[media] v4l: subdev: Add pad config allocator and init

Add a new subdev operation to initialize a subdev pad config array, and
a helper function to allocate and initialize the array. This can be used
by bridge drivers to implement try format based on subdev pad
operations.

Signed-off-by: Laurent Pinchart <laurent.pinchart@linaro.org>
Acked-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c
index 0fa60801a428e60943d98b376bc70c8d13c68632..224ea6028b5505600ed696a23479de298964165a 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -35,9 +35,11 @@
 static int subdev_fh_init(struct v4l2_subdev_fh *fh, struct v4l2_subdev *sd)
 {
 #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
-       fh->pad = kzalloc(sizeof(*fh->pad) * sd->entity.num_pads, GFP_KERNEL);
-       if (fh->pad == NULL)
-               return -ENOMEM;
+       if (sd->entity.num_pads) {
+               fh->pad = v4l2_subdev_alloc_pad_config(sd);
+               if (fh->pad == NULL)
+                       return -ENOMEM;
+       }
 #endif
        return 0;
 }
@@ -45,7 +47,7 @@ static int subdev_fh_init(struct v4l2_subdev_fh *fh, struct v4l2_subdev *sd)
 static void subdev_fh_free(struct v4l2_subdev_fh *fh)
 {
 #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
-       kfree(fh->pad);
+       v4l2_subdev_free_pad_config(fh->pad);
        fh->pad = NULL;
 #endif
 }
@@ -569,6 +571,35 @@ int v4l2_subdev_link_validate(struct media_link *link)
                sink, link, &source_fmt, &sink_fmt);
 }
 EXPORT_SYMBOL_GPL(v4l2_subdev_link_validate);
+
+struct v4l2_subdev_pad_config *
+v4l2_subdev_alloc_pad_config(struct v4l2_subdev *sd)
+{
+       struct v4l2_subdev_pad_config *cfg;
+       int ret;
+
+       if (!sd->entity.num_pads)
+               return NULL;
+
+       cfg = kcalloc(sd->entity.num_pads, sizeof(*cfg), GFP_KERNEL);
+       if (!cfg)
+               return NULL;
+
+       ret = v4l2_subdev_call(sd, pad, init_cfg, cfg);
+       if (ret < 0 && ret != -ENOIOCTLCMD) {
+               kfree(cfg);
+               return NULL;
+       }
+
+       return cfg;
+}
+EXPORT_SYMBOL_GPL(v4l2_subdev_alloc_pad_config);
+
+void v4l2_subdev_free_pad_config(struct v4l2_subdev_pad_config *cfg)
+{
+       kfree(cfg);
+}
+EXPORT_SYMBOL_GPL(v4l2_subdev_free_pad_config);
 #endif /* CONFIG_MEDIA_CONTROLLER */
 
 void v4l2_subdev_init(struct v4l2_subdev *sd, const struct v4l2_subdev_ops *ops)

diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 11e2dfec01988c8818ef531289f88f4f17ef4725..32fc7a4beb5e39af0bd9e3c794250c48b7e31ef8 100644 (file)
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -572,6 +572,7 @@ struct v4l2_subdev_pad_config {
 /**
  * struct v4l2_subdev_pad_ops - v4l2-subdev pad level operations
  *
+ * @init_cfg: initialize the pad config to default values
  * @enum_mbus_code: callback for VIDIOC_SUBDEV_ENUM_MBUS_CODE ioctl handler
  *                 code.
  * @enum_frame_size: callback for VIDIOC_SUBDEV_ENUM_FRAME_SIZE ioctl handler
@@ -607,6 +608,8 @@ struct v4l2_subdev_pad_config {
  *                  may be adjusted by the subdev driver to device capabilities.
  */
 struct v4l2_subdev_pad_ops {
+       int (*init_cfg)(struct v4l2_subdev *sd,
+                       struct v4l2_subdev_pad_config *cfg);
        int (*enum_mbus_code)(struct v4l2_subdev *sd,
                              struct v4l2_subdev_pad_config *cfg,
                              struct v4l2_subdev_mbus_code_enum *code);
@@ -801,7 +804,12 @@ int v4l2_subdev_link_validate_default(struct v4l2_subdev *sd,
                                      struct v4l2_subdev_format *source_fmt,
                                      struct v4l2_subdev_format *sink_fmt);
 int v4l2_subdev_link_validate(struct media_link *link);
+
+struct v4l2_subdev_pad_config *
+v4l2_subdev_alloc_pad_config(struct v4l2_subdev *sd);
+void v4l2_subdev_free_pad_config(struct v4l2_subdev_pad_config *cfg);
 #endif /* CONFIG_MEDIA_CONTROLLER */
+
 void v4l2_subdev_init(struct v4l2_subdev *sd,
                      const struct v4l2_subdev_ops *ops);