From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Subject: Re: OMAPDSS and panel-dpi Date: Tue, 22 Apr 2014 16:28:12 +0300 Message-ID: <1398173292.5897.16.camel@deskari> References: <20140417192215.GA24931@atomide.com> <20140417225025.GA25732@atomide.com> <20140418025024.GB25732@atomide.com> <20140418154015.GA5354@atomide.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-kIk4oP5gGAa9onQgTp6y" Return-path: Received: from comal.ext.ti.com ([198.47.26.152]:58884 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750955AbaDVN2R (ORCPT ); Tue, 22 Apr 2014 09:28:17 -0400 In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Joachim Eastwood Cc: Tony Lindgren , linux-omap@vger.kernel.org --=-kIk4oP5gGAa9onQgTp6y Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2014-04-18 at 18:43 +0200, Joachim Eastwood wrote: > > If it does not make sense to set up a generic mode-gpios for the > > panels, then panel dpi can parse the first two GPIOs for enable > > and reset. Then we can allow the rest of the array be parsed if > > needed based on the compatible flag. >=20 > Looking through the panels in omap2/display-new the most common gpio > pins are; backlight, reset and enable. > So it makes sense to have enable and reset as properties. >=20 > Gpio is used for mode setting in: nl8048hl11 and ls037v7dw01. > nl8048hl11 has just a qvga gpio, while the other one has no less than > 3 mode pins (qvga and 2 scanning direction pins). All these mode pins > are set once and then never touched again. >=20 > Using gpios property for setting up an arbitrary amount of mode pins > so like a solution to me. Generic reset gpio handling is a bit problematic, as even if we know what the normal state for the gpio is, we don't know how to use it. How long should it be set to reset-state? How long should be it in the normal-state before we can reset again? How to handle the powers when resetting? We could have some big delays there, which would work for more or less all the panels. It just doesn't feel quite right =3D). If we need reset and panel specific mode pin handling, I think a separate driver is the cleanest option. Do we have any way to set some gpios to a specified value at boot time via DT, in a fixed manner? So more or less what Tony does in ldp_twl_gpio_setup(). If we could just fix the RESET and QVGA gpios, we could use the panel-dpi just fine, and only handle the enable gpio in the panel driver. Tomi --=-kIk4oP5gGAa9onQgTp6y Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAABAgAGBQJTVm5sAAoJEPo9qoy8lh71MxQQAK87LAa+4IW7Uy3m5Ds3sojy XKM8xc7gML6NK6xQDuYrjrZAD4WG1S6FHIXeclM+mdUSiKL5eMr8TzmpdMLEn6Hq IHAh9LWTBYN2z5HcGaU3UTVY6osrWMiX6r1DLRwcVS+NuT8dQ6gcsWObEW20YueU 3ntY7IrBmvtQYjKkDHQMvpRi78UoGzMeJRKgicMpLALreKvyM4QUyyJdepSZyKWf XQhnfyePFUCtTFWxhUEAIKPxk8P8/MAqnDDfnLHX0Ubxe2WLvx39SmBO1VvlZOfp 5IejnhPcaDcF0JMQakkCYxxbn9p4WmtTGl5VnRAMdu7fBnd10B5vtga3eIpRE7iL KT0N/g/tHJ8gF7aWdPL75farLqVCfXl8E2H9smmIOEUTcqu43dGH5ewIcJx0HZaV AzGUQnqIpNy9Rza5k79w2PQ69gOvJbpJazBTe/hXvJXIFxWmzQaj7ovXjGU2Ipme +j39/kNG7cGGOQuIMY52U5mTkyfvdO5xG4wCvy52hr8PbT+P+DqehoY3Jh9nxpeG GgCX8OKFDlma35bj6yyC/7YtFxCUE3ZPaT0fxiTs/ku0O4lBF7KHLq9/KOz5u+Je jtR53pibkld56aUpp9UIUIXOghy1+41h/Jl/LMvkEkZw6TYcvXNyDVCOhIRThwvz pdT0NCs/9giQgzpU/G1k =zmgt -----END PGP SIGNATURE----- --=-kIk4oP5gGAa9onQgTp6y--