From patchwork Sat Mar 30 04:19:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Damien Le Moal X-Patchwork-Id: 13611488 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 E2032CD1288 for ; Sat, 30 Mar 2024 04:22:25 +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-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=A/piEX1O5P9KxuNUeWsXWKz/tGoOfrQ+kIYNu4il3cs=; b=tm5UYfdRy4mV5t b7dmkNCno1WoQpBnCyjzUa+w/ZU5xogfaUQRT6akWMBc7z8xUiJk5/mLBR2o9S4lvGJM6C4KSRSOd rHFLdUaV3ipG+SsTDFFOoYdIxbcjm969YSpzqlQJwxEIdJanQCaXMOcl4ZpojHbOngnbPXlmXZM0l qh7tlJkqsRfwMEQVK4bZyFyCt3JiVaEHoCVvE0AdccJEqOe4SRuo+ypva4rHXAnhSYhxtdOEc1ag3 l/g/BvIKN2x/tpydjXBHNtbhafSWU/lnBDEwT6+YmUG6dWA/PpYnXyFW0gyyohqPnIojuTl09LucL Pg0LnKytPm0Tg0nvZkBw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rqQET-00000002kwG-3kEU; Sat, 30 Mar 2024 04:22:17 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rqQCi-00000002kB0-2MWS; Sat, 30 Mar 2024 04:20:30 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id E3A576023A; Sat, 30 Mar 2024 04:20:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDB43C433C7; Sat, 30 Mar 2024 04:20:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711772427; bh=1t0jdbxFDf1tbV2RmYerTpuKKJAQm3L4Ecrn9VCA2uE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MUy8iFCErHCg8kZvCf3enafxPYDuNpzeJ1SOS/lFtGYYve0i1qyMwYaqaC/05vFKD 9ChSG90z/+t2vuHxcnvlQyTRVBMJhE1uXhdT3hWAl+QNeN1TJi/YOuZ/0LhUkxKvwv WutQRPY0KanIw+5MCtR69Plvw4s9mIGnk0MK2XvUiI60YXeuLjka9LoBKapvPa8Ive kCFp/BiG3D2wyxIedGrqpDUMsSPooATmWwLTBboxdzJDwci5vhd50txUGRuSVefSkf 2G5qMHMbSbYxNgQgrLv+A7yJVOUPg4689+WcRZH3+hriorFUho1nurUuPpp3xMmz9+ 1xPbrwF3qw6sg== From: Damien Le Moal To: Manivannan Sadhasivam , Lorenzo Pieralisi , Kishon Vijay Abraham I , Shawn Lin , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= , Bjorn Helgaas , Heiko Stuebner , linux-pci@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , devicetree@vger.kernel.org Cc: linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Rick Wertenbroek , Wilfred Mallawa , Niklas Cassel Subject: [PATCH v2 18/18] PCI: rockchip-ep: Handle PERST# signal in endpoint mode Date: Sat, 30 Mar 2024 13:19:28 +0900 Message-ID: <20240330041928.1555578-19-dlemoal@kernel.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240330041928.1555578-1-dlemoal@kernel.org> References: <20240330041928.1555578-1-dlemoal@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240329_212028_753996_62D4D9C4 X-CRM114-Status: GOOD ( 23.52 ) X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org Currently, the Rockchip PCIe endpoint controller driver does not handle PERST# signal, which prevents detecting when link training should actually be started or if the host reset the device. This however can be supported using the controller ep_gpio, set as an input GPIO for endpoint mode. Modify the endpoint rockchip driver to get the ep_gpio and its associated interrupt which is serviced using a threaded IRQ with the function rockchip_pcie_ep_perst_irq_thread() as handler. This handler function notifies a link down event corresponding to the RC side asserting the PERST# signal using pci_epc_linkdown() when the gpio is high. Once the gpio value goes down, corresponding to the RC de-asserting the PERST# signal, link training is started. The polarity of the gpio interrupt trigger is changed from high to low after the RC asserted PERST#, and conversely changed from low to high after the RC de-asserts PERST#. Signed-off-by: Damien Le Moal --- drivers/pci/controller/pcie-rockchip-ep.c | 118 +++++++++++++++++++++- drivers/pci/controller/pcie-rockchip.c | 12 +-- 2 files changed, 122 insertions(+), 8 deletions(-) diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c index 4006e7dee71a..e098c5fb6d59 100644 --- a/drivers/pci/controller/pcie-rockchip-ep.c +++ b/drivers/pci/controller/pcie-rockchip-ep.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "pcie-rockchip.h" @@ -50,6 +51,9 @@ struct rockchip_pcie_ep { u64 irq_pci_addr; u8 irq_pci_fn; u8 irq_pending; + int perst_irq; + bool perst_asserted; + bool link_up; struct delayed_work link_training; }; @@ -464,13 +468,17 @@ static int rockchip_pcie_ep_start(struct pci_epc *epc) rockchip_pcie_write(rockchip, cfg, PCIE_CORE_PHY_FUNC_CFG); + if (rockchip->ep_gpio) + enable_irq(ep->perst_irq); + /* Enable configuration and start link training */ rockchip_pcie_write(rockchip, PCIE_CLIENT_LINK_TRAIN_ENABLE | PCIE_CLIENT_CONF_ENABLE, PCIE_CLIENT_CONFIG); - schedule_delayed_work(&ep->link_training, 0); + if (!rockchip->ep_gpio) + schedule_delayed_work(&ep->link_training, 0); return 0; } @@ -480,6 +488,11 @@ static void rockchip_pcie_ep_stop(struct pci_epc *epc) struct rockchip_pcie_ep *ep = epc_get_drvdata(epc); struct rockchip_pcie *rockchip = &ep->rockchip; + if (rockchip->ep_gpio) { + ep->perst_asserted = true; + disable_irq(ep->perst_irq); + } + cancel_delayed_work_sync(&ep->link_training); /* Stop link training and disable configuration */ @@ -542,6 +555,13 @@ static void rockchip_pcie_ep_link_training(struct work_struct *work) if (!rockchip_pcie_ep_link_up(rockchip)) goto again; + /* + * If PERST was asserted while polling the link, do not notify + * the function. + */ + if (ep->perst_asserted) + return; + val = rockchip_pcie_read(rockchip, PCIE_CLIENT_BASIC_STATUS0); dev_info(dev, "Link UP (Negociated speed: %sGT/s, width: x%lu)\n", @@ -551,6 +571,7 @@ static void rockchip_pcie_ep_link_training(struct work_struct *work) /* Notify the function */ pci_epc_linkup(ep->epc); + ep->link_up = true; return; @@ -558,6 +579,94 @@ static void rockchip_pcie_ep_link_training(struct work_struct *work) schedule_delayed_work(&ep->link_training, msecs_to_jiffies(5)); } +static void rockchip_pcie_ep_perst_assert(struct rockchip_pcie_ep *ep) +{ + struct rockchip_pcie *rockchip = &ep->rockchip; + struct device *dev = rockchip->dev; + + dev_dbg(dev, "PERST asserted, link down\n"); + + if (ep->perst_asserted) + return; + + ep->perst_asserted = true; + + cancel_delayed_work_sync(&ep->link_training); + + if (ep->link_up) { + pci_epc_linkdown(ep->epc); + ep->link_up = false; + } +} + +static void rockchip_pcie_ep_perst_deassert(struct rockchip_pcie_ep *ep) +{ + struct rockchip_pcie *rockchip = &ep->rockchip; + struct device *dev = rockchip->dev; + + dev_dbg(dev, "PERST de-asserted, starting link training\n"); + + if (!ep->perst_asserted) + return; + + ep->perst_asserted = false; + + /* Enable link re-training */ + rockchip_pcie_ep_retrain_link(rockchip); + + /* Start link training */ + schedule_delayed_work(&ep->link_training, 0); +} + +static irqreturn_t rockchip_pcie_ep_perst_irq_thread(int irq, void *data) +{ + struct pci_epc *epc = data; + struct rockchip_pcie_ep *ep = epc_get_drvdata(epc); + struct rockchip_pcie *rockchip = &ep->rockchip; + u32 perst = gpiod_get_value(rockchip->ep_gpio); + + if (perst) + rockchip_pcie_ep_perst_assert(ep); + else + rockchip_pcie_ep_perst_deassert(ep); + + irq_set_irq_type(ep->perst_irq, + (perst ? IRQF_TRIGGER_HIGH : IRQF_TRIGGER_LOW)); + + return IRQ_HANDLED; +} + +static int rockchip_pcie_ep_setup_irq(struct pci_epc *epc) +{ + struct rockchip_pcie_ep *ep = epc_get_drvdata(epc); + struct rockchip_pcie *rockchip = &ep->rockchip; + struct device *dev = rockchip->dev; + int ret; + + if (!rockchip->ep_gpio) + return 0; + + /* PCIe reset interrupt */ + ep->perst_irq = gpiod_to_irq(rockchip->ep_gpio); + if (ep->perst_irq < 0) { + dev_err(dev, "No corresponding IRQ for PERST GPIO\n"); + return ep->perst_irq; + } + + ep->perst_asserted = true; + irq_set_status_flags(ep->perst_irq, IRQ_NOAUTOEN); + ret = devm_request_threaded_irq(dev, ep->perst_irq, NULL, + rockchip_pcie_ep_perst_irq_thread, + IRQF_TRIGGER_HIGH | IRQF_ONESHOT, + "pcie-ep-perst", epc); + if (ret) { + dev_err(dev, "Request PERST GPIO IRQ failed %d\n", ret); + return ret; + } + + return 0; +} + static const struct pci_epc_features rockchip_pcie_epc_features = { .linkup_notifier = true, .msi_capable = true, @@ -721,6 +830,7 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev) rockchip->is_rc = false; rockchip->dev = dev; INIT_DELAYED_WORK(&ep->link_training, rockchip_pcie_ep_link_training); + ep->link_up = false; epc = devm_pci_epc_create(dev, &rockchip_pcie_epc_ops); if (IS_ERR(epc)) { @@ -748,7 +858,13 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev) /* Only enable function 0 by default */ rockchip_pcie_write(rockchip, BIT(0), PCIE_CORE_PHY_FUNC_CFG); + err = rockchip_pcie_ep_setup_irq(epc); + if (err < 0) + goto err_uninit_port; + return 0; +err_uninit_port: + rockchip_pcie_deinit_phys(rockchip); err_release_resources: rockchip_pcie_ep_release_resources(ep); err_disable_clocks: diff --git a/drivers/pci/controller/pcie-rockchip.c b/drivers/pci/controller/pcie-rockchip.c index dbec700ba9f9..3938c0b6b5a9 100644 --- a/drivers/pci/controller/pcie-rockchip.c +++ b/drivers/pci/controller/pcie-rockchip.c @@ -119,13 +119,11 @@ int rockchip_pcie_parse_dt(struct rockchip_pcie *rockchip) return PTR_ERR(rockchip->aclk_rst); } - if (rockchip->is_rc) { - rockchip->ep_gpio = devm_gpiod_get_optional(dev, "ep", - GPIOD_OUT_HIGH); - if (IS_ERR(rockchip->ep_gpio)) - return dev_err_probe(dev, PTR_ERR(rockchip->ep_gpio), - "failed to get ep GPIO\n"); - } + rockchip->ep_gpio = devm_gpiod_get_optional(dev, "ep", + rockchip->is_rc ? GPIOD_OUT_HIGH : GPIOD_IN); + if (IS_ERR(rockchip->ep_gpio)) + return dev_err_probe(dev, PTR_ERR(rockchip->ep_gpio), + "failed to get ep GPIO\n"); rockchip->aclk_pcie = devm_clk_get(dev, "aclk"); if (IS_ERR(rockchip->aclk_pcie)) {