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Diffstat (limited to 'Documentation/timers/hpet.txt')
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diff --git a/Documentation/timers/hpet.txt b/Documentation/timers/hpet.txt deleted file mode 100644 index 767392ffd31..00000000000 --- a/Documentation/timers/hpet.txt +++ /dev/null @@ -1,30 +0,0 @@ - High Precision Event Timer Driver for Linux - -The High Precision Event Timer (HPET) hardware follows a specification -by Intel and Microsoft which can be found at - - http://www.intel.com/hardwaredesign/hpetspec_1.pdf - -Each HPET has one fixed-rate counter (at 10+ MHz, hence "High Precision") -and up to 32 comparators. Normally three or more comparators are provided, -each of which can generate oneshot interrupts and at least one of which has -additional hardware to support periodic interrupts. The comparators are -also called "timers", which can be misleading since usually timers are -independent of each other ... these share a counter, complicating resets. - -HPET devices can support two interrupt routing modes. In one mode, the -comparators are additional interrupt sources with no particular system -role. Many x86 BIOS writers don't route HPET interrupts at all, which -prevents use of that mode. They support the other "legacy replacement" -mode where the first two comparators block interrupts from 8254 timers -and from the RTC. - -The driver supports detection of HPET driver allocation and initialization -of the HPET before the driver module_init routine is called. This enables -platform code which uses timer 0 or 1 as the main timer to intercept HPET -initialization. An example of this initialization can be found in -arch/x86/kernel/hpet.c. - -The driver provides a userspace API which resembles the API found in the -RTC driver framework. An example user space program is provided in -file:Documentation/timers/hpet_example.c |