Re: [PATCH] RTC: Add mmap method to rtc character driver

Neil Horman wrote:

It there any arch for which the rtc driver doesn't function?

Yes, there are plenty of systems which don't have an RTC, or have an RTC which can't generate interrupts.

Ok, for those implementations which don't have an RTC that the rtc driver can
drive, the mmap functionality will not work, but at that point what interface
are you left with at all for obtaining periodic time?

Depends completely on the hardware. Some hardware will rely on cycle counters, some may rely on I/O devices which may or may not be mappable into user space, and some will have to enter the kernel.

These aren't compatible with your programming model.

	-hpa
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• References:
  • Re: [PATCH] RTC: Add mmap method to rtc character driver
    • From: Segher Boessenkool <[email protected]>
  • Re: [PATCH] RTC: Add mmap method to rtc character driver
    • From: Neil Horman <[email protected]>
  • Re: Re: [PATCH] RTC: Add mmap method to rtc character driver
    • From: "Dave Airlie" <[email protected]>
  • Re: [PATCH] RTC: Add mmap method to rtc character driver
    • From: "H. Peter Anvin" <[email protected]>
  • Re: [PATCH] RTC: Add mmap method to rtc character driver
    • From: Neil Horman <[email protected]>
  • Re: [PATCH] RTC: Add mmap method to rtc character driver
    • From: "H. Peter Anvin" <[email protected]>
  • Re: [PATCH] RTC: Add mmap method to rtc character driver
    • From: Neil Horman <[email protected]>
  • Re: [PATCH] RTC: Add mmap method to rtc character driver
    • From: Segher Boessenkool <[email protected]>
  • Re: [PATCH] RTC: Add mmap method to rtc character driver
    • From: Neil Horman <[email protected]>
  • Re: [PATCH] RTC: Add mmap method to rtc character driver
    • From: "H. Peter Anvin" <[email protected]>
  • Re: [PATCH] RTC: Add mmap method to rtc character driver
    • From: Neil Horman <[email protected]>

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