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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26049C00A8F for ; Tue, 24 Oct 2023 15:05:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229441AbjJXPFx (ORCPT ); Tue, 24 Oct 2023 11:05:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47060 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229544AbjJXPFw (ORCPT ); Tue, 24 Oct 2023 11:05:52 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8DA80122; Tue, 24 Oct 2023 08:05:50 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D05EFC433C8; Tue, 24 Oct 2023 15:05:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1698159950; bh=F93LEIRwPkxkpX2KL1Aw1knTdXl/0lgfHPPX7S8mhD8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dPzCN4kZNZYS/Q/tRDSaHBrvar62KBf4MMY+yYOVK60ZkucgZse8twWqCec42Ck+d Gvo7ebBRTAb5vW3eeeIaFl8lvUGNt9za+gToWm/ZYzGQTZGkK0Zb5AN/DqzvVDh+Iq bEZrfFY8yvLvvXUBWprjBCKEJyeKPdoJfPKJoL5g= Date: Tue, 24 Oct 2023 17:05:47 +0200 From: Greg KH To: Frank Li Cc: alexandre.belloni@bootlin.com, conor.culhane@silvaco.com, imx@lists.linux.dev, jirislaby@kernel.org, joe@perches.com, linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, miquel.raynal@bootlin.com Subject: Re: [PATCH v2 1/1] tty: i3c: add TTY over I3C master support Message-ID: <2023102442-immorally-repost-e736@gregkh> References: <20231020160027.3663772-1-Frank.Li@nxp.com> <2023102105-outfit-legroom-1633@gregkh> <2023102457-galore-uphill-4c84@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On Tue, Oct 24, 2023 at 10:31:51AM -0400, Frank Li wrote: > On Tue, Oct 24, 2023 at 11:30:33AM +0200, Greg KH wrote: > > On Mon, Oct 23, 2023 at 12:26:42PM -0400, Frank Li wrote: > > > On Sat, Oct 21, 2023 at 07:02:40PM +0200, Greg KH wrote: > > > > Note, your subject line needs to change. > > > > > > > > On Fri, Oct 20, 2023 at 12:00:27PM -0400, Frank Li wrote: > > > > > In typical embedded Linux systems, UART consoles require at least two pins, > > > > > TX and RX. In scenarios where I2C/I3C devices like sensors or PMICs are > > > > > present, we can save these two pins by using this driver. Pins is crucial > > > > > > > > "Pins are crucial" > > > > > > > > > resources, especially in small chip packages. > > > > > > > > > > This introduces support for using the I3C bus to transfer console tty data, > > > > > effectively replacing the need for dedicated UART pins. This not only > > > > > conserves valuable pin resources but also facilitates testing of I3C's > > > > > advanced features, including early termination, in-band interrupt (IBI) > > > > > support, and the creation of more complex data patterns. Additionally, > > > > > it aids in identifying and addressing issues within the I3C controller > > > > > driver. > > > > > > > > But where is the serial data ending up at? Not a normal uart, what is > > > > on the other end? And do line settings mean anything here? > > > > > > Currently, it use slave i3c code. > > > https://lore.kernel.org/imx/20231018215809.3477437-1-Frank.Li@nxp.com/T/#t > > > > > > idealy build an i3c->usb dongle to bride it to usb acm. > > > > So no one has built such a thing yet to determine if any of this works? > > It is easy to proof concept by I3C slave code and USB gadget ACM, then pipe > two tty (ttyACM0 and ttySI3C0 together). So you have not actually tested this? why write a driver that no one is using? > Of we also can implement a USB to I3C class standard, base on this, reuse > this tty driver at host side. Is there a USB I3C standard? I see i3c descriptors assigned by the USB-IF, but haven't dug to see if there's more than that anywhere... thanks, greg k-h