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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB1AEC433EF for ; Wed, 10 Nov 2021 14:30:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C193461106 for ; Wed, 10 Nov 2021 14:30:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232176AbhKJOd2 (ORCPT ); Wed, 10 Nov 2021 09:33:28 -0500 Received: from smtp2.axis.com ([195.60.68.18]:64193 "EHLO smtp2.axis.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232035AbhKJOd2 (ORCPT ); Wed, 10 Nov 2021 09:33:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=axis.com; q=dns/txt; s=axis-central1; t=1636554641; x=1668090641; h=subject:to:cc:references:from:message-id:date: mime-version:in-reply-to:content-transfer-encoding; bh=9kI++ufZhv3l81MzwqI23PjZg4/Jwqnhj/RwRBkqNWI=; b=oMvmPYkGaaGSQrAnFQ3GcvTT3U3JzrfYj7D7YX3CssQg2Es8eIIwEAja cg38D9O7JIqI7iUfUMlfR4q54CUWGX1T7VhuIA8VTgn3kPmnRAmgiSpdN 8cftsGEKWZ6bbCmBU7ImmK3wny0A79QGN2Dl1jyCLprRkZ2klssn8iRQl ejL+/JxUPApykuF4V2vyznAH53g3uRO2YxIqtGIWL3TayxeKuhBKvJYQl /yj0JJEC+x03ed2Y6zg7VEyc4F5bp/VUnDPhrrsR5GF+pwNo9q25d5pz1 ier2CHhYUO27hoYhpAIkoYLnM+4cwzMOj1Yi+AwHRH6i6OU5qvsggJx7T w==; Subject: Re: [PATCH] rtc: rs5c372: Add RTC_VL_READ, RTC_VL_CLR ioctls To: Alexandre Belloni , Camel Guo CC: Alessandro Zummo , kernel , "linux-rtc@vger.kernel.org" , "linux-kernel@vger.kernel.org" References: <20211110115455.18699-1-camel.guo@axis.com> <2303e635-dbd0-1730-cc6f-84021eb37223@axis.com> From: Camel Guo Message-ID: Date: Wed, 10 Nov 2021 15:30:39 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.0.5.60] X-ClientProxiedBy: se-mail06w.axis.com (10.20.40.12) To se-mail03w.axis.com (10.20.40.9) Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org Hello, On 11/10/21 3:27 PM, Alexandre Belloni wrote: > On 10/11/2021 15:03:49+0100, Camel Guo wrote: >> > On 10/11/2021 12:54:54+0100, Camel Guo wrote: >> > > From: Camel Guo >> > > +     switch (cmd) { >> > > +     case RTC_VL_READ: >> > > +             flags = 0; >> > > + >> > > +             switch (rs5c->type) { >> > > +             case rtc_r2025sd: >> > > +             case rtc_r2221tl: >> > > +                     if ((rs5c->type == rtc_r2025sd && !(ctrl2 & R2x2x_CTRL2_XSTP)) || >> > > +                             (rs5c->type == rtc_r2221tl &&  (ctrl2 & R2x2x_CTRL2_XSTP))) { >> > > +                             flags |= RTC_VL_DATA_INVALID; >> > > +                     } >> > > +                     if (ctrl2 & R2x2x_CTRL2_VDET) >> > > +                             flags |= RTC_VL_ACCURACY_LOW; >> > >> > Shouldn't that be RTC_VL_BACKUP_LOW? >> >> Some drivers (e.g: rv3029_ioctl and rv8803_ioctl) use RTC_VL_ACCURACY_LOW, >> but some other drivers (e.g: abx80x_ioctl, pcf2127_rtc_ioctl and >> pcf8523_rtc_ioctl) use RTC_VL_BACKUP_LOW instead. Is there any guideline or >> document telling the differences between them? >> > > RTC_VL_BACKUP_LOW: The backup voltage is low > RTC_VL_ACCURACY_LOW: the primary or backup voltage is low, temperature > compensation (or similar) has stopped Then I agree that we should go for RTC_VL_BACKUP_LOW. > > -- > Alexandre Belloni, co-owner and COO, Bootlin > Embedded Linux and Kernel engineering > https://bootlin.com