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authorZhao Yakui <yakui.zhao@intel.com>2008-04-28 02:11:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-28 08:58:17 -0700
commitc116bc2ae516e9949d645bc75b1ee294ff15db23 (patch)
tree9296da3e37dfc8f80566624faf781f19d41ea9f1
parente2bfe3424b368e977002fc58f81536d5d8ea9449 (diff)
rtc: add the support for alarm time relative to current time in sysfs
In current kernel if we want to set the alarm time, the absolute time the seconds relative to 1970-01-01 00:00:00) should be written into /sys/class/rtc/rtc0/wakealarm. It is not convenient. It is more reasonable to add the support for the alarm time relative to current RTC time.(the unit is second) For example: If the RTC is required to generate alarm after 2 minutes, the following will be OK. echo +120 > /sys/class/rtc/rtc0/wakealarm or echo +0x78 > /sys/class/rtc/rtc0/wakealarm Signed-off-by: Zhao Yakui <yakui.zhao@intel.com> Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/rtc/rtc-sysfs.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c
index 4d27ccc4fc0..2531ce4c9db 100644
--- a/drivers/rtc/rtc-sysfs.c
+++ b/drivers/rtc/rtc-sysfs.c
@@ -145,6 +145,8 @@ rtc_sysfs_set_wakealarm(struct device *dev, struct device_attribute *attr,
unsigned long now, alarm;
struct rtc_wkalrm alm;
struct rtc_device *rtc = to_rtc_device(dev);
+ char *buf_ptr;
+ int adjust = 0;
/* Only request alarms that trigger in the future. Disable them
* by writing another time, e.g. 0 meaning Jan 1 1970 UTC.
@@ -154,7 +156,15 @@ rtc_sysfs_set_wakealarm(struct device *dev, struct device_attribute *attr,
return retval;
rtc_tm_to_time(&alm.time, &now);
- alarm = simple_strtoul(buf, NULL, 0);
+ buf_ptr = (char *)buf;
+ if (*buf_ptr == '+') {
+ buf_ptr++;
+ adjust = 1;
+ }
+ alarm = simple_strtoul(buf_ptr, NULL, 0);
+ if (adjust) {
+ alarm += now;
+ }
if (alarm > now) {
/* Avoid accidentally clobbering active alarms; we can't
* entirely prevent that here, without even the minimal