ACPI / PM: Move device PM functions related to sleep states

Introduce helper function returning the target sleep state of the
system and use it to move the remaining device power management
functions from sleep.c to device_pm.c.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index b4f03f9..7ddd934 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -198,6 +198,31 @@
 }
 EXPORT_SYMBOL_GPL(acpi_device_power_state);
 
+/**
+ * acpi_pm_device_sleep_state - Get preferred power state of ACPI device.
+ * @dev: Device whose preferred target power state to return.
+ * @d_min_p: Location to store the upper limit of the allowed states range.
+ * @d_max_in: Deepest low-power state to take into consideration.
+ * Return value: Preferred power state of the device on success, -ENODEV
+ * (if there's no 'struct acpi_device' for @dev) or -EINVAL on failure
+ *
+ * The caller must ensure that @dev is valid before using this function.
+ */
+int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p, int d_max_in)
+{
+	acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
+	struct acpi_device *adev;
+
+	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
+		dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
+		return -ENODEV;
+	}
+
+	return acpi_device_power_state(dev, adev, acpi_target_system_state(),
+				       d_max_in, d_min_p);
+}
+EXPORT_SYMBOL(acpi_pm_device_sleep_state);
+
 #ifdef CONFIG_PM_RUNTIME
 /**
  * __acpi_device_run_wake - Enable/disable runtime remote wakeup for device.
@@ -274,4 +299,33 @@
 		acpi_enable_wakeup_device_power(adev, target_state) :
 		acpi_disable_wakeup_device_power(adev);
 }
+
+/**
+ * acpi_pm_device_sleep_wake - Enable or disable device to wake up the system.
+ * @dev: Device to enable/desible to wake up the system from sleep states.
+ * @enable: Whether to enable or disable @dev to wake up the system.
+ */
+int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
+{
+	acpi_handle handle;
+	struct acpi_device *adev;
+	int error;
+
+	if (!device_can_wakeup(dev))
+		return -EINVAL;
+
+	handle = DEVICE_ACPI_HANDLE(dev);
+	if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
+		dev_dbg(dev, "ACPI handle without context in %s!\n", __func__);
+		return -ENODEV;
+	}
+
+	error = __acpi_device_sleep_wake(adev, acpi_target_system_state(),
+					 enable);
+	if (!error)
+		dev_info(dev, "System wakeup %s by ACPI\n",
+				enable ? "enabled" : "disabled");
+
+	return error;
+}
 #endif /* CONFIG_PM_SLEEP */