device: added register_class_devname() API

this allows drivers to register generic device names for a device
class, with automatic class instance handling

1 files changed, 36 insertions, 0 deletions

diff --git a/src/drivers/device/cdev.cpp b/src/drivers/device/cdev.cpp
index 47ebcd40a..7954ce5ab 100644
--- a/src/drivers/device/cdev.cpp
+++ b/src/drivers/device/cdev.cpp
@@ -109,6 +109,42 @@ CDev::~CDev()
 }
 
 int
+CDev::register_class_devname(const char *class_devname)
+{
+	if (class_devname == nullptr) {
+		return -EINVAL;
+	}
+	int class_instance = 0;
+	int ret = -ENOSPC;
+	while (class_instance < 4) {
+		if (class_instance == 0) {
+			ret = register_driver(class_devname, &fops, 0666, (void *)this);
+			if (ret == OK) break;
+		} else {
+			char name[32];
+			snprintf(name, sizeof(name), "%s%u", class_devname, class_instance);
+			ret = register_driver(name, &fops, 0666, (void *)this);
+			if (ret == OK) break;
+		}
+		class_instance++;
+	}
+	if (class_instance == 4)
+		return ret;
+	return class_instance;
+}
+
+int
+CDev::unregister_class_devname(const char *class_devname, unsigned class_instance)
+{
+	if (class_instance > 0) {
+		char name[32];
+		snprintf(name, sizeof(name), "%s%u", class_devname, class_instance);
+		return unregister_driver(name);
+	}
+	return unregister_driver(class_devname);
+}
+
+int
 CDev::init()
 {
 	// base class init first