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

[Hans de Goede]

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

Reviewed-by: Heikki Krogerus <heikki.kroge...@linux.intel.com>
Tested-by: Heikki Krogerus <heikki.kroge...@linux.intel.com>
Signed-off-by: Hans de Goede <hdego...@redhat.com>
---
Changes in v3:
- Only call drm_connector_oob_hotplug_event() on hpd status bit change
- Adjust for drm_connector_oob_hotplug_event() no longer having a data
  argument

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 | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

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..c1d8c23baa39 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)     
\
@@ -57,11 +59,13 @@ struct dp_altmode {
        struct typec_displayport_data data;
 
        enum dp_state state;
+       bool hpd;
 
        struct mutex lock; /* device lock */
        struct work_struct work;
        struct typec_altmode *alt;
        const struct typec_altmode *port;
+       struct fwnode_handle *connector_fwnode;
 };
 
 static int dp_altmode_notify(struct dp_altmode *dp)
@@ -125,6 +129,7 @@ static int dp_altmode_configure(struct dp_altmode *dp, u8 
con)
 static int dp_altmode_status_update(struct dp_altmode *dp)
 {
        bool configured = !!DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
+       bool hpd = !!(dp->data.status & DP_STATUS_HPD_STATE);
        u8 con = DP_STATUS_CONNECTION(dp->data.status);
        int ret = 0;
 
@@ -137,6 +142,11 @@ static int dp_altmode_status_update(struct dp_altmode *dp)
                ret = dp_altmode_configure(dp, con);
                if (!ret)
                        dp->state = DP_STATE_CONFIGURE;
+       } else {
+               if (dp->hpd != hpd) {
+                       drm_connector_oob_hotplug_event(dp->connector_fwnode);
+                       dp->hpd = hpd;
+               }
        }
 
        return ret;
@@ -512,6 +522,7 @@ 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 +551,11 @@ 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 +571,13 @@ 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) {
+               if (dp->hpd)
+                       drm_connector_oob_hotplug_event(dp->connector_fwnode);
+
+               fwnode_handle_put(dp->connector_fwnode);
+       }
 }
 EXPORT_SYMBOL_GPL(dp_altmode_remove);
 
-- 
2.31.1