1 files changed, 26 insertions, 0 deletions
diff --git a/src/soc/intel/common/block/cpu/pm_timer_emulation.c b/src/soc/intel/common/block/cpu/pm_timer_emulation.c
new file mode 100644
index 0000000000..8f56da54c5
--- /dev/null
+++ b/src/soc/intel/common/block/cpu/pm_timer_emulation.c
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <cpu/x86/msr.h>
+#include <intelblocks/cpulib.h>
+#include <intelblocks/msr.h>
+#include <soc/iomap.h>
+#include <soc/pm.h>
+
+void enable_pm_timer_emulation(void)
+{
+	msr_t msr;
+
+	if (!CONFIG_CPU_XTAL_HZ)
+		return;
+
+	/*
+	 * The derived frequency is calculated as follows:
+	 * (clock * msr[63:32]) >> 32 = target frequency.
+	 * Back solve the multiplier so the 3.579545MHz ACPI timer frequency is used.
+	 */
+	msr.hi = (3579545ULL << 32) / CONFIG_CPU_XTAL_HZ;
+	/* Set PM1 timer IO port and enable */
+	msr.lo = (EMULATE_DELAY_VALUE << EMULATE_DELAY_OFFSET_VALUE) |
+		  EMULATE_PM_TMR_EN | (ACPI_BASE_ADDRESS + PM1_TMR);
+	wrmsr(MSR_EMULATE_PM_TIMER, msr);
+}