dt-bindings: memory: Add binding for NVIDIA Tegra30 Memory Controller

Add binding for the NVIDIA Tegra30 SoC Memory Controller.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

Documentation/devicetree/bindings/memory-controllers/nvidia,tegra30-mc.yaml

+# SPDX-License-Identifier: (GPL-2.0)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/nvidia,tegra30-mc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVIDIA Tegra30 SoC Memory Controller
+
+maintainers:
+  - Dmitry Osipenko <digetx@gmail.com>
+  - Jon Hunter <jonathanh@nvidia.com>
+  - Thierry Reding <thierry.reding@gmail.com>
+
+description: |
+  Tegra30 Memory Controller architecturally consists of the following parts:
+
+    Arbitration Domains, which can handle a single request or response per
+    clock from a group of clients. Typically, a system has a single Arbitration
+    Domain, but an implementation may divide the client space into multiple
+    Arbitration Domains to increase the effective system bandwidth.
+
+    Protocol Arbiter, which manage a related pool of memory devices. A system
+    may have a single Protocol Arbiter or multiple Protocol Arbiters.
+
+    Memory Crossbar, which routes request and responses between Arbitration
+    Domains and Protocol Arbiters. In the simplest version of the system, the
+    Memory Crossbar is just a pass through between a single Arbitration Domain
+    and a single Protocol Arbiter.
+
+    Global Resources, which include things like configuration registers which
+    are shared across the Memory Subsystem.
+
+  The Tegra30 Memory Controller handles memory requests from internal clients
+  and arbitrates among them to allocate memory bandwidth for DDR3L and LPDDR2
+  SDRAMs.
+
+properties:
+  compatible:
+    const: nvidia,tegra30-mc
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: mc
+
+  interrupts:
+    maxItems: 1
+
+  "#reset-cells":
+    const: 1
+
+  "#iommu-cells":
+    const: 1
+
+patternProperties:
+  "^emc-timings-[0-9]+$":
+    type: object
+    properties:
+      nvidia,ram-code:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description:
+          Value of RAM_CODE this timing set is used for.
+
+    patternProperties:
+      "^timing-[0-9]+$":
+        type: object
+        properties:
+          clock-frequency:
+            description:
+              Memory clock rate in Hz.
+            minimum: 1000000
+            maximum: 900000000
+
+          nvidia,emem-configuration:
+            $ref: /schemas/types.yaml#/definitions/uint32-array
+            description: |
+              Values to be written to the EMEM register block. See section
+              "18.13.1 MC Registers" in the TRM.
+            items:
+              - description: MC_EMEM_ARB_CFG
+              - description: MC_EMEM_ARB_OUTSTANDING_REQ
+              - description: MC_EMEM_ARB_TIMING_RCD
+              - description: MC_EMEM_ARB_TIMING_RP
+              - description: MC_EMEM_ARB_TIMING_RC
+              - description: MC_EMEM_ARB_TIMING_RAS
+              - description: MC_EMEM_ARB_TIMING_FAW
+              - description: MC_EMEM_ARB_TIMING_RRD
+              - description: MC_EMEM_ARB_TIMING_RAP2PRE
+              - description: MC_EMEM_ARB_TIMING_WAP2PRE
+              - description: MC_EMEM_ARB_TIMING_R2R
+              - description: MC_EMEM_ARB_TIMING_W2W
+              - description: MC_EMEM_ARB_TIMING_R2W
+              - description: MC_EMEM_ARB_TIMING_W2R
+              - description: MC_EMEM_ARB_DA_TURNS
+              - description: MC_EMEM_ARB_DA_COVERS
+              - description: MC_EMEM_ARB_MISC0
+              - description: MC_EMEM_ARB_RING1_THROTTLE
+
+        required:
+          - clock-frequency
+          - nvidia,emem-configuration
+
+        additionalProperties: false
+
+    required:
+      - nvidia,ram-code
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+  - "#reset-cells"
+  - "#iommu-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    memory-controller@7000f000 {
+        compatible = "nvidia,tegra30-mc";
+        reg = <0x7000f000 0x400>;
+        clocks = <&tegra_car 32>;
+        clock-names = "mc";
+
+        interrupts = <0 77 4>;
+
+        #iommu-cells = <1>;
+        #reset-cells = <1>;
+
+        emc-timings-1 {
+            nvidia,ram-code = <1>;
+
+            timing-667000000 {
+                clock-frequency = <667000000>;
+
+                nvidia,emem-configuration = <
+                    0x0000000a /* MC_EMEM_ARB_CFG */
+                    0xc0000079 /* MC_EMEM_ARB_OUTSTANDING_REQ */
+                    0x00000003 /* MC_EMEM_ARB_TIMING_RCD */
+                    0x00000004 /* MC_EMEM_ARB_TIMING_RP */
+                    0x00000010 /* MC_EMEM_ARB_TIMING_RC */
+                    0x0000000b /* MC_EMEM_ARB_TIMING_RAS */
+                    0x0000000a /* MC_EMEM_ARB_TIMING_FAW */
+                    0x00000001 /* MC_EMEM_ARB_TIMING_RRD */
+                    0x00000003 /* MC_EMEM_ARB_TIMING_RAP2PRE */
+                    0x0000000b /* MC_EMEM_ARB_TIMING_WAP2PRE */
+                    0x00000002 /* MC_EMEM_ARB_TIMING_R2R */
+                    0x00000002 /* MC_EMEM_ARB_TIMING_W2W */
+                    0x00000004 /* MC_EMEM_ARB_TIMING_R2W */
+                    0x00000008 /* MC_EMEM_ARB_TIMING_W2R */
+                    0x08040202 /* MC_EMEM_ARB_DA_TURNS */
+                    0x00130b10 /* MC_EMEM_ARB_DA_COVERS */
+                    0x70ea1f11 /* MC_EMEM_ARB_MISC0 */
+                    0x001f0000 /* MC_EMEM_ARB_RING1_THROTTLE */
+                >;
+            };
+        };
+    };