RTC_IMSC
imsc = readl(ldata->base + RTC_IMSC);
writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC);
writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC);
alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;
alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI;