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Subject[PATCH v12 4/9] dt-bindings: memory-controllers: add Exynos5422 DMC device description
Date
The patch adds description for DT binding for a new Exynos5422 Dynamic
Memory Controller device.

Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com>
---
.../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 000000000000..02aeb3b5a820
--- /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>;
+ };
--
2.17.1
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