From patchwork Thu Nov 9 19:13:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jim Quinlan X-Patchwork-Id: 13451652 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 BFF95C4332F for ; Thu, 9 Nov 2023 19:14:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234659AbjKITOI (ORCPT ); Thu, 9 Nov 2023 14:14:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230185AbjKITOI (ORCPT ); Thu, 9 Nov 2023 14:14:08 -0500 Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D1FA3C13 for ; Thu, 9 Nov 2023 11:14:06 -0800 (PST) Received: by mail-pl1-x636.google.com with SMTP id d9443c01a7336-1cc58219376so11195345ad.1 for ; Thu, 09 Nov 2023 11:14:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; t=1699557245; x=1700162045; darn=vger.kernel.org; h=references:in-reply-to:message-id:date:subject:cc:to:from:from:to :cc:subject:date:message-id:reply-to; bh=cj3ECyT0kKgX9OMN3LVQVHviwSNFY7MUvWn4Mo5E0xo=; b=d0FJLKJnFN5cfBwkNrhCgVq+sJRGSYr3WbAQHfmFU7gG011wWUA/vuBrb6lsfbaQXA k3IMlXTKARr4HktCzJk7IeVH97V42zhQKLedcZWRMiDwPqbsX6ps+IL/kF+lqA1p7xnc rBNheoUQkkfnAEyTP7JlLrJtBLLLMBtOXDb+Q= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699557245; x=1700162045; h=references:in-reply-to:message-id:date:subject:cc:to:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=cj3ECyT0kKgX9OMN3LVQVHviwSNFY7MUvWn4Mo5E0xo=; b=qKMhL4fv0udk8qAFIXQ8kdaQPAZbq4Fn35VI//uS1mI6bq6TrzF8hS/wu0Crka1hv+ Axm+onsA2O9it9maRT5baA+Pjj4a7v61hb99NqNRFnxb+sM7M73GKT81t5ynrVbq3E62 kXpDDCuRsBcEKs0F1zbWmPdsE4tP0V94HQJ6HhrwYULQKKbltoQoNuv84wsAXtj+3+W3 p4T7POrsXP/8ATWFl+pPgLgZ54skDOmZ+6aoV0w6RX0Z+EnoqVIeI15Cn1btocJ52wWH AxRO0DQIY/MM6ZvE/OdCw2fyT/sWrfT/k8jL3c63P+CGnzwhXsgb/FufYjJYHnND9+8I DOWQ== X-Gm-Message-State: AOJu0Yy2ai9CJH8TB95a0OfOL4s/e5nOOaC8wMV0AkB6BE/OgxaaJpRA OxCQDh3x6ybQXN4ivGMNg1yFSEzVveWAbxeS7gI+P4fEHi9iVUwy+Q8WsjTF2Zf2NDBgfsruEqW eNyFsDXQg4pTurfFrodE44npPjZ8JdUrTMvHQ3dwy8VxK9sC5WAM1Sm3ViQSU/Q8YSBnXtzC3bE RsG1RKPi0H3JPC X-Google-Smtp-Source: AGHT+IEeKu000QUnOY8ufASRQnlK20TPw6yuERVkwYldxGsl22CFd1ano6SoYr6eisX00tuZkdW9tw== X-Received: by 2002:a17:90b:4c91:b0:27f:df1e:199e with SMTP id my17-20020a17090b4c9100b0027fdf1e199emr3039866pjb.28.1699557245028; Thu, 09 Nov 2023 11:14:05 -0800 (PST) Received: from stbsrv-and-01.and.broadcom.net ([192.19.144.250]) by smtp.gmail.com with ESMTPSA id pj9-20020a17090b4f4900b00282ecb631a9sm124069pjb.25.2023.11.09.11.14.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Nov 2023 11:14:04 -0800 (PST) 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 v7 1/3] dt-bindings: PCI: brcmstb: Add property "brcm,clkreq-mode" Date: Thu, 9 Nov 2023 14:13:52 -0500 Message-Id: <20231109191355.27738-2-james.quinlan@broadcom.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20231109191355.27738-1-james.quinlan@broadcom.com> References: <20231109191355.27738-1-james.quinlan@broadcom.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.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 --- .../bindings/pci/brcm,stb-pcie.yaml | 21 +++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml index 7e15aae7d69e..992b35e915a5 100644 --- a/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml +++ b/Documentation/devicetree/bindings/pci/brcm,stb-pcie.yaml @@ -64,6 +64,27 @@ properties: aspm-no-l0s: true + brcm,clkreq-mode: + description: A string that determines the operating + clkreq mode of the PCIe RC HW WRT 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 Tclron max + timing of 400ns as specified in "Dynamic Clock Control", + section 3.2.5.2.2 of the PCIe spec. 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