diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2007-02-16 01:27:57 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-16 08:13:58 -0800 |
| commit | d66bea57e779cd592657cca6e61345ae899b78d9 (patch) | |
| tree | 70fe41bf930ac96a59d594ba5a37272a3df775e0 /include/linux | |
| parent | 169a0abbe32813af4904cc1605c0f7ea0534f77b (diff) | |
[PATCH] Allow early access to the power management timer
Allow early access to the power management timer by exposing the verified read
function and providing a helper function which checks the pmtmr_ioport
variable and returns either the pm timer readout or 0 in case the pm timer is
not available.
Create a new header file and replace also the ifdef'ed extern definition in
arch/i386/kernel/acpi/boot.c
This is a preperatory patch for the rework of the local apic timer
calibration.
No functional changes.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/acpi_pmtmr.h | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/include/linux/acpi_pmtmr.h b/include/linux/acpi_pmtmr.h new file mode 100644 index 00000000000..1d0ef1ae803 --- /dev/null +++ b/include/linux/acpi_pmtmr.h @@ -0,0 +1,38 @@ +#ifndef _ACPI_PMTMR_H_ +#define _ACPI_PMTMR_H_ + +#include <linux/clocksource.h> + +/* Number of PMTMR ticks expected during calibration run */ +#define PMTMR_TICKS_PER_SEC 3579545 + +/* limit it to 24 bits */ +#define ACPI_PM_MASK CLOCKSOURCE_MASK(24) + +/* Overrun value */ +#define ACPI_PM_OVRRUN (1<<24) + +#ifdef CONFIG_X86_PM_TIMER + +extern u32 acpi_pm_read_verified(void); +extern u32 pmtmr_ioport; + +static inline u32 acpi_pm_read_early(void) +{ + if (!pmtmr_ioport) + return 0; + /* mask the output to 24 bits */ + return acpi_pm_read_verified() & ACPI_PM_MASK; +} + +#else + +static inline u32 acpi_pm_read_early(void) +{ + return 0; +} + +#endif + +#endif + |