From patchwork Wed Apr 3 21:38:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jim Quinlan X-Patchwork-Id: 13616736 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 7AB16CD1288 for ; Wed, 3 Apr 2024 21:39:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: MIME-Version:List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe :List-Id:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; 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AJvYcCUkRDkI6eA5OlfWSDy+Ux5VCXrlFuW+ngqVBL00Tz3GAQBKr+L7pZ85zbJeZ08c4RtKHbmf+Ra6TswhPffyHa3zmzTG/S6v+DpXcxRHUe81cx7moEc= X-Gm-Message-State: AOJu0YyM17jEM+T+ASLThZjiEzL8i0q+zHZxfO88RFWv8OLUNLB/3Omk Vsk4sGlet+curGqurpX/ZHbSf+9etzGbMgefTOH0PXOGSZUxxbd+Ee1ftO2yK4lPKuB0l7B3yYo = X-Google-Smtp-Source: AGHT+IGlR1uW9LzpHr+wnIKA1zbBfeqbFshXzeFwm8pcv2wiLPbzzMpB8p5PBY53bhBMCO3KfvaNtA== X-Received: by 2002:a05:6214:258b:b0:699:163c:a44c with SMTP id fq11-20020a056214258b00b00699163ca44cmr706072qvb.1.1712180348684; Wed, 03 Apr 2024 14:39:08 -0700 (PDT) Received: from stbsrv-and-01.and.broadcom.net ([192.19.144.250]) by smtp.gmail.com with ESMTPSA id pi10-20020a0562144a8a00b0069903cddc96sm1750739qvb.18.2024.04.03.14.39.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Apr 2024 14:39:07 -0700 (PDT) From: Jim Quinlan To: linux-pci@vger.kernel.org, Nicolas Saenz Julienne , Bjorn Helgaas , Lorenzo Pieralisi , Cyril Brulebois , Phil Elwell , bcm-kernel-feedback-list@broadcom.com, james.quinlan@broadcom.com Cc: Jim Quinlan , Florian Fainelli , Lorenzo Pieralisi , =?utf-8?q?Krzysztof_Wilczy=C5=84?= =?utf-8?q?ski?= , Rob Herring , Krzysztof Kozlowski , Conor Dooley , linux-arm-kernel@lists.infradead.org (moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE), linux-rpi-kernel@lists.infradead.org (moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE), devicetree@vger.kernel.org (open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v9 1/4] dt-bindings: PCI: brcmstb: Add property "brcm,clkreq-mode" Date: Wed, 3 Apr 2024 17:38:58 -0400 Message-Id: <20240403213902.26391-2-james.quinlan@broadcom.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20240403213902.26391-1-james.quinlan@broadcom.com> References: <20240403213902.26391-1-james.quinlan@broadcom.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240403_143910_305841_346BFB57 X-CRM114-Status: GOOD ( 11.86 ) 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: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The Broadcom STB/CM PCIe HW -- a core that is also used by RPi SOCs -- requires the driver to deliberately place the RC HW one of three CLKREQ# modes. The "brcm,clkreq-mode" property allows the user to override the default setting. If this property is omitted, the default mode shall be "default". Signed-off-by: Jim Quinlan Acked-by: Conor Dooley Reviewed-by: Rob Herring --- .../devicetree/bindings/pci/brcm,stb-pcie.yaml | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml index 7e15aae7d69e..22491f7f8852 100644 --- a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml +++ b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml @@ -64,6 +64,24 @@ properties: aspm-no-l0s: true + brcm,clkreq-mode: + description: A string that determines the operating + clkreq mode of the PCIe RC HW with respect to controlling the refclk + signal. There are three different modes -- "safe", which drives the + refclk signal unconditionally and will work for all devices but does + not provide any power savings; "no-l1ss" -- which provides Clock + Power Management, L0s, and L1, but cannot provide L1 substate (L1SS) + power savings. If the downstream device connected to the RC is L1SS + capable AND the OS enables L1SS, all PCIe traffic may abruptly halt, + potentially hanging the system; "default" -- which provides L0s, L1, + and L1SS, but not compliant to provide Clock Power Management; + specifically, may not be able to meet the T_CLRon max timing of 400ns + as specified in "Dynamic Clock Control", section 3.2.5.2.2 PCI + Express Mini CEM 2.1 specification. This situation is atypical and + should happen only with older devices. + $ref: /schemas/types.yaml#/definitions/string + enum: [ safe, no-l1ss, default ] + brcm,scb-sizes: description: u64 giving the 64bit PCIe memory viewport size of a memory controller. There may be up to