Re: [PATCH RFC 9/9] dt-bindings: nand: Convert fsl,elbc bindings to YAML

Krzysztof Kozlowski
2025-01-27T08:37:46Z

On Sun, Jan 26, 2025 at 07:59:04PM +0100, J. Neuschäfer wrote:
> Convert the Freescale localbus controller bindings from text form to
> YAML. The list of compatible strings reflects current usage.

simple-bus and 20 other compatibles you used were not present in the
original binding. Does above "list of compatible strings" mean you just
added them?

>
> Changes compared to the txt version:
> - removed the board-control (fsl,mpc8272ads-bcsr) node because it only
> appears in this example and nowhere else
> - added a new example with NAND flash
>
> Remaining issues:
> - The localbus is not really a simple-bus: Unit addresses are not simply
> addresses on a memory bus. Instead, they have a format: The first cell
> is a chip select number, the remaining one or two cells are bus
> addresses.
>
> Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
> ---
> .../devicetree/bindings/mtd/fsl,elbc-fcm-nand.yaml | 61 +++++++++
> .../bindings/powerpc/fsl/fsl,elbc-gpcm-uio.yaml | 55 ++++++++

Please split the conversion from adding new bindings. For example above
file and its compatible fsl,elbc-gpcm-uio was not documented in original
TXT.

...

> diff --git a/Documentation/devicetree/bindings/powerpc/fsl/fsl,elbc.yaml b/Documentation/devicetree/bindings/powerpc/fsl/fsl,elbc.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..6bbceb82c77826499abe85879e9189b18d396eea
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/powerpc/fsl/fsl,elbc.yaml
> @@ -0,0 +1,150 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/powerpc/fsl/fsl,elbc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Freescale Enhanced Local Bus Controller

What sort of bus is it? Memory bus? Then place it with others, see
memory directory.

> +
> +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:
> + - const: fsl,mpc8272-localbus
> + - const: fsl,pq2-localbus
> +
> + - 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:
> + "^.*@.*$":
> + type: object

And probably you need
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + localbus@f0010100 {
> + compatible = "fsl,mpc8272-localbus",
> + "fsl,pq2-localbus";
> + #address-cells = <2>;
> + #size-cells = <1>;
> + reg = <0xf0010100 0x40>;

compatible, then reg - see DTS coding style.

> +
> + ranges = <0x0 0x0 0xfe000000 0x02000000
> + 0x1 0x0 0xf4500000 0x00008000
> + 0x2 0x0 0xfd810000 0x00010000>;
> +
> + flash@0,0 {
> + compatible = "jedec-flash";
> + reg = <0x0 0x0 0x2000000>;

Well, here it is correct

> + bank-width = <4>;
> + device-width = <1>;
> + };
> +
> + simple-periph@2,0 {
> + compatible = "fsl,elbc-gpcm-uio";
> + reg = <0x2 0x0 0x10000>;
> + elbc-gpcm-br = <0xfd810800>;
> + elbc-gpcm-or = <0xffff09f7>;
> + };
> + };
> +
> + - |
> + localbus@e0005000 {

compatible, reg

> + #address-cells = <2>;
> + #size-cells = <1>;
> + compatible = "fsl,mpc8315-elbc", "fsl,elbc", "simple-bus";
> + reg = <0xe0005000 0x1000>;
> + interrupts = <77 0x8>;
> + interrupt-parent = <&ipic>;
> +
> + ranges = <0x0 0x0 0xfe000000 0x00800000
> + 0x1 0x0 0xe0600000 0x00002000
> + 0x2 0x0 0xf0000000 0x00020000
> + 0x3 0x0 0xfa000000 0x00008000>;
> +
> + flash@0,0 {

compatible, reg

> + #address-cells = <1>;
> + #size-cells = <1>;
> + compatible = "cfi-flash";
> + reg = <0x0 0x0 0x800000>;
> + bank-width = <2>;
> + device-width = <1>;
> + };
> +
> + nand@1,0 {

compatible, reg

> + #address-cells = <1>;
> + #size-cells = <1>;
> + compatible = "fsl,mpc8315-fcm-nand",
> + "fsl,elbc-fcm-nand";
> + reg = <0x1 0x0 0x2000>;
> + };

Best regards,
Krzysztof