From patchwork Wed Sep 8 06:59:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Zhu X-Patchwork-Id: 12480447 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E610C433EF for ; Wed, 8 Sep 2021 07:22:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FAE161102 for ; Wed, 8 Sep 2021 07:22:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347872AbhIHHXb (ORCPT ); Wed, 8 Sep 2021 03:23:31 -0400 Received: from inva020.nxp.com ([92.121.34.13]:47828 "EHLO inva020.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235185AbhIHHX3 (ORCPT ); Wed, 8 Sep 2021 03:23:29 -0400 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 53DFF1A2E4A; Wed, 8 Sep 2021 09:22:21 +0200 (CEST) Received: from aprdc01srsp001v.ap-rdc01.nxp.com (aprdc01srsp001v.ap-rdc01.nxp.com [165.114.16.16]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id EE7EC1A4595; Wed, 8 Sep 2021 09:22:20 +0200 (CEST) Received: from localhost.localdomain (shlinux2.ap.freescale.net [10.192.224.44]) by aprdc01srsp001v.ap-rdc01.nxp.com (Postfix) with ESMTP id EFB8C183AD45; Wed, 8 Sep 2021 15:22:19 +0800 (+08) From: Richard Zhu To: l.stach@pengutronix.de, bhelgaas@google.com, lorenzo.pieralisi@arm.com Cc: linux-pci@vger.kernel.org, linux-imx@nxp.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de, Richard Zhu Subject: [PATCH 3/3] PCI: imx: add compliance tests mode to enable measure signal quality Date: Wed, 8 Sep 2021 14:59:26 +0800 Message-Id: <1631084366-24785-3-git-send-email-hongxing.zhu@nxp.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1631084366-24785-1-git-send-email-hongxing.zhu@nxp.com> References: <1631084366-24785-1-git-send-email-hongxing.zhu@nxp.com> X-Virus-Scanned: ClamAV using ClamSMTP Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Refer to the system board signal Quality of PCIe archiecture PHY test specification. Signal quality tests can be executed with devices in the polling.compliance state. To let the device support polling.compliance stat, the clocks and powers shouldn't be turned off during the compliance tests although the PHY link might be down. Add the i.MX PCIe compliance tests mode enable option to keep the and powers on, and finish the driver probe without error return. Use the "pcie_cmp_enabled=yes" in kernel command line to enable the compliance tests mode. Signed-off-by: Richard Zhu --- drivers/pci/controller/dwc/pci-imx6.c | 41 +++++++++++++++++++++------ 1 file changed, 33 insertions(+), 8 deletions(-) diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index 129928e42f84..3aef0e86f1c2 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -143,6 +143,7 @@ struct imx6_pcie { #define PHY_RX_OVRD_IN_LO_RX_DATA_EN BIT(5) #define PHY_RX_OVRD_IN_LO_RX_PLL_EN BIT(3) +static int imx6_pcie_cmp_enabled; static int imx6_pcie_clk_enable(struct imx6_pcie *imx6_pcie); static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie); @@ -748,10 +749,12 @@ static int imx6_pcie_start_link(struct dw_pcie *pci) * started in Gen2 mode, there is a possibility the devices on the * bus will not be detected at all. This happens with PCIe switches. */ - tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); - tmp &= ~PCI_EXP_LNKCAP_SLS; - tmp |= PCI_EXP_LNKCAP_SLS_2_5GB; - dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp); + if (!imx6_pcie_cmp_enabled) { + tmp = dw_pcie_readl_dbi(pci, offset + PCI_EXP_LNKCAP); + tmp &= ~PCI_EXP_LNKCAP_SLS; + tmp |= PCI_EXP_LNKCAP_SLS_2_5GB; + dw_pcie_writel_dbi(pci, offset + PCI_EXP_LNKCAP, tmp); + } /* Start LTSSM. */ imx6_pcie_ltssm_enable(dev); @@ -812,9 +815,12 @@ static int imx6_pcie_start_link(struct dw_pcie *pci) dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG0), dw_pcie_readl_dbi(pci, PCIE_PORT_DEBUG1)); imx6_pcie_reset_phy(imx6_pcie); - imx6_pcie_clk_disable(imx6_pcie); - if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) - regulator_disable(imx6_pcie->vpcie); + if (!imx6_pcie_cmp_enabled) { + imx6_pcie_clk_disable(imx6_pcie); + if (imx6_pcie->vpcie + && regulator_is_enabled(imx6_pcie->vpcie) > 0) + regulator_disable(imx6_pcie->vpcie); + } return ret; } @@ -1010,6 +1016,17 @@ static const struct dev_pm_ops imx6_pcie_pm_ops = { imx6_pcie_resume_noirq) }; +static int __init imx6_pcie_compliance_test_enable(char *str) +{ + if (!strcmp(str, "yes")) { + pr_info("Enable the i.MX PCIe TX/CLK compliance tests mode.\n"); + imx6_pcie_cmp_enabled = 1; + } + return 1; +} + +__setup("pcie_cmp_enabled=", imx6_pcie_compliance_test_enable); + static int imx6_pcie_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -1187,8 +1204,16 @@ static int imx6_pcie_probe(struct platform_device *pdev) return ret; ret = dw_pcie_host_init(&pci->pp); - if (ret < 0) + if (ret < 0) { + if (imx6_pcie_cmp_enabled) { + /* The PCIE clocks and powers wouldn't be turned off */ + dev_info(dev, "To do the compliance tests.\n"); + ret = 0; + } else { + dev_err(dev, "Unable to add pcie port.\n"); + } return ret; + } if (pci_msi_enabled()) { u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);