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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 792A0C43603 for ; Thu, 19 Dec 2019 10:23:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 574DF2064B for ; Thu, 19 Dec 2019 10:23:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726699AbfLSKXZ (ORCPT ); Thu, 19 Dec 2019 05:23:25 -0500 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:50759 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726664AbfLSKXZ (ORCPT ); Thu, 19 Dec 2019 05:23:25 -0500 X-Originating-IP: 90.65.102.129 Received: from localhost (lfbn-lyo-1-1670-129.w90-65.abo.wanadoo.fr [90.65.102.129]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id B198020010; Thu, 19 Dec 2019 10:23:21 +0000 (UTC) Date: Thu, 19 Dec 2019 11:23:21 +0100 From: Alexandre Belloni To: Eugen.Hristev@microchip.com Cc: jic23@kernel.org, robh+dt@kernel.org, Nicolas.Ferre@microchip.com, linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rtc@vger.kernel.org, a.zummo@towertech.it, Ludovic.Desroches@microchip.com Subject: Re: [PATCH 04/10] rtc: at91rm9200: use of_platform_populate as return value Message-ID: <20191219102321.GR695889@piout.net> References: <1576686157-11939-1-git-send-email-eugen.hristev@microchip.com> <1576686157-11939-5-git-send-email-eugen.hristev@microchip.com> <20191218164348.GN695889@piout.net> <04264cb0-61a9-aba3-82ad-e7d12fd8441e@microchip.com> <20191218165831.GO695889@piout.net> <91cc67e1-7e14-f7b9-da77-b16d9e158f20@microchip.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <91cc67e1-7e14-f7b9-da77-b16d9e158f20@microchip.com> Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org On 19/12/2019 09:15:02+0000, Eugen.Hristev@microchip.com wrote: > > > On 18.12.2019 18:58, Alexandre Belloni wrote: > > On 18/12/2019 16:52:21+0000, Eugen.Hristev@microchip.com wrote: > >> > >> > >> On 18.12.2019 18:43, Alexandre Belloni wrote: > >> > >>> Hi, > >>> > >>> On 18/12/2019 16:24:00+0000, Eugen.Hristev@microchip.com wrote: > >>>> From: Eugen Hristev > >>>> > >>>> This allows the RTC node to have child nodes in DT. > >>>> This allows subnodes to be probed. > >>>> > >>>> Signed-off-by: Eugen Hristev > >>>> --- > >>>> drivers/rtc/rtc-at91rm9200.c | 2 +- > >>>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>>> > >>>> diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c > >>>> index 3b833e0..f1b5b3d 100644 > >>>> --- a/drivers/rtc/rtc-at91rm9200.c > >>>> +++ b/drivers/rtc/rtc-at91rm9200.c > >>>> @@ -421,7 +421,7 @@ static int __init at91_rtc_probe(struct platform_device *pdev) > >>>> at91_rtc_write_ier(AT91_RTC_SECEV); > >>>> > >>>> dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n"); > >>>> - return 0; > >>>> + return of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev); > >>>> > >>> > >>> You can avoid the DT binding change and DT parsing by using > >>> platform_add_device here. I don't think there is any point describing > >>> the trigger as a child node (a watchdog functionality wouldn't be > >>> described for example). > >>> > >> > >> Hi, > >> > >> It's needed because the ADC needs a link to the trigger device. This is > >> a hardware link inside the SoC, so I thought the best way is to describe > >> this hardware is in the Device Tree. > >> Otherwise the ADC node is unaware of the RTC triggering possibility. > >> If we just assign the RTC trigger device to the ADC through the sysfs, > >> the ADC cannot distinguish between the RTC trigger and other various > >> triggers which can be attached. > >> > > > > I'm not sure this links is required but I will let Jonathan review. Even > > if it is needed, you can still use the rtc node to describe that link. > > Actually, the RTC node could potentially have two different ADC > triggers. There is another OUT1 field that can do a second trigger for > the ADC only for the last channel. Future development might add this > trigger, so, with that in mind, I think it's best to link the exact > trigger and not the RTC node. Nothing prevents you from using an index with the phandle (and I would add a type in that case then). Having subnodes in the DT is not really a good idea. The IP is the RTC, it just happens to have some outputs. See what has been done for the PMC. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com