From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Date: Wed, 24 Feb 2016 11:47:36 +0000 Subject: Re: [PATCH 11/11] ARM: versatile: move CLCD configuration to device tree Message-Id: <56CD9858.40104@ti.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="3jb4dx1J7KmXxJb9HW2s84SP0FvRL8nTA" List-Id: References: <1454594660-7532-1-git-send-email-linus.walleij@linaro.org> <1454594660-7532-12-git-send-email-linus.walleij@linaro.org> <56CC2D39.80909@ti.com> <56CC546A.9070705@ti.com> <20160224104638.GL19428@n2100.arm.linux.org.uk> <56CD924F.50108@ti.com> <20160224113549.GN19428@n2100.arm.linux.org.uk> In-Reply-To: <20160224113549.GN19428@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org --3jb4dx1J7KmXxJb9HW2s84SP0FvRL8nTA Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 24/02/16 13:35, Russell King - ARM Linux wrote: > If the connector is a flexi-strip or LVDS connector designed to be > connected directly to a panel, it is not designed as a user connector, > and the display can be regarded as part of the board: the connector > probably isn't rated for a large number of mating cycles. >=20 > If the connector is a board-edge external-unit connector, then the > panel is not part of the board. Ok, I see. I presumed the display-board was attached directly to the mainboard. Of course, we could still argue about the difference, with the exact same pins used with an external connector and with an on-board connector, but lets not go there. I agree in this case the panels are external devices =3D). However, I would still be interested in opinions how to implement the exact same case, but for boards where the panels were considered on-board panels. > The displays are not built for "this single board" but for a family of > boards: not only Versatile PB/AB, but also the Realview family of board= s > too. Alright. So, if this is to be done correctly, we need to disconnect the display board code from the CLCD code, as they really have nothing to do with each other. Perhaps a panel driver which covers the display boards used here, which does the probing and contains the video timings for the panels in questio= n? One could then use that panel driver with other display controllers too. Although the probing part is perhaps difficult to make generic, but that board specific code should still be part of the panel-board driver, not CLCD driver. >> But I cannot accept that as a general solution for all similar cases >> going forward, especially when moving to DRM world, that's just bad SW= >> design. >=20 > I think that's a matter of personal opinion, perspective and situation.= > What is good design today is not necessary good design yesterday or > tomorrow. I thought we already ascertained that earlier in this > discussion. :) Well, I was mostly referring to combining separate devices into single driver. CLCD and the external displays, in this case. Then again, "complexity" is part of the SW design, and splitting the devices drivers into independent pieces often increases complexity, so... Tomi --3jb4dx1J7KmXxJb9HW2s84SP0FvRL8nTA Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJWzZhYAAoJEPo9qoy8lh71a3YP/0+g7sXV42QRt0wHT+d4pO5X d++txhXeKB+h/SXbLiXpno+R0qTWY5YpvXSmAzJbo0AbRGaa8oWXmhOUlpVFeW6t BFst/9Zfg3f0oboSRMXx/DD8jwbZlNI4YAp6ZTiCY/8tWCbrjqFV1zz2ye8+lTF8 ZQLzatDzB3JpWC8D2XwKzBbeJaQhU0Tuz+6oT+5ljPe5XSuleU7TRNlWhvUQkXCI peg0dxPo2NtkMfd/VCH9h2rmM6pyrggZi8wU/RDNF6dCHXUlCKsCtGDecD8wH//g pYGB5vgYm8Z5a/4PSq3QN4eHPwt3WxJinaIhq1NP9+5jLk1uM+GF07AkQa5gdAXy 9DYwKuJUPs35xll8RjD+3CTaG2PnluqaMSxx+NvxzpbfsY5Fl5FQX/U1CO2gY0zd NehyZkJoJ+IkisQRZuBB1ZfPwlatd2j7tph4egwqGclbO2cPwlxKOVbjZ36uj/Y+ DH4JHlothDXi41ZvryUfcmaeO5mkIT3TLvq5wAa7mk8MN2imSRf2vpPcFhzigNAO T3+iPRD8U3+gQOlzxS8rx3R0qwm+60T+UHeIwkwCGuwyXGqDCy8AHZ5IBrgDaznB 29K9/aShWw/+OtlzANAtdykKzdH3vTGhKYrRrJ51G86dQ2HB2jcWgTQy7DZvqLL6 s6rkwzJW5DV4SoHBGkm/ =nDGK -----END PGP SIGNATURE----- --3jb4dx1J7KmXxJb9HW2s84SP0FvRL8nTA--