From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4900313D531; Mon, 15 Jul 2024 14:40:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721054431; cv=none; b=nSDla0dfzSEKGzgRmJFEE9tPvgdblIXUDBAywP7PYWJqhipMq6JPyCq51DIH1otGO/FAHqu5olUhTm5tZqgmgbiZcMS8Ni08hS+LOKMSeUTXp+0ShR0AN0j4Y/kjcsv882+Vlq19/qzyDzzak/Bd9sbgZMvxafWueh8o/6KzLRE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721054431; c=relaxed/simple; bh=7Qms0es8/wpmNAJDyGPB/BG2izJHXxI+19GbbNywqSQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YDauWsOiWghWEuPzMIth2tGrxAjXRWuL2k/PNnml1Fns+6W6HTXsyiMoFwSTAsTfpE9EwFtOVQxxoVTWLCEqVryBIrvTY8x0fXTZMGqcYnGQqXN4vEbunUEFu8RW//DeynHs2MZv90nHG+4hSr/eQYdZLR6+yGN4vSYLYQgwOWA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Byhrv2ZW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Byhrv2ZW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5537EC32782; Mon, 15 Jul 2024 14:40:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1721054430; bh=7Qms0es8/wpmNAJDyGPB/BG2izJHXxI+19GbbNywqSQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Byhrv2ZWmCl70GbXWN2BUbQU1Bh8a2CsMChUVlqUKoXTG4PuJY5NS9u7gkcifu/o+ 9l9/FEk/QLYu9UYkVFHM6FtjjaScIjguu9JWTijwTocJg9iQqtvlVubvpuozb4NSk+ Xp/ZfBGqJfyE5ZUKCAOymDuWTScJFYwIKCouamw+LixBykuS+vSsghzBh1yNR/A7Y9 saR1ZeXoPg40Z5ZEh45q4DkiwTezCE3iK7XXb7G3WLH1sUptRUWmaWpXLkG73NfDUC LDigeFzwRKzj0ygTf3kYm0ZJobSM1sMtptdBI9IHsA1hOmMfCnyChncf/lmfRdHXHD NC4g8tcW9r6uA== Date: Mon, 15 Jul 2024 16:40:27 +0200 From: Maxime Ripard To: Marc Gonzalez Cc: Conor Dooley , Rob Herring , Krzysztof Kozlowski , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Thomas Zimmermann , David Airlie , Daniel Vetter , Liam Girdwood , Mark Brown , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org, Arnaud Vrac , Pierre-Hugues Husson , Dmitry Baryshkov Subject: Re: [PATCH v3 1/2] dt-bindings: display: bridge: add TI TDP158 Message-ID: <20240715-stirring-purple-toad-7de58c@houat> References: <20240627-tdp158-v3-0-fb2fbc808346@freebox.fr> <20240627-tdp158-v3-1-fb2fbc808346@freebox.fr> <20240701-bug-of-great-honeydew-cfb6ef@houat> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha384; protocol="application/pgp-signature"; boundary="4m3qhydxrqaxpkry" Content-Disposition: inline In-Reply-To: --4m3qhydxrqaxpkry Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jul 04, 2024 at 07:04:41PM GMT, Marc Gonzalez wrote: > On 01/07/2024 15:50, Maxime Ripard wrote: >=20 > > The i2c register access (and the whole behaviour of the device) is > > constrained on the I2C_EN pin status, and you can't read it from the > > device, so it's also something we need to have in the DT. >=20 > I think the purpose of the I2C_EN pin might have been misunderstood. >=20 > I2C_EN is not meant to be toggled, ever, by anyone from this planet. Toggled, probably not. Connected to a GPIO and the kernel has to assert a level at boot, I've seen worse hardware design already. > I2C_EN is a layout-time setting, decided by a board manufacturer: >=20 > - If the TDP158 is fully configured once-and-for-all at layout-time, > then no I2C bus is required, and I2C_EN is pulled down forever. >=20 > - If the board manufacturer wants to keep open the possibility > to adjust some parameters at run-time, then they must connect > the device to an I2C bus, and I2C_EN is pulled up forever. How do you express both cases in your current binding? Maxime --4m3qhydxrqaxpkry Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iJUEABMJAB0WIQTkHFbLp4ejekA/qfgnX84Zoj2+dgUCZpU02wAKCRAnX84Zoj2+ dr6VAYC9M5eBCxusXRIijUkanq6xtlhkC6yWl2OTjIcDlUSVcbebs2bh+BhrDSoa s/TKenYBfA0TzhgGz76rxwe5TmG2MX7eqDw1UhEK4s514MWUphSxxPexnKdUNpWk 4mk5xdPA6g== =tNiI -----END PGP SIGNATURE----- --4m3qhydxrqaxpkry--