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

[Monish Chunara]

On Mon, Mar 23, 2026 at 03:15:09PM +0100, Konrad Dybcio wrote:
> 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
> 

There seems a gap in the clock documentation. This is being communicated to the
corresponding stakeholders. However, the corners mentioned are as per the
reference platform and will be updated in the subsequent series based on the
updates from the clock-plan PoC as required.

Regards,
Monish