[PATCH v4 0/4] Freescale Enhanced Local Bus Controller (eLBC) binding YAML conversion

[PATCH v4 0/4] Freescale Enhanced Local Bus Controller (eLBC) binding YAML conversion

[J. Neuschäfer via B4 Relay]

This series converts the fsl,elbc binding to YAML and adds new bindings
for related devices (particular kinds of chip on the eLBC).

For readability, the existing unit address syntax of <cs>,<offset>
(e.g. nand@1,0) is kept. This results in a few dtc validation warnings,
when combined with other choices in this patchset:

- For compatibility with existing kernels which don't explicitly probe
  under an eLBC controller, the "simple-bus" compatible string is kept
  on eLBC controller nodes. The validation logic requires a linear unit
  address, though (e.g. @100000000 instead of @1,0)

The patches in this series were previously part of the following series,
which turned out to be too large and unwieldy:
[PATCH v2 00/12] YAML conversion of several Freescale/PowerPC DT bindings
https://lore.kernel.org/lkml/20250207-ppcyaml-v2-0-8137b0c42526@posteo.net/

Changelogs are present in the individual patches.

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
---
Changes in v4:
- Reintroduce patch "dt-bindings: mtd: raw-nand-chip: Relax node name pattern"
- Link to v3: https://lore.kernel.org/r/20250226-ppcyaml-elbc-v3-0-a90ed71da838@posteo.net

---
J. Neuschäfer (4):
      dt-bindings: mtd: raw-nand-chip: Relax node name pattern
      dt-bindings: memory-controllers: Add fsl,elbc-gpcm-uio
      dt-bindings: nand: Add fsl,elbc-fcm-nand
      dt-bindings: memory-controllers: Convert fsl,elbc to YAML

 .../memory-controllers/fsl,elbc-gpcm-uio.yaml      |  59 ++++++++
 .../bindings/memory-controllers/fsl,elbc.yaml      | 158 +++++++++++++++++++++
 .../devicetree/bindings/mtd/fsl,elbc-fcm-nand.yaml |  68 +++++++++
 .../devicetree/bindings/mtd/raw-nand-chip.yaml     |   2 +-
 .../devicetree/bindings/powerpc/fsl/lbc.txt        |  43 ------
 5 files changed, 286 insertions(+), 44 deletions(-)
---
base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
change-id: 20250220-ppcyaml-elbc-bb85941fb250

Best regards,
-- 
J. Neuschäfer <j.ne@posteo.net>

[PATCH v4 1/4] dt-bindings: mtd: raw-nand-chip: Relax node name pattern

[J. Neuschäfer via B4 Relay]

From: "J. Neuschäfer" <j.ne@posteo.net>

In some scenarios, such as under the Freescale eLBC bus, there are raw
NAND chips with a unit address that has a comma in it (cs,offset).
For reasons of compatibility with historical device trees and
readability of the unit addresses, this format is kept.

Relax the $nodename pattern in raw-nand-chip.yaml to allow such unit
addresses. Unfortunately $nonenames defined in bindings that reference
raw-nand

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
---

V4:
- reintroduce patch to silence dtc validation error, after discussion
  with Rob Herring and Miquèl Raynal
- add some more detail to the commit message
- remove unit address format rather than extending it
  (old pattern: "^nand@[a-f0-9](,[0-9a-f]*)?$")

V3:
- remove patch after discussion with Miquèl Raynal

V2:
- new patch
---
 Documentation/devicetree/bindings/mtd/raw-nand-chip.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mtd/raw-nand-chip.yaml b/Documentation/devicetree/bindings/mtd/raw-nand-chip.yaml
index 092448d7bfc5ccd246ca4b2341464e18722a2d51..d655f6673fc31b1d9ee7cd734cbe1d310f88090b 100644
--- a/Documentation/devicetree/bindings/mtd/raw-nand-chip.yaml
+++ b/Documentation/devicetree/bindings/mtd/raw-nand-chip.yaml
@@ -25,7 +25,7 @@ description: |
 
 properties:
   $nodename:
-    pattern: "^nand@[a-f0-9]$"
+    pattern: "^nand@"
 
   reg:
     description:

-- 
2.48.0.rc1.219.gb6b6757d772

Re: [PATCH v4 1/4] dt-bindings: mtd: raw-nand-chip: Relax node name pattern

[Rob Herring (Arm)]

On Thu, 13 Mar 2025 22:35:44 +0100, J. Neuschäfer wrote:
> In some scenarios, such as under the Freescale eLBC bus, there are raw
> NAND chips with a unit address that has a comma in it (cs,offset).
> For reasons of compatibility with historical device trees and
> readability of the unit addresses, this format is kept.
> 
> Relax the $nodename pattern in raw-nand-chip.yaml to allow such unit
> addresses. Unfortunately $nonenames defined in bindings that reference
> raw-nand
> 
> Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
> ---
> 
> V4:
> - reintroduce patch to silence dtc validation error, after discussion
>   with Rob Herring and Miquèl Raynal
> - add some more detail to the commit message
> - remove unit address format rather than extending it
>   (old pattern: "^nand@[a-f0-9](,[0-9a-f]*)?$")
> 
> V3:
> - remove patch after discussion with Miquèl Raynal
> 
> V2:
> - new patch
> ---
>  Documentation/devicetree/bindings/mtd/raw-nand-chip.yaml | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>

[PATCH v4 2/4] dt-bindings: memory-controllers: Add fsl,elbc-gpcm-uio

[J. Neuschäfer via B4 Relay]

From: "J. Neuschäfer" <j.ne@posteo.net>

Formalize the binding already supported by the uio_fsl_elbc_gpcm.c
driver.

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
---

V4:
- no changes

V3:
- add review tags

V2:
- split out from fsl,elbc patch
- add description
- remove "device_type" property
- move to bindings/memory-controllers
---
 .../memory-controllers/fsl,elbc-gpcm-uio.yaml      | 59 ++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/Documentation/devicetree/bindings/memory-controllers/fsl,elbc-gpcm-uio.yaml b/Documentation/devicetree/bindings/memory-controllers/fsl,elbc-gpcm-uio.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..381584b400a0ad98c6d9e0b38f2877d44603ed84
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/fsl,elbc-gpcm-uio.yaml
@@ -0,0 +1,59 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/fsl,elbc-gpcm-uio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Userspace I/O interface for Freescale eLBC devices
+
+description:
+  The Freescale Enhanced Local Bus controller (eLBC) supports flexible access
+  to memory devices, through the General-Purpose Chip-select Machine (GPCM).
+  The purpose of this binding is to designate devices attached to eLBC/GPMC for
+  use by userspace.
+
+maintainers:
+  - J. Neuschäfer <j.ne@posteo.net>
+
+properties:
+  compatible:
+    const: fsl,elbc-gpcm-uio
+
+  reg:
+    maxItems: 1
+
+  elbc-gpcm-br:
+    description: Base Register (BR) value to set
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  elbc-gpcm-or:
+    description: Option Register (OR) value to set
+    $ref: /schemas/types.yaml#/definitions/uint32
+
+  interrupts:
+    maxItems: 1
+
+  uio_name:
+    $ref: /schemas/types.yaml#/definitions/string
+
+required:
+  - compatible
+  - reg
+  - elbc-gpcm-br
+  - elbc-gpcm-or
+
+additionalProperties: false
+
+examples:
+  - |
+    localbus {
+        #address-cells = <2>;
+        #size-cells = <1>;
+
+        simple-periph@2,0 {
+            compatible = "fsl,elbc-gpcm-uio";
+            reg = <0x2 0x0 0x10000>;
+            elbc-gpcm-br = <0xfd810800>;
+            elbc-gpcm-or = <0xffff09f7>;
+        };
+    };

-- 
2.48.0.rc1.219.gb6b6757d772

[PATCH v4 3/4] dt-bindings: nand: Add fsl,elbc-fcm-nand

[J. Neuschäfer via B4 Relay]

From: "J. Neuschäfer" <j.ne@posteo.net>

Formalize the binding already supported by the fsl_elbc_nand.c driver
and used in several device trees in arch/powerpc/boot/dts/.

raw-nand-chip.yaml is referenced in order to accommodate situations in
which the ECC parameters settings are set in the device tree. One such
example is in arch/powerpc/boot/dts/turris1x.dts:

	/* MT29F2G08ABAEAWP:E NAND */
	nand@1,0 {
		compatible = "fsl,p2020-fcm-nand", "fsl,elbc-fcm-nand";
		reg = <0x1 0x0 0x00040000>;
		nand-ecc-mode = "soft";
		nand-ecc-algo = "bch";

		partitions { ... };
	};

Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
---

V4:
- no changes

V3:
- remove unnecessary #address/size-cells from nand node in example
- add Frank Li's review tag
- add missing end of document marker (...)
- explain choice to reference raw-nand-chip.yaml

V2:
- split out from fsl,elbc binding patch
- constrain #address-cells and #size-cells
- add a general description
- use unevaluatedProperties=false instead of additionalProperties=false
- fix property order to comply with dts coding style
- include raw-nand-chip.yaml instead of nand-chip.yaml
---
 .../devicetree/bindings/mtd/fsl,elbc-fcm-nand.yaml | 68 ++++++++++++++++++++++
 1 file changed, 68 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/fsl,elbc-fcm-nand.yaml b/Documentation/devicetree/bindings/mtd/fsl,elbc-fcm-nand.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..91e8f2f9ff26da0f5a3f9bf276955ed32e9e7bc6
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/fsl,elbc-fcm-nand.yaml
@@ -0,0 +1,68 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mtd/fsl,elbc-fcm-nand.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NAND flash attached to Freescale eLBC
+
+description:
+  The Freescale Enhanced Local Bus controller (eLBC) contains logic to
+  interface with NAND flash, called the NAND Flash Control Machine (FCM).
+  This binding describes flash attached to an eLBC using the FCM.
+
+maintainers:
+  - J. Neuschäfer <j.ne@posteo.net>
+
+allOf:
+  - $ref: raw-nand-chip.yaml#
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - fsl,mpc8313-fcm-nand
+              - fsl,mpc8315-fcm-nand
+              - fsl,mpc8377-fcm-nand
+              - fsl,mpc8378-fcm-nand
+              - fsl,mpc8379-fcm-nand
+              - fsl,mpc8536-fcm-nand
+              - fsl,mpc8569-fcm-nand
+              - fsl,mpc8572-fcm-nand
+              - fsl,p1020-fcm-nand
+              - fsl,p1021-fcm-nand
+              - fsl,p1025-fcm-nand
+              - fsl,p2020-fcm-nand
+          - const: fsl,elbc-fcm-nand
+      - const: fsl,elbc-fcm-nand
+
+  reg:
+    maxItems: 1
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    localbus {
+        #address-cells = <2>;
+        #size-cells = <1>;
+
+        nand@1,0 {
+            compatible = "fsl,mpc8315-fcm-nand",
+                         "fsl,elbc-fcm-nand";
+            reg = <0x1 0x0 0x2000>;
+        };
+    };
+
+...

-- 
2.48.0.rc1.219.gb6b6757d772

Re: [PATCH v4 3/4] dt-bindings: nand: Add fsl,elbc-fcm-nand

[Rob Herring (Arm)]

On Thu, 13 Mar 2025 22:35:46 +0100, J. Neuschäfer wrote:
> Formalize the binding already supported by the fsl_elbc_nand.c driver
> and used in several device trees in arch/powerpc/boot/dts/.
> 
> raw-nand-chip.yaml is referenced in order to accommodate situations in
> which the ECC parameters settings are set in the device tree. One such
> example is in arch/powerpc/boot/dts/turris1x.dts:
> 
> 	/* MT29F2G08ABAEAWP:E NAND */
> 	nand@1,0 {
> 		compatible = "fsl,p2020-fcm-nand", "fsl,elbc-fcm-nand";
> 		reg = <0x1 0x0 0x00040000>;
> 		nand-ecc-mode = "soft";
> 		nand-ecc-algo = "bch";
> 
> 		partitions { ... };
> 	};
> 
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
> ---
> 
> V4:
> - no changes
> 
> V3:
> - remove unnecessary #address/size-cells from nand node in example
> - add Frank Li's review tag
> - add missing end of document marker (...)
> - explain choice to reference raw-nand-chip.yaml
> 
> V2:
> - split out from fsl,elbc binding patch
> - constrain #address-cells and #size-cells
> - add a general description
> - use unevaluatedProperties=false instead of additionalProperties=false
> - fix property order to comply with dts coding style
> - include raw-nand-chip.yaml instead of nand-chip.yaml
> ---
>  .../devicetree/bindings/mtd/fsl,elbc-fcm-nand.yaml | 68 ++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
> 

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>

[PATCH v4 4/4] dt-bindings: memory-controllers: Convert fsl,elbc to YAML

[J. Neuschäfer via B4 Relay]

From: "J. Neuschäfer" <j.ne@posteo.net>

Convert the Freescale localbus controller bindings from text form to
YAML. Compared to the .txt version, the YAML binding contains a new
usage example with FCM NAND flash, and a full list of compatible strings
based on current usage in arch/powerpc/boot/dts/.

Note that the both the compatible strings and the unit address format
are kept as-is, for compatibility with existing kernels and device
trees, as well as unit address readability. This results in dts
validation warnings:

  Warning (simple_bus_reg): /example-0/localbus@f0010100/board-control@1,0:
  simple-bus unit address format error, expected "100000000"

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
---

V4:
- no changes

V3:
- move this patch after the GPCM/FCM patches to dtschema/dtc warnings
  due to missing bindings for fsl,elbc-gpcm-uio and fsl,elbc-fcm-nand
- add "simple-bus" again, for compatibility with existing DTs/drivers
  based on discussion with Crystal Wood and Rob Herring
- fix fsl,pq2-localbus compatible properties based on mgcoge.dts / ep8248e.dts
  (was missing "simple-bus")
- add board-control (bcsr) example again, now using the compatible
  string listed in Documentation/devicetree/bindings/board/fsl,bcsr.yaml
- remove interrupt-parent property from example
- rework the commit message

V2:
- fix order of properties in examples, according to dts coding style
- move to Documentation/devicetree/bindings/memory-controllers
- clarify the commit message a tiny bit
- remove unnecessary multiline markers (|)
- define address format in patternProperties
- trim subject line (remove "binding")
- remove use of "simple-bus", because it's technically incorrect
---
 .../bindings/memory-controllers/fsl,elbc.yaml      | 158 +++++++++++++++++++++
 .../devicetree/bindings/powerpc/fsl/lbc.txt        |  43 ------
 2 files changed, 158 insertions(+), 43 deletions(-)

diff --git a/Documentation/devicetree/bindings/memory-controllers/fsl,elbc.yaml b/Documentation/devicetree/bindings/memory-controllers/fsl,elbc.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..620d7e7c62df35c754a01498391d35ede03cdf87
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/fsl,elbc.yaml
@@ -0,0 +1,158 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/memory-controllers/fsl,elbc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale Enhanced Local Bus Controller
+
+maintainers:
+  - J. Neuschäfer <j.ne@posteo.net>
+
+properties:
+  $nodename:
+    pattern: "^localbus@[0-9a-f]+$"
+
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - fsl,mpc8313-elbc
+              - fsl,mpc8315-elbc
+              - fsl,mpc8377-elbc
+              - fsl,mpc8378-elbc
+              - fsl,mpc8379-elbc
+              - fsl,mpc8536-elbc
+              - fsl,mpc8569-elbc
+              - fsl,mpc8572-elbc
+              - fsl,p1020-elbc
+              - fsl,p1021-elbc
+              - fsl,p1023-elbc
+              - fsl,p2020-elbc
+              - fsl,p2041-elbc
+              - fsl,p3041-elbc
+              - fsl,p4080-elbc
+              - fsl,p5020-elbc
+              - fsl,p5040-elbc
+          - const: fsl,elbc
+          - const: simple-bus
+
+      - items:
+          - enum:
+              - fsl,mpc8247-localbus
+              - fsl,mpc8248-localbus
+              - fsl,mpc8272-localbus
+          - const: fsl,pq2-localbus
+          - const: simple-bus
+
+      - items:
+          - enum:
+              - fsl,mpc8247-localbus
+              - fsl,mpc8248-localbus
+              - fsl,mpc8360-localbus
+          - const: fsl,pq2pro-localbus
+          - const: simple-bus
+
+      - items:
+          - enum:
+              - fsl,mpc8540-localbus
+              - fsl,mpc8544-lbc
+              - fsl,mpc8544-localbus
+              - fsl,mpc8548-lbc
+              - fsl,mpc8548-localbus
+              - fsl,mpc8560-localbus
+              - fsl,mpc8568-localbus
+          - const: fsl,pq3-localbus
+          - const: simple-bus
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  "#address-cells":
+    enum: [2, 3]
+    description:
+      The first cell is the chipselect number, and the remaining cells are the
+      offset into the chipselect.
+
+  "#size-cells":
+    enum: [1, 2]
+    description:
+      Either one or two, depending on how large each chipselect can be.
+
+  ranges:
+    description:
+      Each range corresponds to a single chipselect, and covers the entire
+      access window as configured.
+
+patternProperties:
+  # format: name@chipselect,address
+  "^.*@[0-9a-f]+,[0-9a-f]+$":
+    type: object
+
+additionalProperties: false
+
+examples:
+  - |
+    localbus@f0010100 {
+        compatible = "fsl,mpc8272-localbus",
+                     "fsl,pq2-localbus",
+                     "simple-bus";
+        reg = <0xf0010100 0x40>;
+        ranges = <0x0 0x0 0xfe000000 0x02000000
+                  0x1 0x0 0xf4500000 0x00008000
+                  0x2 0x0 0xfd810000 0x00010000>;
+        #address-cells = <2>;
+        #size-cells = <1>;
+
+        flash@0,0 {
+            compatible = "jedec-flash";
+            reg = <0x0 0x0 0x2000000>;
+            bank-width = <4>;
+            device-width = <1>;
+        };
+
+        board-control@1,0 {
+            reg = <0x1 0x0 0x20>;
+            compatible = "fsl,mpc8360mds-bcsr";
+        };
+
+        simple-periph@2,0 {
+            compatible = "fsl,elbc-gpcm-uio";
+            reg = <0x2 0x0 0x10000>;
+            elbc-gpcm-br = <0xfd810800>;
+            elbc-gpcm-or = <0xffff09f7>;
+        };
+    };
+
+  - |
+    localbus@e0005000 {
+        compatible = "fsl,mpc8315-elbc", "fsl,elbc", "simple-bus";
+        reg = <0xe0005000 0x1000>;
+        ranges = <0x0 0x0 0xfe000000 0x00800000
+                  0x1 0x0 0xe0600000 0x00002000
+                  0x2 0x0 0xf0000000 0x00020000
+                  0x3 0x0 0xfa000000 0x00008000>;
+        #address-cells = <2>;
+        #size-cells = <1>;
+        interrupts = <77 0x8>;
+
+        flash@0,0 {
+            compatible = "cfi-flash";
+            reg = <0x0 0x0 0x800000>;
+            #address-cells = <1>;
+            #size-cells = <1>;
+            bank-width = <2>;
+            device-width = <1>;
+        };
+
+        nand@1,0 {
+            compatible = "fsl,mpc8315-fcm-nand",
+                         "fsl,elbc-fcm-nand";
+            reg = <0x1 0x0 0x2000>;
+            #address-cells = <1>;
+            #size-cells = <1>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/powerpc/fsl/lbc.txt b/Documentation/devicetree/bindings/powerpc/fsl/lbc.txt
deleted file mode 100644
index 1c80fcedebb52049721fbd61c4dd4c57133bd47c..0000000000000000000000000000000000000000
--- a/Documentation/devicetree/bindings/powerpc/fsl/lbc.txt
+++ /dev/null
@@ -1,43 +0,0 @@
-* Chipselect/Local Bus
-
-Properties:
-- name : Should be localbus
-- #address-cells : Should be either two or three.  The first cell is the
-                   chipselect number, and the remaining cells are the
-                   offset into the chipselect.
-- #size-cells : Either one or two, depending on how large each chipselect
-                can be.
-- ranges : Each range corresponds to a single chipselect, and cover
-           the entire access window as configured.
-
-Example:
-	localbus@f0010100 {
-		compatible = "fsl,mpc8272-localbus",
-			   "fsl,pq2-localbus";
-		#address-cells = <2>;
-		#size-cells = <1>;
-		reg = <0xf0010100 0x40>;
-
-		ranges = <0x0 0x0 0xfe000000 0x02000000
-			  0x1 0x0 0xf4500000 0x00008000
-			  0x2 0x0 0xfd810000 0x00010000>;
-
-		flash@0,0 {
-			compatible = "jedec-flash";
-			reg = <0x0 0x0 0x2000000>;
-			bank-width = <4>;
-			device-width = <1>;
-		};
-
-		board-control@1,0 {
-			reg = <0x1 0x0 0x20>;
-			compatible = "fsl,mpc8272ads-bcsr";
-		};
-
-		simple-periph@2,0 {
-			compatible = "fsl,elbc-gpcm-uio";
-			reg = <0x2 0x0 0x10000>;
-			elbc-gpcm-br = <0xfd810800>;
-			elbc-gpcm-or = <0xffff09f7>;
-		};
-	};

-- 
2.48.0.rc1.219.gb6b6757d772

Re: [PATCH v4 4/4] dt-bindings: memory-controllers: Convert fsl,elbc to YAML

[Rob Herring (Arm)]

On Thu, 13 Mar 2025 22:35:47 +0100, J. Neuschäfer wrote:
> Convert the Freescale localbus controller bindings from text form to
> YAML. Compared to the .txt version, the YAML binding contains a new
> usage example with FCM NAND flash, and a full list of compatible strings
> based on current usage in arch/powerpc/boot/dts/.
> 
> Note that the both the compatible strings and the unit address format
> are kept as-is, for compatibility with existing kernels and device
> trees, as well as unit address readability. This results in dts
> validation warnings:
> 
>   Warning (simple_bus_reg): /example-0/localbus@f0010100/board-control@1,0:
>   simple-bus unit address format error, expected "100000000"
> 
> Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
> ---
> 
> V4:
> - no changes
> 
> V3:
> - move this patch after the GPCM/FCM patches to dtschema/dtc warnings
>   due to missing bindings for fsl,elbc-gpcm-uio and fsl,elbc-fcm-nand
> - add "simple-bus" again, for compatibility with existing DTs/drivers
>   based on discussion with Crystal Wood and Rob Herring
> - fix fsl,pq2-localbus compatible properties based on mgcoge.dts / ep8248e.dts
>   (was missing "simple-bus")
> - add board-control (bcsr) example again, now using the compatible
>   string listed in Documentation/devicetree/bindings/board/fsl,bcsr.yaml
> - remove interrupt-parent property from example
> - rework the commit message
> 
> V2:
> - fix order of properties in examples, according to dts coding style
> - move to Documentation/devicetree/bindings/memory-controllers
> - clarify the commit message a tiny bit
> - remove unnecessary multiline markers (|)
> - define address format in patternProperties
> - trim subject line (remove "binding")
> - remove use of "simple-bus", because it's technically incorrect
> ---
>  .../bindings/memory-controllers/fsl,elbc.yaml      | 158 +++++++++++++++++++++
>  .../devicetree/bindings/powerpc/fsl/lbc.txt        |  43 ------
>  2 files changed, 158 insertions(+), 43 deletions(-)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
Documentation/devicetree/bindings/memory-controllers/fsl,elbc.example.dts:29.23-34.15: Warning (simple_bus_reg): /example-0/localbus@f0010100/flash@0,0: simple-bus unit address format error, expected "0"
Documentation/devicetree/bindings/memory-controllers/fsl,elbc.example.dts:36.31-39.15: Warning (simple_bus_reg): /example-0/localbus@f0010100/board-control@1,0: simple-bus unit address format error, expected "100000000"
Documentation/devicetree/bindings/memory-controllers/fsl,elbc.example.dts:41.31-46.15: Warning (simple_bus_reg): /example-0/localbus@f0010100/simple-periph@2,0: simple-bus unit address format error, expected "200000000"
Documentation/devicetree/bindings/memory-controllers/fsl,elbc.example.dts:82.23-89.15: Warning (simple_bus_reg): /example-1/localbus@e0005000/flash@0,0: simple-bus unit address format error, expected "0"
Documentation/devicetree/bindings/memory-controllers/fsl,elbc.example.dts:91.22-97.15: Warning (simple_bus_reg): /example-1/localbus@e0005000/nand@1,0: simple-bus unit address format error, expected "100000000"

doc reference errors (make refcheckdocs):
Warning: Documentation/devicetree/bindings/display/ssd1289fb.txt references a file that doesn't exist: Documentation/devicetree/bindings/powerpc/fsl/lbc.txt
Documentation/devicetree/bindings/display/ssd1289fb.txt: Documentation/devicetree/bindings/powerpc/fsl/lbc.txt

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250313-ppcyaml-elbc-v4-4-55903722d9ea@posteo.net

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.