[PATCH v2 16/16] drm/vkms: Allow to configure connector status via configfs

["José Expósito" <jose.exposito89@gmail.com>]

When a connector is created, add a `status` file to allow to update the
connector status to:

 - 1 connector_status_connected
 - 2 connector_status_disconnected
 - 3 connector_status_unknown

If the device is enabled, updating the status hot-plug or unplugs the
connector.

Signed-off-by: José Expósito <jose.exposito89@gmail.com>
---
 Documentation/gpu/vkms.rst            |  5 +++
 drivers/gpu/drm/vkms/vkms_configfs.c  | 46 +++++++++++++++++++++++++++
 drivers/gpu/drm/vkms/vkms_connector.c |  7 ++++
 drivers/gpu/drm/vkms/vkms_connector.h |  6 ++++
 4 files changed, 64 insertions(+)

diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst
index c551241fe873..7c54099b1dc6 100644
--- a/Documentation/gpu/vkms.rst
+++ b/Documentation/gpu/vkms.rst
@@ -108,6 +108,11 @@ Last but not least, create one or more connectors::
 
   sudo mkdir /config/vkms/my-vkms/connectors/connector0
 
+Connectors have 1 configurable attribute:
+
+- status: Connection status: 1 connected, 2 disconnected, 3 unknown (same values
+  as those exposed by the "status" property of a connector)
+
 To finish the configuration, link the different pipeline items::
 
   sudo ln -s /config/vkms/my-vkms/crtcs/crtc0 /config/vkms/my-vkms/planes/plane0/possible_crtcs
diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c
index d4d36d2c8f3d..76afb0245388 100644
--- a/drivers/gpu/drm/vkms/vkms_configfs.c
+++ b/drivers/gpu/drm/vkms/vkms_configfs.c
@@ -7,6 +7,7 @@
 #include "vkms_drv.h"
 #include "vkms_config.h"
 #include "vkms_configfs.h"
+#include "vkms_connector.h"
 
 /* To avoid registering configfs more than once or unregistering on error */
 static bool is_configfs_registered;
@@ -496,6 +497,50 @@ static const struct config_item_type encoder_group_type = {
 	.ct_owner	= THIS_MODULE,
 };
 
+static ssize_t connector_status_show(struct config_item *item, char *page)
+{
+	struct vkms_configfs_connector *connector;
+
+	connector = connector_item_to_vkms_configfs_connector(item);
+
+	guard(mutex)(&connector->dev->lock);
+	return sprintf(page, "%u",
+		       vkms_config_connector_get_status(connector->config));
+}
+
+static ssize_t connector_status_store(struct config_item *item,
+				      const char *page, size_t count)
+{
+	struct vkms_configfs_connector *connector;
+	enum drm_connector_status status;
+
+	connector = connector_item_to_vkms_configfs_connector(item);
+
+	if (kstrtouint(page, 10, &status))
+		return -EINVAL;
+
+	if (status != connector_status_connected &&
+	    status != connector_status_disconnected &&
+	    status != connector_status_unknown)
+		return -EINVAL;
+
+	guard(mutex)(&connector->dev->lock);
+
+	vkms_config_connector_set_status(connector->config, status);
+
+	if (connector->dev->enabled)
+		vkms_trigger_connector_hotplug(connector->dev->config->dev);
+
+	return (ssize_t)count;
+}
+
+CONFIGFS_ATTR(connector_, status);
+
+static struct configfs_attribute *connector_item_attrs[] = {
+	&connector_attr_status,
+	NULL,
+};
+
 static void connector_release(struct config_item *item)
 {
 	struct vkms_configfs_connector *connector;
@@ -514,6 +559,7 @@ static struct configfs_item_operations connector_item_operations = {
 };
 
 static const struct config_item_type connector_item_type = {
+	.ct_attrs	= connector_item_attrs,
 	.ct_item_ops	= &connector_item_operations,
 	.ct_owner	= THIS_MODULE,
 };
diff --git a/drivers/gpu/drm/vkms/vkms_connector.c b/drivers/gpu/drm/vkms/vkms_connector.c
index b03a00b5803a..ed99270c590f 100644
--- a/drivers/gpu/drm/vkms/vkms_connector.c
+++ b/drivers/gpu/drm/vkms/vkms_connector.c
@@ -76,3 +76,10 @@ struct vkms_connector *vkms_connector_init(struct vkms_device *vkmsdev,
 
 	return connector;
 }
+
+void vkms_trigger_connector_hotplug(struct vkms_device *vkmsdev)
+{
+	struct drm_device *dev = &vkmsdev->drm;
+
+	drm_kms_helper_hotplug_event(dev);
+}
diff --git a/drivers/gpu/drm/vkms/vkms_connector.h b/drivers/gpu/drm/vkms/vkms_connector.h
index 5ab8a6d65182..7865f54a313c 100644
--- a/drivers/gpu/drm/vkms/vkms_connector.h
+++ b/drivers/gpu/drm/vkms/vkms_connector.h
@@ -33,4 +33,10 @@ struct vkms_connector {
 struct vkms_connector *vkms_connector_init(struct vkms_device *vkmsdev,
 					   struct vkms_config_connector *connector_cfg);
 
+/**
+ * struct vkms_device *vkmsdev() - Update the device's connectors status
+ * @vkmsdev: VKMS device to update
+ */
+void vkms_trigger_connector_hotplug(struct vkms_device *vkmsdev);
+
 #endif /* _VKMS_CONNECTOR_H_ */
-- 
2.48.1