ASoC: arizona: Add a notifier chain for CODEC events

Add a notifier chain that can be used from the machine driver to catch
events generated by the CODEC.
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/linux/mfd/arizona/core.h

@@ -14,6 +14,7 @@
 #define _WM_ARIZONA_CORE_H
 
 #include <linux/interrupt.h>
+#include <linux/notifier.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/mfd/arizona/pdata.h>
@@ -148,8 +149,17 @@ struct arizona {
 	uint16_t dac_comp_coeff;
 	uint8_t dac_comp_enabled;
 	struct mutex dac_comp_lock;
+
+	struct blocking_notifier_head notifier;
 };
 
+static inline int arizona_call_notifiers(struct arizona *arizona,
+					 unsigned long event,
+					 void *data)
+{
+	return blocking_notifier_call_chain(&arizona->notifier, event, data);
+}
+
 int arizona_clk32k_enable(struct arizona *arizona);
 int arizona_clk32k_disable(struct arizona *arizona);
 

sound/soc/codecs/arizona.c

@@ -324,6 +324,17 @@ int arizona_init_gpio(struct snd_soc_codec *codec)
 }
 EXPORT_SYMBOL_GPL(arizona_init_gpio);
 
+int arizona_init_notifiers(struct snd_soc_codec *codec)
+{
+	struct arizona_priv *priv = snd_soc_codec_get_drvdata(codec);
+	struct arizona *arizona = priv->arizona;
+
+	BLOCKING_INIT_NOTIFIER_HEAD(&arizona->notifier);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(arizona_init_notifiers);
+
 const char * const arizona_mixer_texts[ARIZONA_NUM_MIXER_INPUTS] = {
 	"None",
 	"Tone Generator 1",
@@ -2573,6 +2584,30 @@ int arizona_lhpf_coeff_put(struct snd_kcontrol *kcontrol,
 }
 EXPORT_SYMBOL_GPL(arizona_lhpf_coeff_put);
 
+int arizona_register_notifier(struct snd_soc_codec *codec,
+			      struct notifier_block *nb,
+			      int (*notify)(struct notifier_block *nb,
+					    unsigned long action, void *data))
+{
+	struct arizona_priv *priv = snd_soc_codec_get_drvdata(codec);
+	struct arizona *arizona = priv->arizona;
+
+	nb->notifier_call = notify;
+
+	return blocking_notifier_chain_register(&arizona->notifier, nb);
+}
+EXPORT_SYMBOL_GPL(arizona_register_notifier);
+
+int arizona_unregister_notifier(struct snd_soc_codec *codec,
+				struct notifier_block *nb)
+{
+	struct arizona_priv *priv = snd_soc_codec_get_drvdata(codec);
+	struct arizona *arizona = priv->arizona;
+
+	return blocking_notifier_chain_unregister(&arizona->notifier, nb);
+}
+EXPORT_SYMBOL_GPL(arizona_unregister_notifier);
+
 MODULE_DESCRIPTION("ASoC Wolfson Arizona class device support");
 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 MODULE_LICENSE("GPL");

sound/soc/codecs/arizona.h

@@ -306,6 +306,7 @@ extern int arizona_set_fll(struct arizona_fll *fll, int source,
 extern int arizona_init_spk(struct snd_soc_codec *codec);
 extern int arizona_init_gpio(struct snd_soc_codec *codec);
 extern int arizona_init_mono(struct snd_soc_codec *codec);
+extern int arizona_init_notifiers(struct snd_soc_codec *codec);
 
 extern int arizona_free_spk(struct snd_soc_codec *codec);
 
@@ -317,4 +318,13 @@ int arizona_set_output_mode(struct snd_soc_codec *codec, int output,
 extern bool arizona_input_analog(struct snd_soc_codec *codec, int shift);
 
 extern const char *arizona_sample_rate_val_to_name(unsigned int rate_val);
+
+extern int arizona_register_notifier(struct snd_soc_codec *codec,
+				     struct notifier_block *nb,
+				     int (*notify)(struct notifier_block *nb,
+						   unsigned long action,
+						   void *data));
+extern int arizona_unregister_notifier(struct snd_soc_codec *codec,
+				       struct notifier_block *nb);
+
 #endif

sound/soc/codecs/cs47l24.c

@@ -1096,6 +1096,7 @@ static int cs47l24_codec_probe(struct snd_soc_codec *codec)
 	arizona_init_spk(codec);
 	arizona_init_gpio(codec);
 	arizona_init_mono(codec);
+	arizona_init_notifiers(codec);
 
 	ret = arizona_request_irq(arizona, ARIZONA_IRQ_DSP_IRQ1,
 				  "ADSP2 Compressed IRQ", cs47l24_adsp2_irq,

sound/soc/codecs/wm5110.c

@@ -2251,6 +2251,7 @@ static int wm5110_codec_probe(struct snd_soc_codec *codec)
 	arizona_init_spk(codec);
 	arizona_init_gpio(codec);
 	arizona_init_mono(codec);
+	arizona_init_notifiers(codec);
 
 	ret = arizona_request_irq(arizona, ARIZONA_IRQ_DSP_IRQ1,
 				  "ADSP2 Compressed IRQ", wm5110_adsp2_irq,