From: kishon@ti.com (Kishon Vijay Abraham I)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v5 15/24] PCI: dwc: dra7xx: Workaround for errata id i870
Date: Mon, 27 Mar 2017 15:15:11 +0530 [thread overview]
Message-ID: <20170327094520.3129-16-kishon@ti.com> (raw)
In-Reply-To: <20170327094520.3129-1-kishon@ti.com>
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 <kishon@ti.com>
---
drivers/pci/dwc/pci-dra7xx.c | 47 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index 35c18534469c..79fb213e4877 100644
--- a/drivers/pci/dwc/pci-dra7xx.c
+++ b/drivers/pci/dwc/pci-dra7xx.c
@@ -26,6 +26,8 @@
#include <linux/pm_runtime.h>
#include <linux/resource.h>
#include <linux/types.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
#include "pcie-designware.h"
@@ -528,6 +530,46 @@ static const struct of_device_id of_dra7xx_pcie_match[] = {
{},
};
+/*
+ * dra7xx_pcie_ep_unaligned_memaccess: 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_unaligned_memaccess(struct device *dev)
+{
+ int ret;
+ struct device_node *np = dev->of_node;
+ struct of_phandle_args args;
+ struct regmap *regmap;
+
+ regmap = syscon_regmap_lookup_by_phandle(np,
+ "ti,syscon-unaligned-access");
+ if (IS_ERR(regmap)) {
+ dev_dbg(dev, "can't get ti,syscon-unaligned-access\n");
+ return -EINVAL;
+ }
+
+ of_parse_phandle_with_args(np, "ti,syscon-unaligned-access",
+ "#syscon-cells", 0, &args);
+ if (args.args_count != 2) {
+ dev_err(dev, "does not conform to #syscon-cells\n");
+ return -EINVAL;
+ }
+
+ ret = regmap_update_bits(regmap, args.args[0], args.args[1],
+ args.args[1]);
+ if (ret)
+ dev_err(dev, "failed to enable unaligned access\n");
+
+ return ret;
+}
+
static int __init dra7xx_pcie_probe(struct platform_device *pdev)
{
u32 reg;
@@ -644,6 +686,11 @@ 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_unaligned_memaccess(dev);
+ if (ret)
+ goto err_gpio;
+
ret = dra7xx_add_pcie_ep(dra7xx, pdev);
if (ret < 0)
goto err_gpio;
--
2.11.0
next prev parent reply other threads:[~2017-03-27 9:45 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-27 9:44 [GIT PULL] PCI: Support for configurable PCI endpoint Kishon Vijay Abraham I
2017-03-27 9:44 ` [PATCH v5 01/24] PCI: endpoint: Add EP core layer to enable EP controller and EP functions Kishon Vijay Abraham I
2017-03-27 9:44 ` [PATCH v5 02/24] Documentation: PCI: Guide to use PCI Endpoint Core Layer Kishon Vijay Abraham I
2017-03-27 9:44 ` [PATCH v5 03/24] PCI: endpoint: Introduce configfs entry for configuring EP functions Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 04/24] Documentation: PCI: Guide to use pci endpoint configfs Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 05/24] PCI: endpoint: Create configfs entry for EPC device and EPF driver Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 06/24] Documentation: PCI: Add specification for the *pci test* function device Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 07/24] PCI: endpoint: functions: Add an EP function to test PCI Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 08/24] Documentation: PCI: Add binding documentation for pci-test endpoint function Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 09/24] PCI: dwc: designware: Add EP mode support Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 10/24] dt-bindings: PCI: Add dt bindings for pci designware EP mode Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 11/24] PCI: dwc: dra7xx: Facilitate wrapper and msi interrupts to be enabled independently Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 12/24] PCI: dwc: dra7xx: Add EP mode support Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 13/24] dt-bindings: PCI: dra7xx: Add dt bindings for pci dra7xx EP mode Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 14/24] dt-bindings: mfd: syscon: Add documentation for #syscon-cells property Kishon Vijay Abraham I
2017-03-31 18:58 ` Rob Herring
2017-03-31 19:06 ` Rob Herring
2017-04-05 8:25 ` Kishon Vijay Abraham I
2017-03-27 9:45 ` Kishon Vijay Abraham I [this message]
2017-03-27 9:45 ` [PATCH v5 16/24] dt-bindings: PCI: dra7xx: Add dt bindings to enable unaligned access Kishon Vijay Abraham I
2017-03-31 19:07 ` Rob Herring
2017-03-27 9:45 ` [PATCH v5 17/24] PCI: Add device IDs for DRA74x and DRA72x Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 18/24] misc: Add host side pci driver for pci test function device Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 19/24] Documentation: misc-devices: Add Documentation for pci-endpoint-test driver Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 20/24] tools: PCI: Add a userspace tool to test PCI endpoint Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 21/24] tools: PCI: Add sample test script to invoke pcitest Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 22/24] Documentation: PCI: Add userguide for PCI endpoint test function Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 23/24] MAINTAINERS: add PCI EP maintainer Kishon Vijay Abraham I
2017-03-27 9:45 ` [PATCH v5 24/24] ARM: DRA7: clockdomain: Change the CLKTRCTRL of CM_PCIE_CLKSTCTRL to SW_WKUP Kishon Vijay Abraham I
2017-03-29 11:42 ` [GIT PULL] PCI: Support for configurable PCI endpoint Niklas Cassel
2017-03-29 12:10 ` Kishon Vijay Abraham I
2017-03-29 12:36 ` Kishon Vijay Abraham I
2017-03-29 13:13 ` Niklas Cassel
2017-04-04 20:36 ` Bjorn Helgaas
2017-04-05 8:47 ` Kishon Vijay Abraham I
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