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From: Marco Felsch <m.felsch@pengutronix.de>
To: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Hans Verkuil <hverkuil@xs4all.nl>,
	sakari.ailus@linux.intel.com, hans.verkuil@cisco.com,
	jacopo+renesas@jmondi.org, robh+dt@kernel.org,
	laurent.pinchart@ideasonboard.com, linux-media@vger.kernel.org,
	devicetree@vger.kernel.org, kernel@pengutronix.de,
	Rob Herring <robh@kernel.org>
Subject: Re: [PATCH v6 01/13] dt-bindings: connector: analog: add tv norms property
Date: Fri, 9 Aug 2019 08:00:37 +0200
Message-ID: <20190809060037.pauihgtyrom7nhmg@pengutronix.de> (raw)
In-Reply-To: <20190514151119.2099cd10@coco.lan>

Hi Mauro, Hans,

thanks for the review.

On 19-05-14 15:11, Mauro Carvalho Chehab wrote:
> Em Mon, 6 May 2019 12:01:06 +0200
> Hans Verkuil <hverkuil@xs4all.nl> escreveu:
> 
> > On 4/15/19 2:44 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.  
> > 
> > For S-Video and Composite connectors there are really just two formats
> > to consider: 50 and 60 Hz. I.e. there is no difference between PAL
> > and SECAM. Only for tuners/modulators does this matter.
> > 
> > So it is a good idea to add TVNORM_525_60, TVNORM_625_50 to tvnorms.h.

Of course I can add this ones. With Mauro's concerns below do you still
think that it is a good idea to adapt the example?

Regards,
  Marco

> > In the various bindings examples I would recommend that you use
> > TVNORM_525_60 or TVNORM_625_50 rather than e.g. PAL_M since that's what
> > you would use in practice for Composite/S-Video.
> 
> Hans, that could be true for component video, but for S-Video and
> Composite, you need to tell the demod how the color sub-carrier is
> encoded, and what's its frequency, or otherwise it won't work.
> 
> There are plenty of equipments in Brazil that have both NTSC/M and
> PAL/M (and a few with PAL/N') output. All those formats are 60Hz.
> 
> Colors are only decoded by tvp5150 and other demods if it is set
> to the right color format (PAL or NTSC) and to the right line 
> frequency (60Hz) [1]. Also, some decoders are very sensitive to the
> chroma sub-carrier frequency. That's the case of tvp5150.
> 
> [1] Or - when supported by the hardware - if the demod is set to
>     automatic mode.
> 
>     Automatic mode usually doesn't work well with PAL/M and PAL/N'.
> 
>     The problem is related to the sub-carrier frequency: both 
>     PAL/N' (used only on Paraguay) and NTSC/M have the same 
>     frequency; PAL/M has a close but different frequency for the
>     color sub-carrier.
> 
>     Most decoders use the frequency of the chroma sub-carrier in
>     order to switch between NTSC/M nd PAL/M. So, auto-detection
>     usually fails with PAL/N', as such detectors understand it
>     as NTSC.
> 
>     Worse than that, it is not uncommon to have pseudo-PAL-M devices
>     that were made for the US market, and received a conversion
>     to PAL, with envolves adding a small board with a NTSC->PAL converter.
>     As most TV sets used in this part of the world are designed to
>     work both with PAL/M and PAL/N' (by using a broader notch filter),
>     to make the hardware cheaper, lots of manufacturers just
>     change the modulation on encoders, while keeping the NTSC XTAL.
>     So, in practice, such devices, sold as "PAL/M" are actually PAL/N'.
>     A significant amount of old VCRs and DVD devices found in Brazil
>     are actually PAL/N'. The same applies to game consoles.
> 
>     Btw, the main reason for having analog video streams here nowadays
>     is to copy old videos from VCRs and encode them digitally or to
>     record games from game consoles.
> 
> > 
> > Regards,
> > 
> > 	Hans
> > 
> > > 
> > > 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.felsch@pengutronix.de>
> > > Reviewed-by: Rob Herring <robh@kernel.org>
> > > ---
> > > [1] https://patchwork.kernel.org/cover/10794703/
> > > 
> > > 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           | 56 +++++++++++++++++++
> > >  2 files changed, 60 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..346f8937a0b7 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
> > > +           all tv norms are allowed. Possible video standards are defined in
> > > +           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_M | TVNORM_NTSC_M)>;
> > >  
> > >  	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..058ab8414145
> > > --- /dev/null
> > > +++ b/include/dt-bindings/media/tvnorms.h
> > > @@ -0,0 +1,56 @@
> > > +/* SPDX-License-Identifier: GPL-2.0-only or X11 */
> > > +/*
> > > + * Copyright 2019 Pengutronix, Marco Felsch <kernel@pengutronix.de>
> > > + */
> > > +
> > > +#ifndef _DT_BINDINGS_MEDIA_TVNORMS_H
> > > +#define _DT_BINDINGS_MEDIA_TVNORMS_H
> > > +
> > > +/* one bit for each */
> > > +#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_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)
> > > +
> > > +#endif /* _DT_BINDINGS_MEDIA_TVNORMS_H */
> 
> Patch looks good to me.
> 
> Thanks,
> Mauro
> 

-- 
Pengutronix e.K.                           |                             |
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  reply index

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-15 12:44 [PATCH v6 00/13] TVP5150 new features Marco Felsch
2019-04-15 12:44 ` [PATCH v6 01/13] dt-bindings: connector: analog: add tv norms property Marco Felsch
2019-05-06 10:01   ` Hans Verkuil
2019-05-06 10:06     ` Hans Verkuil
2019-05-14 18:11     ` Mauro Carvalho Chehab
2019-08-09  6:00       ` Marco Felsch [this message]
2019-05-16 16:27   ` Laurent Pinchart
2019-08-09  5:58     ` Marco Felsch
2019-08-15 12:33       ` Laurent Pinchart
2019-08-15 12:50         ` Marco Felsch
2019-08-15 13:02           ` Laurent Pinchart
2019-08-15 13:35             ` Marco Felsch
2019-04-15 12:44 ` [PATCH v6 02/13] media: v4l2-fwnode: add v4l2_fwnode_connector Marco Felsch
2019-05-06  9:50   ` Hans Verkuil
2019-05-14 18:17     ` Mauro Carvalho Chehab
2019-08-09  7:20     ` Marco Felsch
2019-05-16 16:36   ` Laurent Pinchart
2019-08-09  7:55     ` Marco Felsch
2019-08-15 12:38       ` Laurent Pinchart
2019-08-15 13:04         ` Marco Felsch
2019-08-15 13:10           ` Laurent Pinchart
2019-08-15 13:37             ` Marco Felsch
2019-04-15 12:44 ` [PATCH v6 03/13] media: v4l2-fwnode: add initial connector parsing support Marco Felsch
2019-05-06 10:10   ` Hans Verkuil
2019-05-14 18:20     ` Mauro Carvalho Chehab
2019-05-16 16:51       ` Laurent Pinchart
2019-08-09 12:16         ` Marco Felsch
2019-08-15 12:48           ` Laurent Pinchart
2019-08-15 13:14             ` Marco Felsch
2019-08-09  8:59       ` Marco Felsch
2019-04-15 12:44 ` [PATCH v6 04/13] partial revert of "[media] tvp5150: add HW input connectors support" Marco Felsch
2019-04-15 12:44 ` [PATCH v6 05/13] media: tvp5150: add input source selection of_graph support Marco Felsch
2019-05-06 10:09   ` Jacopo Mondi
2019-05-14 18:25   ` Mauro Carvalho Chehab
2019-05-16 18:03     ` Laurent Pinchart
2019-08-13  8:54       ` Marco Felsch
2019-08-15 12:51         ` Laurent Pinchart
2019-08-15 13:22           ` Marco Felsch
2019-08-15 13:26             ` Laurent Pinchart
2019-04-15 12:44 ` [PATCH v6 06/13] media: dt-bindings: tvp5150: Add input port connectors DT bindings Marco Felsch
2019-05-14 18:27   ` Mauro Carvalho Chehab
2019-05-16 18:05   ` Laurent Pinchart
2019-08-13  8:56     ` Marco Felsch
2019-04-15 12:44 ` [PATCH v6 07/13] media: tvp5150: add FORMAT_TRY support for get/set selection handlers Marco Felsch
2019-05-06 13:36   ` Jacopo Mondi
2019-08-09  5:33     ` Marco Felsch
2019-05-14 18:48   ` Mauro Carvalho Chehab
2019-08-09  5:34     ` Marco Felsch
2019-04-15 12:44 ` [PATCH v6 08/13] media: tvp5150: initialize subdev before parsing device tree Marco Felsch
2019-05-14 20:20   ` Mauro Carvalho Chehab
2019-08-09  5:42     ` Marco Felsch
2019-04-15 12:44 ` [PATCH v6 09/13] media: tvp5150: add s_power callback Marco Felsch
2019-05-14 20:13   ` Mauro Carvalho Chehab
2019-08-09  5:39     ` Marco Felsch
2019-04-15 12:44 ` [PATCH v6 10/13] media: dt-bindings: tvp5150: cleanup bindings stlye Marco Felsch
2019-04-15 12:44 ` [PATCH v6 11/13] media: dt-bindings: tvp5150: add optional tvnorms documentation Marco Felsch
2019-04-15 12:44 ` [PATCH v6 12/13] media: tvp5150: add support to limit tv norms on connector Marco Felsch
2019-05-16 18:07   ` Laurent Pinchart
2019-08-13  9:10     ` Marco Felsch
2019-08-15 12:53       ` Laurent Pinchart
2019-08-15 13:26         ` Marco Felsch
2019-04-15 12:44 ` [PATCH v6 13/13] media: tvp5150: make debug output more readable Marco Felsch
2019-05-06 13:39   ` Jacopo Mondi
2019-05-14 20:18     ` Mauro Carvalho Chehab
2019-08-09  5:42       ` Marco Felsch
2019-05-06  5:47 ` [PATCH v6 00/13] TVP5150 new features Marco Felsch
2019-05-14 17:18   ` Mauro Carvalho Chehab
2019-05-14 20:20     ` Mauro Carvalho Chehab
2019-05-14 20:58       ` Marco Felsch
2019-05-14 23:41         ` Mauro Carvalho Chehab

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