Re: [PATCH 05/14] dt-bindings: gpio: Convert Broadcom STB GPIO to YAML

From: Florian Fainelli <f.fainelli@gmail.com>
To: Gregory Fong <gregory.0xf0@gmail.com>,
	Florian Fainelli <f.fainelli@gmail.com>
Cc: devicetree@vger.kernel.org,
	"Damien Le Moal" <damien.lemoal@opensource.wdc.com>,
	"Rob Herring" <robh+dt@kernel.org>,
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Subject: Re: [PATCH 05/14] dt-bindings: gpio: Convert Broadcom STB GPIO to YAML
Date: Thu, 2 Dec 2021 13:24:23 -0800	[thread overview]
Message-ID: <f96c346a-0d17-6148-0924-72744dd5c34d@gmail.com> (raw)
In-Reply-To: <CADtm3G7wiNdDq2fagWeSDd_RV_dyfrNy+5e-VL9OKjwGAWzNtg@mail.gmail.com>

On 12/2/21 8:00 AM, Gregory Fong wrote:
> Hi Florian,
> 
> I haven't kept up with the new yaml format, so not entirely sure I
> know what I'm talking about yet, but here are a few comments:
> 
> On Wed, Dec 1, 2021 at 12:51 PM Florian Fainelli <f.fainelli@gmail.com> wrote:
>>
>> Convert the Broadcom STB GPIO Device Tree binding to YAML to help with
>> validation.
>>
>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
>> ---
>>  .../bindings/gpio/brcm,brcmstb-gpio.txt       |  83 --------------
>>  .../bindings/gpio/brcm,brcmstb-gpio.yaml      | 104 ++++++++++++++++++
>>  MAINTAINERS                                   |   2 +-
>>  3 files changed, 105 insertions(+), 84 deletions(-)
>>  delete mode 100644 Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.txt
>>  create mode 100644 Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.txt b/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.txt
>> deleted file mode 100644
>> index 5d468ecd1809..000000000000
>> --- a/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.txt
>> +++ /dev/null
>> @@ -1,83 +0,0 @@
>> [snip]
>> -
>> -- interrupts-extended:
>> -    Alternate form of specifying interrupts and parents that allows for
>> -    multiple parents.  This takes precedence over 'interrupts' and
>> -    'interrupt-parent'.  Wakeup-capable GPIO controllers often route their
>> -    wakeup interrupt lines through a different interrupt controller than the
>> -    primary interrupt line, making this property necessary.
> 
> It looks like interrupts-extended was removed from the new docs, I'm
> assuming that was intentional?

Yes that is intentional, since this is a core property there is an
expectation that it is documented and used outside of the scope of this
binding.

> 
>> [snip]
>> diff --git a/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.yaml b/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.yaml
>> new file mode 100644
>> index 000000000000..4b7309dc74dc
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.yaml
>> @@ -0,0 +1,104 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/gpio/brcm,brcmstb-gpio.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Broadcom STB "UPG GIO" GPIO controller
>> +
>> +description: >
>> +  The controller's registers are organized as sets of eight 32-bit
>> +  registers with each set controlling a bank of up to 32 pins.  A single
>> +  interrupt is shared for all of the banks handled by the controller.
>> +
>> +maintainers:
>> +  - Doug Berger <opendmb@gmail.com>
>> +  - Florian Fainelli <f.fainelli@gmail.com>
>> +
>> +properties:
>> +  compatible:
>> +    oneOf:
>> +      - items:
>> +          - enum:
>> +              - brcm,bcm7445-gpio
>> +          - const: brcm,brcmstb-gpio
>> +
>> +  reg:
>> +    maxItems: 1
>> +    description:
> 
> Missing folded block scalar marker ('>') above

Done.

> 
>> +      Define the base and range of the I/O address space containing
>> +      the brcmstb GPIO controller registers
>> +
>> +  "#gpio-cells":
>> +    const: 2
>> +    description: >
>> +      The first cell is the pin number (within the controller's
>> +      pin space), and the second is used for the following:
>> +      bit[0]: polarity (0 for active-high, 1 for active-low)
>> +
>> +  gpio-controller: true
>> +
>> +  "brcm,gpio-bank-widths":
>> +    $ref: /schemas/types.yaml#/definitions/uint32-array
>> +    description:
> 
> Same here
> 
>> +      Number of GPIO lines for each bank.  Number of elements must
>> +      correspond to number of banks suggested by the 'reg' property.
>> +
>> +  interrupts:
>> +    maxItems: 1
>> +    description:
> 
> While it's not necessary while this is only one line, consider adding
> '>' here too.
> 
>> +      The interrupt shared by all GPIO lines for this controller.
>> +
>> +  "#interrupt-cells":
>> +    const: 2
>> +    description: >
> 
> This next block could get formatted strangely with '>'; recommend
> using '|' instead

Yes good point.

> 
>> +      The first cell is the GPIO number, the second should specify
>> +      flags.  The following subset of flags is supported:
>> +      - bits[3:0] trigger type and level flags
>> +        1 = low-to-high edge triggered
>> +        2 = high-to-low edge triggered
>> +        4 = active high level-sensitive
>> +        8 = active low level-sensitive
>> +      Valid combinations are 1, 2, 3, 4, 8.
>> +
>> +  interrupt-controller: true
>> +
>> +  wakeup-source:
>> +    type: boolean
>> +    description: >
>> +      GPIOs for this controller can be used as a wakeup source
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - gpio-controller
>> +  - "#gpio-cells"
> 
> Need to add required property "brcm,gpio-bank-widths"

Indeed, done.

> 
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    upg_gio: gpio@f040a700 {
>> +        #gpio-cells = <2>;
>> +        #interrupt-cells = <2>;
>> +        compatible = "brcm,bcm7445-gpio", "brcm,brcmstb-gpio";
>> +        gpio-controller;
>> +        interrupt-controller;
>> +        reg = <0xf040a700 0x80>;
>> +        interrupt-parent = <&irq0_intc>;
>> +        interrupts = <0x6>;
>> +        brcm,gpio-bank-widths = <32 32 32 24>;
>> +    };
>> +
>> +    upg_gio_aon: gpio@f04172c0 {
>> +        #gpio-cells = <2>;
>> +        #interrupt-cells = <2>;
>> +        compatible = "brcm,bcm7445-gpio", "brcm,brcmstb-gpio";
>> +        gpio-controller;
>> +        interrupt-controller;
>> +        reg = <0xf04172c0 0x40>;
>> +        interrupt-parent = <&irq0_aon_intc>;
>> +        interrupts = <0x6>;
>> +        wakeup-source;
>> +        brcm,gpio-bank-widths = <18 4>;
>> +    };
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 913856599623..78161abc384f 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -3772,7 +3772,7 @@ BROADCOM BRCMSTB GPIO DRIVER
>>  M:     Gregory Fong <gregory.0xf0@gmail.com>
> 
> Not really related to this patch, but I should probably update this
> entry to reflect current reality. Should that be you and/or Doug?

If you could add both of us that would be great, thanks!
-- 
Florian