rtc: ingenic: Reset regulator register in probe

The regulator register specifies how many input clock cycles (minus one)
are contained in one tick of the 1 Hz clock.

Since this register can contain bogus values after the system boots, it
needs to be reset in the probe register, otherwise the RTC may count way
to slow or way too fast.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20200505221336.222313-7-paul@crapouillou.net
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/rtc/rtc-jz4740.c b/drivers/rtc/rtc-jz4740.c
index 65e130726fc6d5fd985b61fc6dc3f287dee38a8e..9607e6b6e0b32e584528c8d40f6e12e0d61a495f 100644 (file)
--- a/drivers/rtc/rtc-jz4740.c
+++ b/drivers/rtc/rtc-jz4740.c
@@ -372,6 +372,9 @@ static int jz4740_rtc_probe(struct platform_device *pdev)
        rate = clk_get_rate(clk);
        jz4740_rtc_set_wakeup_params(rtc, np, rate);
 
+       /* Each 1 Hz pulse should happen after (rate) ticks */
+       jz4740_rtc_reg_write(rtc, JZ_REG_RTC_REGULATOR, rate - 1);
+
        ret = rtc_register_device(rtc->rtc);
        if (ret)
                return ret;