clkdev: add clkdev_create() helper

Add a helper to allocate and add a clk_lookup structure.  This can not
only be used in several places in clkdev.c to simplify the code, but
more importantly, can be used by callers of the clkdev code to simplify
their clkdev creation and registration.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index e112e13..c0eaf09 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -274,6 +274,19 @@
 	return &cla->cl;
 }
 
+static struct clk_lookup *
+vclkdev_create(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
+	va_list ap)
+{
+	struct clk_lookup *cl;
+
+	cl = vclkdev_alloc(hw, con_id, dev_fmt, ap);
+	if (cl)
+		__clkdev_add(cl);
+
+	return cl;
+}
+
 struct clk_lookup * __init_refok
 clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
 {
@@ -288,6 +301,29 @@
 }
 EXPORT_SYMBOL(clkdev_alloc);
 
+/**
+ * clkdev_create - allocate and add a clkdev lookup structure
+ * @clk: struct clk to associate with all clk_lookups
+ * @con_id: connection ID string on device
+ * @dev_fmt: format string describing device name
+ *
+ * Returns a clk_lookup structure, which can be later unregistered and
+ * freed.
+ */
+struct clk_lookup *clkdev_create(struct clk *clk, const char *con_id,
+	const char *dev_fmt, ...)
+{
+	struct clk_lookup *cl;
+	va_list ap;
+
+	va_start(ap, dev_fmt);
+	cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap);
+	va_end(ap);
+
+	return cl;
+}
+EXPORT_SYMBOL_GPL(clkdev_create);
+
 int clk_add_alias(const char *alias, const char *alias_dev_name,
 	const char *con_id, struct device *dev)
 {
@@ -297,12 +333,10 @@
 	if (IS_ERR(r))
 		return PTR_ERR(r);
 
-	l = clkdev_alloc(r, alias, alias_dev_name);
+	l = clkdev_create(r, alias, "%s", alias_dev_name);
 	clk_put(r);
-	if (!l)
-		return -ENODEV;
-	clkdev_add(l);
-	return 0;
+
+	return l ? 0 : -ENODEV;
 }
 EXPORT_SYMBOL(clk_add_alias);
 
@@ -342,15 +376,10 @@
 		return PTR_ERR(clk);
 
 	va_start(ap, dev_fmt);
-	cl = vclkdev_alloc(__clk_get_hw(clk), con_id, dev_fmt, ap);
+	cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap);
 	va_end(ap);
 
-	if (!cl)
-		return -ENOMEM;
-
-	clkdev_add(cl);
-
-	return 0;
+	return cl ? 0 : -ENOMEM;
 }
 EXPORT_SYMBOL(clk_register_clkdev);