PCI ACPI: Rework PCI handling of wake-up
* Introduce function acpi_pm_device_sleep_wake() for enabling and
disabling the system wake-up capability of devices that are power
manageable by ACPI.
* Introduce function acpi_bus_can_wakeup() allowing other (dependent)
subsystems to check if ACPI is able to enable the system wake-up
capability of given device.
* Introduce callback .sleep_wake() in struct pci_platform_pm_ops and
for the ACPI PCI 'driver' make it use acpi_pm_device_sleep_wake().
* Introduce callback .can_wakeup() in struct pci_platform_pm_ops and
for the ACPI 'driver' make it use acpi_bus_can_wakeup().
* Move the PME# handlig code out of pci_enable_wake() and split it
into two functions, pci_pme_capable() and pci_pme_active(),
allowing the caller to check if given device is capable of
generating PME# from given power state and to enable/disable the
device's PME# functionality, respectively.
* Modify pci_enable_wake() to use the new ACPI callbacks and the new
PME#-related functions.
* Drop the generic .platform_enable_wakeup() callback that is not
used any more.
* Introduce device_set_wakeup_capable() that will set the
power.can_wakeup flag of given device.
* Rework PCI device PM initialization so that, if given device is
capable of generating wake-up events, either natively through the
PME# mechanism, or with the help of the platform, its
power.can_wakeup flag is set and its power.should_wakeup flag is
unset as appropriate.
* Make ACPI set the power.can_wakeup flag for devices found to be
wake-up capable by it.
* Make the ACPI wake-up code enable/disable GPEs for devices that
have the wakeup.flags.prepared flag set (which means that their
wake-up power has been enabled).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 20e2807..a6b1b6f 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -380,7 +380,8 @@
int pci_set_platform_pm(struct pci_platform_pm_ops *ops)
{
- if (!ops->is_manageable || !ops->set_state || !ops->choose_state)
+ if (!ops->is_manageable || !ops->set_state || !ops->choose_state
+ || !ops->sleep_wake || !ops->can_wakeup)
return -EINVAL;
pci_platform_pm = ops;
return 0;
@@ -403,6 +404,17 @@
pci_platform_pm->choose_state(dev) : PCI_POWER_ERROR;
}
+static inline bool platform_pci_can_wakeup(struct pci_dev *dev)
+{
+ return pci_platform_pm ? pci_platform_pm->can_wakeup(dev) : false;
+}
+
+static inline int platform_pci_sleep_wake(struct pci_dev *dev, bool enable)
+{
+ return pci_platform_pm ?
+ pci_platform_pm->sleep_wake(dev, enable) : -ENODEV;
+}
+
/**
* pci_raw_set_power_state - Use PCI PM registers to set the power state of
* given PCI device
@@ -1036,6 +1048,56 @@
}
/**
+ * pci_pme_capable - check the capability of PCI device to generate PME#
+ * @dev: PCI device to handle.
+ * @pm: PCI PM capability offset of the device.
+ * @state: PCI state from which device will issue PME#.
+ */
+static bool pci_pme_capable(struct pci_dev *dev, int pm, pci_power_t state)
+{
+ u16 pmc;
+
+ if (!pm)
+ return false;
+
+ /* Check device's ability to generate PME# from given state */
+ pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
+
+ pmc &= PCI_PM_CAP_PME_MASK;
+ pmc >>= ffs(PCI_PM_CAP_PME_MASK) - 1; /* First bit of mask */
+
+ return !!(pmc & (1 << state));
+}
+
+/**
+ * pci_pme_active - enable or disable PCI device's PME# function
+ * @dev: PCI device to handle.
+ * @pm: PCI PM capability offset of the device.
+ * @enable: 'true' to enable PME# generation; 'false' to disable it.
+ *
+ * The caller must verify that the device is capable of generating PME# before
+ * calling this function with @enable equal to 'true'.
+ */
+static void pci_pme_active(struct pci_dev *dev, int pm, bool enable)
+{
+ u16 pmcsr;
+
+ if (!pm)
+ return;
+
+ pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
+ /* Clear PME_Status by writing 1 to it and enable PME# */
+ pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
+ if (!enable)
+ pmcsr &= ~PCI_PM_CTRL_PME_ENABLE;
+
+ pci_write_config_word(dev, pm + PCI_PM_CTRL, pmcsr);
+
+ dev_printk(KERN_INFO, &dev->dev, "PME# %s\n",
+ enable ? "enabled" : "disabled");
+}
+
+/**
* pci_enable_wake - enable PCI device as wakeup event source
* @dev: PCI device affected
* @state: PCI state from which device will issue wakeup events
@@ -1046,66 +1108,83 @@
* called automatically by this routine.
*
* Devices with legacy power management (no standard PCI PM capabilities)
- * always require such platform hooks. Depending on the platform, devices
- * supporting the standard PCI PME# signal may require such platform hooks;
- * they always update bits in config space to allow PME# generation.
+ * always require such platform hooks.
*
- * -EIO is returned if the device can't ever be a wakeup event source.
- * -EINVAL is returned if the device can't generate wakeup events from
- * the specified PCI state. Returns zero if the operation is successful.
+ * RETURN VALUE:
+ * 0 is returned on success
+ * -EINVAL is returned if device is not supposed to wake up the system
+ * Error code depending on the platform is returned if both the platform and
+ * the native mechanism fail to enable the generation of wake-up events
*/
int pci_enable_wake(struct pci_dev *dev, pci_power_t state, int enable)
{
int pm;
- int status;
- u16 value;
+ int error = 0;
+ bool pme_done = false;
- /* Note that drivers should verify device_may_wakeup(&dev->dev)
- * before calling this function. Platform code should report
- * errors when drivers try to enable wakeup on devices that
- * can't issue wakeups, or on which wakeups were disabled by
- * userspace updating the /sys/devices.../power/wakeup file.
+ if (!device_may_wakeup(&dev->dev))
+ return -EINVAL;
+
+ /*
+ * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don
+ * Anderson we should be doing PME# wake enable followed by ACPI wake
+ * enable. To disable wake-up we call the platform first, for symmetry.
*/
- status = call_platform_enable_wakeup(&dev->dev, enable);
+ if (!enable && platform_pci_can_wakeup(dev))
+ error = platform_pci_sleep_wake(dev, false);
+
+ pm = pci_find_capability(dev, PCI_CAP_ID_PM);
+ if (!enable || pci_pme_capable(dev, pm, state)) {
+ pci_pme_active(dev, pm, enable);
+ pme_done = true;
+ }
+
+ if (enable && platform_pci_can_wakeup(dev))
+ error = platform_pci_sleep_wake(dev, true);
+
+ return pme_done ? 0 : error;
+}
+
+/**
+ * pci_pm_init - Initialize PM functions of given PCI device
+ * @dev: PCI device to handle.
+ */
+void pci_pm_init(struct pci_dev *dev)
+{
+ int pm;
+ u16 pmc;
/* find PCI PM capability in list */
pm = pci_find_capability(dev, PCI_CAP_ID_PM);
-
- /* If device doesn't support PM Capabilities, but caller wants to
- * disable wake events, it's a NOP. Otherwise fail unless the
- * platform hooks handled this legacy device already.
- */
if (!pm)
- return enable ? status : 0;
-
+ return;
/* Check device's ability to generate PME# */
- pci_read_config_word(dev,pm+PCI_PM_PMC,&value);
+ pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
- value &= PCI_PM_CAP_PME_MASK;
- value >>= ffs(PCI_PM_CAP_PME_MASK) - 1; /* First bit of mask */
-
- /* Check if it can generate PME# from requested state. */
- if (!value || !(value & (1 << state))) {
- /* if it can't, revert what the platform hook changed,
- * always reporting the base "EINVAL, can't PME#" error
- */
- if (enable)
- call_platform_enable_wakeup(&dev->dev, 0);
- return enable ? -EINVAL : 0;
+ if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
+ dev_err(&dev->dev, "unsupported PM cap regs version (%u)\n",
+ pmc & PCI_PM_CAP_VER_MASK);
+ return;
}
- pci_read_config_word(dev, pm + PCI_PM_CTRL, &value);
-
- /* Clear PME_Status by writing 1 to it and enable PME# */
- value |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE;
-
- if (!enable)
- value &= ~PCI_PM_CTRL_PME_ENABLE;
-
- pci_write_config_word(dev, pm + PCI_PM_CTRL, value);
-
- return 0;
+ if (pmc & PCI_PM_CAP_PME_MASK) {
+ dev_printk(KERN_INFO, &dev->dev,
+ "PME# supported from%s%s%s%s%s\n",
+ (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "",
+ (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "",
+ (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "",
+ (pmc & PCI_PM_CAP_PME_D3) ? " D3hot" : "",
+ (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : "");
+ /*
+ * Make device's PM flags reflect the wake-up capability, but
+ * let the user space enable it to wake up the system as needed.
+ */
+ device_set_wakeup_capable(&dev->dev, true);
+ device_set_wakeup_enable(&dev->dev, false);
+ /* Disable the PME# generation functionality */
+ pci_pme_active(dev, pm, false);
+ }
}
int
