On Tue, Sep 02, 2025 at 02:56:37PM +0800, Yingying Tang wrote:
>
>
> On 9/2/2025 10:37 AM, Dmitry Baryshkov wrote:
> > 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.
>
> Hi Dimitry,
>
> During the UEFI boot phase, the WLAN enable GPIO has already been asserted, and the WLAN chip is functioning normally.
> If we include this GPIO in the kernel device tree, when the kernel configures this GPIO, its voltage level may experience a brief glitch, which could cause the WLAN chip to reset and result in a PCIe link down.
Here you are describing driver behaviour. It's a software issue and
can be handled in the driver.
I'm asking you to describe the hardware. From the hardware perspective
there is a GPIO pin. Please describe it in the DT.
> So I didn't add wlan-en-gpio in this hamoa's device tree.
>
>
>
> >
> >>
> >> 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
