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=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 3E523C433DF for ; Mon, 29 Jun 2020 21:41:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20C3920656 for ; Mon, 29 Jun 2020 21:41:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593466899; bh=NgETdEp/TPGsMKNJQFJucR9ZSygTH08g48sTzqUJy8M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=M4prtf6afUuzqV2TmRRwjhkNMlEk2TohpW992kfooHrqxvhZztu5XKUDHrWL71AGH 4ysd1EamDCMxQtCFSTT4gRyx4AFu1YtnyrIeQDOIKIFDnXD0kvbtmtdJKqW0z3qNf4 HrCGDtbLhJl8NJCzZlC++91VTroMbEWdxrGHJROk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403903AbgF2Vlh (ORCPT ); Mon, 29 Jun 2020 17:41:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:60596 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726118AbgF2SkR (ORCPT ); Mon, 29 Jun 2020 14:40:17 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9501723370; Mon, 29 Jun 2020 08:41:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593420062; bh=NgETdEp/TPGsMKNJQFJucR9ZSygTH08g48sTzqUJy8M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=VfCp9hE0U1V55QP8CtGkrKq/7ClTTCkOVeDpojaZzjd7aUXx+6pITg+YyxFaYu4jr naHIJq0reLlZHSS6rTDqZoD6oWcAgnDmap4zDCam+du0CHBSo+I67WBnoXL2IzwO6f 66sWli0Vhn6A4ZyHu6XwMOh6ciaE6hDAN4crXajo= Date: Mon, 29 Jun 2020 10:40:51 +0200 From: Greg KH To: Andy Shevchenko Cc: sean.wang@mediatek.com, robh+dt@kernel.org, jslaby@suse.com, robert.jarzmik@free.fr, arnd@arndb.de, p.zabel@pengutronix.de, joel@jms.id.au, david@lechnology.com, jan.kiszka@siemens.com, heikki.krogerus@linux.intel.com, hpeter@gmail.com, vigneshr@ti.com, matthias.bgg@gmail.com, tthayer@opensource.altera.com, devicetree@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Steven Liu , Ryder Lee Subject: Re: [PATCH v4] tty: serial: don't do termios for BTIF Message-ID: <20200629084051.GA1234189@kroah.com> References: <78efa2b1e2599deff4d838b05b4054ec5ac2976a.1592595601.git.sean.wang@mediatek.com> <20200627141222.GC1901451@kroah.com> <20200629082927.GA3703480@smile.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200629082927.GA3703480@smile.fi.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 29, 2020 at 11:29:27AM +0300, Andy Shevchenko wrote: > On Sat, Jun 27, 2020 at 04:12:22PM +0200, Greg KH wrote: > > On Sat, Jun 20, 2020 at 03:59:14AM +0800, sean.wang@mediatek.com wrote: > > > From: Sean Wang > > > > > > Bluetooth Interface (BTIF) is designed dedicatedly for MediaTek SOC with > > > BT in order to be instead of the UART interface between BT module and Host > > > CPU, and not exported to user space to access. > > > > > > As the UART design, BTIF will be an APB slave and can transmit or receive > > > data by MCU access, but doesn't provide termios function like baudrate and > > > flow control setup. > > > > > > Even LCR on offset 0xC that is just a FAKELCR > > > a. If FAKELCR[7] is equaled to 1, RBR(0x00), THR(0x00), IER(0x04) > > > will not be readable/writable. > > > > > > b. If FAKELCR is equaled to 0xBF, RBR(0x00), THR(0x00), IER(0x04), > > > IIR(0x08), and LSR(0x14) will not be readable/writable. > > > > > > So adding a new capability 'UART_CAP_NTIO' for the unusual unsupported > > > case. > > > > > > The bluetooth driver would use BTIF device as a serdev. So the termios > > > still function would be called in kernelspace from ttyport_open in > > > drivers/tty/serdev/serdev-ttyprt.c. > > > > +#define UART_CAP_NTIO (1 << 18) /* UART doesn't do termios */ > > > > Naming is hard. I will never remember what "NTIO" is, how about we make > > it explicit: > > define UART_CAP_IGNORE_TERMIOS > > > > And the _CAP_ name is getting out of hand, this isn't a "capability", > > it's a "quirk for this port" but that's a battle to worry about later... > > For quirks we have a separate field in struct uart_port. Perhaps that can be used? That would be much nicer, if possible. thanks, greg k-h