On 19-08-19 10:39, Hans Verkuil wrote:
> On 8/19/19 10:09 AM, Marco Felsch wrote:
> > Hi Hans,
> >
> > On 19-08-16 13:11, Hans Verkuil wrote:
> >> On 8/15/19 1:57 PM, Marco Felsch wrote:
> >>> Some connectors no matter if in- or output supports only a limited
> >>> range of tv norms. It doesn't matter if the hardware behind that
> >>> connector supports more than the listed formats since the users are
> >>> restriced by a label e.g. to plug only a camera into this connector
> >>> which uses the PAL format.
> >>>
> >>> This patch adds the capability to describe such limitation within the
> >>> firmware. There are no format restrictions if the property isn't
> >>> present, so it's completely backward compatible.
> >>>
> >>> Signed-off-by: Marco Felsch <m.fel...@pengutronix.de>
> >>> Reviewed-by: Rob Herring <r...@kernel.org>
> >>> ---
> >>> [1] https://patchwork.kernel.org/cover/10794703/
> >>>
> >>> v7:
> >>> I kept Robs r b tag because I only changed the example and extended
> >>> TVNORM_* macros.
> >>>
> >>> - fix some style issues
> >>> - add TVNORM_NTSC, TVNORM_525_60 and TVNORM_625_50
> >>>
> >>> v6:
> >>> - tvnorms.h: use tabs instead of spaces
> >>> - tvnorms.h: add TVNORM_PAL and TVNORM_SECAM
> >>> - tvnorms.h: drop rarely used TVNORM_ATSC_* norms
> >>>
> >>> v2-v4:
> >>> - nothing since the patch was squashed from series [1] into this
> >>> series.
> >>> ---
> >>> .../display/connector/analog-tv-connector.txt | 4 ++
> >>> include/dt-bindings/media/tvnorms.h | 72 +++++++++++++++++++
> >>> 2 files changed, 76 insertions(+)
> >>> create mode 100644 include/dt-bindings/media/tvnorms.h
> >>>
> >>> diff --git
> >>> a/Documentation/devicetree/bindings/display/connector/analog-tv-connector.txt
> >>>
> >>> b/Documentation/devicetree/bindings/display/connector/analog-tv-connector.txt
> >>> index 0c0970c210ab..434e8aa0398b 100644
> >>> ---
> >>> a/Documentation/devicetree/bindings/display/connector/analog-tv-connector.txt
> >>> +++
> >>> b/Documentation/devicetree/bindings/display/connector/analog-tv-connector.txt
> >>> @@ -6,6 +6,9 @@ Required properties:
> >>>
> >>> Optional properties:
> >>> - label: a symbolic name for the connector
> >>> +- tvnorms: limit the supported tv norms on a connector to the given ones
> >>> else
> >>
> >> tv -> TV
> >>
> >>> + all tv norms are allowed. Possible video standards are
> >>> defined in
> >>
> >> tv -> TV
> >
> > Changed both thanks.
> >
> >> And a more high-level question: I think tvnorm is a very vague name. It's
> >> a term
> >> used in media, but what does 'norm' mean anyway? 'tv_standards' or
> >> 'video_standards'
> >> would be a lot more descriptive.
> >
> > I'm with you *_standards would be more descriptive. Now the question is:
> > is it a video or a tv standard? Wikipedia says that SECAM, PAL, NTSC is
> > a television standard. So I prefer the 'tv_standards' or better the
> > 'tv-standards' approach.
>
> It's a bit of both, actually. But in the context of S-Video and Composite
> connectors
> it is a video standard. In the context of a tuner/modulator it would be a TV
> standard.
>
> I.e. there is no difference between PAL_B and PAL_[GHIDJ] when it comes to
> S-Video and
> Composite connectors, but in the context of a tuner/modulator these defines
> give
> additional information about transmission bands, etc.
>
> That said, I think video-standards is too vague, but so is tv-standards. How
> about
> sdtv-standards? I think that makes a lot of sense since this is really just
> for SDTV.
Yes, thats a good name.
> So tvnorms.h becomes sdtv-standards.h.
Of course.
> >
> >> 'tvnorm' is, I think, a term used only internally in the media subsystem
> >> for no
> >> clear reason. In the V4L2 spec it talks about 'video standard'.
> >>
> >> Sorry for being so late with raising this issue.
> >>
> >>> + include/dt-bindings/media/tvnorms.h.
> >>>
> >>> Required nodes:
> >>> - Video port for TV input
> >>> @@ -16,6 +19,7 @@ Example
> >>> tv: connector {
> >>> compatible = "composite-video-connector";
> >>> label = "tv";
> >>> + tvnorms = <(TVNORM_PAL | TVNORM_NTSC)>;
> >>>
> >>> port {
> >>> tv_connector_in: endpoint {
> >>> diff --git a/include/dt-bindings/media/tvnorms.h
> >>> b/include/dt-bindings/media/tvnorms.h
> >>> new file mode 100644
> >>> index 000000000000..e1275673c4d6
> >>> --- /dev/null
> >>> +++ b/include/dt-bindings/media/tvnorms.h
> >>> @@ -0,0 +1,72 @@
> >>> +/* SPDX-License-Identifier: GPL-2.0-only or X11 */
> >>> +/*
> >>> + * Copyright 2019 Pengutronix, Marco Felsch <ker...@pengutronix.de>
> >>> + */
> >>> +
> >>> +#ifndef _DT_BINDINGS_MEDIA_TVNORMS_H
> >>> +#define _DT_BINDINGS_MEDIA_TVNORMS_H
> >>> +
> >>> +/* One bit for each standard */
> >>
> >> I would add a comment here and in videodev2.h where you mention that
> >> the two headers should remain in sync.
> >
> > Yes, good point.
> >
> >>> +#define TVNORM_PAL_B 0x00000001
> >>> +#define TVNORM_PAL_B1 0x00000002
> >>> +#define TVNORM_PAL_G 0x00000004
> >>> +#define TVNORM_PAL_H 0x00000008
> >>> +#define TVNORM_PAL_I 0x00000010
> >>> +#define TVNORM_PAL_D 0x00000020
> >>> +#define TVNORM_PAL_D1 0x00000040
> >>> +#define TVNORM_PAL_K 0x00000080
> >>> +
> >>> +#define TVNORM_PAL (TVNORM_PAL_B | \
> >>> + TVNORM_PAL_B1 | \
> >>> + TVNORM_PAL_G | \
> >>> + TVNORM_PAL_H | \
> >>> + TVNORM_PAL_I | \
> >>> + TVNORM_PAL_D | \
> >>> + TVNORM_PAL_D1 | \
> >>> + TVNORM_PAL_K)
> >>> +
> >>> +#define TVNORM_PAL_M 0x00000100
> >>> +#define TVNORM_PAL_N 0x00000200
> >>> +#define TVNORM_PAL_Nc 0x00000400
> >>> +#define TVNORM_PAL_60 0x00000800
> >>> +
> >>> +#define TVNORM_NTSC_M 0x00001000 /* BTSC */
> >>> +#define TVNORM_NTSC_M_JP 0x00002000 /* EIA-J */
> >>> +#define TVNORM_NTSC_443 0x00004000
> >>> +#define TVNORM_NTSC_M_KR 0x00008000 /* FM A2 */
> >>> +
> >>> +#define TVNORM_NTSC (TVNORM_NTSC_M |\
> >>> + TVNORM_NTSC_M_JP |\
> >>
> >> Add space before \
> >>
> >>> + TVNORM_NTSC_M_KR)
> >>> +
> >>> +#define TVNORM_SECAM_B 0x00010000
> >>> +#define TVNORM_SECAM_D 0x00020000
> >>> +#define TVNORM_SECAM_G 0x00040000
> >>> +#define TVNORM_SECAM_H 0x00080000
> >>> +#define TVNORM_SECAM_K 0x00100000
> >>> +#define TVNORM_SECAM_K1 0x00200000
> >>> +#define TVNORM_SECAM_L 0x00400000
> >>> +#define TVNORM_SECAM_LC 0x00800000
> >>> +
> >>> +#define TVNORM_SECAM (TVNORM_SECAM_B | \
> >>> + TVNORM_SECAM_D | \
> >>> + TVNORM_SECAM_G | \
> >>> + TVNORM_SECAM_H | \
> >>> + TVNORM_SECAM_K | \
> >>> + TVNORM_SECAM_K1 | \
> >>> + TVNORM_SECAM_L | \
> >>> + TVNORM_SECAM_LC)
> >>> +
> >>> +/* Standards for Countries with 60Hz Line frequency */
> >>> +#define TVNORM_525_60 (TVNORM_PAL_M | \
> >>> + TVNORM_PAL_60 | \
> >>> + TVNORM_NTSC | \
> >>> + TVNORM_NTSC_443)
> >>> +
> >>> +/* Standards for Countries with 50Hz Line frequency */
> >>> +#define TVNORM_625_50 (TVNORM_PAL |\
> >>> + TVNORM_PAL_N |\
> >>> + TVNORM_PAL_Nc |\
> >>
> >> Add space before \
> >
> > Both space errors fixed.
> >
> >>> + TVNORM_SECAM)
> >>> +
> >>> +#endif /* _DT_BINDINGS_MEDIA_TVNORMS_H */
> >>>
> >>
> >> I was also wondering if this header shouldn't be in
> >> include/dt-bindings/display/
> >> since the bindings are also described in 'display'.
> >
> > That's a good one and I really don't know which is the 'right' place for
> > it. Since the standard has nothing to do with a display I would keep it
> > within media. But the radeon [1] gpu uses the stds too. So I really
> > don't know which place is better.
>
> Move it to display: that matches where the documentation is.
Okay.
>
> Note that this means that _DT_BINDINGS_MEDIA_TVNORMS_H also becomes
> _DT_BINDINGS_DISPLAY_TVNORMS_H (or DISPLAY_SDTV_STANDARDS_H).
Yes.
Last question. I replaced TVNORM_* by TV_STD_*. Should I move to
SDTV_STD_* too?
Regards,
Marco
> Regards,
>
> Hans
>
> >
> > [1] drivers/gpu/drm/radeon/radeon_mode.h.
> >
> > Regards,
> > Marco
> >
> >> Regards,
> >>
> >> Hans
> >>
> >
>
>
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