From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: Sensor with 7 bit address above 0x77 Date: Mon, 27 Jun 2016 17:46:17 +0200 Message-ID: <20160627154617.GB3505@katana> References: <17002e23-eaf4-125c-9402-4def2bf13e51@sigma-star.at> <20160627121319.GA1648@katana> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="qlTNgmc+xy1dBmNv" Return-path: Received: from sauhun.de ([89.238.76.85]:41487 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751601AbcF0PqV (ORCPT ); Mon, 27 Jun 2016 11:46:21 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-i2c-owner@vger.kernel.org List-Id: linux-i2c@vger.kernel.org To: David Oberhollenzer Cc: linux-i2c@vger.kernel.org, Richard Weinberger --qlTNgmc+xy1dBmNv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > The way it is written in the spec (1111 0XX) probably caused people to > confuse it for 0xF0-0xF3 which I found in some messages on the mailing > list. Yes, it always causes confusion if the R/W bit is part of the address or not. > But that still leaves the question of where the 0xA... in the kernel docs > came from. less Documentation/i2c/ten-bit-addresses > Section 3.1.12 ends with some musings about the assignment of addresses in > "local systems". More specifically, it ends with the sentence "If it is k= nown > that the reserved address is never going to be used for its intended purp= ose, > a reserved address can be used for a slave address." >=20 > I _do_ know that there are no 10 bit addressed slaves in my application, = so > the spec allows me to use at those 4 slave address. Apparently it is not = my > device that is broken. For your specific case, I agree. For the generic case, I don't. Maybe the word "broken" is too much, though, how about calling it "risky"? That being said, as I mentioned before, I think patches adding support for using "risky" addresses in i2c-tools are acceptable, so no show-stopper here. Can you share which device uses the address 0x78? I'd like to add it to my list of "interesting I2C devices". --qlTNgmc+xy1dBmNv Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJXcUpJAAoJEBQN5MwUoCm2whwP/02f3OaIUpEmHrxWgmgODFoA h9j/x2FPGCv/sAgrTdhC0jyGNoiiHW3wvxX+qtgzwG50KLtkAUoG6moRKjTe+kPP udz84u0flpQNxalAMRJL0/6V+I6fVOSYZkgycYrYkZE2dPKIxebt6NkM+e3OORNe YCMGIOTzJWfl+P522JTHlraI5fyaKucvaPF6bftH8jboujotNYJceL2PuUcl+gdv 5UHgYabYUwfmv8HjQ5TqFDaOuofZUqJYuwdKoZgKXERYBP6Il2fE6aDBJVgsGGuO PVsg+zkPpPpFGb0LIWw2ytqFvp5UuTJ5MkypHVWiHo33Mha7Rl+I6YYJn+dC+yXg WiQnbCNj38Ttwbmcm8NUUbWo1w8luE0KveRj0/kRnsdIwtrjZ4Ybp8r2lMgIHGMa oLQfvYofTU6PeJ99siwWotExVhwpXwHV4x/CYg19rY0hSyXTz+HrXepX/CRuH16l POmBl3IIDOMpVfDmXDcmVN0Qshm1osJKOP0LwL1QM5B9gLeinI07GXAknC49RUz3 YNAO7Kf8vM6m/wosAsmi/8TSPpkOrCb+myYsfwTbATv/FZCPyal1s1R6qxOAHxzQ KXOTzrQZo6b/yjjabKzmtLfRCPAcwZXaw1oHPZATym3yyqfF/gHgqlrt/pEK82vX 19jaFOtMPuk6nFnduUmM =g/KG -----END PGP SIGNATURE----- --qlTNgmc+xy1dBmNv--