On 8/19/19 11:01 AM, Marco Felsch wrote:
> 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?
I think so, yes.
Regards,
Hans
>
> Regards,
> Marco
>
>> Regards,
>>
>> Hans
>>
>>>
>>> [1] drivers/gpu/drm/radeon/radeon_mode.h.
>>>
>>> Regards,
>>> Marco
>>>
>>>> Regards,
>>>>
>>>> Hans
>>>>
>>>
>>
>>
>
