From 790a19f18a70bf1e30b6b4d00559e1bb8a3f7e23 Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Sat, 14 Dec 2019 23:02:44 +0100 Subject: [PATCH] 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 --- Documentation/ABI/testing/rtc-cdev | 8 ++++++++ 1 file changed, 8 insertions(+) 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