From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761824AbcINMIR convert rfc822-to-8bit (ORCPT ); Wed, 14 Sep 2016 08:08:17 -0400 Received: from mout.kundenserver.de ([217.72.192.74]:63061 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756302AbcINMIO (ORCPT ); Wed, 14 Sep 2016 08:08:14 -0400 From: Arnd Bergmann To: linux-arm-kernel@lists.infradead.org Cc: "zhichang.yuan" , zhichang , lorenzo.pieralisi@arm.com, gabriele.paoloni@huawei.com, minyard@acm.org, benh@kernel.crashing.org, john.garry@huawei.com, liviu.dudau@arm.com, linuxarm@huawei.com, linux-kernel@vger.kernel.org, zourongrong@gmail.com Subject: Re: [PATCH V2 3/4] ARM64 LPC: support serial based on low-pin-count Date: Wed, 14 Sep 2016 14:07:22 +0200 Message-ID: <13406676.rztgqQLiFa@wuerfel> User-Agent: KMail/5.1.3 (Linux/4.4.0-34-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: <57D93921.50303@hisilicon.com> References: <1473255233-154297-1-git-send-email-yuanzhichang@hisilicon.com> <2531252.L41vzyMSKX@wuerfel> <57D93921.50303@hisilicon.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K0:qfDi57VMRKaV6kJ5wps8rvM7DM8A0tCvcpvDOuV1hp8jW+Lilxs hcE9eSTu+BLpEupApBzTEm598yZs7ZTfz4tL36meG7Wj91HTX72iazktxJEeXT9HipsNE5B PeddA9OnJYBI5Runhr1bCckKkOfTYGVyQpf+OMwDXu279Fo14W1GuIvkguA9+c4AYV5g5tj ox5F48GsA5Q+jzsRTh7Nw== X-UI-Out-Filterresults: notjunk:1;V01:K0:frvvoNog0c8=:9ZLAzn0+/7hacovhzgwicd oj41kerFR7Hjkem3wO3WKjECDHS1oysnfA2b+4QyQa7Fqe1686v+48RFR1u5y9BJCblCd4Z6a Y+g5qaQg5H1ZnydYrO6g4MIuSTIlevJmAbrx//wTD4/tgqM/jX6eQOKDzoszVMZTH3MZQZR7h 8ulIsTgoreozKSWqNKAa2JDBOpwmWfCcJSkr5WctKcm/oerQL71bGTxCkEUYdWFuDukykLup4 htjJocxIaLFz7La1n4aX4PTX5qYu+M/0zxjbUGHEqadpg0rFisW/8ReQuacNoB9XJ9Q6GIYhP XfqkDUFI50S1g967uzvmu6j4vT8QHUBs4yTVhlUDGG+EmSS/1KxauSj8gHd/YJyXb10AosDZH Z+QZL/t7tNiJ9bKDFKNW318EeEuLHzWf0RMD6kNTCW+ugYEmSpcdtNsytBHkPNmvFgZcaxY+I 5bP6OaXAGrZNGdYUGMen8nYd3L+kdPrWzK/dm58/IIxcrylNLuY7FA56D528sZxIOtVLA64hA GoB+tor6KF/sZubcExxe9Fa78bW0V3ofj5CJLSP3bLGBUY9w3r6VkPSYouZgNcRiNT0gqYc5R nXfPP1HK96eXaQuXhoVWLN2M6xQMyJlKWPZ2FGUky+XOUVgtVsb3Ff+LQFQCegi752eeD6fz5 XSonNmDS0Wv/DG74ZjBot1jRoxfwx2uRd32X9RgAHoENgyHhdz5+QbRZY14o5aRXO2NfCCQHY jqbZsadaOzzF9axy0SR9X/NU5YjWYcQfIA0BHN3NjWVdcSrxBYULDLsBxas3K/Jah0/OlZB1J zNk8kpvdSfFPaUaEdNx5CFbFkEIqcJ7WCwZfWfZHboquyoZHHQi2yAEsXMvgRFpc4b4l9ao8I FtJaVVX1x53g/eRS9eezC8hD43z37nDkUt43swMEI= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday, September 14, 2016 7:48:49 PM CEST zhichang.yuan wrote: > On 2016/9/8 17:58, Arnd Bergmann wrote: > > On Thursday, September 8, 2016 5:51:25 PM CEST zhichang wrote: > >> On 2016年09月07日 22:50, Arnd Bergmann wrote: > >>> On Wednesday, September 7, 2016 9:33:52 PM CEST Zhichang Yuan wrote: > >>>> From: "zhichang.yuan" > >>>> > >>>> On Hip06 platform, a 16550 compatible UART is connected to low-pin-count and > >>>> controlled through the LPC I/O cycles. This patch drives the UART port with > >>>> the specific serial in/out function pair based on the indirect-IO mechanism > >>>> introduced by Hip06 LPC driver. > >>>> > >>>> Signed-off-by: zhichang.yuan > >>> > >>> Any reason this cannot just use the regular drivers/tty/serial/8250/8250_of.c > >>> driver? > >> I think two reasons for that: > >> 1. 8250_of.c is only for devicetree, but we need to support ACPI device too; > > > > ACPI has its own way of describing serial ports, use that instead. > Could you give me some info about ACPI serial ports? > I found there is _CRS specific for serial, but it seems no serial driver use that. drivers/tty/serial/8250/8250_dw.c is a driver that uses ACPI matching, and possibly drivers/tty/serial/8250/8250_pnp.c could work as well. Arnd