2 * sp5100_tco : TCO timer driver for sp5100 chipsets
4 * (c) Copyright 2009 Google Inc., All Rights Reserved.
7 * (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
9 * http://www.kernelconcepts.de
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
16 * See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide",
17 * AMD Publication 45482 "AMD SB800-Series Southbridges Register
22 * Includes, defines, variables, module parameters, ...
25 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/types.h>
30 #include <linux/miscdevice.h>
31 #include <linux/watchdog.h>
32 #include <linux/init.h>
34 #include <linux/pci.h>
35 #include <linux/ioport.h>
36 #include <linux/platform_device.h>
37 #include <linux/uaccess.h>
40 #include "sp5100_tco.h"
42 /* Module and version information */
43 #define TCO_VERSION "0.03"
44 #define TCO_MODULE_NAME "SP5100 TCO timer"
45 #define TCO_DRIVER_NAME TCO_MODULE_NAME ", v" TCO_VERSION
47 /* internal variables */
48 static u32 tcobase_phys
;
49 static u32 resbase_phys
;
50 static u32 tco_wdt_fired
;
51 static void __iomem
*tcobase
;
52 static unsigned int pm_iobase
;
53 static DEFINE_SPINLOCK(tco_lock
); /* Guards the hardware */
54 static unsigned long timer_alive
;
55 static char tco_expect_close
;
56 static struct pci_dev
*sp5100_tco_pci
;
57 static struct resource wdt_res
= {
58 .name
= "Watchdog Timer",
59 .flags
= IORESOURCE_MEM
,
62 /* the watchdog platform device */
63 static struct platform_device
*sp5100_tco_platform_device
;
65 /* module parameters */
67 #define WATCHDOG_HEARTBEAT 60 /* 60 sec default heartbeat. */
68 static int heartbeat
= WATCHDOG_HEARTBEAT
; /* in seconds */
69 module_param(heartbeat
, int, 0);
70 MODULE_PARM_DESC(heartbeat
, "Watchdog heartbeat in seconds. (default="
71 __MODULE_STRING(WATCHDOG_HEARTBEAT
) ")");
73 static bool nowayout
= WATCHDOG_NOWAYOUT
;
74 module_param(nowayout
, bool, 0);
75 MODULE_PARM_DESC(nowayout
, "Watchdog cannot be stopped once started."
76 " (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT
) ")");
78 static unsigned int force_addr
;
79 module_param(force_addr
, uint
, 0);
80 MODULE_PARM_DESC(force_addr
, "Force the use of specified MMIO address."
81 " ONLY USE THIS PARAMETER IF YOU REALLY KNOW"
82 " WHAT YOU ARE DOING (default=none)");
85 * Some TCO specific functions
87 static void tco_timer_start(void)
92 spin_lock_irqsave(&tco_lock
, flags
);
93 val
= readl(SP5100_WDT_CONTROL(tcobase
));
94 val
|= SP5100_WDT_START_STOP_BIT
;
95 writel(val
, SP5100_WDT_CONTROL(tcobase
));
96 spin_unlock_irqrestore(&tco_lock
, flags
);
99 static void tco_timer_stop(void)
104 spin_lock_irqsave(&tco_lock
, flags
);
105 val
= readl(SP5100_WDT_CONTROL(tcobase
));
106 val
&= ~SP5100_WDT_START_STOP_BIT
;
107 writel(val
, SP5100_WDT_CONTROL(tcobase
));
108 spin_unlock_irqrestore(&tco_lock
, flags
);
111 static void tco_timer_keepalive(void)
116 spin_lock_irqsave(&tco_lock
, flags
);
117 val
= readl(SP5100_WDT_CONTROL(tcobase
));
118 val
|= SP5100_WDT_TRIGGER_BIT
;
119 writel(val
, SP5100_WDT_CONTROL(tcobase
));
120 spin_unlock_irqrestore(&tco_lock
, flags
);
123 static int tco_timer_set_heartbeat(int t
)
127 if (t
< 0 || t
> 0xffff)
130 /* Write new heartbeat to watchdog */
131 spin_lock_irqsave(&tco_lock
, flags
);
132 writel(t
, SP5100_WDT_COUNT(tcobase
));
133 spin_unlock_irqrestore(&tco_lock
, flags
);
139 static void tco_timer_enable(void)
143 if (sp5100_tco_pci
->revision
>= 0x40) {
144 /* For SB800 or later */
145 /* Set the Watchdog timer resolution to 1 sec */
146 outb(SB800_PM_WATCHDOG_CONFIG
, SB800_IO_PM_INDEX_REG
);
147 val
= inb(SB800_IO_PM_DATA_REG
);
148 val
|= SB800_PM_WATCHDOG_SECOND_RES
;
149 outb(val
, SB800_IO_PM_DATA_REG
);
151 /* Enable watchdog decode bit and watchdog timer */
152 outb(SB800_PM_WATCHDOG_CONTROL
, SB800_IO_PM_INDEX_REG
);
153 val
= inb(SB800_IO_PM_DATA_REG
);
154 val
|= SB800_PCI_WATCHDOG_DECODE_EN
;
155 val
&= ~SB800_PM_WATCHDOG_DISABLE
;
156 outb(val
, SB800_IO_PM_DATA_REG
);
158 /* For SP5100 or SB7x0 */
159 /* Enable watchdog decode bit */
160 pci_read_config_dword(sp5100_tco_pci
,
161 SP5100_PCI_WATCHDOG_MISC_REG
,
164 val
|= SP5100_PCI_WATCHDOG_DECODE_EN
;
166 pci_write_config_dword(sp5100_tco_pci
,
167 SP5100_PCI_WATCHDOG_MISC_REG
,
170 /* Enable Watchdog timer and set the resolution to 1 sec */
171 outb(SP5100_PM_WATCHDOG_CONTROL
, SP5100_IO_PM_INDEX_REG
);
172 val
= inb(SP5100_IO_PM_DATA_REG
);
173 val
|= SP5100_PM_WATCHDOG_SECOND_RES
;
174 val
&= ~SP5100_PM_WATCHDOG_DISABLE
;
175 outb(val
, SP5100_IO_PM_DATA_REG
);
179 static void tco_timer_disable(void)
183 if (sp5100_tco_pci
->revision
>= 0x40) {
184 /* For SB800 or later */
185 /* Enable watchdog decode bit and Disable watchdog timer */
186 outb(SB800_PM_WATCHDOG_CONTROL
, SB800_IO_PM_INDEX_REG
);
187 val
= inb(SB800_IO_PM_DATA_REG
);
188 val
|= SB800_PCI_WATCHDOG_DECODE_EN
;
189 val
|= SB800_PM_WATCHDOG_DISABLE
;
190 outb(val
, SB800_IO_PM_DATA_REG
);
192 /* For SP5100 or SB7x0 */
193 /* Enable watchdog decode bit */
194 pci_read_config_dword(sp5100_tco_pci
,
195 SP5100_PCI_WATCHDOG_MISC_REG
,
198 val
|= SP5100_PCI_WATCHDOG_DECODE_EN
;
200 pci_write_config_dword(sp5100_tco_pci
,
201 SP5100_PCI_WATCHDOG_MISC_REG
,
204 /* Disable Watchdog timer */
205 outb(SP5100_PM_WATCHDOG_CONTROL
, SP5100_IO_PM_INDEX_REG
);
206 val
= inb(SP5100_IO_PM_DATA_REG
);
207 val
|= SP5100_PM_WATCHDOG_DISABLE
;
208 outb(val
, SP5100_IO_PM_DATA_REG
);
213 * /dev/watchdog handling
216 static int sp5100_tco_open(struct inode
*inode
, struct file
*file
)
218 /* /dev/watchdog can only be opened once */
219 if (test_and_set_bit(0, &timer_alive
))
222 /* Reload and activate timer */
224 tco_timer_keepalive();
225 return nonseekable_open(inode
, file
);
228 static int sp5100_tco_release(struct inode
*inode
, struct file
*file
)
230 /* Shut off the timer. */
231 if (tco_expect_close
== 42) {
234 pr_crit("Unexpected close, not stopping watchdog!\n");
235 tco_timer_keepalive();
237 clear_bit(0, &timer_alive
);
238 tco_expect_close
= 0;
242 static ssize_t
sp5100_tco_write(struct file
*file
, const char __user
*data
,
243 size_t len
, loff_t
*ppos
)
245 /* See if we got the magic character 'V' and reload the timer */
250 /* note: just in case someone wrote the magic character
251 * five months ago... */
252 tco_expect_close
= 0;
254 /* scan to see whether or not we got the magic character
256 for (i
= 0; i
!= len
; i
++) {
258 if (get_user(c
, data
+ i
))
261 tco_expect_close
= 42;
265 /* someone wrote to us, we should reload the timer */
266 tco_timer_keepalive();
271 static long sp5100_tco_ioctl(struct file
*file
, unsigned int cmd
,
274 int new_options
, retval
= -EINVAL
;
276 void __user
*argp
= (void __user
*)arg
;
277 int __user
*p
= argp
;
278 static const struct watchdog_info ident
= {
279 .options
= WDIOF_SETTIMEOUT
|
280 WDIOF_KEEPALIVEPING
|
282 .firmware_version
= 0,
283 .identity
= TCO_MODULE_NAME
,
287 case WDIOC_GETSUPPORT
:
288 return copy_to_user(argp
, &ident
,
289 sizeof(ident
)) ? -EFAULT
: 0;
290 case WDIOC_GETSTATUS
:
291 case WDIOC_GETBOOTSTATUS
:
292 return put_user(0, p
);
293 case WDIOC_SETOPTIONS
:
294 if (get_user(new_options
, p
))
296 if (new_options
& WDIOS_DISABLECARD
) {
300 if (new_options
& WDIOS_ENABLECARD
) {
302 tco_timer_keepalive();
306 case WDIOC_KEEPALIVE
:
307 tco_timer_keepalive();
309 case WDIOC_SETTIMEOUT
:
310 if (get_user(new_heartbeat
, p
))
312 if (tco_timer_set_heartbeat(new_heartbeat
))
314 tco_timer_keepalive();
316 case WDIOC_GETTIMEOUT
:
317 return put_user(heartbeat
, p
);
327 static const struct file_operations sp5100_tco_fops
= {
328 .owner
= THIS_MODULE
,
330 .write
= sp5100_tco_write
,
331 .unlocked_ioctl
= sp5100_tco_ioctl
,
332 .open
= sp5100_tco_open
,
333 .release
= sp5100_tco_release
,
336 static struct miscdevice sp5100_tco_miscdev
= {
337 .minor
= WATCHDOG_MINOR
,
339 .fops
= &sp5100_tco_fops
,
343 * Data for PCI driver interface
345 * This data only exists for exporting the supported
346 * PCI ids via MODULE_DEVICE_TABLE. We do not actually
347 * register a pci_driver, because someone else might
348 * want to register another driver on the same PCI id.
350 static DEFINE_PCI_DEVICE_TABLE(sp5100_tco_pci_tbl
) = {
351 { PCI_VENDOR_ID_ATI
, PCI_DEVICE_ID_ATI_SBX00_SMBUS
, PCI_ANY_ID
,
353 { 0, }, /* End of list */
355 MODULE_DEVICE_TABLE(pci
, sp5100_tco_pci_tbl
);
358 * Init & exit routines
360 static unsigned char sp5100_tco_setupdevice(void)
362 struct pci_dev
*dev
= NULL
;
363 const char *dev_name
= NULL
;
365 u32 index_reg
, data_reg
, base_addr
;
367 /* Match the PCI device */
368 for_each_pci_dev(dev
) {
369 if (pci_match_id(sp5100_tco_pci_tbl
, dev
) != NULL
) {
370 sp5100_tco_pci
= dev
;
378 pr_info("PCI Revision ID: 0x%x\n", sp5100_tco_pci
->revision
);
381 * Determine type of southbridge chipset.
383 if (sp5100_tco_pci
->revision
>= 0x40) {
384 dev_name
= SB800_DEVNAME
;
385 index_reg
= SB800_IO_PM_INDEX_REG
;
386 data_reg
= SB800_IO_PM_DATA_REG
;
387 base_addr
= SB800_PM_WATCHDOG_BASE
;
389 dev_name
= SP5100_DEVNAME
;
390 index_reg
= SP5100_IO_PM_INDEX_REG
;
391 data_reg
= SP5100_IO_PM_DATA_REG
;
392 base_addr
= SP5100_PM_WATCHDOG_BASE
;
395 /* Request the IO ports used by this driver */
396 pm_iobase
= SP5100_IO_PM_INDEX_REG
;
397 if (!request_region(pm_iobase
, SP5100_PM_IOPORTS_SIZE
, dev_name
)) {
398 pr_err("I/O address 0x%04x already in use\n", pm_iobase
);
403 * First, Find the watchdog timer MMIO address from indirect I/O.
405 outb(base_addr
+3, index_reg
);
407 outb(base_addr
+2, index_reg
);
408 val
= val
<< 8 | inb(data_reg
);
409 outb(base_addr
+1, index_reg
);
410 val
= val
<< 8 | inb(data_reg
);
411 outb(base_addr
+0, index_reg
);
412 /* Low three bits of BASE are reserved */
413 val
= val
<< 8 | (inb(data_reg
) & 0xf8);
415 pr_debug("Got 0x%04x from indirect I/O\n", val
);
417 /* Check MMIO address conflict */
418 if (request_mem_region_exclusive(val
, SP5100_WDT_MEM_MAP_SIZE
,
422 pr_debug("MMIO address 0x%04x already in use\n", val
);
425 * Secondly, Find the watchdog timer MMIO address
426 * from SBResource_MMIO register.
428 if (sp5100_tco_pci
->revision
>= 0x40) {
429 /* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
430 outb(SB800_PM_ACPI_MMIO_EN
+3, SB800_IO_PM_INDEX_REG
);
431 val
= inb(SB800_IO_PM_DATA_REG
);
432 outb(SB800_PM_ACPI_MMIO_EN
+2, SB800_IO_PM_INDEX_REG
);
433 val
= val
<< 8 | inb(SB800_IO_PM_DATA_REG
);
434 outb(SB800_PM_ACPI_MMIO_EN
+1, SB800_IO_PM_INDEX_REG
);
435 val
= val
<< 8 | inb(SB800_IO_PM_DATA_REG
);
436 outb(SB800_PM_ACPI_MMIO_EN
+0, SB800_IO_PM_INDEX_REG
);
437 val
= val
<< 8 | inb(SB800_IO_PM_DATA_REG
);
439 /* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
440 pci_read_config_dword(sp5100_tco_pci
,
441 SP5100_SB_RESOURCE_MMIO_BASE
, &val
);
444 /* The SBResource_MMIO is enabled and mapped memory space? */
445 if ((val
& (SB800_ACPI_MMIO_DECODE_EN
| SB800_ACPI_MMIO_SEL
)) ==
446 SB800_ACPI_MMIO_DECODE_EN
) {
447 /* Clear unnecessary the low twelve bits */
449 /* Add the Watchdog Timer offset to base address. */
450 val
+= SB800_PM_WDT_MMIO_OFFSET
;
451 /* Check MMIO address conflict */
452 if (request_mem_region_exclusive(val
, SP5100_WDT_MEM_MAP_SIZE
,
454 pr_debug("Got 0x%04x from SBResource_MMIO register\n",
458 pr_debug("MMIO address 0x%04x already in use\n", val
);
460 pr_debug("SBResource_MMIO is disabled(0x%04x)\n", val
);
463 * Lastly re-programming the watchdog timer MMIO address,
464 * This method is a last resort...
466 * Before re-programming, to ensure that the watchdog timer
467 * is disabled, disable the watchdog timer.
473 * Force the use of watchdog timer MMIO address, and aligned to
479 pr_info("Force the use of 0x%04x as MMIO address\n", val
);
482 * Get empty slot into the resource tree for watchdog timer.
484 if (allocate_resource(&iomem_resource
,
486 SP5100_WDT_MEM_MAP_SIZE
,
492 pr_err("MMIO allocation failed\n");
496 val
= resbase_phys
= wdt_res
.start
;
497 pr_debug("Got 0x%04x from resource tree\n", val
);
500 /* Restore to the low three bits, if chipset is SB8x0(or later) */
501 if (sp5100_tco_pci
->revision
>= 0x40) {
503 reserved_bit
= inb(base_addr
) & 0x7;
504 val
|= (u32
)reserved_bit
;
507 /* Re-programming the watchdog timer base address */
508 outb(base_addr
+0, index_reg
);
509 /* Low three bits of BASE are reserved */
510 outb((val
>> 0) & 0xf8, data_reg
);
511 outb(base_addr
+1, index_reg
);
512 outb((val
>> 8) & 0xff, data_reg
);
513 outb(base_addr
+2, index_reg
);
514 outb((val
>> 16) & 0xff, data_reg
);
515 outb(base_addr
+3, index_reg
);
516 outb((val
>> 24) & 0xff, data_reg
);
519 * Clear unnecessary the low three bits,
520 * if chipset is SB8x0(or later)
522 if (sp5100_tco_pci
->revision
>= 0x40)
525 if (!request_mem_region_exclusive(val
, SP5100_WDT_MEM_MAP_SIZE
,
527 pr_err("MMIO address 0x%04x already in use\n", val
);
534 tcobase
= ioremap(val
, SP5100_WDT_MEM_MAP_SIZE
);
536 pr_err("failed to get tcobase address\n");
537 goto unreg_mem_region
;
540 pr_info("Using 0x%04x for watchdog MMIO address\n", val
);
542 /* Setup the watchdog timer */
545 /* Check that the watchdog action is set to reset the system */
546 val
= readl(SP5100_WDT_CONTROL(tcobase
));
548 * Save WatchDogFired status, because WatchDogFired flag is
551 tco_wdt_fired
= val
& SP5100_PM_WATCHDOG_FIRED
;
552 val
&= ~SP5100_PM_WATCHDOG_ACTION_RESET
;
553 writel(val
, SP5100_WDT_CONTROL(tcobase
));
555 /* Set a reasonable heartbeat before we stop the timer */
556 tco_timer_set_heartbeat(heartbeat
);
559 * Stop the TCO before we change anything so we don't race with
568 release_mem_region(tcobase_phys
, SP5100_WDT_MEM_MAP_SIZE
);
571 release_resource(&wdt_res
);
573 release_region(pm_iobase
, SP5100_PM_IOPORTS_SIZE
);
578 static int sp5100_tco_init(struct platform_device
*dev
)
584 * Check whether or not the hardware watchdog is there. If found, then
587 if (!sp5100_tco_setupdevice())
590 /* Check to see if last reboot was due to watchdog timeout */
591 pr_info("Last reboot was %striggered by watchdog.\n",
592 tco_wdt_fired
? "" : "not ");
595 * Check that the heartbeat value is within it's range.
596 * If not, reset to the default.
598 if (tco_timer_set_heartbeat(heartbeat
)) {
599 heartbeat
= WATCHDOG_HEARTBEAT
;
600 tco_timer_set_heartbeat(heartbeat
);
603 ret
= misc_register(&sp5100_tco_miscdev
);
605 pr_err("cannot register miscdev on minor=%d (err=%d)\n",
606 WATCHDOG_MINOR
, ret
);
610 clear_bit(0, &timer_alive
);
612 /* Show module parameters */
613 if (force_addr
== tcobase_phys
)
614 /* The force_addr is vaild */
615 sprintf(addr_str
, "0x%04x", force_addr
);
617 strcpy(addr_str
, "none");
619 pr_info("initialized (0x%p). heartbeat=%d sec (nowayout=%d, "
621 tcobase
, heartbeat
, nowayout
, addr_str
);
627 release_mem_region(tcobase_phys
, SP5100_WDT_MEM_MAP_SIZE
);
629 release_resource(&wdt_res
);
630 release_region(pm_iobase
, SP5100_PM_IOPORTS_SIZE
);
634 static void sp5100_tco_cleanup(void)
636 /* Stop the timer before we leave */
641 misc_deregister(&sp5100_tco_miscdev
);
643 release_mem_region(tcobase_phys
, SP5100_WDT_MEM_MAP_SIZE
);
645 release_resource(&wdt_res
);
646 release_region(pm_iobase
, SP5100_PM_IOPORTS_SIZE
);
649 static int sp5100_tco_remove(struct platform_device
*dev
)
652 sp5100_tco_cleanup();
656 static void sp5100_tco_shutdown(struct platform_device
*dev
)
661 static struct platform_driver sp5100_tco_driver
= {
662 .probe
= sp5100_tco_init
,
663 .remove
= sp5100_tco_remove
,
664 .shutdown
= sp5100_tco_shutdown
,
666 .owner
= THIS_MODULE
,
667 .name
= TCO_MODULE_NAME
,
671 static int __init
sp5100_tco_init_module(void)
675 pr_info("SP5100/SB800 TCO WatchDog Timer Driver v%s\n", TCO_VERSION
);
677 err
= platform_driver_register(&sp5100_tco_driver
);
681 sp5100_tco_platform_device
= platform_device_register_simple(
682 TCO_MODULE_NAME
, -1, NULL
, 0);
683 if (IS_ERR(sp5100_tco_platform_device
)) {
684 err
= PTR_ERR(sp5100_tco_platform_device
);
685 goto unreg_platform_driver
;
690 unreg_platform_driver
:
691 platform_driver_unregister(&sp5100_tco_driver
);
695 static void __exit
sp5100_tco_cleanup_module(void)
697 platform_device_unregister(sp5100_tco_platform_device
);
698 platform_driver_unregister(&sp5100_tco_driver
);
699 pr_info("SP5100/SB800 TCO Watchdog Module Unloaded\n");
702 module_init(sp5100_tco_init_module
);
703 module_exit(sp5100_tco_cleanup_module
);
705 MODULE_AUTHOR("Priyanka Gupta");
706 MODULE_DESCRIPTION("TCO timer driver for SP5100/SB800 chipset");
707 MODULE_LICENSE("GPL");
708 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);