rockchip/rk3399: Clean up voltage rail settings

The CENTER LOGIC should always be 0.9V and can not be adjusted,
so use duty_ns = 2860 to correct CENTER LOGIC to 0.9V. And now
DDR seems to run stable at 800MHz on the gru board.

BRANCH=none
BUG=chrome-os-partner:54144, chrome-os-partner:53208
TEST=run "stressapptest -M 1024 -s 1000" and pass

Change-Id: Ia900e248c10ddd0ab630446a324cc0446c0fa49b
Signed-off-by: Martin Roth <martinroth@chromium.org>
Original-Commit-Id: f4fb1cefb59ac4099cef8b32a68ed9222e708478
Original-Change-Id: I2238da6c17908d09bc284b321d796901317ed9ef
Original-Signed-off-by: Lin Huang <hl@rock-chips.com>
Original-Signed-off-by: Douglas Anderson <dianders@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/352772
Reviewed-on: https://review.coreboot.org/15297
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>
This commit is contained in:
Lin Huang 2016-06-15 17:43:40 +08:00 committed by Martin Roth
parent 9e6b0ee2c4
commit 50df52244e
2 changed files with 31 additions and 18 deletions

View File

@ -49,6 +49,7 @@ romstage-y += romstage.c
romstage-y += tsadc.c
romstage-y += usb.c
romstage-y += gpio.c
romstage-y += saradc.c
romstage-y += ../common/gpio.c
################################################################################

View File

@ -19,6 +19,7 @@
#include <arch/exception.h>
#include <arch/io.h>
#include <arch/mmu.h>
#include <boardid.h>
#include <cbfs.h>
#include <console/console.h>
#include <delay.h>
@ -38,6 +39,7 @@ static const uint64_t dram_size =
static void init_dvs_outputs(void)
{
int duty_ns;
uint32_t i;
write32(&rk3399_grf->iomux_pwm_0, IOMUX_PWM_0); /* GPU */
@ -46,31 +48,41 @@ static void init_dvs_outputs(void)
write32(&rk3399_pmugrf->iomux_pwm_3a, IOMUX_PWM_3_A); /* Centerlog */
/*
* Notes:
* Set up voltages for all DVS rails.
*
* design_min = 0.8
* design_max = 1.5
* LITTLE CPU: At the speed we're running at right now and on the
* early silicon, .9V is sane. If/when we run faster, let's bump this.
*
* period = 3333 # 300 kHz
* volt = 1.1
* CENTER LOGIC: There are some claims that this should simply always
* be .9 V. There are other claims that say that we need to adjust this
* dynamically depending on the memory frequency. Until this is sorted
* out, it appears that .9 V works for the 800 MHz.
*
* # Intentionally round down (higher volt) to be safe.
* int((period / (design_max - design_min)) * (design_max - volt))
* BIG CPU / GPU: These aren't used in coreboot. Init to .9V which is
* supposed to be a good default.
*
* Tested on kevin rev0 board 82 w/ all 4 PWMs:
* Details:
* design_min = 0.8
* design_max = 1.5
* period = 3337 # 300 kHz
* volt = 1.1
* # Intentionally round down (higher volt) to be safe.
* int((period / (design_max - design_min)) * (design_max - volt))
*
* period = 3333, volt = 1.1: 1904 -- Worked for me!
* period = 3333, volt = 1.0: 2380 -- Bad
* period = 3333, volt = 0.9: 2856 -- Bad
*
* period = 25000, volt = 1.1: 14285 -- Bad
* period = 25000, volt = 1.0: 17857 -- Bad
*
* TODO: Almost certainly we don't need all 4 PWMs set to the same
* thing. We should experiment
* Apparently a period of 3333 is determined by EEs to be ideal for our
* board design / resistors / capacitors / regulators but due to
* clock dividers we actually get 3337. Solving, we get:
* period = 3337, volt = 1.1: 1906
* period = 3337, volt = 1.0: 2383
* period = 3337, volt = 0.9: 2860
*/
if (IS_ENABLED(CONFIG_BOARD_GOOGLE_KEVIN) && (board_id() <= 2))
duty_ns = 1906; /* 1.1v */
else
duty_ns = 2860; /* 0.9v */
for (i = 0; i < 4; i++)
pwm_init(i, 3333, 1904);
pwm_init(i, 3337, duty_ns);
}
static void prepare_usb(void)