[PATCH RFC v3 08/14] drm/vkms: Introduce configfs for connector type

[Louis Chauvet]

To allows the userspace to test many hardware configuration, introduce a
new interface to change a connector type.

The type of a connector can be changed by editing the file type and by
writing the connector type number.

The current interface is:
/config/vkms
	DEVICE_1
        ┣━ enable
        ┣━ planes
        ┃  ┗━ [...]
        ┣━ connectors
        ┃  ┗━ CONNECTOR_1
        ┃     ┣━ possible_encoders
        ┃     ┗━ type
        ┗━ encoders
           ┗━ [...]

Signed-off-by: Louis Chauvet <louis.chauvet at bootlin.com>
---
 drivers/gpu/drm/vkms/vkms_configfs.c | 71 ++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c
index 8bb3223c810dddb7d713ad4b01cece825f9939f6..5f416260f209fc98939f8addd175e5c3b8e35353 100644
--- a/drivers/gpu/drm/vkms/vkms_configfs.c
+++ b/drivers/gpu/drm/vkms/vkms_configfs.c
@@ -633,12 +633,83 @@ static void connector_release(struct config_item *item)
 	kfree(vkms_configfs_connector);
 }
 
+static ssize_t connector_type_show(struct config_item *item, char *page)
+{
+	struct vkms_config_connector *connector;
+	int connector_type;
+	struct vkms_configfs_device *vkms_configfs = connector_child_item_to_vkms_configfs_device(item);
+
+	mutex_lock(&vkms_configfs->lock);
+	connector = connector_item_to_vkms_configfs_connector(item)->vkms_config_connector;
+	connector_type = connector->type;
+	mutex_unlock(&vkms_configfs->lock);
+
+	return sprintf(page, "%u", connector_type);
+}
+
+static ssize_t connector_type_store(struct config_item *item,
+				    const char *page, size_t count)
+{
+	struct vkms_config_connector *connector;
+	int val = DRM_MODE_CONNECTOR_VIRTUAL;
+	struct vkms_configfs_device *vkms_configfs = connector_child_item_to_vkms_configfs_device(item);
+	int ret;
+
+	ret = kstrtouint(page, 10, &val);
+	if (ret)
+		return ret;
+
+	switch (val) {
+	case DRM_MODE_CONNECTOR_Unknown:
+	case DRM_MODE_CONNECTOR_VGA:
+	case DRM_MODE_CONNECTOR_DVII:
+	case DRM_MODE_CONNECTOR_DVID:
+	case DRM_MODE_CONNECTOR_DVIA:
+	case DRM_MODE_CONNECTOR_Composite:
+	case DRM_MODE_CONNECTOR_SVIDEO:
+	case DRM_MODE_CONNECTOR_LVDS:
+	case DRM_MODE_CONNECTOR_Component:
+	case DRM_MODE_CONNECTOR_9PinDIN:
+	case DRM_MODE_CONNECTOR_DisplayPort:
+	case DRM_MODE_CONNECTOR_HDMIA:
+	case DRM_MODE_CONNECTOR_HDMIB:
+	case DRM_MODE_CONNECTOR_TV:
+	case DRM_MODE_CONNECTOR_eDP:
+	case DRM_MODE_CONNECTOR_VIRTUAL:
+	case DRM_MODE_CONNECTOR_DSI:
+	case DRM_MODE_CONNECTOR_DPI:
+	case DRM_MODE_CONNECTOR_SPI:
+	case DRM_MODE_CONNECTOR_USB:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	scoped_guard(mutex, &vkms_configfs->lock) {
+		if (vkms_configfs->enabled)
+			return -EINVAL;
+
+		connector = connector_item_to_vkms_configfs_connector(item)->vkms_config_connector;
+		connector->type = val;
+	}
+
+	return count;
+}
+
+CONFIGFS_ATTR(connector_, type);
+
+static struct configfs_attribute *connector_attrs[] = {
+	&connector_attr_type,
+	NULL,
+};
+
 static struct configfs_item_operations connector_item_operations = {
 	.release = connector_release,
 };
 
 static const struct config_item_type connector_item_type = {
 	.ct_item_ops = &connector_item_operations,
+	.ct_attrs = connector_attrs,
 	.ct_owner = THIS_MODULE,
 };
 

-- 
2.47.1