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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 06F0AC43219 for ; Tue, 30 Apr 2019 11:58:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D64C72075E for ; Tue, 30 Apr 2019 11:58:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726894AbfD3L6r (ORCPT ); Tue, 30 Apr 2019 07:58:47 -0400 Received: from relay5-d.mail.gandi.net ([217.70.183.197]:35847 "EHLO relay5-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730650AbfD3LrE (ORCPT ); Tue, 30 Apr 2019 07:47:04 -0400 X-Originating-IP: 109.213.14.175 Received: from localhost (alyon-652-1-31-175.w109-213.abo.wanadoo.fr [109.213.14.175]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay5-d.mail.gandi.net (Postfix) with ESMTPSA id 1D5E31C000C; Tue, 30 Apr 2019 11:47:02 +0000 (UTC) Date: Tue, 30 Apr 2019 13:47:02 +0200 From: Alexandre Belloni To: Baruch Siach Cc: linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 2/4] rtc: digicolor: set range Message-ID: <20190430114702.GD11339@piout.net> References: <20190430093212.28425-1-alexandre.belloni@bootlin.com> <20190430093212.28425-2-alexandre.belloni@bootlin.com> <877ebbu3lz.fsf@tarshish> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <877ebbu3lz.fsf@tarshish> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/04/2019 14:36:24+0300, Baruch Siach wrote: > Hi Alexandre, > > On Tue, Apr 30 2019, Alexandre Belloni wrote: > > > While the range of REFERENCE + TIME is actually 33 bits, the counter > > itself (TIME) is a 32-bits seconds counter. > > > > Signed-off-by: Alexandre Belloni > > --- > > drivers/rtc/rtc-digicolor.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/rtc/rtc-digicolor.c b/drivers/rtc/rtc-digicolor.c > > index 5bb14c56bc9a..e6e16aaac254 100644 > > --- a/drivers/rtc/rtc-digicolor.c > > +++ b/drivers/rtc/rtc-digicolor.c > > @@ -206,6 +206,7 @@ static int __init dc_rtc_probe(struct platform_device *pdev) > > platform_set_drvdata(pdev, rtc); > > > > rtc->rtc_dev->ops = &dc_rtc_ops; > > + rtc->rtc_dev->range_max = U32_MAX; > > Where can I find documentation on the meaning and usage of the range_max > value? I could not find anything in the kernel source. > It should be set to the maximum UNIX timestamp the RTC can be set to while keeping range_min to range_max contiguous. In the digicolor case, you could go up to 8589934590 (Wed Mar 16 12:56:30 UTC 2242) but the driver only writes DC_RTC_REFERENCE and I'm not sure it can also update DC_RTC_TIME safely. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com