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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_2 autolearn=no 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 CD6D2C3A5A1 for ; Thu, 22 Aug 2019 12:34:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9B72423402 for ; Thu, 22 Aug 2019 12:34:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388676AbfHVMeY (ORCPT ); Thu, 22 Aug 2019 08:34:24 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:49386 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1730918AbfHVMeX (ORCPT ); Thu, 22 Aug 2019 08:34:23 -0400 X-UUID: 31f219a7482b44259f289d9290bf75da-20190822 X-UUID: 31f219a7482b44259f289d9290bf75da-20190822 Received: from mtkexhb01.mediatek.inc [(172.21.101.102)] by mailgw01.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.10 Build 0707 with TLS) with ESMTP id 1694480463; Thu, 22 Aug 2019 20:34:17 +0800 Received: from MTKCAS36.mediatek.inc (172.27.4.186) by mtkmbs07n2.mediatek.inc (172.21.101.141) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Thu, 22 Aug 2019 20:34:11 +0800 Received: from [10.17.3.153] (172.27.4.253) by MTKCAS36.mediatek.inc (172.27.4.170) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Thu, 22 Aug 2019 20:34:10 +0800 Message-ID: <1566477254.12318.41.camel@mhfsdcap03> Subject: Re: [PATCH v2 2/4] rtc: Add support for the MediaTek MT2712 RTC From: Ran Bi To: Alexandre Belloni CC: Rob Herring , Matthias Brugger , Alessandro Zummo , "Mark Rutland" , Mauro Carvalho Chehab , "David S . Miller" , Greg Kroah-Hartman , Jonathan Cameron , Linus Walleij , Nicolas Ferre , , , , , , , YT Shen , Eddie Huang , Yingjoe Chen , "Flora Fu" , Sean Wang Date: Thu, 22 Aug 2019 20:34:14 +0800 In-Reply-To: <20190820201744.GZ3545@piout.net> References: <20190801110122.26834-1-ran.bi@mediatek.com> <20190801110122.26834-3-ran.bi@mediatek.com> <20190820201744.GZ3545@piout.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-MTK: N Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org Hi, > > + > > +#define MTK_RTC_DEV KBUILD_MODNAME > > You probably shouldn't do that and have a static string for the driver > name. I probably doesn't matter much though because DT is used to probe > the driver. > Will change it at next patch. > > +/* we map HW YEAR 0 to 2000 because 2000 is the leap year */ > > +#define MT2712_MIN_YEAR 2000 > > +#define MT2712_BASE_YEAR 1900 > > +#define MT2712_MIN_YEAR_OFFSET (MT2712_MIN_YEAR - MT2712_BASE_YEAR) > > +#define MT2712_MAX_YEAR_OFFSET (MT2712_MIN_YEAR_OFFSET + 127) > > + > > All those defines are unecessary, see below. > Will change it at next patch. > > +struct mt2712_rtc { > > + struct device *dev; > > Looking at the code closely, it seems this is only used for debug and > error messages. Maybe you could use rtc_dev->dev instead. > Will change it at next patch. > > + mutex_lock(&rtc->rtc_dev->ops_lock); > > + > > + irqsta = mt2712_readl(rtc, MT2712_IRQ_STA); > > Do you have to lock that read? Is the register cleared on read? > Yes, this register is read clear register. > > + do { > > + __mt2712_rtc_read_time(rtc, tm, &sec); > > + } while (sec < tm->tm_sec); /* SEC has carried */ > > Shouldn't that be while (tm->tm_sec < sec)? > In __mt2712_rtc_read_time function, we read tm->tm_sec before read sec. Sometimes we can meet situation like "tm->tm_sec == 59" and "sec == 0". It means that TC_SEC has carried and we need to reload the tm struct. I suppose it was correct that using "while (sec < tm->tm_sec)" > > + > > + /* HW register use 7 bits to store year data, minus > > + * MT2712_MIN_YEAR_OFFSET brfore write year data to register, and plus > > + * MT2712_MIN_YEAR_OFFSET back after read year from register > > + */ > > + tm->tm_year += MT2712_MIN_YEAR_OFFSET; > > Simply add 100 in __mt2712_rtc_read_time > Will change it at next patch. > > + > > + /* HW register start mon from one, but tm_mon start from zero. */ > > + tm->tm_mon--; > > + > > You can also do that in __mt2712_rtc_read_time. > Will change it at next patch. > > + if (rtc_valid_tm(tm)) { > > This check is unnecessary, the validity is always checked by the core. > Will remove this at next patch. > > + if (tm->tm_year > MT2712_MAX_YEAR_OFFSET) { > > + dev_dbg(rtc->dev, "Set year %d out of range. (%d - %d)\n", > > + 1900 + tm->tm_year, 1900 + MT2712_MIN_YEAR_OFFSET, > > + 1900 + MT2712_MAX_YEAR_OFFSET); > > + return -EINVAL; > > + } > > This check is unnecessary, see below. > Will change it at next patch. > > + > > + tm->tm_year -= MT2712_MIN_YEAR_OFFSET; > > + tm->tm_mon++; > > You should probably avoid modifying tm, move the substraction and > addition in the mt2712_writel calls. > Will change it at next patch. > > + if (tm->tm_year > MT2712_MAX_YEAR_OFFSET) { > > + dev_dbg(rtc->dev, "Set year %d out of range. (%d - %d)\n", > > + 1900 + tm->tm_year, 1900 + MT2712_MIN_YEAR_OFFSET, > > + 1900 + MT2712_MAX_YEAR_OFFSET); > > + return -EINVAL; > > + } > > + > > Unnecessary check. > Will change it at next patch. > > + p1 = mt2712_readl(rtc, MT2712_POWERKEY1); > > + p2 = mt2712_readl(rtc, MT2712_POWERKEY2); > > + if (p1 != MT2712_POWERKEY1_KEY || p2 != MT2712_POWERKEY2_KEY) > > + dev_dbg(rtc->dev, "powerkey not set (lost power)\n"); > > + > > This info is valuable, you should check that when reading the time and > return -EINVAL if power was lost. > Will change it at next patch. > > > + /* RTC need POWERKEY1/2 match, then goto normal work mode */ > > + mt2712_writel(rtc, MT2712_POWERKEY1, MT2712_POWERKEY1_KEY); > > + mt2712_writel(rtc, MT2712_POWERKEY2, MT2712_POWERKEY2_KEY); > > This should be written when setting the time after power was lost. > I suppose we can move this into mt2712_rtc_read_time function's "if (p1 != MT2712_POWERKEY1_KEY || p2 != MT2712_POWERKEY2_KEY)" condition which will be added at next patch. We need additional flag to mark this condition or another if condition in mt2712_rtc_set_time fucntion if we put these code in mt2712_rtc_set_time function. > > +static const struct rtc_class_ops mt2712_rtc_ops = { > > + .read_time = mt2712_rtc_read_time, > > + .set_time = mt2712_rtc_set_time, > > + .read_alarm = mt2712_rtc_read_alarm, > > + .set_alarm = mt2712_rtc_set_alarm, > > For proper operations, you should also provide the .alarm_irq_enable > callback. > Will change it at next patch. > > + rtc->rtc_dev->ops = &mt2712_rtc_ops; > > If you set the range properly here using rtc_dev->range_min and > rtc_dev->range_max, then the core will be able to do range checking and > will also take care of the year offset/windowing calculations instead of > having to hardcode that in the driver. > Will change it at next patch. Best Regards, Ran