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 X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 7EF9AC433E0 for ; Tue, 23 Jun 2020 21:36:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 581D72078E for ; Tue, 23 Jun 2020 21:36:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592948173; bh=oI11+UeCNAjXbuWH90HC9sblP0vXUeNVYXJNIZhvkVM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NqM+lqEdB/EmYpQjmPTTe2easxZPqgPyW0T5cnuf6e+LGjizPgqI2zylU5faL/5Gg sBF2iOZimjylixlKxBwfvcUMcWUIwAXdrHxPbdwoRNLO49UYoCo5YxN8bUbvSZiPkS iYgbpYD0j6TJvB9zRfTz/q+9Pwi3SX7a2HDbz4+w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388307AbgFWVgL (ORCPT ); Tue, 23 Jun 2020 17:36:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:51200 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388396AbgFWUKD (ORCPT ); Tue, 23 Jun 2020 16:10:03 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 15A8720EDD; Tue, 23 Jun 2020 20:10:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592943002; bh=oI11+UeCNAjXbuWH90HC9sblP0vXUeNVYXJNIZhvkVM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=x5EDxhkI9Awk1MZTGFrB8cRmL3ppnjyJS/N0K+RdqlvhJzryuSX02dR84c7uaCEwO g2lSZhJ6hcQ5W9pHtM7oLDsUJZUeNXnRQFtZaOs/7B5qjlPksCFlGr5e9sjyKPB6Pk yH2l/ZPPHxEpg5kaSBBY3GeNwexXnEke8RL+BwwM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tomasz Maciej Nowak , =?UTF-8?q?Pali=20Roh=C3=A1r?= , Lorenzo Pieralisi , Thomas Petazzoni , Sasha Levin Subject: [PATCH 5.7 220/477] PCI: aardvark: Issue PERST via GPIO Date: Tue, 23 Jun 2020 21:53:37 +0200 Message-Id: <20200623195417.984616032@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200623195407.572062007@linuxfoundation.org> References: <20200623195407.572062007@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pali Rohár [ Upstream commit 5169a9851daaa2782a7bd2bb83d5b1bd224b2879 ] Add support for issuing PERST via GPIO specified in 'reset-gpios' property (as described in PCI device tree bindings). Some buggy cards (e.g. Compex WLE900VX or WLE1216) are not detected after reboot when PERST is not issued during driver initialization. If bootloader already enabled link training then issuing PERST has no effect for some buggy cards (e.g. Compex WLE900VX) and these cards are not detected. We therefore clear the LINK_TRAINING_EN register before. It was observed that Compex WLE900VX card needs to be in PERST reset for at least 10ms if bootloader enabled link training. Tested on Turris MOX. Link: https://lore.kernel.org/r/20200430080625.26070-6-pali@kernel.org Tested-by: Tomasz Maciej Nowak Signed-off-by: Pali Rohár Signed-off-by: Lorenzo Pieralisi Acked-by: Thomas Petazzoni Signed-off-by: Sasha Levin --- drivers/pci/controller/pci-aardvark.c | 43 ++++++++++++++++++++++++++- 1 file changed, 42 insertions(+), 1 deletion(-) diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index e202f954eb84e..2ecc79c03ade1 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -9,6 +9,7 @@ */ #include +#include #include #include #include @@ -18,6 +19,7 @@ #include #include #include +#include #include #include "../pci.h" @@ -204,6 +206,7 @@ struct advk_pcie { int root_bus_nr; int link_gen; struct pci_bridge_emul bridge; + struct gpio_desc *reset_gpio; }; static inline void advk_writel(struct advk_pcie *pcie, u32 val, u64 reg) @@ -330,10 +333,31 @@ err: dev_err(dev, "link never came up\n"); } +static void advk_pcie_issue_perst(struct advk_pcie *pcie) +{ + u32 reg; + + if (!pcie->reset_gpio) + return; + + /* PERST does not work for some cards when link training is enabled */ + reg = advk_readl(pcie, PCIE_CORE_CTRL0_REG); + reg &= ~LINK_TRAINING_EN; + advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG); + + /* 10ms delay is needed for some cards */ + dev_info(&pcie->pdev->dev, "issuing PERST via reset GPIO for 10ms\n"); + gpiod_set_value_cansleep(pcie->reset_gpio, 1); + usleep_range(10000, 11000); + gpiod_set_value_cansleep(pcie->reset_gpio, 0); +} + static void advk_pcie_setup_hw(struct advk_pcie *pcie) { u32 reg; + advk_pcie_issue_perst(pcie); + /* Set to Direct mode */ reg = advk_readl(pcie, CTRL_CONFIG_REG); reg &= ~(CTRL_MODE_MASK << CTRL_MODE_SHIFT); @@ -406,7 +430,8 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) /* * PERST# signal could have been asserted by pinctrl subsystem before - * probe() callback has been called, making the endpoint going into + * probe() callback has been called or issued explicitly by reset gpio + * function advk_pcie_issue_perst(), making the endpoint going into * fundamental reset. As required by PCI Express spec a delay for at * least 100ms after such a reset before link training is needed. */ @@ -1046,6 +1071,22 @@ static int advk_pcie_probe(struct platform_device *pdev) } pcie->root_bus_nr = bus->start; + pcie->reset_gpio = devm_gpiod_get_from_of_node(dev, dev->of_node, + "reset-gpios", 0, + GPIOD_OUT_LOW, + "pcie1-reset"); + ret = PTR_ERR_OR_ZERO(pcie->reset_gpio); + if (ret) { + if (ret == -ENOENT) { + pcie->reset_gpio = NULL; + } else { + if (ret != -EPROBE_DEFER) + dev_err(dev, "Failed to get reset-gpio: %i\n", + ret); + return ret; + } + } + ret = of_pci_get_max_link_speed(dev->of_node); if (ret <= 0 || ret > 3) pcie->link_gen = 3; -- 2.25.1