diff options
| -rw-r--r-- | drivers/pci/pci.c | 83 | ||||
| -rw-r--r-- | include/linux/pci.h | 2 |
2 files changed, 85 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index a6b1b6f96ab..1b0ec45e993 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1147,6 +1147,87 @@ int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable) } /** + * pci_prepare_to_sleep - prepare PCI device for system-wide transition into + * a sleep state + * @dev: Device to handle. + * + * Choose the power state appropriate for the device depending on whether + * it can wake up the system and/or is power manageable by the platform + * (PCI_D3hot is the default) and put the device into that state. + */ +int pci_prepare_to_sleep(struct pci_dev *dev) +{ + pci_power_t target_state = PCI_D3hot; + int pm = pci_find_capability(dev, PCI_CAP_ID_PM); + int error; + + if (platform_pci_power_manageable(dev)) { + /* + * Call the platform to choose the target state of the device + * and enable wake-up from this state if supported. + */ + pci_power_t state = platform_pci_choose_state(dev); + + switch (state) { + case PCI_POWER_ERROR: + case PCI_UNKNOWN: + break; + case PCI_D1: + case PCI_D2: + if (pci_no_d1d2(dev)) + break; + default: + target_state = state; + pci_enable_wake(dev, target_state, true); + } + } else if (device_may_wakeup(&dev->dev)) { + /* + * Find the deepest state from which the device can generate + * wake-up events, make it the target state and enable device + * to generate PME#. + */ + u16 pmc; + + if (!pm) + return -EIO; + + pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc); + if (pmc & PCI_PM_CAP_PME_MASK) { + if (!(pmc & PCI_PM_CAP_PME_D3)) { + /* Device cannot generate PME# from D3_hot */ + if (pmc & PCI_PM_CAP_PME_D2) + target_state = PCI_D2; + else if (pmc & PCI_PM_CAP_PME_D1) + target_state = PCI_D1; + else + target_state = PCI_D0; + } + pci_pme_active(dev, pm, true); + } + } + + error = pci_set_power_state(dev, target_state); + + if (error) + pci_enable_wake(dev, target_state, false); + + return error; +} + +/** + * pci_back_from_sleep - turn PCI device on during system-wide transition into + * the working state a sleep state + * @dev: Device to handle. + * + * Disable device's sytem wake-up capability and put it into D0. + */ +int pci_back_from_sleep(struct pci_dev *dev) +{ + pci_enable_wake(dev, PCI_D0, false); + return pci_set_power_state(dev, PCI_D0); +} + +/** * pci_pm_init - Initialize PM functions of given PCI device * @dev: PCI device to handle. */ @@ -1853,5 +1934,7 @@ EXPORT_SYMBOL(pci_set_power_state); EXPORT_SYMBOL(pci_save_state); EXPORT_SYMBOL(pci_restore_state); EXPORT_SYMBOL(pci_enable_wake); +EXPORT_SYMBOL(pci_prepare_to_sleep); +EXPORT_SYMBOL(pci_back_from_sleep); EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); diff --git a/include/linux/pci.h b/include/linux/pci.h index 4c80dc3f299..52ac06dcce9 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -632,6 +632,8 @@ int pci_restore_state(struct pci_dev *dev); int pci_set_power_state(struct pci_dev *dev, pci_power_t state); pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state); int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable); +int pci_prepare_to_sleep(struct pci_dev *dev); +int pci_back_from_sleep(struct pci_dev *dev); /* Functions for PCI Hotplug drivers to use */ int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap); |