Re: [PATCH v14 07/16] dt-bindings: fix sifive gpio properties

From: Sean Anderson <seanga2@gmail.com>
To: Atish Patra <atishp@atishpatra.org>,
	Damien Le Moal <damien.lemoal@wdc.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>,
	linux-riscv <linux-riscv@lists.infradead.org>,
	devicetree <devicetree@vger.kernel.org>,
	Rob Herring <robh@kernel.org>, Anup Patel <anup.patel@wdc.com>,
	Atish Patra <atish.patra@wdc.com>,
	Paul Walmsley <paul.walmsley@sifive.com>
Subject: Re: [PATCH v14 07/16] dt-bindings: fix sifive gpio properties
Date: Tue, 2 Feb 2021 18:54:07 -0500	[thread overview]
Message-ID: <5d565fe4-f624-ea28-177b-2fe01a678260@gmail.com> (raw)
In-Reply-To: <CAOnJCUKQ+yFJN9+biMMQW6Wvf=eckfcfMHVpDB74TmxWVNoEkQ@mail.gmail.com>

On 2/2/21 1:45 PM, Atish Patra wrote:
> On Tue, Feb 2, 2021 at 2:37 AM Damien Le Moal <damien.lemoal@wdc.com> wrote:
>>
>> The sifive gpio IP block supports up to 32 GPIOs. Reflect that in the
> 
> The spec here says 16 GPIOs
> https://static.dev.sifive.com/FU540-C000-v1.0.pdf
> 
> Is there a updated spec available ?

This GPIO device is (AFAICT) from [1]. While the version instantiated on
SiFive's cores has 16 GPIOs, the actual number of GPIOs is configurable. In
Canaan's version, there are 32 GPIOs. Unfortunately, I am not aware of any
non-implementation-specific documentation for this device.

--Sean

[1] https://github.com/sifive/sifive-blocks/tree/master/src/main/scala/devices/gpio

> 
>> interrupts property description and maxItems. Also add the standard
>> ngpios property to describe the number of GPIOs available on the
>> implementation.
>>
>> Also add the "canaan,k210-gpiohs" compatible string to indicate the use
>> of this gpio controller in the Canaan Kendryte K210 SoC. If this
>> compatible string is used, do not define the clocks property as
>> required as the K210 SoC does not have a software controllable clock
>> for the Sifive gpio IP block.
>>
>> Cc: Paul Walmsley <paul.walmsley@sifive.com>
>> Cc: Rob Herring <robh@kernel.org>
>> Cc: devicetree@vger.kernel.org
>> Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
>> ---
>>   .../devicetree/bindings/gpio/sifive,gpio.yaml | 21 ++++++++++++++++---
>>   1 file changed, 18 insertions(+), 3 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml b/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml
>> index ab22056f8b44..2cef18ca737c 100644
>> --- a/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml
>> +++ b/Documentation/devicetree/bindings/gpio/sifive,gpio.yaml
>> @@ -16,6 +16,7 @@ properties:
>>         - enum:
>>             - sifive,fu540-c000-gpio
>>             - sifive,fu740-c000-gpio
>> +          - canaan,k210-gpiohs
>>         - const: sifive,gpio0
>>
>>     reg:
>> @@ -23,9 +24,9 @@ properties:
>>
>>     interrupts:
>>       description:
>> -      interrupt mapping one per GPIO. Maximum 16 GPIOs.
>> +      interrupt mapping one per GPIO. Maximum 32 GPIOs.
>>       minItems: 1
>> -    maxItems: 16
>> +    maxItems: 32
>>
>>     interrupt-controller: true
>>
>> @@ -38,6 +39,10 @@ properties:
>>     "#gpio-cells":
>>       const: 2
>>
>> +  ngpios:
>> +    minimum: 1
>> +    maximum: 32
>> +
>>     gpio-controller: true
>>
>>   required:
>> @@ -46,10 +51,20 @@ required:
>>     - interrupts
>>     - interrupt-controller
>>     - "#interrupt-cells"
>> -  - clocks
>>     - "#gpio-cells"
>>     - gpio-controller
>>
>> +if:
>> +  properties:
>> +    compatible:
>> +      contains:
>> +        enum:
>> +          - sifive,fu540-c000-gpio
>> +          - sifive,fu740-c000-gpio
>> +then:
>> +  required:
>> +    - clocks
>> +
>>   additionalProperties: false
>>
>>   examples:
>> --
>> 2.29.2
>>
>>
>> _______________________________________________
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>> linux-riscv@lists.infradead.org
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> 
> 
> 