1 files changed, 39 insertions, 0 deletions
diff --git a/include/linux/acpi_pmtmr.h b/include/linux/acpi_pmtmr.h
new file mode 100644
index 000000000..50d88bf14
--- /dev/null
+++ b/include/linux/acpi_pmtmr.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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
+