[PATCH v2, 2/2] media: v4l: Add Ro request api for capture queue

Yunfei Dong yunfei.dong at mediatek.com
Sun Jun 21 21:52:27 EDT 2020


Add Read-only(Ro) request for capture queue. Ro request mean that
user driver can get ext ctrls, buf set ext ctrls is not allowed.

Add param ro_requests in struct v4l2_ctrl_handler to present current
ctrl is read only. Add param ro_ctrl_handler in struct v4l2_fh used
for ro request.

When set/get ext ctrls, will check whether current CID ctrls is ro ctrls
or not using function v4l2_check_ro_ext_ctrls().

Signed-off-by: Yunfei Dong <yunfei.dong at mediatek.com>
---
 .../media/common/videobuf2/videobuf2-v4l2.c   |   7 ++
 drivers/media/mc/mc-request.c                 |  10 +-
 drivers/media/v4l2-core/v4l2-ctrls.c          | 107 +++++++++++++++---
 drivers/media/v4l2-core/v4l2-ioctl.c          |  22 ++++
 drivers/media/v4l2-core/v4l2-mem2mem.c        |  19 ++--
 include/media/v4l2-ctrls.h                    |  22 +++-
 include/media/v4l2-fh.h                       |   2 +
 include/media/videobuf2-core.h                |   2 +
 include/uapi/linux/videodev2.h                |   1 +
 9 files changed, 154 insertions(+), 38 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index eb5d5db96552..91a6f3a0c208 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -402,6 +402,11 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct media_device *md
 			return -EBUSY;
 		}
 		return 0;
+	} else if (!V4L2_TYPE_IS_OUTPUT(q->type)) {
+		if (!q->supports_ro_requests || q->supports_requests) {
+			dprintk(1, "%s: cap queue use ro requests\n", opname);
+			return -EBADR;
+		}
 	} else if (!q->supports_requests) {
 		dprintk(1, "%s: queue does not support requests\n", opname);
 		return -EBADR;
@@ -665,6 +670,8 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
 #ifdef CONFIG_MEDIA_CONTROLLER_REQUEST_API
 	if (q->supports_requests)
 		*caps |= V4L2_BUF_CAP_SUPPORTS_REQUESTS;
+	if (q->supports_ro_requests)
+		*caps |= V4L2_BUF_CAP_SUPPORTS_RO_REQUESTS;
 #endif
 }
 
diff --git a/drivers/media/mc/mc-request.c b/drivers/media/mc/mc-request.c
index e3fca436c75b..e50ae259c1ff 100644
--- a/drivers/media/mc/mc-request.c
+++ b/drivers/media/mc/mc-request.c
@@ -404,16 +404,12 @@ int media_request_object_bind(struct media_request *req,
 			      struct media_request_object *obj)
 {
 	unsigned long flags;
-	int ret = -EBUSY;
 
 	if (WARN_ON(!ops->release))
 		return -EBADR;
 
 	spin_lock_irqsave(&req->lock, flags);
 
-	if (WARN_ON(req->state != MEDIA_REQUEST_STATE_UPDATING))
-		goto unlock;
-
 	obj->req = req;
 	obj->ops = ops;
 	obj->priv = priv;
@@ -423,11 +419,9 @@ int media_request_object_bind(struct media_request *req,
 	else
 		list_add(&obj->list, &req->objects);
 	req->num_incomplete_objects++;
-	ret = 0;
-
-unlock:
 	spin_unlock_irqrestore(&req->lock, flags);
-	return ret;
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(media_request_object_bind);
 
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 3f3fbcd60cc6..effc26f733de 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -3386,22 +3386,6 @@ static const struct media_request_object_ops req_ops = {
 	.release = v4l2_ctrl_request_release,
 };
 
-struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
-					struct v4l2_ctrl_handler *parent)
-{
-	struct media_request_object *obj;
-
-	if (WARN_ON(req->state != MEDIA_REQUEST_STATE_VALIDATING &&
-		    req->state != MEDIA_REQUEST_STATE_QUEUED))
-		return NULL;
-
-	obj = media_request_object_find(req, &req_ops, parent);
-	if (obj)
-		return container_of(obj, struct v4l2_ctrl_handler, req_obj);
-	return NULL;
-}
-EXPORT_SYMBOL_GPL(v4l2_ctrl_request_hdl_find);
-
 struct v4l2_ctrl *
 v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id)
 {
@@ -3420,6 +3404,10 @@ static int v4l2_ctrl_request_bind(struct media_request *req,
 	ret = v4l2_ctrl_request_clone(hdl, from);
 
 	if (!ret) {
+		if (!hdl->ro_requests &&
+			WARN_ON(req->state != MEDIA_REQUEST_STATE_UPDATING))
+			return -EBUSY;
+
 		ret = media_request_object_bind(req, &req_ops,
 						from, false, &hdl->req_obj);
 		if (!ret)
@@ -3593,6 +3581,62 @@ static int class_check(struct v4l2_ctrl_handler *hdl, u32 which)
 	return find_ref_lock(hdl, which | 1) ? 0 : -EINVAL;
 }
 
+int v4l2_check_ro_ext_ctrls(struct v4l2_ctrl_handler *hdl,
+		   struct video_device *vdev, struct media_device *mdev,
+		   struct v4l2_ext_controls *cs)
+{
+	struct v4l2_ctrl_ref *ref;
+	u32 i;
+
+	if (cs->which == V4L2_CTRL_WHICH_REQUEST_VAL) {
+		if (!mdev || cs->request_fd < 0)
+			return -EINVAL;
+	}
+
+	cs->error_idx = cs->count;
+	cs->which = V4L2_CTRL_ID2WHICH(cs->which);
+
+	if (hdl == NULL)
+		return -EINVAL;
+
+	if (cs->count == 0)
+		return class_check(hdl, cs->which);
+
+	for (i = 0; i < cs->count; i++) {
+		struct v4l2_ext_control *c = &cs->controls[i];
+		u32 id = c->id & V4L2_CTRL_ID_MASK;
+
+		cs->error_idx = i;
+
+		if (cs->which &&
+			cs->which != V4L2_CTRL_WHICH_DEF_VAL &&
+			cs->which != V4L2_CTRL_WHICH_REQUEST_VAL &&
+			V4L2_CTRL_ID2WHICH(id) != cs->which) {
+			dprintk(vdev,
+					"invalid which 0x%x or control id 0x%x\n",
+					cs->which, id);
+			return -EINVAL;
+		}
+
+		/* Old-style private controls are not allowed for
+		 *extended controls
+		 */
+		if (id >= V4L2_CID_PRIVATE_BASE) {
+			dprintk(vdev,
+					"old-style private controls not allowed\n");
+			return -EINVAL;
+		}
+
+		ref = find_ref_lock(hdl, id);
+		if (ref == NULL) {
+			dprintk(vdev, "cannot find control id 0x%x\n", id);
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL(v4l2_check_ro_ext_ctrls);
+
 /* Get extended controls. Allocates the helpers array if needed. */
 static int v4l2_g_ext_ctrls_common(struct v4l2_ctrl_handler *hdl,
 				   struct v4l2_ext_controls *cs,
@@ -3694,7 +3738,7 @@ v4l2_ctrls_find_req_obj(struct v4l2_ctrl_handler *hdl,
 	obj = media_request_object_find(req, &req_ops, hdl);
 	if (obj)
 		return obj;
-	if (!set)
+	if (!set && !hdl->ro_requests)
 		return ERR_PTR(-ENOENT);
 
 	new_hdl = kzalloc(sizeof(*new_hdl), GFP_KERNEL);
@@ -3702,6 +3746,7 @@ v4l2_ctrls_find_req_obj(struct v4l2_ctrl_handler *hdl,
 		return ERR_PTR(-ENOMEM);
 
 	obj = &new_hdl->req_obj;
+	new_hdl->ro_requests = hdl->ro_requests;
 	ret = v4l2_ctrl_handler_init(new_hdl, (hdl->nr_of_buckets - 1) * 8);
 	if (!ret)
 		ret = v4l2_ctrl_request_bind(req, new_hdl, hdl);
@@ -3763,6 +3808,28 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct video_device *vdev,
 }
 EXPORT_SYMBOL(v4l2_g_ext_ctrls);
 
+struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
+					struct v4l2_ctrl_handler *parent)
+{
+	struct media_request_object *obj;
+
+	if (WARN_ON(req->state != MEDIA_REQUEST_STATE_VALIDATING &&
+		    req->state != MEDIA_REQUEST_STATE_QUEUED))
+		return NULL;
+
+	obj = media_request_object_find(req, &req_ops, parent);
+	if (!obj) {
+		if (parent->ro_requests) {
+			obj = v4l2_ctrls_find_req_obj(parent, req, false);
+			if (IS_ERR(obj))
+				return NULL;
+		} else
+			return NULL;
+	}
+	return container_of(obj, struct v4l2_ctrl_handler, req_obj);
+}
+EXPORT_SYMBOL_GPL(v4l2_ctrl_request_hdl_find);
+
 /* Helper function to get a single control */
 static int get_ctrl(struct v4l2_ctrl *ctrl, struct v4l2_ext_control *c)
 {
@@ -4094,6 +4161,12 @@ static int try_set_ext_ctrls(struct v4l2_fh *fh,
 	int ret;
 
 	if (cs->which == V4L2_CTRL_WHICH_REQUEST_VAL) {
+		if (hdl->ro_requests) {
+			dprintk(vdev, "%s: ro requests can`t set ext ctrls\n",
+				video_device_node_name(vdev));
+			return -EINVAL;
+		}
+
 		if (!mdev) {
 			dprintk(vdev, "%s: missing media device\n",
 				video_device_node_name(vdev));
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 2322f08a98be..b9e1058a5067 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -2270,6 +2270,13 @@ static int v4l_g_ext_ctrls(const struct v4l2_ioctl_ops *ops,
 		test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) ? fh : NULL;
 
 	p->error_idx = p->count;
+	if (vfh && vfh->ro_ctrl_handler) {
+		if (!v4l2_check_ro_ext_ctrls(vfh->ro_ctrl_handler, vfd,
+						vfd->v4l2_dev->mdev, p)) {
+			return v4l2_g_ext_ctrls(vfh->ro_ctrl_handler, vfd,
+						vfd->v4l2_dev->mdev, p);
+		}
+	}
 	if (vfh && vfh->ctrl_handler)
 		return v4l2_g_ext_ctrls(vfh->ctrl_handler,
 					vfd, vfd->v4l2_dev->mdev, p);
@@ -2291,6 +2298,14 @@ static int v4l_s_ext_ctrls(const struct v4l2_ioctl_ops *ops,
 		test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) ? fh : NULL;
 
 	p->error_idx = p->count;
+	if (vfh && vfh->ro_ctrl_handler) {
+		if (!v4l2_check_ro_ext_ctrls(vfh->ro_ctrl_handler, vfd,
+						vfd->v4l2_dev->mdev, p)) {
+			return v4l2_s_ext_ctrls(vfh, vfh->ro_ctrl_handler, vfd,
+						vfd->v4l2_dev->mdev, p);
+		}
+	}
+
 	if (vfh && vfh->ctrl_handler)
 		return v4l2_s_ext_ctrls(vfh, vfh->ctrl_handler,
 					vfd, vfd->v4l2_dev->mdev, p);
@@ -2312,6 +2327,13 @@ static int v4l_try_ext_ctrls(const struct v4l2_ioctl_ops *ops,
 		test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags) ? fh : NULL;
 
 	p->error_idx = p->count;
+	if (vfh && vfh->ro_ctrl_handler) {
+		if (!v4l2_check_ro_ext_ctrls(vfh->ro_ctrl_handler, vfd,
+						vfd->v4l2_dev->mdev, p)) {
+			return v4l2_try_ext_ctrls(vfh->ro_ctrl_handler, vfd,
+						vfd->v4l2_dev->mdev, p);
+		}
+	}
 	if (vfh && vfh->ctrl_handler)
 		return v4l2_try_ext_ctrls(vfh->ctrl_handler,
 					  vfd, vfd->v4l2_dev->mdev, p);
diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index 62ac9424c92a..166e94ee18a7 100644
--- a/drivers/media/v4l2-core/v4l2-mem2mem.c
+++ b/drivers/media/v4l2-core/v4l2-mem2mem.c
@@ -712,13 +712,6 @@ int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 	int ret;
 
 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
-	if (!V4L2_TYPE_IS_OUTPUT(vq->type) &&
-	    (buf->flags & V4L2_BUF_FLAG_REQUEST_FD)) {
-		dprintk("%s: requests cannot be used with capture buffers\n",
-			__func__);
-		return -EPERM;
-	}
-
 	ret = vb2_qbuf(vq, vdev->v4l2_dev->mdev, buf);
 	if (ret)
 		return ret;
@@ -1252,10 +1245,14 @@ void v4l2_m2m_request_queue(struct media_request *req)
 		if (vb2_request_object_is_buffer(obj)) {
 			/* Sanity checks */
 			vb = container_of(obj, struct vb2_buffer, req_obj);
-			WARN_ON(!V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type));
-			m2m_ctx_obj = container_of(vb->vb2_queue,
-						   struct v4l2_m2m_ctx,
-						   out_q_ctx.q);
+			if (V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type))
+				m2m_ctx_obj = container_of(vb->vb2_queue,
+							struct v4l2_m2m_ctx,
+							out_q_ctx.q);
+			else
+				m2m_ctx_obj = container_of(vb->vb2_queue,
+							struct v4l2_m2m_ctx,
+							cap_q_ctx.q);
 			WARN_ON(m2m_ctx && m2m_ctx_obj != m2m_ctx);
 			m2m_ctx = m2m_ctx_obj;
 		}
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index f40e2cbb21d3..5b10c2e8a402 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -345,6 +345,7 @@ struct v4l2_ctrl_ref {
  * @nr_of_buckets: Total number of buckets in the array.
  * @error:	The error code of the first failed control addition.
  * @request_is_queued: True if the request was queued.
+ * @ro_requests: True if the queue support ro request.
  * @requests:	List to keep track of open control handler request objects.
  *		For the parent control handler (@req_obj.req == NULL) this
  *		is the list header. When the parent control handler is
@@ -368,6 +369,7 @@ struct v4l2_ctrl_handler {
 	u16 nr_of_buckets;
 	int error;
 	bool request_is_queued;
+	bool ro_requests;
 	struct list_head requests;
 	struct list_head requests_queued;
 	struct media_request_object req_obj;
@@ -1261,8 +1263,10 @@ void v4l2_ctrl_request_complete(struct media_request *req,
  * @parent: The parent control handler ('priv' in media_request_object_find())
  *
  * This function finds the control handler in the request. It may return
- * NULL if not found. When done, you must call v4l2_ctrl_request_put_hdl()
- * with the returned handler pointer.
+ * NULL if not found. But for Ro Request, the request object maybe
+ * NULL, need to call v4l2_ctrls_find_req_obj() to check whether the
+ * request has request object. When done, you must call
+ * v4l2_ctrl_request_put_hdl() with the returned handler pointer.
  *
  * If the request is not in state VALIDATING or QUEUED, then this function
  * will always return NULL.
@@ -1454,4 +1458,18 @@ int v4l2_ctrl_subdev_log_status(struct v4l2_subdev *sd);
 int v4l2_ctrl_new_fwnode_properties(struct v4l2_ctrl_handler *hdl,
 				    const struct v4l2_ctrl_ops *ctrl_ops,
 				    const struct v4l2_fwnode_device_properties *p);
+/**
+ * v4l2_check_ro_ext_ctrls - Check whether the ext controls are ro request
+ *
+ * @hdl: pointer to &struct v4l2_ctrl_handler
+ * @vdev: pointer to &struct video_device
+ * @mdev: pointer to &struct media_device
+ * @cs: pointer to &struct v4l2_ext_controls
+ *
+ * If hdl == NULL then they will all return -EINVAL.
+ */
+int v4l2_check_ro_ext_ctrls(struct v4l2_ctrl_handler *hdl,
+			    struct video_device *vdev,
+			    struct media_device *mdev,
+			    struct v4l2_ext_controls *cs);
 #endif
diff --git a/include/media/v4l2-fh.h b/include/media/v4l2-fh.h
index b5b3e00c8e6a..479abef6c910 100644
--- a/include/media/v4l2-fh.h
+++ b/include/media/v4l2-fh.h
@@ -27,6 +27,7 @@ struct v4l2_ctrl_handler;
  * @list: list of file handlers
  * @vdev: pointer to &struct video_device
  * @ctrl_handler: pointer to &struct v4l2_ctrl_handler
+ * @ro_ctrl_handler: pointer to &struct v4l2_ctrl_handler used for ro ctrls
  * @prio: priority of the file handler, as defined by &enum v4l2_priority
  *
  * @wait: event' s wait queue
@@ -43,6 +44,7 @@ struct v4l2_fh {
 	struct list_head	list;
 	struct video_device	*vdev;
 	struct v4l2_ctrl_handler *ctrl_handler;
+	struct v4l2_ctrl_handler *ro_ctrl_handler;
 	enum v4l2_priority	prio;
 
 	/* Events */
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index f11b96514cf7..dce5c6781be9 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -483,6 +483,7 @@ struct vb2_buf_ops {
  *              has not been called. This is a vb1 idiom that has been adopted
  *              also by vb2.
  * @supports_requests: this queue supports the Request API.
+ * @supports_ro_requests: this queue supports the RO Request API.
  * @requires_requests: this queue requires the Request API. If this is set to 1,
  *		then supports_requests must be set to 1 as well.
  * @uses_qbuf:	qbuf was used directly for this queue. Set to 1 the first
@@ -564,6 +565,7 @@ struct vb2_queue {
 	unsigned			allow_zero_bytesused:1;
 	unsigned		   quirk_poll_must_check_waiting_for_buffers:1;
 	unsigned			supports_requests:1;
+	unsigned			supports_ro_requests:1;
 	unsigned			requires_requests:1;
 	unsigned			uses_qbuf:1;
 	unsigned			uses_requests:1;
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index c3a1cf1c507f..25793c737eab 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -954,6 +954,7 @@ struct v4l2_requestbuffers {
 #define V4L2_BUF_CAP_SUPPORTS_REQUESTS			(1 << 3)
 #define V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS		(1 << 4)
 #define V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF	(1 << 5)
+#define V4L2_BUF_CAP_SUPPORTS_RO_REQUESTS		(1 << 6)
 
 /**
  * struct v4l2_plane - plane info for multi-planar buffers
-- 
2.18.0


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