[PATCH v5 4/8] dt-bindings: devfreq: add Exynos5422 DMC device description
From: Lukasz Luba
Date: Tue Mar 05 2019 - 05:19:53 EST
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