// Helper routines for R-Car sound ADG.
 //
 //  Copyright (C) 2013  Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
-
 #include <linux/clk-provider.h>
+#include <linux/clkdev.h>
 #include "rsnd.h"
 
 #define CLKA   0
        }
 }
 
+#define NULL_CLK "rsnd_adg_null"
+static struct clk *rsnd_adg_null_clk_get(struct rsnd_priv *priv)
+{
+       static struct clk_hw *hw;
+       struct device *dev = rsnd_priv_to_dev(priv);
+
+       if (!hw) {
+               struct clk_hw *_hw;
+               int ret;
+
+               _hw = clk_hw_register_fixed_rate_with_accuracy(dev, NULL_CLK, NULL, 0, 0, 0);
+               if (IS_ERR(_hw))
+                       return NULL;
+
+               ret = of_clk_add_hw_provider(dev->of_node, of_clk_hw_simple_get, _hw);
+               if (ret < 0)
+                       clk_hw_unregister_fixed_rate(_hw);
+
+               hw = _hw;
+       }
+
+       return clk_hw_get_clk(hw, NULL_CLK);
+}
+
 static void rsnd_adg_get_clkin(struct rsnd_priv *priv,
                               struct rsnd_adg *adg)
 {
        for (i = 0; i < CLKMAX; i++) {
                struct clk *clk = devm_clk_get(dev, clk_name[i]);
 
-               adg->clk[i] = IS_ERR(clk) ? NULL : clk;
+               if (IS_ERR(clk))
+                       clk = rsnd_adg_null_clk_get(priv);
+               if (IS_ERR(clk))
+                       dev_err(dev, "no adg clock (%s)\n", clk_name[i]);
+
+               adg->clk[i] = clk;
        }
 }