Hi, Well, I had that patch: https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux.git/commit/?h=rtc-ranges&id=79729c30854986faf4d26b0303dba220f4ef89de part of a series I didn't send yet (it is still WIP and I just pushed it).
Can you rebase on top of that? The RO/RW annotation would be a nice addition. Please, move the ioctl documentation to its own file, Documentation/ABI/stable/rtc-cdev On 01/01/2018 at 17:27:26 +0530, Aishwarya Pant wrote: > +IOCTL interface > +--------------- > + > +What: /dev/rtc[0-*] The [0-*] range is not correct, it should be [0-9]+ > +Date: April 2005 > +KernelVersion: 2.6.12 > +Contact: Alexandre Belloni <alexandre.bell...@free-electrons.com> This must be the RTC mailing list. > +Description: The ioctl() calls supported by /dev/rtc are also supported by > + the 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. > + Out of context, this paragraph is weird. > + * RTC_RD_TIME, RTC_SET_TIME ... every RTC supports at > + least reading time, returning the result as a Gregorian > + calendar date and 24 hour wall clock time. To be most > + useful, this time may also be updated. > + > + * RTC_AIE_ON, RTC_AIE_OFF, RTC_ALM_SET, RTC_ALM_READ ... > + when the RTC is connected to an IRQ line, it can often > + issue an alarm IRQ up to 24 hours in the future. (Use > + RTC_WKALM_* by preference.) > + > + * RTC_WKALM_SET, RTC_WKALM_RD ... RTCs that can issue > + alarms beyond the next 24 hours use a slightly more > + powerful API, which supports setting the longer alarm > + time and enabling its IRQ using a single request (using > + the same model as EFI firmware). > + > + * RTC_UIE_ON, RTC_UIE_OFF ... if the RTC offers IRQs, the > + RTC framework will emulate this mechanism. > + > + * RTC_PIE_ON, RTC_PIE_OFF, RTC_IRQP_SET, RTC_IRQP_READ ... > + these icotls are emulated via a kernel hrtimer. > + > + In many cases, the RTC alarm can be a system wake event, used to > + force Linux out of a low power sleep state (or hibernation) back > + to a fully operational state. For example, a system could enter > + a deep power saving state until it's time to execute some > + scheduled tasks. > + > + Note that many of these ioctls are handled by the common rtc-dev > + interface. Some common examples: > + > + * RTC_RD_TIME, RTC_SET_TIME: the read_time/set_time > + functions will be called with appropriate values. > + > + * RTC_ALM_SET, RTC_ALM_READ, RTC_WKALM_SET, RTC_WKALM_RD: > + gets or sets the alarm rtc_timer. May call the set_alarm > + driver function. > + > + * RTC_IRQP_SET, RTC_IRQP_READ: These are emulated by the > + generic code. > + > + * RTC_PIE_ON, RTC_PIE_OFF: These are also emulated by the > + generic code. > + > + If all else fails, check out the > + tools/testing/selftests/timers/rtctest.c test! The reference to this test should probably stay in rtc.txt -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
