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 95A44C43334 for ; Fri, 22 Jul 2022 16:02:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229880AbiGVQC5 (ORCPT ); Fri, 22 Jul 2022 12:02:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38362 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229771AbiGVQC5 (ORCPT ); Fri, 22 Jul 2022 12:02:57 -0400 Received: from relay10.mail.gandi.net (relay10.mail.gandi.net [217.70.178.230]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE48A17E3C; Fri, 22 Jul 2022 09:02:54 -0700 (PDT) Received: (Authenticated sender: alexandre.belloni@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id 5460224000C; Fri, 22 Jul 2022 16:02:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1658505773; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=cKG0lEYF348X//U1pESwwqdpnRBOQ0QEs5ZB22edgwM=; b=RgNRybfSVRwwGQB9674BRQtSIt3YcXmaOZRK1Gr2bUKatx6KUeQS6Vx1xDwfB2Uj9FWprO U/3BrpXAvYY/RPMUw77VaJ7BeSnLP28jkRVMKBEvurpdUB6+WnXX56jfKZrbgiGE2zDdGh Mlbwg01OocQkm7gnVWzH1ZxSHgSv0H45XFFKWPSTIPQNQQeIlC8nq25DcTjK914mQe3xwU 2e8vHjUZ0UGlCdlgm4s6Vyz/AsDAOWKfAjflTltyrFoWonxDhh34YJB5sF70bqUkNIwbqZ 96WSB6JESv+mFOiv5c86KL7gAlztgTywpR//qQU3AoFYdBKoQfgiOF0HQiakfA== Date: Fri, 22 Jul 2022 18:02:51 +0200 From: Alexandre Belloni To: Valentin CARON Cc: Alessandro Zummo , Rob Herring , Krzysztof Kozlowski , Alexandre Torgue , Gabriel Fernandez , Amelie Delaunay , linux-rtc@vger.kernel.org, devicetree@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/6] dt-bindings: rtc: stm32: add alarm A out property to select output Message-ID: References: <20220504130233.330983-1-valentin.caron@foss.st.com> <20220504130617.331290-1-valentin.caron@foss.st.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org On 23/05/2022 14:34:22+0200, Valentin CARON wrote: > Hi Alexandre, > > On 5/4/22 22:27, Alexandre Belloni wrote: > > Hello, > > > > On 04/05/2022 15:06:13+0200, Valentin Caron wrote: > > > STM32 RTC can pulse some SOC pins when an alarm of RTC expires. > > > > > > This patch adds property to activate alarm A output. The pulse can > > > output on three pins RTC_OUT1, RTC_OUT2, RTC_OUT2_RMP > > > (PC13, PB2, PI8 on stm32mp15) (PC13, PB2, PI1 on stm32mp13). > > > > > > Signed-off-by: Valentin Caron > > > --- > > > .../devicetree/bindings/rtc/st,stm32-rtc.yaml | 19 ++++++++++++++++++- > > > 1 file changed, 18 insertions(+), 1 deletion(-) > > > > > > diff --git a/Documentation/devicetree/bindings/rtc/st,stm32-rtc.yaml b/Documentation/devicetree/bindings/rtc/st,stm32-rtc.yaml > > > index 56d46ea35c5d..71e02604e8de 100644 > > > --- a/Documentation/devicetree/bindings/rtc/st,stm32-rtc.yaml > > > +++ b/Documentation/devicetree/bindings/rtc/st,stm32-rtc.yaml > > > @@ -59,6 +59,13 @@ properties: > > > Refer to for the supported values. > > > Pinctrl state named "default" may be defined to reserve pin for RTC output. > > > + st,alarm: > > > + $ref: "/schemas/types.yaml#/definitions/uint32" > > > + description: | > > > + To select and enable RTC Alarm A output. > > > + Refer to for the supported values. > > > + Pinctrl state named "default" may be defined to reserve pin for RTC output. > > > + > > > allOf: > > > - if: > > > properties: > > > @@ -75,6 +82,9 @@ allOf: > > > st,lsco: > > > maxItems: 0 > > > + st,alarm: > > > + maxItems: 0 > > > + > > > clock-names: false > > > required: > > > @@ -95,6 +105,9 @@ allOf: > > > st,lsco: > > > maxItems: 0 > > > + st,alarm: > > > + maxItems: 0 > > > + > > > required: > > > - clock-names > > > - st,syscfg > > > @@ -117,6 +130,9 @@ allOf: > > > st,lsco: > > > maxItems: 1 > > > + st,alarm: > > > + maxItems: 1 > > > + > > > required: > > > - clock-names > > > @@ -153,8 +169,9 @@ examples: > > > clocks = <&rcc RTCAPB>, <&rcc RTC>; > > > clock-names = "pclk", "rtc_ck"; > > > interrupts = ; > > > + st,alarm = ; > > > st,lsco = ; > > Shouldn't that be exactly the opposite? You have two pins that can > > output different functions. The property should be the pin and the value > > the function. I'd go even further and I would say this is actually > > pinmuxing. > > > You're right, if the property is the pin and the value the function, this > looks like a pinctrl node. > We choose to develop theses functionalities in the reverse order, to avoid > the complexity of adding > the pinctrl framework to our driver. Moreover, LSCO and AlarmA may haven't a > peripheral client and > this would probably require to also implement pinctrl hogging. > > Is the implementation that we have proposed is acceptable regarding theses > elements ? > I still think that the pin has to be the property and the function the value. Or we could find a generic name and provide an array of pin, function pair Or, go for pinmuxing My point here is that this is a common feature an RTCs and I don't want every vendor to come up with their own properties. Regards, -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com