 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
154 /* Write new heartbeat to watchdog */
155 writel(t, SP5100_WDT_COUNT(tco->tcobase));
162 static unsigned int tco_timer_get_timeleft(struct watchdog_device *wdd)
164 struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
166 return readl(SP5100_WDT_COUNT(tco->tcobase));
169 static u8 sp5100_tco_read_pm_reg8(u8 index)
171 outb(index, SP5100_IO_PM_INDEX_REG);
172 return inb(SP5100_IO_PM_DATA_REG);
175 static void sp5100_tco_update_pm_reg8(u8 index, u8 reset, u8 set)
179 outb(index, SP5100_IO_PM_INDEX_REG);
180 val = inb(SP5100_IO_PM_DATA_REG);
183 outb(val, SP5100_IO_PM_DATA_REG);
186 static void tco_timer_enable(struct sp5100_tco *tco)
190 switch (tco->tco_reg_layout) {
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);
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);
203 /* For SP5100 or SB7x0 */
204 /* Enable watchdog decode bit */
205 pci_read_config_dword(sp5100_tco_pci,
206 SP5100_PCI_WATCHDOG_MISC_REG,
209 val |= SP5100_PCI_WATCHDOG_DECODE_EN;
211 pci_write_config_dword(sp5100_tco_pci,
212 SP5100_PCI_WATCHDOG_MISC_REG,
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);
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);
231 static u32 sp5100_tco_read_pm_reg32(u8 index)
236 for (i = 3; i >= 0; i--)
237 val = (val << 8) + sp5100_tco_read_pm_reg8(index + i);
242 static u32 sp5100_tco_request_region(struct device *dev,
244 const char *dev_name)
246 if (!devm_request_mem_region(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE,
248 dev_dbg(dev, "MMIO address 0x%08x already in use\n", mmio_addr);
255 static u32 sp5100_tco_prepare_base(struct sp5100_tco *tco,
258 const char *dev_name)
260 struct device *dev = tco->wdd.parent;
262 dev_dbg(dev, "Got 0x%08x from SBResource_MMIO register\n", mmio_addr);
264 if (!mmio_addr && !alt_mmio_addr)
267 /* Check for MMIO address and alternate MMIO address conflicts */
269 mmio_addr = sp5100_tco_request_region(dev, mmio_addr, dev_name);
271 if (!mmio_addr && alt_mmio_addr)
272 mmio_addr = sp5100_tco_request_region(dev, alt_mmio_addr, dev_name);
275 dev_err(dev, "Failed to reserve MMIO or alternate MMIO region\n");
279 tco->tcobase = devm_ioremap(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE);
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);
286 dev_info(dev, "Using 0x%08x for watchdog MMIO address\n", mmio_addr);
291 static int sp5100_tco_timer_init(struct sp5100_tco *tco)
293 struct watchdog_device *wdd = &tco->wdd;
294 struct device *dev = wdd->parent;
297 val = readl(SP5100_WDT_CONTROL(tco->tcobase));
298 if (val & SP5100_WDT_DISABLED) {
299 dev_err(dev, "Watchdog hardware is disabled\n");
304 * Save WatchDogFired status, because WatchDogFired flag is
307 if (val & SP5100_WDT_FIRED)
308 wdd->bootstatus = WDIOF_CARDRESET;
310 /* Set watchdog action */
312 val |= SP5100_WDT_ACTION_RESET;
314 val &= ~SP5100_WDT_ACTION_RESET;
315 writel(val, SP5100_WDT_CONTROL(tco->tcobase));
317 /* Set a reasonable heartbeat before we stop the timer */
318 tco_timer_set_timeout(wdd, wdd->timeout);
321 * Stop the TCO before we change anything so we don't race with
329 static u8 efch_read_pm_reg8(void __iomem *addr, u8 index)
331 return readb(addr + index);
334 static void efch_update_pm_reg8(void __iomem *addr, u8 index, u8 reset, u8 set)
338 val = readb(addr + index);
341 writeb(val, addr + index);
344 static void tco_timer_enable_mmio(void __iomem *addr)
346 efch_update_pm_reg8(addr, EFCH_PM_DECODEEN3,
347 ~EFCH_PM_WATCHDOG_DISABLE,
348 EFCH_PM_DECODEEN_SECOND_RES);
351 static int sp5100_tco_setupdevice_mmio(struct device *dev,
352 struct watchdog_device *wdd)
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;
362 res = request_mem_region_muxed(EFCH_PM_ACPI_MMIO_PM_ADDR,
363 EFCH_PM_ACPI_MMIO_PM_SIZE,
368 "Memory region 0x%08x already in use\n",
369 EFCH_PM_ACPI_MMIO_PM_ADDR);
373 addr = ioremap(EFCH_PM_ACPI_MMIO_PM_ADDR, EFCH_PM_ACPI_MMIO_PM_SIZE);
375 dev_err(dev, "Address mapping failed\n");
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.
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);
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");
399 mmio_addr = EFCH_PM_WDT_ADDR;
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;
407 ret = sp5100_tco_prepare_base(tco, mmio_addr, alt_mmio_addr, dev_name);
409 tco_timer_enable_mmio(addr);
410 ret = sp5100_tco_timer_init(tco);
417 release_resource(res);
423 static int sp5100_tco_setupdevice(struct device *dev,
424 struct watchdog_device *wdd)
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;
432 if (tco->tco_reg_layout == efch_mmio)
433 return sp5100_tco_setupdevice_mmio(dev, wdd);
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);
444 * Determine type of southbridge chipset.
446 switch (tco->tco_reg_layout) {
448 dev_name = SP5100_DEVNAME;
449 mmio_addr = sp5100_tco_read_pm_reg32(SP5100_PM_WATCHDOG_BASE) &
453 * Secondly, find the watchdog timer MMIO address
454 * from SBResource_MMIO register.
457 /* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
458 pci_read_config_dword(sp5100_tco_pci,
459 SP5100_SB_RESOURCE_MMIO_BASE,
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;
467 dev_name = SB800_DEVNAME;
468 mmio_addr = sp5100_tco_read_pm_reg32(SB800_PM_WATCHDOG_BASE) &
471 /* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
472 val = sp5100_tco_read_pm_reg32(SB800_PM_ACPI_MMIO_EN);
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;
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;
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;
493 ret = sp5100_tco_prepare_base(tco, mmio_addr, alt_mmio_addr, dev_name);
495 /* Setup the watchdog timer */
496 tco_timer_enable(tco);
497 ret = sp5100_tco_timer_init(tco);
500 release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
504 static struct watchdog_info sp5100_tco_wdt_info = {
505 .identity = "SP5100 TCO timer",
506 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
509 static 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,
518 static int sp5100_tco_probe(struct platform_device *pdev)
520 struct device *dev = &pdev->dev;
521 struct watchdog_device *wdd;
522 struct sp5100_tco *tco;
525 tco = devm_kzalloc(dev, sizeof(*tco), GFP_KERNEL);
529 tco->tco_reg_layout = tco_reg_layout(sp5100_tco_pci);
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;
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);
545 ret = sp5100_tco_setupdevice(dev, wdd);
549 ret = devm_watchdog_register_device(dev, wdd);
553 /* Show module parameters */
554 dev_info(dev, "initialized. heartbeat=%d sec (nowayout=%d)\n",
555 wdd->timeout, nowayout);
560 static struct platform_driver sp5100_tco_driver = {
561 .probe = sp5100_tco_probe,
563 .name = TCO_DRIVER_NAME,
568 * Data for PCI driver interface
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.
575 static const struct pci_device_id sp5100_tco_pci_tbl[] = {
576 { PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID,
578 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS, PCI_ANY_ID,
580 { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS, PCI_ANY_ID,
582 { 0, }, /* End of list */
584 MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);
586 static int __init sp5100_tco_init(void)
588 struct pci_dev *dev = NULL;
591 /* Match the PCI device */
592 for_each_pci_dev(dev) {
593 if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) {
594 sp5100_tco_pci = dev;
602 pr_info("SP5100/SB800 TCO WatchDog Timer Driver\n");
604 err = platform_driver_register(&sp5100_tco_driver);
608 sp5100_tco_platform_device =
609 platform_device_register_simple(TCO_DRIVER_NAME, -1, NULL, 0);
610 if (IS_ERR(sp5100_tco_platform_device)) {
611 err = PTR_ERR(sp5100_tco_platform_device);
612 goto unreg_platform_driver;
617 unreg_platform_driver:
618 platform_driver_unregister(&sp5100_tco_driver);
622 static void __exit sp5100_tco_exit(void)
624 platform_device_unregister(sp5100_tco_platform_device);
625 platform_driver_unregister(&sp5100_tco_driver);
628 module_init(sp5100_tco_init);
629 module_exit(sp5100_tco_exit);
631 MODULE_AUTHOR("Priyanka Gupta");
632 MODULE_DESCRIPTION("TCO timer driver for SP5100/SB800 chipset");
633 MODULE_LICENSE("GPL");