From 494f319be78dc08c72d58cdd94bf09213b48238c Mon Sep 17 00:00:00 2001 From: Furquan Shaikh Date: Sat, 3 Oct 2020 16:23:55 -0700 Subject: [PATCH] pci_device: Add a helper function for determining if PCI device is wake source This change adds a helper function `pci_dev_is_wake_source()` that checks PME_STATUS and PME_ENABLE bits in PM control and status register to determine if the given device is the source of wake. BUG=b:169802515 BRANCH=zork Change-Id: I06e9530b568543ab2f05a4f38dc5c3a527ff391e Signed-off-by: Furquan Shaikh Reviewed-on: https://review.coreboot.org/c/coreboot/+/46030 Tested-by: build bot (Jenkins) Reviewed-by: Rob Barnes Reviewed-by: Tim Wawrzynczak --- src/device/pci_device.c | 18 ++++++++++++++++++ src/include/device/pci.h | 8 ++++++++ 2 files changed, 26 insertions(+) diff --git a/src/device/pci_device.c b/src/device/pci_device.c index 8a6f123969..ce3e50967a 100644 --- a/src/device/pci_device.c +++ b/src/device/pci_device.c @@ -1643,3 +1643,21 @@ void pci_dev_disable_bus_master(const struct device *dev) pci_update_config16(dev, PCI_COMMAND, ~PCI_COMMAND_MASTER, 0x0); } #endif + +bool pci_dev_is_wake_source(const struct device *dev) +{ + unsigned int pm_cap; + uint16_t pmcs; + + if (dev->path.type != DEVICE_PATH_PCI) + return false; + + pm_cap = pci_find_capability(dev, PCI_CAP_ID_PM); + if (!pm_cap) + return false; + + pmcs = pci_read_config16(dev, pm_cap + PCI_PM_CTRL); + + /* PCI Device is a wake source if PME_ENABLE and PME_STATUS are set in PMCS register. */ + return (pmcs & PCI_PM_CTRL_PME_ENABLE) && (pmcs & PCI_PM_CTRL_PME_STATUS); +} diff --git a/src/include/device/pci.h b/src/include/device/pci.h index 6e28cb7f64..58f5904996 100644 --- a/src/include/device/pci.h +++ b/src/include/device/pci.h @@ -80,6 +80,14 @@ void pci_bus_reset(struct bus *bus); struct device *pci_probe_dev(struct device *dev, struct bus *bus, unsigned int devfn); +/* + * Determine if the given PCI device is the source of wake from sleep by checking PME_STATUS and + * PME_ENABLE bits in PM control and status register. + * + * Returns true if PCI device is wake source, false otherwise. + */ +bool pci_dev_is_wake_source(const struct device *dev); + void do_pci_scan_bridge(struct device *dev, void (*do_scan_bus)(struct bus *bus, unsigned int min_devfn, unsigned int max_devfn));