From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH v3 1/4] drm/bridge: Add RGB to VGA bridge support Date: Mon, 19 Sep 2016 11:23:16 +0200 Message-ID: <20160919092316.GH8719@lukather> References: <20160908121751.16911-1-maxime.ripard@free-electrons.com> <20160908121751.16911-2-maxime.ripard@free-electrons.com> <2115773.yQojqqIjGI@avalon> <1682784.hDdFQltm22@avalon> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Dx9iWuMxHO1cCoFc" Return-path: Content-Disposition: inline In-Reply-To: <1682784.hDdFQltm22@avalon> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Laurent Pinchart Cc: dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Chen-Yu Tsai , Rob Herring , Daniel Vetter , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org --Dx9iWuMxHO1cCoFc Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Sep 18, 2016 at 01:04:17PM +0300, Laurent Pinchart wrote: > On Sunday 18 Sep 2016 13:01:16 Laurent Pinchart wrote: > > On Thursday 08 Sep 2016 14:17:48 Maxime Ripard wrote: > > > Some boards have an entirely passive RGB to VGA bridge, based on eith= er > > > DACs or resistor ladders. > > >=20 > > > Those might or might not have an i2c bus routed to the VGA connector = in > > > order to access the screen EDIDs. > > >=20 > > > Add a bridge that doesn't do anything but expose the modes available = on > > > the screen, either based on the EDIDs if available, or based on the X= GA > > > standards. > > >=20 > > > Acked-by: Rob Herring > > > Signed-off-by: Maxime Ripard > > > --- > > >=20 > > > .../bindings/display/bridge/rgb-to-vga-bridge.txt | 52 +++++ > > > drivers/gpu/drm/bridge/Kconfig | 6 + > > > drivers/gpu/drm/bridge/Makefile | 1 + > > > drivers/gpu/drm/bridge/rgb-to-vga.c | 232 +++++++++++= +++++ > > > 4 files changed, 291 insertions(+) > > > create mode 100644 > > >=20 > > > Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt > > > create mode 100644 drivers/gpu/drm/bridge/rgb-to-vga.c > > >=20 > > > diff --git > > > a/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.= txt > > > b/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.= txt > > > new file mode 100644 > > > index 000000000000..83a053fb51a0 > > > --- /dev/null > > > +++ > > > b/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.= txt > > > @@ -0,0 +1,52 @@ > > > +Passive RGB to VGA bridge > > > +------------------------- > > > + > > > +This binding is aimed for entirely passive RGB to VGA bridges that d= o not > > > +require any configuration. > >=20 > > Couldn't it also support active RGB to VGA bridges that don't require a= ny > > configuration ? It would seem a bit pointless to define a separate DT > > binding for them. >=20 > I'm thinking in particular about the ADV7123 > (http://www.analog.com/media/en/technical-documentation/data-sheets/ADV71= 23.pdf) > that already has a DT binding. I guess we don't have the same definition of passive, but I was thinking of devices that do not need any configuration in order to operate properly. And this one seems to fall in that category. > Would it be feasible to combine the two, and support both devices > with a single driver ? I don't see why not. But converting the renesas DRM driver seems a bit out of scope, and the ADV compatible can definitely be added later. Maxime --=20 Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com --Dx9iWuMxHO1cCoFc Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJX366EAAoJEBx+YmzsjxAgHi8QALSFzRmTPZIaXuzOYyXybGoM T4x4R97e5W9cQFRp2nD0gPquyJvYRJe37HJv8WcfsmfajRzXOHkC0Tzb1f5leEV8 4DJ+BEkPLFZ2L+h3WkUAIkboD99tW60VWHE1UdIob+o8EDaKPldPExwCtX5D6F/l tjuozgMLGXAkA2oVQDYYghpNpIPM6kF8nYn4897KtrSRkKZh8egE/QBXhoaEuAuS 8cOgezn3y+qff1F4aiUY4FquZzzGEN5xtS69qds3BtLtS/IlyqMEyLZASyNjpN5d GmcpVNd7nyjVQCRxGoNSwoJyc3uh3TmTJuCh0BQu63pYxoQPLaxENtoktKHIVP/W tprJJKe1KSpi1I21WpSe8wNA5am8AaMLYWmKfi7ZlqGxH6e5rz+2a9mmKuPtNJlX ReR6iMZP2DowQCm283LIYko64/6Ie2os7JA5SYCdGy/JBw8d4isma2BhUS995tEi R1FGgOgfL3UcUqDZRzBzJpDHLE0g1f2pUJYgHFfWM9vpKpN9NE/f/aeOdoGnYG0j fXQDyX1r9P2VmeQfl6Wy3lx6IUUUBulTSgUGZRkA2VA204papFP0eDe9AiUBd8AC y/zvUM2J3jFTBKDsL/ezVlvIDtdNQl7y1hbDseqj5SoaeAqSWwHdB7XCgxPUMjjo iTQXGx6XRhi6RWkz+i1V =z2TS -----END PGP SIGNATURE----- --Dx9iWuMxHO1cCoFc-- -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.ripard@free-electrons.com (Maxime Ripard) Date: Mon, 19 Sep 2016 11:23:16 +0200 Subject: [PATCH v3 1/4] drm/bridge: Add RGB to VGA bridge support In-Reply-To: <1682784.hDdFQltm22@avalon> References: <20160908121751.16911-1-maxime.ripard@free-electrons.com> <20160908121751.16911-2-maxime.ripard@free-electrons.com> <2115773.yQojqqIjGI@avalon> <1682784.hDdFQltm22@avalon> Message-ID: <20160919092316.GH8719@lukather> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sun, Sep 18, 2016 at 01:04:17PM +0300, Laurent Pinchart wrote: > On Sunday 18 Sep 2016 13:01:16 Laurent Pinchart wrote: > > On Thursday 08 Sep 2016 14:17:48 Maxime Ripard wrote: > > > Some boards have an entirely passive RGB to VGA bridge, based on either > > > DACs or resistor ladders. > > > > > > Those might or might not have an i2c bus routed to the VGA connector in > > > order to access the screen EDIDs. > > > > > > Add a bridge that doesn't do anything but expose the modes available on > > > the screen, either based on the EDIDs if available, or based on the XGA > > > standards. > > > > > > Acked-by: Rob Herring > > > Signed-off-by: Maxime Ripard > > > --- > > > > > > .../bindings/display/bridge/rgb-to-vga-bridge.txt | 52 +++++ > > > drivers/gpu/drm/bridge/Kconfig | 6 + > > > drivers/gpu/drm/bridge/Makefile | 1 + > > > drivers/gpu/drm/bridge/rgb-to-vga.c | 232 ++++++++++++++++ > > > 4 files changed, 291 insertions(+) > > > create mode 100644 > > > > > > Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt > > > create mode 100644 drivers/gpu/drm/bridge/rgb-to-vga.c > > > > > > diff --git > > > a/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt > > > b/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt > > > new file mode 100644 > > > index 000000000000..83a053fb51a0 > > > --- /dev/null > > > +++ > > > b/Documentation/devicetree/bindings/display/bridge/rgb-to-vga-bridge.txt > > > @@ -0,0 +1,52 @@ > > > +Passive RGB to VGA bridge > > > +------------------------- > > > + > > > +This binding is aimed for entirely passive RGB to VGA bridges that do not > > > +require any configuration. > > > > Couldn't it also support active RGB to VGA bridges that don't require any > > configuration ? It would seem a bit pointless to define a separate DT > > binding for them. > > I'm thinking in particular about the ADV7123 > (http://www.analog.com/media/en/technical-documentation/data-sheets/ADV7123.pdf) > that already has a DT binding. I guess we don't have the same definition of passive, but I was thinking of devices that do not need any configuration in order to operate properly. And this one seems to fall in that category. > Would it be feasible to combine the two, and support both devices > with a single driver ? I don't see why not. But converting the renesas DRM driver seems a bit out of scope, and the ADV compatible can definitely be added later. Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: not available URL: