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authorhuang lin <hl@rock-chips.com>2014-10-31 16:40:42 +0800
committerPatrick Georgi <pgeorgi@google.com>2015-04-10 11:58:18 +0200
commitd1bdef008a33e4e9583606feb8747a4d0d249ef1 (patch)
tree8e63164cda0d74dff50b1e16fe18ad9080eff66c /src/mainboard
parentc06a962271053d1fbb280e28e1cd5788132d942c (diff)
downloadcoreboot-d1bdef008a33e4e9583606feb8747a4d0d249ef1.tar.xz
rk3288: slowly raise to max cpu voltage to prevent overshoot
slowly raise to max cpu voltage to prevent overshoot, and in our experience,when cpu run in 1.8GHz,the vdd_cpu must up to 1.4V BUG=chrome-os-partner:32716, chrome-os-partner:31896 TEST=Boot on veyron_pinky rev2,check the rk808 buck1 voltage 1400mv and measure the overshoot is 1440mv Change-Id: I759840bd8cf57a5589bf1862d04803f80f804164 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 567f616ff091883ed3275b407859c9399db981b2 Original-Change-Id: I9bb739b49ae4b4f7a60133fa38b0fe51b95c0d78 Original-Signed-off-by: huang lin <hl@rock-chips.com> Original-Reviewed-on: https://chromium-review.googlesource.com/226753 Original-Reviewed-by: Doug Anderson <dianders@chromium.org> Original-Reviewed-by: Julius Werner <jwerner@chromium.org> Reviewed-on: http://review.coreboot.org/9408 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/mainboard')
-rw-r--r--src/mainboard/google/veyron_pinky/bootblock.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/src/mainboard/google/veyron_pinky/bootblock.c b/src/mainboard/google/veyron_pinky/bootblock.c
index b34199dfe5..99719c4024 100644
--- a/src/mainboard/google/veyron_pinky/bootblock.c
+++ b/src/mainboard/google/veyron_pinky/bootblock.c
@@ -27,16 +27,25 @@
#include <soc/rk808.h>
#include <soc/spi.h>
#include <vendorcode/google/chromeos/chromeos.h>
+#include <delay.h>
#include "board.h"
void bootblock_mainboard_init(void)
{
- /* cpu frequency will up to 1.8GHz, so the buck1 must up to 1.3v */
+ /* cpu frequency will up to 1.8GHz,
+ * in our experience the buck1
+ * must up to 1.4v
+ */
setbits_le32(&rk3288_pmu->iomux_i2c0scl, IOMUX_I2C0SCL);
setbits_le32(&rk3288_pmu->iomux_i2c0sda, IOMUX_I2C0SDA);
i2c_init(PMIC_BUS, 400*KHz);
- rk808_configure_buck(PMIC_BUS, 1, 1300);
+
+ /* Slowly raise to max CPU voltage to prevent overshoot */
+ rk808_configure_buck(PMIC_BUS, 1, 1200);
+ udelay(175);/* Must wait for voltage to stabilize,2mV/us */
+ rk808_configure_buck(PMIC_BUS, 1, 1400);
+ udelay(100);/* Must wait for voltage to stabilize,2mV/us */
rkclk_configure_cpu();
/* i2c1 for tpm */