Re: [PATCH 06/10] dt-bindings: ufs: Add compatibles for S32N79 Host Controller platform driver

On Thu, Aug 27, 2026 at 05:36:27PM +0300, Larisa Ileana Grigore wrote:
> On 8/26/2026 5:35 PM, Frank Li wrote:
> > On Wed, Aug 26, 2026 at 03:40:44PM +0200, Larisa Grigore wrote:
> > > [You don't often get email from [email protected]. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
> > >
> > > Document the device tree binding for the NXP S32N79 DWC-based UFS host
> > > controller which is compliant with JESD-223D "Universal Flash Storage Host
> > > Controller Interface" v3.0.
> > >
> > > The controller requires access to the SCM register block and the core
> > > clock rate when M-PHY initialization is performed. Add the optional
> > > nxp,mphy-boot-mode property to select the M-PHY firmware execution
> > > environment.
> > > Currently, the M-PHY firmware can only run from ROM. If the property is
> > > omitted, M-PHY initialization is assumed to be handled externally.
> > >
> > > Signed-off-by: Larisa Grigore <[email protected]>
> > > ---
> > >   .../bindings/ufs/nxp,s32n7-ufshc.yaml         | 99 +++++++++++++++++++
> > >   1 file changed, 99 insertions(+)
> > >   create mode 100644 Documentation/devicetree/bindings/ufs/nxp,s32n7-ufshc.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/ufs/nxp,s32n7-ufshc.yaml b/Documentation/devicetree/bindings/ufs/nxp,s32n7-ufshc.yaml
> > > new file mode 100644
> > > index 000000000000..d9d5669be313
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/ufs/nxp,s32n7-ufshc.yaml
> > > @@ -0,0 +1,99 @@
> > > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/ufs/nxp,s32n7-ufshc.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: NXP S32N79 Universal Flash Storage (UFS) Controller
> > > +
> > > +maintainers:
> > > +  - Larisa Grigore <[email protected]>
> > > +
> > > +# Select only our matches, not all jedec,ufs
> > > +select:
> > > +  properties:
> > > +    compatible:
> > > +      contains:
> > > +        const: nxp,s32n79-ufshc
> > > +  required:
> > > +    - compatible
> > > +
> > > +properties:
> > > +  compatible:
> > > +    items:
> > > +      - const: nxp,s32n79-ufshc
> > > +      - const: jedec,ufs-3.0
> >
> > Any place actually use this fallback?
>
> You're right Frank! I will switch to `jedec,ufs-2.0` in v2.
>
> >
> > > +
> > > +  reg:
> > > +    minItems: 1
> > > +    items:
> > > +      - description: UFS Host Controller registers
> > > +      - description: System Control Module registers
> > > +
> > > +  reg-names:
> > > +    description: |
> > > +      Names for the register regions. The first entry must be "ufshc".
> > > +      The second entry "scm" is mandatory only when nxp,mphy-boot-mode
> > > +      property is present.
> >
> > you already us if - else branch to restrict this limition, needn't
> > description here.
>
> Thank you! Will drop reg-names description in v2.
>
> > > +    minItems: 1
> > > +    items:
> > > +      - const: ufshc
> > > +      - const: scm
> > > +
> > > +  clocks:
> > > +    maxItems: 1
> > > +    description: UFS core clock
> > > +
> > > +  clock-names:
> > > +    items:
> > > +      - const: core_clk
> >
> > Needn't suffix _clk, just "core", generally needn't clock-names if only
> > one clocks.
>
> I will rename it to "core" in v2, if that works for you.
>
> > > +
> > > +  nxp,mphy-boot-mode:
> > > +    description: |
> > > +      MPHY initialization mode. Defines how the MPHY firmware should be
> > > +      initialized and executed during UFS controller startup.
> > > +      If this property is not specified, MPHY initialization will be skipped.
> > > +    $ref: /schemas/types.yaml#/definitions/string
> > > +    enum:
> > > +      - rom
> >
> > why not use standard "phy" property, if no "phy" means ROM init it.
>
> First, apologies for not including enough background in the commit message.
>
> On the S32N79, the M-PHY firmware can be brought up in one of three ways,
> selected through the SoC's SCM MPHY_RAM_CONFIG_STATUS register:
>
> 1. running MPHY from internal FW ROM,
> 2. running MPHY from a (modified) FW ROM copy in external SRAM, or
> 3. running MPHY from a FW image in external SRAM.
>
> `nxp,mphy-boot-mode` was introduced to select which of these boot sequences
> the controller driver programs. Today only option 1, "rom", is implemented
> and validated, but the property was meant to leave room for the two
> SRAM-based modes.


You need define all options in binding.  who load FW?

Frank

>
> Given this setup, what would you suggest as the appropriate DT
> representation? I would greatly appreciate any guidance you can provide.
>
> > Frank
> > > +
> > > +required:
> > > +  - compatible
> > > +  - reg
> > > +
> > > +allOf:
> > > +  - $ref: ufs-common.yaml
> > > +  - if:
> > > +      required:
> > > +        - nxp,mphy-boot-mode
> > > +    then:
> > > +      properties:
> > > +        reg:
> > > +          minItems: 2
> > > +        reg-names:
> > > +          minItems: 2
> > > +      required:
> > > +        - reg-names
> > > +        - clocks
> > > +        - clock-names
> > > +    else:
> > > +      properties:
> > > +        reg:
> > > +          maxItems: 1
> > > +        reg-names:
> > > +          maxItems: 1
> > > +
> > > +unevaluatedProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    ufshc@4ac80000 {
> > > +        compatible = "nxp,s32n79-ufshc", "jedec,ufs-3.0";
> > > +        reg = <0x4ac80000 0x1000>, <0x4ac40000 0x1000>;
> > > +        reg-names = "ufshc", "scm";
> > > +        interrupt-parent = <&irqsteer_coss>;
> > > +        interrupts = <211>;
> > > +        clocks = <&sys_clk>;
> > > +        clock-names = "core_clk";
> > > +        nxp,mphy-boot-mode = "rom";
> > > +    };
> > > --
> > > 2.43.0
> > >
> > >
>