From patchwork Fri Feb 17 09:50:33 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: 94141 Delivered-To: patch@linaro.org Received: by 10.140.20.99 with SMTP id 90csp90236qgi; Fri, 17 Feb 2017 01:59:23 -0800 (PST) X-Received: by 10.99.140.28 with SMTP id m28mr9122295pgd.174.1487325563142; Fri, 17 Feb 2017 01:59:23 -0800 (PST) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id u67si9803214pfb.239.2017.02.17.01.59.22; Fri, 17 Feb 2017 01:59:23 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=ti.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934017AbdBQJ7V (ORCPT + 25 others); Fri, 17 Feb 2017 04:59:21 -0500 Received: from lelnx193.ext.ti.com ([198.47.27.77]:62142 "EHLO lelnx193.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933794AbdBQJwL (ORCPT ); Fri, 17 Feb 2017 04:52:11 -0500 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by lelnx193.ext.ti.com (8.15.1/8.15.1) with ESMTP id v1H9peUR015080; Fri, 17 Feb 2017 03:51:40 -0600 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id v1H9peHQ024925; Fri, 17 Feb 2017 03:51:40 -0600 Received: from dflp32.itg.ti.com (10.64.6.15) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.294.0; Fri, 17 Feb 2017 03:51:39 -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 v1H9omdS011603; Fri, 17 Feb 2017 03:51:37 -0600 From: Kishon Vijay Abraham I To: Bjorn Helgaas , Jingoo Han , Joao Pinto CC: , , , , , , , Kishon Vijay Abraham I Subject: [PATCH v2 13/22] PCI: dwc: dra7xx: Workaround for errata id i870 Date: Fri, 17 Feb 2017 15:20:33 +0530 Message-ID: <1487325042-28227-14-git-send-email-kishon@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1487325042-28227-1-git-send-email-kishon@ti.com> References: <1487325042-28227-1-git-send-email-kishon@ti.com> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(+) -- 1.7.9.5 diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c index 47bb563..df11a49 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" @@ -528,6 +530,48 @@ 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; @@ -644,6 +688,7 @@ 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; @@ -651,6 +696,11 @@ 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;