linux-kernel - Re: [PATCH v2 03/18] arm64: dts: mediatek: mt7988: add fixed regulators for 1v8 and 3v3

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Message-ID: <371B3F0C-D468-45C8-B1F6-F4619B7C72DD@public-files.de>
Date: Tue, 03 Dec 2024 11:51:54 +0100
From: Frank Wunderlich <frank-w@...lic-files.de>
To: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>,
 Frank Wunderlich <linux@...web.de>, Rob Herring <robh@...nel.org>,
 Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>,
 Matthias Brugger <matthias.bgg@...il.com>
CC: devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-arm-kernel@...ts.infradead.org, linux-mediatek@...ts.infradead.org
Subject: Re: [PATCH v2 03/18] arm64: dts: mediatek: mt7988: add fixed regulators for 1v8 and 3v3

Am 3. Dezember 2024 10:40:54 MEZ schrieb AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>:
>Il 02/12/24 13:25, Frank Wunderlich ha scritto:
>> From: Frank Wunderlich <frank-w@...lic-files.de>
>> 
>> Add regulator nodes used for mmc to Bananapi R4 board.
>> 
>> Signed-off-by: Frank Wunderlich <frank-w@...lic-files.de>
>
>If you're adding the eMMC regulators, I assume that there's an eMMC, or that even
>if there's no device in some version of the board, these two regulators are always
>assigned to the eMMC device - right?

Like BPi-R3 there is one mmc controller mapped to either sd or emmc. I can move the regulators to the dtbo,but then they are defined twice (at least 3v3).

>You should, at this point, do exactly that: you can leave the mmc0 disabled and
>only enable it in a DTBO.

I enable it only in dtbo...

>&mmc0 {
>	/* eMMC gets enabled by DTBO if present */
>	vmmc-supply = <&reg_3p3v>;
>	vqmmc-supply = <&reg_1p8v>;
>};

Problem is here that sdcard uses only the 3v3 twice

https://github.com/frank-w/BPI-Router-Linux/blob/6.12-main/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4-sd.dtso

And emmc needs both

https://github.com/frank-w/BPI-Router-Linux/blob/6.12-main/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4-emmc.dtso

Only defining the vmmc-supply in dts and set only the other in dtso is possible but but imho not nice.

>Cheers,
>Angelo
>
>> ---
>> v2:
>> - move mmc regulators to board dts of bpi-r4
>> ---
>>   .../dts/mediatek/mt7988a-bananapi-bpi-r4.dts   | 18 ++++++++++++++++++
>>   1 file changed, 18 insertions(+)
>> 
>> diff --git a/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dts b/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dts
>> index d914eae2b524..df53512c6890 100644
>> --- a/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dts
>> +++ b/arch/arm64/boot/dts/mediatek/mt7988a-bananapi-bpi-r4.dts
>> @@ -8,6 +8,24 @@ / {
>>   	compatible = "bananapi,bpi-r4", "mediatek,mt7988a";
>>   	model = "Banana Pi BPI-R4";
>>   	chassis-type = "embedded";
>> +
>> +	reg_1p8v: regulator-1p8v {
>> +		compatible = "regulator-fixed";
>> +		regulator-name = "fixed-1.8V";
>> +		regulator-min-microvolt = <1800000>;
>> +		regulator-max-microvolt = <1800000>;
>> +		regulator-boot-on;
>> +		regulator-always-on;
>> +	};
>> +
>> +	reg_3p3v: regulator-3p3v {
>> +		compatible = "regulator-fixed";
>> +		regulator-name = "fixed-3.3V";
>> +		regulator-min-microvolt = <3300000>;
>> +		regulator-max-microvolt = <3300000>;
>> +		regulator-boot-on;
>> +		regulator-always-on;
>> +	};
>>   };
>>     &pio {
>
>


regards Frank