Re: [PATCH v8 3/3] arm64: dts: qcom: Add base HAMOA-IOT-EVK board

[Dmitry Baryshkov]

On Mon, Sep 01, 2025 at 11:02:24AM +0800, Yingying Tang wrote:
> 
> 
> On 8/28/2025 7:18 PM, Dmitry Baryshkov wrote:
> > On Thu, Aug 28, 2025 at 12:48:47PM +0800, Yijie Yang wrote:
> >> The HAMOA-IOT-EVK is an evaluation platform for IoT products, composed of
> >> the Hamoa IoT SoM and a carrier board. Together, they form a complete
> >> embedded system capable of booting to UART.
> >>
> >> This change enables the following peripherals on the carrier board:
> >> - UART
> >> - On-board regulators
> >> - USB Type-C mux
> >> - Pinctrl
> >> - Embedded USB (EUSB) repeaters
> >> - NVMe
> >> - pmic-glink
> >> - USB DisplayPorts
> >> - Bluetooth
> >> - Graphic
> >> - Audio
> >>
> >> Written in collaboration with Quill Qi (Audio) <le.qi@xxxxxxxxxxxxxxxx>,
> >> Jie Zhang (Graphics) <quic_jiezh@xxxxxxxxxxx>, Shuai Zhang (Bluetooth)
> >> <quic_shuaz@xxxxxxxxxxx>, and Yongxing Mou (USB DisplayPorts)
> >> <quic_yongmou@xxxxxxxxxxx>.
> >>
> >> Signed-off-by: Yijie Yang <yijie.yang@xxxxxxxxxxxxxxxx>
> >> ---
> >>  arch/arm64/boot/dts/qcom/Makefile          |    1 +
> >>  arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts | 1247 ++++++++++++++++++++++++++++
> >>  2 files changed, 1248 insertions(+)
> >>
> >> +
> >> +	wcd938x: audio-codec {
> >> +		compatible = "qcom,wcd9385-codec";
> >> +
> >> +		pinctrl-0 = <&wcd_default>;
> >> +		pinctrl-names = "default";
> >> +
> >> +		reset-gpios = <&tlmm 191 GPIO_ACTIVE_LOW>;
> >> +
> >> +		qcom,micbias1-microvolt = <1800000>;
> >> +		qcom,micbias2-microvolt = <1800000>;
> >> +		qcom,micbias3-microvolt = <1800000>;
> >> +		qcom,micbias4-microvolt = <1800000>;
> >> +		qcom,mbhc-buttons-vthreshold-microvolt = <75000 150000 237000 500000
> >> +		500000 500000 500000 500000>;
> > 
> > Other platforms use a single line here. If you don't want to do it,
> > align data to start from the same column rather than restarting from the
> > column 1.
> > 
> >> +		qcom,mbhc-headset-vthreshold-microvolt = <1700000>;
> >> +		qcom,mbhc-headphone-vthreshold-microvolt = <50000>;
> >> +		qcom,rx-device = <&wcd_rx>;
> >> +		qcom,tx-device = <&wcd_tx>;
> >> +
> >> +		vdd-buck-supply = <&vreg_l15b_1p8>;
> >> +		vdd-rxtx-supply = <&vreg_l15b_1p8>;
> >> +		vdd-io-supply = <&vreg_l15b_1p8>;
> >> +		vdd-mic-bias-supply = <&vreg_bob1>;
> >> +
> >> +		#sound-dai-cells = <1>;
> >> +	};
> >> +
> >> +	wcn7850-pmu {
> >> +		compatible = "qcom,wcn7850-pmu";
> >> +
> >> +		vdd-supply = <&vreg_wcn_0p95>;
> >> +		vddio-supply = <&vreg_l15b_1p8>;
> >> +		vddaon-supply = <&vreg_wcn_0p95>;
> >> +		vdddig-supply = <&vreg_wcn_0p95>;
> >> +		vddrfa1p2-supply = <&vreg_wcn_1p9>;
> >> +		vddrfa1p8-supply = <&vreg_wcn_1p9>;
> >> +
> >> +		bt-enable-gpios = <&tlmm 116 GPIO_ACTIVE_HIGH>;
> > 
> > Okay, so how is WiFi controlled? Is there a GPIO? The DT should be
> > describing the hardware, not the UEFI behaviour.
> > 
> Hi Dmitry, as I described in previous mail, On hamoa platfrom whole wifi module's power supply and enable gpio are voted in UEFI.
> Hamoa is PC platform, so BIOS/UEFI behavior is compatible with Windows/ACPI architecture. UEFI is responsible for enabling power supply 
> for all devices which may be used in boot phase (such as WLAN may be used to boot from network).

This is not completely relevant. You are describing driver / Linux /
bootloader behaviour. I asked if there is a GPIO in the hardware. If
there is one, please add it here.

> 
> So we need not Wifi chip's power and control GPIO in kernel side, thanks 

What if someone requests this GPIO from userspace and pulls it down?

> >> +
> >> +		pinctrl-0 = <&wcn_bt_en>;
> >> +		pinctrl-names = "default";
> >> +
> > 
> 

-- 
With best wishes
Dmitry