Issue: - # hwclock -w hwclock: RTC_SET_TIME: Invalid argument Why: - Relative patch: https://lkml.org/lkml/2019/4/3/55 , this patch will always check for unwritable registers, it will compare reg with max_register in regmap_writeable. - In drivers/rtc/rtc-pcf85363.c, CTRL_STOP_EN is 0x2e, but DT_100THS is 0, max_regiter is 0x2f, then reg will be equal to 0x30, '0x30 < 0x2f' is false,so regmap_writeable will return false. - Root cause: the buf[] was written to a wrong place in the file drivers/rtc/rtc-pcf85363.c How: - Split of writing regs to two parts, first part writes control registers about stop_enable and resets, second part writes RTC time and date registers. Signed-off-by: Biwen Li <biwen.li@xxxxxxx> --- Change in v2: - add Why and How into commit message. drivers/rtc/rtc-pcf85363.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c index a075e77617dc..3450d615974d 100644 --- a/drivers/rtc/rtc-pcf85363.c +++ b/drivers/rtc/rtc-pcf85363.c @@ -166,7 +166,12 @@ static int pcf85363_rtc_set_time(struct device *dev, struct rtc_time *tm) buf[DT_YEARS] = bin2bcd(tm->tm_year % 100); ret = regmap_bulk_write(pcf85363->regmap, CTRL_STOP_EN, - tmp, sizeof(tmp)); + tmp, 2); + if (ret) + return ret; + + ret = regmap_bulk_write(pcf85363->regmap, DT_100THS, + buf, sizeof(tmp) - 2); if (ret) return ret; -- 2.17.1