Some PCIe ports gate power to the slot. In order to prevent system lockup,
these boards must enable power to the slot before attempting communication
over the PCI bus.
Signed-off-by: Sean Cross <xobs@xxxxxxxxxx>
---
.../devicetree/bindings/pci/fsl,imx6q-pcie.txt | 3 +++
drivers/pci/host/pci-imx6.c | 20 +++++++++++++++++++-
2 files changed, 22 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index 6fbba53..fe912bd 100644
--- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
@@ -13,6 +13,9 @@ Required properties:
- clock-names: Must include the following additional entries:
- "pcie_phy"
+Optional properties:
+- power-supply: A regulator that controls power to the port
+
Example:
pcie@0x01000000 {
diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c
index 69202d1..9c2140e 100644
--- a/drivers/pci/host/pci-imx6.c
+++ b/drivers/pci/host/pci-imx6.c
@@ -22,6 +22,7 @@
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
#include <linux/resource.h>
#include <linux/signal.h>
#include <linux/types.h>
@@ -39,6 +40,7 @@ struct imx6_pcie {
struct pcie_port pp;
struct regmap *iomuxc_gpr;
void __iomem *mem_base;
+ struct regulator *power_reg;
};
/* PCIe Root Complex registers (memory-mapped) */
@@ -588,6 +590,19 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
}
}
+ /* Fetch power supply */
+ imx6_pcie->power_reg = devm_regulator_get(&pdev->dev, "power");
+ if (IS_ERR(imx6_pcie->power_reg))
+ imx6_pcie->power_reg = 0;
+
+ if (imx6_pcie->power_reg) {
+ ret = regulator_enable(imx6_pcie->power_reg);
+ if (ret) {
+ dev_err(&pdev->dev, "Unable to enable power regulator");
+ return ret;
+ }
+ }
+
/* Fetch clocks */
imx6_pcie->pcie_phy = devm_clk_get(&pdev->dev, "pcie_phy");
if (IS_ERR(imx6_pcie->pcie_phy)) {
@@ -619,8 +634,11 @@ static int __init imx6_pcie_probe(struct platform_device *pdev)
}
ret = imx6_add_pcie_port(pp, pdev);
- if (ret < 0)
+ if (ret < 0) {
+ if (imx6_pcie->power_reg)
+ regulator_disable(imx6_pcie->power_reg);
return ret;
+ }
platform_set_drvdata(pdev, imx6_pcie);
return 0;
--
2.1.3
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