From 04884b65cc3967245cf4599bc5e9e83811afc45d Mon Sep 17 00:00:00 2001 From: Vadim Bendebury Date: Tue, 12 Apr 2016 16:06:31 -0700 Subject: rockchip/rk3399: Set all 4 DVFS voltage rails to 1.1V @300kHz Previous code had several problems: * It was only initting 3 of the 4 voltage rails hooked up to PWM regulators. * It was using a PWM frequency that was out of range. Apparently from testing 300kHz is best. * It was initting all rails to .9V. On my Kevin I needed 1.1V to make booting all 6 cores / rebooting reliable. With this fix both booting all 6 cores in the kernel is reliable (if we tell the kernel not to touch the PWM) and the "reboot" command from Linux userspace is also reliable (previously it crashed in coreboot). NOTES: * Setting all rails to the same voltage doesn't make a lot of sense. We should figure out what these should _actually_ be. Presumably the little CPU rail can be lower, at least. ...and we don't use the GPU in the BIOS so we should set that lower. BRANCH=none BUG=chrome-os-partner:51922 TEST=reboot test Change-Id: I44f6394e43d291cccf3795ad73ee5b21bd949766 Signed-off-by: Patrick Georgi Original-Commit-Id: 0ac79a7cfb079d23c9d7c4899fdf18c87d05ed0e Original-Change-Id: I80996adefd8542d53ecce59e5233c553700b309f Original-Signed-off-by: Douglas Anderson Original-Signed-off-by: Vadim Bendebury Original-Reviewed-on: https://chromium-review.googlesource.com/339151 Reviewed-on: https://review.coreboot.org/14727 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer --- src/soc/rockchip/rk3399/romstage.c | 44 +++++++++++++++++++++++++++++++++++++- 1 file changed, 43 insertions(+), 1 deletion(-) (limited to 'src/soc/rockchip/rk3399') diff --git a/src/soc/rockchip/rk3399/romstage.c b/src/soc/rockchip/rk3399/romstage.c index 05c853eb84..f22b8c9116 100644 --- a/src/soc/rockchip/rk3399/romstage.c +++ b/src/soc/rockchip/rk3399/romstage.c @@ -24,19 +24,61 @@ #include #include #include -#include #include +#include #include +#include #include +#include static const uint64_t dram_size = (uint64_t)min((uint64_t)CONFIG_DRAM_SIZE_MB * MiB, MAX_DRAM_ADDRESS); +static void init_dvs_outputs(void) +{ + uint32_t i; + + write32(&rk3399_grf->iomux_pwm_0, IOMUX_PWM_0); /* GPU */ + write32(&rk3399_grf->iomux_pwm_1, IOMUX_PWM_1); /* Big */ + write32(&rk3399_pmugrf->iomux_pwm_2, IOMUX_PWM_2); /* Little */ + write32(&rk3399_pmugrf->iomux_pwm_3a, IOMUX_PWM_3_A); /* Centerlog */ + + /* + * Notes: + * + * design_min = 0.8 + * design_max = 1.5 + * + * period = 3333 # 300 kHz + * volt = 1.1 + * + * # Intentionally round down (higher volt) to be safe. + * int((period / (design_max - design_min)) * (design_max - volt)) + * + * Tested on kevin rev0 board 82 w/ all 4 PWMs: + * + * 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 + */ + for (i = 0; i < 4; i++) + pwm_init(i, 3333, 1904); +} + void main(void) { console_init(); exception_init(); + /* Init DVS to conservative values. */ + init_dvs_outputs(); + sdram_init(get_sdram_config()); mmu_config_range((void *)0, (uintptr_t)dram_size, CACHED_MEM); -- cgit v1.2.3