From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 893CAC83F1D for ; Thu, 10 Jul 2025 12:56:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:Cc:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=reD0Z/OzeLLuQebkmfVULjQ6q5KpdwV263NNwktOYOs=; b=gAXZ8CN+/ISlJQ3E68bhttPtnh GNmD4wZkSrViqTEBUA9drz1laIP0PGwewWnMD4cik9jk1cJsJ/UU8AO6O0gvlZx85HIQf0943vAVU oXoXIeyHSssk09/KrmLTgxKlkQ4m8kDzHSpLJDxYGmCb18jG69yGEA0o0KmEZY5UQxUDzLOqjwZqa zFJ73kC0kHhD//dALq4mjRwVoc/0OajcdYZTKZF1QidpFV+RBc+J6/eB/Mybe//O3mumYZQElTDUc KJE5CjbuLBzCYuBxWk+8On/OJQVfn9rYa2khJh6BN6JYukpbFxA3BK1JnK6BiS73yaMWusVHE5/c9 SVHFXHqA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uZqod-0000000BqVd-3PXs; Thu, 10 Jul 2025 12:55:55 +0000 Received: from gloria.sntech.de ([185.11.138.130]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uZpio-0000000BfRy-2yWy; Thu, 10 Jul 2025 11:45:51 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Type:Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Reply-To; bh=reD0Z/OzeLLuQebkmfVULjQ6q5KpdwV263NNwktOYOs=; b=Swqb+u8NjwNq2ygF9l+WvV62ey Pkv9pnKzNdO83sVwKtwjQVXeOV6gSh8xMmgNz7fZfu1UJpupxMuQbVMWIYXUtAxjPi/8pAg2sMWbl PHOyY/G+UNhh/+ZUKngi4IC1BpfMnn+7VIttbB0C0UjFVDZzXbn25A/LRkYwvKFf6hDjFMBYgG+9g qkm3alOdWNgnzVVecL+xxKz7QbxfnPhsbidddS3TdgttvQxvr2KlGhsUcV/pVr31IGsOcfrF9DOW+ no8FwUJHfq4Bj/eOSWV+0bCYbd3IOyUPozMYEA04UbE83UlTbsnID5V+mVr0woRc6WqWulZ3AfF+9 cDS5fPSg==; Received: from [194.95.143.137] (helo=phil.localnet) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1uZpih-0004ca-Op; Thu, 10 Jul 2025 13:45:43 +0200 From: Heiko Stuebner To: Chukun Pan Cc: Yao Zi , Rob Herring , Chukun Pan , Jonas Karlman , Conor Dooley , Krzysztof Kozlowski , linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v2 1/1] arm64: dts: rockchip: rk3528: Add CPU frequency scaling support Date: Thu, 10 Jul 2025 13:45:43 +0200 Message-ID: <5025631.aeNJFYEL58@phil> In-Reply-To: <20250620100010.1291658-2-amadeus@jmu.edu.cn> References: <20250620100010.1291658-1-amadeus@jmu.edu.cn> <20250620100010.1291658-2-amadeus@jmu.edu.cn> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250710_044550_749854_ABE1B3F4 X-CRM114-Status: GOOD ( 16.58 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Am Freitag, 20. Juni 2025, 12:00:10 Mitteleurop=C3=A4ische Sommerzeit schri= eb Chukun Pan: > By default, the CPUs on RK3528 operates at 1.5GHz. Add CPU frequency and > voltage mapping to the device tree to enable dynamic scaling via cpufreq. >=20 > The OPP values come from downstream kernel[1]. Both 408MHz and 600MHz > frequencies use the normal PLL, so use the corresponding highest voltage. >=20 > The voltage used for other frequencies can't be less than above (875mV). > Therefore, 816MHz to 1200MHz also uses the corresponding highest voltage. There has often been the argument that selecting a frequency that has the same voltage as a faster frequency does not save any power. Hence I remember that we dropped slower frequencies on other socs that share the same voltage with a higher frequency. >=20 > The remaining 1416MHz to 2016MHz use a voltage close to actual frequency. >=20 > [1] https://github.com/rockchip-linux/kernel/blob/develop-5.10/arch/arm64= /boot/dts/rockchip/rk3528.dtsi >=20 > Signed-off-by: Chukun Pan > --- > arch/arm64/boot/dts/rockchip/rk3528.dtsi | 64 ++++++++++++++++++++++++ > 1 file changed, 64 insertions(+) >=20 > diff --git a/arch/arm64/boot/dts/rockchip/rk3528.dtsi b/arch/arm64/boot/d= ts/rockchip/rk3528.dtsi > index 829f980ea353..5cb7f10b79ed 100644 > --- a/arch/arm64/boot/dts/rockchip/rk3528.dtsi > +++ b/arch/arm64/boot/dts/rockchip/rk3528.dtsi > @@ -53,6 +53,7 @@ cpu0: cpu@0 { > device_type =3D "cpu"; > enable-method =3D "psci"; > clocks =3D <&scmi_clk SCMI_CLK_CPU>; > + operating-points-v2 =3D <&cpu_opp_table>; > }; > =20 > cpu1: cpu@1 { > @@ -61,6 +62,7 @@ cpu1: cpu@1 { > device_type =3D "cpu"; > enable-method =3D "psci"; > clocks =3D <&scmi_clk SCMI_CLK_CPU>; > + operating-points-v2 =3D <&cpu_opp_table>; > }; > =20 > cpu2: cpu@2 { > @@ -69,6 +71,7 @@ cpu2: cpu@2 { > device_type =3D "cpu"; > enable-method =3D "psci"; > clocks =3D <&scmi_clk SCMI_CLK_CPU>; > + operating-points-v2 =3D <&cpu_opp_table>; > }; > =20 > cpu3: cpu@3 { > @@ -77,6 +80,67 @@ cpu3: cpu@3 { > device_type =3D "cpu"; > enable-method =3D "psci"; > clocks =3D <&scmi_clk SCMI_CLK_CPU>; > + operating-points-v2 =3D <&cpu_opp_table>; > + }; > + }; > + > + cpu_opp_table: opp-table-cpu { > + compatible =3D "operating-points-v2"; > + opp-shared; > + > + opp-408000000 { > + opp-hz =3D /bits/ 64 <408000000>; > + opp-microvolt =3D <875000 875000 1100000>; > + clock-latency-ns =3D <40000>; > + opp-suspend; > + }; > + > + opp-600000000 { > + opp-hz =3D /bits/ 64 <600000000>; > + opp-microvolt =3D <875000 875000 1100000>; > + clock-latency-ns =3D <40000>; > + }; > + > + opp-816000000 { > + opp-hz =3D /bits/ 64 <816000000>; > + opp-microvolt =3D <875000 875000 1100000>; > + clock-latency-ns =3D <40000>; > + }; > + > + opp-1008000000 { > + opp-hz =3D /bits/ 64 <1008000000>; > + opp-microvolt =3D <875000 875000 1100000>; > + clock-latency-ns =3D <40000>; > + }; > + > + opp-1200000000 { > + opp-hz =3D /bits/ 64 <1200000000>; > + opp-microvolt =3D <900000 900000 1100000>; > + clock-latency-ns =3D <40000>; > + }; > + > + opp-1416000000 { > + opp-hz =3D /bits/ 64 <1416000000>; > + opp-microvolt =3D <925000 925000 1100000>; > + clock-latency-ns =3D <40000>; > + }; > + > + opp-1608000000 { > + opp-hz =3D /bits/ 64 <1608000000>; > + opp-microvolt =3D <975000 975000 1100000>; > + clock-latency-ns =3D <40000>; > + }; > + > + opp-1800000000 { > + opp-hz =3D /bits/ 64 <1800000000>; > + opp-microvolt =3D <1037500 1037500 1100000>; > + clock-latency-ns =3D <40000>; > + }; > + > + opp-2016000000 { > + opp-hz =3D /bits/ 64 <2016000000>; > + opp-microvolt =3D <1100000 1100000 1100000>; > + clock-latency-ns =3D <40000>; > }; > }; > =20 >=20