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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html