Messages in this thread | | | Date | Tue, 25 Jul 2006 17:36:53 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] RTC: Add mmap method to rtc character driver |
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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.
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