Received-SPF: pass (google.com: domain of linux-kernel+bounces-70414-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Message-ID: <c7486f71-56ef-4ba8-9764-54245d906958@tuxon.dev>
Date: Sun, 18 Feb 2024 16:45:40 +0200
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v3 5/8] ARM: dts: microchip: sama5d27_wlsom1_ek: Add
 power-supply property for sdmmc0 node
Content-Language: en-US
To: Mihai Sain <mihai.sain@microchip.com>, robh+dt@kernel.org,
 krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
 nicolas.ferre@microchip.com, alexandre.belloni@bootlin.com,
 devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
 linux-kernel@vger.kernel.org
References: <20240206120322.88907-1-mihai.sain@microchip.com>
 <20240206120322.88907-6-mihai.sain@microchip.com>
From: claudiu beznea <claudiu.beznea@tuxon.dev>
In-Reply-To: <20240206120322.88907-6-mihai.sain@microchip.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit


On 06.02.2024 14:03, Mihai Sain wrote:
> The sdmmc0 controller is powered from 3.3V regulator.

Same here. SDMMC0 data lines are powered by VDDSDHC which could be 1v8/3v3.

[1]
https://ww1.microchip.com/downloads/aemDocuments/documents/MPU32/ProductDocuments/UserGuides/SAMA5D2-Wireless-SOM1-Kit-User%27s-Guide-50002931d.pdf

> Add vmmc-supply and vqmmc-supply properties to sdmmc0 node.
> The sdmmc controller from SAMA5D2 MPU has support for
> IO voltage signaling/switching required by the UHS sd-card.
> In order to avoid the issues from the tuning procedure required by
> the UHS cards, keep the vqmmc at 3V3 to use the sd high-speed mode.
> 
> Signed-off-by: Mihai Sain <mihai.sain@microchip.com>
> ---
>  arch/arm/boot/dts/microchip/at91-sama5d27_wlsom1_ek.dts | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/microchip/at91-sama5d27_wlsom1_ek.dts b/arch/arm/boot/dts/microchip/at91-sama5d27_wlsom1_ek.dts
> index 15239834d886..7b36e1970bb7 100644
> --- a/arch/arm/boot/dts/microchip/at91-sama5d27_wlsom1_ek.dts
> +++ b/arch/arm/boot/dts/microchip/at91-sama5d27_wlsom1_ek.dts
> @@ -199,6 +199,8 @@ &sdmmc0 {
>  	bus-width = <4>;
>  	pinctrl-names = "default";
>  	pinctrl-0 = <&pinctrl_sdmmc0_default>;
> +	vmmc-supply = <&vdd_3v3>;
> +	vqmmc-supply = <&vdd_3v3>;
>  	status = "okay";
>  };
>