1 files changed, 32 insertions, 0 deletions
diff --git a/src/soc/amd/stoneyridge/monotonic_timer.c b/src/soc/amd/stoneyridge/monotonic_timer.c
new file mode 100644
index 0000000000..170a640233
--- /dev/null
+++ b/src/soc/amd/stoneyridge/monotonic_timer.c
@@ -0,0 +1,32 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2018 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <cpu/x86/msr.h>
+#include <timer.h>
+
+#define CU_PTSC_MSR	0xc0010280
+#define PTSC_FREQ_MHZ	100
+
+void timer_monotonic_get(struct mono_time *mt)
+{
+	unsigned long long val;
+	msr_t msr;
+
+	msr = rdmsr(CU_PTSC_MSR);
+
+	val = ((unsigned long long)msr.hi << 32) | msr.lo;
+
+	mono_time_set_usecs(mt, val / PTSC_FREQ_MHZ);
+}