PCI: brcmstb: Do not turn off WOL regulators on suspend

If any downstream device can be a wakeup device, do not turn off the
regulators as the device will need them on.

Link: https://lore.kernel.org/r/20220106160332.2143-8-jim2101024@gmail.com
Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index 5a7ee48..1cba6e6 100644 (file)
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -310,6 +310,7 @@ struct brcm_pcie {
        void                    (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val);
        bool                    refusal_mode;
        struct subdev_regulators *sr;
+       bool                    ep_wakeup_capable;
 };
 
 /*
@@ -1278,9 +1279,21 @@ static void brcm_pcie_turn_off(struct brcm_pcie *pcie)
        pcie->bridge_sw_init_set(pcie, 1);
 }
 
+static int pci_dev_may_wakeup(struct pci_dev *dev, void *data)
+{
+       bool *ret = data;
+
+       if (device_may_wakeup(&dev->dev)) {
+               *ret = true;
+               dev_info(&dev->dev, "disable cancelled for wake-up device\n");
+       }
+       return (int) *ret;
+}
+
 static int brcm_pcie_suspend(struct device *dev)
 {
        struct brcm_pcie *pcie = dev_get_drvdata(dev);
+       struct pci_host_bridge *bridge = pci_host_bridge_from_priv(pcie);
        int ret;
 
        brcm_pcie_turn_off(pcie);
@@ -1299,11 +1312,22 @@ static int brcm_pcie_suspend(struct device *dev)
        }
 
        if (pcie->sr) {
-               ret = regulator_bulk_disable(pcie->sr->num_supplies, pcie->sr->supplies);
-               if (ret) {
-                       dev_err(dev, "Could not turn off regulators\n");
-                       reset_control_reset(pcie->rescal);
-                       return ret;
+               /*
+                * Now turn off the regulators, but if at least one
+                * downstream device is enabled as a wake-up source, do not
+                * turn off regulators.
+                */
+               pcie->ep_wakeup_capable = false;
+               pci_walk_bus(bridge->bus, pci_dev_may_wakeup,
+                            &pcie->ep_wakeup_capable);
+               if (!pcie->ep_wakeup_capable) {
+                       ret = regulator_bulk_disable(pcie->sr->num_supplies,
+                                                    pcie->sr->supplies);
+                       if (ret) {
+                               dev_err(dev, "Could not turn off regulators\n");
+                               reset_control_reset(pcie->rescal);
+                               return ret;
+                       }
                }
        }
        clk_disable_unprepare(pcie->clk);
@@ -1324,10 +1348,21 @@ static int brcm_pcie_resume(struct device *dev)
                return ret;
 
        if (pcie->sr) {
-               ret = regulator_bulk_enable(pcie->sr->num_supplies, pcie->sr->supplies);
-               if (ret) {
-                       dev_err(dev, "Could not turn on regulators\n");
-                       goto err_disable_clk;
+               if (pcie->ep_wakeup_capable) {
+                       /*
+                        * We are resuming from a suspend.  In the suspend we
+                        * did not disable the power supplies, so there is
+                        * no need to enable them (and falsely increase their
+                        * usage count).
+                        */
+                       pcie->ep_wakeup_capable = false;
+               } else {
+                       ret = regulator_bulk_enable(pcie->sr->num_supplies,
+                                                   pcie->sr->supplies);
+                       if (ret) {
+                               dev_err(dev, "Could not turn on regulators\n");
+                               goto err_disable_clk;
+                       }
                }
        }