MLK-24611-2: drm: bridge: cdns: Add callback function for plug/unplug event

cdns-hdmi-core exports a function cdns_hdmi_set_plugged_cb so
platform device can register the callback

implement hook_plugged_cb to register callback function for hdmi cable
plug/unplug event.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Sandor Yu <Sandor.yu@nxp.com>

drivers/gpu/drm/bridge/cadence/cdns-hdmi-core.c

@@ -225,11 +225,35 @@ void cdns_hdmi_mode_set(struct cdns_mhdp_device *mhdp)
 	}
 }
 
+static void handle_plugged_change(struct cdns_mhdp_device *mhdp, bool plugged)
+{
+	if (mhdp->plugged_cb && mhdp->codec_dev)
+		mhdp->plugged_cb(mhdp->codec_dev, plugged);
+}
+
+int cdns_hdmi_set_plugged_cb(struct cdns_mhdp_device *mhdp,
+			     hdmi_codec_plugged_cb fn,
+			     struct device *codec_dev)
+{
+	bool plugged;
+
+	mutex_lock(&mhdp->lock);
+	mhdp->plugged_cb = fn;
+	mhdp->codec_dev = codec_dev;
+	plugged = mhdp->last_connector_result == connector_status_connected;
+	handle_plugged_change(mhdp, plugged);
+	mutex_unlock(&mhdp->lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(cdns_hdmi_set_plugged_cb);
+
 static enum drm_connector_status
 cdns_hdmi_connector_detect(struct drm_connector *connector, bool force)
 {
 	struct cdns_mhdp_device *mhdp =
 				container_of(connector, struct cdns_mhdp_device, connector.base);
+	enum drm_connector_status result;
 
 	u8 hpd = 0xf;
 
@@ -237,15 +261,25 @@ cdns_hdmi_connector_detect(struct drm_connector *connector, bool force)
 
 	if (hpd == 1)
 		/* Cable Connected */
-		return connector_status_connected;
+		result = connector_status_connected;
 	else if (hpd == 0)
 		/* Cable Disconnedted */
-		return connector_status_disconnected;
+		result = connector_status_disconnected;
 	else {
 		/* Cable status unknown */
 		DRM_INFO("Unknow cable status, hdp=%u\n", hpd);
-		return connector_status_unknown;
+		result = connector_status_unknown;
 	}
+
+	mutex_lock(&mhdp->lock);
+	if (result != mhdp->last_connector_result) {
+		handle_plugged_change(mhdp,
+				      result == connector_status_connected);
+		mhdp->last_connector_result = result;
+	}
+	mutex_unlock(&mhdp->lock);
+
+	return result;
 }
 
 static int cdns_hdmi_connector_get_modes(struct drm_connector *connector)
@@ -608,6 +642,7 @@ static int __cdns_hdmi_probe(struct platform_device *pdev,
 #ifdef CONFIG_OF
 	mhdp->bridge.base.of_node = dev->of_node;
 #endif
+	mhdp->last_connector_result = connector_status_disconnected;
 
 	memset(&pdevinfo, 0, sizeof(pdevinfo));
 	pdevinfo.parent = dev;

drivers/gpu/drm/bridge/cadence/cdns-mhdp-audio.c

@@ -380,11 +380,21 @@ static int audio_get_eld(struct device *dev, void *data,
 	return 0;
 }
 
+static int audio_hook_plugged_cb(struct device *dev, void *data,
+				 hdmi_codec_plugged_cb fn,
+				 struct device *codec_dev)
+{
+	struct cdns_mhdp_device *mhdp = dev_get_drvdata(dev);
+
+	return cdns_hdmi_set_plugged_cb(mhdp, fn, codec_dev);
+}
+
 static const struct hdmi_codec_ops audio_codec_ops = {
 	.hw_params = audio_hw_params,
 	.audio_shutdown = audio_shutdown,
 	.digital_mute = audio_digital_mute,
 	.get_eld = audio_get_eld,
+	.hook_plugged_cb = audio_hook_plugged_cb,
 };
 
 int cdns_mhdp_register_audio_driver(struct device *dev)

include/drm/bridge/cdns-mhdp.h

@@ -22,6 +22,7 @@
 #include <drm/drm_dp_mst_helper.h>
 #include <media/cec.h>
 #include <linux/bitops.h>
+#include <sound/hdmi-codec.h>
 
 #define ADDR_IMEM		0x10000
 #define ADDR_DMEM		0x20000
@@ -714,6 +715,9 @@ struct cdns_mhdp_device {
 	};
 	const struct cdns_plat_data *plat_data;
 
+	hdmi_codec_plugged_cb plugged_cb;
+	struct device *codec_dev;
+	enum drm_connector_status last_connector_result;
 };
 
 u32 cdns_mhdp_bus_read(struct cdns_mhdp_device *mhdp, u32 offset);
@@ -796,6 +800,8 @@ void cdns_dp_remove(struct platform_device *pdev);
 void cdns_dp_unbind(struct device *dev);
 int cdns_dp_bind(struct platform_device *pdev,
 			struct drm_encoder *encoder, struct cdns_mhdp_device *mhdp);
+int cdns_hdmi_set_plugged_cb(struct cdns_mhdp_device *mhdp, hdmi_codec_plugged_cb fn,
+			     struct device *codec_dev);
 
 /* CEC */
 #ifdef CONFIG_DRM_CDNS_HDMI_CEC