From patchwork Mon Oct 7 04:12:18 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: 13824041 X-Patchwork-Delegate: manivannanece23@gmail.com Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 102102AF1B; Mon, 7 Oct 2024 04:12:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728274368; cv=none; b=qw5eRXYHQk6BsfKt+Bky/AtrrZQ0/OFrOnEnS5+5lqV5ls0sgbeCKFycd8YQfBl5GmIcqyy5ZZX/Y4bvYzuqJUW3IFoIp6qmqh7XK9+lFBycTMJl4gIgF+8zQANLHwyRRrjGp7Ne7XGgIlVbLdxugr5OnTs2OHLcKo6hthZxNyM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728274368; c=relaxed/simple; bh=mg7tQ5KHeQvXnXHQ9fqxsTpUTZBgoStFDRnvXossBYY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KuaokhRuWvFlDjYveRgh9qOzGE3bEVylP42iZDwxwjVdBhp+dYSWIxkM7rH+Tp2ortJzoBXGRT2q6TlN9/2rKafIDiAO6ICUyQcqKkQMWnSqm6CtrN9ATGWxCOGHfL7JQJCIE/Q6V7Sx/ILCPMOT33JQ4mLSAE+5AonHOgHVovI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nDm/Jb96; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nDm/Jb96" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2051CC4CED0; Mon, 7 Oct 2024 04:12:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1728274367; bh=mg7tQ5KHeQvXnXHQ9fqxsTpUTZBgoStFDRnvXossBYY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nDm/Jb96cY5akeCsymnQsrfII208DE8ciggBFC/LaNODBkjg6dCOUGIFGN7v60SSp VXwvlE/xHnRSLlsuuXEvEhGZ6ye0MWmLz05dRTY71qX34VAM1J+ZtI4qWu36eYq8Ci HbIcQSQG43ZkWhxtfCBh49mUQjH5bmbGzWom5TLzhWYuT2p0iv/kE32zuwB+dJ2vgQ n1/Yob8NaeBegNOEAzyGkZlzYkiTloE5+Sg/9NE+EptO6T+ikb0LaWMhBg90nDkV/9 oVuX0qaL4VqUMNDuZIoME0Ey7koWVkGw7AaUOoTgcbLqvEoM2SvDRazW+cMa3aUUne LcW+/vYMkzh/Q== 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, Rick Wertenbroek , Wilfred Mallawa , Niklas Cassel Subject: [PATCH v3 12/12] PCI: rockchip-ep: Handle PERST# signal in endpoint mode Date: Mon, 7 Oct 2024 13:12:18 +0900 Message-ID: <20241007041218.157516-13-dlemoal@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241007041218.157516-1-dlemoal@kernel.org> References: <20241007041218.157516-1-dlemoal@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 af50432525b4..c70a64c37a56 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; }; @@ -462,13 +466,17 @@ 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; } @@ -478,6 +486,11 @@ 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 */ @@ -540,6 +553,13 @@ 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", @@ -549,6 +569,7 @@ static void rockchip_pcie_ep_link_training(struct work_struct *work) /* Notify the function */ pci_epc_linkup(ep->epc); + ep->link_up = true; return; @@ -556,6 +577,94 @@ 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, @@ -719,6 +828,7 @@ 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)) { @@ -751,7 +861,13 @@ static int rockchip_pcie_ep_probe(struct platform_device *pdev) pci_epc_init_notify(epc); + 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 154e78819e6e..bcb1c9266c56 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_LOW); - 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_LOW : 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)) {