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| author | Hans Verkuil <hverkuil@xs4all.nl> | 2010-12-29 10:05:02 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-03-22 16:37:54 -0300 |
| commit | 022654930891c7ddfdb1ea34d6c4af9d1096bf91 (patch) | |
| tree | 396edb9d7c4dcde4e862e89b2ed4b770ad830462 /drivers/media/video/v4l2-dev.c | |
| parent | 8c1476ffc0b820f6ca8cc0b3f50c8a0f57e8d82d (diff) | |
| download | blackbird-obmc-linux-022654930891c7ddfdb1ea34d6c4af9d1096bf91.tar.gz blackbird-obmc-linux-022654930891c7ddfdb1ea34d6c4af9d1096bf91.zip | |
[media] v4l2_prio: move from v4l2-common to v4l2-dev
We are going to move priority handling into the v4l2 core. As a consequence
the v4l2_prio helper functions need to be moved into the core videodev
module as well to prevent circular dependencies.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers/media/video/v4l2-dev.c')
| -rw-r--r-- | drivers/media/video/v4l2-dev.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c index e405b8094b94..65d546f35ef4 100644 --- a/drivers/media/video/v4l2-dev.c +++ b/drivers/media/video/v4l2-dev.c @@ -182,6 +182,70 @@ struct video_device *video_devdata(struct file *file) } EXPORT_SYMBOL(video_devdata); + +/* Priority handling */ + +static inline bool prio_is_valid(enum v4l2_priority prio) +{ + return prio == V4L2_PRIORITY_BACKGROUND || + prio == V4L2_PRIORITY_INTERACTIVE || + prio == V4L2_PRIORITY_RECORD; +} + +void v4l2_prio_init(struct v4l2_prio_state *global) +{ + memset(global, 0, sizeof(*global)); +} +EXPORT_SYMBOL(v4l2_prio_init); + +int v4l2_prio_change(struct v4l2_prio_state *global, enum v4l2_priority *local, + enum v4l2_priority new) +{ + if (!prio_is_valid(new)) + return -EINVAL; + if (*local == new) + return 0; + + atomic_inc(&global->prios[new]); + if (prio_is_valid(*local)) + atomic_dec(&global->prios[*local]); + *local = new; + return 0; +} +EXPORT_SYMBOL(v4l2_prio_change); + +void v4l2_prio_open(struct v4l2_prio_state *global, enum v4l2_priority *local) +{ + v4l2_prio_change(global, local, V4L2_PRIORITY_DEFAULT); +} +EXPORT_SYMBOL(v4l2_prio_open); + +void v4l2_prio_close(struct v4l2_prio_state *global, enum v4l2_priority local) +{ + if (prio_is_valid(local)) + atomic_dec(&global->prios[local]); +} +EXPORT_SYMBOL(v4l2_prio_close); + +enum v4l2_priority v4l2_prio_max(struct v4l2_prio_state *global) +{ + if (atomic_read(&global->prios[V4L2_PRIORITY_RECORD]) > 0) + return V4L2_PRIORITY_RECORD; + if (atomic_read(&global->prios[V4L2_PRIORITY_INTERACTIVE]) > 0) + return V4L2_PRIORITY_INTERACTIVE; + if (atomic_read(&global->prios[V4L2_PRIORITY_BACKGROUND]) > 0) + return V4L2_PRIORITY_BACKGROUND; + return V4L2_PRIORITY_UNSET; +} +EXPORT_SYMBOL(v4l2_prio_max); + +int v4l2_prio_check(struct v4l2_prio_state *global, enum v4l2_priority local) +{ + return (local < v4l2_prio_max(global)) ? -EBUSY : 0; +} +EXPORT_SYMBOL(v4l2_prio_check); + + static ssize_t v4l2_read(struct file *filp, char __user *buf, size_t sz, loff_t *off) { |
