Some boards might require to control a regulator to power the PCIe port.
This adds support for an optional regulator defined in Device Tree
linked in the PCIe controller under `vpcie-supply`. If present, the
regulator will be disabled and then enabled as part of the PCIe host
initialization process and will be disabled when shutting down.
Signed-off-by: Quentin Schulz <quentin.sch...@free-electrons.com>
---
.../devicetree/bindings/pci/fsl,imx6q-pcie.txt | 4 +++
drivers/pci/dwc/pci-imx6.c | 34 +++++++++++++++++++++-
2 files changed, 37 insertions(+), 1 deletion(-)
diff --git a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
index e3d5680875b1..cf92d3ba5a26 100644
--- a/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/fsl,imx6q-pcie.txt
@@ -33,6 +33,10 @@ Optional properties:
- reset-gpio-active-high: If present then the reset sequence using the GPIO
specified in the "reset-gpio" property is reversed (H=reset state,
L=operation state).
+- vpcie-supply: Should specify the regulator in charge of PCIe port power.
+ The regulator will be enabled when initializing the PCIe host and
+ disabled either as part of the init process or when shutting down the
+ host.
Additional required properties for imx6sx-pcie:
- clock names: Must include the following additional entries:
diff --git a/drivers/pci/dwc/pci-imx6.c b/drivers/pci/dwc/pci-imx6.c
index 19a289b8cc94..f9b7500c9aff 100644
--- a/drivers/pci/dwc/pci-imx6.c
+++ b/drivers/pci/dwc/pci-imx6.c
@@ -24,6 +24,7 @@
#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>
@@ -59,6 +60,7 @@ struct imx6_pcie {
u32 tx_swing_full;
u32 tx_swing_low;
int link_gen;
+ struct regulator *vpcie;
};
/* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
@@ -310,6 +312,13 @@ static void imx6_pcie_assert_core_reset(struct imx6_pcie
*imx6_pcie)
IMX6Q_GPR1_PCIE_REF_CLK_EN, 0 << 16);
break;
}
+
+ if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
+ int ret = regulator_disable(imx6_pcie->vpcie);
+
+ if (ret)
+ pr_err("failed to disable vpcie regulator: %d\n", ret);
+ }
}
static int imx6_pcie_enable_ref_clk(struct imx6_pcie *imx6_pcie)
@@ -376,10 +385,19 @@ static void imx6_pcie_deassert_core_reset(struct
imx6_pcie *imx6_pcie)
struct device *dev = pci->dev;
int ret;
+ if (imx6_pcie->vpcie && !regulator_is_enabled(imx6_pcie->vpcie)) {
+ ret = regulator_enable(imx6_pcie->vpcie);
+ if (ret) {
+ dev_err(dev, "failed to enable vpcie regulator: %d\n",
+ ret);
+ return;
+ }
+ }
+
ret = clk_prepare_enable(imx6_pcie->pcie_phy);
if (ret) {
dev_err(dev, "unable to enable pcie_phy clock\n");
- return;
+ goto err_pcie_phy;
}
ret = clk_prepare_enable(imx6_pcie->pcie_bus);
@@ -439,6 +457,13 @@ static void imx6_pcie_deassert_core_reset(struct imx6_pcie
*imx6_pcie)
clk_disable_unprepare(imx6_pcie->pcie_bus);
err_pcie_bus:
clk_disable_unprepare(imx6_pcie->pcie_phy);
+err_pcie_phy:
+ if (imx6_pcie->vpcie && regulator_is_enabled(imx6_pcie->vpcie) > 0) {
+ ret = regulator_disable(imx6_pcie->vpcie);
+ if (ret)
+ dev_err(dev, "failed to disable vpcie regulator: %d\n",
+ ret);
+ }
}
static void imx6_pcie_init_phy(struct imx6_pcie *imx6_pcie)
@@ -802,6 +827,13 @@ static int imx6_pcie_probe(struct platform_device *pdev)
if (ret)
imx6_pcie->link_gen = 1;
+ imx6_pcie->vpcie = devm_regulator_get_optional(&pdev->dev, "vpcie");
+ if (IS_ERR(imx6_pcie->vpcie)) {
+ if (PTR_ERR(imx6_pcie->vpcie) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ imx6_pcie->vpcie = NULL;
+ }
+
platform_set_drvdata(pdev, imx6_pcie);
ret = imx6_add_pcie_port(imx6_pcie, pdev);
--
2.11.0
