[media] v4l: Create v4l2 subdev file handle structure

Used for storing subdev information per file handle and hold V4L2 file
handle.
Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Signed-off-by: Antti Koskipaa <akoskipa@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/Kconfig

@@ -53,6 +53,15 @@ config VIDEO_V4L2_COMMON
 	depends on (I2C || I2C=n) && VIDEO_DEV
 	default (I2C || I2C=n) && VIDEO_DEV
 
+config VIDEO_V4L2_SUBDEV_API
+	bool "V4L2 sub-device userspace API (EXPERIMENTAL)"
+	depends on VIDEO_DEV && MEDIA_CONTROLLER && EXPERIMENTAL
+	---help---
+	  Enables the V4L2 sub-device pad-level userspace API used to configure
+	  video format, size and frame rate between hardware blocks.
+
+	  This API is mostly used by camera interfaces in embedded platforms.
+
 #
 # DVB Core
 #

drivers/media/video/v4l2-subdev.c

@@ -31,36 +31,66 @@
 #include <media/v4l2-fh.h>
 #include <media/v4l2-event.h>
 
+static int subdev_fh_init(struct v4l2_subdev_fh *fh, struct v4l2_subdev *sd)
+{
+#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
+	/* Allocate try format and crop in the same memory block */
+	fh->try_fmt = kzalloc((sizeof(*fh->try_fmt) + sizeof(*fh->try_crop))
+			      * sd->entity.num_pads, GFP_KERNEL);
+	if (fh->try_fmt == NULL)
+		return -ENOMEM;
+
+	fh->try_crop = (struct v4l2_rect *)
+		(fh->try_fmt + sd->entity.num_pads);
+#endif
+	return 0;
+}
+
+static void subdev_fh_free(struct v4l2_subdev_fh *fh)
+{
+#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
+	kfree(fh->try_fmt);
+	fh->try_fmt = NULL;
+	fh->try_crop = NULL;
+#endif
+}
+
 static int subdev_open(struct file *file)
 {
 	struct video_device *vdev = video_devdata(file);
 	struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
+	struct v4l2_subdev_fh *subdev_fh;
 #if defined(CONFIG_MEDIA_CONTROLLER)
 	struct media_entity *entity;
 #endif
-	struct v4l2_fh *vfh = NULL;
 	int ret;
 
-	if (sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS) {
-		vfh = kzalloc(sizeof(*vfh), GFP_KERNEL);
-		if (vfh == NULL)
+	subdev_fh = kzalloc(sizeof(*subdev_fh), GFP_KERNEL);
+	if (subdev_fh == NULL)
 		return -ENOMEM;
 
-		ret = v4l2_fh_init(vfh, vdev);
+	ret = subdev_fh_init(subdev_fh, sd);
+	if (ret) {
+		kfree(subdev_fh);
+		return ret;
+	}
+
+	ret = v4l2_fh_init(&subdev_fh->vfh, vdev);
 	if (ret)
 		goto err;
 
-		ret = v4l2_event_init(vfh);
+	if (sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS) {
+		ret = v4l2_event_init(&subdev_fh->vfh);
 		if (ret)
 			goto err;
 
-		ret = v4l2_event_alloc(vfh, sd->nevents);
+		ret = v4l2_event_alloc(&subdev_fh->vfh, sd->nevents);
 		if (ret)
 			goto err;
-
-		v4l2_fh_add(vfh);
-		file->private_data = vfh;
 	}
+
+	v4l2_fh_add(&subdev_fh->vfh);
+	file->private_data = &subdev_fh->vfh;
 #if defined(CONFIG_MEDIA_CONTROLLER)
 	if (sd->v4l2_dev->mdev) {
 		entity = media_entity_get(&sd->entity);
@@ -70,14 +100,14 @@ static int subdev_open(struct file *file)
 		}
 	}
 #endif
+
 	return 0;
 
 err:
-	if (vfh != NULL) {
-		v4l2_fh_del(vfh);
-		v4l2_fh_exit(vfh);
-		kfree(vfh);
-	}
+	v4l2_fh_del(&subdev_fh->vfh);
+	v4l2_fh_exit(&subdev_fh->vfh);
+	subdev_fh_free(subdev_fh);
+	kfree(subdev_fh);
 
 	return ret;
 }
@@ -89,16 +119,17 @@ static int subdev_close(struct file *file)
 	struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
 #endif
 	struct v4l2_fh *vfh = file->private_data;
+	struct v4l2_subdev_fh *subdev_fh = to_v4l2_subdev_fh(vfh);
 
 #if defined(CONFIG_MEDIA_CONTROLLER)
 	if (sd->v4l2_dev->mdev)
 		media_entity_put(&sd->entity);
 #endif
-	if (vfh != NULL) {
 	v4l2_fh_del(vfh);
 	v4l2_fh_exit(vfh);
-		kfree(vfh);
-	}
+	subdev_fh_free(subdev_fh);
+	kfree(subdev_fh);
+	file->private_data = NULL;
 
 	return 0;
 }
@@ -107,7 +138,7 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
 {
 	struct video_device *vdev = video_devdata(file);
 	struct v4l2_subdev *sd = vdev_to_v4l2_subdev(vdev);
-	struct v4l2_fh *fh = file->private_data;
+	struct v4l2_fh *vfh = file->private_data;
 
 	switch (cmd) {
 	case VIDIOC_QUERYCTRL:
@@ -135,13 +166,13 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg)
 		if (!(sd->flags & V4L2_SUBDEV_FL_HAS_EVENTS))
 			return -ENOIOCTLCMD;
 
-		return v4l2_event_dequeue(fh, arg, file->f_flags & O_NONBLOCK);
+		return v4l2_event_dequeue(vfh, arg, file->f_flags & O_NONBLOCK);
 
 	case VIDIOC_SUBSCRIBE_EVENT:
-		return v4l2_subdev_call(sd, core, subscribe_event, fh, arg);
+		return v4l2_subdev_call(sd, core, subscribe_event, vfh, arg);
 
 	case VIDIOC_UNSUBSCRIBE_EVENT:
-		return v4l2_subdev_call(sd, core, unsubscribe_event, fh, arg);
+		return v4l2_subdev_call(sd, core, unsubscribe_event, vfh, arg);
 
 	default:
 		return -ENOIOCTLCMD;

include/media/v4l2-subdev.h

@@ -24,6 +24,7 @@
 #include <media/media-entity.h>
 #include <media/v4l2-common.h>
 #include <media/v4l2-dev.h>
+#include <media/v4l2-fh.h>
 #include <media/v4l2-mediabus.h>
 
 /* generic v4l2_device notify callback notification values */
@@ -481,6 +482,34 @@ struct v4l2_subdev {
 #define vdev_to_v4l2_subdev(vdev) \
 	container_of(vdev, struct v4l2_subdev, devnode)
 
+/*
+ * Used for storing subdev information per file handle
+ */
+struct v4l2_subdev_fh {
+	struct v4l2_fh vfh;
+#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
+	struct v4l2_mbus_framefmt *try_fmt;
+	struct v4l2_rect *try_crop;
+#endif
+};
+
+#define to_v4l2_subdev_fh(fh)	\
+	container_of(fh, struct v4l2_subdev_fh, vfh)
+
+#if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)
+static inline struct v4l2_mbus_framefmt *
+v4l2_subdev_get_try_format(struct v4l2_subdev_fh *fh, unsigned int pad)
+{
+	return &fh->try_fmt[pad];
+}
+
+static inline struct v4l2_rect *
+v4l2_subdev_get_try_crop(struct v4l2_subdev_fh *fh, unsigned int pad)
+{
+	return &fh->try_crop[pad];
+}
+#endif
+
 extern const struct v4l2_file_operations v4l2_subdev_fops;
 
 static inline void v4l2_set_subdevdata(struct v4l2_subdev *sd, void *p)