DS13XX_TRICKLE_CHARGER_MAGIC sets the trickle-charge select (TCS) bits (7..4). The datasheet of Maxim Integrated's DS1339 [1] for instance reads: "To prevent accidental enabling, only a pattern on 1010 enables the trickle charger. All other patterns disable the trickle charger." Since not all RTCs connected to a backup battery or supercap use these bits DS13XX_TRICKLE_CHARGER_MAGIC should not get applied for all charger setups unconditionally. Epson's RX8130 is such an example: Instead of TCS bits "SMPTSEL1", "SMPTSEL0", "CHGEN" and "INIEN" are expected as bit 7..4. DS1339 and DS1340 are currently the only RTCs in the ds1307 driver that apply DS13XX_TRICKLE_CHARGER_MAGIC to their setup register value. So apply DS13XX_TRICKLE_CHARGER_MAGIC in do_trickle_setup_ds1339() which is used by both RTCs. [1] https://datasheets.maximintegrated.com/en/ds/DS1339-DS1339U.pdf [2] https://support.epson.biz/td/api/doc_check.php?dl=app_RX8130CE Signed-off-by: Bastian Krause <bst@xxxxxxxxxxxxxx> --- No previous version. --- drivers/rtc/rtc-ds1307.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 54c85cdd019d..ff5242d10b21 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -507,6 +507,8 @@ static u8 do_trickle_setup_ds1339(struct ds1307 *ds1307, u32 ohms, bool diode) u8 setup = (diode) ? DS1307_TRICKLE_CHARGER_DIODE : DS1307_TRICKLE_CHARGER_NO_DIODE; + setup |= DS13XX_TRICKLE_CHARGER_MAGIC; + switch (ohms) { case 250: setup |= DS1307_TRICKLE_CHARGER_250_OHM; @@ -1758,7 +1760,6 @@ static int ds1307_probe(struct i2c_client *client, trickle_charger_setup = pdata->trickle_charger_setup; 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", trickle_charger_setup, chip->trickle_charger_reg); -- 2.28.0
