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| author | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2019-12-14 23:02:44 +0100 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2019-12-18 10:37:20 +0100 |
| commit | 790a19f18a70bf1e30b6b4d00559e1bb8a3f7e23 (patch) | |
| tree | deddcc9505524cc768693815162fd3305a6e1e93 /Documentation/ABI/testing | |
| parent | rtc: define RTC_VL_READ values (diff) | |
| download | linux-790a19f18a70bf1e30b6b4d00559e1bb8a3f7e23.tar.xz linux-790a19f18a70bf1e30b6b4d00559e1bb8a3f7e23.zip | |
rtc: Document RTC_VL_READ and RTC_VL_CLR ioctls
RTC_VL_READ and RTC_VL_CLR have been introduced in 2012 with commit
0f20b767e20a ("drivers/rtc/rtc-pcf8563.c: add RTC_VL_READ/RTC_VL_CLR ioctl
feature")
Document them now that they have been unified.
Link: https://lore.kernel.org/r/20191214220259.621996-3-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'Documentation/ABI/testing')
| -rw-r--r-- | Documentation/ABI/testing/rtc-cdev | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/rtc-cdev b/Documentation/ABI/testing/rtc-cdev index 97447283f13b..25910c3c3d7e 100644 --- a/Documentation/ABI/testing/rtc-cdev +++ b/Documentation/ABI/testing/rtc-cdev @@ -33,6 +33,14 @@ Description: Requires a separate RTC_PIE_ON call to enable the periodic interrupts. + * RTC_VL_READ: Read the voltage inputs status of the RTC when + supported. The value is a bit field of RTC_VL_*, giving the + status of the main and backup voltages. + + * RTC_VL_CLEAR: Clear the voltage status of the RTC. Some RTCs + need user interaction when the backup power provider is + replaced or charged to be able to clear the status. + The ioctl() calls supported by the older /dev/rtc interface are also supported by the newer RTC class framework. However, because the chips and systems are not standardized, some PC/AT |