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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 960CBC433FE for ; Sat, 1 Oct 2022 16:11:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229702AbiJAQLK (ORCPT ); Sat, 1 Oct 2022 12:11:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43442 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229706AbiJAQLI (ORCPT ); Sat, 1 Oct 2022 12:11:08 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BD728671E; Sat, 1 Oct 2022 09:11:04 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A666EB8070D; Sat, 1 Oct 2022 16:11:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 426EDC433D6; Sat, 1 Oct 2022 16:11:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664640662; bh=+tLBwJLKoQXm1tSPzdom9fhATSE4ve/d6ppauhe85RU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ixzRqOMrsrhpJPO56KNiFtbHEDHRU3Bdq1G2MiFnrql6gnPYsSKb+qaRetAMo0t8O 3gKWaWAsyKYYvYYq7kzwWLJISlDp6DptC82bjJydASIvNR1+LX1Yn8n6lY4ZcWv7kh DOp0cxyFq1demqdPZRatUt+31mRsVXuOR1bq0JEzW6F4P72CwIFQUWOD35GAekDVi0 vYjD9UlL3JA1hXQxFJAZ1qtXPaYGovhthrPslHlRFWZ/f5cxNzaJhrBKX/5ZmKD2wF /jZ4vi96ihtcatVj3LvDOVKgdQEXLeV7a6xanmqcPSa1sXU9HxxlNp74N6tYWjhzwH zE282A4Yclm5Q== Received: by pali.im (Postfix) id 41C9FA15; Sat, 1 Oct 2022 18:10:59 +0200 (CEST) Date: Sat, 1 Oct 2022 18:10:59 +0200 From: Pali =?utf-8?B?Um9ow6Fy?= To: Lukas Wunner Cc: Vidya Sagar , bhelgaas@google.com, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, lpieralisi@kernel.org, kw@linux.com, thierry.reding@gmail.com, jonathanh@nvidia.com, mani@kernel.org, Sergey.Semin@baikalelectronics.ru, jszhang@kernel.org, linux-pci@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, kthota@nvidia.com, mmaddireddy@nvidia.com, sagar.tv@gmail.com, Marek =?utf-8?B?QmVow7pu?= , Jonathan Derrick Subject: Re: [PATCH V1 1/4] dt-bindings: Add "hotplug-gpios" PCIe property Message-ID: <20221001161059.5ymdptqzslh3d55x@pali> References: <20220930192747.21471-1-vidyas@nvidia.com> <20220930192747.21471-2-vidyas@nvidia.com> <20221001155626.GA9324@wunner.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221001155626.GA9324@wunner.de> User-Agent: NeoMutt/20180716 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Saturday 01 October 2022 17:56:26 Lukas Wunner wrote: > On Sat, Oct 01, 2022 at 12:57:44AM +0530, Vidya Sagar wrote: > > Provide a way for the firmware to tell the OS about the GPIO that can be > > used to get the Hot-Plug and Unplug events. > [...] > > --- a/Documentation/devicetree/bindings/pci/pci.txt > > +++ b/Documentation/devicetree/bindings/pci/pci.txt > > @@ -32,6 +32,10 @@ driver implementation may support the following properties: > > root port to downstream device and host bridge drivers can do programming > > which depends on CLKREQ signal existence. For example, programming root port > > not to advertise ASPM L1 Sub-States support if there is no CLKREQ signal. > > +- hotplug-gpios: > > + If present this property specifies the GPIO to be used for Hot-Plug/Unplug > > + functionality. It is used by the PCIe GPIO Hot-Plug core driver for > > + PCIe device Hot-Plug/Unplug events. > > Please specify the GPIO's semantics in more detail: > Is the pin high as long as presence of a card is detected? Hello! In PCIe is this semantics called "Presence Detect" (see PCIe Slot Capabilities). So should it be rather named "presence-detect-gpios" instead of hotplug? > Or does it pulse when a hotplug/unplug event occurs? > > Thanks, > > Lukas