Re: [PATCH v3 2/2] spi: meson-spicc: Use pinctrl to drive CLK line when idle

From: Neil Armstrong <neil.armstrong@linaro.org>
To: Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
	Amjad Ouled-Ameur <aouledameur@baylibre.com>
Cc: Mark Brown <broonie@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Jerome Brunet <jbrunet@baylibre.com>,
	Kevin Hilman <khilman@baylibre.com>,
	Rob Herring <robh+dt@kernel.org>, Da Xue <da@libre.computer>,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
	linux-amlogic@lists.infradead.org, linux-spi@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 2/2] spi: meson-spicc: Use pinctrl to drive CLK line when idle
Date: Thu, 20 Oct 2022 10:18:18 +0200	[thread overview]
Message-ID: <a6942e7a-faa5-d839-aebf-0d28e7e14f06@linaro.org> (raw)
In-Reply-To: <CAFBinCAsCg6QQRH3VPY1OKuyfkxY0oCXLhAuMwO6=00gXKqQrQ@mail.gmail.com>

On 19/10/2022 22:50, Martin Blumenstingl wrote:
> Hi Amjad,
> 
> On Wed, Oct 19, 2022 at 4:03 PM Amjad Ouled-Ameur
> <aouledameur@baylibre.com> wrote:
> [...]
>> diff --git a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
>> index c3ac531c4f84..04e9d0f1bde0 100644
>> --- a/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
>> +++ b/arch/arm64/boot/dts/amlogic/meson-gxl.dtsi
>> @@ -429,6 +429,20 @@ mux {
>>                          };
>>                  };
>>
>> +               spi_idle_high_pins: spi-idle-high-pins {
>> +                       mux {
>> +                               groups = "spi_sclk";
>> +                               bias-pull-up;
>> +                       };
>> +               };
>> +
>> +               spi_idle_low_pins: spi-idle-low-pins {
>> +                       mux {
>> +                               groups = "spi_sclk";
>> +                               bias-pull-down;
>> +                       };
>> +               };
>> +
> We typically have the .dts{,i} changes in a separate patch. I suggest
> doing the same here.
> I also have two questions about this part:
> - why are these not referenced by the SPICC controller node?

Because it's up to the board to use or not those states, if some pull-up/downs
are already present on the lines no need to use those special states.

> - is there a particular reason why meson-gxl.dtsi is updated but
> meson-gxbb.dtsi is not? (my understanding is that GXBB is also lacking
> hardware OEN support)

Good question indeed, so indeed they should be added in meson-gxbb.dtsi in a separate patch.
> 
> 
> Best regards,
> Martin

Thanks,
Neil