From patchwork Thu Jan 4 13:01:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bartosz Golaszewski X-Patchwork-Id: 13511061 Received: from mail-wr1-f42.google.com (mail-wr1-f42.google.com [209.85.221.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 35493224DA for ; Thu, 4 Jan 2024 13:02:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=bgdev.pl Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bgdev.pl Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bgdev-pl.20230601.gappssmtp.com header.i=@bgdev-pl.20230601.gappssmtp.com header.b="WK1xaleo" Received: by mail-wr1-f42.google.com with SMTP id ffacd0b85a97d-336dcebcdb9so419702f8f.1 for ; Thu, 04 Jan 2024 05:02:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bgdev-pl.20230601.gappssmtp.com; s=20230601; t=1704373322; x=1704978122; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=opVDF4AOHQah3OrT16oGMK2ccRRJHeIMJXkpc+aZwFs=; b=WK1xaleoMk7IVXPllfXEUF4Xo7mTNqo5t2Eu1pESyW/Y+enVzlgw2jNS6NG0ix03uW R3eEPFGjgzWgVBUx6oChjpFfyhCOFLNySVeIg9x/1AyeyCOnHphPJBYjCU11dCsbNd67 jD4Hsp6G8K54zNh+9zAbbMQJODkn84rl4B92p9Efk6QQ1cboEVYDHPFVdBH2wLBTzHyc o33J/zut+6c66m+g+0Qjkogk7AG+SVphmFVCUlA04TUnXWHsucHF8yBrWPh9MbphLmYk Xjo7Y2Xsk+yhKozFeEUyIquoRJwCHZylOWw21UfOv/pobf7YH8XTUf/8rvEGFVGuVWCy ABaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704373322; x=1704978122; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=opVDF4AOHQah3OrT16oGMK2ccRRJHeIMJXkpc+aZwFs=; b=cu/q2e14OUm9Qbjy/g9p3g3VOKjVzsGorZVQZrVkzek4FJwl6PxcboSCmcUOEoNFHo tXUdMFr8rRdmaUHmsWtNg9L1TVSDUYiOquoZtuGgQVFnVc1F6m3NNfyXVm5Q0jPd62h/ X5yUCZCd4Iqb9unCjPZtyx6TlGqsLhsfjx5L2ctrRxisMG4ZFBuWgJ+hb2bYbEeIg3Hf SgnkajTZ3OrB5Psw3dUf5AzCYqewomizZ8iLRG2Tk4eQwG1pLT3tLyh/M9HFVN2V29Rx b7EKMpDioEFh47Fb1JGlIWKDyH2UkkIhdjYvy6svjM8XdCgbU910RZwS6JHveCuvsaiy mh2g== X-Gm-Message-State: AOJu0YyXwF3zTjBwL7vAvEqtvmgM6wnMvtVVB6Mpghu6GgEHtCTcZ5Ab 8zUqDyuwmIMPvrKw+O2uh1PiSmMa74GNNQ== X-Google-Smtp-Source: AGHT+IFsoUaWFe3hNCg6/b09WcRv7wsIMJMlEiNm/lu4Y1OTN1yICGktvfbzMdrteuCPKZTBntbM6g== X-Received: by 2002:adf:cc86:0:b0:337:157:2d3e with SMTP id p6-20020adfcc86000000b0033701572d3emr161961wrj.222.1704373322145; Thu, 04 Jan 2024 05:02:02 -0800 (PST) Received: from brgl-uxlite.home ([2a01:cb1d:334:ac00:5b69:3768:8459:8fee]) by smtp.gmail.com with ESMTPSA id w5-20020a5d5445000000b0033660f75d08sm32887387wrv.116.2024.01.04.05.02.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 Jan 2024 05:02:01 -0800 (PST) From: Bartosz Golaszewski To: Kalle Valo , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Bjorn Andersson , Konrad Dybcio , Catalin Marinas , Will Deacon , Bjorn Helgaas , Heiko Stuebner , Jernej Skrabec , Chris Morgan , Linus Walleij , Geert Uytterhoeven , Arnd Bergmann , Neil Armstrong , =?utf-8?q?N=C3=ADcolas_F_=2E_R_?= =?utf-8?q?=2E_A_=2E_Prado?= , Marek Szyprowski , Peng Fan , Robert Richter , Dan Williams , Jonathan Cameron , Terry Bowman , Kuppuswamy Sathyanarayanan , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , Huacai Chen , Alex Elder , Srini Kandagatla , Greg Kroah-Hartman Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pci@vger.kernel.org, Bartosz Golaszewski Subject: [RFC 0/9] PCI: introduce the concept of power sequencing of PCIe devices Date: Thu, 4 Jan 2024 14:01:14 +0100 Message-Id: <20240104130123.37115-1-brgl@bgdev.pl> X-Mailer: git-send-email 2.40.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-State: RFC From: Bartosz Golaszewski During last year's Linux Plumbers we had several discussions centered around the need to power-on PCI devices before they can be detected on the bus. The consensus during the conference was that we need to introduce a class of "PCI slot drivers" that would handle the power-sequencing. After some additional brain-storming with Manivannan and the realization that the DT maintainers won't like adding any "fake" nodes not representing actual devices, we decided to reuse the existing infrastructure provided by the PCIe port drivers. The general idea is to instantiate platform devices for child nodes of the PCIe port DT node. For those nodes for which a power-sequencing driver exists, we bind it and let it probe. The driver then triggers a rescan of the PCI bus with the aim of detecting the now powered-on device. The device will consume the same DT node as the platform, power-sequencing device. We use device links to make the latter become the parent of the former. The main advantage of this approach is not modifying the existing DT in any way and especially not adding any "fake" platform devices. Bartosz Golaszewski (9): arm64: dts: qcom: sm8250: describe the PCIe port arm64: dts: qcom: qrb5165-rb5: describe the WLAN module of QCA6390 PCI/portdrv: create platform devices for child OF nodes PCI: hold the rescan mutex when scanning for the first time PCI/pwrseq: add pwrseq core code dt-bindings: vendor-prefixes: add a PCI prefix for Qualcomm Atheros dt-bindings: wireless: ath11k: describe QCA6390 PCI/pwrseq: add a pwrseq driver for QCA6390 arm64: defconfig: enable the PCIe power sequencing for QCA6390 .../net/wireless/qcom,ath11k-pci.yaml | 14 ++ .../devicetree/bindings/vendor-prefixes.yaml | 1 + arch/arm64/boot/dts/qcom/qrb5165-rb5.dts | 24 +++ arch/arm64/boot/dts/qcom/sm8250.dtsi | 10 + arch/arm64/configs/defconfig | 2 + drivers/pci/pcie/Kconfig | 2 + drivers/pci/pcie/Makefile | 2 + drivers/pci/pcie/portdrv.c | 3 +- drivers/pci/pcie/pwrseq/Kconfig | 19 ++ drivers/pci/pcie/pwrseq/Makefile | 4 + drivers/pci/pcie/pwrseq/pcie-pwrseq-qca6390.c | 197 ++++++++++++++++++ drivers/pci/pcie/pwrseq/pwrseq.c | 83 ++++++++ drivers/pci/probe.c | 2 + include/linux/pcie-pwrseq.h | 24 +++ 14 files changed, 386 insertions(+), 1 deletion(-) create mode 100644 drivers/pci/pcie/pwrseq/Kconfig create mode 100644 drivers/pci/pcie/pwrseq/Makefile create mode 100644 drivers/pci/pcie/pwrseq/pcie-pwrseq-qca6390.c create mode 100644 drivers/pci/pcie/pwrseq/pwrseq.c create mode 100644 include/linux/pcie-pwrseq.h