soc: swr-mstr: Add support to listen for DC detection

Add support to listen for DC detection event.
Shutdown WSA on receiving DC detection event.
Porting the changes from old master driver to new driver.

Change-Id: I4d323bb8074d447b2969dd01c7129e57160b6c04
Signed-off-by: Ramprasad Katkam <[email protected]>

soc/swr-mstr-ctrl.c

@@ -27,6 +27,7 @@
 #include <soc/soundwire.h>
 #include <soc/swr-wcd.h>
 #include <linux/regmap.h>
+#include <dsp/msm-audio-event-notify.h>
 #include "swrm_registers.h"
 #include "swr-mstr-ctrl.h"
 #include "swrm_port_config.h"
@@ -1423,6 +1424,33 @@ static int swrm_master_init(struct swr_mstr_ctrl *swrm)
 	return ret;
 }
 
+static int swrm_event_notify(struct notifier_block *self,
+				unsigned long action, void *data)
+{
+	struct swr_mstr_ctrl *swrm = container_of(self, struct swr_mstr_ctrl,
+							event_notifier);
+	if (!swrm || !swrm->pdev) {
+		pr_err("%s: swrm or pdev is NULL\n", __func__);
+		return -EINVAL;
+	}
+	if (action != MSM_AUD_DC_EVENT) {
+		dev_err(&swrm->pdev->dev, "%s: invalid event type: %lu\n",
+			__func__, action);
+		return -EINVAL;
+	}
+
+	schedule_work(&(swrm->dc_presence_work));
+
+	return 0;
+}
+
+static void swrm_notify_work_fn(struct work_struct *work)
+{
+	struct swr_mstr_ctrl *swrm = container_of(work, struct swr_mstr_ctrl,
+							dc_presence_work);
+	swrm_wcd_notify(swrm->pdev, SWR_DEVICE_DOWN, NULL);
+}
+
 static int swrm_probe(struct platform_device *pdev)
 {
 	struct swr_mstr_ctrl *swrm;
@@ -1671,6 +1699,10 @@ static int swrm_probe(struct platform_device *pdev)
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_mark_last_busy(&pdev->dev);
 
+	INIT_WORK(&swrm->dc_presence_work, swrm_notify_work_fn);
+	swrm->event_notifier.notifier_call  = swrm_event_notify;
+	msm_aud_evt_register_client(&swrm->event_notifier);
+
 	return 0;
 err_mstr_fail:
 	if (swrm->reg_irq)
@@ -1700,6 +1732,7 @@ static int swrm_remove(struct platform_device *pdev)
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);
 	swr_unregister_master(&swrm->master);
+	msm_aud_evt_unregister_client(&swrm->event_notifier);
 	mutex_destroy(&swrm->mlock);
 	mutex_destroy(&swrm->reslock);
 	mutex_destroy(&swrm->force_down_lock);

soc/swr-mstr-ctrl.h

@@ -139,6 +139,8 @@ struct swr_mstr_ctrl {
 	u8 num_cfg_devs;
 	struct mutex force_down_lock;
 	int force_down_state;
+	struct notifier_block event_notifier;
+	struct work_struct dc_presence_work;
 	u8 num_ports;
 	struct swrm_port_type
 			port_mapping[SWR_MSTR_PORT_LEN][SWR_MAX_CH_PER_PORT];