From mboxrd@z Thu Jan 1 00:00:00 1970 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 52735C4332F for ; Fri, 6 May 2022 01:59:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1388212AbiEFCC4 (ORCPT ); Thu, 5 May 2022 22:02:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1388231AbiEFCCy (ORCPT ); Thu, 5 May 2022 22:02:54 -0400 Received: from inva020.nxp.com (inva020.nxp.com [92.121.34.13]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DC63F13D10; Thu, 5 May 2022 18:59:12 -0700 (PDT) Received: from inva020.nxp.com (localhost [127.0.0.1]) by inva020.eu-rdc02.nxp.com (Postfix) with ESMTP id 91A2F1A09D0; Fri, 6 May 2022 03:59:11 +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 2E2C31A0A37; Fri, 6 May 2022 03:59:11 +0200 (CEST) Received: from localhost.localdomain (shlinux2.ap.freescale.net [10.192.224.44]) by aprdc01srsp001v.ap-rdc01.nxp.com (Postfix) with ESMTP id 7C43C180031B; Fri, 6 May 2022 09:59:09 +0800 (+08) From: Richard Zhu To: l.stach@pengutronix.de, bhelgaas@google.com, robh+dt@kernel.org, broonie@kernel.org, lorenzo.pieralisi@arm.com, jingoohan1@gmail.com, festevam@gmail.com, francesco.dolcini@toradex.com Cc: hongxing.zhu@nxp.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de, linux-imx@nxp.com Subject: [PATCH v9 8/8] PCI: imx6: Add compliance tests mode support Date: Fri, 6 May 2022 09:47:09 +0800 Message-Id: <1651801629-30223-9-git-send-email-hongxing.zhu@nxp.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1651801629-30223-1-git-send-email-hongxing.zhu@nxp.com> References: <1651801629-30223-1-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 Chapter 3.2 System Board Signal Quality of PCI Express Architecture PHY Test Specification Revision 2.0. Signal quality tests (for example: jitter, differential eye opening and so on) can be executed with devices in the polling.compliance state. To let the device support polling.compliance state, the clocks and powers shouldn't be turned off when the probe of device driver fails. 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 | 39 ++++++++++++++++++--------- 1 file changed, 27 insertions(+), 12 deletions(-) diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index f0ffd9011975..f78b59822626 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; @@ -826,10 +830,12 @@ 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); @@ -887,14 +893,16 @@ static int imx6_pcie_start_link(struct dw_pcie *pci) dev_dbg(dev, "PHY DEBUG_R0=0x%08x DEBUG_R1=0x%08x\n", 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->phy != NULL) { - phy_power_off(imx6_pcie->phy); - phy_exit(imx6_pcie->phy); + if (!imx6_pcie_cmp_mode) { + imx6_pcie_reset_phy(imx6_pcie); + imx6_pcie_clk_disable(imx6_pcie); + if (imx6_pcie->phy != NULL) { + phy_power_off(imx6_pcie->phy); + phy_exit(imx6_pcie->phy); + } + if (imx6_pcie->vpcie) + regulator_disable(imx6_pcie->vpcie); } - if (imx6_pcie->vpcie) - regulator_disable(imx6_pcie->vpcie); return ret; } @@ -1289,8 +1297,15 @@ 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); -- 2.25.1