Re: [PATCH v6 1/4] dt-bindings: mtd: renesas: Describe Renesas R-Car Gen3 & RZ/N1 NAND controller

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hi Geert,

geert@linux-m68k.org wrote on Fri, 17 Dec 2021 16:44:59 +0100:

> Hi Miquel,
> 
> On Fri, Dec 17, 2021 at 3:20 PM Miquel Raynal <miquel.raynal@bootlin.com> wrote:
> > Add a Yaml description for this Renesas NAND controller.
> >
> > As this controller is embedded on different SoC families, provide:
> > * a family-specific "r-car-gen3" compatible and a more specific
> >   "r8a77951" one
> > * a family-specific "rzn1" compatible and a more specific "r9a06g032"
> >   one
> >
> > More compatibles can be added later if new SoCs with this controller
> > must be supported.
> >
> > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> > Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> > Reviewed-by: Rob Herring <robh@kernel.org>  
> 
> Thanks for the update!
> 
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mtd/renesas-nandc.yaml
> > @@ -0,0 +1,66 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/mtd/renesas-nandc.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Renesas R-Car Gen3 & RZ/N1x NAND flash controller device tree bindings
> > +
> > +maintainers:
> > +  - Miquel Raynal <miquel.raynal@bootlin.com>
> > +
> > +allOf:
> > +  - $ref: "nand-controller.yaml"
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
> > +      - items:
> > +          - enum:
> > +              - renesas,r8a77951-nandc
> > +          - const: renesas,rcar-gen3-nandc  
> 
> Might be a bit premature to add these before they have been tested,
> and because there are small differences in integration, cfr. below.
> 
> > +
> > +      - items:
> > +          - enum:
> > +              - renesas,r9a06g032-nandc
> > +          - const: renesas,rzn1-nandc
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    items:
> > +      - description: APB host controller clock
> > +      - description: External NAND bus clock
> > +
> > +  clock-names:
> > +    items:
> > +      - const: hclk
> > +      - const: eclk  
> 
> On R-Car Gen3, there's a single module clock.
> Plus a power-domain to manage that.
> 
> Actually the RZ/N1 clock driver also registers a PM Domain, so letting
> Runtime PM manage the clocks may work on RZ/N1, too...
> 
> On R-Car Gen3, there's also a module reset.

Ok, I didn't know. I propose to drop the r-car-gen3 compatible entirely
from the driver and the binding when I'll apply the series. Is it fine
for you?

> 
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - clocks
> > +  - clock-names
> > +  - interrupts
> > +
> > +unevaluatedProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +    #include <dt-bindings/clock/r9a06g032-sysctrl.h>
> > +
> > +    nand-controller@40102000 {
> > +        compatible = "renesas,r9a06g032-nandc", "renesas,rzn1-nandc";
> > +        reg = <0x40102000 0x2000>;
> > +        interrupts = <GIC_SPI 58 IRQ_TYPE_LEVEL_HIGH>;
> > +        clocks = <&sysctrl R9A06G032_HCLK_NAND>, <&sysctrl R9A06G032_CLK_NAND>;
> > +        clock-names = "hclk", "eclk";
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +    };  
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds


Thanks,
Miquèl