From c6d46248cd15f519e83398aef433884238f93c36 Mon Sep 17 00:00:00 2001 From: Lukasz Luba Date: Wed, 21 Aug 2019 12:42:59 +0200 Subject: [PATCH] dt-bindings: memory-controllers: Add Exynos5422 DMC device description Add device tree bindings for a new Exynos5422 Dynamic Memory Controller device. Signed-off-by: Lukasz Luba Reviewed-by: Rob Herring Signed-off-by: Krzysztof Kozlowski --- .../bindings/memory-controllers/exynos5422-dmc.txt | 73 ++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt diff --git a/Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt b/Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt new file mode 100644 index 0000000..02aeb3b --- /dev/null +++ b/Documentation/devicetree/bindings/memory-controllers/exynos5422-dmc.txt @@ -0,0 +1,73 @@ +* 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 and memory frequency. + +Required properties for DMC device for Exynos5422: +- compatible: Should be "samsung,exynos5422-dmc". +- clocks : list of clock specifiers, must contain an entry for each + required entry in clock-names for CLK_FOUT_SPLL, CLK_MOUT_SCLK_SPLL, + CLK_FF_DOUT_SPLL2, CLK_FOUT_BPLL, CLK_MOUT_BPLL, CLK_SCLK_BPLL, + CLK_MOUT_MX_MSPLL_CCORE, CLK_MOUT_MX_MSPLL_CCORE_PHY, CLK_MOUT_MCLK_CDREX, +- clock-names : should include "fout_spll", "mout_sclk_spll", "ff_dout_spll2", + "fout_bpll", "mout_bpll", "sclk_bpll", "mout_mx_mspll_ccore", + "mout_mclk_cdrex" entries +- devfreq-events : phandles for PPMU devices connected to this DMC. +- vdd-supply : phandle for voltage regulator which is connected. +- reg : registers of two CDREX controllers. +- operating-points-v2 : phandle for OPPs described in v2 definition. +- device-handle : phandle of the connected DRAM memory device. For more + information please refer to documentation file: + Documentation/devicetree/bindings/ddr/lpddr3.txt +- devfreq-events : phandles of the PPMU events used by the controller. +- samsung,syscon-clk : phandle of the clock register set used by the controller, + these registers are used for enabling a 'pause' feature and are not + exposed by clock framework but they must be used in a safe way. + The register offsets are in the driver code and specyfic for this SoC + type. + +Example: + + ppmu_dmc0_0: ppmu@10d00000 { + compatible = "samsung,exynos-ppmu"; + reg = <0x10d00000 0x2000>; + clocks = <&clock CLK_PCLK_PPMU_DREX0_0>; + clock-names = "ppmu"; + events { + ppmu_event_dmc0_0: ppmu-event3-dmc0_0 { + event-name = "ppmu-event3-dmc0_0"; + }; + }; + }; + + dmc: memory-controller@10c20000 { + compatible = "samsung,exynos5422-dmc"; + reg = <0x10c20000 0x100>, <0x10c30000 0x100>, + 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_MCLK_CDREX>, + clock-names = "fout_spll", + "mout_sclk_spll", + "ff_dout_spll2", + "fout_bpll", + "mout_bpll", + "sclk_bpll", + "mout_mx_mspll_ccore", + "mout_mclk_cdrex", + operating-points-v2 = <&dmc_opp_table>; + devfreq-events = <&ppmu_event3_dmc0_0>, <&ppmu_event3_dmc0_1>, + <&ppmu_event3_dmc1_0>, <&ppmu_event3_dmc1_1>; + device-handle = <&samsung_K3QF2F20DB>; + vdd-supply = <&buck1_reg>; + samsung,syscon-clk = <&clock>; + }; -- 2.7.4