ACPI: introduce two helper functions for _EJ0 and _LCK

Introduce two helper functions, acpi_evaluate_ej0() and
acpi_evaluate_lck(), that will execute the _EJ0 and _LCK ACPI
control methods, respectively, and use them to simplify the
ACPI scan code.

[rjw: Changelog]
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 87b85882b5df..552248b0005b 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -522,3 +522,46 @@ acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
         return acpi_evaluate_object(handle, method, &arg_list, NULL);
 }
 EXPORT_SYMBOL(acpi_execute_simple_method);
+
+/**
+ * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
+ * @handle: ACPI device handle
+ *
+ * Evaluate device's _EJ0 method for hotplug operations.
+ */
+acpi_status acpi_evaluate_ej0(acpi_handle handle)
+{
+        acpi_status status;
+
+        status = acpi_execute_simple_method(handle, "_EJ0", 1);
+        if (status == AE_NOT_FOUND)
+                acpi_handle_warn(handle, "No _EJ0 support for device\n");
+        else if (ACPI_FAILURE(status))
+                acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
+
+        return status;
+}
+
+/**
+ * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
+ * @handle: ACPI device handle
+ * @lock: lock device if non-zero, otherwise unlock device
+ *
+ * Evaluate device's _LCK method if present to lock/unlock device
+ */
+acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
+{
+        acpi_status status;
+
+        status = acpi_execute_simple_method(handle, "_LCK", !!lock);
+        if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
+                if (lock)
+                        acpi_handle_warn(handle,
+                                "Locking device failed (0x%x)\n", status);
+                else
+                        acpi_handle_warn(handle,
+                                "Unlocking device failed (0x%x)\n", status);
+        }
+
+        return status;
+}