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. + +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>; + }; + }; + -- 2.7.4