diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-20 08:15:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-09-20 08:15:23 -0700 |
| commit | bdab18633a302c82b5e5d5dbc4e38b0baf9c0837 (patch) | |
| tree | 0446500af9a76d4e8b2a72a0a41391ceede73a10 /Documentation/ABI/testing/rtc-cdev | |
| download | linux-stable-bdab18633a302c82b5e5d5dbc4e38b0baf9c0837.tar.gz linux-stable-bdab18633a302c82b5e5d5dbc4e38b0baf9c0837.zip | |
Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipgrafted
Pull futex fix from Ingo Molnar:
- Also allocate a default private futex hash on vfork() as well, to
avoid races with (private) futex waiters (Peter Zijlstra)
* tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Also allocate private hash on vfork()
Diffstat (limited to 'Documentation/ABI/testing/rtc-cdev')
| -rw-r--r-- | Documentation/ABI/testing/rtc-cdev | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/rtc-cdev b/Documentation/ABI/testing/rtc-cdev new file mode 100644 index 000000000..cec099a27 --- /dev/null +++ b/Documentation/ABI/testing/rtc-cdev @@ -0,0 +1,50 @@ +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 up to 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. + + * 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 + 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. |
