Patrick Georgi (pgeorgi@google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9408
-gerrit
commit 918a1554935bcefec6116c3e0bc418117b867b07 Author: huang lin hl@rock-chips.com Date: Fri Oct 31 16:40:42 2014 +0800
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 --- src/mainboard/google/veyron_pinky/bootblock.c | 13 +++++++++++-- src/soc/rockchip/rk3288/rk808.c | 1 - 2 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/src/mainboard/google/veyron_pinky/bootblock.c b/src/mainboard/google/veyron_pinky/bootblock.c index b34199d..99719c4 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 */ diff --git a/src/soc/rockchip/rk3288/rk808.c b/src/soc/rockchip/rk3288/rk808.c index aa39b8d..fea64e5 100644 --- a/src/soc/rockchip/rk3288/rk808.c +++ b/src/soc/rockchip/rk3288/rk808.c @@ -98,5 +98,4 @@ void rk808_configure_buck(uint8_t bus, int buck, int millivolts) } rk808_clrsetbits(bus, buck_reg, 0x3f, vsel); rk808_clrsetbits(bus, DCDC_EN, 0, 1 << (buck - 1)); - udelay(225);/* Must wait for voltage to stabilize */ }