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=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 E4384C43387 for ; Thu, 3 Jan 2019 08:07:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BAF7B20883 for ; Thu, 3 Jan 2019 08:07:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729747AbfACIHU (ORCPT ); Thu, 3 Jan 2019 03:07:20 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:33972 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726112AbfACIHU (ORCPT ); Thu, 3 Jan 2019 03:07:20 -0500 Received: from nat-ies.mentorg.com ([192.94.31.2] helo=SVR-IES-MBX-04.mgc.mentorg.com) by relay1.mentorg.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-SHA384:256) id 1gey28-0001XP-Hl from Vladimir_Zapolskiy@mentor.com ; Thu, 03 Jan 2019 00:07:16 -0800 Received: from [137.202.108.130] (137.202.0.90) by SVR-IES-MBX-04.mgc.mentorg.com (139.181.222.4) with Microsoft SMTP Server (TLS) id 15.0.1320.4; Thu, 3 Jan 2019 08:07:12 +0000 Subject: Re: RFC: gpio: mmio: add support for 3 direction regs To: "Fried, Ramon" , , , References: <32edfd70-95dc-26a1-2ea6-143344cb2384@linux.intel.com> CC: , From: Vladimir Zapolskiy Message-ID: Date: Thu, 3 Jan 2019 10:07:11 +0200 User-Agent: Mozilla/5.0 (X11; Linux i686; rv:45.0) Gecko/20100101 Icedove/45.2.0 MIME-Version: 1.0 In-Reply-To: <32edfd70-95dc-26a1-2ea6-143344cb2384@linux.intel.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: SVR-IES-MBX-08.mgc.mentorg.com (139.181.222.8) To SVR-IES-MBX-04.mgc.mentorg.com (139.181.222.4) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ramon, On 01/03/2019 09:36 AM, Fried, Ramon wrote: > Hi. > > I'm working on a driver for STA2X11 GPIO controller who seems to fit > best to the generic mmio driver, I hope you have seen the existing driver drivers/gpio/gpio-sta2x11.c > the only problem I have is with the dir register case. The STA2X11 > has 3 registers for dir, one for data, one for set and one for > clear. The generic-mmio driver has support for this fashion for the > dat & set & clear registers but not for dirout/dirin registers. > > I wonder if support for this is generic enough to deserve a patch, if > so I'm willing to quickly add this support, if not, adding a flag > such as below, will allow partly using the generic mmio driver only > for set/get and the direction can be handled outside the driver. > If gpio-mmio fits well, then it might be simpler to set a flag BGPIOF_UNREADABLE_REG_DIR, then call bgpio_init() and then overwrite .direction_input, .direction_output and .get_direction callbacks, as a reference you can take a look at gpio-74xx-mmio.c -- Best wishes, Vladimir