include/linux/acpi_pmtmr.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ACPI_PMTMR_H_
   3 #define _ACPI_PMTMR_H_
   4
   5 #include <linux/clocksource.h>
   6
   7 /* Number of PMTMR ticks expected during calibration run */
   8 #define PMTMR_TICKS_PER_SEC 3579545
   9
  10 /* limit it to 24 bits */
  11 #define ACPI_PM_MASK CLOCKSOURCE_MASK(24)
  12
  13 /* Overrun value */
  14 #define ACPI_PM_OVRRUN  (1<<24)
  15
  16 #ifdef CONFIG_X86_PM_TIMER
  17
  18 extern u32 acpi_pm_read_verified(void);
  19 extern u32 pmtmr_ioport;
  20
  21 static inline u32 acpi_pm_read_early(void)
  22 {
  23         if (!pmtmr_ioport)
  24                 return 0;
  25         /* mask the output to 24 bits */
  26         return acpi_pm_read_verified() & ACPI_PM_MASK;
  27 }
  28
  29 #else
  30
  31 static inline u32 acpi_pm_read_early(void)
  32 {
  33         return 0;
  34 }
  35
  36 #endif
  37
  38 #endif
  39