From 71db049e7355f31604e2c04b6cabb71d02bd487d Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Sat, 17 Feb 2018 14:58:40 +0100 Subject: rtc: Add RTC range Add a way for drivers to inform the core of the supported date/time range. The core can then check whether the date/time or alarm is in the range before calling ->set_time, ->set_mmss or ->set_alarm. It returns -ERANGE when the time is out of range. Signed-off-by: Alexandre Belloni --- drivers/rtc/interface.c | 14 ++++++++++++++ drivers/rtc/rtc-sysfs.c | 12 ++++++++++++ 2 files changed, 26 insertions(+) (limited to 'drivers/rtc') diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index 7e253be19ba7..c068daebeec2 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -70,6 +70,13 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) if (err != 0) return err; + if (rtc->range_min != rtc->range_max) { + time64_t time = rtc_tm_to_time64(tm); + + if (time < rtc->range_min || time > rtc->range_max) + return -ERANGE; + } + err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; @@ -374,6 +381,13 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) if (err != 0) return err; + if (rtc->range_min != rtc->range_max) { + time64_t time = rtc_tm_to_time64(&alarm->time); + + if (time < rtc->range_min || time > rtc->range_max) + return -ERANGE; + } + err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; diff --git a/drivers/rtc/rtc-sysfs.c b/drivers/rtc/rtc-sysfs.c index 92ff2edb86a6..454da38c6012 100644 --- a/drivers/rtc/rtc-sysfs.c +++ b/drivers/rtc/rtc-sysfs.c @@ -248,6 +248,14 @@ offset_store(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RW(offset); +static ssize_t +range_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "[%lld,%llu]\n", to_rtc_device(dev)->range_min, + to_rtc_device(dev)->range_max); +} +static DEVICE_ATTR_RO(range); + static struct attribute *rtc_attrs[] = { &dev_attr_name.attr, &dev_attr_date.attr, @@ -257,6 +265,7 @@ static struct attribute *rtc_attrs[] = { &dev_attr_hctosys.attr, &dev_attr_wakealarm.attr, &dev_attr_offset.attr, + &dev_attr_range.attr, NULL, }; @@ -286,6 +295,9 @@ static umode_t rtc_attr_is_visible(struct kobject *kobj, } else if (attr == &dev_attr_offset.attr) { if (!rtc->ops->set_offset) mode = 0; + } else if (attr == &dev_attr_range.attr) { + if (!(rtc->range_max - rtc->range_min)) + mode = 0; } return mode; -- cgit v1.2.3