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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 3513AC433F4 for ; Wed, 29 Aug 2018 08:02:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E39DA2086D for ; Wed, 29 Aug 2018 08:02:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E39DA2086D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727658AbeH2L6W (ORCPT ); Wed, 29 Aug 2018 07:58:22 -0400 Received: from mail.bootlin.com ([62.4.15.54]:42271 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726656AbeH2L6V (ORCPT ); Wed, 29 Aug 2018 07:58:21 -0400 Received: by mail.bootlin.com (Postfix, from userid 110) id 8034C20795; Wed, 29 Aug 2018 10:02:41 +0200 (CEST) Received: from windsurf (AAubervilliers-681-1-53-19.w90-88.abo.wanadoo.fr [90.88.170.19]) by mail.bootlin.com (Postfix) with ESMTPSA id 10BED206EE; Wed, 29 Aug 2018 10:02:31 +0200 (CEST) Date: Wed, 29 Aug 2018 10:02:29 +0200 From: Thomas Petazzoni To: Linus Walleij Cc: aditya@kobol.io, "thierry.reding@gmail.com" , Thomas Petazzoni , Jason Cooper , "open list:GPIO SUBSYSTEM" , Richard Genoud , Gregory Clement , gauthier@kobol.io, Alban Browaeys , linux-pwm@vger.kernel.org, "linux-kernel@vger.kernel.org" , dennis@ausil.us, Ralph Sennhauser , Andrew Lunn Subject: Re: [PATCH RESEND 1/2] gpio: mvebu: Add support for multiple PWM lines per GPIO chip Message-ID: <20180829100229.7566e0db@windsurf> In-Reply-To: References: <1533522556-55055-1-git-send-email-aditya@kobol.io> <1533522556-55055-2-git-send-email-aditya@kobol.io> Organization: Bootlin (formerly Free Electrons) X-Mailer: Claws Mail 3.15.1-dirty (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Linus, On Wed, 29 Aug 2018 09:54:04 +0200, Linus Walleij wrote: > On Mon, Aug 6, 2018 at 4:31 AM Aditya Prayoga wrote: > > > Allow more than 1 PWM request (eg. PWM fan) on the same GPIO chip. > > > > based on initial work on LK4.4 by Alban Browaeys. > > URL: https://github.com/helios-4/linux-marvell/commit/743ae97 > > [Aditya Prayoga: forward port, cleanup] > > Signed-off-by: Aditya Prayoga > > It would be awesome to get some feedback from the MVEBU maintainers > on this patch set. > > Who are most active on Marvell stuff these days? Thomas? Andrew Lunn did the initial support for PWM in this driver, and he outlined in the commit log the limitation of his first implementation: However, there are only two sets of PWM configuration registers for all the GPIO lines. This driver simply allows a single GPIO line per GPIO chip of 32 lines to be used as a PWM. Attempts to use more return EBUSY. Andrew, perhaps you could review the patch posted by Aditya, since you already looked at PWM support on mvebu platforms ? Thanks! Thomas -- Thomas Petazzoni, CTO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com