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authorAtsushi Nemoto <anemo@mba.ocn.ne.jp>2007-07-17 07:05:04 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-17 13:23:09 -0400
commit617780d290bd6eb2b260928c6acff5b7c6084154 (patch)
tree74738cadd5a79613b6c7fbc0187743a9fe4d2a6b /drivers
parentcaaff562e0ba44a7991ee8322fa4a6891d939757 (diff)
rtc: watchdog support for rtc-m41t80 driver
Add a watchdog driver interface to rtc-m41t80 driver. This is derived from works by Alexander Bigga <ab@mycable.de> Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Alexander Bigga <ab@mycable.de> Cc: David Brownell <david-b@pacbell.net> Acked-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/rtc/Kconfig7
-rw-r--r--drivers/rtc/rtc-m41t80.c288
2 files changed, 295 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index fb9ce745cd30..359323378c55 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -224,6 +224,13 @@ config RTC_DRV_M41T80
224 This driver can also be built as a module. If so, the module 224 This driver can also be built as a module. If so, the module
225 will be called rtc-m41t80. 225 will be called rtc-m41t80.
226 226
227config RTC_DRV_M41T80_WDT
228 bool "ST M41T80 series RTC watchdog timer"
229 depends on RTC_DRV_M41T80
230 help
231 If you say Y here you will get support for the
232 watchdog timer in ST M41T80 RTC chips series.
233
227comment "SPI RTC drivers" 234comment "SPI RTC drivers"
228 depends on RTC_CLASS && SPI_MASTER 235 depends on RTC_CLASS && SPI_MASTER
229 236
diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
index 4875a4444216..80c4a8463065 100644
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -20,6 +20,13 @@
20#include <linux/i2c.h> 20#include <linux/i2c.h>
21#include <linux/rtc.h> 21#include <linux/rtc.h>
22#include <linux/bcd.h> 22#include <linux/bcd.h>
23#ifdef CONFIG_RTC_DRV_M41T80_WDT
24#include <linux/miscdevice.h>
25#include <linux/watchdog.h>
26#include <linux/reboot.h>
27#include <linux/fs.h>
28#include <linux/ioctl.h>
29#endif
23 30
24#define M41T80_REG_SSEC 0 31#define M41T80_REG_SSEC 0
25#define M41T80_REG_SEC 1 32#define M41T80_REG_SEC 1
@@ -480,6 +487,268 @@ static int m41t80_sysfs_register(struct device *dev)
480} 487}
481#endif 488#endif
482 489
490#ifdef CONFIG_RTC_DRV_M41T80_WDT
491/*
492 *****************************************************************************
493 *
494 * Watchdog Driver
495 *
496 *****************************************************************************
497 */
498static struct i2c_client *save_client;
499
500/* Default margin */
501#define WD_TIMO 60 /* 1..31 seconds */
502
503static int wdt_margin = WD_TIMO;
504module_param(wdt_margin, int, 0);
505MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)");
506
507static unsigned long wdt_is_open;
508static int boot_flag;
509
510/**
511 * wdt_ping:
512 *
513 * Reload counter one with the watchdog timeout. We don't bother reloading
514 * the cascade counter.
515 */
516static void wdt_ping(void)
517{
518 unsigned char i2c_data[2];
519 struct i2c_msg msgs1[1] = {
520 {
521 .addr = save_client->addr,
522 .flags = 0,
523 .len = 2,
524 .buf = i2c_data,
525 },
526 };
527 i2c_data[0] = 0x09; /* watchdog register */
528
529 if (wdt_margin > 31)
530 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */
531 else
532 /*
533 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02)
534 */
535 i2c_data[1] = wdt_margin<<2 | 0x82;
536
537 i2c_transfer(save_client->adapter, msgs1, 1);
538}
539
540/**
541 * wdt_disable:
542 *
543 * disables watchdog.
544 */
545static void wdt_disable(void)
546{
547 unsigned char i2c_data[2], i2c_buf[0x10];
548 struct i2c_msg msgs0[2] = {
549 {
550 .addr = save_client->addr,
551 .flags = 0,
552 .len = 1,
553 .buf = i2c_data,
554 },
555 {
556 .addr = save_client->addr,
557 .flags = I2C_M_RD,
558 .len = 1,
559 .buf = i2c_buf,
560 },
561 };
562 struct i2c_msg msgs1[1] = {
563 {
564 .addr = save_client->addr,
565 .flags = 0,
566 .len = 2,
567 .buf = i2c_data,
568 },
569 };
570
571 i2c_data[0] = 0x09;
572 i2c_transfer(save_client->adapter, msgs0, 2);
573
574 i2c_data[0] = 0x09;
575 i2c_data[1] = 0x00;
576 i2c_transfer(save_client->adapter, msgs1, 1);
577}
578
579/**
580 * wdt_write:
581 * @file: file handle to the watchdog
582 * @buf: buffer to write (unused as data does not matter here
583 * @count: count of bytes
584 * @ppos: pointer to the position to write. No seeks allowed
585 *
586 * A write to a watchdog device is defined as a keepalive signal. Any
587 * write of data will do, as we we don't define content meaning.
588 */
589static ssize_t wdt_write(struct file *file, const char __user *buf,
590 size_t count, loff_t *ppos)
591{
592 /* Can't seek (pwrite) on this device
593 if (ppos != &file->f_pos)
594 return -ESPIPE;
595 */
596 if (count) {
597 wdt_ping();
598 return 1;
599 }
600 return 0;
601}
602
603static ssize_t wdt_read(struct file *file, char __user *buf,
604 size_t count, loff_t *ppos)
605{
606 return 0;
607}
608
609/**
610 * wdt_ioctl:
611 * @inode: inode of the device
612 * @file: file handle to the device
613 * @cmd: watchdog command
614 * @arg: argument pointer
615 *
616 * The watchdog API defines a common set of functions for all watchdogs
617 * according to their available features. We only actually usefully support
618 * querying capabilities and current status.
619 */
620static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
621 unsigned long arg)
622{
623 int new_margin, rv;
624 static struct watchdog_info ident = {
625 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING |
626 WDIOF_SETTIMEOUT,
627 .firmware_version = 1,
628 .identity = "M41T80 WTD"
629 };
630
631 switch (cmd) {
632 case WDIOC_GETSUPPORT:
633 return copy_to_user((struct watchdog_info __user *)arg, &ident,
634 sizeof(ident)) ? -EFAULT : 0;
635
636 case WDIOC_GETSTATUS:
637 case WDIOC_GETBOOTSTATUS:
638 return put_user(boot_flag, (int __user *)arg);
639 case WDIOC_KEEPALIVE:
640 wdt_ping();
641 return 0;
642 case WDIOC_SETTIMEOUT:
643 if (get_user(new_margin, (int __user *)arg))
644 return -EFAULT;
645 /* Arbitrary, can't find the card's limits */
646 if (new_margin < 1 || new_margin > 124)
647 return -EINVAL;
648 wdt_margin = new_margin;
649 wdt_ping();
650 /* Fall */
651 case WDIOC_GETTIMEOUT:
652 return put_user(wdt_margin, (int __user *)arg);
653
654 case WDIOC_SETOPTIONS:
655 if (copy_from_user(&rv, (int __user *)arg, sizeof(int)))
656 return -EFAULT;
657
658 if (rv & WDIOS_DISABLECARD) {
659 printk(KERN_INFO
660 "rtc-m41t80: disable watchdog\n");
661 wdt_disable();
662 }
663
664 if (rv & WDIOS_ENABLECARD) {
665 printk(KERN_INFO
666 "rtc-m41t80: enable watchdog\n");
667 wdt_ping();
668 }
669
670 return -EINVAL;
671 }
672 return -ENOTTY;
673}
674
675/**
676 * wdt_open:
677 * @inode: inode of device
678 * @file: file handle to device
679 *
680 */
681static int wdt_open(struct inode *inode, struct file *file)
682{
683 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
684 if (test_and_set_bit(0, &wdt_is_open))
685 return -EBUSY;
686 /*
687 * Activate
688 */
689 wdt_is_open = 1;
690 return 0;
691 }
692 return -ENODEV;
693}
694
695/**
696 * wdt_close:
697 * @inode: inode to board
698 * @file: file handle to board
699 *
700 */
701static int wdt_release(struct inode *inode, struct file *file)
702{
703 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
704 clear_bit(0, &wdt_is_open);
705 return 0;
706}
707
708/**
709 * notify_sys:
710 * @this: our notifier block
711 * @code: the event being reported
712 * @unused: unused
713 *
714 * Our notifier is called on system shutdowns. We want to turn the card
715 * off at reboot otherwise the machine will reboot again during memory
716 * test or worse yet during the following fsck. This would suck, in fact
717 * trust me - if it happens it does suck.
718 */
719static int wdt_notify_sys(struct notifier_block *this, unsigned long code,
720 void *unused)
721{
722 if (code == SYS_DOWN || code == SYS_HALT)
723 /* Disable Watchdog */
724 wdt_disable();
725 return NOTIFY_DONE;
726}
727
728static const struct file_operations wdt_fops = {
729 .owner = THIS_MODULE,
730 .read = wdt_read,
731 .ioctl = wdt_ioctl,
732 .write = wdt_write,
733 .open = wdt_open,
734 .release = wdt_release,
735};
736
737static struct miscdevice wdt_dev = {
738 .minor = WATCHDOG_MINOR,
739 .name = "watchdog",
740 .fops = &wdt_fops,
741};
742
743/*
744 * The WDT card needs to learn about soft shutdowns in order to
745 * turn the timebomb registers off.
746 */
747static struct notifier_block wdt_notifier = {
748 .notifier_call = wdt_notify_sys,
749};
750#endif /* CONFIG_RTC_DRV_M41T80_WDT */
751
483/* 752/*
484 ***************************************************************************** 753 *****************************************************************************
485 * 754 *
@@ -572,6 +841,19 @@ static int m41t80_probe(struct i2c_client *client)
572 if (rc) 841 if (rc)
573 goto exit; 842 goto exit;
574 843
844#ifdef CONFIG_RTC_DRV_M41T80_WDT
845 if (chip->features & M41T80_FEATURE_HT) {
846 rc = misc_register(&wdt_dev);
847 if (rc)
848 goto exit;
849 rc = register_reboot_notifier(&wdt_notifier);
850 if (rc) {
851 misc_deregister(&wdt_dev);
852 goto exit;
853 }
854 save_client = client;
855 }
856#endif
575 return 0; 857 return 0;
576 858
577st_err: 859st_err:
@@ -595,6 +877,12 @@ static int m41t80_remove(struct i2c_client *client)
595 struct m41t80_data *clientdata = i2c_get_clientdata(client); 877 struct m41t80_data *clientdata = i2c_get_clientdata(client);
596 struct rtc_device *rtc = clientdata->rtc; 878 struct rtc_device *rtc = clientdata->rtc;
597 879
880#ifdef CONFIG_RTC_DRV_M41T80_WDT
881 if (clientdata->chip->features & M41T80_FEATURE_HT) {
882 misc_deregister(&wdt_dev);
883 unregister_reboot_notifier(&wdt_notifier);
884 }
885#endif
598 if (rtc) 886 if (rtc)
599 rtc_device_unregister(rtc); 887 rtc_device_unregister(rtc);
600 kfree(clientdata); 888 kfree(clientdata);