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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 5FBB1C19437 for ; Tue, 8 Dec 2020 14:07:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3788623A69 for ; Tue, 8 Dec 2020 14:07:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729552AbgLHOHy (ORCPT ); Tue, 8 Dec 2020 09:07:54 -0500 Received: from mout.kundenserver.de ([217.72.192.74]:60269 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729462AbgLHOHy (ORCPT ); Tue, 8 Dec 2020 09:07:54 -0500 Received: from [192.168.1.155] ([95.117.39.192]) by mrelayeu.kundenserver.de (mreue109 [212.227.15.183]) with ESMTPSA (Nemesis) id 1Mzhax-1jzus61WUL-00viD2; Tue, 08 Dec 2020 15:05:07 +0100 Subject: Re: Howto listen to/handle gpio state changes ? Re: [PATCH v2 2/2] drivers: gpio: add virtio-gpio guest driver To: Linus Walleij , Bartosz Golaszewski Cc: "Enrico Weigelt, metux IT consult" , "linux-kernel@vger.kernel.org" , Jonathan Corbet , "Michael S. Tsirkin" , Jason Wang , Linux Doc Mailing List , "open list:GPIO SUBSYSTEM" , virtualization@lists.linux-foundation.org, linux-riscv@lists.infradead.org References: <20201203191135.21576-1-info@metux.net> <20201203191135.21576-2-info@metux.net> <0080d492-2f07-d1c6-d18c-73d4204a5d40@metux.net> From: "Enrico Weigelt, metux IT consult" Message-ID: <51d3efb7-b7eb-83d7-673a-308dd51616d3@metux.net> Date: Tue, 8 Dec 2020 15:04:50 +0100 User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: tl Content-Transfer-Encoding: 8bit X-Provags-ID: V03:K1:G4pb0xE5H22ojPKBimkPJ8QHTZy9Ztkg67vq+dnwAqAyIP7Owjp PtM4xLyYwEOsOB5Jeky7p0oHn4OV0smr3NYA6ZBFzuAz8Wj154fwdKeJAA7RKqTpXhphJ0A KZ+KK0E+bN0KXeCyh8zH7Zs4RpyqkMmgg1F2DoLmutar7t2c9swfhYmzbPPLxZS31ACp14U zhqcJNgYORsE2qZ0/AFTw== X-UI-Out-Filterresults: notjunk:1;V03:K0:a0Ff9jNvXYo=:mUVNahr6lKpBJFzi+wLba2 BTDIDBHKoHwdSkhKUdoqJmrbqtF3ZYCKFqGIgJUBJmegkGz/SOcu3pd2KOd4s2s3/QuXaNdk0 uguRGeRDIcNPst62WfMtiwo4Iw/Vunm5FNmfJFeatXDqWazimqqDCanpscLSdrblTa20JB1VW c7kuVDEz155jDxAxRrlCHa4xGdgZYPY0yAQaS4Dv3uUFDVLnMUFpMkDRsUEKPq4noO6+ucdvE SRzQXp3T1n3zUjTN8U0oP43qsyQntWyl1RTCSoXTQO9xSgs89oOoNRoJT2rv1BUKKBfwqnqmI LpZWwaBmU/uSsj4PGpYC4o/F9bS7XDbzC7/lddp5AyIn8cCAKy4qL8gpxMSWZ9sTqpjvl4Hqq 945/WLdlpTWKQh+Nbd0YlPUVBPRRhnU8HM133F3fS5h9vHMLhveOWfk66rqfG Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08.12.20 10:38, Linus Walleij wrote: Hi, > This is Bartosz territory, but the gpio-mockup.c driver will insert > IRQs into the system, he went and added really core stuff > into kernel/irq to make this happen. Notice that in Kconfig > it does: > > select IRQ_SIM > > Then this is used: > include/linux/irq_sim.h > > This is intended for simulating IRQs and both GPIO and IIO use it. > I think this inserts IRQs from debugfs and I have no idea how > flexible that is. Oh, thx. It seems to implement a pseudo-irqchip driver. I've already though about doing that, but didn't think its worth it, just for my driver alone. I've implemented a few irq handling cb's directly the driver. But since we already have it, I'll reconsider :) BUT: this wasn't exactly my question :p I've been looking for some more direct notification callback for gpio consumers: here the consumer would register itself as a listener on some gpio_desc and called back when something changes (with data what exactly changed, eg. "gpio #3 input switched to high"). Seems we currently just have the indirect path via interrupts. --mtx -- --- Hinweis: unverschlüsselte E-Mails können leicht abgehört und manipuliert werden ! Für eine vertrauliche Kommunikation senden Sie bitte ihren GPG/PGP-Schlüssel zu. --- Enrico Weigelt, metux IT consult Free software and Linux embedded engineering info@metux.net -- +49-151-27565287