ACPI: HED: Install Notify() handler directly

Modify the ACPI HED driver to install its own Notify() handler directly
instead of providing an ACPI driver .notify() callback.

This will allow the ACPI driver .notify() callback to be eliminated and
it will allow the HED driver to be switched over to a platform one in
the future.
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>
[ rjw: Subject and changelog edits, whitespace adjustments ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/hed.c

@@ -42,22 +42,32 @@ EXPORT_SYMBOL_GPL(unregister_acpi_hed_notifier);
  * it is used by HEST Generic Hardware Error Source with notify type
  * SCI.
  */
-static void acpi_hed_notify(struct acpi_device *device, u32 event)
+static void acpi_hed_notify(acpi_handle handle, u32 event, void *data)
 {
 	blocking_notifier_call_chain(&acpi_hed_notify_list, 0, NULL);
 }
 
 static int acpi_hed_add(struct acpi_device *device)
 {
+	int err;
+
 	/* Only one hardware error device */
 	if (hed_handle)
 		return -EINVAL;
 	hed_handle = device->handle;
-	return 0;
+
+	err = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
+					      acpi_hed_notify);
+	if (err)
+		hed_handle = NULL;
+
+	return err;
 }
 
 static void acpi_hed_remove(struct acpi_device *device)
 {
+	acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
+				       acpi_hed_notify);
 	hed_handle = NULL;
 }
 
@@ -68,7 +78,6 @@ static struct acpi_driver acpi_hed_driver = {
 	.ops = {
 		.add = acpi_hed_add,
 		.remove = acpi_hed_remove,
-		.notify = acpi_hed_notify,
 	},
 };
 module_acpi_driver(acpi_hed_driver);