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 924ACC4828F for ; Wed, 7 Feb 2024 07:19:57 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=6SYbxDYeGniiA6rdtb6/T8QgKPCQ4hLYc/Upt3Qn8Ng=; b=drH3H3wbsd8myPJAlIxLLxPjRp OSdsm/oVz3PaFuHkhGkRX+0ZoKNrSzP4JdrPFKJV0O96ZYZwvW2FvHYz1JMnUKe2xSjYC/9ndYJjI ug62xa6ab5RUtGnBVMqOOeHmUCvPM7P3jciUoEfcVEvODy8fpz0itsq73gSDysgAx1KnnTyqzQ6Ul BDve1jl8P0lTE5HSe/Zawg1+y365bkfZjS3TFth0B8SB0VeNO0nPfdq+pFEkaBjyALo8R0BwwLSmd HyXnyEHOlNOqANgYGiYwMRTRNPPNZN+LL2D1okwO6hx3M5zCzzk3n9sta4uMlESSoAIPs3tcVWKFF 1lF+5NTQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rXcDt-00000009v6Z-13zA; Wed, 07 Feb 2024 07:19:57 +0000 Received: from mail-ed1-x535.google.com ([2a00:1450:4864:20::535]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rXcDq-00000009v5p-20bm for linux-mediatek@lists.infradead.org; Wed, 07 Feb 2024 07:19:55 +0000 Received: by mail-ed1-x535.google.com with SMTP id 4fb4d7f45d1cf-55a5e7fa471so292269a12.1 for ; Tue, 06 Feb 2024 23:19:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1707290392; x=1707895192; darn=lists.infradead.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=6SYbxDYeGniiA6rdtb6/T8QgKPCQ4hLYc/Upt3Qn8Ng=; b=hRJX/V6VqB7IDSC8Ph4qD+67HouwgMMc3ViJJbcHPNqMI5Bp6jeFEP27eEapggxJwO 8hJHvH+dZo8n8SdcgAv2Y/OI3cTqhqnsmjVwGqvXX82i1E5czo1MaBQkpHpuHBvny2vD QW9znRi+w5XyJX8fT9dfzL2Kcyoz7MbqGBobrVSvd/aqVqzWRa3ISUFHyZqP3+Fk2WYN lg6aFJRV5sQIGBogsv8y558lwKrWnl50b1knOE+xcMLonn0jIg46rVV75EwAGvPGiFNv CFkbR3qqMCThj5dWvcufiuDeBBpgPt5viRG+2PJVn4tR/RklgwCK+ajPhtWifYjs9y2i FNQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1707290392; x=1707895192; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=6SYbxDYeGniiA6rdtb6/T8QgKPCQ4hLYc/Upt3Qn8Ng=; b=ibpkoEDyLVry5AsGU9yWpFO6ym7hG9e4QDZBSi8GvmxrtU6tQHdFMjFezrCAliLd5h pf/i65wsas/YzZGVEDo6Y4y/KvVXjOJNZYr5njSQbws+CNnm7hDsDQ96XpgmIJj4Re5v eLdeG3LwRUecdACJDFggOBpHrf3OSfCNBDdo+2rprCe45odIgaLEdXuXJzD7iHJCBZYK OFk/dz2eHj7ilElYMewbXB7zMx76nFKUhU9jprRtdKV1ChOfs/MzzS5opC79SXAZs1EL SOG8u59QVD8MQ0/Er/Rou7eZeeKeFabwE6lBiaeSuqPEcHzv9ayZB1vA3erTvQfA020h VgzQ== X-Gm-Message-State: AOJu0Yxl6sDhB7CZgE2nxr2SNY65O8/qQ30aur3mHLFrwupj9A5k1mTQ YPuSs5mMX5MphDTITfM+WT1aOSrT+TREWSt/jX667E2HhYDNet+PVKv+GoOpfbM+vKbanivNmka C X-Google-Smtp-Source: AGHT+IGdBxPyBXyrnHPSHM2F9u/oCyDhNJlzKgFj2xDI/+5OYO2QdgsC1LNX75LwkVn1O3UVPPnVZA== X-Received: by 2002:a05:6402:1a44:b0:560:9906:9f31 with SMTP id bf4-20020a0564021a4400b0056099069f31mr3161100edb.27.1707290391944; Tue, 06 Feb 2024 23:19:51 -0800 (PST) X-Forwarded-Encrypted: i=1; AJvYcCW/zdcZSDg4pLH1Rt+RivOPBAEybdDR4XOBF+p0P2MTVI+ITlPExLJz6aP2vR4wY4bD0Kr+LBEn+X5BkmRuCuTKzXHWhd941xh3jYX+JLHAmV90kAmRWUNMWj7iAsSe3JC1WYIqzyWYWKQrXTB9jvgYxIqDpdZZ5qy2GY7FGWOmzZbxXa+X1C2vPCdty640ZQP9B5GftyhfDvl0ro9jYeX42sxJzEacqqg92RmcQr9cXMsmvmALrDL9j5jA74sKkW+MF+y8Qq3lkNA2Gj7ddYm7QHlyjW0K0K78DB0qzPcRH9M5TXELrwvgmM42/kjlCJARJnvdlTeqzwKZt9AaGZmUGeLZ/FGYZIFegYpoam2Y4PjsNOfFR+pwxKTtLGwpyji8GUUKrL4= Received: from linaro.org ([62.231.97.49]) by smtp.gmail.com with ESMTPSA id f1-20020aa7d841000000b00560cd4f3098sm360696eds.95.2024.02.06.23.19.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Feb 2024 23:19:51 -0800 (PST) Date: Wed, 7 Feb 2024 09:19:50 +0200 From: Abel Vesa To: Dmitry Baryshkov Cc: Stephen Boyd , Matthias Brugger , Bjorn Andersson , Konrad Dybcio , AngeloGioacchino Del Regno , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-mediatek@lists.infradead.org Subject: Re: [PATCH RFC 1/2] spmi: Add support for multi-master Message-ID: References: <20240207-spmi-multi-master-support-v1-0-ce57f301c7fd@linaro.org> <20240207-spmi-multi-master-support-v1-1-ce57f301c7fd@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240206_231954_554533_192706EA X-CRM114-Status: GOOD ( 20.79 ) X-BeenThere: linux-mediatek@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-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On 24-02-07 01:55:39, Dmitry Baryshkov wrote: > On Wed, 7 Feb 2024 at 01:34, Abel Vesa wrote: > > > > Some newer SPMI controllers support multiple bus masters. > > Such a master can control multiple slave devices. The generic > > framework needs to be able to pass on the master id to the > > controller-specific driver. So do that. The framework will > > check if the devicetree child nodes are actually bus masters > > and will register the devices for each master. The legacy > > approach will still be supported for backwards compatibility. > > Please remind me, are those two actual bus musters driving a single > bus in parallel or two SPMI buses being handled by a single device? In > the latter case this implementation is incorrect. There should be > multiple spmi_controller instances, one for each bus. Allocate them in > a loop and set ctrl->dev.of_node after allocating. It's two SPMI buses (two sets of wires) handled by the same controller, HW-wise. If we register two spmi controllers with the kernel framework, it will be HW inaccurate, because there is just one controller which has multiple masters. I'm not saying it might not work. But, to me, it looks more like a hack. Basically, we would be mapping HW bus masters to kernel controllers. > > > > > Signed-off-by: Abel Vesa > > --- > > drivers/spmi/spmi-mtk-pmif.c | 6 ++-- > > drivers/spmi/spmi-pmic-arb.c | 10 +++--- > > drivers/spmi/spmi.c | 76 ++++++++++++++++++++++++++++++-------------- > > include/linux/spmi.h | 10 +++--- > > 4 files changed, 67 insertions(+), 35 deletions(-) > > -- > With best wishes > Dmitry