Dear all, The rk3399 platform has a DFI controller that can monitor DDR load and a DMC driver that talks with the TF-A (Trusted Firmware-A) to dynamically set the DDR frequency with following flow. kernel Trusted Firmware-A (bl31) monitor ddr load | | get_target_rate | | pass rate to TF-A clk_set_rate(ddr) --------------------->run ddr dvs flow | | <------------------------------end ddr dvs flow | | return These patches add support for devfreq to dynamically control the DDR frequency for the gru chromebooks. By default it uses the 'simple_ondemand' governor which can adjust the frequency based on the DDR load. Waiting for your feedback. Best regards, Gaël Note: The RFC and the first patchset contained three patches to sync the DDR frequency change within the vblank. These patches was removed. Changes in v4: - [PATCH v3 1/5] Add Acked-by: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>. - [PATCH v3 2/5] Add Acked-by: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>. - [PATCH v3 3/5] Add Acked-by: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>. - [PATCH v3 4/5] Remove board related DDR settings (moved to 5/5). - [PATCH v3 5/5] Add board related DDR settings (moved from 5/5). Changes in v3: - [PATCH v2 1/5] Add Signed-off-by: Gaël PORTAY <gael.portay@xxxxxxxxxxxxx>. - [PATCH v2 2/5] Add Signed-off-by: Gaël PORTAY <gael.portay@xxxxxxxxxxxxx>. - [PATCH v2 3/5] Add Signed-off-by: Gaël PORTAY <gael.portay@xxxxxxxxxxxxx>. Remove comments. Move pmu dt parsing after dt-parsing of timings to fix data->odt_dis_freq value. - [PATCH v2 5/5] Remove display_subsystem nodes. Changes in v2: - [PATCH 1/8] Really add Acked-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>. - [PATCH 4/8] Removed from patchset. - [PATCH 5/8] Removed from patchset. - [PATCH 6/8] Removed from patchset. - [PATCH 7/8] Reword the commit message to reflect the removal of rk3390-dram-default-timing.dts in v1. - [PATCH 8/8] Move center-supply attribute of dmc node in file rk3399-gru-chromebook.dtsi (where ppvar_centerlogic is defined). Changes in v1: - [RFC 1/10] Add Acked-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx> - [RFC 1/10] s/Generic/General/ (Robin Murphy) - [RFC 2/10] Add reviewed and acked tags from Chanwoo Choi and Rob Herring - [RFC 3/10] Add an explanation for platform SIP calls. - [RFC 3/10] Change if statement for a switch. - [RFC 3/10] Rename ddr_flag to odt_enable to be more clear. - [RFC 4/10] Removed from the series. I did not found a use case where not holding the mutex causes the issue. - [RFC 7/10] Removed from the series. I did not found a use case where this matters. - [RFC 8/10] Move rk3399-dram.h to dt-includes. - [RFC 8/10] Put sdram default values under the dmc node. - [RFC 8/10] Removed rk3399-dram-default-timing.dts Enric Balletbo i Serra (3): devfreq: rockchip-dfi: Move GRF definitions to a common place. dt-bindings: devfreq: rk3399_dmc: Add rockchip,pmu phandle. devfreq: rk3399_dmc: Pass ODT and auto power down parameters to TF-A. Lin Huang (2): arm64: dts: rk3399: Add dfi and dmc nodes. arm64: dts: rockchip: Enable dmc and dfi nodes on gru. .../bindings/devfreq/rk3399_dmc.txt | 2 + .../dts/rockchip/rk3399-gru-chromebook.dtsi | 4 + arch/arm64/boot/dts/rockchip/rk3399-gru.dtsi | 46 ++++++++++++ .../boot/dts/rockchip/rk3399-op1-opp.dtsi | 29 ++++++++ arch/arm64/boot/dts/rockchip/rk3399.dtsi | 19 +++++ drivers/devfreq/event/rockchip-dfi.c | 23 ++---- drivers/devfreq/rk3399_dmc.c | 71 +++++++++++++++++- include/dt-bindings/power/rk3399-dram.h | 73 +++++++++++++++++++ include/soc/rockchip/rk3399_grf.h | 21 ++++++ include/soc/rockchip/rockchip_sip.h | 1 + 10 files changed, 272 insertions(+), 17 deletions(-) create mode 100644 include/dt-bindings/power/rk3399-dram.h create mode 100644 include/soc/rockchip/rk3399_grf.h -- 2.21.0