From 58ff463396ad00828e922d50998787e97fd32512 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Wed, 17 Feb 2010 23:36:58 +0100 Subject: PCI PM: Add function for checking PME status of devices Add function pci_check_pme_status() that will check the PME status bit of given device and clear it along with the PME enable bit. It will be necessary for PCI run-time power management. Based on a patch from Shaohua Li Signed-off-by: Rafael J. Wysocki Signed-off-by: Jesse Barnes --- drivers/pci/pci.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'drivers/pci/pci.c') diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 1f9be53c39ba..5723446544fd 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1194,6 +1194,41 @@ int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) return pcibios_set_pcie_reset_state(dev, state); } +/** + * pci_check_pme_status - Check if given device has generated PME. + * @dev: Device to check. + * + * Check the PME status of the device and if set, clear it and clear PME enable + * (if set). Return 'true' if PME status and PME enable were both set or + * 'false' otherwise. + */ +bool pci_check_pme_status(struct pci_dev *dev) +{ + int pmcsr_pos; + u16 pmcsr; + bool ret = false; + + if (!dev->pm_cap) + return false; + + pmcsr_pos = dev->pm_cap + PCI_PM_CTRL; + pci_read_config_word(dev, pmcsr_pos, &pmcsr); + if (!(pmcsr & PCI_PM_CTRL_PME_STATUS)) + return false; + + /* Clear PME status. */ + pmcsr |= PCI_PM_CTRL_PME_STATUS; + if (pmcsr & PCI_PM_CTRL_PME_ENABLE) { + /* Disable PME to avoid interrupt flood. */ + pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; + ret = true; + } + + pci_write_config_word(dev, pmcsr_pos, pmcsr); + + return ret; +} + /** * pci_pme_capable - check the capability of PCI device to generate PME# * @dev: PCI device to handle. -- cgit v1.2.3