linux-kernel - [PATCH 7/7] rtc: ingenic: Reset regulator register in probe

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Date:   Wed,  6 May 2020 00:13:36 +0200
From:   Paul Cercueil <paul@...pouillou.net>
To:     Alessandro Zummo <a.zummo@...ertech.it>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>
Cc:     od@...c.me, linux-rtc@...r.kernel.org,
        linux-kernel@...r.kernel.org, Paul Cercueil <paul@...pouillou.net>
Subject: [PATCH 7/7] 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@...pouillou.net>
---
 drivers/rtc/rtc-jz4740.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/rtc/rtc-jz4740.c b/drivers/rtc/rtc-jz4740.c
index 65e130726fc6..9607e6b6e0b3 100644
--- 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;
-- 
2.26.2