Hi Lukasz, On 19. 3. 5. 오후 7:19, Lukasz Luba wrote: > The patch adds description for DT binding for a new Exynos5422 Dynamic > Memory Controller device. > > Signed-off-by: Lukasz Luba <l.luba@xxxxxxxxxxxxxxxxxxx> > --- > .../devicetree/bindings/devfreq/exynos5422-dmc.txt | 177 +++++++++++++++++++++ > 1 file changed, 177 insertions(+) > create mode 100644 Documentation/devicetree/bindings/devfreq/exynos5422-dmc.txt > > diff --git a/Documentation/devicetree/bindings/devfreq/exynos5422-dmc.txt b/Documentation/devicetree/bindings/devfreq/exynos5422-dmc.txt > new file mode 100644 > index 0000000..0e73e98 > --- /dev/null > +++ b/Documentation/devicetree/bindings/devfreq/exynos5422-dmc.txt > @@ -0,0 +1,177 @@ > +* Exynos5422 frequency and voltage scaling for Dynamic Memory Controller device > + > +The Samsung Exynos5422 SoC has DMC (Dynamic Memory Controller) to which the DRAM > +memory chips are connected. The driver is to monitor the controller in runtime > +and switch frequency and voltage. To monitor the usage of the controller in > +runtime, the driver uses the PPMU (Platform Performance Monitoring Unit), which > +is able to measure the current load of the memory. > +When 'userspace' governor is used for the driver, an application is able to > +switch the DMC frequency. > + > +Required properties for DMC device for Exynos5422: > +- compatible: Should be "samsung,exynos5422-bus". > +- clock-names : the name of clock used by the bus, "bus". > +- clocks : phandles for clock specified in "clock-names" property. > +- devfreq-events : phandles for PPMU devices connected to this DMC. I already replied with following comments on v4 patch[1]. But, you didn't reply anything. We can reduce the duplicate review by keeping the basic review rule. - Re: [PATCH v4 5/8] dt-bindings: devfreq: add Exynos5422 DMC device description [1] https://do-db2.lkml.org/lkml/2019/2/3/64 [Following comments were replied on v4 patch[1]] > +- compatible: Should be "samsung,exynos5422-bus". The compatible name is wrong. - exynos5422-bus -> exynos5422-dmc > +- clock-names : the name of clock used by the bus, "bus". 'bus' is right? > +- clocks : phandles for clock specified in "clock-names" property. > +- devfreq-events : phandles for PPMU devices connected to this DMC. The dt-binging file doesn't contain the any description for 'reg' properties. > + > +The example definition of a DMC and PPMU devices declared in DT is shown below: > + > + ppmu_dmc0_0: ppmu@10d00000 { > + compatible = "samsung,exynos-ppmu"; > + reg = <0x10d00000 0x2000>; > + clocks = <&clock CLK_PCLK_PPMU_DREX0_0>; > + clock-names = "ppmu"; > + status = "okay"; > + events { > + ppmu_event_dmc0_0: ppmu-event3-dmc0_0 { > + event-name = "ppmu-event3-dmc0_0"; > + }; > + }; > + }; > + > + > + ppmu_dmc0_1: ppmu@10d10000 { > + compatible = "samsung,exynos-ppmu"; > + reg = <0x10d10000 0x2000>; > + clocks = <&clock CLK_PCLK_PPMU_DREX0_1>; > + clock-names = "ppmu"; > + status = "okay"; > + events { > + ppmu_event_dmc0_1: ppmu-event3-dmc0_1 { > + event-name = "ppmu-event3-dmc0_1"; > + }; > + }; > + }; > + > + ppmu_dmc1_0: ppmu@10d10000 { > + compatible = "samsung,exynos-ppmu"; > + reg = <0x10d60000 0x2000>; > + clocks = <&clock CLK_PCLK_PPMU_DREX1_0>; > + clock-names = "ppmu"; > + status = "okay"; > + events { > + ppmu_event_dmc1_0: ppmu-event3-dmc1_0 { > + event-name = "ppmu-event3-dmc1_0"; > + }; > + }; > + }; > + > + ppmu_dmc1_1: ppmu@10d70000 { > + compatible = "samsung,exynos-ppmu"; > + reg = <0x10d70000 0x2000>; > + clocks = <&clock CLK_PCLK_PPMU_DREX1_1>; > + clock-names = "ppmu"; > + status = "okay"; > + events { > + ppmu_event_dmc1_1: ppmu-event3-dmc1_1 { > + event-name = "ppmu-event3-dmc1_1"; > + }; > + }; > + }; > + > + dmc: memory-controller@10c20000 { > + compatible = "samsung,exynos5422-dmc"; > + reg = <0x10c20000 0x10000>, <0x10c30000 0x10000>, > + <0x10000000 0x1000>; > + clocks = <&clock CLK_FOUT_SPLL>, > + <&clock CLK_MOUT_SCLK_SPLL>, > + <&clock CLK_FF_DOUT_SPLL2>, > + <&clock CLK_FOUT_BPLL>, > + <&clock CLK_MOUT_BPLL>, > + <&clock CLK_SCLK_BPLL>, > + <&clock CLK_MOUT_MX_MSPLL_CCORE>, > + <&clock CLK_MOUT_MX_MSPLL_CCORE_PHY>, > + <&clock CLK_MOUT_MCLK_CDREX>, > + <&clock CLK_DOUT_CLK2X_PHY0>, > + <&clock CLK_CLKM_PHY0>, > + <&clock CLK_CLKM_PHY1>, > + <&clock CLK_CDREX_PAUSE>, > + <&clock CLK_CDREX_TIMING_SET>; > + clock-names = "fout_spll", > + "mout_sclk_spll", > + "ff_dout_spll2", > + "fout_bpll", > + "mout_bpll", > + "sclk_bpll", > + "mout_mx_mspll_ccore", > + "mout_mx_mspll_ccore_phy", > + "mout_mclk_cdrex", > + "dout_clk2x_phy0", > + "clkm_phy0", > + "clkm_phy1", > + "clk_cdrex_pause", > + "clk_cdrex_timing_set"; > + status = "okay"; > + operating-points-v2 = <&dmc_opp_table>; > + devfreq-events = <&ppmu_dmc0_0>, <&ppmu_dmc0_1>, > + <&ppmu_dmc1_0>, <&ppmu_dmc1_1>; > + }; > + > +The needed timings of DRAM memory are stored in dedicated nodes. > +There are two nodes with regular timings and for bypass mode. > + > + dmc_bypass_mode: bypass_mode { > + compatible = "samsung,dmc-bypass-mode"; > + > + freq-hz = <400000000>; > + volt-uv = <887500>; > + dram-timing-row = <0x365a9713>; > + dram-timing-data = <0x4740085e>; > + dram-timing-power = <0x543a0446>; > + }; > + > + dram_timing: timing { > + compatible = "samsung,dram-timing"; > + > + dram-timing-names = "165MHz", "206MHz", "275MHz", "413MHz", > + "543MHz", "633MHz", "728MHz", "825MHz"; > + dram-timing-row = <0x11223185>, <0x112331C6>, <0x12244287>, > + <0x1B35538A>, <0x244764CD>, <0x2A48758F>, > + <0x30598651>, <0x365A9713>; > + dram-timing-data = <0x2720085E>, <0x2720085E>, <0x2720085E>, > + <0x2720085E>, <0x3730085E>, <0x3730085E>, > + <0x3730085E>, <0x4740085E>; > + dram-timing-power = <0x140C0225>, <0x180F0225>, <0x1C140225>, > + <0x2C1D0225>, <0x38270335>, <0x402D0335>, > + <0x4C330336>, <0x543A0446>; > + }; > + > +The frequencies supported by the DMC are stored in OPP table v2. > + > + dmc_opp_table: opp_table2 { > + compatible = "operating-points-v2"; > + > + opp00 { > + opp-hz = /bits/ 64 <165000000>; > + opp-microvolt = <875000>; > + }; > + opp01 { > + opp-hz = /bits/ 64 <206000000>; > + opp-microvolt = <875000>; > + }; > + opp02 { > + opp-hz = /bits/ 64 <275000000>; > + opp-microvolt = <875000>; > + }; > + opp03 { > + opp-hz = /bits/ 64 <413000000>; > + opp-microvolt = <887500>; > + }; > + opp04 { > + opp-hz = /bits/ 64 <543000000>; > + opp-microvolt = <937500>; > + }; > + opp05 { > + opp-hz = /bits/ 64 <633000000>; > + opp-microvolt = <1012500>; > + }; > + opp06 { > + opp-hz = /bits/ 64 <728000000>; > + opp-microvolt = <1037500>; > + }; > + opp07 { > + opp-hz = /bits/ 64 <825000000>; > + opp-microvolt = <1050000>; > + }; > + }; > + > -- Best Regards, Chanwoo Choi Samsung Electronics