diff options
| author | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2018-02-17 14:58:40 +0100 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2018-03-17 14:20:54 +0100 |
| commit | 71db049e7355f31604e2c04b6cabb71d02bd487d (patch) | |
| tree | 19743f8478631b847a11cf09690a6b4f28927e76 | |
| parent | 236b7187034e87bd46eb535ab4f276267ef66ee4 (diff) | |
| download | linux-71db049e7355f31604e2c04b6cabb71d02bd487d.tar.bz2 | |
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 <alexandre.belloni@bootlin.com>
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-rtc | 8 | ||||
| -rw-r--r-- | drivers/rtc/interface.c | 14 | ||||
| -rw-r--r-- | drivers/rtc/rtc-sysfs.c | 12 | ||||
| -rw-r--r-- | include/linux/rtc.h | 3 |
4 files changed, 37 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-rtc b/Documentation/ABI/testing/sysfs-class-rtc index 792a38300336..95984289a4ee 100644 --- a/Documentation/ABI/testing/sysfs-class-rtc +++ b/Documentation/ABI/testing/sysfs-class-rtc @@ -43,6 +43,14 @@ Contact: linux-rtc@vger.kernel.org Description: (RO) The name of the RTC corresponding to this sysfs directory +What: /sys/class/rtc/rtcX/range +Date: January 2018 +KernelVersion: 4.16 +Contact: linux-rtc@vger.kernel.org +Description: + Valid time range for the RTC, as seconds from epoch, formatted + as [min, max] + What: /sys/class/rtc/rtcX/since_epoch Date: March 2006 KernelVersion: 2.6.17 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; diff --git a/include/linux/rtc.h b/include/linux/rtc.h index 3b65b201169c..c78528c394e5 100644 --- a/include/linux/rtc.h +++ b/include/linux/rtc.h @@ -150,6 +150,9 @@ struct rtc_device { bool nvram_old_abi; struct bin_attribute *nvram; + time64_t range_min; + timeu64_t range_max; + #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL struct work_struct uie_task; struct timer_list uie_timer; |