PCI: qcom: add runtime pm support to pcie_port

This patch is required when the pcie controller sits on a bus with
its own power domain and clocks which are controlled via a bus driver
like simple pm bus. As these bus driver have runtime pm enabled, it makes
sense to update the usage counter so that the runtime pm does not suspend
the clks or power domain associated with the bus driver.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Acked-by: Stanimir Varbanov <svarbanov@mm-sol.com>

drivers/pci/dwc/pcie-qcom.c

@@ -19,6 +19,7 @@
 #include <linux/of_device.h>
 #include <linux/of_gpio.h>
 #include <linux/pci.h>
+#include <linux/pm_runtime.h>
 #include <linux/platform_device.h>
 #include <linux/phy/phy.h>
 #include <linux/regulator/consumer.h>
@@ -1088,6 +1089,7 @@ static int qcom_pcie_host_init(struct pcie_port *pp)
 	struct qcom_pcie *pcie = to_qcom_pcie(pci);
 	int ret;
 
+	pm_runtime_get_sync(pci->dev);
 	qcom_ep_reset_assert(pcie);
 
 	ret = pcie->ops->init(pcie);
@@ -1124,6 +1126,7 @@ err_disable_phy:
 	phy_power_off(pcie->phy);
 err_deinit:
 	pcie->ops->deinit(pcie);
+	pm_runtime_put(pci->dev);
 
 	return ret;
 }
@@ -1212,6 +1215,7 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 	if (!pci)
 		return -ENOMEM;
 
+	pm_runtime_enable(dev);
 	pci->dev = dev;
 	pci->ops = &dw_pcie_ops;
 	pp = &pci->pp;
@@ -1257,14 +1261,17 @@ static int qcom_pcie_probe(struct platform_device *pdev)
 	}
 
 	ret = phy_init(pcie->phy);
-	if (ret)
+	if (ret) {
+		pm_runtime_disable(&pdev->dev);
 		return ret;
+	}
 
 	platform_set_drvdata(pdev, pcie);
 
 	ret = dw_pcie_host_init(pp);
 	if (ret) {
 		dev_err(dev, "cannot initialize host\n");
+		pm_runtime_disable(&pdev->dev);
 		return ret;
 	}