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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=unavailable 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 20824C43613 for ; Mon, 24 Jun 2019 19:55:07 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E12B720645 for ; Mon, 24 Jun 2019 19:55:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="AGDENTdM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E12B720645 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Date:To:From:Subject:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=bGQqtScigLriJ0hsWo8YyqhLLFUtvng0zwzgZCzs5pY=; b=AGDENTdMFFcLpm gCg6hqMr7PZHsWEL2zbDZpTGWPWddaKjehgAmKHlwvx77abtohYngs4nybysRN27BlkXlhrsGJnof uUEsRzcaX2l6zRwxUBovr6WdUvjH7JP/6dPrhO7hrH7e4syQEbBn+G3UPK5aEV4OXiEdMANzOWYkB uqM7B6i6qrfaDVKk/YiRrAxAkSHLL4zbqjzJWYUxS4V3AlRLBMXfJPzGq57koJM1TnOYi7/mYLSdJ m+5CiT5JwsdHhIf7it/kF7l4Td+f4BDcrkPrGJOSv/7CVepI5J5JP1cyeUoaHuFPN59Lt2enaydHk aUMZldeJ4dMi6WCYbpbg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hfV3H-0006s0-MK; Mon, 24 Jun 2019 19:54:55 +0000 Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hfV3E-0006rK-L1 for linux-arm-kernel@lists.infradead.org; Mon, 24 Jun 2019 19:54:54 +0000 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A453D3078AB7; Mon, 24 Jun 2019 19:54:38 +0000 (UTC) Received: from ovpn-112-53.rdu2.redhat.com (ovpn-112-53.rdu2.redhat.com [10.10.112.53]) by smtp.corp.redhat.com (Postfix) with ESMTP id BFA0D5D70D; Mon, 24 Jun 2019 19:54:31 +0000 (UTC) Message-ID: Subject: Re: WWAN Controller Framework (was IPA [PATCH v2 00/17]) From: Dan Williams To: Alex Elder , davem@davemloft.net, arnd@arndb.de, bjorn.andersson@linaro.org, ilias.apalodimas@linaro.org Date: Mon, 24 Jun 2019 14:54:30 -0500 In-Reply-To: <23ff4cce-1fee-98ab-3608-1fd09c2d97f1@linaro.org> References: <20190531035348.7194-1-elder@linaro.org> <23ff4cce-1fee-98ab-3608-1fd09c2d97f1@linaro.org> User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Mon, 24 Jun 2019 19:54:51 +0000 (UTC) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190624_125452_732278_26CE2F6C X-CRM114-Status: GOOD ( 21.55 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, syadagir@codeaurora.org, ejcaruso@google.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, evgreen@chromium.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, subashab@codeaurora.org, linux-soc@vger.kernel.org, abhishek.esse@gmail.com, cpratapa@codeaurora.org, benchan@google.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, 2019-06-24 at 11:30 -0500, Alex Elder wrote: > OK I want to try to organize a little more concisely some of the > discussion on this, because there is a very large amount of volume > to date and I think we need to try to narrow the focus back down > again. > > I'm going to use a few terms here. Some of these I really don't > like, but I want to be unambiguous *and* (at least for now) I want > to avoid the very overloaded term "device". > > I have lots more to say, but let's start with a top-level picture, > to make sure we're all on the same page. > > WWAN Communication > Channel (Physical) > | ------------------------ > ------------ v | :+ Control | \ > > |-----------| :+ Data | | > > AP | | WWAN unit :+ Voice | > Functions > > |===========| :+ GPS | | > ------------ ^ | :+ ... | / > | ------------------------- > Multiplexed WWAN > Communication > Channel (Physical) > > - The *AP* is the main CPU complex that's running Linux on one or > more CPU cores. > - A *WWAN unit* is an entity that shares one or more physical > *WWAN communication channels* with the AP. You could just say "WWAN modem" here. > - A *WWAN communication channel* is a bidirectional means of > carrying data between the AP and WWAN unit. > - A WWAN communication channel carries data using a *WWAN protocol*. > - A WWAN unit implements one or more *WWAN functions*, such as > 5G data, LTE voice, GPS, and so on. Go more generic here. Not just 5G data but any WWAN IP-based data (GPRS, EDGE, CDMA, UMTS, EVDO, LTE, 5G, etc). And not just LTE voice but any voice data; plenty of devices don't support LTE but still have "WWAN logical communication channels" > - A WWAN unit shall implement a *WWAN control function*, used to > manage the use of other WWAN functions, as well as the WWAN unit > itself. > - The AP communicates with a WWAN function using a WWAN protocol. > - A WWAN physical channel can be *multiplexed*, in which case it > carries the data for one or more *WWAN logical channels*. It's unclear to me what "physical" means here. USB Interface or Endpoint or PCI Function or SMD channel? Or kernel TTY device? For example on Qualcomm-based USB dongles a given USB Interface's Endpoint represents a QMAP "IP data" channel which itself could be multiplexed into separate "IP data" channels. Or that USB Endpoint(s) could be exposed as a TTY which itself can be MUX-ed dynamically using GSM 07.10. To me "physical" usually means the bus type (PCI, USB, SMD, whatever). A Linux hardware driver (IPA, qmi_wwan, option, sierra, etc) binds to that physical entity using hardware IDs (USB or PCI VID/PID, devicetree properties) and exposes some "WWAN logical communication channels". Those logical channels might be multiplexed and another driver (rmnet) could handle exposing the de-muxed logical channels that the muxed logical channel carries. > - A multiplexed WWAN communication channel uses a *WWAN wultiplexing > protocol*, which is used to separate independent data streams > carrying other WWAN protocols. > - A WWAN logical channel carries a bidirectional stream of WWAN > protocol data between an entity on the AP and a WWAN function. It *usually* is bidirectional. For example some GPS logical communication channels just start spitting out NMEA when you give the control function a command. The NMEA ports themselves don't accept any input. > Does that adequately represent a very high-level picture of what > we're trying to manage? Yes, pretty well. Thanks for trying to specify it all. > And if I understand it right, the purpose of the generic framework > being discussed is to define a common mechanism for managing (i.e., > discovering, creating, destroying, querying, configuring, enabling, > disabling, etc.) WWAN units and the functions they implement, along > with the communication and logical channels used to communicate with > them. Yes. Dan > Comments? > > -Alex _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel