tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
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Documentation/ABI/testing/rtc-cdev
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Documentation/ABI/testing/rtc-cdev
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Requires a separate RTC_PIE_ON call to enable the periodic
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interrupts.
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* RTC_VL_READ: Read the voltage inputs status of the RTC when
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supported. The value is a bit field of RTC_VL_*, giving the
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status of the main and backup voltages.
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* RTC_VL_CLEAR: Clear the voltage status of the RTC. Some RTCs
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need user interaction when the backup power provider is
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replaced or charged to be able to clear the status.
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The ioctl() calls supported by the older /dev/rtc interface are
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also supported by the newer RTC class framework. However,
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because the chips and systems are not standardized, some PC/AT