From patchwork Thu Oct 17 01:58:48 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: 13839279 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 88A3FD2F7DE for ; Thu, 17 Oct 2024 01:59:28 +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=Nl8jbpNdqliStTdwYLzdcAxfAejla1guq1ZUom8nrN0=; b=Ep1BOKC13FTJWc EAG+ov141drGBMymI2AgncQWH732qk+QrVvlip0H9uM5hMm1qy3c2qzjxP8H7fs7OJtGIYRyHAs/s XU7Bo0u7MAJ0PDV63jtQziS+IeZqEfveoY8OEg8UphC5sqOzYkuWDf6U0N0WOCJH2O295UcDkB7HL AKLFXybexcTlKKRM/SJui//ijDKzRRVnYDYHRZCq6Gnd40DbCz7kKuC7sXST1fhQse6qoTgc04RT5 Oky/ihq2GzhkuWYWCxW6NBowY6pcDZqf4nSEH3hrSU1+YhzwWcb50saapGR8UVfMNkJUiKgxPzdOj +WHsTYw9kUw6nr0jWCuw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t1FnR-0000000DV5S-2xYr; Thu, 17 Oct 2024 01:59:25 +0000 Received: from nyc.source.kernel.org ([2604:1380:45d1:ec00::3]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t1FnL-0000000DUzJ-1lc2 for linux-rockchip@lists.infradead.org; Thu, 17 Oct 2024 01:59:21 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id AD917A40DE4; Thu, 17 Oct 2024 01:59:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F149C4CED0; Thu, 17 Oct 2024 01:59:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729130358; bh=ueCDGH3nxJnYp5coBf9bjy2Kha4NZeZU4aWU9o3/8W4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gssfgivM4bDbm2A9irgS5VJIwPmQT2q87K6WLmlpCCPzlixtx3pqZQGtK/G+LsqJp XDvzjYeJjBzwxTYnWOUTZOrG1SVZTxlLfWbMR3VqzvP4yCl7B9/6Jx2cfbbyiVw3X/ Hkqq2ZSmZ+jeUEHKjof4xnvFW0vyKOLiFdQj4EgA+V99YziCEwzO+FhkqIzibQRiFg G3o1X4WmYtArLFQrHP21eASAmdvO0hE5J19Pb6cQCho0Xa9oXiqS1hU9gxKpouD3sA ZpXPl+Zzc/THHYDpQAmWqimJm+BdC319vi6KCvD4ziuqGtFPs647+XDAkK+fVDIFAj tsUq+CZ3tM7ng== From: Damien Le Moal To: Manivannan Sadhasivam , Lorenzo Pieralisi , Kishon Vijay Abraham I , Shawn Lin , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= , Bjorn Helgaas , linux-pci@vger.kernel.org, Rob Herring , Krzysztof Kozlowski , Conor Dooley , Heiko Stuebner , devicetree@vger.kernel.org Cc: linux-rockchip@lists.infradead.org, Rick Wertenbroek , Niklas Cassel Subject: [PATCH v5 13/14] PCI: rockchip-ep: Handle PERST# signal in endpoint mode Date: Thu, 17 Oct 2024 10:58:48 +0900 Message-ID: <20241017015849.190271-14-dlemoal@kernel.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241017015849.190271-1-dlemoal@kernel.org> References: <20241017015849.190271-1-dlemoal@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241016_185919_621296_0EBB8D9C X-CRM114-Status: GOOD ( 26.68 ) 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 the PERST# signal, which prevents detecting when link training should actually be started or if the host resets the device. This however can be supported using the controller reset_gpios property set as an input GPIO for endpoint mode. Modify the rockchip PCI endpoint controller driver to get the reset_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#. Also, given that the host mode controller and the endpoint mode controller use two different property names for the same PERST# signal (ep_gpios property and reset_gpios property respectively), for clarity, rename the ep_gpio field of struct rockchip_pcie to perst_gpio. Signed-off-by: Damien Le Moal --- drivers/pci/controller/pcie-rockchip-ep.c | 124 +++++++++++++++++++- drivers/pci/controller/pcie-rockchip-host.c | 4 +- drivers/pci/controller/pcie-rockchip.c | 16 +-- drivers/pci/controller/pcie-rockchip.h | 2 +- 4 files changed, 133 insertions(+), 13 deletions(-) diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c index 43480706b8f4..19cfba5230a2 100644 --- a/drivers/pci/controller/pcie-rockchip-ep.c +++ b/drivers/pci/controller/pcie-rockchip-ep.c @@ -10,6 +10,7 @@ #include #include +#include #include #include #include @@ -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; }; @@ -467,13 +471,17 @@ static int rockchip_pcie_ep_start(struct pci_epc *epc) rockchip_pcie_write(rockchip, cfg, PCIE_CORE_PHY_FUNC_CFG); + if (rockchip->perst_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->perst_gpio) + schedule_delayed_work(&ep->link_training, 0); return 0; } @@ -483,6 +491,11 @@ 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->perst_gpio) { + ep->perst_asserted = true; + disable_irq(ep->perst_irq); + } + cancel_delayed_work_sync(&ep->link_training); /* Stop link training and disable configuration */ @@ -548,6 +561,13 @@ 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 (Negotiated speed: %sGT/s, width: x%lu)\n", @@ -557,6 +577,7 @@ static void rockchip_pcie_ep_link_training(struct work_struct *work) /* Notify the function */ pci_epc_linkup(ep->epc); + ep->link_up = true; return; @@ -564,6 +585,97 @@ 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; + + dev_dbg(rockchip->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; + + dev_dbg(rockchip->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->perst_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->perst_gpio) + return 0; + + /* PCIe reset interrupt */ + ep->perst_irq = gpiod_to_irq(rockchip->perst_gpio); + if (ep->perst_irq < 0) { + dev_err(dev, "No IRQ for PERST# GPIO\n"); + return ep->perst_irq; + } + + /* + * The perst_gpio is active low, so when it is inactive on start, it + * is high and will trigger the perst_irq handler. So treat this initial + * IRQ as a dummy one by faking the host asserting PERST#. + */ + 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, @@ -757,11 +869,17 @@ 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_exit_ob_mem: - rockchip_pcie_ep_exit_ob_mem(ep); +err_uninit_port: + rockchip_pcie_deinit_phys(rockchip); err_disable_clocks: rockchip_pcie_disable_clocks(rockchip); +err_exit_ob_mem: + rockchip_pcie_ep_exit_ob_mem(ep); return err; } diff --git a/drivers/pci/controller/pcie-rockchip-host.c b/drivers/pci/controller/pcie-rockchip-host.c index cbec71114825..7471d9fd18bc 100644 --- a/drivers/pci/controller/pcie-rockchip-host.c +++ b/drivers/pci/controller/pcie-rockchip-host.c @@ -294,7 +294,7 @@ static int rockchip_pcie_host_init_port(struct rockchip_pcie *rockchip) int err, i = MAX_LANE_NUM; u32 status; - gpiod_set_value_cansleep(rockchip->ep_gpio, 0); + gpiod_set_value_cansleep(rockchip->perst_gpio, 0); err = rockchip_pcie_init_port(rockchip); if (err) @@ -323,7 +323,7 @@ static int rockchip_pcie_host_init_port(struct rockchip_pcie *rockchip) PCIE_CLIENT_CONFIG); msleep(PCIE_T_PVPERL_MS); - gpiod_set_value_cansleep(rockchip->ep_gpio, 1); + gpiod_set_value_cansleep(rockchip->perst_gpio, 1); msleep(PCIE_T_RRS_READY_MS); diff --git a/drivers/pci/controller/pcie-rockchip.c b/drivers/pci/controller/pcie-rockchip.c index 154e78819e6e..b9ade7632e11 100644 --- a/drivers/pci/controller/pcie-rockchip.c +++ b/drivers/pci/controller/pcie-rockchip.c @@ -119,13 +119,15 @@ 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"); - } + if (rockchip->is_rc) + rockchip->perst_gpio = devm_gpiod_get_optional(dev, "ep", + GPIOD_OUT_LOW); + else + rockchip->perst_gpio = devm_gpiod_get_optional(dev, "reset", + GPIOD_IN); + if (IS_ERR(rockchip->perst_gpio)) + return dev_err_probe(dev, PTR_ERR(rockchip->perst_gpio), + "failed to get PERST# GPIO\n"); rockchip->aclk_pcie = devm_clk_get(dev, "aclk"); if (IS_ERR(rockchip->aclk_pcie)) { diff --git a/drivers/pci/controller/pcie-rockchip.h b/drivers/pci/controller/pcie-rockchip.h index 24796176f658..a51b087ce878 100644 --- a/drivers/pci/controller/pcie-rockchip.h +++ b/drivers/pci/controller/pcie-rockchip.h @@ -329,7 +329,7 @@ struct rockchip_pcie { struct regulator *vpcie3v3; /* 3.3V power supply */ struct regulator *vpcie1v8; /* 1.8V power supply */ struct regulator *vpcie0v9; /* 0.9V power supply */ - struct gpio_desc *ep_gpio; + struct gpio_desc *perst_gpio; u32 lanes; u8 lanes_map; int link_gen;