From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zeus03.de (zeus03.de [194.117.254.33]) (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 3DF7B187333 for ; Fri, 14 Jun 2024 08:12:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.117.254.33 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718352779; cv=none; b=FA8pwZZUCKzUYRG6ES2FX1dmrAURo9gJmZRJhqpfOt2ClpntrL+JsxX7dSYeH9Y9lpBcstaTVBGQNFto6o+R4GNF2Hjk7QwXj8ze63cOtCq7CKqsuVJbeToRU5RXz0fEitGEQUlhzWZEAAmZ49uFhejAL+N9jBizfTKlEUzwXzA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718352779; c=relaxed/simple; bh=BVEwSEZWW70n3zK43WnEFFNovrnrFP6C9VNMi4Zg6mM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=acCjwo0BDrFcxCBym1gWDGhxYF3ACJa9oU5K31z3nRiBiXEfBXIoUCu3i+0dZrJxM4SXnRomuPYegLFNZGbGiSAegaozSAPQLOJTStZQIDNFMSLohZTnwiCisOGmrdutarl02OFrs2AGgYeKnY5xFdz2jJ27OwAd0XRA7ObZn3s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com; spf=pass smtp.mailfrom=sang-engineering.com; dkim=pass (2048-bit key) header.d=sang-engineering.com header.i=@sang-engineering.com header.b=PX3Vsfla; arc=none smtp.client-ip=194.117.254.33 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sang-engineering.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sang-engineering.com header.i=@sang-engineering.com header.b="PX3Vsfla" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= sang-engineering.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-transfer-encoding; s=k1; bh=x+OirvJmm2z8OY7TiPcj0ELlgpYDPQ+Seo1lKvUO+VI=; b=PX3Vsf laINXXGy3e3zub0bL77RqjsZYszfE483pUzNdyKQdEEvpy6I9/Mtr6t/pVGqWb/R dvaPM3v2WhJ9KefQ/ritD72/2c4eubbeE+PKAF93EoYbgnOzOLrD51nFjMIvhw5r b5CVo2SsGSagW+NEgkJa9tOliyu3sPBf7EY55Oe5Qxdr/N8I0YNRp5yBHXV3VuCe bE6aKjND8v0eLk7qyS0fI5IVAvkkpTjnmQ9kBfKjCltaGe5yLnbPL+aPNXrsOQW4 vajav7vusIciE4k2MuWTSjaOBGOezzRqEAz9Rp7Kqg/LIUF9vqHGmznNAZds7uiG TfrbPUzL/Fi2yGNQ== Received: (qmail 1438219 invoked from network); 14 Jun 2024 10:12:51 +0200 Received: by mail.zeus03.de with ESMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 14 Jun 2024 10:12:51 +0200 X-UD-Smtp-Session: l3s3148p1@wNCFLtUaNIIgAwDPXzjQABqqX1QYyOSW From: Wolfram Sang To: linux-i2c@vger.kernel.org Cc: Easwar Hariharan , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Andi Shyti , Wolfram Sang Subject: [PATCH v3 6/6] docs: i2c: summary: be clearer with 'controller/target' and 'adapter/client' pairs Date: Fri, 14 Jun 2024 10:12:44 +0200 Message-ID: <20240614081239.7128-14-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240614081239.7128-8-wsa+renesas@sang-engineering.com> References: <20240614081239.7128-8-wsa+renesas@sang-engineering.com> Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This not only includes rewording, but also where to put which emphasis on terms in this document. Signed-off-by: Wolfram Sang --- Documentation/i2c/summary.rst | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/Documentation/i2c/summary.rst b/Documentation/i2c/summary.rst index ff8bda32b9c3..90f46f1504fe 100644 --- a/Documentation/i2c/summary.rst +++ b/Documentation/i2c/summary.rst @@ -31,9 +31,7 @@ implement all the common SMBus protocol semantics or messages. Terminology =========== -The I2C bus connects one or more *controller* chips and one or more *target* -chips. - +The I2C bus connects one or more controller chips and one or more target chips. .. kernel-figure:: i2c_bus.svg :alt: Simple I2C bus with one controller and 3 targets @@ -41,16 +39,16 @@ chips. Simple I2C bus A **controller** chip is a node that starts communications with targets. In the -Linux kernel implementation it is called an **adapter** or bus. Adapter -drivers are in the ``drivers/i2c/busses/`` subdirectory. +Linux kernel implementation it is called an "adapter" or "bus". Controller +drivers are usually in the ``drivers/i2c/busses/`` subdirectory. -An **algorithm** contains general code that can be used to implement a -whole class of I2C adapters. Each specific adapter driver either depends on -an algorithm driver in the ``drivers/i2c/algos/`` subdirectory, or includes -its own implementation. +An **algorithm** contains general code that can be used to implement a whole +class of I2C controllers. Each specific controller driver either depends on an +algorithm driver in the ``drivers/i2c/algos/`` subdirectory, or includes its +own implementation. A **target** chip is a node that responds to communications when addressed by a -controller. In the Linux kernel implementation it is called a **client**. While +controller. In the Linux kernel implementation it is called a "client". While targets are usually separate external chips, Linux can also act as a target (needs hardware support) and respond to another controller on the bus. This is then called a **local target**. In contrast, an external chip is called a @@ -60,9 +58,18 @@ Target drivers are kept in a directory specific to the feature they provide, for example ``drivers/gpio/`` for GPIO expanders and ``drivers/media/i2c/`` for video-related chips. -For the example configuration in figure, you will need a driver for your -I2C adapter, and drivers for your I2C devices (usually one driver for each -device). +For the example configuration in the figure above, you will need one driver for +the I2C controller, and drivers for your I2C targets. Usually one driver for +each target. + +Synonyms +-------- + +As mentioned above, the Linux I2C implementation historically uses the terms +"adapter" for controller and "client" for target. A number of data structures +have these synonyms in their name. So, to discuss implementation details, it +might be easier to use these terms. If speaking about I2C in general, the +official terminology is preferred. Outdated terminology -------------------- -- 2.43.0