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[PATCH 29/37] PCI: dwc: dra7xx: Workaround for errata id i870

From Kishon Vijay Abraham I <kishon@ti.com>
Newsgroups linux.kernel
Subject [PATCH 29/37] PCI: dwc: dra7xx: Workaround for errata id i870
Date 2017-01-12 11:40 +0100
Message-ID <sYKXv-2QD-5@gated-at.bofh.it> (permalink)
References <sYKNQ-2Nu-3@gated-at.bofh.it>
Organization linux.* mail to news gateway

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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 |   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 <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"
 
@@ -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, &reg)) {
+		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;
-- 
1.7.9.5

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Thread

[PATCH 00/37] PCI: Support for configurable PCI endpoint Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:30 +0100
  [PATCH 23/37] PCI: dwc: Add *ops* to start and stop pcie link Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:30 +0100
  [PATCH 26/37] PCI: dwc: dra7xx: Facilitate wrapper and msi interrupts to be enabled independently Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 32/37] Documentation: misc-devices: Add Documentation for pci-endpoint-test driver Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 09/37] PCI: dwc: designware: Parse *num-lanes* property in dw_pcie_setup_rc Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
    Re: [PATCH 09/37] PCI: dwc: designware: Parse *num-lanes* property in  dw_pcie_setup_rc Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-13 18:30 +0100
      Re: [PATCH 09/37] PCI: dwc: designware: Parse *num-lanes* property in  dw_pcie_setup_rc Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-16 06:30 +0100
        Re: [PATCH 09/37] PCI: dwc: designware: Parse *num-lanes* property in  dw_pcie_setup_rc Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-16 11:30 +0100
  [PATCH 29/37] PCI: dwc: dra7xx: Workaround for errata id i870 Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 07/37] PCI: dwc: designware: Get device pointer at the start of dw_pcie_host_init Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
    Re: [PATCH 07/37] PCI: dwc: designware: Get device pointer at the  start of dw_pcie_host_init Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-13 18:30 +0100
  [PATCH 20/37] Documentation: PCI: Add binding documentation for pci-test endpoint function Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 33/37] tools: PCI: Add a userspace tool to test PCI endpoint Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 35/37] MAINTAINERS: add PCI EP maintainer Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 37/37] ARM: dts: DRA7: Add pcie1 dt node for EP mode Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 30/37] dt-bindings: PCI: dra7xx: Add dt bindings to enable legacy mode Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 17/37] Documentation: PCI: Guide to use pci endpoint configfs Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 34/37] tools: PCI: Add sample test script to invoke pcitest Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 22/37] PCI: dwc: Modify dbi accessors to access data of 4/2/1 bytes Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 15/37] Documentation: PCI: Guide to use PCI Endpoint Core Layer Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 36/37] ARM: DRA7: clockdomain: Change the CLKTRCTRL of CM_PCIE_CLKSTCTRL to SW_WKUP Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
    Re: [PATCH 36/37] ARM: DRA7: clockdomain: Change the CLKTRCTRL of  CM_PCIE_CLKSTCTRL to SW_WKUP Tony Lindgren <tony@atomide.com> - 2017-01-13 18:20 +0100
      Re: [PATCH 36/37] ARM: DRA7: clockdomain: Change the CLKTRCTRL of  CM_PCIE_CLKSTCTRL to SW_WKUP Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-16 07:10 +0100
  [PATCH 05/37] PCI: dwc: Add platform_set_drvdata Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
    Re: [PATCH 05/37] PCI: dwc: Add platform_set_drvdata Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-13 18:20 +0100
  [PATCH 19/37] PCI: endpoint: functions: Add an EP function to test PCI Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 18/37] Documentation: PCI: Add specification for the *pci test* function device Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 25/37] dt-bindings: PCI: Add dt bindings for pci designware EP mode Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 27/37] PCI: dwc: dra7xx: Add EP mode support Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 28/37] dt-bindings: PCI: dra7xx: Add dt bindings for pci dra7xx EP mode Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 31/37] misc: Add host side pci driver for pci test function device Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 24/37] PCI: dwc: designware: Add EP mode support Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 21/37] PCI: dwc: Modify dbi accessors to take dbi_base as argument Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:40 +0100
  [PATCH 10/37] PCI: dwc: designware: Fix style errors in pcie-designware.c Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:50 +0100
    Re: [PATCH 10/37] PCI: dwc: designware: Fix style errors in  pcie-designware.c Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-13 17:50 +0100
  [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and core  files Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:50 +0100
    Re: [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and  core files Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-13 18:00 +0100
      Re: [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and  core files Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-16 06:30 +0100
        Re: [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and  core files Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-16 11:30 +0100
          Re: [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and  core files Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-16 12:40 +0100
            Re: [PATCH 11/37] PCI: dwc: Split pcie-designware.c into host and  core files Joao Pinto <Joao.Pinto@synopsys.com> - 2017-01-16 14:40 +0100
  [PATCH 03/37] PCI: dwc: dra7xx: Populate cpu_addr_fixup ops Kishon Vijay Abraham I <kishon@ti.com> - 2017-01-12 11:50 +0100

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