From a622f28cb249c9d88751ce2694c83a62c25c221e Mon Sep 17 00:00:00 2001
From: Yidi Lin <yidi.lin@mediatek.com>
Date: Fri, 29 Jan 2016 17:25:03 +0800
Subject: mediatek/mt8173: pll: raising the CPU core frequency

Runs the LITTLE core at highest freqency to speed up the boot time.
Set Vproc to 1.125V and set the freqency to 1.6Ghz for backward
compatibility. (The highest frequency for the IC before E3 is 1.6Ghz.)

BRANCH=none
BUG=chrome-os-partner:47422
TEST=flash the bootloader and measure the boottime by cbmem result

Change-Id: Id0b906bf34ac534667eb6e8f576e30942ceb923e
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 5fc38548d158158f07cded8cfc8ea5a0a7952161
Original-Change-Id: I62af26c13d98211974243100c581abcb5408fd63
Original-Signed-off-by: Yidi Lin <yidi.lin@mediatek.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/324685
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/13980
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
---
 src/mainboard/google/oak/romstage.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

(limited to 'src/mainboard/google')

diff --git a/src/mainboard/google/oak/romstage.c b/src/mainboard/google/oak/romstage.c
index d72693fa4d..3d018a02b1 100644
--- a/src/mainboard/google/oak/romstage.c
+++ b/src/mainboard/google/oak/romstage.c
@@ -17,7 +17,7 @@
 #include <arch/exception.h>
 #include <arch/io.h>
 #include <arch/mmu.h>
-
+#include <boardid.h>
 #include <cbfs.h>
 #include <cbmem.h>
 #include <console/console.h>
@@ -25,14 +25,20 @@
 #include <program_loading.h>
 #include <romstage_handoff.h>
 #include <symbols.h>
+#include <timer.h>
 #include <timestamp.h>
 
 #include <soc/emi.h>
 #include <soc/mmu_operations.h>
+#include <soc/mt6391.h>
+#include <soc/pll.h>
 #include <soc/rtc.h>
 
 void main(void)
 {
+	int stabilize_usec;
+	struct stopwatch sw;
+
 	timestamp_add_now(TS_START_ROMSTAGE);
 
 	/* init uart baudrate when pll on */
@@ -41,9 +47,23 @@ void main(void)
 
 	rtc_boot();
 
+	/* Raise CPU voltage to allow higher frequency */
+	stabilize_usec = mt6391_configure_ca53_voltage(1125000);
+
+	stopwatch_init_usecs_expire(&sw, stabilize_usec);
+
 	/* init memory */
 	mt_mem_init(get_sdram_config());
 
+	while (!stopwatch_expired(&sw))
+		;
+
+	/* Set to maximum frequency */
+	if (board_id() < 5)
+		mt_pll_raise_ca53_freq(1600 * MHz);
+	else
+		mt_pll_raise_ca53_freq(1700 * MHz);
+
 	mt8173_mmu_after_dram();
 
 	/* should be called after memory init */
-- 
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