From patchwork Wed Jan 29 15:19:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Luca Ceresoli X-Patchwork-Id: 1230952 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-i2c-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=lucaceresoli.net Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4876cG4HhCz9sRR for ; Thu, 30 Jan 2020 02:20:14 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726801AbgA2PUN (ORCPT ); Wed, 29 Jan 2020 10:20:13 -0500 Received: from hostingweb31-40.netsons.net ([89.40.174.40]:47902 "EHLO hostingweb31-40.netsons.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726701AbgA2PUM (ORCPT ); Wed, 29 Jan 2020 10:20:12 -0500 Received: from [109.168.11.45] (port=33588 helo=pc-ceresoli.dev.aim) by hostingweb31.netsons.net with esmtpa (Exim 4.92) (envelope-from ) id 1iwp8U-004sQJ-2b; Wed, 29 Jan 2020 16:20:10 +0100 From: Luca Ceresoli To: linux-i2c@vger.kernel.org, linux-doc@vger.kernel.org Cc: Luca Ceresoli , Wolfram Sang , Jean Delvare , Peter Rosin , linux-kernel@vger.kernel.org Subject: [PATCH v3 02/28] docs: i2c: summary: extend introduction Date: Wed, 29 Jan 2020 16:19:27 +0100 Message-Id: <20200129151953.31582-3-luca@lucaceresoli.net> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200129151953.31582-1-luca@lucaceresoli.net> References: <20200129151953.31582-1-luca@lucaceresoli.net> MIME-Version: 1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - hostingweb31.netsons.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lucaceresoli.net X-Get-Message-Sender-Via: hostingweb31.netsons.net: authenticated_id: luca+lucaceresoli.net/only user confirmed/virtual account not confirmed X-Authenticated-Sender: hostingweb31.netsons.net: luca@lucaceresoli.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org - state the "official" name (I²C, not I2C, according to the spec) at the beginning but keep using the more practical I2C elsewhere - mention some known different names - add link to the specification document Signed-off-by: Luca Ceresoli Reviewed-by: Jean Delvare --- Changes in v2: - clarify sentence (Jean Delvare) --- Documentation/i2c/summary.rst | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/Documentation/i2c/summary.rst b/Documentation/i2c/summary.rst index 3a24eac17375..dbab737d5075 100644 --- a/Documentation/i2c/summary.rst +++ b/Documentation/i2c/summary.rst @@ -2,12 +2,18 @@ I2C and SMBus ============= -I2C (pronounce: I squared C) is a protocol developed by Philips. It is a -slow two-wire protocol (variable speed, up to 400 kHz), with a high speed -extension (3.4 MHz). It provides an inexpensive bus for connecting many -types of devices with infrequent or low bandwidth communications needs. -I2C is widely used with embedded systems. Some systems use variants that -don't meet branding requirements, and so are not advertised as being I2C. +I²C (pronounce: I squared C and written I2C in the kernel documentation) is +a protocol developed by Philips. It is a slow two-wire protocol (variable +speed, up to 400 kHz), with a high speed extension (3.4 MHz). It provides +an inexpensive bus for connecting many types of devices with infrequent or +low bandwidth communications needs. I2C is widely used with embedded +systems. Some systems use variants that don't meet branding requirements, +and so are not advertised as being I2C but come under different names, +e.g. TWI (Two Wire Interface), IIC. + +The official I2C specification is the `"I2C-bus specification and user +manual" (UM10204) `_ +published by NXP Semiconductors. SMBus (System Management Bus) is based on the I2C protocol, and is mostly a subset of I2C protocols and signaling. Many I2C devices will work on an