From patchwork Wed Jan 5 07:43:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hongxing Zhu X-Patchwork-Id: 12704139 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3401C433F5 for ; Wed, 5 Jan 2022 08:13:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238378AbiAEINI (ORCPT ); Wed, 5 Jan 2022 03:13:08 -0500 Received: from inva020.nxp.com ([92.121.34.13]:39624 "EHLO inva020.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238361AbiAEINE (ORCPT ); Wed, 5 Jan 2022 03:13:04 -0500 Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 1FE311A12AA; Wed, 5 Jan 2022 09:12:58 +0100 (CET) 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 B15301A2374; Wed, 5 Jan 2022 09:12:57 +0100 (CET) Received: from localhost.localdomain (shlinux2.ap.freescale.net [10.192.224.44]) by aprdc01srsp001v.ap-rdc01.nxp.com (Postfix) with ESMTP id 6D6FE183AD6D; Wed, 5 Jan 2022 16:12:56 +0800 (+08) From: Richard Zhu To: l.stach@pengutronix.de, bhelgaas@google.com, broonie@kernel.org, lorenzo.pieralisi@arm.com, jingoohan1@gmail.com, festevam@gmail.com Cc: hongxing.zhu@nxp.com, stable@vger.kernel.org, linux-pci@vger.kernel.org, linux-imx@nxp.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de Subject: [PATCH v5 6/6] PCI: imx6: Add the compliance tests mode support Date: Wed, 5 Jan 2022 15:43:22 +0800 Message-Id: <1641368602-20401-7-git-send-email-hongxing.zhu@nxp.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1641368602-20401-1-git-send-email-hongxing.zhu@nxp.com> References: <1641368602-20401-1-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(for example: jitters, differential eye opening and so on ) 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 when the probe of device driver is failed. Based on CLB(Compliance Load Board) Test Fixture and so on test equipments, the PHY link would be down during the compliance tests. Refer to this scenario, add the i.MX PCIe compliance tests mode enable support, and keep the clocks and powers on, and finish the driver probe without error return. Use the "pci_imx6.compliance=1" in kernel command line to enable the compliance tests mode. Signed-off-by: Richard Zhu --- drivers/pci/controller/dwc/pci-imx6.c | 47 ++++++++++++++++++--------- 1 file changed, 31 insertions(+), 16 deletions(-) diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index 61b25f5cbf5c..773b9e45806b 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -146,6 +146,10 @@ 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 bool imx6_pcie_cmp_mode; +module_param_named(compliance, imx6_pcie_cmp_mode, bool, 0644); +MODULE_PARM_DESC(compliance, "i.MX PCIe compliance test mode (1=compliance test mode enabled)"); + static int pcie_phy_poll_ack(struct imx6_pcie *imx6_pcie, bool exp_val) { struct dw_pcie *pci = imx6_pcie->pci; @@ -832,10 +836,12 @@ 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_mode) { + 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); @@ -924,18 +930,20 @@ static void imx6_pcie_host_exit(struct pcie_port *pp) struct device *dev = pci->dev; struct imx6_pcie *imx6_pcie = to_imx6_pcie(pci); - imx6_pcie_reset_phy(imx6_pcie); - imx6_pcie_clk_disable(imx6_pcie); - switch (imx6_pcie->drvdata->variant) { - case IMX8MM: - if (phy_power_off(imx6_pcie->phy)) - dev_err(dev, "unable to power off phy\n"); - break; - default: - break; + if (!imx6_pcie_cmp_mode) { + imx6_pcie_reset_phy(imx6_pcie); + imx6_pcie_clk_disable(imx6_pcie); + switch (imx6_pcie->drvdata->variant) { + case IMX8MM: + if (phy_power_off(imx6_pcie->phy)) + dev_err(dev, "unable to power off phy\n"); + break; + default: + break; + } + if (imx6_pcie->vpcie) + regulator_disable(imx6_pcie->vpcie); } - if (imx6_pcie->vpcie) - regulator_disable(imx6_pcie->vpcie); } static const struct dw_pcie_host_ops imx6_pcie_host_ops = { @@ -1250,8 +1258,15 @@ 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_mode) { + dev_info(dev, "Driver loaded with compliance test mode enabled.\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);