ASoC: max98095 codec: Catch driver bugs for biquad channel name

Move the biquad channel names to a separate array and iterate over it in
max98095_get_bq_channel rather than duplicating the hardcoded channel
names. Add an error message if an invalid channel is passed and check
the error in the callers.

Also added a BUILD_BUG_ON to ensure that the bq_mode_name and controls
arrays are the same size.
Signed-off-by: Ryan Mallon <rmallon@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/max98095.c

@@ -1991,12 +1991,19 @@ static void max98095_handle_eq_pdata(struct snd_soc_codec *codec)
 		dev_err(codec->dev, "Failed to add EQ control: %d\n", ret);
 }
 
-static int max98095_get_bq_channel(const char *name)
+static const char *bq_mode_name[] = {"Biquad1 Mode", "Biquad2 Mode"};
+
+static int max98095_get_bq_channel(struct snd_soc_codec *codec,
+				   const char *name)
 {
-	if (strcmp(name, "Biquad1 Mode") == 0)
-		return 0;
-	if (strcmp(name, "Biquad2 Mode") == 0)
-		return 1;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(bq_mode_name); i++)
+		if (strcmp(name, bq_mode_name[i]) == 0)
+			return i;
+
+	/* Shouldn't happen */
+	dev_err(codec->dev, "Bad biquad channel name '%s'\n", name);
 	return -EINVAL;
 }
 
@@ -2006,14 +2013,15 @@ static int max98095_put_bq_enum(struct snd_kcontrol *kcontrol,
 	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
 	struct max98095_priv *max98095 = snd_soc_codec_get_drvdata(codec);
 	struct max98095_pdata *pdata = max98095->pdata;
-	int channel = max98095_get_bq_channel(kcontrol->id.name);
+	int channel = max98095_get_bq_channel(codec, kcontrol->id.name);
 	struct max98095_cdata *cdata;
 	int sel = ucontrol->value.integer.value[0];
 	struct max98095_biquad_cfg *coef_set;
 	int fs, best, best_val, i;
 	int regmask, regsave;
 
-	BUG_ON(channel > 1);
+	if (channel < 0)
+		return channel;
 
 	if (!pdata || !max98095->bq_textcnt)
 		return 0;
@@ -2065,9 +2073,12 @@ static int max98095_get_bq_enum(struct snd_kcontrol *kcontrol,
 {
 	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
 	struct max98095_priv *max98095 = snd_soc_codec_get_drvdata(codec);
-	int channel = max98095_get_bq_channel(kcontrol->id.name);
+	int channel = max98095_get_bq_channel(codec, kcontrol->id.name);
 	struct max98095_cdata *cdata;
 
+	if (channel < 0)
+		return channel;
+
 	cdata = &max98095->dai[channel];
 	ucontrol->value.enumerated.item[0] = cdata->bq_sel;
 
@@ -2085,15 +2096,16 @@ static void max98095_handle_bq_pdata(struct snd_soc_codec *codec)
 	int ret;
 
 	struct snd_kcontrol_new controls[] = {
-		SOC_ENUM_EXT("Biquad1 Mode",
+		SOC_ENUM_EXT((char *)bq_mode_name[0],
 			max98095->bq_enum,
 			max98095_get_bq_enum,
 			max98095_put_bq_enum),
-		SOC_ENUM_EXT("Biquad2 Mode",
+		SOC_ENUM_EXT((char *)bq_mode_name[1],
 			max98095->bq_enum,
 			max98095_get_bq_enum,
 			max98095_put_bq_enum),
 	};
+	BUILD_BUG_ON(ARRAY_SIZE(controls) != ARRAY_SIZE(bq_mode_name));
 
 	cfg = pdata->bq_cfg;
 	cfgcnt = pdata->bq_cfgcnt;