On 19-08-15 15:33, Laurent Pinchart wrote:
> Hi Marco,
> 
> On Fri, Aug 09, 2019 at 07:58:09AM +0200, Marco Felsch wrote:
> > On 19-05-16 19:27, Laurent Pinchart wrote:
> > > On Mon, Apr 15, 2019 at 02:44:01PM +0200, 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.
> > > 
> > > Why is this needed ? It's not really a hardware property, is it ? What's
> > > the use case ?
> > 
> > Cause some hardware only support a limited range of formats to that
> > connector. Of course it is a hardware property. For example if a
> > customer wants to limit a connector to a specifc norm because the
> > hardware behind that connector only supports that format or is
> > restricted to that format.
> 
> Then it should be a DT property of the hardware behind that connector
> (or information hardcoded directly into that driver), shouldn't it ?

Why? The connector is the limiting factor and not the decoder/bridge
device behind that. Let me explain it a bit more in detail. Our customer
sells hardware boxes and cameras. The camera is connected to the box
using a custom plug. So it's guaranteed that only their cameras can be
connected to. Also the camera they are using supports only PAL. So the
PAL signal is the only one which can be received on that connector. The
TVP itself supports more than just PAL signals and has multiple inputs.
So there can be the use case that a hardware box supports two physical
connectors: e.g. connector-PAL, connector-NTSC. The TVP should be
limited to PAL signals if the connector-PAL is active or limited to NTSC
if the connector-NTSC is active.

Hopefully you see now why we should model it on the connector side and
not on the device behind that connector.

Regards,
  Marco

> > > > Signed-off-by: Marco Felsch <m.fel...@pengutronix.de>
> > > > Reviewed-by: Rob Herring <r...@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 <ker...@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 */
> 
> -- 
> Regards,
> 
> Laurent Pinchart
> 

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Reply via email to