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

Add device-tree binding for NVIDIA Tegra30 External Memory Controller.
The binding is based on the Tegra124 EMC binding since hardware is
similar, although there are couple significant differences.

Note that the memory timing description is given in a platform-specific
form because there is no detailed information on how to convert a
typical-common DDR timing into the register values. The timing format is
borrowed from downstream kernel, hence there is no hurdle in regards to
upstreaming of memory timings for the boards.
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
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-emc.yaml

+# SPDX-License-Identifier: (GPL-2.0)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/nvidia,tegra30-emc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVIDIA Tegra30 SoC External Memory Controller
+
+maintainers:
+  - Dmitry Osipenko <digetx@gmail.com>
+  - Jon Hunter <jonathanh@nvidia.com>
+  - Thierry Reding <thierry.reding@gmail.com>
+
+description: |
+  The EMC interfaces with the off-chip SDRAM to service the request stream
+  sent from Memory Controller. The EMC also has various performance-affecting
+  settings beyond the obvious SDRAM configuration parameters and initialization
+  settings. Tegra30 EMC supports multiple JEDEC standard protocols: LPDDR2,
+  LPDDR3, and DDR3.
+
+properties:
+  compatible:
+    const: nvidia,tegra30-emc
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  nvidia,memory-controller:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      Phandle of the Memory Controller node.
+
+patternProperties:
+  "^emc-timings-[0-9]+$":
+    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,emc-auto-cal-interval:
+            $ref: /schemas/types.yaml#/definitions/uint32
+            description:
+              Pad calibration interval in microseconds.
+            minimum: 0
+            maximum: 2097151
+
+          nvidia,emc-mode-1:
+            $ref: /schemas/types.yaml#/definitions/uint32
+            description:
+              Mode Register 1.
+
+          nvidia,emc-mode-2:
+            $ref: /schemas/types.yaml#/definitions/uint32
+            description:
+              Mode Register 2.
+
+          nvidia,emc-mode-reset:
+            $ref: /schemas/types.yaml#/definitions/uint32
+            description:
+              Mode Register 0.
+
+          nvidia,emc-zcal-cnt-long:
+            $ref: /schemas/types.yaml#/definitions/uint32
+            description:
+              Number of EMC clocks to wait before issuing any commands after
+              sending ZCAL_MRW_CMD.
+            minimum: 0
+            maximum: 1023
+
+          nvidia,emc-cfg-dyn-self-ref:
+            type: boolean
+            description:
+              Dynamic self-refresh enabled.
+
+          nvidia,emc-cfg-periodic-qrst:
+            type: boolean
+            description:
+              FBIO "read" FIFO periodic resetting enabled.
+
+          nvidia,emc-configuration:
+            $ref: /schemas/types.yaml#/definitions/uint32-array
+            description:
+              EMC timing characterization data. These are the registers
+              (see section "18.13.2 EMC Registers" in the TRM) whose values
+              need to be specified, according to the board documentation.
+            items:
+              - description: EMC_RC
+              - description: EMC_RFC
+              - description: EMC_RAS
+              - description: EMC_RP
+              - description: EMC_R2W
+              - description: EMC_W2R
+              - description: EMC_R2P
+              - description: EMC_W2P
+              - description: EMC_RD_RCD
+              - description: EMC_WR_RCD
+              - description: EMC_RRD
+              - description: EMC_REXT
+              - description: EMC_WEXT
+              - description: EMC_WDV
+              - description: EMC_QUSE
+              - description: EMC_QRST
+              - description: EMC_QSAFE
+              - description: EMC_RDV
+              - description: EMC_REFRESH
+              - description: EMC_BURST_REFRESH_NUM
+              - description: EMC_PRE_REFRESH_REQ_CNT
+              - description: EMC_PDEX2WR
+              - description: EMC_PDEX2RD
+              - description: EMC_PCHG2PDEN
+              - description: EMC_ACT2PDEN
+              - description: EMC_AR2PDEN
+              - description: EMC_RW2PDEN
+              - description: EMC_TXSR
+              - description: EMC_TXSRDLL
+              - description: EMC_TCKE
+              - description: EMC_TFAW
+              - description: EMC_TRPAB
+              - description: EMC_TCLKSTABLE
+              - description: EMC_TCLKSTOP
+              - description: EMC_TREFBW
+              - description: EMC_QUSE_EXTRA
+              - description: EMC_FBIO_CFG6
+              - description: EMC_ODT_WRITE
+              - description: EMC_ODT_READ
+              - description: EMC_FBIO_CFG5
+              - description: EMC_CFG_DIG_DLL
+              - description: EMC_CFG_DIG_DLL_PERIOD
+              - description: EMC_DLL_XFORM_DQS0
+              - description: EMC_DLL_XFORM_DQS1
+              - description: EMC_DLL_XFORM_DQS2
+              - description: EMC_DLL_XFORM_DQS3
+              - description: EMC_DLL_XFORM_DQS4
+              - description: EMC_DLL_XFORM_DQS5
+              - description: EMC_DLL_XFORM_DQS6
+              - description: EMC_DLL_XFORM_DQS7
+              - description: EMC_DLL_XFORM_QUSE0
+              - description: EMC_DLL_XFORM_QUSE1
+              - description: EMC_DLL_XFORM_QUSE2
+              - description: EMC_DLL_XFORM_QUSE3
+              - description: EMC_DLL_XFORM_QUSE4
+              - description: EMC_DLL_XFORM_QUSE5
+              - description: EMC_DLL_XFORM_QUSE6
+              - description: EMC_DLL_XFORM_QUSE7
+              - description: EMC_DLI_TRIM_TXDQS0
+              - description: EMC_DLI_TRIM_TXDQS1
+              - description: EMC_DLI_TRIM_TXDQS2
+              - description: EMC_DLI_TRIM_TXDQS3
+              - description: EMC_DLI_TRIM_TXDQS4
+              - description: EMC_DLI_TRIM_TXDQS5
+              - description: EMC_DLI_TRIM_TXDQS6
+              - description: EMC_DLI_TRIM_TXDQS7
+              - description: EMC_DLL_XFORM_DQ0
+              - description: EMC_DLL_XFORM_DQ1
+              - description: EMC_DLL_XFORM_DQ2
+              - description: EMC_DLL_XFORM_DQ3
+              - description: EMC_XM2CMDPADCTRL
+              - description: EMC_XM2DQSPADCTRL2
+              - description: EMC_XM2DQPADCTRL2
+              - description: EMC_XM2CLKPADCTRL
+              - description: EMC_XM2COMPPADCTRL
+              - description: EMC_XM2VTTGENPADCTRL
+              - description: EMC_XM2VTTGENPADCTRL2
+              - description: EMC_XM2QUSEPADCTRL
+              - description: EMC_XM2DQSPADCTRL3
+              - description: EMC_CTT_TERM_CTRL
+              - description: EMC_ZCAL_INTERVAL
+              - description: EMC_ZCAL_WAIT_CNT
+              - description: EMC_MRS_WAIT_CNT
+              - description: EMC_AUTO_CAL_CONFIG
+              - description: EMC_CTT
+              - description: EMC_CTT_DURATION
+              - description: EMC_DYN_SELF_REF_CONTROL
+              - description: EMC_FBIO_SPARE
+              - description: EMC_CFG_RSV
+
+        required:
+          - clock-frequency
+          - nvidia,emc-auto-cal-interval
+          - nvidia,emc-mode-1
+          - nvidia,emc-mode-2
+          - nvidia,emc-mode-reset
+          - nvidia,emc-zcal-cnt-long
+          - nvidia,emc-configuration
+
+        additionalProperties: false
+
+    required:
+      - nvidia,ram-code
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - nvidia,memory-controller
+
+additionalProperties: false
+
+examples:
+  - |
+    external-memory-controller@7000f400 {
+        compatible = "nvidia,tegra30-emc";
+        reg = <0x7000f400 0x400>;
+        interrupts = <0 78 4>;
+        clocks = <&tegra_car 57>;
+
+        nvidia,memory-controller = <&mc>;
+
+        emc-timings-1 {
+            nvidia,ram-code = <1>;
+
+            timing-667000000 {
+                clock-frequency = <667000000>;
+
+                nvidia,emc-auto-cal-interval = <0x001fffff>;
+                nvidia,emc-mode-1 = <0x80100002>;
+                nvidia,emc-mode-2 = <0x80200018>;
+                nvidia,emc-mode-reset = <0x80000b71>;
+                nvidia,emc-zcal-cnt-long = <0x00000040>;
+                nvidia,emc-cfg-periodic-qrst;
+
+                nvidia,emc-configuration = <
+                    0x00000020 /* EMC_RC */
+                    0x0000006a /* EMC_RFC */
+                    0x00000017 /* EMC_RAS */
+                    0x00000007 /* EMC_RP */
+                    0x00000005 /* EMC_R2W */
+                    0x0000000c /* EMC_W2R */
+                    0x00000003 /* EMC_R2P */
+                    0x00000011 /* EMC_W2P */
+                    0x00000007 /* EMC_RD_RCD */
+                    0x00000007 /* EMC_WR_RCD */
+                    0x00000002 /* EMC_RRD */
+                    0x00000001 /* EMC_REXT */
+                    0x00000000 /* EMC_WEXT */
+                    0x00000007 /* EMC_WDV */
+                    0x0000000a /* EMC_QUSE */
+                    0x00000009 /* EMC_QRST */
+                    0x0000000b /* EMC_QSAFE */
+                    0x00000011 /* EMC_RDV */
+                    0x00001412 /* EMC_REFRESH */
+                    0x00000000 /* EMC_BURST_REFRESH_NUM */
+                    0x00000504 /* EMC_PRE_REFRESH_REQ_CNT */
+                    0x00000002 /* EMC_PDEX2WR */
+                    0x0000000e /* EMC_PDEX2RD */
+                    0x00000001 /* EMC_PCHG2PDEN */
+                    0x00000000 /* EMC_ACT2PDEN */
+                    0x0000000c /* EMC_AR2PDEN */
+                    0x00000016 /* EMC_RW2PDEN */
+                    0x00000072 /* EMC_TXSR */
+                    0x00000200 /* EMC_TXSRDLL */
+                    0x00000005 /* EMC_TCKE */
+                    0x00000015 /* EMC_TFAW */
+                    0x00000000 /* EMC_TRPAB */
+                    0x00000006 /* EMC_TCLKSTABLE */
+                    0x00000007 /* EMC_TCLKSTOP */
+                    0x00001453 /* EMC_TREFBW */
+                    0x0000000b /* EMC_QUSE_EXTRA */
+                    0x00000006 /* EMC_FBIO_CFG6 */
+                    0x00000000 /* EMC_ODT_WRITE */
+                    0x00000000 /* EMC_ODT_READ */
+                    0x00005088 /* EMC_FBIO_CFG5 */
+                    0xf00b0191 /* EMC_CFG_DIG_DLL */
+                    0x00008000 /* EMC_CFG_DIG_DLL_PERIOD */
+                    0x00000008 /* EMC_DLL_XFORM_DQS0 */
+                    0x00000008 /* EMC_DLL_XFORM_DQS1 */
+                    0x00000008 /* EMC_DLL_XFORM_DQS2 */
+                    0x00000008 /* EMC_DLL_XFORM_DQS3 */
+                    0x0000000a /* EMC_DLL_XFORM_DQS4 */
+                    0x0000000a /* EMC_DLL_XFORM_DQS5 */
+                    0x0000000a /* EMC_DLL_XFORM_DQS6 */
+                    0x0000000a /* EMC_DLL_XFORM_DQS7 */
+                    0x00018000 /* EMC_DLL_XFORM_QUSE0 */
+                    0x00018000 /* EMC_DLL_XFORM_QUSE1 */
+                    0x00018000 /* EMC_DLL_XFORM_QUSE2 */
+                    0x00018000 /* EMC_DLL_XFORM_QUSE3 */
+                    0x00000000 /* EMC_DLL_XFORM_QUSE4 */
+                    0x00000000 /* EMC_DLL_XFORM_QUSE5 */
+                    0x00000000 /* EMC_DLL_XFORM_QUSE6 */
+                    0x00000000 /* EMC_DLL_XFORM_QUSE7 */
+                    0x00000000 /* EMC_DLI_TRIM_TXDQS0 */
+                    0x00000000 /* EMC_DLI_TRIM_TXDQS1 */
+                    0x00000000 /* EMC_DLI_TRIM_TXDQS2 */
+                    0x00000000 /* EMC_DLI_TRIM_TXDQS3 */
+                    0x00000000 /* EMC_DLI_TRIM_TXDQS4 */
+                    0x00000000 /* EMC_DLI_TRIM_TXDQS5 */
+                    0x00000000 /* EMC_DLI_TRIM_TXDQS6 */
+                    0x00000000 /* EMC_DLI_TRIM_TXDQS7 */
+                    0x0000000a /* EMC_DLL_XFORM_DQ0 */
+                    0x0000000a /* EMC_DLL_XFORM_DQ1 */
+                    0x0000000a /* EMC_DLL_XFORM_DQ2 */
+                    0x0000000a /* EMC_DLL_XFORM_DQ3 */
+                    0x000002a0 /* EMC_XM2CMDPADCTRL */
+                    0x0800013d /* EMC_XM2DQSPADCTRL2 */
+                    0x22220000 /* EMC_XM2DQPADCTRL2 */
+                    0x77fff884 /* EMC_XM2CLKPADCTRL */
+                    0x01f1f501 /* EMC_XM2COMPPADCTRL */
+                    0x07077404 /* EMC_XM2VTTGENPADCTRL */
+                    0x54000000 /* EMC_XM2VTTGENPADCTRL2 */
+                    0x080001e8 /* EMC_XM2QUSEPADCTRL */
+                    0x0c000021 /* EMC_XM2DQSPADCTRL3 */
+                    0x00000802 /* EMC_CTT_TERM_CTRL */
+                    0x00020000 /* EMC_ZCAL_INTERVAL */
+                    0x00000100 /* EMC_ZCAL_WAIT_CNT */
+                    0x0155000c /* EMC_MRS_WAIT_CNT */
+                    0xa0f10000 /* EMC_AUTO_CAL_CONFIG */
+                    0x00000000 /* EMC_CTT */
+                    0x00000000 /* EMC_CTT_DURATION */
+                    0x800028a5 /* EMC_DYN_SELF_REF_CONTROL */
+                    0xe8000000 /* EMC_FBIO_SPARE */
+                    0xff00ff49 /* EMC_CFG_RSV */
+                >;
+            };
+        };
+    };