From patchwork Thu Jan 12 10:26:18 2017 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: 9512653 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7DDB160476 for ; Thu, 12 Jan 2017 10:31:41 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 718FF285F0 for ; Thu, 12 Jan 2017 10:31:41 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6623128681; Thu, 12 Jan 2017 10:31:41 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham 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 597BF285F0 for ; Thu, 12 Jan 2017 10:31:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752156AbdALKbj (ORCPT ); Thu, 12 Jan 2017 05:31:39 -0500 Received: from fllnx209.ext.ti.com ([198.47.19.16]:20120 "EHLO fllnx209.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751622AbdALKbe (ORCPT ); Thu, 12 Jan 2017 05:31:34 -0500 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by fllnx209.ext.ti.com (8.15.1/8.15.1) with ESMTP id v0CATX1p029182; Thu, 12 Jan 2017 04:29:33 -0600 Received: from DLEE71.ent.ti.com (dlee71.ent.ti.com [157.170.170.114]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id v0CATSep026026; Thu, 12 Jan 2017 04:29:28 -0600 Received: from dflp32.itg.ti.com (10.64.6.15) by DLEE71.ent.ti.com (157.170.170.114) with Microsoft SMTP Server id 14.3.294.0; Thu, 12 Jan 2017 04:29:27 -0600 Received: from a0393678ub.india.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id v0CAQpCe016300; Thu, 12 Jan 2017 04:29:21 -0600 From: Kishon Vijay Abraham I To: Bjorn Helgaas , Jingoo Han , Joao Pinto , Arnd Bergmann CC: , , , , , , , , , , , Subject: [PATCH 29/37] PCI: dwc: dra7xx: Workaround for errata id i870 Date: Thu, 12 Jan 2017 15:56:18 +0530 Message-ID: <1484216786-17292-30-git-send-email-kishon@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1484216786-17292-1-git-send-email-kishon@ti.com> References: <1484216786-17292-1-git-send-email-kishon@ti.com> MIME-Version: 1.0 Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP According to errata i870, access to the PCIe slave port that are not 32-bit aligned will result in incorrect mapping to TLP Address and Byte enable fields. Accessing non 32-bit aligned data causes incorrect data in the target buffer if memcpy is used. Implement the workaround for this errata here. Signed-off-by: Kishon Vijay Abraham I --- drivers/pci/dwc/pci-dra7xx.c | 50 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c index 333aa56..7666e3e 100644 --- a/drivers/pci/dwc/pci-dra7xx.c +++ b/drivers/pci/dwc/pci-dra7xx.c @@ -26,6 +26,8 @@ #include #include #include +#include +#include #include "pcie-designware.h" @@ -531,6 +533,48 @@ static int dra7xx_pcie_enable_phy(struct dra7xx_pcie *dra7xx) {}, }; +/* + * dra7xx_pcie_ep_legacy_mode: workaround for AM572x/AM571x Errata i870 + * @dra7xx: the dra7xx device where the workaround should be applied + * + * Access to the PCIe slave port that are not 32-bit aligned will result + * in incorrect mapping to TLP Address and Byte enable fields. Therefore, + * byte and half-word accesses are not possible to byte offset 0x1, 0x2, or + * 0x3. + * + * To avoid this issue set PCIE_SS1_AXI2OCP_LEGACY_MODE_ENABLE to 1. + */ +static int dra7xx_pcie_ep_legacy_mode(struct device *dev) +{ + int ret; + struct device_node *np = dev->of_node; + struct regmap *regmap; + unsigned int reg; + unsigned int field; + + regmap = syscon_regmap_lookup_by_phandle(np, "syscon-legacy-mode"); + if (IS_ERR(regmap)) { + dev_dbg(dev, "can't get syscon-legacy-mode\n"); + return -EINVAL; + } + + if (of_property_read_u32_index(np, "syscon-legacy-mode", 1, ®)) { + dev_err(dev, "couldn't get legacy mode register offset\n"); + return -EINVAL; + } + + if (of_property_read_u32_index(np, "syscon-legacy-mode", 2, &field)) { + dev_err(dev, "can't get bit field for setting legacy mode\n"); + return -EINVAL; + } + + ret = regmap_update_bits(regmap, reg, field, field); + if (ret) + dev_err(dev, "failed to set legacy mode\n"); + + return ret; +} + static int __init dra7xx_pcie_probe(struct platform_device *pdev) { u32 reg; @@ -643,6 +687,7 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev) case DW_PCIE_RC_TYPE: dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_DEVICE_TYPE, DEVICE_TYPE_RC); + ret = dra7xx_add_pcie_port(dra7xx, pdev); if (ret < 0) goto err_gpio; @@ -650,6 +695,11 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev) case DW_PCIE_EP_TYPE: dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_DEVICE_TYPE, DEVICE_TYPE_EP); + + ret = dra7xx_pcie_ep_legacy_mode(dev); + if (ret) + goto err_gpio; + ret = dra7xx_add_pcie_ep(dra7xx, pdev); if (ret < 0) goto err_gpio;