From patchwork Tue Nov 12 16:19:24 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Bruel X-Patchwork-Id: 13872495 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 DBD85D42BAA for ; Tue, 12 Nov 2024 16:36:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding: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=uwZKNWookk4lIC5CFfymDzUSstCH7d0kemwYeVSNYP4=; b=Hvrh3+zAVRiCLwdvG4SeF+Qyd5 fLNb+zbA90uhWy7vUHpISkGJVPOAQW4EgSezX5QZWS5AE13ANZZjlMGokPaVXx8r2CFaUIPcOZ5uK pv+6IUQjVUPMJvjv2DmwFxKmftjnBl1W1sjIiTvGc3B9W92KCzWlrwPRzIx+n1wI6N0GUo37WWuIF a8pnAlnUIiR5OxBpoVC0T1pcsBqO7Dif8MQcHBXeD4+6X3Y4lKDh0xeB1wy+HNJXUgfj6OhzVtLF6 g3LZ1nQnkharIi96JcEWgpnPXHpVXNKAWSMNmgJgwg/rqCne984m5xyou52EtgrQv8KZOzCx6Io1E Z1Ma21aw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tAtrt-00000004ATG-2dp6; Tue, 12 Nov 2024 16:35:53 +0000 Received: from mx07-00178001.pphosted.com ([185.132.182.106]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tAtk8-000000048kB-2av8 for linux-arm-kernel@lists.infradead.org; Tue, 12 Nov 2024 16:27:54 +0000 Received: from pps.filterd (m0288072.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4ACFkHlb019647; Tue, 12 Nov 2024 17:24:42 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=selector1; bh= uwZKNWookk4lIC5CFfymDzUSstCH7d0kemwYeVSNYP4=; b=p8ZQsSzU7C/kOWDQ 34f21qbE31mcCsqjCoHFIU6xvXnAl/qEOCLem1HvTeZwL+zQSIBqQ+xbk02vdds2 OfwmuaT/snHk22EaBo9gB5zHrmUSvsz2WMks4HvX3rQzzlqtmko2BX4bdyvWzDCx y5LmSF9M7O1KckzPve4sEkCxUemm4GigbGh5ruTVTX/y5WkI7ZpiSlZMipkpSKiP J64kAmsv2WS2lYfel3GnpWA5Nnw8XOgNEjTM+p+avT+i955cxvkOqESH/eXSJway 2KSVz7LRCkfOUontg2cE7EMYZm5MXKqCEjk51+pYBYj+1KQF0dhcnyVDsKcBHTh1 SL1CkQ== Received: from beta.dmz-ap.st.com (beta.dmz-ap.st.com [138.198.100.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 42sx1knr34-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 12 Nov 2024 17:24:42 +0100 (CET) Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-ap.st.com (STMicroelectronics) with ESMTP id A7A9B4005B; Tue, 12 Nov 2024 17:23:21 +0100 (CET) Received: from Webmail-eu.st.com (shfdag1node3.st.com [10.75.129.71]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 5B3542AC018; Tue, 12 Nov 2024 17:20:30 +0100 (CET) Received: from localhost (10.129.178.212) by SHFDAG1NODE3.st.com (10.75.129.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.37; Tue, 12 Nov 2024 17:20:30 +0100 From: Christian Bruel To: , , , , , , , , , , , , CC: , , , , , Christian Bruel Subject: [PATCH 4/5] PCI: stm32: Add PCIe endpoint support for STM32MP25 Date: Tue, 12 Nov 2024 17:19:24 +0100 Message-ID: <20241112161925.999196-5-christian.bruel@foss.st.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241112161925.999196-1-christian.bruel@foss.st.com> References: <20241112161925.999196-1-christian.bruel@foss.st.com> MIME-Version: 1.0 X-Originating-IP: [10.129.178.212] X-ClientProxiedBy: EQNCAS1NODE4.st.com (10.75.129.82) To SHFDAG1NODE3.st.com (10.75.129.71) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-06_09,2024-09-06_01,2024-09-02_01 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241112_082753_006419_641DD004 X-CRM114-Status: GOOD ( 26.63 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add driver to configure the STM32MP25 SoC PCIe Gen2 controller based on the DesignWare PCIe core in endpoint mode. Uses the common reference clock provided by the host. Signed-off-by: Christian Bruel --- drivers/pci/controller/dwc/Kconfig | 12 + drivers/pci/controller/dwc/Makefile | 1 + drivers/pci/controller/dwc/pcie-stm32-ep.c | 433 +++++++++++++++++++++ 3 files changed, 446 insertions(+) create mode 100644 drivers/pci/controller/dwc/pcie-stm32-ep.c diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig index 50a014c2dfd0..29b7f45f82c7 100644 --- a/drivers/pci/controller/dwc/Kconfig +++ b/drivers/pci/controller/dwc/Kconfig @@ -470,4 +470,16 @@ config PCIE_STM32 This driver can also be built as a module. If so, the module will be called pcie-stm32. + +config PCIE_STM32_EP + tristate "STMicroelectronics STM32MP25 PCIe Controller (endpoint mode)" + depends on ARCH_STM32 || COMPILE_TEST + depends on PCI_ENDPOINT + select PCIE_DW_EP + help + Enables endpoint support for DesignWare core based PCIe controller in found + in STM32MP25 SoC. + + This driver can also be built as a module. If so, the module + will be called pcie-stm32-ep. endmenu diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile index 576d99cb3bc5..caebd98f6dd3 100644 --- a/drivers/pci/controller/dwc/Makefile +++ b/drivers/pci/controller/dwc/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o obj-$(CONFIG_PCIE_VISCONTI_HOST) += pcie-visconti.o obj-$(CONFIG_PCIE_RCAR_GEN4) += pcie-rcar-gen4.o obj-$(CONFIG_PCIE_STM32) += pcie-stm32.o +obj-$(CONFIG_PCIE_STM32_EP) += pcie-stm32-ep.o # The following drivers are for devices that use the generic ACPI # pci_root.c driver but don't support standard ECAM config access. diff --git a/drivers/pci/controller/dwc/pcie-stm32-ep.c b/drivers/pci/controller/dwc/pcie-stm32-ep.c new file mode 100644 index 000000000000..9fc43046531d --- /dev/null +++ b/drivers/pci/controller/dwc/pcie-stm32-ep.c @@ -0,0 +1,433 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * STMicroelectronics STM32MP25 PCIe endpoint driver. + * + * Copyright (C) 2024 STMicroelectronics + * Author: Christian Bruel + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "pcie-designware.h" +#include "pcie-stm32.h" + +enum stm32_pcie_ep_link_status { + STM32_PCIE_EP_LINK_DISABLED, + STM32_PCIE_EP_LINK_ENABLED, +}; + +struct stm32_pcie { + struct dw_pcie *pci; + struct regmap *regmap; + struct reset_control *rst; + struct phy *phy; + struct clk *clk; + struct gpio_desc *reset_gpio; + enum stm32_pcie_ep_link_status link_status; + unsigned int perst_irq; +}; + +static const struct of_device_id stm32_pcie_ep_of_match[] = { + { .compatible = "st,stm32mp25-pcie-ep" }, + {}, +}; + +static void stm32_pcie_ep_init(struct dw_pcie_ep *ep) +{ + struct dw_pcie *pci = to_dw_pcie_from_ep(ep); + struct stm32_pcie *stm32_pcie = to_stm32_pcie(pci); + enum pci_barno bar; + + for (bar = BAR_0; bar <= PCI_STD_NUM_BARS; bar++) + dw_pcie_ep_reset_bar(pci, bar); + + /* Defer Completion Requests until link started */ + regmap_update_bits(stm32_pcie->regmap, SYSCFG_PCIECR, + STM32MP25_PCIECR_REQ_RETRY_EN, + STM32MP25_PCIECR_REQ_RETRY_EN); +} + +static int stm32_pcie_enable_link(struct dw_pcie *pci) +{ + struct stm32_pcie *stm32_pcie = to_stm32_pcie(pci); + int ret; + + regmap_update_bits(stm32_pcie->regmap, SYSCFG_PCIECR, + STM32MP25_PCIECR_LTSSM_EN, + STM32MP25_PCIECR_LTSSM_EN); + + ret = dw_pcie_wait_for_link(pci); + if (ret) + return ret; + + regmap_update_bits(stm32_pcie->regmap, SYSCFG_PCIECR, + STM32MP25_PCIECR_REQ_RETRY_EN, + 0); + + return 0; +} + +static void stm32_pcie_disable_link(struct dw_pcie *pci) +{ + struct stm32_pcie *stm32_pcie = to_stm32_pcie(pci); + + regmap_update_bits(stm32_pcie->regmap, SYSCFG_PCIECR, + STM32MP25_PCIECR_REQ_RETRY_EN, + STM32MP25_PCIECR_REQ_RETRY_EN); + + regmap_update_bits(stm32_pcie->regmap, SYSCFG_PCIECR, STM32MP25_PCIECR_LTSSM_EN, 0); +} + +static int stm32_pcie_start_link(struct dw_pcie *pci) +{ + struct stm32_pcie *stm32_pcie = to_stm32_pcie(pci); + int ret; + + if (stm32_pcie->link_status == STM32_PCIE_EP_LINK_ENABLED) { + dev_dbg(pci->dev, "Link is already enabled\n"); + return 0; + } + + ret = stm32_pcie_enable_link(pci); + if (ret) { + dev_err(pci->dev, "PCIe cannot establish link: %d\n", ret); + return ret; + } + + stm32_pcie->link_status = STM32_PCIE_EP_LINK_ENABLED; + + enable_irq(stm32_pcie->perst_irq); + + return 0; +} + +static void stm32_pcie_stop_link(struct dw_pcie *pci) +{ + struct stm32_pcie *stm32_pcie = to_stm32_pcie(pci); + + if (stm32_pcie->link_status == STM32_PCIE_EP_LINK_DISABLED) { + dev_dbg(pci->dev, "Link is already disabled\n"); + return; + } + + disable_irq(stm32_pcie->perst_irq); + + stm32_pcie_disable_link(pci); + + stm32_pcie->link_status = STM32_PCIE_EP_LINK_DISABLED; +} + +static int stm32_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no, + unsigned int type, u16 interrupt_num) +{ + struct dw_pcie *pci = to_dw_pcie_from_ep(ep); + + switch (type) { + case PCI_IRQ_INTX: + return dw_pcie_ep_raise_intx_irq(ep, func_no); + case PCI_IRQ_MSI: + return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num); + default: + dev_err(pci->dev, "UNKNOWN IRQ type\n"); + return -EINVAL; + } + + return 0; +} + +static const struct pci_epc_features stm32_pcie_epc_features = { + .msi_capable = true, + .align = 1 << 16, +}; + +static const struct pci_epc_features* +stm32_pcie_get_features(struct dw_pcie_ep *ep) +{ + return &stm32_pcie_epc_features; +} + +static const struct dw_pcie_ep_ops stm32_pcie_ep_ops = { + .init = stm32_pcie_ep_init, + .raise_irq = stm32_pcie_raise_irq, + .get_features = stm32_pcie_get_features, +}; + +static const struct dw_pcie_ops dw_pcie_ops = { + .start_link = stm32_pcie_start_link, + .stop_link = stm32_pcie_stop_link, +}; + +static int stm32_pcie_enable_resources(struct stm32_pcie *stm32_pcie) +{ + int ret; + + ret = phy_init(stm32_pcie->phy); + if (ret) + return ret; + + ret = clk_prepare_enable(stm32_pcie->clk); + if (ret) + phy_exit(stm32_pcie->phy); + + return ret; +} + +static void stm32_pcie_disable_resources(struct stm32_pcie *stm32_pcie) +{ + clk_disable_unprepare(stm32_pcie->clk); + + phy_exit(stm32_pcie->phy); +} + +static void stm32_pcie_perst_assert(struct dw_pcie *pci) +{ + struct stm32_pcie *stm32_pcie = to_stm32_pcie(pci); + struct device *dev = pci->dev; + + dev_dbg(dev, "PERST asserted by host. Shutting down the PCIe link\n"); + + /* + * Do not try to release resources if the PERST# is + * asserted before the link is started. + */ + if (stm32_pcie->link_status == STM32_PCIE_EP_LINK_DISABLED) { + dev_dbg(pci->dev, "Link is already disabled\n"); + return; + } + + stm32_pcie_disable_link(pci); + + stm32_pcie_disable_resources(stm32_pcie); + + pm_runtime_put_sync(dev); + + stm32_pcie->link_status = STM32_PCIE_EP_LINK_DISABLED; +} + +static void stm32_pcie_perst_deassert(struct dw_pcie *pci) +{ + struct stm32_pcie *stm32_pcie = to_stm32_pcie(pci); + struct device *dev = pci->dev; + struct dw_pcie_ep *ep = &pci->ep; + int ret; + + if (stm32_pcie->link_status == STM32_PCIE_EP_LINK_ENABLED) { + dev_dbg(pci->dev, "Link is already enabled\n"); + return; + } + + dev_dbg(dev, "PERST de-asserted by host. Starting link training\n"); + + ret = pm_runtime_resume_and_get(dev); + if (ret < 0) { + dev_err(dev, "pm runtime resume failed: %d\n", ret); + return; + } + + ret = stm32_pcie_enable_resources(stm32_pcie); + if (ret) { + dev_err(dev, "Failed to enable resources: %d\n", ret); + pm_runtime_put_sync(dev); + return; + } + + ret = dw_pcie_ep_init_registers(ep); + if (ret) { + dev_err(dev, "Failed to complete initialization: %d\n", ret); + stm32_pcie_disable_resources(stm32_pcie); + pm_runtime_put_sync(dev); + return; + } + + pci_epc_init_notify(ep->epc); + + ret = stm32_pcie_enable_link(pci); + if (ret) { + dev_err(dev, "PCIe Cannot establish link: %d\n", ret); + stm32_pcie_disable_resources(stm32_pcie); + pm_runtime_put_sync(dev); + return; + } + + stm32_pcie->link_status = STM32_PCIE_EP_LINK_ENABLED; +} + +static irqreturn_t stm32_pcie_ep_perst_irq_thread(int irq, void *data) +{ + struct stm32_pcie *stm32_pcie = data; + struct dw_pcie *pci = stm32_pcie->pci; + u32 perst; + + perst = gpiod_get_value(stm32_pcie->reset_gpio); + if (perst) + stm32_pcie_perst_assert(pci); + else + stm32_pcie_perst_deassert(pci); + + return IRQ_HANDLED; +} + +static int stm32_add_pcie_ep(struct stm32_pcie *stm32_pcie, + struct platform_device *pdev) +{ + struct dw_pcie *pci = stm32_pcie->pci; + struct dw_pcie_ep *ep = &pci->ep; + struct device *dev = &pdev->dev; + int ret; + + ret = regmap_update_bits(stm32_pcie->regmap, SYSCFG_PCIECR, + STM32MP25_PCIECR_TYPE_MASK, + STM32MP25_PCIECR_EP); + if (ret) + return ret; + + ret = pm_runtime_resume_and_get(dev); + if (ret < 0) { + dev_err(dev, "pm runtime resume failed: %d\n", ret); + return ret; + } + + reset_control_assert(stm32_pcie->rst); + reset_control_deassert(stm32_pcie->rst); + + ep->ops = &stm32_pcie_ep_ops; + + ret = dw_pcie_ep_init(ep); + if (ret) { + dev_err(dev, "failed to initialize ep: %d\n", ret); + pm_runtime_put_sync(dev); + return ret; + } + + ret = stm32_pcie_enable_resources(stm32_pcie); + if (ret) { + dev_err(dev, "failed to enable resources: %d\n", ret); + dw_pcie_ep_deinit(ep); + pm_runtime_put_sync(dev); + return ret; + } + + ret = dw_pcie_ep_init_registers(ep); + if (ret) { + dev_err(dev, "Failed to initialize DWC endpoint registers\n"); + stm32_pcie_disable_resources(stm32_pcie); + dw_pcie_ep_deinit(ep); + pm_runtime_put_sync(dev); + return ret; + } + + pci_epc_init_notify(ep->epc); + + return 0; +} + +static int stm32_pcie_probe(struct platform_device *pdev) +{ + struct stm32_pcie *stm32_pcie; + struct dw_pcie *dw; + struct device *dev = &pdev->dev; + int ret; + + stm32_pcie = devm_kzalloc(dev, sizeof(*stm32_pcie), GFP_KERNEL); + if (!stm32_pcie) + return -ENOMEM; + + dw = devm_kzalloc(dev, sizeof(*dw), GFP_KERNEL); + if (!dw) + return -ENOMEM; + stm32_pcie->pci = dw; + + dw->dev = dev; + dw->ops = &dw_pcie_ops; + + stm32_pcie->regmap = syscon_regmap_lookup_by_compatible("st,stm32mp25-syscfg"); + if (IS_ERR(stm32_pcie->regmap)) + return dev_err_probe(dev, PTR_ERR(stm32_pcie->regmap), + "No syscfg specified\n"); + + stm32_pcie->phy = devm_phy_get(dev, "pcie-phy"); + if (IS_ERR(stm32_pcie->phy)) + return dev_err_probe(dev, PTR_ERR(stm32_pcie->phy), + "failed to get pcie-phy\n"); + + stm32_pcie->clk = devm_clk_get(dev, "core"); + if (IS_ERR(stm32_pcie->clk)) + return dev_err_probe(dev, PTR_ERR(stm32_pcie->clk), + "Failed to get PCIe clock source\n"); + + stm32_pcie->rst = devm_reset_control_get_exclusive(dev, "core"); + if (IS_ERR(stm32_pcie->rst)) + return dev_err_probe(dev, PTR_ERR(stm32_pcie->rst), + "Failed to get PCIe reset\n"); + + stm32_pcie->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_IN); + if (IS_ERR(stm32_pcie->reset_gpio)) + return dev_err_probe(dev, PTR_ERR(stm32_pcie->reset_gpio), + "Failed to get reset GPIO\n"); + + ret = phy_set_mode(stm32_pcie->phy, PHY_MODE_PCIE); + if (ret) + return ret; + + platform_set_drvdata(pdev, stm32_pcie); + + ret = devm_pm_runtime_enable(dev); + if (ret < 0) { + dev_err(dev, "Failed to enable pm runtime %d\n", ret); + return ret; + } + + stm32_pcie->perst_irq = gpiod_to_irq(stm32_pcie->reset_gpio); + + /* Will be enabled in start_link when device is initialized. */ + irq_set_status_flags(stm32_pcie->perst_irq, IRQ_NOAUTOEN); + + ret = devm_request_threaded_irq(dev, stm32_pcie->perst_irq, NULL, + stm32_pcie_ep_perst_irq_thread, + IRQF_TRIGGER_RISING | + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + "perst_irq", stm32_pcie); + if (ret) { + dev_err(dev, "Failed to request PERST IRQ: %d\n", ret); + return ret; + } + + return stm32_add_pcie_ep(stm32_pcie, pdev); +} + +static void stm32_pcie_remove(struct platform_device *pdev) +{ + struct stm32_pcie *stm32_pcie = platform_get_drvdata(pdev); + struct dw_pcie_ep *ep = &stm32_pcie->pci->ep; + + disable_irq(stm32_pcie->perst_irq); + + dw_pcie_ep_deinit(ep); + + stm32_pcie_disable_resources(stm32_pcie); + + pm_runtime_put_sync(&pdev->dev); +} + +static struct platform_driver stm32_pcie_ep_driver = { + .probe = stm32_pcie_probe, + .remove_new = stm32_pcie_remove, + .driver = { + .name = "stm32-ep-pcie", + .of_match_table = stm32_pcie_ep_of_match, + }, +}; + +module_platform_driver(stm32_pcie_ep_driver); + +MODULE_AUTHOR("Christian Bruel "); +MODULE_DESCRIPTION("STM32MP25 PCIe Endpoint Controller driver"); +MODULE_LICENSE("GPL"); +MODULE_DEVICE_TABLE(of, stm32_pcie_ep_of_match);