Re: [PATCH v5 06/39] dt-bindings: soc: Add Cirrus EP93xx

[Nikita Shubin <nikita.shubin@maquefel.me>]

Hello Robert!

On Mon, 2023-11-27 at 14:18 -0600, Rob Herring wrote:
> On Wed, Nov 22, 2023 at 11:59:44AM +0300, Nikita Shubin wrote:
> > Add device tree bindings for the Cirrus Logic EP93xx SoC.
> > 
> > Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
> > ---
> >  .../bindings/arm/cirrus/cirrus,ep9301.yaml         | 38 ++++++++++
> 
> >  .../bindings/soc/cirrus/cirrus,ep9301-syscon.yaml  | 83
> > ++++++++++++++++++++++
> >  include/dt-bindings/soc/cirrus,ep9301-syscon.h     | 46
> > ++++++++++++
> 
> This looks like it is mostly clocks. I'd put it in bindings/clock/
> and 
> include/dt-bindings/clock/ instead.
> 
> >  3 files changed, 167 insertions(+)
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/arm/cirrus/cirrus,ep9301.yaml
> > b/Documentation/devicetree/bindings/arm/cirrus/cirrus,ep9301.yaml
> > new file mode 100644
> > index 000000000000..97dd8b6aefa9
> > --- /dev/null
> > +++
> > b/Documentation/devicetree/bindings/arm/cirrus/cirrus,ep9301.yaml
> > @@ -0,0 +1,38 @@
> > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/arm/cirrus/cirrus,ep9301.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Cirrus Logic EP93xx platforms
> > +
> > +description:
> > +  The EP93xx SoC is a ARMv4T-based with 200 MHz ARM9 CPU.
> > +
> > +maintainers:
> > +  - Alexander Sverdlin <alexander.sverdlin@gmail.com>
> > +  - Nikita Shubin <nikita.shubin@maquefel.me>
> > +
> > +properties:
> > +  $nodename:
> > +    const: '/'
> > +  compatible:
> > +    oneOf:
> > +      - description: The TS-7250 is a compact, full-featured
> > Single Board Computer (SBC)
> > +          based upon the Cirrus EP9302 ARM9 CPU
> 
> Wrap lines at 80 unless there's some advantage to going to 100. Here 
> there is not.
> 
> > +        items:
> > +          - const: technologic,ts7250
> > +          - const: cirrus,ep9301
> > +
> > +      - description: The Liebherr BK3 is a derivate from ts7250
> > board
> > +        items:
> > +          - const: liebherr,bk3
> > +          - const: cirrus,ep9301
> > +
> > +      - description: EDB302 is an evaluation board by Cirrus
> > Logic,
> > +          based on a Cirrus Logic EP9302 CPU
> > +        items:
> > +          - const: cirrus,edb9302
> > +          - const: cirrus,ep9301
> > +
> > +additionalProperties: true
> > diff --git
> > a/Documentation/devicetree/bindings/soc/cirrus/cirrus,ep9301-
> > syscon.yaml
> > b/Documentation/devicetree/bindings/soc/cirrus/cirrus,ep9301-
> > syscon.yaml
> > new file mode 100644
> > index 000000000000..283cf2386d95
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/soc/cirrus/cirrus,ep9301-
> > syscon.yaml
> > @@ -0,0 +1,83 @@
> > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> > +%YAML 1.2
> > +---
> > +$id:
> > http://devicetree.org/schemas/soc/cirrus/cirrus,ep9301-syscon.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Cirrus Logic EP93xx Platforms System Controller
> > +
> > +maintainers:
> > +  - Alexander Sverdlin <alexander.sverdlin@gmail.com>
> > +  - Nikita Shubin <nikita.shubin@maquefel.me>
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
> > +      - items:
> > +          - enum:
> > +              - cirrus,ep9302-syscon
> > +              - cirrus,ep9307-syscon
> > +              - cirrus,ep9312-syscon
> > +              - cirrus,ep9315-syscon
> 
> The registers of these are all the same as (or a superset of) the 
> EP9301? That's what you are claiming. Perhaps already discussed, but 
> there's no blurb here to explain the relationship.
> 
> 'syscon' is a Linux term. Is this block really called this?

Citing documentation:

"The System Controller (Syscon) provides:
• Clock control
• Power management
• System configuration management
These central resources are controlled by a set of software-locked
registers, which can be
used to prevent accidental accesses. Syscon generates the various bus
and peripheral
clocks and controls the system startup configuration."

I'll put the following into description:

"Central resources are controlled by a set of software-locked
registers, which can be used to prevent accidental accesses. Syscon
generates the various bus and peripheral clocks and controls the system
startup configuration.

  The System Controller (Syscon) provides:
  - Clock control
  - Power management
  - System configuration management

Syscon registers are common for all EP93xx SoC's, through some actual
peripheral may be missing depending on actual SoC model."

> 
> > +          - const: cirrus,ep9301-syscon
> > +          - const: syscon
> > +          - const: simple-mfd
> > +      - items:
> > +          - const: cirrus,ep9301-syscon
> > +          - const: syscon
> > +          - const: simple-mfd
> 
> Doesn't look like an simple-mfd to me. You don't have independent
> child 
> blocks which don't depend on the parent node.
> 
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  "#clock-cells":
> > +    const: 1
> > +
> > +  clocks:
> > +    items:
> > +      - description: reference clock
> > +
> > +patternProperties:
> > +  '^pins-':
> > +    type: object
> > +    description: pin node
> > +    $ref: /schemas/pinctrl/pinmux-node.yaml
> > +
> > +    properties:
> > +      function:
> > +        enum: [ spi, ac97, i2s, pwm, keypad, pata, lcd, gpio ]
> > +
> > +      groups:
> > +        enum: [ ssp, ac97, i2s_on_ssp, i2s_on_ac97, pwm1,
> > gpio1agrp,
> > +                gpio2agrp, gpio3agrp, gpio4agrp, gpio6agrp,
> > gpio7agrp,
> > +                rasteronsdram0grp, rasteronsdram3grp, keypadgrp,
> > idegrp ]
> > +
> > +    required:
> > +      - function
> > +      - groups
> > +
> > +    unevaluatedProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - "#clock-cells"
> > +  - clocks
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    syscon@80930000 {
> > +      compatible = "cirrus,ep9301-syscon",
> > +                   "syscon", "simple-mfd";
> > +      reg = <0x80930000 0x1000>;
> > +
> > +      #clock-cells = <1>;
> > +      clocks = <&xtali>;
> > +
> > +      spi_default_pins: pins-spi {
> > +        function = "spi";
> > +        groups = "ssp";
> > +      };
> > +    };
> > diff --git a/include/dt-bindings/soc/cirrus,ep9301-syscon.h
> > b/include/dt-bindings/soc/cirrus,ep9301-syscon.h
> > new file mode 100644
> > index 000000000000..6bb8f532e7d0
> > --- /dev/null
> > +++ b/include/dt-bindings/soc/cirrus,ep9301-syscon.h
> > @@ -0,0 +1,46 @@
> > +/* SPDX-License-Identifier: (GPL-2.0 OR MIT) */
> > +#ifndef DT_BINDINGS_CIRRUS_EP93XX_CLOCK_H
> > +#define DT_BINDINGS_CIRRUS_EP93XX_CLOCK_H
> > +
> > +#define EP93XX_CLK_PLL1                0
> > +#define EP93XX_CLK_PLL2                1
> > +
> > +#define EP93XX_CLK_FCLK                2
> > +#define EP93XX_CLK_HCLK                3
> > +#define EP93XX_CLK_PCLK                4
> > +
> > +#define EP93XX_CLK_UART                5
> > +#define EP93XX_CLK_SPI         6
> > +#define EP93XX_CLK_PWM         7
> > +#define EP93XX_CLK_USB         8
> > +
> > +#define EP93XX_CLK_M2M0                9
> > +#define EP93XX_CLK_M2M1                10
> > +
> > +#define EP93XX_CLK_M2P0                11
> > +#define EP93XX_CLK_M2P1                12
> > +#define EP93XX_CLK_M2P2                13
> > +#define EP93XX_CLK_M2P3                14
> > +#define EP93XX_CLK_M2P4                15
> > +#define EP93XX_CLK_M2P5                16
> > +#define EP93XX_CLK_M2P6                17
> > +#define EP93XX_CLK_M2P7                18
> > +#define EP93XX_CLK_M2P8                19
> > +#define EP93XX_CLK_M2P9                20
> > +
> > +#define EP93XX_CLK_UART1       21
> > +#define EP93XX_CLK_UART2       22
> > +#define EP93XX_CLK_UART3       23
> > +
> > +#define EP93XX_CLK_ADC         24
> > +#define EP93XX_CLK_ADC_EN      25
> > +
> > +#define EP93XX_CLK_KEYPAD      26
> > +
> > +#define EP93XX_CLK_VIDEO       27
> > +
> > +#define EP93XX_CLK_I2S_MCLK    28
> > +#define EP93XX_CLK_I2S_SCLK    29
> > +#define EP93XX_CLK_I2S_LRCLK   30
> > +
> > +#endif /* DT_BINDINGS_CIRRUS_EP93XX_CLOCK_H */
> > 
> > -- 
> > 2.41.0
> >