From 257eb1354e5fedb01b63ff327f64554a44547c22 Mon Sep 17 00:00:00 2001
From: Rex-BC Chen <rex-bc.chen@mediatek.corp-partner.google.com>
Date: Wed, 4 Aug 2021 11:00:53 +0800
Subject: mb/google/cherry: Improve boot time by raising little CPU frequency

Raise little CPU to 2GHz at romstage to improve boot time by about
100 ms.

BUG=b:195274787

Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Change-Id: Id6aac8f9db86a6c1e61ea94863f2cbde12c0482e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56844
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.corp-partner.google.com>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
---
 src/mainboard/google/cherry/romstage.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

(limited to 'src/mainboard')

diff --git a/src/mainboard/google/cherry/romstage.c b/src/mainboard/google/cherry/romstage.c
index c11fef45dc..71291c24a3 100644
--- a/src/mainboard/google/cherry/romstage.c
+++ b/src/mainboard/google/cherry/romstage.c
@@ -1,21 +1,33 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #include <arch/stages.h>
+#include <delay.h>
 #include <soc/clkbuf.h>
 #include <soc/emi.h>
 #include <soc/i2c.h>
 #include <soc/mt6315.h>
 #include <soc/mt6359p.h>
 #include <soc/mt6360.h>
+#include <soc/pll_common.h>
 #include <soc/pmif.h>
 #include <soc/rtc.h>
 #include <soc/scp.h>
 
+static void raise_little_cpu_freq(void)
+{
+	mt6359p_buck_set_voltage(MT6359P_SRAM_PROC1, 1000 * 1000);
+	mt6359p_buck_set_voltage(MT6359P_CORE, 1000 * 1000);
+	udelay(200);
+	mt_pll_raise_little_cpu_freq(2000 * MHz);
+	mt_pll_raise_cci_freq(1385 * MHz);
+}
+
 void platform_romstage_main(void)
 {
 	mtk_pmif_init();
 	mt6359p_init();
 	mt6315_init();
+	raise_little_cpu_freq();
 	mtk_i2c_bus_init(I2C7);
 	if (CONFIG(BOARD_GOOGLE_CHERRY))
 		mt6360_init(I2C7);
-- 
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