[PATCH 1/4] dt-bindings: mtd: Add YAML schemas for the generic NAND options

Maxime Ripard maxime.ripard at bootlin.com
Mon Apr 1 14:13:53 PDT 2019


The NAND chips in MTD have a bunch of generic options that are needed in a
device tree. Add a YAML schemas for those.

Signed-off-by: Maxime Ripard <maxime.ripard at bootlin.com>
---
 Documentation/devicetree/bindings/mtd/nand-controller.yaml | 131 +++++++-
 1 file changed, 131 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/nand-controller.yaml

diff --git a/Documentation/devicetree/bindings/mtd/nand-controller.yaml b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
new file mode 100644
index 000000000000..05b1afb34972
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/nand-controller.yaml
@@ -0,0 +1,131 @@
+# SPDX-License-Identifier: (GPL-2.0+ OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/nand-controller.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NAND Chip and NAND Controller Generic Binding
+
+maintainers:
+  - Boris Brezillon <bbrezillon at kernel.org>
+  - Miquel Raynal <miquel.raynal at bootlin.com>
+  - Richard Weinberger <richard at nod.at>
+
+description: |
+  The NAND controller should be represented with its own DT node, and
+  all NAND chips attached to this controller should be defined as
+  children nodes of the NAND controller. This representation should be
+  enforced even for simple controllers supporting only one chip.
+
+  The ECC strength and ECC step size properties define the correction
+  capability of a controller. Together, they say a controller can
+  correct {strength} bit errors per {size} bytes.
+
+  The interpretation of these parameters is implementation-defined, so
+  not all implementations must support all possible
+  combinations. However, implementations are encouraged to further
+  specify the value(s) they support.
+
+properties:
+  $nodename:
+    pattern: "^nand-controller(@.*)?"
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  ranges: true
+
+patternProperties:
+  "^nand@[a-z0-9]$":
+    properties:
+      reg:
+        description:
+          Contains the native Ready/Busy IDs.
+
+      nand-ecc-mode:
+        allOf:
+          - $ref: /schemas/types.yaml#/definitions/string
+          - enum: [ none, soft, hw, hw_syndrome, hw_oob_first, on-die ]
+        description:
+          Operation mode of the NAND ecc mode. soft_bch is deprecated
+          and should be replaced by soft and nand-ecc-algo
+
+      nand-ecc-algo:
+        allOf:
+          - $ref: /schemas/types.yaml#/definitions/string
+          - enum: [ hamming, bch, rs ]
+        description:
+          Algorithm of NAND ECC.
+
+      nand-bus-width:
+        allOf:
+          - $ref: /schemas/types.yaml#/definitions/uint32
+          - enum: [ 8, 16 ]
+          - default: 8
+        description:
+          Bus width to the NAND chip
+
+      nand-on-flash-bbt:
+        $ref: /schemas/types.yaml#/definitions/flag
+        description:
+          Enable the on-flash Bad Block Table
+
+      nand-ecc-strength:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description:
+          Number of bits to correct per ECC step.
+
+      nand-ecc-step-size:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description:
+          Number of data bytes covered by a single ECC step.
+
+      nand-ecc-maximize:
+        $ref: /schemas/types.yaml#/definitions/flag
+        description:
+          Whether or not the ECC strength should be maximized. The
+          maximum ECC strength is both controller and chip
+          dependent. The controller side has to select the ECC config
+          providing the best strength and taking the OOB area size
+          constraint into account.  This is particularly useful when
+          only the in-band area is used by the upper layers, and you
+          want to make your NAND as reliable as possible.
+
+      nand-is-boot-medium:
+        $ref: /schemas/types.yaml#/definitions/flag
+        description:
+          Whether or not the NAND chip is a boot medium. Drivers might
+          use this information to select ECC algorithms supported by
+          the boot ROM or similar restrictions.
+
+      nand-rb:
+        $ref: /schemas/types.yaml#/definitions/uint32-array
+        description:
+          Contains the native Ready/Busy IDs.
+
+    required:
+      - reg
+
+required:
+  - "#address-cells"
+  - "#size-cells"
+
+examples:
+  - |
+    nand-controller {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      /* controller specific properties */
+
+      nand at 0 {
+        reg = <0>;
+        nand-ecc-mode = "soft";
+        nand-ecc-algo = "bch";
+
+        /* controller specific properties */
+      };
+    };

base-commit: aa63f222af3e5991099ebcecca7c474d8285c7c4
-- 
git-series 0.9.1



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