dt-bindings: at24: convert the binding document to yaml

Convert the binding document for at24 EEPROMs from txt to yaml. The
compatible property uses a regex pattern to address all the possible
combinations of "vendor,model" strings.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
[robh: rework compatible schema, fix missing allOf for $ref, fix errors in example]
Signed-off-by: Rob Herring <robh@kernel.org>
[Bartosz: added comments explaining the compatible property]
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Rob Herring <robh@kernel.org>

3 files changed, 187 insertions, 90 deletions

diff --git a/Documentation/devicetree/bindings/eeprom/at24.txt b/Documentation/devicetree/bindings/eeprom/at24.txt
index 22aead844d0f..c94acbb8cb0c 100644
--- a/Documentation/devicetree/bindings/eeprom/at24.txt
+++ b/Documentation/devicetree/bindings/eeprom/at24.txt
@@ -1,89 +1 @@
-EEPROMs (I2C)
-
-Required properties:
-
-  - compatible: Must be a "<manufacturer>,<model>" pair. The following <model>
-                values are supported (assuming "atmel" as manufacturer):
-
-                "atmel,24c00",
-                "atmel,24c01",
-                "atmel,24cs01",
-                "atmel,24c02",
-                "atmel,24cs02",
-                "atmel,24mac402",
-                "atmel,24mac602",
-                "atmel,spd",
-                "atmel,24c04",
-                "atmel,24cs04",
-                "atmel,24c08",
-                "atmel,24cs08",
-                "atmel,24c16",
-                "atmel,24cs16",
-                "atmel,24c32",
-                "atmel,24cs32",
-                "atmel,24c64",
-                "atmel,24cs64",
-                "atmel,24c128",
-                "atmel,24c256",
-                "atmel,24c512",
-                "atmel,24c1024",
-                "atmel,24c2048",
-
-                If <manufacturer> is not "atmel", then a fallback must be used
-                with the same <model> and "atmel" as manufacturer.
-
-                Example:
-                        compatible = "microchip,24c128", "atmel,24c128";
-
-                Supported manufacturers are:
-
-                "catalyst",
-                "microchip",
-                "nxp",
-                "ramtron",
-                "renesas",
-                "rohm",
-                "st",
-
-                Some vendors use different model names for chips which are just
-                variants of the above. Known such exceptions are listed below:
-
-                "nxp,se97b" - the fallback is "atmel,24c02",
-                "renesas,r1ex24002" - the fallback is "atmel,24c02"
-                "renesas,r1ex24016" - the fallback is "atmel,24c16"
-                "renesas,r1ex24128" - the fallback is "atmel,24c128"
-                "rohm,br24t01" - the fallback is "atmel,24c01"
-
-  - reg: The I2C address of the EEPROM.
-
-Optional properties:
-
-  - pagesize: The length of the pagesize for writing. Please consult the
-              manual of your device, that value varies a lot. A wrong value
-              may result in data loss! If not specified, a safety value of
-              '1' is used which will be very slow.
-
-  - read-only: This parameterless property disables writes to the eeprom.
-
-  - size: Total eeprom size in bytes.
-
-  - no-read-rollover: This parameterless property indicates that the
-                      multi-address eeprom does not automatically roll over
-                      reads to the next slave address. Please consult the
-                      manual of your device.
-
-  - wp-gpios: GPIO to which the write-protect pin of the chip is connected.
-
-  - address-width: number of address bits (one of 8, 16).
-
-  - num-addresses: total number of i2c slave addresses this device takes
-
-Example:
-
-eeprom@52 {
-	compatible = "atmel,24c32";
-	reg = <0x52>;
-	pagesize = <32>;
-	wp-gpios = <&gpio1 3 0>;
-	num-addresses = <8>;
-};
+This file has been moved to at24.yaml.
diff --git a/Documentation/devicetree/bindings/eeprom/at24.yaml b/Documentation/devicetree/bindings/eeprom/at24.yaml
new file mode 100644
index 000000000000..c56f27fde3b3
--- /dev/null
+++ b/Documentation/devicetree/bindings/eeprom/at24.yaml
@@ -0,0 +1,185 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Copyright 2019 BayLibre SAS
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/eeprom/at24.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: I2C EEPROMs compatible with Atmel's AT24
+
+maintainers:
+  - Bartosz Golaszewski <bgolaszewski@baylibre.com>
+
+select:
+  properties:
+    compatible:
+      contains:
+        pattern: "^atmel,(24(c|cs|mac)[0-9]+|spd)$"
+  required:
+    - compatible
+
+properties:
+  $nodename:
+    pattern: "^eeprom@[0-9a-f]{1,2}$"
+
+  # There are multiple known vendors who manufacture EEPROM chips compatible
+  # with Atmel's AT24. The compatible string requires either a single item
+  # if the memory comes from Atmel (in which case the vendor part must be
+  # 'atmel') or two items with the same 'model' part where the vendor part of
+  # the first one is the actual manufacturer and the second item is the
+  # corresponding 'atmel,<model>' from Atmel.
+  compatible:
+    oneOf:
+      - allOf:
+          - minItems: 1
+            maxItems: 2
+            items:
+              - pattern: "^(atmel|catalyst|microchip|nxp|ramtron|renesas|rohm|st),(24(c|cs|mac)[0-9]+|spd)$"
+              - pattern: "^atmel,(24(c|cs|mac)[0-9]+|spd)$"
+          - oneOf:
+              - items:
+                  pattern: c00$
+              - items:
+                  pattern: c01$
+              - items:
+                  pattern: cs01$
+              - items:
+                  pattern: c02$
+              - items:
+                  pattern: cs02$
+              - items:
+                  pattern: mac402$
+              - items:
+                  pattern: mac602$
+              - items:
+                  pattern: c04$
+              - items:
+                  pattern: cs04$
+              - items:
+                  pattern: c08$
+              - items:
+                  pattern: cs08$
+              - items:
+                  pattern: c16$
+              - items:
+                  pattern: cs16$
+              - items:
+                  pattern: c32$
+              - items:
+                  pattern: cs32$
+              - items:
+                  pattern: c64$
+              - items:
+                  pattern: cs64$
+              - items:
+                  pattern: c128$
+              - items:
+                  pattern: cs128$
+              - items:
+                  pattern: c256$
+              - items:
+                  pattern: cs256$
+              - items:
+                  pattern: c512$
+              - items:
+                  pattern: cs512$
+              - items:
+                  pattern: c1024$
+              - items:
+                  pattern: cs1024$
+              - items:
+                  pattern: c2048$
+              - items:
+                  pattern: cs2048$
+              - items:
+                  pattern: spd$
+      # These are special cases that don't conform to the above pattern.
+      # Each requires a standard at24 model as fallback.
+      - items:
+          - const: rohm,br24t01
+          - const: atmel,24c01
+      - items:
+          - const: nxp,se97b
+          - const: atmel,24c02
+      - items:
+          - const: renesas,r1ex24002
+          - const: atmel,24c02
+      - items:
+          - const: renesas,r1ex24016
+          - const: atmel,24c16
+      - items:
+          - const: renesas,r1ex24128
+          - const: atmel,24c128
+
+  reg:
+    maxItems: 1
+
+  pagesize:
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      The length of the pagesize for writing. Please consult the
+      manual of your device, that value varies a lot. A wrong value
+      may result in data loss! If not specified, a safety value of
+      '1' is used which will be very slow.
+    enum: [ 1, 8, 16, 32, 64, 128, 258 ]
+    default: 1
+
+  read-only:
+    $ref: /schemas/types.yaml#definitions/flag
+    description:
+      Disables writes to the eeprom.
+
+  size:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Total eeprom size in bytes.
+
+  no-read-rollover:
+    $ref: /schemas/types.yaml#definitions/flag
+    description:
+      Indicates that the multi-address eeprom does not automatically roll
+      over reads to the next slave address. Please consult the manual of
+      your device.
+
+  wp-gpios:
+    description:
+      GPIO to which the write-protect pin of the chip is connected.
+    maxItems: 1
+
+  address-width:
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Number of address bits.
+    default: 8
+    enum: [ 8, 16 ]
+
+  num-addresses:
+    allOf:
+      - $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Total number of i2c slave addresses this device takes.
+    default: 1
+    minimum: 1
+    maximum: 8
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      eeprom@52 {
+          compatible = "microchip,24c32", "atmel,24c32";
+          reg = <0x52>;
+          pagesize = <32>;
+          wp-gpios = <&gpio1 3 0>;
+          num-addresses = <8>;
+      };
+    };
+...
diff --git a/MAINTAINERS b/MAINTAINERS
index 296de2b51c83..320fc8bba872 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2699,7 +2699,7 @@ M:	Bartosz Golaszewski <bgolaszewski@baylibre.com>
 L:	linux-i2c@vger.kernel.org
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git
 S:	Maintained
-F:	Documentation/devicetree/bindings/eeprom/at24.txt
+F:	Documentation/devicetree/bindings/eeprom/at24.yaml
 F:	drivers/misc/eeprom/at24.c
 
 ATA OVER ETHERNET (AOE) DRIVER