dt-bindings: memory: tegra20: emc: Convert to schema

Convert Tegra20 External Memory Controller binding to schema.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210510212320.3255-1-digetx@gmail.comSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.txt

-Embedded Memory Controller
-
-Properties:
-- name : Should be emc
-- #address-cells : Should be 1
-- #size-cells : Should be 0
-- compatible : Should contain "nvidia,tegra20-emc".
-- reg : Offset and length of the register set for the device
-- nvidia,use-ram-code : If present, the sub-nodes will be addressed
-  and chosen using the ramcode board selector. If omitted, only one
-  set of tables can be present and said tables will be used
-  irrespective of ram-code configuration.
-- interrupts : Should contain EMC General interrupt.
-- clocks : Should contain EMC clock.
-- nvidia,memory-controller : Phandle of the Memory Controller node.
-- #interconnect-cells : Should be 0.
-- operating-points-v2: See ../bindings/opp/opp.txt for details.
-
-For each opp entry in 'operating-points-v2' table:
-- opp-supported-hw: One bitfield indicating SoC process ID mask
-
-	A bitwise AND is performed against this value and if any bit
-	matches, the OPP gets enabled.
-
-Optional properties:
-- power-domains: Phandle of the SoC "core" power domain.
-
-Child device nodes describe the memory settings for different configurations and clock rates.
-
-Example:
-
-	opp_table: opp-table {
-		compatible = "operating-points-v2";
-
-		opp@36000000 {
-			opp-microvolt = <950000 950000 1300000>;
-			opp-hz = /bits/ 64 <36000000>;
-		};
-		...
-	};
-
-	memory-controller@7000f400 {
-		#address-cells = < 1 >;
-		#size-cells = < 0 >;
-		#interconnect-cells = <0>;
-		compatible = "nvidia,tegra20-emc";
-		reg = <0x7000f400 0x400>;
-		interrupts = <0 78 0x04>;
-		clocks = <&tegra_car TEGRA20_CLK_EMC>;
-		nvidia,memory-controller = <&mc>;
-		power-domains = <&domain>;
-		operating-points-v2 = <&opp_table>;
-	}
-
-
-Embedded Memory Controller ram-code table
-
-If the emc node has the nvidia,use-ram-code property present, then the
-next level of nodes below the emc table are used to specify which settings
-apply for which ram-code settings.
-
-If the emc node lacks the nvidia,use-ram-code property, this level is omitted
-and the tables are stored directly under the emc node (see below).
-
-Properties:
-
-- name : Should be emc-tables
-- nvidia,ram-code : the binary representation of the ram-code board strappings
-  for which this node (and children) are valid.
-
-
-
-Embedded Memory Controller configuration table
-
-This is a table containing the EMC register settings for the various
-operating speeds of the memory controller. They are always located as
-subnodes of the emc controller node.
-
-There are two ways of specifying which tables to use:
-
-* The simplest is if there is just one set of tables in the device tree,
-  and they will always be used (based on which frequency is used).
-  This is the preferred method, especially when firmware can fill in
-  this information based on the specific system information and just
-  pass it on to the kernel.
-
-* The slightly more complex one is when more than one memory configuration
-  might exist on the system.  The Tegra20 platform handles this during
-  early boot by selecting one out of possible 4 memory settings based
-  on a 2-pin "ram code" bootstrap setting on the board. The values of
-  these strappings can be read through a register in the SoC, and thus
-  used to select which tables to use.
-
-Properties:
-- name : Should be emc-table
-- compatible : Should contain "nvidia,tegra20-emc-table".
-- reg : either an opaque enumerator to tell different tables apart, or
-  the valid frequency for which the table should be used (in kHz).
-- clock-frequency : the clock frequency for the EMC at which this
-  table should be used (in kHz).
-- nvidia,emc-registers : a 46 word array of EMC registers to be programmed
-  for operation at the 'clock-frequency' setting.
-  The order and contents of the registers are:
-    RC, RFC, RAS, RP, R2W, W2R, R2P, W2P, RD_RCD, WR_RCD, RRD, REXT,
-    WDV, QUSE, QRST, QSAFE, RDV, REFRESH, BURST_REFRESH_NUM, PDEX2WR,
-    PDEX2RD, PCHG2PDEN, ACT2PDEN, AR2PDEN, RW2PDEN, TXSR, TCKE, TFAW,
-    TRPAB, TCLKSTABLE, TCLKSTOP, TREFBW, QUSE_EXTRA, FBIO_CFG6, ODT_WRITE,
-    ODT_READ, FBIO_CFG5, CFG_DIG_DLL, DLL_XFORM_DQS, DLL_XFORM_QUSE,
-    ZCAL_REF_CNT, ZCAL_WAIT_CNT, AUTO_CAL_INTERVAL, CFG_CLKTRIM_0,
-    CFG_CLKTRIM_1, CFG_CLKTRIM_2
-
-		emc-table@166000 {
-			reg = <166000>;
-			compatible = "nvidia,tegra20-emc-table";
-			clock-frequency = < 166000 >;
-			nvidia,emc-registers = < 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-						 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-						 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-						 0 0 0 0 >;
-		};
-
-		emc-table@333000 {
-			reg = <333000>;
-			compatible = "nvidia,tegra20-emc-table";
-			clock-frequency = < 333000 >;
-			nvidia,emc-registers = < 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-						 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-						 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-						 0 0 0 0 >;
-		};

Documentation/devicetree/bindings/memory-controllers/nvidia,tegra20-emc.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/nvidia,tegra20-emc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NVIDIA Tegra20 SoC External Memory Controller
+
+maintainers:
+  - Dmitry Osipenko <digetx@gmail.com>
+  - Jon Hunter <jonathanh@nvidia.com>
+  - Thierry Reding <thierry.reding@gmail.com>
+
+description: |
+  The External Memory Controller (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. Tegra20 EMC supports multiple JEDEC
+  standard protocols: DDR1, LPDDR2 and DDR2.
+
+properties:
+  compatible:
+    const: nvidia,tegra20-emc
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  "#interconnect-cells":
+    const: 0
+
+  nvidia,memory-controller:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      Phandle of the Memory Controller node.
+
+  power-domains:
+    maxItems: 1
+    description:
+      Phandle of the SoC "core" power domain.
+
+  operating-points-v2:
+    description:
+      Should contain freqs and voltages and opp-supported-hw property, which
+      is a bitfield indicating SoC process ID mask.
+
+  nvidia,use-ram-code:
+    type: boolean
+    description:
+      If present, the emc-tables@ sub-nodes will be addressed.
+
+$defs:
+  emc-table:
+    type: object
+    properties:
+      compatible:
+        const: nvidia,tegra20-emc-table
+
+      clock-frequency:
+        description:
+          Memory clock rate in kHz.
+        minimum: 1000
+        maximum: 900000
+
+      reg:
+        maxItems: 1
+        description:
+          Either an opaque enumerator to tell different tables apart, or
+          the valid frequency for which the table should be used (in kHz).
+
+      nvidia,emc-registers:
+        description:
+          EMC timing characterization data. These are the registers
+          (see section "15.4.1 EMC Registers" in the TRM) whose values
+          need to be specified, according to the board documentation.
+        $ref: /schemas/types.yaml#/definitions/uint32-array
+        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_WDV
+          - description: EMC_QUSE
+          - description: EMC_QRST
+          - description: EMC_QSAFE
+          - description: EMC_RDV
+          - description: EMC_REFRESH
+          - description: EMC_BURST_REFRESH_NUM
+          - description: EMC_PDEX2WR
+          - description: EMC_PDEX2RD
+          - description: EMC_PCHG2PDEN
+          - description: EMC_ACT2PDEN
+          - description: EMC_AR2PDEN
+          - description: EMC_RW2PDEN
+          - description: EMC_TXSR
+          - 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_DLL_XFORM_DQS
+          - description: EMC_DLL_XFORM_QUSE
+          - description: EMC_ZCAL_REF_CNT
+          - description: EMC_ZCAL_WAIT_CNT
+          - description: EMC_AUTO_CAL_INTERVAL
+          - description: EMC_CFG_CLKTRIM_0
+          - description: EMC_CFG_CLKTRIM_1
+          - description: EMC_CFG_CLKTRIM_2
+
+    required:
+      - clock-frequency
+      - compatible
+      - reg
+      - nvidia,emc-registers
+
+    additionalProperties: false
+
+patternProperties:
+  "^emc-table@[0-9]+$":
+    $ref: "#/$defs/emc-table"
+
+  "^emc-tables@[a-z0-9-]+$":
+    type: object
+    properties:
+      reg:
+        maxItems: 1
+        description:
+          An opaque enumerator to tell different tables apart.
+
+      nvidia,ram-code:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description:
+          Value of RAM_CODE this timing set is used for.
+
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0
+
+    patternProperties:
+      "^emc-table@[0-9]+$":
+        $ref: "#/$defs/emc-table"
+
+    required:
+      - nvidia,ram-code
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - nvidia,memory-controller
+  - "#interconnect-cells"
+  - operating-points-v2
+
+additionalProperties: false
+
+examples:
+  - |
+    external-memory-controller@7000f400 {
+        compatible = "nvidia,tegra20-emc";
+        reg = <0x7000f400 0x400>;
+        interrupts = <0 78 4>;
+        clocks = <&clock_controller 57>;
+
+        nvidia,memory-controller = <&mc>;
+        operating-points-v2 = <&dvfs_opp_table>;
+        power-domains = <&domain>;
+
+        #interconnect-cells = <0>;
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        nvidia,use-ram-code;
+
+        emc-tables@0 {
+            nvidia,ram-code = <0>;
+            reg = <0>;
+
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            emc-table@333000 {
+                reg = <333000>;
+                compatible = "nvidia,tegra20-emc-table";
+                clock-frequency = <333000>;
+                nvidia,emc-registers = <0x00000018 0x00000033
+                        0x00000012 0x00000004 0x00000004 0x00000005
+                        0x00000003 0x0000000c 0x00000006 0x00000006
+                        0x00000003 0x00000001 0x00000004 0x00000005
+                        0x00000004 0x00000009 0x0000000d 0x00000bff
+                        0x00000000 0x00000003 0x00000003 0x00000006
+                        0x00000006 0x00000001 0x00000011 0x000000c8
+                        0x00000003 0x0000000e 0x00000007 0x00000008
+                        0x00000002 0x00000000 0x00000000 0x00000002
+                        0x00000000 0x00000000 0x00000083 0xf0440303
+                        0x007fe010 0x00001414 0x00000000 0x00000000
+                        0x00000000 0x00000000 0x00000000 0x00000000>;
+            };
+        };
+    };