disp: msm: dp: add support for Trusted UI transitions

We add support for Trusted UI (TUI) transitions and address the
following use cases:

1. Display was active before TUI start
    - Power off on TUI start, power off on TUI stop
    - Register access not allowed after TUI start (skip all
      events except disconnect)
2. Hotplug while TUI is active
    - Connect: skip sending connect uevent
    - Disconnect: send disconnect uevent and skip any controller
      programming
3. TUI start while processing HPD High
    - Complete all connect work (and therefore any register access)
      then send connect uevent
4. Audio
    - Disable audio at TUI start and skip audio programming if TUI
      is active

Change-Id: I553e5fa9f3b8265dd0410bf2d616a9accf90605f
Signed-off-by: Tatenda Chipeperekwa <tatendac@codeaurora.org>

msm/dp/dp_audio.c

@@ -397,6 +397,11 @@ static int dp_audio_info_setup(struct platform_device *pdev,
 		return rc;
 	}
 
+	if (audio->dp_audio.tui_active) {
+		DP_DEBUG("TUI session active\n");
+		return 0;
+	}
+
 	mutex_lock(&audio->ops_lock);
 
 	audio->channels = params->num_of_channels;
@@ -495,6 +500,11 @@ static void dp_audio_teardown_done(struct platform_device *pdev)
 	if (IS_ERR(audio))
 		return;
 
+	if (audio->dp_audio.tui_active) {
+		DP_DEBUG("TUI session active\n");
+		return;
+	}
+
 	mutex_lock(&audio->ops_lock);
 	dp_audio_enable(audio, false);
 	mutex_unlock(&audio->ops_lock);