Messages in this thread | | | Date | Tue, 13 Jul 2010 17:45:36 +0800 | Subject | Question on HPET timer reading from device driver? | From | Samuel Xu <> |
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HI: I am a freshman for HPET timer. Previously, I use TSC counter, to use rdtsc to get the time stamp. elapsed cycle can be counter from 2 time stamps. As a advanced replacement of TSC, I suppose HPET timer can be conveniently to read time stamp from both kernel mode user and user mode apps. While I failed to find a way to get time stamp value of HPET in Linux kenerl (I am doing a driver and want to know elapsed cycle from driver code).
I tried hpet_readl() from my driver code, while hit compiling error. Is it a correct API for kernel driver to invoke? I also read the Linux Documentation of HPET, which contain a user mode demo app to generate a periodic timer via HPET, while missing the time stamp reading.
Any hint?
Thanks!
Samuel
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