diff options
Diffstat (limited to 'drivers/pci/pci.c')
| -rw-r--r-- | drivers/pci/pci.c | 150 |
1 files changed, 104 insertions, 46 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index f8074525267..20e28077b96 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -404,67 +404,56 @@ static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev) } /** - * pci_set_power_state - Set the power state of a PCI device - * @dev: PCI device to be suspended - * @state: PCI power state (D0, D1, D2, D3hot, D3cold) we're entering + * pci_raw_set_power_state - Use PCI PM registers to set the power state of + * given PCI device + * @dev: PCI device to handle. + * @pm: PCI PM capability offset of the device. + * @state: PCI power state (D0, D1, D2, D3hot) to put the device into. * - * Transition a device to a new power state, using the Power Management - * Capabilities in the device's config space. - * - * RETURN VALUE: - * -EINVAL if trying to enter a lower state than we're already in. - * 0 if we're already in the requested state. - * -EIO if device does not support PCI PM. - * 0 if we can successfully change the power state. + * RETURN VALUE: + * -EINVAL if the requested state is invalid. + * -EIO if device does not support PCI PM or its PM capabilities register has a + * wrong version, or device doesn't support the requested state. + * 0 if device already is in the requested state. + * 0 if device's power state has been successfully changed. */ -int -pci_set_power_state(struct pci_dev *dev, pci_power_t state) +static int +pci_raw_set_power_state(struct pci_dev *dev, int pm, pci_power_t state) { - int pm, need_restore = 0; u16 pmcsr, pmc; + bool need_restore = false; - /* bound the state we're entering */ - if (state > PCI_D3hot) - state = PCI_D3hot; - - /* - * If the device or the parent bridge can't support PCI PM, ignore - * the request if we're doing anything besides putting it into D0 - * (which would only happen on boot). - */ - if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev)) - return 0; - - /* find PCI PM capability in list */ - pm = pci_find_capability(dev, PCI_CAP_ID_PM); - - /* abort if the device doesn't support PM capabilities */ if (!pm) return -EIO; + if (state < PCI_D0 || state > PCI_D3hot) + return -EINVAL; + /* Validate current state: * Can enter D0 from any state, but if we can only go deeper * to sleep if we're already in a low power state */ - if (state != PCI_D0 && dev->current_state > state) { + if (dev->current_state == state) { + /* we're already there */ + return 0; + } else if (state != PCI_D0 && dev->current_state <= PCI_D3cold + && dev->current_state > state) { dev_err(&dev->dev, "invalid power transition " "(from state %d to %d)\n", dev->current_state, state); return -EINVAL; - } else if (dev->current_state == state) - return 0; /* we're already there */ + } + pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc); - pci_read_config_word(dev,pm + PCI_PM_PMC,&pmc); if ((pmc & PCI_PM_CAP_VER_MASK) > 3) { - dev_printk(KERN_DEBUG, &dev->dev, "unsupported PM cap regs " - "version (%u)\n", pmc & PCI_PM_CAP_VER_MASK); + dev_err(&dev->dev, "unsupported PM cap regs version (%u)\n", + pmc & PCI_PM_CAP_VER_MASK); return -EIO; } /* check if this device supports the desired state */ - if (state == PCI_D1 && !(pmc & PCI_PM_CAP_D1)) - return -EIO; - else if (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2)) + if ((state == PCI_D1 && !(pmc & PCI_PM_CAP_D1)) + || (state == PCI_D2 && !(pmc & PCI_PM_CAP_D2))) return -EIO; pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr); @@ -483,7 +472,7 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state) case PCI_UNKNOWN: /* Boot-up */ if ((pmcsr & PCI_PM_CTRL_STATE_MASK) == PCI_D3hot && !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET)) - need_restore = 1; + need_restore = true; /* Fall-through: force to D0 */ default: pmcsr = 0; @@ -500,12 +489,6 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state) else if (state == PCI_D2 || dev->current_state == PCI_D2) udelay(200); - /* - * Give firmware a chance to be called, such as ACPI _PRx, _PSx - * Firmware method after native method ? - */ - platform_pci_set_power_state(dev, state); - dev->current_state = state; /* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT @@ -530,6 +513,81 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state) } /** + * pci_update_current_state - Read PCI power state of given device from its + * PCI PM registers and cache it + * @dev: PCI device to handle. + * @pm: PCI PM capability offset of the device. + */ +static void pci_update_current_state(struct pci_dev *dev, int pm) +{ + if (pm) { + u16 pmcsr; + + pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr); + dev->current_state = (pmcsr & PCI_PM_CTRL_STATE_MASK); + } +} + +/** + * pci_set_power_state - Set the power state of a PCI device + * @dev: PCI device to handle. + * @state: PCI power state (D0, D1, D2, D3hot) to put the device into. + * + * Transition a device to a new power state, using the platform formware and/or + * the device's PCI PM registers. + * + * RETURN VALUE: + * -EINVAL if the requested state is invalid. + * -EIO if device does not support PCI PM or its PM capabilities register has a + * wrong version, or device doesn't support the requested state. + * 0 if device already is in the requested state. + * 0 if device's power state has been successfully changed. + */ +int pci_set_power_state(struct pci_dev *dev, pci_power_t state) +{ + int pm, error; + + /* bound the state we're entering */ + if (state > PCI_D3hot) + state = PCI_D3hot; + else if (state < PCI_D0) + state = PCI_D0; + else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev)) + /* + * If the device or the parent bridge do not support PCI PM, + * ignore the request if we're doing anything other than putting + * it into D0 (which would only happen on boot). + */ + return 0; + + /* Find PCI PM capability in the list */ + pm = pci_find_capability(dev, PCI_CAP_ID_PM); + + if (state == PCI_D0 && platform_pci_power_manageable(dev)) { + /* + * Allow the platform to change the state, for example via ACPI + * _PR0, _PS0 and some such, but do not trust it. + */ + int ret = platform_pci_set_power_state(dev, PCI_D0); + if (!ret) + pci_update_current_state(dev, pm); + } + + error = pci_raw_set_power_state(dev, pm, state); + + if (state > PCI_D0 && platform_pci_power_manageable(dev)) { + /* Allow the platform to finalize the transition */ + int ret = platform_pci_set_power_state(dev, state); + if (!ret) { + pci_update_current_state(dev, pm); + error = 0; + } + } + + return error; +} + +/** * pci_choose_state - Choose the power state of a PCI device * @dev: PCI device to be suspended * @state: target sleep state for the whole system. This is the value |