erebion/coreboot
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

rk3288: slowly raise to max cpu voltage to prevent overshoot

Browse source 
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: I9bb739b49ae4b4f7a60133fa38b0fe51b95c0d78
Signed-off-by: huang lin <hl@rock-chips.com>
Reviewed-on: https://chromium-review.googlesource.com/226753
Reviewed-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
This commit is contained in:
huang lin 2014-10-31 16:40:42 +08:00 • committed by chrome-internal-fetch
commit 567f616ff0
2 changed files with 11 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

13
src/mainboard/google/veyron_pinky/bootblock.c
View file

@ -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 */

1
src/soc/rockchip/rk3288/rk808.c
View file

@ -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 */
}