From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D70FBC18E5B for ; Tue, 10 Mar 2020 12:29:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AAF1F24655 for ; Tue, 10 Mar 2020 12:29:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726423AbgCJM3g (ORCPT ); Tue, 10 Mar 2020 08:29:36 -0400 Received: from sauhun.de ([88.99.104.3]:48178 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726331AbgCJM3g (ORCPT ); Tue, 10 Mar 2020 08:29:36 -0400 Received: from localhost (p54B33196.dip0.t-ipconnect.de [84.179.49.150]) by pokefinder.org (Postfix) with ESMTPSA id CED972C1EB6; Tue, 10 Mar 2020 13:29:34 +0100 (CET) Date: Tue, 10 Mar 2020 13:29:34 +0100 From: Wolfram Sang To: Rishi Gupta Cc: jikos@kernel.org, benjamin.tissoires@redhat.com, wsa+renesas@sang-engineering.com, gregkh@linuxfoundation.org, linux-i2c@vger.kernel.org, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] HID: mcp2221: add usb to i2c-smbus host bridge Message-ID: <20200310122934.GA13896@ninjato> References: <1580185137-11255-1-git-send-email-gupt21@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="nFreZHaLTZJo0R7j" Content-Disposition: inline In-Reply-To: <1580185137-11255-1-git-send-email-gupt21@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --nFreZHaLTZJo0R7j Content-Type: text/plain; charset=us-ascii Content-Disposition: inline > + if (num == 1) { > + if (msgs->flags & I2C_M_RD) { > + ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA, > + 0, 0, NULL); > + } else { > + ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1); > + } > + if (ret) > + goto exit; > + ret = num; > + } else if (num == 2) { > + /* Ex transaction; send reg address and read its contents */ > + if (msgs[0].addr == msgs[1].addr && > + !(msgs[0].flags & I2C_M_RD) && > + (msgs[1].flags & I2C_M_RD)) { > + > + ret = mcp_i2c_write(mcp, &msgs[0], > + MCP2221_I2C_WR_NO_STOP, 0); > + if (ret) > + goto exit; > + > + ret = mcp_i2c_smbus_read(mcp, &msgs[1], > + MCP2221_I2C_RD_RPT_START, > + 0, 0, NULL); > + if (ret) > + goto exit; > + ret = num; > + } else { > + dev_err(&adapter->dev, > + "unsupported multi-msg i2c transaction\n"); > + ret = -EOPNOTSUPP; > + } > + } else { > + dev_err(&adapter->dev, > + "unsupported multi-msg i2c transaction\n"); > + ret = -EOPNOTSUPP; > + } Have a look at struct i2c_adapter_quirks and especially the flags to let the I2C core do the sanity checks from here. --nFreZHaLTZJo0R7j Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAl5niCoACgkQFA3kzBSg Kbbcbw/7BH9KSGZnx60OjlH4kqubSsU/7webUKwIWx40VdSbxBmccq49gipAxmP5 k1fMwsW0uCKcslR/iJ7R88cM8BLP1led1JCbGsbZ2AYMs1liYrcz/np7xxVG5NqZ 33L+D2OyXovtD+9gQudVIF593s0BipaL3FBDvmSayBs/qZldA1OKrt5xKshu6Gu3 twzjtixSLjQnqxhydQ0rva5i0Wccd5X++VTthF1zCfydoN9Yuj+wfu+surk2y9fP Nou7eizASM27B5yl4T4VJgzrAZZmq2Mq3HeY1/fZ5ic9rIATj819xGOw0NqBpgsr MgZiUh0shBJenx4gXYD+oZxUxaqGQFb12V88vfWnIw+0l4n5L54sfVhTXmAZE2zC yMZ5oBLvrQfO6dDGPz5PKYqN1hS0YM+pGaGBi3Fx8mna3QvdbZFe4bLNNvA0wcsX vg4UgMvfavZAAjpCQtkY8p7ew1dFyOs5eLinYsnVuF9T1KcjOFWlx90/+GOMYeoZ TzxD2TFDjc8/7Jp60r+IkDgpLwH8/YxsBoy9ESzSi7MBzQLuSw7hju5OATmQ/Sld oGMy9aUtIEVW2Y/t6P2XbMeFOBGwc0zXO1pWVKS6Pqj1yqYf7QcHWcjwd2CyAyif Dr9fv+gGmqZ+hEED4tRPQMuzbXvVbax3IlNOOI4rYT8c3LuKUx8= =rvj5 -----END PGP SIGNATURE----- --nFreZHaLTZJo0R7j--