From patchwork Tue Jun 4 13:14:57 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kishon Vijay Abraham I X-Patchwork-Id: 10975035 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 852CE2D49 for ; Tue, 4 Jun 2019 13:18:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 74B9D22A6F for ; Tue, 4 Jun 2019 13:18:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 684A728867; Tue, 4 Jun 2019 13:18:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0F61122A6F for ; Tue, 4 Jun 2019 13:18:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727631AbfFDNSE (ORCPT ); Tue, 4 Jun 2019 09:18:04 -0400 Received: from fllv0016.ext.ti.com ([198.47.19.142]:50382 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727265AbfFDNSE (ORCPT ); Tue, 4 Jun 2019 09:18:04 -0400 Received: from lelv0265.itg.ti.com ([10.180.67.224]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id x54DHktZ082389; Tue, 4 Jun 2019 08:17:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1559654266; bh=t0jA6IyzaKFpaRxG+xMzbQ3TeSZ/biJLiuqhdnBH3TQ=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=KZr/Yb1n2JCx1xdXk+5fWxz251JLI16pKngaDfG2QC6hGXVLV4i5gvy6cCgIsJMjP c4WNdd1kbTd+yYCRuS/k+h6OJjnmI4OPZi0H3EJWyU1J15IIwDqImxqx57wu5Udo9Z bvFpZC/srm1v2Mm4BAhsZsXo0/fnO3zxZwm++kmk= Received: from DLEE104.ent.ti.com (dlee104.ent.ti.com [157.170.170.34]) by lelv0265.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x54DHkn2042937 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 4 Jun 2019 08:17:46 -0500 Received: from DLEE107.ent.ti.com (157.170.170.37) by DLEE104.ent.ti.com (157.170.170.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Tue, 4 Jun 2019 08:17:46 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DLEE107.ent.ti.com (157.170.170.37) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Tue, 4 Jun 2019 08:17:46 -0500 Received: from a0393678ub.india.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id x54DGdGR098972; Tue, 4 Jun 2019 08:17:41 -0500 From: Kishon Vijay Abraham I To: Tom Joseph , Bjorn Helgaas , Rob Herring , Mark Rutland , Lorenzo Pieralisi , Arnd Bergmann , Gustavo Pimentel CC: Greg Kroah-Hartman , Frank Rowand , Jingoo Han , , , , , , , Kishon Vijay Abraham I Subject: [RFC PATCH 11/30] PCI: cadence: Add support to drive PERST# line using GPIO Date: Tue, 4 Jun 2019 18:44:57 +0530 Message-ID: <20190604131516.13596-12-kishon@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190604131516.13596-1-kishon@ti.com> References: <20190604131516.13596-1-kishon@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In platforms like TI's J721E EVM, the PERST# line is connected to a GPIO line and PERST# should be driven high to indicate the clocks are stable (As per Figure 2-10: Power Up of the PCIe CEM spec 3.0). Add support to make GPIO drive PERST# line. Signed-off-by: Kishon Vijay Abraham I --- drivers/pci/controller/pcie-cadence-host.c | 26 ++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/drivers/pci/controller/pcie-cadence-host.c b/drivers/pci/controller/pcie-cadence-host.c index 4ad8f2ece6e2..8b3b9827a8d6 100644 --- a/drivers/pci/controller/pcie-cadence-host.c +++ b/drivers/pci/controller/pcie-cadence-host.c @@ -3,6 +3,8 @@ // Cadence PCIe host controller driver. // Author: Cyrille Pitchen +#include +#include #include #include #include @@ -287,6 +289,7 @@ static int cdns_pcie_host_probe(struct platform_device *pdev) struct pci_host_bridge *bridge; struct list_head resources; struct cdns_pcie_rc *rc; + struct gpio_desc *gpiod; struct cdns_pcie *pcie; struct resource *res; int ret; @@ -349,13 +352,36 @@ static int cdns_pcie_host_probe(struct platform_device *pdev) dev_err(dev, "missing \"mem\"\n"); return -EINVAL; } + pcie->mem_res = res; + gpiod = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(gpiod)) { + ret = PTR_ERR(gpiod); + if (ret != -EPROBE_DEFER) + dev_err(dev, "Failed to get reset GPIO\n"); + return ret; + } + ret = cdns_pcie_init_phy(dev, pcie); if (ret) { dev_err(dev, "failed to init phy\n"); return ret; } + + /* + * "Power Sequencing and Reset Signal Timings" table in + * PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION, REV. 3.0 + * indicates PERST# should be deasserted after minimum of 100us + * once REFCLK is stable. The REFCLK to the connector in RC + * mode is selected while enabling the PHY. So deassert PERST# + * after 100 us. + */ + if (gpiod) { + usleep_range(100, 200); + gpiod_set_value_cansleep(gpiod, 1); + } + platform_set_drvdata(pdev, pcie); pm_runtime_enable(dev);