spi: dt-bindings: Introduce qcom,spi-qpic-snand

Document the QPIC-SPI-NAND flash controller present in the IPQ SoCs.
It can work both in serial and parallel mode and supports typical
SPI-NAND page cache operations.

Reviewed-by: Krzysztof Kozlowski <[email protected]>
Reviewed-by: Rob Herring (Arm) <[email protected]>
Signed-off-by: Md Sadre Alam <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

Author: Md Sadre Alam

Documentation/devicetree/bindings/spi/qcom,spi-qpic-snand.yaml

@@ -0,0 +1,83 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/qcom,spi-qpic-snand.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm QPIC NAND controller
+
+maintainers:
+  - Md sadre Alam <[email protected]>
+
+description:
+  The QCOM QPIC-SPI-NAND flash controller is an extended version of
+  the QCOM QPIC NAND flash controller. It can work both in serial
+  and parallel mode. It supports typical SPI-NAND page cache
+  operations in single, dual or quad IO mode with pipelined ECC
+  encoding/decoding using the QPIC ECC HW engine.
+
+allOf:
+  - $ref: /schemas/spi/spi-controller.yaml#
+
+properties:
+  compatible:
+    enum:
+      - qcom,ipq9574-snand
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 3
+
+  clock-names:
+    items:
+      - const: core
+      - const: aon
+      - const: iom
+
+  dmas:
+    items:
+      - description: tx DMA channel
+      - description: rx DMA channel
+      - description: cmd DMA channel
+
+  dma-names:
+    items:
+      - const: tx
+      - const: rx
+      - const: cmd
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/qcom,ipq9574-gcc.h>
+    spi@79b0000 {
+        compatible = "qcom,ipq9574-snand";
+        reg = <0x1ac00000 0x800>;
+
+        clocks = <&gcc GCC_QPIC_CLK>,
+                 <&gcc GCC_QPIC_AHB_CLK>,
+                 <&gcc GCC_QPIC_IO_MACRO_CLK>;
+        clock-names = "core", "aon", "iom";
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        flash@0 {
+            compatible = "spi-nand";
+            reg = <0>;
+            #address-cells = <1>;
+            #size-cells = <1>;
+            nand-ecc-engine = <&qpic_nand>;
+            nand-ecc-strength = <4>;
+            nand-ecc-step-size = <512>;
+        };
+    };