From c116bc2ae516e9949d645bc75b1ee294ff15db23 Mon Sep 17 00:00:00 2001 From: Zhao Yakui Date: Mon, 28 Apr 2008 02:11:58 -0700 Subject: [PATCH] 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 Signed-off-by: Zhang Rui Signed-off-by: David Brownell Cc: Alessandro Zummo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/rtc/rtc-sysfs.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c index 4d27ccc4fc06..2531ce4c9db0 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 -- 2.20.1