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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6FD95C4332F for ; Mon, 13 Nov 2023 15:27:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231200AbjKMP1U (ORCPT ); Mon, 13 Nov 2023 10:27:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229612AbjKMP1T (ORCPT ); Mon, 13 Nov 2023 10:27:19 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0096D67 for ; Mon, 13 Nov 2023 07:27:16 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35813C433C8; Mon, 13 Nov 2023 15:27:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699889236; bh=DRPBcEhQyl5dBAyB3ocbVXLLrdNG2CNj1hnyQAWHnHg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mYHatumpK1ANV48WUwMjoE3E52AEZimGacsM7qM5CtMdYWnLpO64MElZyeVRny1Ts dgte0Jjd2mztihTSm7cR8QfDZClb0X/qCPxHlGx8l3qCqJGb0a0EYvCyNC46vAPK9x 1bvAJw7FdItWQ7rhdRpJw6TmVJ0DQdNiwBAbIj+Dx86gLuAdO4/nYT94nPU+qK1gpi n6PZ1irGbhIuqIYwnsM5WPYnw/PY2zCDBKputfvI+H/z1XzN9Bf/J54GAV/EivZpJj tEdCeYgBKvcIJ2ldwk9VjM56jhan8eGRy194Bh1yFTyWepLP1oTxBHwhfIsMg3h/iT ukM7SpElUSf5A== Date: Mon, 13 Nov 2023 23:14:55 +0800 From: Jisheng Zhang To: Yixun Lan Cc: Philipp Zabel , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Paul Walmsley , Palmer Dabbelt , Albert Ou , Chao Wei , Chen Wang , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH 3/4] riscv: dts: sophgo: add reset dt node for cv1800b Message-ID: References: <20231113005503.2423-1-jszhang@kernel.org> <20231113005503.2423-4-jszhang@kernel.org> <20231113143224.GA130254@ofsar> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20231113143224.GA130254@ofsar> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 13, 2023 at 02:32:24PM +0000, Yixun Lan wrote: > Hi Jisheng: Hi > > On 08:55 Mon 13 Nov , Jisheng Zhang wrote: > > Add the reset device tree node to cv1800b SoC. > > > > Signed-off-by: Jisheng Zhang > > --- > > arch/riscv/boot/dts/sophgo/cv1800b.dtsi | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi b/arch/riscv/boot/dts/sophgo/cv1800b.dtsi > > index df40e87ee063..4032419486be 100644 > > --- a/arch/riscv/boot/dts/sophgo/cv1800b.dtsi > > +++ b/arch/riscv/boot/dts/sophgo/cv1800b.dtsi > > @@ -54,6 +54,12 @@ soc { > > dma-noncoherent; > > ranges; > > > > + rst: reset-controller@3003000 { > > + compatible = "sophgo,cv1800b-reset"; > > + reg = <0x03003000 0x1000>; > ~~~~~~~ > it should be 0x28 The reg space is 4KB, but only 0x28 are used. I think 0x1000 or 0x28 are fine since the ioremap granule is 4kB. > > while please also note the 0x24 == SOFT_CPUAC_RSTN, does not compatible > with the reset-simple driver, but as it's not implemented nor used in this driver, But the functionality of this "autoclear" reg isn't used at all since we also have "sticky" reset to acchieve the same feature, I.E reset cpusys. And in the usage case of reseting cpusys, I believe "sticky" reset is preferred. And except the cpusys reset which has both autoclear and sticky, other resets are sticky only. I'm not sure whether it's worth to write a new driver for almost useless feature. > so we should be fine with this? > > > + #reset-cells = <1>; > > + }; > > + > > uart0: serial@4140000 { > > compatible = "snps,dw-apb-uart"; > > reg = <0x04140000 0x100>; > > -- > > 2.42.0 > > > > -- > Yixun Lan (dlan) > Gentoo Linux Developer > GPG Key ID AABEFD55