dsp: add audio event notifier support

Add support for audio event notifier framework to
send/receive events across audio drivers.

CRs-Fixed: 2244131
Change-Id: I1e36703a91625cd52333596d66dc21a0e8876738
Signed-off-by: Vidyakumar Athota <[email protected]>
Signed-off-by: Vignesh Kulothungan <[email protected]>

dsp/Kbuild

@@ -75,6 +75,7 @@ COMMON_INC :=	-I$(AUDIO_ROOT)/$(COMMON_DIR)
 ############ QDSP6V2 ############
 
 ifdef CONFIG_SND_SOC_MSM_QDSP6V2_INTF
+	Q6_OBJS += msm-audio-event-notify.o
 	Q6_OBJS += audio_calibration.o
 	Q6_OBJS += audio_cal_utils.o
 	Q6_OBJS += q6adm.o

dsp/msm-audio-event-notify.c

@@ -0,0 +1,45 @@
+/* Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <dsp/msm-audio-event-notify.h>
+#include <linux/export.h>
+
+static ATOMIC_NOTIFIER_HEAD(msm_aud_evt_notifier_list);
+
+/**
+ *	msm_aud_evt_register_client - register a client notifier
+ *	@nb: notifier block to callback on events
+ */
+int msm_aud_evt_register_client(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&msm_aud_evt_notifier_list, nb);
+}
+EXPORT_SYMBOL(msm_aud_evt_register_client);
+
+/**
+ *	msm_aud_evt_unregister_client - unregister a client notifier
+ *	@nb: notifier block to callback on events
+ */
+int msm_aud_evt_unregister_client(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&msm_aud_evt_notifier_list, nb);
+}
+EXPORT_SYMBOL(msm_aud_evt_unregister_client);
+
+/**
+ * msm_aud_evt_notifier_call_chain - notify clients of fb_events
+ *
+ */
+int msm_aud_evt_notifier_call_chain(unsigned long val, void *v)
+{
+	return atomic_notifier_call_chain(&msm_aud_evt_notifier_list, val, v);
+}
+EXPORT_SYMBOL_GPL(msm_aud_evt_notifier_call_chain);

include/dsp/msm-audio-event-notify.h

@@ -0,0 +1,44 @@
+/* Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef __MSM_AUDIO_EVENT_NOTIFY_H_
+#define __MSM_AUDIO_EVENT_NOTIFY_H_
+
+#include <linux/notifier.h>
+
+#if IS_ENABLED(CONFIG_SND_SOC_MSM_QDSP6V2_INTF)
+int msm_aud_evt_register_client(struct notifier_block *nb);
+int msm_aud_evt_unregister_client(struct notifier_block *nb);
+int msm_aud_evt_notifier_call_chain(unsigned long val, void *v);
+#else
+static inline int msm_aud_evt_register_client(struct notifier_block *nb)
+{
+	return -ENOSYS;
+}
+
+static inline int msm_aud_evt_unregister_client(struct notifier_block *nb)
+{
+	return -ENOSYS;
+}
+
+static inline int msm_aud_evt_notifier_call_chain(unsigned long val, void *v)
+{
+	return -ENOSYS;
+}
+#endif
+
+enum {
+	MSM_AUD_DC_EVENT = 1,
+};
+
+#endif