rtc: ds1307: improve trickle charger initialization

Instead of storing the trickle_charger_setup value in struct chip_desc
we can let function ds1307_trickle_init return it because it's used
in the probe function only.
This allows us to constify struct chip_desc variables in a next step.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index eecf6b2..5a3c563 100644 (file)
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -141,7 +141,6 @@ struct chip_desc {
        u8                      century_bit;
        u8                      bbsqi_bit;
        u16                     trickle_charger_reg;
-       u8                      trickle_charger_setup;
        u8                      (*do_trickle_setup)(struct ds1307 *, uint32_t,
                                                    bool);
 };
@@ -941,23 +940,23 @@ static u8 do_trickle_setup_ds1339(struct ds1307 *ds1307,
        return setup;
 }
 
-static void ds1307_trickle_init(struct ds1307 *ds1307,
-                               struct chip_desc *chip)
+static u8 ds1307_trickle_init(struct ds1307 *ds1307,
+                             struct chip_desc *chip)
 {
-       uint32_t ohms = 0;
+       uint32_t ohms;
        bool diode = true;
 
        if (!chip->do_trickle_setup)
-               goto out;
+               return 0;
+
        if (device_property_read_u32(ds1307->dev, "trickle-resistor-ohms",
                                     &ohms))
-               goto out;
+               return 0;
+
        if (device_property_read_bool(ds1307->dev, "trickle-diode-disable"))
                diode = false;
-       chip->trickle_charger_setup = chip->do_trickle_setup(ds1307,
-                                                            ohms, diode);
-out:
-       return;
+
+       return chip->do_trickle_setup(ds1307, ohms, diode);
 }
 
 /*----------------------------------------------------------------------*/
@@ -1319,6 +1318,7 @@ static int ds1307_probe(struct i2c_client *client,
        struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
        struct rtc_time         tm;
        unsigned long           timestamp;
+       u8                      trickle_charger_setup = 0;
 
        irq_handler_t   irq_handler = ds1307_irq;
 
@@ -1359,18 +1359,17 @@ static int ds1307_probe(struct i2c_client *client,
        }
 
        if (!pdata)
-               ds1307_trickle_init(ds1307, chip);
+               trickle_charger_setup = ds1307_trickle_init(ds1307, chip);
        else if (pdata->trickle_charger_setup)
-               chip->trickle_charger_setup = pdata->trickle_charger_setup;
+               trickle_charger_setup = pdata->trickle_charger_setup;
 
-       if (chip->trickle_charger_setup && chip->trickle_charger_reg) {
+       if (trickle_charger_setup && chip->trickle_charger_reg) {
+               trickle_charger_setup |= DS13XX_TRICKLE_CHARGER_MAGIC;
                dev_dbg(ds1307->dev,
                        "writing trickle charger info 0x%x to 0x%x\n",
-                   DS13XX_TRICKLE_CHARGER_MAGIC | chip->trickle_charger_setup,
-                   chip->trickle_charger_reg);
+                       trickle_charger_setup, chip->trickle_charger_reg);
                regmap_write(ds1307->regmap, chip->trickle_charger_reg,
-                   DS13XX_TRICKLE_CHARGER_MAGIC |
-                   chip->trickle_charger_setup);
+                            trickle_charger_setup);
        }
 
        buf = ds1307->regs;