drm/bridge: display-connector: detect DP state if cable is plugged on boot (#397)

drm/bridge: display-connector: detect DP state if cable is plugged on boot

Author: sgaud-quic

drivers/gpu/drm/bridge/display-connector.c

@@ -12,6 +12,7 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
+#include <linux/workqueue.h>
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
@@ -25,6 +26,8 @@ struct display_connector {
 
 	struct regulator	*supply;
 	struct gpio_desc	*ddc_en;
+
+	struct work_struct	hpd_work;
 };
 
 static inline struct display_connector *
@@ -87,6 +90,34 @@ display_connector_bridge_detect(struct drm_bridge *bridge, struct drm_connector
 	return display_connector_detect(bridge);
 }
 
+static void display_connector_hpd_enable(struct drm_bridge *bridge)
+{
+	struct display_connector *conn = to_display_connector(bridge);
+
+	enable_irq(conn->hpd_irq);
+
+	if (conn->bridge.type == DRM_MODE_CONNECTOR_DisplayPort)
+		schedule_work(&conn->hpd_work);
+}
+
+static void display_connector_hpd_disable(struct drm_bridge *bridge)
+{
+	struct display_connector *conn = to_display_connector(bridge);
+
+	if (conn->bridge.type == DRM_MODE_CONNECTOR_DisplayPort)
+		cancel_work_sync(&conn->hpd_work);
+
+	disable_irq(conn->hpd_irq);
+}
+
+static void display_connector_hpd_work(struct work_struct *work)
+{
+	struct display_connector *conn = container_of(work, struct display_connector, hpd_work);
+	struct drm_bridge *bridge = &conn->bridge;
+
+	drm_bridge_hpd_notify(bridge, display_connector_detect(bridge));
+}
+
 static const struct drm_edid *display_connector_edid_read(struct drm_bridge *bridge,
 							  struct drm_connector *connector)
 {
@@ -178,6 +209,8 @@ static u32 *display_connector_get_input_bus_fmts(struct drm_bridge *bridge,
 static const struct drm_bridge_funcs display_connector_bridge_funcs = {
 	.attach = display_connector_attach,
 	.detect = display_connector_bridge_detect,
+	.hpd_enable = display_connector_hpd_enable,
+	.hpd_disable = display_connector_hpd_disable,
 	.edid_read = display_connector_edid_read,
 	.atomic_get_output_bus_fmts = display_connector_get_output_bus_fmts,
 	.atomic_get_input_bus_fmts = display_connector_get_input_bus_fmts,
@@ -307,6 +340,7 @@ static int display_connector_probe(struct platform_device *pdev)
 						NULL, display_connector_hpd_irq,
 						IRQF_TRIGGER_RISING |
 						IRQF_TRIGGER_FALLING |
+						IRQF_NO_AUTOEN |
 						IRQF_ONESHOT,
 						"HPD", conn);
 		if (ret) {
@@ -378,6 +412,8 @@ static int display_connector_probe(struct platform_device *pdev)
 		conn->bridge.ops |= DRM_BRIDGE_OP_DETECT;
 	if (conn->hpd_irq >= 0)
 		conn->bridge.ops |= DRM_BRIDGE_OP_HPD;
+	if (conn->hpd_irq >= 0 && type == DRM_MODE_CONNECTOR_DisplayPort)
+		INIT_WORK(&conn->hpd_work, display_connector_hpd_work);
 
 	dev_dbg(&pdev->dev,
 		"Found %s display connector '%s' %s DDC bus and %s HPD GPIO (ops 0x%x)\n",