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.
So tvnorms.h becomes sdtv-standards.h.
>
>> '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.
Note that this means that _DT_BINDINGS_MEDIA_TVNORMS_H also becomes
_DT_BINDINGS_DISPLAY_TVNORMS_H (or DISPLAY_SDTV_STANDARDS_H).
Regards,
Hans
>
> [1] drivers/gpu/drm/radeon/radeon_mode.h.
>
> Regards,
> Marco
>
>> Regards,
>>
>> Hans
>>
>
