PNPACPI: Add support for remote wakeup

This patch (as1354) adds remote-wakeup support to the pnpacpi driver.
The new can_wakeup method also allows other PNP protocol drivers
(pnpbios or iaspnp) to add wakeup support, but I don't know enough
about how they work to actually do it.

Signed-off-by: Alan Stern <[e-mail]>
Reviewed-by: Bjorn Helgaas <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

drivers/pnp/core.c

···
 	list_add_tail(&dev->global_list, &pnp_global);
 	list_add_tail(&dev->protocol_list, &dev->protocol->devices);
 	spin_unlock(&pnp_lock);
+	if (dev->protocol->can_wakeup)
+		device_set_wakeup_capable(&dev->dev,
+				dev->protocol->can_wakeup(dev));
 	return device_register(&dev->dev);
 }
 

drivers/pnp/pnpacpi/core.c

···
 }
 
 #ifdef CONFIG_ACPI_SLEEP
+static bool pnpacpi_can_wakeup(struct pnp_dev *dev)
+{
+	struct acpi_device *acpi_dev = dev->data;
+	acpi_handle handle = acpi_dev->handle;
+
+	return acpi_bus_can_wakeup(handle);
+}
+
 static int pnpacpi_suspend(struct pnp_dev *dev, pm_message_t state)
 {
 	struct acpi_device *acpi_dev = dev->data;
 	acpi_handle handle = acpi_dev->handle;
 	int power_state;
 
+	if (device_can_wakeup(&dev->dev)) {
+		int rc = acpi_pm_device_sleep_wake(&dev->dev,
+				device_may_wakeup(&dev->dev));
+
+		if (rc)
+			return rc;
+	}
 	power_state = acpi_pm_device_sleep_state(&dev->dev, NULL);
 	if (power_state < 0)
 		power_state = (state.event == PM_EVENT_ON) ?
 				ACPI_STATE_D0 : ACPI_STATE_D3;
 
+	/* acpi_bus_set_power() often fails (keyboard port can't be
+	 * powered-down?), and in any case, our return value is ignored
+	 * by pnp_bus_suspend().  Hence we don't revert the wakeup
+	 * setting if the set_power fails.
+	 */
 	return acpi_bus_set_power(handle, power_state);
 }
 
···
 	struct acpi_device *acpi_dev = dev->data;
 	acpi_handle handle = acpi_dev->handle;
 
+	if (device_may_wakeup(&dev->dev))
+		acpi_pm_device_sleep_wake(&dev->dev, false);
 	return acpi_bus_set_power(handle, ACPI_STATE_D0);
 }
 #endif
···
 	.set	 = pnpacpi_set_resources,
 	.disable = pnpacpi_disable_resources,
 #ifdef CONFIG_ACPI_SLEEP
+	.can_wakeup = pnpacpi_can_wakeup,
 	.suspend = pnpacpi_suspend,
 	.resume = pnpacpi_resume,
 #endif

include/linux/pnp.h

···
 	int (*disable) (struct pnp_dev *dev);
 
 	/* protocol specific suspend/resume */
+	bool (*can_wakeup) (struct pnp_dev *dev);
 	int (*suspend) (struct pnp_dev * dev, pm_message_t state);
 	int (*resume) (struct pnp_dev * dev);