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=-0.7 required=3.0 tests=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 9FAE2C433DF for ; Wed, 8 Jul 2020 14:58:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 812D020720 for ; Wed, 8 Jul 2020 14:58:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729985AbgGHO6T (ORCPT ); Wed, 8 Jul 2020 10:58:19 -0400 Received: from mga01.intel.com ([192.55.52.88]:54394 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729206AbgGHO6R (ORCPT ); Wed, 8 Jul 2020 10:58:17 -0400 IronPort-SDR: ItNlxMO4N6NFzkLUzKIzJTKj+/rPBNB2N2fEThqdQ4ZfnFaBhLekkzMDGpnaA9WEFYO2K1NCUx 4jZkNgkDLoOA== X-IronPort-AV: E=McAfee;i="6000,8403,9676"; a="165921741" X-IronPort-AV: E=Sophos;i="5.75,327,1589266800"; d="scan'208";a="165921741" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Jul 2020 07:58:17 -0700 IronPort-SDR: id16Q0uJtbOwrtqSPDTWmtvVUzlkhQZprKMISQjsDMxp0dUVrEX7FPeAtyajoU+9ZFd/GiqnvE KR9Em0UU8CYQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,327,1589266800"; d="scan'208";a="427862028" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga004.jf.intel.com with ESMTP; 08 Jul 2020 07:58:13 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1jtBWY-000gwo-3z; Wed, 08 Jul 2020 17:58:14 +0300 Date: Wed, 8 Jul 2020 17:58:14 +0300 From: Andy Shevchenko To: sean.wang@mediatek.com Cc: gregkh@linuxfoundation.org, jslaby@suse.com, mika.westerberg@linux.intel.com, sr@denx.de, arnd@arndb.de, matthias.bgg@gmail.com, tthayer@opensource.altera.com, 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 v5] tty: serial: don't do termios for BTIF Message-ID: <20200708145814.GN3703480@smile.fi.intel.com> References: <7c67171728cdcc4ccc10adfaea1a14bfbcf8375a.1594163304.git.sean.wang@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7c67171728cdcc4ccc10adfaea1a14bfbcf8375a.1594163304.git.sean.wang@mediatek.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 08, 2020 at 07:11:22AM +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. ... > up->port.quirks |= skip_txen_test ? UPQ_NO_TXEN_TEST : 0; > + > + if (up->port.type == PORT_MTK_BTIF) > + up->port.quirks |= UPQ_IGNORE_TERMIOS; I don't like to see this in core. Can we have this inside 8250_port.c? Something like extending struct serial8250_config to carry quirks and assign them when you add a port or start it (wherever it's appropriated)? -- With Best Regards, Andy Shevchenko