ACPI / PM: Use ACPI_COMPANION() to get ACPI companions of devices

The ACPI device PM code in device_pm.c uses a special function,
acpi_dev_pm_get_node(), to obtain an ACPI companion object of a given
device.  However, that is not necessary any more after recent changes
that introduced the ACPI_COMPANION() macro serving exactly the same
purpose, but working in a much more straightforward way.  For this
reason, drop acpi_dev_pm_get_node() and use ACPI_COMPANION() instead
of it everywhere.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/acpi/device_pm.c

@@ -712,18 +712,6 @@ int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
 }
 #endif /* CONFIG_PM_SLEEP */
 
-/**
- * acpi_dev_pm_get_node - Get ACPI device node for the given physical device.
- * @dev: Device to get the ACPI node for.
- */
-struct acpi_device *acpi_dev_pm_get_node(struct device *dev)
-{
-	acpi_handle handle = ACPI_HANDLE(dev);
-	struct acpi_device *adev;
-
-	return handle && !acpi_bus_get_device(handle, &adev) ? adev : NULL;
-}
-
 /**
  * acpi_dev_pm_low_power - Put ACPI device into a low-power state.
  * @dev: Device to put into a low-power state.
@@ -764,7 +752,7 @@ static int acpi_dev_pm_full_power(struct acpi_device *adev)
  */
 int acpi_dev_runtime_suspend(struct device *dev)
 {
-	struct acpi_device *adev = acpi_dev_pm_get_node(dev);
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 	bool remote_wakeup;
 	int error;
 
@@ -795,7 +783,7 @@ EXPORT_SYMBOL_GPL(acpi_dev_runtime_suspend);
  */
 int acpi_dev_runtime_resume(struct device *dev)
 {
-	struct acpi_device *adev = acpi_dev_pm_get_node(dev);
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 	int error;
 
 	if (!adev)
@@ -848,7 +836,7 @@ EXPORT_SYMBOL_GPL(acpi_subsys_runtime_resume);
  */
 int acpi_dev_suspend_late(struct device *dev)
 {
-	struct acpi_device *adev = acpi_dev_pm_get_node(dev);
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 	u32 target_state;
 	bool wakeup;
 	int error;
@@ -880,7 +868,7 @@ EXPORT_SYMBOL_GPL(acpi_dev_suspend_late);
  */
 int acpi_dev_resume_early(struct device *dev)
 {
-	struct acpi_device *adev = acpi_dev_pm_get_node(dev);
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 	int error;
 
 	if (!adev)
@@ -971,7 +959,7 @@ static struct dev_pm_domain acpi_general_pm_domain = {
  */
 int acpi_dev_pm_attach(struct device *dev, bool power_on)
 {
-	struct acpi_device *adev = acpi_dev_pm_get_node(dev);
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 
 	if (!adev)
 		return -ENODEV;
@@ -1003,7 +991,7 @@ EXPORT_SYMBOL_GPL(acpi_dev_pm_attach);
  */
 void acpi_dev_pm_detach(struct device *dev, bool power_off)
 {
-	struct acpi_device *adev = acpi_dev_pm_get_node(dev);
+	struct acpi_device *adev = ACPI_COMPANION(dev);
 
 	if (adev && dev->pm_domain == &acpi_general_pm_domain) {
 		dev->pm_domain = NULL;