From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754721AbbCMLT7 (ORCPT ); Fri, 13 Mar 2015 07:19:59 -0400 Received: from mail-wi0-f169.google.com ([209.85.212.169]:38136 "EHLO mail-wi0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754100AbbCMLTp (ORCPT ); Fri, 13 Mar 2015 07:19:45 -0400 Message-ID: <5502C7C8.1020002@gmail.com> Date: Fri, 13 Mar 2015 12:19:36 +0100 From: Matthias Brugger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Eddie Huang , Andrew Morton CC: rtc-linux@googlegroups.com, Alessandro Zummo , srv_heupstream@mediatek.com, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Grant Likely , Tianping Fang , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sascha Hauer , yh.chen@mediatek.com, yingjoe.chen@mediatek.com, linux-mediatek@lists.infradead.org Subject: Re: [rtc-linux] [PATCH 2/2] rtc: mediatek: Add MT63xx RTC driver References: <1422437276-41334-1-git-send-email-eddie.huang@mediatek.com> <1422437276-41334-3-git-send-email-eddie.huang@mediatek.com> <20150223135044.108ea32a65063a50aa36a309@linux-foundation.org> <1426242563.18291.19.camel@mtksdaap41> In-Reply-To: <1426242563.18291.19.camel@mtksdaap41> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13/03/15 11:29, Eddie Huang wrote: > > I encounter some trouble when I add code to check return value of > regmap_read and regmap_write. Every RTC register access through regmap, > and there are many register read/write in this driver. If I check every > return value, the driver will become ugly. I try to make this driver > clean using following macro. > > static int __rtc_read(struct mt6397_rtc *rtc, u32 offset, u32 *data) > { > u32 addr = rtc->addr_base + offset; > > if (offset < rtc->addr_range) > return regmap_read(rtc->regmap, addr, data); > > return -EINVAL; > } > > #define rtc_read(ret, rtc, offset, data) \ > ({ \ > ret = __rtc_read(rtc, offset, data); \ > if (ret < 0) \ > goto rtc_exit; \ > }) \ > I agree with Sascha on hiding a goto statement in a macro is not a good idea. > > And function call rtc_read, rtc_write looks like: > > static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm) > { > unsigned long time; > struct mt6397_rtc *rtc = dev_get_drvdata(dev); > int ret = 0; > u32 sec; > > mutex_lock(&rtc->lock); > do { > rtc_read(ret, rtc, RTC_TC_SEC, &tm->tm_sec); > rtc_read(ret, rtc, RTC_TC_MIN, &tm->tm_min); > rtc_read(ret, rtc, RTC_TC_HOU, &tm->tm_hour); > rtc_read(ret, rtc, RTC_TC_DOM, &tm->tm_mday); > rtc_read(ret, rtc, RTC_TC_MTH, &tm->tm_mon); > rtc_read(ret, rtc, RTC_TC_YEA, &tm->tm_year); > rtc_read(ret, rtc, RTC_TC_SEC, &sec); > } while (sec < tm->tm_sec); What about introducing static int __mtk_rtc_read_time(struct mt6397_rtc *rtc, struct rtc_time *tm, u32 *sec) and hide the checks of return values from regmap_read and the offset check in there. You return the error code or 0. This way the while loop would look like this: do { ret = __mtk_rtc_read_time(rtc, &tm, &sec); if (ret < 0) goto rtc_exit; } while (sec < tm->tm_sec); Best regards, Matthias From mboxrd@z Thu Jan 1 00:00:00 1970 From: matthias.bgg@gmail.com (Matthias Brugger) Date: Fri, 13 Mar 2015 12:19:36 +0100 Subject: [rtc-linux] [PATCH 2/2] rtc: mediatek: Add MT63xx RTC driver In-Reply-To: <1426242563.18291.19.camel@mtksdaap41> References: <1422437276-41334-1-git-send-email-eddie.huang@mediatek.com> <1422437276-41334-3-git-send-email-eddie.huang@mediatek.com> <20150223135044.108ea32a65063a50aa36a309@linux-foundation.org> <1426242563.18291.19.camel@mtksdaap41> Message-ID: <5502C7C8.1020002@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 13/03/15 11:29, Eddie Huang wrote: > > I encounter some trouble when I add code to check return value of > regmap_read and regmap_write. Every RTC register access through regmap, > and there are many register read/write in this driver. If I check every > return value, the driver will become ugly. I try to make this driver > clean using following macro. > > static int __rtc_read(struct mt6397_rtc *rtc, u32 offset, u32 *data) > { > u32 addr = rtc->addr_base + offset; > > if (offset < rtc->addr_range) > return regmap_read(rtc->regmap, addr, data); > > return -EINVAL; > } > > #define rtc_read(ret, rtc, offset, data) \ > ({ \ > ret = __rtc_read(rtc, offset, data); \ > if (ret < 0) \ > goto rtc_exit; \ > }) \ > I agree with Sascha on hiding a goto statement in a macro is not a good idea. > > And function call rtc_read, rtc_write looks like: > > static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm) > { > unsigned long time; > struct mt6397_rtc *rtc = dev_get_drvdata(dev); > int ret = 0; > u32 sec; > > mutex_lock(&rtc->lock); > do { > rtc_read(ret, rtc, RTC_TC_SEC, &tm->tm_sec); > rtc_read(ret, rtc, RTC_TC_MIN, &tm->tm_min); > rtc_read(ret, rtc, RTC_TC_HOU, &tm->tm_hour); > rtc_read(ret, rtc, RTC_TC_DOM, &tm->tm_mday); > rtc_read(ret, rtc, RTC_TC_MTH, &tm->tm_mon); > rtc_read(ret, rtc, RTC_TC_YEA, &tm->tm_year); > rtc_read(ret, rtc, RTC_TC_SEC, &sec); > } while (sec < tm->tm_sec); What about introducing static int __mtk_rtc_read_time(struct mt6397_rtc *rtc, struct rtc_time *tm, u32 *sec) and hide the checks of return values from regmap_read and the offset check in there. You return the error code or 0. This way the while loop would look like this: do { ret = __mtk_rtc_read_time(rtc, &tm, &sec); if (ret < 0) goto rtc_exit; } while (sec < tm->tm_sec); Best regards, Matthias