ASoC: rsnd: Fix possible NULL pointer dereference

25165f79ad
("ASoC: rsnd: enable clock-frequency for both 44.1kHz/48kHz")
supports both 44.1kHz/48kHz clock-frequency settings for ADG
which will be used for AUDIO_OLKOUTn.
But some board doesn't need it, thus, it is not mandatory.

But, above patch didn't care about the case of "clock-frequency" DT
property was not present.
This patch ignores ADG settings if AUDIO_OLKOUTn was not used.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
[Kuninori: tidyup not to break non AUDIO_OLKOUTn case]
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sh/rcar/adg.c

@@ -453,13 +453,18 @@ static void rsnd_adg_get_clkout(struct rsnd_priv *priv,
 		[CLKI] = 0x2,
 	};
 
-	of_property_read_u32(np, "#clock-cells", &count);
+	ckr = 0;
+	rbga = 2; /* default 1/6 */
+	rbgb = 2; /* default 1/6 */
 
 	/*
 	 * ADG supports BRRA/BRRB output only
 	 * this means all clkout0/1/2/3 will be same rate
 	 */
 	prop = of_find_property(np, "clock-frequency", NULL);
+	if (!prop)
+		goto rsnd_adg_get_clkout_end;
+
 	req_size = prop->length / sizeof(u32);
 
 	of_property_read_u32_array(np, "clock-frequency", req_rate, req_size);
@@ -472,6 +477,9 @@ static void rsnd_adg_get_clkout(struct rsnd_priv *priv,
 			req_48kHz_rate = req_rate[i];
 	}
 
+	if (req_rate[0] % 48000 == 0)
+		adg->flags = AUDIO_OUT_48;
+
 	/*
 	 * This driver is assuming that AUDIO_CLKA/AUDIO_CLKB/AUDIO_CLKC
 	 * have 44.1kHz or 48kHz base clocks for now.
@@ -481,9 +489,6 @@ static void rsnd_adg_get_clkout(struct rsnd_priv *priv,
 	 *	rsnd_adg_ssi_clk_try_start()
 	 *	rsnd_ssi_master_clk_start()
 	 */
-	ckr = 0;
-	rbga = 2; /* default 1/6 */
-	rbgb = 2; /* default 1/6 */
 	adg->rbga_rate_for_441khz	= 0;
 	adg->rbgb_rate_for_48khz	= 0;
 	for_each_rsnd_clk(clk, adg, i) {
@@ -528,6 +533,7 @@ static void rsnd_adg_get_clkout(struct rsnd_priv *priv,
 	 * this means all clkout0/1/2/3 will be * same rate
 	 */
 
+	of_property_read_u32(np, "#clock-cells", &count);
 	/*
 	 * for clkout
 	 */
@@ -557,13 +563,11 @@ static void rsnd_adg_get_clkout(struct rsnd_priv *priv,
 				    &adg->onecell);
 	}
 
+rsnd_adg_get_clkout_end:
 	adg->ckr = ckr;
 	adg->rbga = rbga;
 	adg->rbgb = rbgb;
 
-	if (req_rate[0] % 48000 == 0)
-		adg->flags = AUDIO_OUT_48;
-
 	for_each_rsnd_clkout(clk, adg, i)
 		dev_dbg(dev, "clkout %d : %p : %ld\n", i, clk, clk_get_rate(clk));
 	dev_dbg(dev, "BRGCKR = 0x%08x, BRRA/BRRB = 0x%x/0x%x\n",