[PATCH V3 1/8] PCI: imx6: Add skip_pwrctrl_off flag support

[Sherry Sun (OSS)]

From: Sherry Sun <sherry.sun@xxxxxxx>

Use dw_pcie_rp::skip_pwrctrl_off to avoid powering off devices during
suspend to preserve wakeup capability of the devices and also not to power
on the devices in the init path.
This allows controller power-off to be skipped when some devices(e.g. M.2
cards key E without auxiliary power) required to support PCIe L2 link state
and wake-up mechanisms.

Move pci_pwrctrl_create_devices() to imx_pcie_probe() so that it is only
called once during probe, similar to other regulator_get calls.

Signed-off-by: Sherry Sun <sherry.sun@xxxxxxx>
---
 drivers/pci/controller/dwc/pci-imx6.c | 43 ++++++++++++++++-----------
 1 file changed, 25 insertions(+), 18 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 0fa716d1ed75..0685573fee71 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1382,16 +1382,12 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp)
 		}
 	}
 
-	ret = pci_pwrctrl_create_devices(dev);
-	if (ret) {
-		dev_err(dev, "failed to create pwrctrl devices\n");
-		goto err_reg_disable;
-	}
-
-	ret = pci_pwrctrl_power_on_devices(dev);
-	if (ret) {
-		dev_err(dev, "failed to power on pwrctrl devices\n");
-		goto err_pwrctrl_destroy;
+	if (!pp->skip_pwrctrl_off) {
+		ret = pci_pwrctrl_power_on_devices(dev);
+		if (ret) {
+			dev_err(dev, "failed to power on pwrctrl devices\n");
+			goto err_reg_disable;
+		}
 	}
 
 	ret = imx_pcie_clk_enable(imx_pcie);
@@ -1460,10 +1456,8 @@ static int imx_pcie_host_init(struct dw_pcie_rp *pp)
 err_clk_disable:
 	imx_pcie_clk_disable(imx_pcie);
 err_pwrctrl_power_off:
-	pci_pwrctrl_power_off_devices(dev);
-err_pwrctrl_destroy:
-	if (ret != -EPROBE_DEFER)
-		pci_pwrctrl_destroy_devices(dev);
+	if (!pp->skip_pwrctrl_off)
+		pci_pwrctrl_power_off_devices(dev);
 err_reg_disable:
 	if (imx_pcie->vpcie)
 		regulator_disable(imx_pcie->vpcie);
@@ -1482,7 +1476,8 @@ static void imx_pcie_host_exit(struct dw_pcie_rp *pp)
 	}
 	imx_pcie_clk_disable(imx_pcie);
 
-	pci_pwrctrl_power_off_devices(pci->dev);
+	if (!pci->pp.skip_pwrctrl_off)
+		pci_pwrctrl_power_off_devices(pci->dev);
 	if (imx_pcie->vpcie)
 		regulator_disable(imx_pcie->vpcie);
 }
@@ -1954,11 +1949,15 @@ static int imx_pcie_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = pci_pwrctrl_create_devices(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to create pwrctrl devices\n");
+
 	pci->use_parent_dt_ranges = true;
 	if (imx_pcie->drvdata->mode == DW_PCIE_EP_TYPE) {
 		ret = imx_add_pcie_ep(imx_pcie, pdev);
 		if (ret < 0)
-			return ret;
+			goto err_pwrctrl_destroy;
 
 		/*
 		 * FIXME: Only single Device (EPF) is supported due to the
@@ -1973,7 +1972,7 @@ static int imx_pcie_probe(struct platform_device *pdev)
 		pci->pp.use_atu_msg = true;
 		ret = dw_pcie_host_init(&pci->pp);
 		if (ret < 0)
-			return ret;
+			goto err_pwrctrl_destroy;
 
 		if (pci_msi_enabled()) {
 			u8 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_MSI);
@@ -1985,16 +1984,24 @@ static int imx_pcie_probe(struct platform_device *pdev)
 	}
 
 	return 0;
+
+err_pwrctrl_destroy:
+	if (ret != -EPROBE_DEFER)
+		pci_pwrctrl_destroy_devices(dev);
+	return ret;
 }
 
 static void imx_pcie_shutdown(struct platform_device *pdev)
 {
 	struct imx_pcie *imx_pcie = platform_get_drvdata(pdev);
+	struct dw_pcie *pci = imx_pcie->pci;
+	struct dw_pcie_rp *pp = &pci->pp;
 
 	/* bring down link, so bootloader gets clean state in case of reboot */
 	imx_pcie_assert_core_reset(imx_pcie);
 	imx_pcie_assert_perst(imx_pcie, true);
-	pci_pwrctrl_power_off_devices(&pdev->dev);
+	if (!pp->skip_pwrctrl_off)
+		pci_pwrctrl_power_off_devices(&pdev->dev);
 	pci_pwrctrl_destroy_devices(&pdev->dev);
 }
 
-- 
2.50.1