commit 58dfb24349e1d0aa6461d2b0f2811b46fe350280
author Shawn Guo <shawn.guo@linaro.org> Fri Mar 02 09:12:01 2018 +0800
committer Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Wed Mar 07 16:24:27 2018 +0000
tree 93ae2e1c48dfb25305d015c2745e269f804dc8be
parent db0c25f8aadad8f0be1c6986cf1dcf874d40d79b

PCI: histb: Add an optional regulator for PCIe port power control

The power supplies to PCIe port are often controlled by GPIO on some board
designs.  Let's add an optional regulator which can be backed by GPIO to
control the power.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>

drivers/pci/dwc/pcie-histb.c

diff --git a/drivers/pci/dwc/pcie-histb.c b/drivers/pci/dwc/pcie-histb.c
index 17ed604..4cef0a5 100644
--- a/drivers/pci/dwc/pcie-histb.c
+++ b/drivers/pci/dwc/pcie-histb.c
@@ -61,6 +61,7 @@ struct histb_pcie {
 	struct reset_control *bus_reset;
 	void __iomem *ctrl;
 	int reset_gpio;
+	struct regulator *vpcie;
 };
 
 static u32 histb_pcie_readl(struct histb_pcie *histb_pcie, u32 reg)
@@ -227,6 +228,9 @@ static void histb_pcie_host_disable(struct histb_pcie *hipcie)
 
 	if (gpio_is_valid(hipcie->reset_gpio))
 		gpio_set_value_cansleep(hipcie->reset_gpio, 0);
+
+	if (hipcie->vpcie)
+		regulator_disable(hipcie->vpcie);
 }
 
 static int histb_pcie_host_enable(struct pcie_port *pp)
@@ -237,6 +241,14 @@ static int histb_pcie_host_enable(struct pcie_port *pp)
 	int ret;
 
 	/* power on PCIe device if have */
+	if (hipcie->vpcie) {
+		ret = regulator_enable(hipcie->vpcie);
+		if (ret) {
+			dev_err(dev, "failed to enable regulator: %d\n", ret);
+			return ret;
+		}
+	}
+
 	if (gpio_is_valid(hipcie->reset_gpio))
 		gpio_set_value_cansleep(hipcie->reset_gpio, 1);
 
@@ -282,6 +294,8 @@ static int histb_pcie_host_enable(struct pcie_port *pp)
 err_sys_clk:
 	clk_disable_unprepare(hipcie->bus_clk);
 err_bus_clk:
+	if (hipcie->vpcie)
+		regulator_disable(hipcie->vpcie);
 
 	return ret;
 }
@@ -331,6 +345,13 @@ static int histb_pcie_probe(struct platform_device *pdev)
 		return PTR_ERR(pci->dbi_base);
 	}
 
+	hipcie->vpcie = devm_regulator_get_optional(dev, "vpcie");
+	if (IS_ERR(hipcie->vpcie)) {
+		if (PTR_ERR(hipcie->vpcie) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		hipcie->vpcie = NULL;
+	}
+
 	hipcie->reset_gpio = of_get_named_gpio_flags(np,
 				"reset-gpios", 0, &of_flags);
 	if (of_flags & OF_GPIO_ACTIVE_LOW)