[PATCH V4 1/8] dt-bindings: memory: tegra: Add external memory controller binding for Tegra210

[Joseph Lo <josephl@nvidia.com>]

Add the binding document for the external memory controller (EMC) which
communicates with external LPDDR4 devices. It includes the bindings of
the EMC node and a sub-node of EMC table which under the reserved memory
node. The EMC table contains the data of the rates that EMC supported.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
---
v4:
- no change
v3:
- drop the bindings of EMC table
- add memory-region and reserved-memory node for EMC table
---
 .../nvidia,tegra210-emc.txt                   | 55 +++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/nvidia,tegra210-emc.txt

diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra210-emc.txt b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra210-emc.txt
new file mode 100644
index 000000000000..d65aeef2329c
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra210-emc.txt
@@ -0,0 +1,55 @@
+NVIDIA Tegra210 SoC EMC (external memory controller)
+====================================================
+
+Device node
+===========
+Required properties :
+- compatible : should be "nvidia,tegra210-emc".
+- reg : physical base address and length of the controller's registers.
+- clocks : phandles of the possible source clocks.
+- clock-names : names of the possible source clocks.
+- interrupts : Should contain the EMC general interrupt.
+- memory-region : phandle to the reserved memory (see
+  Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt) which
+  contains a sub-node of EMC table.
+- nvidia,memory-controller : phandle of the memory controller.
+
+Reserved memory node
+====================
+Should contain a sub-node of EMC table with required properties:
+- compatible : should be "nvidia,tegra210-emc-table".
+- reg : physical address and length of the location of EMC table.
+
+Example:
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		emc_table: emc-table@8be00000 {
+			compatible = "nvidia,tegra210-emc-table";
+			reg = <0x0 0x8be00000 0x0 0x10000>;
+			status = "okay";
+		};
+	};
+
+	external-memory-controller@7001b000 {
+		compatible = "nvidia,tegra210-emc";
+		reg = <0x0 0x7001b000 0x0 0x1000>,
+		      <0x0 0x7001e000 0x0 0x1000>,
+		      <0x0 0x7001f000 0x0 0x1000>;
+		clocks = <&tegra_car TEGRA210_CLK_EMC>,
+			 <&tegra_car TEGRA210_CLK_PLL_M>,
+			 <&tegra_car TEGRA210_CLK_PLL_C>,
+			 <&tegra_car TEGRA210_CLK_PLL_P>,
+			 <&tegra_car TEGRA210_CLK_CLK_M>,
+			 <&tegra_car TEGRA210_CLK_PLL_M_UD>,
+			 <&tegra_car TEGRA210_CLK_PLL_MB_UD>,
+			 <&tegra_car TEGRA210_CLK_PLL_MB>,
+			 <&tegra_car TEGRA210_CLK_PLL_P_UD>;
+		clock-names = "emc", "pll_m", "pll_c", "pll_p", "clk_m",
+			      "pll_m_ud", "pll_mb_ud", "pll_mb", "pll_p_ud";
+		interrupts = <GIC_SPI 78 IRQ_TYPE_LEVEL_HIGH>;
+		memory-region = <&emc_table>;
+		nvidia,memory-controller = <&mc>;
+	};
-- 
2.21.0