drm/virtio: add edid support

linux guest driver implementation of the VIRTIO_GPU_F_EDID feature.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20181030063206.19528-3-kraxel@redhat.com

1 files changed, 67 insertions, 0 deletions

diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 93f2c3a51ee8..2c6764f08f18 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -584,6 +584,45 @@ static void virtio_gpu_cmd_capset_cb(struct virtio_gpu_device *vgdev,
 	wake_up(&vgdev->resp_wq);
 }
 
+static int virtio_get_edid_block(void *data, u8 *buf,
+				 unsigned int block, size_t len)
+{
+	struct virtio_gpu_resp_edid *resp = data;
+	size_t start = block * EDID_LENGTH;
+
+	if (start + len > le32_to_cpu(resp->size))
+		return -1;
+	memcpy(buf, resp->edid + start, len);
+	return 0;
+}
+
+static void virtio_gpu_cmd_get_edid_cb(struct virtio_gpu_device *vgdev,
+				       struct virtio_gpu_vbuffer *vbuf)
+{
+	struct virtio_gpu_cmd_get_edid *cmd =
+		(struct virtio_gpu_cmd_get_edid *)vbuf->buf;
+	struct virtio_gpu_resp_edid *resp =
+		(struct virtio_gpu_resp_edid *)vbuf->resp_buf;
+	uint32_t scanout = le32_to_cpu(cmd->scanout);
+	struct virtio_gpu_output *output;
+	struct edid *new_edid, *old_edid;
+
+	if (scanout >= vgdev->num_scanouts)
+		return;
+	output = vgdev->outputs + scanout;
+
+	new_edid = drm_do_get_edid(&output->conn, virtio_get_edid_block, resp);
+
+	spin_lock(&vgdev->display_info_lock);
+	old_edid = output->edid;
+	output->edid = new_edid;
+	drm_connector_update_edid_property(&output->conn, output->edid);
+	spin_unlock(&vgdev->display_info_lock);
+
+	kfree(old_edid);
+	wake_up(&vgdev->resp_wq);
+}
+
 int virtio_gpu_cmd_get_display_info(struct virtio_gpu_device *vgdev)
 {
 	struct virtio_gpu_ctrl_hdr *cmd_p;
@@ -686,6 +725,34 @@ int virtio_gpu_cmd_get_capset(struct virtio_gpu_device *vgdev,
 	return 0;
 }
 
+int virtio_gpu_cmd_get_edids(struct virtio_gpu_device *vgdev)
+{
+	struct virtio_gpu_cmd_get_edid *cmd_p;
+	struct virtio_gpu_vbuffer *vbuf;
+	void *resp_buf;
+	int scanout;
+
+	if (WARN_ON(!vgdev->has_edid))
+		return -EINVAL;
+
+	for (scanout = 0; scanout < vgdev->num_scanouts; scanout++) {
+		resp_buf = kzalloc(sizeof(struct virtio_gpu_resp_edid),
+				   GFP_KERNEL);
+		if (!resp_buf)
+			return -ENOMEM;
+
+		cmd_p = virtio_gpu_alloc_cmd_resp
+			(vgdev, &virtio_gpu_cmd_get_edid_cb, &vbuf,
+			 sizeof(*cmd_p), sizeof(struct virtio_gpu_resp_edid),
+			 resp_buf);
+		cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_GET_EDID);
+		cmd_p->scanout = cpu_to_le32(scanout);
+		virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
+	}
+
+	return 0;
+}
+
 void virtio_gpu_cmd_context_create(struct virtio_gpu_device *vgdev, uint32_t id,
 				   uint32_t nlen, const char *name)
 {