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Diffstat (limited to 'drivers/platform/x86/firmware_attributes_class.c')
-rw-r--r--drivers/platform/x86/firmware_attributes_class.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/platform/x86/firmware_attributes_class.c b/drivers/platform/x86/firmware_attributes_class.c
new file mode 100644
index 000000000..fafe8eaf6
--- /dev/null
+++ b/drivers/platform/x86/firmware_attributes_class.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/* Firmware attributes class helper module */
+
+#include <linux/mutex.h>
+#include <linux/device/class.h>
+#include <linux/module.h>
+#include "firmware_attributes_class.h"
+
+static DEFINE_MUTEX(fw_attr_lock);
+static int fw_attr_inuse;
+
+static struct class firmware_attributes_class = {
+ .name = "firmware-attributes",
+};
+
+int fw_attributes_class_get(struct class **fw_attr_class)
+{
+ int err;
+
+ mutex_lock(&fw_attr_lock);
+ if (!fw_attr_inuse) { /*first time class is being used*/
+ err = class_register(&firmware_attributes_class);
+ if (err) {
+ mutex_unlock(&fw_attr_lock);
+ return err;
+ }
+ }
+ fw_attr_inuse++;
+ *fw_attr_class = &firmware_attributes_class;
+ mutex_unlock(&fw_attr_lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fw_attributes_class_get);
+
+int fw_attributes_class_put(void)
+{
+ mutex_lock(&fw_attr_lock);
+ if (!fw_attr_inuse) {
+ mutex_unlock(&fw_attr_lock);
+ return -EINVAL;
+ }
+ fw_attr_inuse--;
+ if (!fw_attr_inuse) /* No more consumers */
+ class_unregister(&firmware_attributes_class);
+ mutex_unlock(&fw_attr_lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fw_attributes_class_put);
+
+MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
+MODULE_LICENSE("GPL");