[PATCH v3 1/4] dt-bindings: mtd: microchip-nand: convert txt to yaml
Rob Herring
robh at kernel.org
Mon Jun 2 05:42:33 PDT 2025
On Mon, Jun 02, 2025 at 06:58:52AM +0000, Balamanikandan.Gunasundar at microchip.com wrote:
> Hi,
>
> On 02/06/25 11:05 am, Balamanikandan Gunasundar wrote:
> > Convert text to yaml for microchip nand controller
> >
> > Signed-off-by: Balamanikandan Gunasundar <balamanikandan.gunasundar at microchip.com>
> > ---
> > .../devicetree/bindings/mtd/atmel-nand.txt | 50 ------
> > .../mtd/microchip,nand-controller.yaml | 169 ++++++++++++++++++
> > 2 files changed, 169 insertions(+), 50 deletions(-)
> > create mode 100644 Documentation/devicetree/bindings/mtd/microchip,nand-controller.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> > index e36c35b17873..dbbc17a866f2 100644
> > --- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> > +++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
> > @@ -1,53 +1,3 @@
> > -Atmel NAND flash controller bindings
> > -
> > -The NAND flash controller node should be defined under the EBI bus (see
> > -Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt).
> > -One or several NAND devices can be defined under this NAND controller.
> > -The NAND controller might be connected to an ECC engine.
> > -
> > -* NAND controller bindings:
> > -
> > -Required properties:
> > -- compatible: should be one of the following
> > - "atmel,at91rm9200-nand-controller"
> > - "atmel,at91sam9260-nand-controller"
> > - "atmel,at91sam9261-nand-controller"
> > - "atmel,at91sam9g45-nand-controller"
> > - "atmel,sama5d3-nand-controller"
> > - "microchip,sam9x60-nand-controller"
> > -- ranges: empty ranges property to forward EBI ranges definitions.
> > -- #address-cells: should be set to 2.
> > -- #size-cells: should be set to 1.
> > -- atmel,nfc-io: phandle to the NFC IO block. Only required for sama5d3
> > - controllers.
> > -- atmel,nfc-sram: phandle to the NFC SRAM block. Only required for sama5d3
> > - controllers.
> > -
> > -Optional properties:
> > -- ecc-engine: phandle to the PMECC block. Only meaningful if the SoC embeds
> > - a PMECC engine.
> > -
> > -* NAND device/chip bindings:
> > -
> > -Required properties:
> > -- reg: describes the CS lines assigned to the NAND device. If the NAND device
> > - exposes multiple CS lines (multi-dies chips), your reg property will
> > - contain X tuples of 3 entries.
> > - 1st entry: the CS line this NAND chip is connected to
> > - 2nd entry: the base offset of the memory region assigned to this
> > - device (always 0)
> > - 3rd entry: the memory region size (always 0x800000)
> > -
> > -Optional properties:
> > -- rb-gpios: the GPIO(s) used to check the Ready/Busy status of the NAND.
> > -- cs-gpios: the GPIO(s) used to control the CS line.
> > -- det-gpios: the GPIO used to detect if a Smartmedia Card is present.
> > -- atmel,rb: an integer identifying the native Ready/Busy pin. Only meaningful
> > - on sama5 SoCs.
> > -
> > -All generic properties are described in the generic yaml files under
> > -Documentation/devicetree/bindings/mtd/.
> > -
> > * ECC engine (PMECC) bindings:
> >
> > Required properties:
> > diff --git a/Documentation/devicetree/bindings/mtd/microchip,nand-controller.yaml b/Documentation/devicetree/bindings/mtd/microchip,nand-controller.yaml
> > new file mode 100644
> > index 000000000000..2b0d03343611
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mtd/microchip,nand-controller.yaml
> > @@ -0,0 +1,169 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/mtd/microchip,nand-controller.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Microchip NAND flash controller
> > +
> > +maintainers:
> > + - Balamanikandan Gunasundar <balamanikandan.gunasundar at microchip.com>
> > +
> > +description: |
Don't need '|'
> > + The NAND flash controller node should be defined under the EBI bus (see
> > + Documentation/devicetree/bindings/memory-controllers/atmel,ebi.txt).
Please don't keep references to old bindings. Really, you should convert
this binding first.
> > + One or several NAND devices can be defined under this NAND controller.
> > + The NAND controller might be connected to an ECC engine.
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - atmel,at91rm9200-nand-controller
> > + - atmel,at91sam9260-nand-controller
> > + - atmel,at91sam9261-nand-controller
> > + - atmel,at91sam9g45-nand-controller
> > + - atmel,sama5d3-nand-controller
> > + - microchip,sam9x60-nand-controller
> > +
> > + ranges:
> > + description: empty ranges property to forward EBI ranges definitions.
> > +
> > + ecc-engine:
> > + description:
> > + phandle to the PMECC block. Only meaningful if the SoC embeds a PMECC
> > + engine. Refer microchip,pmecc.yaml
> > +
> > + "#address-cells":
> > + const: 2
> > +
> > + "#size-cells":
> > + const: 1
> nand-controller.yaml has this values defined as
>
> "#address-cells":
> const: 1
>
> "#size-cells":
> const: 0
>
> I am unable to overwrite this as they are const values. Microchip's
> nand_controller is a child node of ebi unlike other nand controllers
> where i need to overwrite this. I didn't inherit nand-controller.yaml to
> has this defined locally.
It is matching on the node name. More below...
>
> I upgraded dtschema and ran dt_binding_check and dtb_check again for all
> the bindings in this series as recommended in v2 comments. But I don't
> get the error below
>
> https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250311122847.90081-2-balamanikandan.gunasundar@microchip.com/
>
> I am not sure what else I am missing. Your comments please?
>
> Bala.
>
>
> > +
> > + atmel,nfc-io:
> > + $ref: /schemas/types.yaml#/definitions/phandle
> > + description: phandle to the NFC IO block. Only applicable for atmel,sama5d3-nand-controller
> > +
> > + atmel,nfc-sram:
> > + $ref: /schemas/types.yaml#/definitions/phandle
> > + description: phandle to the NFC SRAM block. Only applicable for atmel,sama5d3-nand-controller
> > +
> > +required:
> > + - compatible
> > + - ranges
> > + - "#address-cells"
> > + - "#size-cells"
> > +
> > +patternProperties:
> > + "^nand@[a-f0-9]$":
> > + type: object
> > + $ref: raw-nand-chip.yaml#
> > + description:
> > + NAND chip bindings.
> > +
> > + additionalProperties: false
> > +
> > + properties:
> > + reg:
> > + items:
> > + - items:
> > + - description: describes the CS lines assigned to the NAND device.
> > + - description: the base offset of the memory region assigned to this device (always 0)
> > + - description: the memory region size (always 0x800000)
> > + rb-gpios:
> > + description:
> > + the GPIO(s) used to check the Ready/Busy status of the NAND.
> > +
> > + cs-gpios:
> > + description:
> > + the GPIO(s) used to control the CS line.
> > +
> > + det-gpios:
> > + description:
> > + the GPIO used to detect if a Smartmedia Card is present.
> > +
> > + atmel,rb:
> > + description: |
Don't need '|'.
> > + an integer identifying the native Ready/Busy pin.
> > + $ref: /schemas/types.yaml#/definitions/uint32
Constraints? I'd assume there's a limit much lower than 2^32.
> > +
> > + nand-ecc-step-size:
> > + const: 512
> > +
> > + nand-ecc-strength:
> > + enum: [2, 4, 8]
> > +
> > + nand-ecc-mode:
> > + enum: [soft, hw]
> > +
> > + nand-bus-width:
> > + const: 8
> > +
> > + nand-on-flash-bbt: true
> > +
> > + partitions:
> > + $ref: /schemas/mtd/partitions/partitions.yaml
> > +
> > + label:
> > + description: Name or Label of the device
> > +
> > + allOf:
> > + - if:
> > + properties:
> > + compatible:
> > + contains:
> > + const: atmel,sama5d3-nand-controller
> > + then:
> > + properties:
> > + "atmel,rb":
> > + description: an integer identifying the native Ready/Busy pin.
This is wrong. This sub-schema applies to the 'nand' nodes, but
compatible is in the parent node for which the sub-schema has no
visibility. The 'if' is always true because 'compatible' is not present.
The 'then' is also always true. I would just drop the constraint.
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > + - |
> > + nfc_io: nfc-io at 70000000 {
> > + compatible = "atmel,sama5d3-nfc-io", "syscon";
> > + reg = <0x70000000 0x8000000>;
> > + };
> > +
> > + nfc_sram: sram at 200000 {
> > + compatible = "mmio-sram";
> > + no-memory-wc;
> > + reg = <0x200000 0x2400>;
> > + #address-cells = <1>;
> > + #size-cells = <1>;
> > + ranges = <0 0x200000 0x2400>;
> > + };
> > +
> > + ebi at 10000000 {
> > + compatible = "atmel,sama5d3-ebi";
> > + #address-cells = <2>;
> > + #size-cells = <1>;
> > + atmel,smc = <&hsmc>;
> > + reg = <0x10000000 0x10000000
> > + 0x40000000 0x30000000>;
> > + ranges = <0x0 0x0 0x10000000 0x10000000
> > + 0x1 0x0 0x40000000 0x10000000
> > + 0x2 0x0 0x50000000 0x10000000
> > + 0x3 0x0 0x60000000 0x10000000>;
> > + clocks = <&mck>;
> > +
> > + nand_controller: nand-controller {
> > + compatible = "atmel,sama5d3-nand-controller";
> > + atmel,nfc-sram = <&nfc_sram>;
> > + atmel,nfc-io = <&nfc_io>;
> > + ecc-engine = <&pmecc>;
> > + #address-cells = <2>;
> > + #size-cells = <1>;
> > + ranges;
I think this should be '<0x3 0x3 0x0>' to translate this from a EBI
chipselect to the nand chip chipselect.
> > +
> > + nand at 3 {
> > + reg = <0x3 0x0 0x800000>;
And then just 'reg = <3>;' here.
That assumes changing this would work with the existing driver.
Otherwise, we might need to add 'select: false' to nand-controller.yaml
and make sure all the controller schemas reference it (except this one).
Rob
More information about the linux-mtd
mailing list