Hi,

Not much to add, apart from the spinlock issue already spotted by Andrew.

On 27/08/2017 at 02:33:27 +0200, Andreas Färber wrote:

+struct rtd119x_rtc {
+	void __iomem *base;
+	struct clk *clk;
+	struct rtc_device *rtcdev;
+	unsigned base_year;

checkpatch complains this should be made unsigned int

+	spinlock_t lock;
+};
+
+static inline int rtd119x_rtc_year_days(int year)
+{
+	return rtc_year_days(1, 12, year);

I'm not sure it is worth wrapping rtc_year_days

+static int rtd119x_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rtd119x_rtc *data = dev_get_drvdata(dev);
+	unsigned long flags;
+	s32 day;
+	u32 sec;
+	unsigned year;

unsigned int

+	int tries = 0;
+
+	spin_lock_irqsave(&data->lock, flags);
+
+ while (true) {
+     tm->tm_sec = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1;
+     tm->tm_min  = readl_relaxed(data->base + RTD_RTCMIN) & RTD_RTCMIN_RTCMIN_MASK;
+     tm->tm_hour = readl_relaxed(data->base + RTD_RTCHR) & RTD_RTCHR_RTCHR_MASK;
+     day  =  readl_relaxed(data->base + RTD_RTCDATE1) & RTD_RTCDATE1_RTCDATE1_MASK;
+     day |= (readl_relaxed(data->base + RTD_RTCDATE2) & RTD_RTCDATE2_RTCDATE2_MASK) << 8;
+     sec  = (readl_relaxed(data->base + RTD_RTCSEC) & RTD_RTCSEC_RTCSEC_MASK) >> 1;
+     tries++;
+
+     if (sec == tm->tm_sec)
+         break;
+
+     if (tries >= 3) {
+         spin_unlock_irqrestore(&data->lock, flags);
+         return -EINVAL;
+     }
+ }
+ if (tries > 1)
+     dev_dbg(dev, "%s: needed %i tries\n", __func__, tries);
+
+ spin_unlock_irqrestore(&data->lock, flags);
+
+ year = data->base_year;
+ while (day >= rtd119x_rtc_year_days(year)) {
+     day -= rtd119x_rtc_year_days(year);
+     year++;
+ }
+ tm->tm_year = year - 1900;
+ tm->tm_yday = day;
+
+ tm->tm_mon = 0;
+ while (day >= rtc_month_days(tm->tm_mon, year)) {
+     day -= rtc_month_days(tm->tm_mon, year);
+     tm->tm_mon++;
+ }
+ tm->tm_mday = day + 1;
+
+ return rtc_valid_tm(tm);

As you spotted, you can return 0 here.

+}
+
+static int rtd119x_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	struct rtd119x_rtc *data = dev_get_drvdata(dev);
+	unsigned long flags;
+	unsigned day;

ditto


-- 
Alexandre Belloni, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com