rtc: rv8803: factor out existing register initialization to function

The driver probe currently initializes some registers to non-POR
values. These values are not reinstated if the RTC experiences voltage
loss later on. Prepare for fixing this by factoring out the
initialization to a separate function.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220426071056.1187235-2-s.hauer@pengutronix.de

diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c
index f69e0b1137cd02659ae07d22f4b3f8eda856cd85..c880f8d6c74234cc40f0d8ac0751631471f744c3 100644 (file)
--- a/drivers/rtc/rtc-rv8803.c
+++ b/drivers/rtc/rtc-rv8803.c
@@ -64,6 +64,7 @@ struct rv8803_data {
        struct rtc_device *rtc;
        struct mutex flags_lock;
        u8 ctrl;
+       u8 backup;
        enum rv8803_type type;
 };
 
@@ -498,18 +499,32 @@ static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
        if (err < 0)
                return err;
 
-       flags = ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF) & (u8)err;
-
-       if (of_property_read_bool(node, "epson,vdet-disable"))
-               flags |= RX8900_FLAG_VDETOFF;
-
-       if (of_property_read_bool(node, "trickle-diode-disable"))
-               flags |= RX8900_FLAG_SWOFF;
+       flags = (u8)err;
+       flags &= ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF);
+       flags |= rv8803->backup;
 
        return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL,
                                         flags);
 }
 
+/* configure registers with values different than the Power-On reset defaults */
+static int rv8803_regs_configure(struct rv8803_data *rv8803)
+{
+       int err;
+
+       err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
+       if (err)
+               return err;
+
+       err = rx8900_trickle_charger_init(rv8803);
+       if (err) {
+               dev_err(&rv8803->client->dev, "failed to init charger\n");
+               return err;
+       }
+
+       return 0;
+}
+
 static int rv8803_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
 {
@@ -576,15 +591,15 @@ static int rv8803_probe(struct i2c_client *client,
        if (!client->irq)
                clear_bit(RTC_FEATURE_ALARM, rv8803->rtc->features);
 
-       err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
-       if (err)
-               return err;
+       if (of_property_read_bool(client->dev.of_node, "epson,vdet-disable"))
+               rv8803->backup |= RX8900_FLAG_VDETOFF;
 
-       err = rx8900_trickle_charger_init(rv8803);
-       if (err) {
-               dev_err(&client->dev, "failed to init charger\n");
+       if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable"))
+               rv8803->backup |= RX8900_FLAG_SWOFF;
+
+       err = rv8803_regs_configure(rv8803);
+       if (err)
                return err;
-       }
 
        rv8803->rtc->ops = &rv8803_rtc_ops;
        rv8803->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;