Re: [PATCH v2 1/2] dt-bindings: pinctrl: Add DT bindings for apple,pinctrl

[Mark Kettenis <mark.kettenis@xs4all.nl>]

> Date: Tue, 18 May 2021 08:43:56 -0500
> From: Rob Herring <robh@kernel.org>
> 
> On Sun, May 16, 2021 at 08:32:17PM +0200, Mark Kettenis wrote:
> > From: Mark Kettenis <kettenis@openbsd.org>
> > 
> > The Apple GPIO controller is a simple combined pin and GPIO conroller
> > present on Apple ARM SoC platforms, including various iPhone and iPad
> > devices and the "Apple Silicon" Macs.
> > 
> > Signed-off-by: Mark Kettenis <kettenis@openbsd.org>
> > ---
> >  .../bindings/pinctrl/apple,pinctrl.yaml       | 103 ++++++++++++++++++
> >  MAINTAINERS                                   |   2 +
> >  include/dt-bindings/pinctrl/apple.h           |  13 +++
> >  3 files changed, 118 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
> >  create mode 100644 include/dt-bindings/pinctrl/apple.h
> > 
> > diff --git a/Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
> > new file mode 100644
> > index 000000000000..fae23e1d845e
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
> > @@ -0,0 +1,103 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pinctrl/apple,pinctrl.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Apple GPIO controller
> > +
> > +maintainers:
> > +  - Mark Kettenis <kettenis@openbsd.org>
> > +
> > +description: |
> > +  The Apple GPIO controller is a simple combined pin and GPIO
> > +  controller present on Apple ARM SoC platforms, including various
> > +  iPhone and iPad devices and the "Apple Silicon" Macs.
> > +
> > +properties:
> > +  compatible:
> > +    items:
> > +      - const: apple,t8103-pinctrl
> > +      - const: apple,pinctrl
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    maxItems: 1
> > +
> > +  gpio-controller: true
> > +
> > +  '#gpio-cells':
> > +    const: 2
> > +
> > +  gpio-ranges:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    minItems: 1
> > +    maxItems: 7
> 
> Add some description about what each interrupt is.

Will do.  This aspect of the hardware is somewhat interesting.  Pins
can be assigned to one of (up to 7) interrupt groups, each with their
own interrupt.

> Is this really 1-7 or either 1 or 7?

The intention is 1-7, to cater for the case where less than 7
interrupt groups are supported by a particular instance of this
hardware block.  For the M1, it seems there always are 7 interrupt
groups, but I found a device tree for the iBridge2,1 where one of the
instances only supports 3 interrupt groups and therefore only provides
three interrupts.

> > +
> > +  interrupt-controller: true
> > +
> > +patternProperties:
> > +  '-pins$':
> > +    type: object
> > +    $ref: pinmux-node.yaml#
> > +
> > +    properties:
> > +      pinmux:
> > +        description:
> > +          Values are constructed from pin number and alternate function
> > +          configuration number using the APPLE_PINMUX() helper macro
> > +          defined in include/dt-bindings/pinctrl/apple.h.
> > +
> > +    required:
> > +      - pinmux
> > +
> > +    additionalProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - gpio-controller
> > +  - '#gpio-cells'
> > +  - gpio-ranges
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/apple-aic.h>
> > +    #include <dt-bindings/pinctrl/apple.h>
> > +
> > +    soc {
> > +      #address-cells = <2>;
> > +      #size-cells = <2>;
> > +
> > +      pinctrl: pinctrl@23c100000 {
> > +        compatible = "apple,t8103-pinctrl", "apple,pinctrl";
> > +        reg = <0x2 0x3c100000 0x0 0x100000>;
> > +        clocks = <&gpio_clk>;
> > +
> > +        gpio-controller;
> > +        #gpio-cells = <2>;
> > +        gpio-ranges = <&pinctrl 0 0 212>;
> > +
> > +        interrupt-controller;
> > +        interrupt-parent = <&aic>;
> > +        interrupts = <AIC_IRQ 16 IRQ_TYPE_LEVEL_HIGH>,
> > +                     <AIC_IRQ 17 IRQ_TYPE_LEVEL_HIGH>,
> > +                     <AIC_IRQ 18 IRQ_TYPE_LEVEL_HIGH>,
> > +                     <AIC_IRQ 19 IRQ_TYPE_LEVEL_HIGH>,
> > +                     <AIC_IRQ 20 IRQ_TYPE_LEVEL_HIGH>,
> > +                     <AIC_IRQ 21 IRQ_TYPE_LEVEL_HIGH>,
> > +                     <AIC_IRQ 22 IRQ_TYPE_LEVEL_HIGH>;
> > +
> > +        pcie_pins: pcie-pins {
> > +          pinmux = <APPLE_PINMUX(150, 1)>,
> > +                   <APPLE_PINMUX(151, 1)>,
> > +                   <APPLE_PINMUX(32, 1)>;
> > +        };
> > +      };
> > +    };
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index ad0e9be66885..7327c9b778f1 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -1654,9 +1654,11 @@ C:	irc://chat.freenode.net/asahi-dev
> >  T:	git https://github.com/AsahiLinux/linux.git
> >  F:	Documentation/devicetree/bindings/arm/apple.yaml
> >  F:	Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml
> > +F:	Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
> >  F:	arch/arm64/boot/dts/apple/
> >  F:	drivers/irqchip/irq-apple-aic.c
> >  F:	include/dt-bindings/interrupt-controller/apple-aic.h
> > +F:	include/dt-bindings/pinctrl/apple.h
> >  
> >  ARM/ARTPEC MACHINE SUPPORT
> >  M:	Jesper Nilsson <jesper.nilsson@axis.com>
> > diff --git a/include/dt-bindings/pinctrl/apple.h b/include/dt-bindings/pinctrl/apple.h
> > new file mode 100644
> > index 000000000000..ea0a6f466592
> > --- /dev/null
> > +++ b/include/dt-bindings/pinctrl/apple.h
> > @@ -0,0 +1,13 @@
> > +/* SPDX-License-Identifier: GPL-2.0+ OR MIT */
> > +/*
> > + * This header provides constants for Apple pinctrl bindings.
> > + */
> > +
> > +#ifndef _DT_BINDINGS_PINCTRL_APPLE_H
> > +#define _DT_BINDINGS_PINCTRL_APPLE_H
> > +
> > +#define APPLE_PINMUX(pin, func) ((pin) | ((func) << 16))
> > +#define APPLE_PIN(pinmux) ((pinmux) & 0xffff)
> > +#define APPLE_FUNC(pinmux) ((pinmux) >> 16)
> > +
> > +#endif /* _DT_BINDINGS_PINCTRL_APPLE_H */
> > -- 
> > 2.31.1
> > 
>