From 7a32e9b3ff01cdc12ea124fa258aacd31490dd11 Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Mon, 25 Jul 2022 11:12:54 -0400 Subject: [PATCH] PCI: brcmstb: Disable/enable regulators in suspend/resume If we found power regulators for a device below the Root Port, disable them during suspend and re-enable them during resume. If any downstream device can be a wakeup device, do not turn off the regulators as the device will need them on. [bhelgaas: drop unused regulator_oops, skip wrapping of .add_bus()/ .remove_bus(), move brcm_pcie_start_link() to .add_bus() in previous patch, squash WOL checking into this patch] Link: https://lore.kernel.org/r/20220725151258.42574-6-jim2101024@gmail.com Link: https://lore.kernel.org/r/20220725151258.42574-7-jim2101024@gmail.com Signed-off-by: Jim Quinlan Signed-off-by: Bjorn Helgaas Tested-by: Florian Fainelli --- drivers/pci/controller/pcie-brcmstb.c | 64 ++++++++++++++++++++++++--- 1 file changed, 59 insertions(+), 5 deletions(-) diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c index 3092e262f07b..23b44a88be1b 100644 --- a/drivers/pci/controller/pcie-brcmstb.c +++ b/drivers/pci/controller/pcie-brcmstb.c @@ -262,6 +262,7 @@ struct brcm_pcie { void (*perst_set)(struct brcm_pcie *pcie, u32 val); void (*bridge_sw_init_set)(struct brcm_pcie *pcie, u32 val); struct subdev_regulators *sr; + bool ep_wakeup_capable; }; static inline bool is_bmips(const struct brcm_pcie *pcie) @@ -1244,9 +1245,21 @@ static void brcm_pcie_turn_off(struct brcm_pcie *pcie) pcie->bridge_sw_init_set(pcie, 1); } -static int brcm_pcie_suspend(struct device *dev) +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, "Possible wake-up device; regulators will not be disabled\n"); + } + return (int) *ret; +} + +static int brcm_pcie_suspend_noirq(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); @@ -1264,12 +1277,31 @@ static int brcm_pcie_suspend(struct device *dev) return ret; } + if (pcie->sr) { + /* + * 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); return 0; } -static int brcm_pcie_resume(struct device *dev) +static int brcm_pcie_resume_noirq(struct device *dev) { struct brcm_pcie *pcie = dev_get_drvdata(dev); void __iomem *base; @@ -1304,15 +1336,37 @@ static int brcm_pcie_resume(struct device *dev) if (ret) goto err_reset; + if (pcie->sr) { + 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_reset; + } + } + } + ret = brcm_pcie_start_link(pcie); if (ret) - goto err_reset; + goto err_regulator; if (pcie->msi) brcm_msi_set_regs(pcie->msi); return 0; +err_regulator: + if (pcie->sr) + regulator_bulk_disable(pcie->sr->num_supplies, pcie->sr->supplies); err_reset: reset_control_rearm(pcie->rescal); err_disable_clk: @@ -1541,8 +1595,8 @@ fail: MODULE_DEVICE_TABLE(of, brcm_pcie_match); static const struct dev_pm_ops brcm_pcie_pm_ops = { - .suspend = brcm_pcie_suspend, - .resume = brcm_pcie_resume, + .suspend_noirq = brcm_pcie_suspend_noirq, + .resume_noirq = brcm_pcie_resume_noirq, }; static struct platform_driver brcm_pcie_driver = {