Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752872Ab3JKElY (ORCPT ); Fri, 11 Oct 2013 00:41:24 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:50185 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751590Ab3JKElW (ORCPT ); Fri, 11 Oct 2013 00:41:22 -0400 Message-ID: <5257815F.5070803@ti.com> Date: Fri, 11 Oct 2013 07:41:03 +0300 From: Tomi Valkeinen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Lars-Peter Clausen , "Dr. H. Nikolaus Schaller" CC: Marek Belisko , , , , Subject: Re: [PATCH] omapdss: Add new panel driver for Topolly td028ttec1 LCD. References: <1381352915-17219-1-git-send-email-marek@goldelico.com> <525662F5.3090600@ti.com> <7FAC77D4-5E1E-4B11-B067-3A8233C69240@goldelico.com> <52568B40.4040802@ti.com> <04AC7291-38E4-421B-979C-BF03D52E94BD@goldelico.com> <525699EF.6090803@ti.com> <52569CE8.5070201@metafoo.de> <5256F8DF.2020801@metafoo.de> In-Reply-To: <5256F8DF.2020801@metafoo.de> X-Enigmail-Version: 1.5.2 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="9x9VSX3e6dLJt6dBCVpNX6WPeBqmL5WEh" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2653 Lines: 68 --9x9VSX3e6dLJt6dBCVpNX6WPeBqmL5WEh Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 10/10/13 21:58, Lars-Peter Clausen wrote: > According to the datasheet the the panel as a dedicated dout pin. Maybe= > you did not connect it in your design, which means you won't be able to= > read any data from the panel at all. I don't see a dedicated dout in the datasheet... http://dl.wolfgang-draxinger.net/openmoko/doc/TD028TTEC1.pdf > Also your custom bitbang code looks a bit strange: >=20 > gpio_set_value(data->dout_gpio, 1); > if (gpio_get_value(data->din_gpio) =3D=3D 0) > return 1; >=20 > You set the state on the dout pin and then read the din pin, if both do= > not match you abort with an error. This suggest that, for whatever > reason, you feed the dout pin back into the din pin in your design. Btw= =2E > this is also the only place where din is used in your driver. Yes, he said the single "Serial interface data input/output" pin is connected to both din and dout on the SoC. I guess the purpose of that gpio_get_value() is to ensure that the panel is not pulling the line when the SoC is writing to it. Not that I really understand how that can work, but I'm not a HW guy =3D). Tomi --9x9VSX3e6dLJt6dBCVpNX6WPeBqmL5WEh Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJSV4FfAAoJEPo9qoy8lh71FqUP/RWOBdaCtbA8frs7yA4340St i8H7RNlW4F8BEUZEylYYoT0h6KYy8lDcSGcfNJSQM0D7z/1kcyBVXZ8oUXIaJh6w fXCYSmrD8v7d3DAxNe4pr+GmpMo+i/exxJterDaFBsLJJ69ubwAf+s358C9NSdvo Iv2m3rNXr0OXWDooqpvyTNSxO9EKBBunr7hG8LE28OBZkKJ3wKw1T9ivUvu55cXp ZKxxq4sQIHJq0I4cw3AzSMd52u0JQ3nqaQQ6pyCl8LWZg9lq11Bp+SA1jhBd/pak 2SpsDGEHE2Z/SG5bfXpyVXedQpMgAHkDhCe3TNCpkR8IR0dt2fOAW3jnmULeX2gR 49MYFwifQvwECE5Eu7AULMoM+Hg665piZJ2s+g9tA2MLElW+cFTwTTvMqYDJrCXR 7GK+GKzpqMB105PNB/VAkooiwBWpNmPzQEPgtdwV+HvIVGTWOc9JVpE2n+JgDLxu pmi67rVGRFT5OO06smfSntd/qnM+CL7IRR8lgVxQk7x75sTcXjVRYAOB5fq6dgzk bdN0wa03WA2M9KsdEWzEig/LvZOEuiZsSDDuizGH1/EC0w1n/1orKAkmvBK6gu9C 4h0KtalVI4BnunsFu1ITOwl6S9n+QZnib1He/pabgkCLMys+5dIFS4Hslb/aV61g wI6Vz8UEGXzYs+gYu10x =Wmnq -----END PGP SIGNATURE----- --9x9VSX3e6dLJt6dBCVpNX6WPeBqmL5WEh-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/