[PATCH 8/9] usb: typec: altmodes/displayport: Notify drm subsys of hotplug events

[Hans de Goede <hdegoede@redhat.com>]

Use the new drm_connector_find_by_fwnode() and
drm_connector_oob_hotplug_event() functions to let drm/kms drivers
know about DisplayPort over Type-C hotplug events.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
- Add missing depends on DRM to TYPEC_DP_ALTMODE Kconfig entry
---
 drivers/usb/typec/altmodes/Kconfig       |  1 +
 drivers/usb/typec/altmodes/displayport.c | 40 +++++++++++++++++++++++-
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/altmodes/Kconfig b/drivers/usb/typec/altmodes/Kconfig
index 60d375e9c3c7..1a6b5e872b0d 100644
--- a/drivers/usb/typec/altmodes/Kconfig
+++ b/drivers/usb/typec/altmodes/Kconfig
@@ -4,6 +4,7 @@ menu "USB Type-C Alternate Mode drivers"
 
 config TYPEC_DP_ALTMODE
 	tristate "DisplayPort Alternate Mode driver"
+	depends on DRM
 	help
 	  DisplayPort USB Type-C Alternate Mode allows DisplayPort
 	  displays and adapters to be attached to the USB Type-C
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index aa669b9cf70e..f00dfc5c14b6 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -11,8 +11,10 @@
 #include <linux/delay.h>
 #include <linux/mutex.h>
 #include <linux/module.h>
+#include <linux/property.h>
 #include <linux/usb/pd_vdo.h>
 #include <linux/usb/typec_dp.h>
+#include <drm/drm_connector.h>
 #include "displayport.h"
 
 #define DP_HEADER(_dp, ver, cmd)	(VDO((_dp)->alt->svid, 1, ver, cmd)	\
@@ -62,12 +64,30 @@ struct dp_altmode {
 	struct work_struct work;
 	struct typec_altmode *alt;
 	const struct typec_altmode *port;
+	struct fwnode_handle *connector_fwnode;
 };
 
+static void dp_altmode_notify_connector(struct dp_altmode *dp)
+{
+	struct drm_connector_oob_hotplug_event_data data = { };
+	u8 pin_assign = DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
+
+	data.connected = dp->data.status & DP_STATUS_HPD_STATE;
+	data.orientation = typec_altmode_get_orientation(dp->alt);
+
+	if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK)
+		data.dp_lanes = 4;
+	else if (pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
+		data.dp_lanes = 2;
+
+	drm_connector_oob_hotplug_event(dp->connector_fwnode, &data);
+}
+
 static int dp_altmode_notify(struct dp_altmode *dp)
 {
 	unsigned long conf;
 	u8 state;
+	int ret;
 
 	if (dp->data.conf) {
 		state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
@@ -76,7 +96,12 @@ static int dp_altmode_notify(struct dp_altmode *dp)
 		conf = TYPEC_STATE_USB;
 	}
 
-	return typec_altmode_notify(dp->alt, conf, &dp->data);
+	ret = typec_altmode_notify(dp->alt, conf, &dp->data);
+	if (ret)
+		return ret;
+
+	dp_altmode_notify_connector(dp);
+	return 0;
 }
 
 static int dp_altmode_configure(struct dp_altmode *dp, u8 con)
@@ -512,6 +537,7 @@ static const struct attribute_group dp_altmode_group = {
 int dp_altmode_probe(struct typec_altmode *alt)
 {
 	const struct typec_altmode *port = typec_altmode_get_partner(alt);
+	struct fwnode_handle *fwnode;
 	struct dp_altmode *dp;
 	int ret;
 
@@ -540,6 +566,11 @@ int dp_altmode_probe(struct typec_altmode *alt)
 	alt->desc = "DisplayPort";
 	alt->ops = &dp_altmode_ops;
 
+	fwnode = dev_fwnode(alt->dev.parent->parent); /* typec_port fwnode */
+	dp->connector_fwnode = fwnode_find_reference(fwnode, "displayport", 0);
+	if (IS_ERR(dp->connector_fwnode))
+		dp->connector_fwnode = NULL;
+
 	typec_altmode_set_drvdata(alt, dp);
 
 	dp->state = DP_STATE_ENTER;
@@ -555,6 +586,13 @@ void dp_altmode_remove(struct typec_altmode *alt)
 
 	sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group);
 	cancel_work_sync(&dp->work);
+
+	if (dp->connector_fwnode) {
+		dp->data.conf = 0;
+		dp->data.status = 0;
+		dp_altmode_notify_connector(dp);
+		fwnode_handle_put(dp->connector_fwnode);
+	}
 }
 EXPORT_SYMBOL_GPL(dp_altmode_remove);
 
-- 
2.31.1