rtc: pcf85063: keep the divider chain in reset during set_time

Sync from upstream linux v6.19.

Reviewed-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Signed-off-by: Alexander Feilke <alexander.feilke@ew.tq-group.com>

diff --git a/drivers/rtc/pcf85063.c b/drivers/rtc/pcf85063.c
index 06c85d939e05314b56407d6ef9373ee46d672a90..0b336b8c5ee2f2fdb4fa63baf049af7a00dc8153 100644 (file)
--- a/drivers/rtc/pcf85063.c
+++ b/drivers/rtc/pcf85063.c
@@ -68,12 +68,25 @@ static int pcf85063_get_time(struct udevice *dev, struct rtc_time *tm)
 static int pcf85063_set_time(struct udevice *dev, const struct rtc_time *tm)
 {
        u8 regs[7];
+       int rc;
 
        if (tm->tm_year < 2000 || tm->tm_year > 2099) {
                dev_err(dev, "Year must be between 2000 and 2099.\n");
                return -EINVAL;
        }
 
+       /*
+        * to accurately set the time, reset the divider chain and keep it in
+        * reset state until all time/date registers are written
+        */
+       rc = dm_i2c_reg_clrset(dev, PCF85063_REG_CTRL1,
+                              PCF85063_REG_CTRL1_EXT_TEST |
+                              PCF85063_REG_CTRL1_STOP,
+                              PCF85063_REG_CTRL1_STOP);
+
+       if (rc)
+               return rc;
+
        /* hours, minutes and seconds */
        regs[0] = bin2bcd(tm->tm_sec) & (~PCF85063_REG_SC_OS);
 
@@ -91,7 +104,17 @@ static int pcf85063_set_time(struct udevice *dev, const struct rtc_time *tm)
        /* adjust register to match rtc_time spec */
        regs[6] = bin2bcd(tm->tm_year % 100);
 
-       return dm_i2c_write(dev, PCF85063_REG_SC, regs, sizeof(regs));
+       rc = dm_i2c_write(dev, PCF85063_REG_SC, regs, sizeof(regs));
+       if (rc)
+               return rc;
+
+       /*
+        * Write the control register as a separate action since the size of
+        * the register space is different between the PCF85063TP and
+        * PCF85063A devices. The rollover point can not be used.
+        */
+       return dm_i2c_reg_clrset(dev, PCF85063_REG_CTRL1,
+                                PCF85063_REG_CTRL1_STOP, 0);
 }
 
 static int pcf85063_reset(struct udevice *dev)