diff options
| author | Aishwarya Pant <aishpant@gmail.com> | 2018-01-01 23:01:24 +0530 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2018-01-12 00:20:41 +0100 |
| commit | 796c0ad79ee65abb9c891e44ccd6e347a6be486f (patch) | |
| tree | 50cad654b08258997087d3376b8554bfaa441862 /Documentation/ABI/testing/rtc-cdev | |
| parent | d5bc5cde844ebecbc6fac2d65d23610cfd3affc3 (diff) | |
Documentation: rtc: move iotcl interface documentation to ABI
The ioctl interface should be in Documentation/ABI along with the rest
of the interfaces.
Signed-off-by: Aishwarya Pant <aishpant@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'Documentation/ABI/testing/rtc-cdev')
| -rw-r--r-- | Documentation/ABI/testing/rtc-cdev | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/rtc-cdev b/Documentation/ABI/testing/rtc-cdev new file mode 100644 index 000000000000..97447283f13b --- /dev/null +++ b/Documentation/ABI/testing/rtc-cdev @@ -0,0 +1,42 @@ +What: /dev/rtcX +Date: April 2005 +KernelVersion: 2.6.12 +Contact: linux-rtc@vger.kernel.org +Description: + The ioctl interface to drivers for real-time clocks (RTCs). + Following actions are supported: + + * RTC_RD_TIME, RTC_SET_TIME: Read or set the RTC time. Time + format is a Gregorian calendar date and 24 hour wall clock + time. + + * RTC_AIE_ON, RTC_AIE_OFF: Enable or disable the alarm interrupt + for RTCs that support alarms + + * RTC_ALM_READ, RTC_ALM_SET: Read or set the alarm time for + RTCs that support alarms. Can be set upto 24 hours in the + future. Requires a separate RTC_AIE_ON call to enable the + alarm interrupt. (Prefer to use RTC_WKALM_*) + + * RTC_WKALM_RD, RTC_WKALM_SET: For RTCs that support a more + powerful interface, which can issue alarms beyond 24 hours and + enable IRQs in the same request. + + * RTC_PIE_ON, RTC_PIE_OFF: Enable or disable the periodic + interrupt for RTCs that support periodic interrupts. + + * RTC_UIE_ON, RTC_UIE_OFF: Enable or disable the update + interrupt for RTCs that support it. + + * RTC_IRQP_READ, RTC_IRQP_SET: Read or set the frequency for + periodic interrupts for RTCs that support periodic interrupts. + Requires a separate RTC_PIE_ON call to enable the periodic + interrupts. + + 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 + functionality might not be provided. And in the same way, some + newer features -- including those enabled by ACPI -- are exposed + by the RTC class framework, but can't be supported by the older + driver. |