intel/fsp_broadwell_de: Add timestamp functionality

Add a little code to enable timestamps on FSP based implementation
of Broadwell-DE. I have tested it by reading back the timestamps
with cbmem utility once the board has booted into Lubuntu.

Change-Id: Idaa65a22a00382bf0c37acf2f5a1e07c6b1b42d9
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/21932
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/src/soc/intel/fsp_broadwell_de/tsc_freq.c b/src/soc/intel/fsp_broadwell_de/tsc_freq.c
new file mode 100644
index 0000000000..4225a3ab22
--- /dev/null
+++ b/src/soc/intel/fsp_broadwell_de/tsc_freq.c
@@ -0,0 +1,28 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2014 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; 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 <stdint.h>
+#include <cpu/x86/msr.h>
+#include <cpu/x86/tsc.h>
+#include <soc/msr.h>
+#include <soc/broadwell_de.h>
+
+unsigned long tsc_freq_mhz(void)
+{
+	msr_t platform_info;
+
+	platform_info = rdmsr(MSR_PLATFORM_INFO);
+	return CPU_BCLK * ((platform_info.lo >> 8) & 0xff);
+}