1 files changed, 74 insertions, 0 deletions
diff --git a/drivers/of/module.c b/drivers/of/module.c
new file mode 100644
index 0000000000..0e8aa974f0
--- /dev/null
+++ b/drivers/of/module.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Linux kernel module helpers.
+ */
+
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+ssize_t of_modalias(const struct device_node *np, char *str, ssize_t len)
+{
+	const char *compat;
+	char *c;
+	struct property *p;
+	ssize_t csize;
+	ssize_t tsize;
+
+	/* Name & Type */
+	/* %p eats all alphanum characters, so %c must be used here */
+	csize = snprintf(str, len, "of:N%pOFn%c%s", np, 'T',
+			 of_node_get_device_type(np));
+	tsize = csize;
+	len -= csize;
+	if (str)
+		str += csize;
+
+	of_property_for_each_string(np, "compatible", p, compat) {
+		csize = strlen(compat) + 1;
+		tsize += csize;
+		if (csize > len)
+			continue;
+
+		csize = snprintf(str, len, "C%s", compat);
+		for (c = str; c; ) {
+			c = strchr(c, ' ');
+			if (c)
+				*c++ = '_';
+		}
+		len -= csize;
+		str += csize;
+	}
+
+	return tsize;
+}
+
+int of_request_module(const struct device_node *np)
+{
+	char *str;
+	ssize_t size;
+	int ret;
+
+	if (!np)
+		return -ENODEV;
+
+	size = of_modalias(np, NULL, 0);
+	if (size < 0)
+		return size;
+
+	/* Reserve an additional byte for the trailing '\0' */
+	size++;
+
+	str = kmalloc(size, GFP_KERNEL);
+	if (!str)
+		return -ENOMEM;
+
+	of_modalias(np, str, size);
+	str[size - 1] = '\0';
+	ret = request_module(str);
+	kfree(str);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_request_module);