PCI / ACPI / PM: Platform support for PCI PME wake-up

Although the majority of PCI devices can generate PMEs that in
principle may be used to wake up devices suspended at run time,
platform support is generally necessary to convert PMEs into wake-up
events that can be delivered to the kernel.  If ACPI is used for this
purpose, PME signals generated by a PCI device will trigger the ACPI
GPE associated with the device to generate an ACPI wake-up event that
we can set up a handler for, provided that everything is configured
correctly.

Unfortunately, the subset of PCI devices that have GPEs associated
with them is quite limited.  The devices without dedicated GPEs have
to rely on the GPEs associated with other devices (in the majority of
cases their upstream bridges and, possibly, the root bridge) to
generate ACPI wake-up events in response to PME signals from them.

Add ACPI platform support for PCI PME wake-up:
o Add a framework making is possible to use ACPI system notify
  handlers for run-time PM.
o Add new PCI platform callback ->run_wake() to struct
  pci_platform_pm_ops allowing us to enable/disable the platform to
  generate wake-up events for given device.  Implemet this callback
  for the ACPI platform.
o Define ACPI wake-up handlers for PCI devices and PCI root buses and
  make the PCI-ACPI binding code register wake-up notifiers for all
  PCI devices present in the ACPI tables.
o Add function pci_dev_run_wake() which can be used by PCI drivers to
  check if given device is capable of generating wake-up events at
  run time.

Developed in cooperation with Matthew Garrett <[email protected]>.

Signed-off-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Jesse Barnes <[email protected]>

drivers/acpi/internal.h

@@ -36,8 +36,6 @@ static inline int acpi_debug_init(void) { return 0; }
 int acpi_power_init(void);
 int acpi_device_sleep_wake(struct acpi_device *dev,
                            int enable, int sleep_state, int dev_state);
-int acpi_enable_wakeup_device_power(struct acpi_device *dev, int sleep_state);
-int acpi_disable_wakeup_device_power(struct acpi_device *dev);
 int acpi_power_get_inferred_state(struct acpi_device *device);
 int acpi_power_transition(struct acpi_device *device, int state);
 extern int acpi_power_nocheck;

drivers/acpi/pci_bind.c

@@ -26,7 +26,9 @@
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/pci.h>
+#include <linux/pci-acpi.h>
 #include <linux/acpi.h>
+#include <linux/pm_runtime.h>
 #include <acpi/acpi_bus.h>
 #include <acpi/acpi_drivers.h>
 
@@ -38,7 +40,13 @@ static int acpi_pci_unbind(struct acpi_device *device)
 	struct pci_dev *dev;
 
 	dev = acpi_get_pci_dev(device->handle);
-	if (!dev || !dev->subordinate)
+	if (!dev)
+		goto out;
+
+	device_set_run_wake(&dev->dev, false);
+	pci_acpi_remove_pm_notifier(device);
+
+	if (!dev->subordinate)
 		goto out;
 
 	acpi_pci_irq_del_prt(dev->subordinate);
@@ -62,6 +70,10 @@ static int acpi_pci_bind(struct acpi_device *device)
 	if (!dev)
 		return 0;
 
+	pci_acpi_add_pm_notifier(device, dev);
+	if (device->wakeup.flags.run_wake)
+		device_set_run_wake(&dev->dev, true);
+
 	/*
 	 * Install the 'bind' function to facilitate callbacks for
 	 * children of the P2P bridge.

drivers/acpi/pci_root.c

@@ -30,6 +30,7 @@
 #include <linux/proc_fs.h>
 #include <linux/spinlock.h>
 #include <linux/pm.h>
+#include <linux/pm_runtime.h>
 #include <linux/pci.h>
 #include <linux/pci-acpi.h>
 #include <linux/acpi.h>
@@ -528,6 +529,10 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 	if (flags != base_flags)
 		acpi_pci_osc_support(root, flags);
 
+	pci_acpi_add_bus_pm_notifier(device, root->bus);
+	if (device->wakeup.flags.run_wake)
+		device_set_run_wake(root->bus->bridge, true);
+
 	return 0;
 
 end:
@@ -549,6 +554,9 @@ static int acpi_pci_root_remove(struct acpi_device *device, int type)
 {
 	struct acpi_pci_root *root = acpi_driver_data(device);
 
+	device_set_run_wake(root->bus->bridge, false);
+	pci_acpi_remove_bus_pm_notifier(device);
+
 	kfree(root);
 	return 0;
 }

drivers/acpi/scan.c

@@ -753,6 +753,7 @@ static void acpi_bus_set_run_wake_flags(struct acpi_device *device)
 	acpi_event_status event_status;
 
 	device->wakeup.run_wake_count = 0;
+	device->wakeup.flags.notifier_present = 0;
 
 	/* Power button, Lid switch always enable wakeup */
 	if (!acpi_match_device_ids(device, button_device_ids)) {