From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.manjaro.org (mail.manjaro.org [116.203.91.91]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3E7036995D; Fri, 1 Mar 2024 08:13:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=116.203.91.91 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709280820; cv=none; b=m2aA1r6nWum+lHjuBL4YOPobFhi1gkc+0ZyKvJjDMuOUoZLW1WLixZpQ5xcg6G/+ERp9ycDSWYjswlXP1sauPfSW8AP/xkSCgtSbPupGop2D1VRXFh+l2LfG58DQCs1lxIzmu4GLUQf4ye/vZQLXnyMv/HiObOtuemDfBbilAE8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709280820; c=relaxed/simple; bh=dIBc7HjV1Jitsja9ViMJ47634yFWwSSxGW6Tq58Pth4=; h=MIME-Version:Date:From:To:Cc:Subject:In-Reply-To:References: Message-ID:Content-Type; b=fKJ73IY2QgQAZQTY1idJHX4fqA6JLpfYcwb49WUny+1YjJr0xEc7Lt6sX3KTpq1DlqIX5peFnCzq75qsRNY+YM9EREgxHCc43rCjedWlGhd3KN33r3Q0YOi7BurWj2FOGQad5ldsK9KKoVnfb6LSNwjvsu/vJKcXmo8z+8vONfA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manjaro.org; spf=pass smtp.mailfrom=manjaro.org; dkim=pass (2048-bit key) header.d=manjaro.org header.i=@manjaro.org header.b=hdfnM5bg; arc=none smtp.client-ip=116.203.91.91 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manjaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=manjaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=manjaro.org header.i=@manjaro.org header.b="hdfnM5bg" Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=manjaro.org; s=2021; t=1709280815; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2ERX/sFnvQOPRQmjacsPInt4AlnqdKFHst8ABmqjoTY=; b=hdfnM5bgbjvJIwpYUw2STixSsJuPQE86CfBtC2K6cIeP8wxJnjEaSVtUUk3opxjhCe7SlE K9y2fZ0ISF5aajNWYUQZE7DNgX785YEYnn3VaZVuk5NUdGkzOUJ9YVY9/hlZHyHsIkXJ5z RpS1cniJO4VNCDq4iJ7PkRagCeWPq4cZM2OYbzcoXT5U5/k0tpLbzrRhDIYowphhwRGvQn bOPe+PLoVHPCBO6dEBzVD3Qw2CP1leOYVH+/D0BmOhg9nLiGeOFH5KsL/zCbxPqES4CVP4 7JGiYkqmsc5g9o7WnJHBH0Hy3kuRODL1jgPmBAPbGG4OFeIUsEE4J1inn6bUPw== Date: Fri, 01 Mar 2024 09:13:34 +0100 From: Dragan Simic To: Alexey Charkov Cc: Rob Herring , Krzysztof Kozlowski , Conor Dooley , Heiko Stuebner , Daniel Lezcano , Viresh Kumar , Chen-Yu Tsai , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 3/5] arm64: dts: rockchip: Add CPU/memory regulator coupling for RK3588 In-Reply-To: <20240229-rk-dts-additions-v3-3-6afe8473a631@gmail.com> References: <20240229-rk-dts-additions-v3-0-6afe8473a631@gmail.com> <20240229-rk-dts-additions-v3-3-6afe8473a631@gmail.com> Message-ID: <7e4379931dc6e35ca79a0ec7d27cf590@manjaro.org> X-Sender: dsimic@manjaro.org Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Authentication-Results: ORIGINATING; auth=pass smtp.auth=dsimic@manjaro.org smtp.mailfrom=dsimic@manjaro.org On 2024-02-29 20:26, Alexey Charkov wrote: > RK3588 chips allow for their CPU cores to be powered by a different > supply vs. their corresponding memory interfaces, and two of the > boards currently upstream do that (EVB1 and QuartzPro64). The only reasonable explanation, based on the Cortex-A55 and Cortex-A76 technical reference manuals (TRMs), and some other documents, including the RK3588 hardware design guide (HDG), is that the VDD_CPU_BIG0_MEM_S0, VDD_CPU_BIG1_MEM_S0 and VDD_CPU_LIT_MEM_S0 voltages are internally used as the supplies for the SRAM used for the A76's and A55's L1 and L2 caches, which are both per-core and private in the DynamIQ SoC layout that the RK3588 is based on. Sure, using "MEM" there is confusing, but actually, the Cortex-A55 and Cortex-A76 refer to the L1 and L2 caches as "memory" in multiple places. I'd say that's the reason for "MEM" (and "memory", in the RK3588 HDG) to be used in the board schematics (and in the RK3588 HDG). The RK3588 HDG specifically allows what the Rock 5B does there, i.e. to basically short the RK3588's individual *_MEM_S0 power inputs to the respective CPU core power supplies, which avoids the need to use separate voltage regulators for the RK3588's *_MEM_S0 power inputs. However, I'd really, _really_ love to know why did Rockchip opt to make the power supply voltages separate for the RK3588's L1 and L2 caches, which are, BTW, rated for up to 100 mA for each *_MEM_S0 input, meaning that they present no large loads? All that under the assumption that my analysis is correct, of course. > The voltage of the memory interface though has to match that of the > CPU cores that use it, which downstream kernels achieve by the means > of a custom cpufreq driver which adjusts both at the same time. > > It seems that regulator coupling is a more appropriate generic > interface for it, so this patch introduces coupling to affected > device trees to ensure that memory interface voltage is also updated > whenever cpufreq switches between CPU OPPs. I'll verify this a bit later and provide a separate response. > Note that other boards, such as Radxa Rock 5B, define both the CPU > and memory interface regulators as aliases to the same DT node, so > this doesn't apply there. Yup, they're actually shorted on the Rock 5B, as I described above. > Signed-off-by: Alexey Charkov > --- > arch/arm64/boot/dts/rockchip/rk3588-evb1-v10.dts | 12 ++++++++++++ > arch/arm64/boot/dts/rockchip/rk3588-quartzpro64.dts | 12 ++++++++++++ > 2 files changed, 24 insertions(+) > > diff --git a/arch/arm64/boot/dts/rockchip/rk3588-evb1-v10.dts > b/arch/arm64/boot/dts/rockchip/rk3588-evb1-v10.dts > index de30c2632b8e..dfae67f1e9c7 100644 > --- a/arch/arm64/boot/dts/rockchip/rk3588-evb1-v10.dts > +++ b/arch/arm64/boot/dts/rockchip/rk3588-evb1-v10.dts > @@ -788,6 +788,8 @@ regulators { > vdd_cpu_big1_s0: dcdc-reg1 { > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_big1_mem_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <550000>; > regulator-max-microvolt = <1050000>; > regulator-ramp-delay = <12500>; > @@ -800,6 +802,8 @@ regulator-state-mem { > vdd_cpu_big0_s0: dcdc-reg2 { > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_big0_mem_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <550000>; > regulator-max-microvolt = <1050000>; > regulator-ramp-delay = <12500>; > @@ -812,6 +816,8 @@ regulator-state-mem { > vdd_cpu_lit_s0: dcdc-reg3 { > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_lit_mem_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <550000>; > regulator-max-microvolt = <950000>; > regulator-ramp-delay = <12500>; > @@ -836,6 +842,8 @@ regulator-state-mem { > vdd_cpu_big1_mem_s0: dcdc-reg5 { > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_big1_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <675000>; > regulator-max-microvolt = <1050000>; > regulator-ramp-delay = <12500>; > @@ -849,6 +857,8 @@ regulator-state-mem { > vdd_cpu_big0_mem_s0: dcdc-reg6 { > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_big0_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <675000>; > regulator-max-microvolt = <1050000>; > regulator-ramp-delay = <12500>; > @@ -873,6 +883,8 @@ regulator-state-mem { > vdd_cpu_lit_mem_s0: dcdc-reg8 { > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_lit_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <675000>; > regulator-max-microvolt = <950000>; > regulator-ramp-delay = <12500>; > diff --git a/arch/arm64/boot/dts/rockchip/rk3588-quartzpro64.dts > b/arch/arm64/boot/dts/rockchip/rk3588-quartzpro64.dts > index 87a0abf95f7d..9c038450cd7c 100644 > --- a/arch/arm64/boot/dts/rockchip/rk3588-quartzpro64.dts > +++ b/arch/arm64/boot/dts/rockchip/rk3588-quartzpro64.dts > @@ -818,6 +818,8 @@ vdd_cpu_big1_s0: dcdc-reg1 { > regulator-name = "vdd_cpu_big1_s0"; > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_big1_mem_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <550000>; > regulator-max-microvolt = <1050000>; > regulator-ramp-delay = <12500>; > @@ -831,6 +833,8 @@ vdd_cpu_big0_s0: dcdc-reg2 { > regulator-name = "vdd_cpu_big0_s0"; > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_big0_mem_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <550000>; > regulator-max-microvolt = <1050000>; > regulator-ramp-delay = <12500>; > @@ -844,6 +848,8 @@ vdd_cpu_lit_s0: dcdc-reg3 { > regulator-name = "vdd_cpu_lit_s0"; > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_lit_mem_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <550000>; > regulator-max-microvolt = <950000>; > regulator-ramp-delay = <12500>; > @@ -870,6 +876,8 @@ vdd_cpu_big1_mem_s0: dcdc-reg5 { > regulator-name = "vdd_cpu_big1_mem_s0"; > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_big1_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <675000>; > regulator-max-microvolt = <1050000>; > regulator-ramp-delay = <12500>; > @@ -884,6 +892,8 @@ vdd_cpu_big0_mem_s0: dcdc-reg6 { > regulator-name = "vdd_cpu_big0_mem_s0"; > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_big0_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <675000>; > regulator-max-microvolt = <1050000>; > regulator-ramp-delay = <12500>; > @@ -910,6 +920,8 @@ vdd_cpu_lit_mem_s0: dcdc-reg8 { > regulator-name = "vdd_cpu_lit_mem_s0"; > regulator-always-on; > regulator-boot-on; > + regulator-coupled-with = <&vdd_cpu_lit_s0>; > + regulator-coupled-max-spread = <10000>; > regulator-min-microvolt = <675000>; > regulator-max-microvolt = <950000>; > regulator-ramp-delay = <12500>;