From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6550438657B; Wed, 4 Mar 2026 08:08:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772611727; cv=none; b=m1qBwq3/e0zRJCHoj9jutuXZmjy2d1qbsTV3MaciavcozSF2hYRvZ0lNtqW+celCTKuetwlS38DXd920gzI49zyNjqQH0PGJjOIuwlmflGRSqpNYvSI+MP+0/fuTPi1aC5kmY11h231cM7GpnAOktUTFnYDvOu3+Qas7bs6tthA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772611727; c=relaxed/simple; bh=Q9eQAaHfbimh/OgPN9DKz1Eoxd8bQF170nC43iXD4Ak=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=mS2yB8tG3+U0Is90QmPSyd7IfYDc2GTgQOo3WZF/VoUIvREbOc8lxOxM/PkbXk9g9ZNXlRlF7xGh3h25jKVZuTO6hxyJycgQyEgXKjnTHygUSLtdBKWsT2YG1hNADwnAnKciy/U60JjbNbQtR82dyd9SL8WpJe754kZSZAqimQI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=D4lx/WGZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="D4lx/WGZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD3D2C2BCAF; Wed, 4 Mar 2026 08:08:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772611726; bh=Q9eQAaHfbimh/OgPN9DKz1Eoxd8bQF170nC43iXD4Ak=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=D4lx/WGZ+r/QOXj+VJ6sJUeR1KIBHkZnCFhx6OdffahLfLmGGMlFQUOk/xKaOKpKo Hrv11Dwz5dqeYQqvWJk+0rSxKSPj2B8ClLCxrvhi48vTNABTBw0iBDuwDsIR5Cfd1l EywjgJTI1FYC4G6EVySgR4N5jZrcKER8JRnaHgSDakQilL3lV8XLPGlSi8CsUnLtl4 oRLswbtkPp/zEyW0f7q6aaE46waqONt/Klo0WxFCKLPr2YwDIQ4VSslpsteenjj0Tt xdtuPE+iPcX2ZUmaEjAyaXnJL7r8HjWLN92Joo8JRCEYSTPuwbyXQ5T9VrSZDoerjZ xix3ylhpOkA3Q== Message-ID: <06f7ad53-c650-4498-be3b-5ef5719c3d8b@kernel.org> Date: Wed, 4 Mar 2026 09:08:41 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/3] arm64: dts: exynos: ExynosAutov920: Add regulators for the USB To: pritam.sutar@samsung.com, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, alim.akhtar@samsung.com Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, rosa.pila@samsung.com, dev.tailor@samsung.com, faraz.ata@samsung.com, muhammed.ali@samsung.com, selvarasu.g@samsung.com References: <20260122130721.205664-1-pritam.sutar@samsung.com> <20260122130721.205664-3-pritam.sutar@samsung.com> <352427f4-144a-4a43-a2f3-dd959302939f@kernel.org> <000001dc9c13$ea305520$be90ff60$@samsung.com> <2edff611-76bb-45aa-922e-f96581dd0525@kernel.org> <019001dca0b8$f709e640$e51db2c0$@samsung.com> <000001dcabab$089a75d0$19cf6170$@samsung.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 8bit On 04/03/2026 08:46, pritam.sutar@samsung.com wrote: > Hi Krzysztof, > >> -----Original Message----- >> From: Krzysztof Kozlowski >> Sent: Thursday, February 19, 2026 1:24 AM >> To: pritam.sutar@samsung.com; robh@kernel.org; krzk+dt@kernel.org; >> conor+dt@kernel.org; alim.akhtar@samsung.com >> Cc: devicetree@vger.kernel.org; linux-arm-kernel@lists.infradead.org; linux- >> samsung-soc@vger.kernel.org; linux-kernel@vger.kernel.org; >> rosa.pila@samsung.com; dev.tailor@samsung.com; >> faraz.ata@samsung.com; muhammed.ali@samsung.com; >> selvarasu.g@samsung.com >> Subject: Re: [PATCH v2 2/3] arm64: dts: exynos: ExynosAutov920: Add >> regulators for the USB >> >> On 18/02/2026 10:28, pritam.sutar@samsung.com wrote: >>>>>>> + usbdrd31_dwc3_vbus: usbdrd31_dwc3-vbus { >>>>>> >>>>>> Please use name for all fixed regulators which matches current >>>>>> format >>>>>> recommendation: 'regulator-[0-9]v[0-9]' >>>>>> >>>>>> https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux. >>>>>> gi >>>>>> t/tree/ >>>>>> Documentation/devicetree/bindings/regulator/fixed-regulator.yaml >>>>>> >>>>>> None of the regulators are called like you wrote. Really NONE. >>>>>> >>>>> >>>>> Thank you for the references. Will bring changes for regulator's >>>>> name and labels as >>>>> >>>>> - usbdrd31_dwc3_vbus: usbdrd31_dwc3-vbus { >>>>> + reg_usbdrd31_dwc3_vbus: regulator-1 { >>>> >>>> Did you read the binding? That's not what I asked. >>>> >>> >>> Yes. >>> Sorry for misinterpreting above comment. Is it expected as below? >>> >>> This is based on our understanding by referring binding and other vendor >> dts. >>> >>> --- a/arch/arm64/boot/dts/exynos/exynosautov920-sadk.dts >>> +++ b/arch/arm64/boot/dts/exynos/exynosautov920-sadk.dts >>> @@ -59,7 +59,7 @@ dummy_regulator: regulator-0 { >>> regulator-name = "dummy_regulator"; >>> }; >>> >>> - usbdrd31_dwc3_vbus: usbdrd31_dwc3-vbus { >>> + reg_usb_vbus0: regulator-5v0-vbus0 { >> >> Yes, that's better. > > Thank you for the confirmation. > >> >> Only under the assumption these are actually dedicated single-enable-pin >> regulators, not pins going to the PMIC. >> > > Yes. this is dedicated single-enable-pin. > >>> compatible = "regulator-fixed"; >>> regulator-name = "usbdrd31_dwc3-vbus"; >>> regulator-min-microvolt = <5000000>; @@ -75,7 +75,7 @@ >>> usb_phy0: usb-phy0 { >>> vbus-supply = <&usbdrd31_dwc3_vbus>; >>> }; >>> >> >> ... >> >>>>>> >>>>>> That's a bit too much of dummies. This is heavily incomplete. You >>>>>> need to bring back the PMIC first. >>>>>> >>>>> >>>>> Presently, relying on USB LDOs being enabled by the bootloader in >>>>> this automotive SoC. However, we understand the concern and it is >>>>> added in case if anyone wants to use implemented PMIC in future. For >>>>> now, would like to proceed with the dummy regulators to enable the >>>>> required USB >>>> features. >>>> >>>> And I don't see the point of these dummies. Solves nothing. >>>> >>> >>> Are you expecting details as mentioned in above section in commit >> message? >>> However, we have mentioned these details in cover letter. >> >> No, I am expecting proper PMIC to be represented here. One dummy >> regulator during the fast development phase is okay. Dummy added by >> community contributors without resources and schematics would also fly. >> >> But Samsung, with all the resources, schematics doing development since >> 2023 and still adding 20 dummies to every device? Nope, no, sorry. >> >> Please start doing this properly. Look how entire new SoC was upstreamed >> by Linaro: >> https://lore.kernel.org/all/20231121-topic-sm8650-upstream-dt-v3-0- >> db9d0507ffd3@linaro.org/ >> >> Or something newer by Qualcomm: >> https://lore.kernel.org/linux-arm-msm/?q=s%3Aglymur >> > > Appreciated for the references. > > As you might know, the regulator control and power‑management architecture > has changed in recent Exynos SoCs. It is now controlled by the ACPM/APM core, and > the PMIC is interfaced over SPMI (instead of the legacy I2C interface). I am checking > internally how to implement this, and it may take a bit longer to have the full recipe > ready to add an actual regulator. I did not say anything odd about the process. You should have done ACPM/APM/SPMI much earlier, because PMIC is a necessary early step in upstreaming. Your explanation feels like you are surprised. > > USB is one of the critical IP blocks that needs be enabled to allow the rest of the > team’s workflow over USB (e.g., enabling automation via USB for testing, etc.). PMIC is before USB... > > If these changes can be accommodated, it would be great. In the meantime, > I will continue working internally to see how we can push the missing pieces upstream. Sorry, I am not taking ~22 phandles to a dummy regulator. Best regards, Krzysztof