Re: [PATCH v3 15/24] media: Add userspace header file for i.MX

[Laurent Pinchart]

Hi Steve,

On Friday 13 Jan 2017 15:13:33 Steve Longerbeam wrote:
> On 01/13/2017 04:05 AM, Philipp Zabel wrote:
> > Am Freitag, den 06.01.2017, 18:11 -0800 schrieb Steve Longerbeam:
> >> This adds a header file for use by userspace programs wanting to interact
> >> with the i.MX media driver. It defines custom v4l2 controls and events
> >> generated by the i.MX v4l2 subdevices.
> >> 
> >> Signed-off-by: Steve Longerbeam <steve_longerbeam@xxxxxxxxxx>
> >> ---
> >> 
> >>   include/uapi/media/Kbuild |  1 +
> >>   include/uapi/media/imx.h  | 30 ++++++++++++++++++++++++++++++
> >>   2 files changed, 31 insertions(+)
> >>   create mode 100644 include/uapi/media/imx.h
> >> 
> >> diff --git a/include/uapi/media/Kbuild b/include/uapi/media/Kbuild
> >> index aafaa5a..fa78958 100644
> >> --- a/include/uapi/media/Kbuild
> >> +++ b/include/uapi/media/Kbuild
> >> @@ -1 +1,2 @@
> >> 
> >>   # UAPI Header export list
> >> 
> >> +header-y += imx.h
> >> diff --git a/include/uapi/media/imx.h b/include/uapi/media/imx.h
> >> new file mode 100644
> >> index 0000000..2421d9c
> >> --- /dev/null
> >> +++ b/include/uapi/media/imx.h
> >> @@ -0,0 +1,30 @@
> >> +/*
> >> + * Copyright (c) 2014-2015 Mentor Graphics Inc.
> >> + *
> >> + * This program is free software; you can redistribute it and/or modify
> >> + * it under the terms of the GNU General Public License as published by
> >> the + * Free Software Foundation; either version 2 of the
> >> + * License, or (at your option) any later version
> >> + */
> >> +
> >> +#ifndef __UAPI_MEDIA_IMX_H__
> >> +#define __UAPI_MEDIA_IMX_H__
> >> +
> >> +/*
> >> + * events from the subdevs
> >> + */
> >> +#define V4L2_EVENT_IMX_CLASS          V4L2_EVENT_PRIVATE_START
> >> +#define V4L2_EVENT_IMX_NFB4EOF        (V4L2_EVENT_IMX_CLASS + 1)
> >> +#define V4L2_EVENT_IMX_EOF_TIMEOUT    (V4L2_EVENT_IMX_CLASS + 2)
> >> +#define V4L2_EVENT_IMX_FRAME_INTERVAL (V4L2_EVENT_IMX_CLASS + 3)
> > 
> > Aren't these generic enough to warrant common events? I would think
> > there have to be other capture IP cores that can signal aborted frames
> > or frame timeouts.
> 
> Yes, agreed. A frame capture timeout, or frame interval error, are
> both generic concepts. At some point it would be great to make the
> Frame Interval Monitor generally available under v4l2-core. As for the
> EOF timeout event, I'll look into moving that into a generic V4L2 event.

I'd prefer generic events if possible, but regardless of whether that's 
possible, the events must be documented in the V4L2 specification.

-- 
Regards,

Laurent Pinchart