drm/amd/display: Handle Content protection property changes

[Why]
We need to manage the content protection property changes for
different usecase, once cp is DESIRED we need to maintain the
ENABLED/DESIRED status for different cases.

[How]
1. Attach the content_protection property

2. HDCP enable (UNDESIRED -> DESIRED)
	call into the module with the correct parameters to start
	hdcp. Set cp to ENABLED

3. HDCP disable (ENABLED -> UNDESIRED)
	Call the module to disable hdcp.

3. Handle Special cases	(Hotplug, S3, headless S3, DPMS)
	If already ENABLED: set to DESIRED on unplug/suspend/dpms,
	and disable hdcp

	Then on plugin/resume/dpms: enable HDCP
Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -70,6 +70,7 @@
 #include <drm/drm_edid.h>
 #include <drm/drm_vblank.h>
 #include <drm/drm_audio_component.h>
+#include <drm/drm_hdcp.h>
 
 #if defined(CONFIG_DRM_AMD_DC_DCN1_0)
 #include "ivsrcid/dcn/irqsrcs_dcn_1_0.h"
@@ -1475,6 +1476,11 @@ amdgpu_dm_update_connector_after_detect(struct amdgpu_dm_connector *aconnector)
 		dc_sink_release(aconnector->dc_sink);
 		aconnector->dc_sink = NULL;
 		aconnector->edid = NULL;
+#ifdef CONFIG_DRM_AMD_DC_HDCP
+		/* Set CP to DESIRED if it was ENABLED, so we can re-enable it again on hotplug */
+		if (connector->state->content_protection == DRM_MODE_CONTENT_PROTECTION_ENABLED)
+			connector->state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+#endif
 	}
 
 	mutex_unlock(&dev->mode_config.mutex);
@@ -1489,6 +1495,9 @@ static void handle_hpd_irq(void *param)
 	struct drm_connector *connector = &aconnector->base;
 	struct drm_device *dev = connector->dev;
 	enum dc_connection_type new_connection_type = dc_connection_none;
+#ifdef CONFIG_DRM_AMD_DC_HDCP
+	struct amdgpu_device *adev = dev->dev_private;
+#endif
 
 	/*
 	 * In case of failure or MST no need to update connector status or notify the OS
@@ -1496,6 +1505,9 @@ static void handle_hpd_irq(void *param)
 	 */
 	mutex_lock(&aconnector->hpd_lock);
 
+#ifdef CONFIG_DRM_AMD_DC_HDCP
+	hdcp_reset_display(adev->dm.hdcp_workqueue, aconnector->dc_link->link_index);
+#endif
 	if (aconnector->fake_enable)
 		aconnector->fake_enable = false;
 
@@ -5124,6 +5136,9 @@ void amdgpu_dm_connector_init_helper(struct amdgpu_display_manager *dm,
 
 		drm_connector_attach_vrr_capable_property(
 			&aconnector->base);
+#ifdef CONFIG_DRM_AMD_DC_HDCP
+		drm_connector_attach_content_protection_property(&aconnector->base, false);
+#endif
 	}
 }
 
@@ -5366,6 +5381,63 @@ is_scaling_state_different(const struct dm_connector_state *dm_state,
 	return false;
 }
 
+#ifdef CONFIG_DRM_AMD_DC_HDCP
+static bool is_content_protection_different(struct drm_connector_state *state,
+					    const struct drm_connector_state *old_state,
+					    const struct drm_connector *connector, struct hdcp_workqueue *hdcp_w)
+{
+	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
+
+	/* CP is being re enabled, ignore this */
+	if (old_state->content_protection == DRM_MODE_CONTENT_PROTECTION_ENABLED &&
+	    state->content_protection == DRM_MODE_CONTENT_PROTECTION_DESIRED) {
+		state->content_protection = DRM_MODE_CONTENT_PROTECTION_ENABLED;
+		return false;
+	}
+
+	/* S3 resume case, since old state will always be 0 (UNDESIRED) and the restored state will be ENABLED */
+	if (old_state->content_protection == DRM_MODE_CONTENT_PROTECTION_UNDESIRED &&
+	    state->content_protection == DRM_MODE_CONTENT_PROTECTION_ENABLED)
+		state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+
+	/* Check if something is connected/enabled, otherwise we start hdcp but nothing is connected/enabled
+	 * hot-plug, headless s3, dpms
+	 */
+	if (state->content_protection == DRM_MODE_CONTENT_PROTECTION_DESIRED && connector->dpms == DRM_MODE_DPMS_ON &&
+	    aconnector->dc_sink != NULL)
+		return true;
+
+	if (old_state->content_protection == state->content_protection)
+		return false;
+
+	if (state->content_protection == DRM_MODE_CONTENT_PROTECTION_UNDESIRED)
+		return true;
+
+	return false;
+}
+
+static void update_content_protection(struct drm_connector_state *state, const struct drm_connector *connector,
+				      struct hdcp_workqueue *hdcp_w)
+{
+	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
+
+	if (state->content_protection == DRM_MODE_CONTENT_PROTECTION_DESIRED) {
+		hdcp_add_display(hdcp_w, aconnector->dc_link->link_index);
+
+		/*
+		 * TODO: ENABLED should be verified using psp, it is planned later.
+		 * Just set this to ENABLED for now
+		 */
+		state->content_protection = DRM_MODE_CONTENT_PROTECTION_ENABLED;
+
+		return;
+	}
+
+	if (state->content_protection == DRM_MODE_CONTENT_PROTECTION_UNDESIRED)
+		hdcp_remove_display(hdcp_w, aconnector->dc_link->link_index, aconnector->base.index);
+
+}
+#endif
 static void remove_stream(struct amdgpu_device *adev,
 			  struct amdgpu_crtc *acrtc,
 			  struct dc_stream_state *stream)
@@ -6290,6 +6362,30 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 				acrtc->otg_inst = status->primary_otg_inst;
 		}
 	}
+#ifdef CONFIG_DRM_AMD_DC_HDCP
+	for_each_oldnew_connector_in_state(state, connector, old_con_state, new_con_state, i) {
+		struct dm_connector_state *dm_new_con_state = to_dm_connector_state(new_con_state);
+		struct amdgpu_crtc *acrtc = to_amdgpu_crtc(dm_new_con_state->base.crtc);
+		struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
+
+		new_crtc_state = NULL;
+
+		if (acrtc)
+			new_crtc_state = drm_atomic_get_new_crtc_state(state, &acrtc->base);
+
+		dm_new_crtc_state = to_dm_crtc_state(new_crtc_state);
+
+		if (dm_new_crtc_state && dm_new_crtc_state->stream == NULL &&
+		    connector->state->content_protection == DRM_MODE_CONTENT_PROTECTION_ENABLED) {
+			hdcp_reset_display(adev->dm.hdcp_workqueue, aconnector->dc_link->link_index);
+			new_con_state->content_protection = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+			continue;
+		}
+
+		if (is_content_protection_different(new_con_state, old_con_state, connector, adev->dm.hdcp_workqueue))
+			update_content_protection(new_con_state, connector, adev->dm.hdcp_workqueue);
+	}
+#endif
 
 	/* Handle connector state changes */
 	for_each_oldnew_connector_in_state(state, connector, old_con_state, new_con_state, i) {