Re: [PATCH 05/12] dt-bindings: mtd: brcmnand: Updates for bcmbca SoCs

Miquel Raynal
2023-06-07T08:15:04Z

Hi William,

william.zhang@broadcom.com wrote on Tue, 6 Jun 2023 16:12:45 -0700:

> Use new compatiable brcm,nand-bcmbca to support BCMBCA broadband
> product. The old compatible string is still kept in the driver so old
> dtb can still work.
>
> Add brcm,nand-use-wp property to have an option for disabling this
> feature on broadband board design that does not use write protection.
> Add brcm,nand-ecc-use-strap to get ecc setting from board strap for
> broadband board designs because they do not specify ecc setting in dts
> but rather using the strap setting.
>
> Remove the requirement of interrupts and interrupt-names properties to
> reflect the driver code.
>
> This patch also includes a few minor fixes to the BCM63xx compatibles
> and add myself to the list of maintainers.
>
> Signed-off-by: William Zhang <william.zhang@broadcom.com>
> ---
>
> .../bindings/mtd/brcm,brcmnand.yaml | 64 +++++++++++++------
> 1 file changed, 43 insertions(+), 21 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mtd/brcm,brcmnand.yaml b/Documentation/devicetree/bindings/mtd/brcm,brcmnand.yaml
> index 1571024aa119..1fe1c166a9db 100644
> --- a/Documentation/devicetree/bindings/mtd/brcm,brcmnand.yaml
> +++ b/Documentation/devicetree/bindings/mtd/brcm,brcmnand.yaml
> @@ -9,6 +9,7 @@ title: Broadcom STB NAND Controller
> maintainers:
> - Brian Norris <computersforpeace@gmail.com>
> - Kamal Dasu <kdasu.kdev@gmail.com>
> + - William Zhang <william.zhang@broadcom.com>
>
> description: |
> The Broadcom Set-Top Box NAND controller supports low-level access to raw NAND
> @@ -18,9 +19,10 @@ description: |
> supports basic PROGRAM and READ functions, among other features.
>
> This controller was originally designed for STB SoCs (BCM7xxx) but is now
> - available on a variety of Broadcom SoCs, including some BCM3xxx, BCM63xx, and
> - iProc/Cygnus. Its history includes several similar (but not fully register
> - compatible) versions.
> + available on a variety of Broadcom SoCs, including some BCM3xxx, MIPS based
> + Broadband SoC (BCM63xx), ARM based Broadband SoC (BCMBCA) and iProc/Cygnus.
> + Its history includes several similar (but not fully register compatible)
> + versions.
>
> -- Additional SoC-specific NAND controller properties --
>
> @@ -53,9 +55,9 @@ properties:
> - brcm,brcmnand-v7.2
> - brcm,brcmnand-v7.3
> - const: brcm,brcmnand
> - - description: BCM63138 SoC-specific NAND controller
> + - description: BCMBCA SoC-specific NAND controller
> items:
> - - const: brcm,nand-bcm63138
> + - const: brcm,nand-bcmbca
> - enum:
> - brcm,brcmnand-v7.0
> - brcm,brcmnand-v7.1
> @@ -65,11 +67,15 @@ properties:
> - const: brcm,nand-iproc
> - const: brcm,brcmnand-v6.1
> - const: brcm,brcmnand
> - - description: BCM63168 SoC-specific NAND controller
> + - description: BCM63xx SoC-specific NAND controller
> items:
> - - const: brcm,nand-bcm63168
> - - const: brcm,nand-bcm6368
> - - const: brcm,brcmnand-v4.0
> + - enum:
> + - brcm,nand-bcm63168
> + - brcm,nand-bcm6368
> + - enum:
> + - brcm,brcmnand-v2.1
> + - brcm,brcmnand-v2.2
> + - brcm,brcmnand-v4.0
> - const: brcm,brcmnand
>
> reg:
> @@ -111,6 +117,19 @@ properties:
> earlier versions of this core that include WP
> type: boolean
>
> + brcm,nand-use-wp:
> + description:
> + Use this integer to indicate if board design uses
> + controller's write protection feature and connects its
> + NAND_WPb pin to nand chip's WP_L pin. Driver defaults to
> + use this feature when this property does not exist.
> + Set to 0 if WP pins are not connected and feature is not
> + used. Set to 1 if WP pins are connected and feature is used.
> + Set to 2 if WP pins are connected but disable this feature
> + through driver that sets controller to output high on NAND_WPb.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + enum: [0, 1, 2]

Perhaps strings would be welcome. I'll let binding maintainers say what
they think of it.

> +
> patternProperties:
> "^nand@[a-f0-9]$":
> type: object
> @@ -136,13 +155,23 @@ patternProperties:
> layout.
> $ref: /schemas/types.yaml#/definitions/uint32
>
> + brcm,nand-ecc-use-strap:
> + description:
> + This flag is used by the driver to get the ecc strength and
> + spare area size from the SoC NAND boot strap setting. This
> + is commonly used by the BCMBCA SoC board design. If ecc
> + strength and spare area size are set by nand-ecc-strength
> + and brcm,nand-oob-sector-size in the dts, these settings
> + have precedence and override this flag.
> + $ref: /schemas/types.yaml#/definitions/flag

How in practice do you access the strap value? Don't you need a phandle
over a specific area in the SoC?

> +
> allOf:
> - $ref: nand-controller.yaml#
> - if:
> properties:
> compatible:
> contains:
> - const: brcm,nand-bcm63138
> + const: brcm,nand-bcmbca
> then:
> properties:
> reg-names:
> @@ -153,7 +182,9 @@ allOf:
> properties:
> compatible:
> contains:
> - const: brcm,nand-bcm6368
> + enum:
> + - brcm,nand-bcm63168
> + - brcm,nand-bcm6368
> then:
> properties:
> reg-names:
> @@ -173,20 +204,12 @@ allOf:
> - const: nand
> - const: iproc-idm
> - const: iproc-ext
> - - if:
> - properties:
> - interrupts:
> - minItems: 2
> - then:
> - required:
> - - interrupt-names

Why do you remove this? Removing "interrupts" from the required
properties is fine, but constraining the interrupts property when it is
relevant is still expected.

>
> unevaluatedProperties: false
>
> required:
> - reg
> - reg-names
> - - interrupts

This should be done in a separate patch.

>
> examples:
> - |
> @@ -215,8 +238,7 @@ examples:
> };
> - |
> nand-controller@10000200 {
> - compatible = "brcm,nand-bcm63168", "brcm,nand-bcm6368",
> - "brcm,brcmnand-v4.0", "brcm,brcmnand";
> + compatible = "brcm,nand-bcm6368", "brcm,brcmnand-v2.1", "brcm,brcmnand";
> reg = <0x10000200 0x180>,
> <0x100000b0 0x10>,
> <0x10000600 0x200>;

Thanks,
Miquèl