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Groups > linux.kernel > #1599427
| From | Kishon Vijay Abraham I <kishon@ti.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v4 14/23] PCI: dwc: dra7xx: Workaround for errata id i870 |
| Date | 2017-03-13 15:30 +0100 |
| Message-ID | <tkz8Z-1Mu-3@gated-at.bofh.it> (permalink) |
| References | <tkz8Z-1Mu-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
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 | 53 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)
diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index 35c18534469c..147d37a7fe58 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 +530,51 @@ 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 regmap *regmap;
+ unsigned int reg;
+ unsigned int field;
+
+ 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;
+ }
+
+ if (of_property_read_u32_index(np, "ti,syscon-unaligned-access", 1,
+ ®)) {
+ dev_err(dev, "couldn't get legacy mode register offset\n");
+ return -EINVAL;
+ }
+
+ if (of_property_read_u32_index(np, "ti,syscon-unaligned-access", 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 enable unaligned access\n");
+
+ return ret;
+}
+
static int __init dra7xx_pcie_probe(struct platform_device *pdev)
{
u32 reg;
@@ -637,6 +684,7 @@ 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;
@@ -644,6 +692,11 @@ 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
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[GIT PULL 00/23] PCI: Support for configurable PCI endpoint Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 16/23] PCI: Add device IDs for DRA74x and DRA72x Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 14/23] PCI: dwc: dra7xx: Workaround for errata id i870 Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 15/23] dt-bindings: PCI: dra7xx: Add dt bindings to enable unaligned access Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 07/23] PCI: endpoint: functions: Add an EP function to test PCI Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 19/23] tools: PCI: Add a userspace tool to test PCI endpoint Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 13/23] dt-bindings: PCI: dra7xx: Add dt bindings for pci dra7xx EP mode Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 09/23] PCI: dwc: designware: Add EP mode support Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 08/23] Documentation: PCI: Add binding documentation for pci-test endpoint function Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 23/23] ARM: DRA7: clockdomain: Change the CLKTRCTRL of CM_PCIE_CLKSTCTRL to SW_WKUP Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 17/23] misc: Add host side pci driver for pci test function device Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 22/23] MAINTAINERS: add PCI EP maintainer Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 18/23] Documentation: misc-devices: Add Documentation for pci-endpoint-test driver Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 20/23] tools: PCI: Add sample test script to invoke pcitest Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 12/23] PCI: dwc: dra7xx: Add EP mode support Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 21/23] Documentation: PCI: Add userguide for PCI endpoint test function Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 02/23] Documentation: PCI: Guide to use PCI Endpoint Core Layer Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:30 +0100 [PATCH v4 10/23] dt-bindings: PCI: Add dt bindings for pci designware EP mode Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:40 +0100 [PATCH v4 06/23] Documentation: PCI: Add specification for the *pci test* function device Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:40 +0100 [PATCH v4 11/23] PCI: dwc: dra7xx: Facilitate wrapper and msi interrupts to be enabled independently Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:40 +0100 [PATCH v4 04/23] Documentation: PCI: Guide to use pci endpoint configfs Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:40 +0100 [PATCH v4 03/23] PCI: endpoint: Introduce configfs entry for configuring EP functions Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:40 +0100 [PATCH v4 05/23] PCI: endpoint: Create configfs entry for EPC device and EPF driver Kishon Vijay Abraham I <kishon@ti.com> - 2017-03-13 15:40 +0100
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