Re: [PATCH 2/3] arm64: dts: qcom: monaco-evk: Enable SDHCI for SD Card via overlay

[Konrad Dybcio]

On 3/2/26 3:24 PM, Monish Chunara wrote:
> On Fri, Feb 27, 2026 at 10:03:10PM +0200, Dmitry Baryshkov wrote:
>> On Fri, Feb 27, 2026 at 04:20:54PM +0530, Monish Chunara wrote:
>>> The monaco EVK board supports either eMMC or SD-card, but only one
>>> can be active at a time.
>>>
>>> Enable the SD Host Controller Interface (SDHCI) on the monaco EVK board
>>> to support SD Card for storage via a device tree overlay. This allows
>>> eMMC support to be enabled through a separate overlay when required.
>>>
>>> Signed-off-by: Monish Chunara <monish.chunara@xxxxxxxxxxxxxxxx>
>>> ---
>>>  arch/arm64/boot/dts/qcom/Makefile             |  4 ++
>>>  .../boot/dts/qcom/monaco-evk-sd-card.dtso     | 72 +++++++++++++++++++
>>>  2 files changed, 76 insertions(+)
>>>  create mode 100644 arch/arm64/boot/dts/qcom/monaco-evk-sd-card.dtso
>>>
>>> diff --git a/arch/arm64/boot/dts/qcom/Makefile b/arch/arm64/boot/dts/qcom/Makefile
>>> index 317af937d038..c86242a1631d 100644
>>> --- a/arch/arm64/boot/dts/qcom/Makefile
>>> +++ b/arch/arm64/boot/dts/qcom/Makefile
>>> @@ -46,6 +46,10 @@ lemans-evk-el2-dtbs := lemans-evk.dtb lemans-el2.dtbo
>>>  dtb-$(CONFIG_ARCH_QCOM)	+= lemans-evk-el2.dtb
>>>  dtb-$(CONFIG_ARCH_QCOM)	+= milos-fairphone-fp6.dtb
>>>  dtb-$(CONFIG_ARCH_QCOM)	+= monaco-evk.dtb
>>> +
>>> +monaco-evk-sd-card-dtbs := monaco-evk.dtb monaco-evk-sd-card.dtbo
>>> +dtb-$(CONFIG_ARCH_QCOM) += monaco-evk-sd-card.dtb
>>> +
>>>  dtb-$(CONFIG_ARCH_QCOM)	+= msm8216-samsung-fortuna3g.dtb
>>>  dtb-$(CONFIG_ARCH_QCOM)	+= msm8916-acer-a1-724.dtb
>>>  dtb-$(CONFIG_ARCH_QCOM)	+= msm8916-alcatel-idol347.dtb
>>> diff --git a/arch/arm64/boot/dts/qcom/monaco-evk-sd-card.dtso b/arch/arm64/boot/dts/qcom/monaco-evk-sd-card.dtso
>>> new file mode 100644
>>> index 000000000000..a0bc5c47d40b
>>> --- /dev/null
>>> +++ b/arch/arm64/boot/dts/qcom/monaco-evk-sd-card.dtso
>>> @@ -0,0 +1,72 @@
>>> +// SPDX-License-Identifier: BSD-3-Clause
>>> +/*
>>> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
>>> + */
>>> +
>>> +/dts-v1/;
>>> +/plugin/;
>>> +
>>> +#include <dt-bindings/gpio/gpio.h>
>>> +
>>> +/ {
>>> +        vmmc_sdc: regulator-dummy {
>>
>> No dummy regulators, please.
> 
> ACK, these will be renamed as per the schematic. Since these are direct supplies
> on hardware, used fixed-regulator configuration.
> 
>>
>>> +                compatible = "regulator-fixed";
>>> +
>>> +                regulator-name = "vmmc_sdc";
>>> +                regulator-min-microvolt = <2950000>;
>>> +                regulator-max-microvolt = <2950000>;
>>> +        };
>>> +
>>> +        vreg_sdc: regulator-sdc {
>>> +		compatible = "regulator-gpio";
>>> +
>>> +		regulator-name = "vreg_sdc";
>>> +		regulator-type = "voltage";
>>> +		regulator-min-microvolt = <1800000>;
>>> +		regulator-max-microvolt = <2950000>;
>>> +
>>> +		gpios = <&expander1 7 GPIO_ACTIVE_HIGH>;
>>> +		states = <1800000 1>, <2950000 0>;
>>> +
>>> +		startup-delay-us = <100>;
>>> +        };
>>> +};
>>> +
>>> +&sdhc_1 {
>>> +	vmmc-supply = <&vmmc_sdc>;
>>> +	vqmmc-supply = <&vreg_sdc>;
>>> +
>>> +	pinctrl-0 = <&sdc1_state_on>, <&sd_cd>;
>>> +	pinctrl-1 = <&sdc1_state_off>, <&sd_cd>;
>>> +	pinctrl-names = "default", "sleep";
>>> +
>>> +	cap-sd-highspeed;
>>> +	no-1-8-v;
>>> +
>>> +	bus-width = <4>;
>>> +	cd-gpios = <&tlmm 11 GPIO_ACTIVE_LOW>;
>>> +	no-mmc;
>>> +	no-sdio;
>>> +
>>> +	status = "okay";
>>> +};
>>> +
>>> +&sdhc1_opp_table {
>>
>> Why? Is it specific to the device or to the chip? In the latter case,
>> please define a separate table in the monaco.dtsi and switch to it here.
>>
> 
> As per the previous review, it was suggested to use an existing table. But yes,
> this is specific to the Host controller and the corresponding voltage corners on
> the chip and can be defined as a separate entity for SD card use-case.

The SDC programming guide I have access to does not seem to have bene
updated for any recent chips. Are you sure these different corners are
*actually* valid? The clock-side documentation doesn't mention that

Konrad