Re: [PATCH v1] spi: dt-bindings: spi-rockchip: restrict num-cs

From: Johan Jonker <jbx6244@gmail.com>
To: Luis de Arquer <ldearquer@gmail.com>, broonie@kernel.org
Cc: robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
	conor+dt@kernel.org, heiko@sntech.de, linux-spi@vger.kernel.org,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-rockchip@lists.infradead.org
Subject: Re: [PATCH v1] spi: dt-bindings: spi-rockchip: restrict num-cs
Date: Tue, 23 Jan 2024 11:49:48 +0100	[thread overview]
Message-ID: <344a3de8-7f10-46f0-9524-dca58ceda671@gmail.com> (raw)
In-Reply-To: <d6fc0ad6-ce20-4604-89e5-2598dc3fc0a6@gmail.com>

On 1/23/24 10:17, Luis de Arquer wrote:
> On 1/22/24 23:59, Johan Jonker wrote:
>> In the driver spi-rockchip.c max_native_cs is limited to 4 and the
>> default num-cs property is 1. Restrict num-cs in spi-rockchip.yaml.
>>
> 

> Doesn't num-cs include gpio chip selects too?
> I have a setup with num-cs = <12> which uses non-native cs-gpios just fine

Given that bindings and Linux drivers capabilities are 2 separate things.
However this document has also a purpose that must notify mainline maintainers if users submit bogus DT values.
Currently that limit is set to 4 in the mainline driver.
You are free to submit a real board file/patch serie afterwords as proof for review with 12 spi chips and then adjust this limit and increase ROCKCHIP_SPI_MAX_CS_NUM.

Johan

> 
> Luis
> 
>> Signed-off-by: Johan Jonker <jbx6244@gmail.com>
>> ---
>>   Documentation/devicetree/bindings/spi/spi-rockchip.yaml | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/spi/spi-rockchip.yaml b/Documentation/devicetree/bindings/spi/spi-rockchip.yaml
>> index e4941e9212d1..00d555bcbad3 100644
>> --- a/Documentation/devicetree/bindings/spi/spi-rockchip.yaml
>> +++ b/Documentation/devicetree/bindings/spi/spi-rockchip.yaml
>> @@ -65,6 +65,11 @@ properties:
>>         - const: tx
>>         - const: rx
>>
>> +  num-cs:
>> +    default: 1
>> +    minimum: 1
>> +    maximum: 4
>> +
>>     rx-sample-delay-ns:
>>       default: 0
>>       description:
>> -- 
>> 2.39.2
>>
>>
>> _______________________________________________
>> Linux-rockchip mailing list
>> Linux-rockchip@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-rockchip
> 