drm/bridge:anx7625: Update HDCP content status

When user enabled HDCP feature, userspace will set HDCP content
to DRM_MODE_CONTENT_PROTECTION_DESIRED. Next, anx7625 will update
HDCP content to DRM_MODE_CONTENT_PROTECTION_ENABLED if down stream
support HDCP feature.

As anx7625 bridge IC will be power down after call .atomic_disable(),
then all HDCP status will be lost on chip. So we should reestablish
HDCP again in .atomic_enable(), and update hdcp content to DESIRE if
current HDCP content is ENABLE in .atomic_disable().

v4:
 - Change HDCP content value to DESIRED if HDCP status is ENABLE in bridge
interface .atomic_enable().

v3:
 - Move hdcp content value checking from bridge interface
.atomic_check() to .atomic_enable()

v2:
 - Add more details in commit message

Signed-off-by: Xin Ji <xji@analogixsemi.com>
Tested-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20241219070330.224996-1-xji@analogixsemi.com


Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241219070330.224996-1-xji@analogixsemi.com

drivers/gpu/drm/bridge/analogix/anx7625.c

@@ -2139,49 +2139,6 @@ static void hdcp_check_work_func(struct work_struct *work)
 	drm_modeset_unlock(&drm_dev->mode_config.connection_mutex);
 }
 
-static int anx7625_connector_atomic_check(struct anx7625_data *ctx,
-					  struct drm_connector_state *state)
-{
-	struct device *dev = ctx->dev;
-	int cp;
-
-	dev_dbg(dev, "hdcp state check\n");
-	cp = state->content_protection;
-
-	if (cp == ctx->hdcp_cp)
-		return 0;
-
-	if (cp == DRM_MODE_CONTENT_PROTECTION_DESIRED) {
-		if (ctx->dp_en) {
-			dev_dbg(dev, "enable HDCP\n");
-			anx7625_hdcp_enable(ctx);
-
-			queue_delayed_work(ctx->hdcp_workqueue,
-					   &ctx->hdcp_work,
-					   msecs_to_jiffies(2000));
-		}
-	}
-
-	if (cp == DRM_MODE_CONTENT_PROTECTION_UNDESIRED) {
-		if (ctx->hdcp_cp != DRM_MODE_CONTENT_PROTECTION_ENABLED) {
-			dev_err(dev, "current CP is not ENABLED\n");
-			return -EINVAL;
-		}
-		anx7625_hdcp_disable(ctx);
-		ctx->hdcp_cp = DRM_MODE_CONTENT_PROTECTION_UNDESIRED;
-		drm_hdcp_update_content_protection(ctx->connector,
-						   ctx->hdcp_cp);
-		dev_dbg(dev, "update CP to UNDESIRE\n");
-	}
-
-	if (cp == DRM_MODE_CONTENT_PROTECTION_ENABLED) {
-		dev_err(dev, "Userspace illegal set to PROTECTION ENABLE\n");
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
 static int anx7625_bridge_attach(struct drm_bridge *bridge,
 				 enum drm_bridge_attach_flags flags)
 {
@@ -2418,7 +2375,7 @@ static int anx7625_bridge_atomic_check(struct drm_bridge *bridge,
 	anx7625_bridge_mode_fixup(bridge, &crtc_state->mode,
 				  &crtc_state->adjusted_mode);
 
-	return anx7625_connector_atomic_check(ctx, conn_state);
+	return 0;
 }
 
 static void anx7625_bridge_atomic_enable(struct drm_bridge *bridge,
@@ -2427,6 +2384,7 @@ static void anx7625_bridge_atomic_enable(struct drm_bridge *bridge,
 	struct anx7625_data *ctx = bridge_to_anx7625(bridge);
 	struct device *dev = ctx->dev;
 	struct drm_connector *connector;
+	struct drm_connector_state *conn_state;
 
 	dev_dbg(dev, "drm atomic enable\n");
 
@@ -2441,6 +2399,22 @@ static void anx7625_bridge_atomic_enable(struct drm_bridge *bridge,
 	_anx7625_hpd_polling(ctx, 5000 * 100);
 
 	anx7625_dp_start(ctx);
+
+	conn_state = drm_atomic_get_new_connector_state(state->base.state, connector);
+
+	if (WARN_ON(!conn_state))
+		return;
+
+	if (conn_state->content_protection == DRM_MODE_CONTENT_PROTECTION_DESIRED) {
+		if (ctx->dp_en) {
+			dev_dbg(dev, "enable HDCP\n");
+			anx7625_hdcp_enable(ctx);
+
+			queue_delayed_work(ctx->hdcp_workqueue,
+					   &ctx->hdcp_work,
+					   msecs_to_jiffies(2000));
+		}
+	}
 }
 
 static void anx7625_bridge_atomic_disable(struct drm_bridge *bridge,
@@ -2451,6 +2425,17 @@ static void anx7625_bridge_atomic_disable(struct drm_bridge *bridge,
 
 	dev_dbg(dev, "drm atomic disable\n");
 
+	flush_workqueue(ctx->hdcp_workqueue);
+
+	if (ctx->connector &&
+	    ctx->hdcp_cp == DRM_MODE_CONTENT_PROTECTION_ENABLED) {
+		anx7625_hdcp_disable(ctx);
+		ctx->hdcp_cp = DRM_MODE_CONTENT_PROTECTION_DESIRED;
+		drm_hdcp_update_content_protection(ctx->connector,
+						   ctx->hdcp_cp);
+		dev_dbg(dev, "update CP to DESIRE\n");
+	}
+
 	ctx->connector = NULL;
 	anx7625_dp_stop(ctx);