From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sauhun.de ([88.99.104.3]:48716 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932129AbeDWUgR (ORCPT ); Mon, 23 Apr 2018 16:36:17 -0400 Date: Mon, 23 Apr 2018 22:36:16 +0200 From: Wolfram Sang Subject: Re: [PATCH v3 02/11] media: ov772x: allow i2c controllers without I2C_FUNC_PROTOCOL_MANGLING Message-ID: <20180423203615.2ntymbibkgw2aiks@ninjato> References: <1524412577-14419-1-git-send-email-akinobu.mita@gmail.com> <3172940.h9isB0x1K9@avalon> <20180423201121.cgcg6isobtku7swy@ninjato> <6809346.dy34v3ukH6@avalon> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="i6xzbq3fz2aj6t4m" Content-Disposition: inline In-Reply-To: <6809346.dy34v3ukH6@avalon> Sender: devicetree-owner@vger.kernel.org To: Laurent Pinchart Cc: Akinobu Mita , linux-media@vger.kernel.org, "open list:OPEN FIRMWARE AND..." , Jacopo Mondi , Hans Verkuil , Sakari Ailus , Mauro Carvalho Chehab List-ID: --i6xzbq3fz2aj6t4m Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > SCCB helpers would work too. It would be easy to just move the functions= =20 > defined in this patch to helpers and be done with it. However, there are = I2C=20 > adapters that have native SCCB support, so to take advantage of that feat= ure=20 Ah, didn't notice that so far. Can't find it in drivers/i2c/busses. Where are those? > we need to forward native SCCB calls all the way down the stack in that c= ase.=20 And how is it done currently? > That's why I thought an implementation in the I2C subsystem would be bett= er.=20 > Furthermore, as SCCB is really a slightly mangled version of I2C, I think= the=20 > I2C subsystem would be a natural location for the implementation. It shou= ldn't=20 Can be argued. But it can also be argues that it sits on top of I2C and doesn't need to live in i2c-folders itself (like PMBus). The implementation given in this patch looks a bit like the latter. However, this is not the main question currently. > be too much work, it's just a matter of deciding what the call stacks sho= uld=20 > be for the native vs. emulated cases. I don't like it. We shouldn't use SMBus calls for SCCB because SMBus will very likely never support it. Or do you know of such a case? I think I really want sccb helpers. So, people immediately see that SCCB is used and not SMBus or I2C. And there, we can handle native support vs. I2C-SCCB-emulation. And maybe SMBus-SCCB emulation but I doubt we will ever need it. --i6xzbq3fz2aj6t4m Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAlreQ78ACgkQFA3kzBSg KbaTmg//aVCYkT8V6H8qX3Y18egbGxlHQGQ+pkPhhMMIZisCwhb5SjS7ptks1MgQ JkKh1kuf9J1Cb/C+dQfuMOA74r5BqaPWpzhcH0iFeabY8Lq3oh+5gaqlC1ILoL8b Ppdr7S7yb/eojx/4j8vsy6WfcQxyyGSYMleL9ukVUU7dcQ9O8Tu4+MxgaOFXK22m gngbZGL8o+YUegobdPj7ctC58cuYozrZXcQmy9uknmuHE9+KvbLdulTwytHgv4iZ nxRA1StT1yeXPzTsm8H0EdFfm9gEn8Z88LvSvC4gLt5Nsro3KmdyPQBhJMgLOpL+ k/ICuf+ZKZFFspud8dh7sMwhIQ/4sf4hSJizVyZVRWdz9h9sfWxbcjJuuEqZZK+D K1+WjflN61bswm3I7V5G2dn/cboJDed7pFxY2RIlJML9spYKw3RBAMu2GeDg7fcV ZAQJ7FcgzgXi1uDLHhnhQStKfJygd+tUfGOVCdsyiK9Mf8J0T7Y8tKwumj94uQMF 955hXinZlCewUdqv98EB4M0EwHosE0BhQRJ8RCE5yndkzoJjyv+Cz2t62NgG56/Q abFffEvi6yV0Ox2cWRPbUBbYUueE/DtGcOM1T8y4zMcjcZLMGTUjjsJa88xtYJ9t MM+tIYpPJOr3SdKpqKXjOlf+cXA3OH2xt+LHW+NAQg7zqbdhAJQ= =lcnH -----END PGP SIGNATURE----- --i6xzbq3fz2aj6t4m--