diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c index 283c2335b01b..b79af6e96292 100644 --- a/drivers/rtc/rtc-pcf85063.c +++ b/drivers/rtc/rtc-pcf85063.c @@ -27,6 +27,7 @@ */ #define PCF85063_REG_CTRL1 0x00 /* status */ +#define PCF85063_REG_CTRL1_CAP_SEL BIT(0) #define PCF85063_REG_CTRL1_STOP BIT(5) #define PCF85063_REG_CTRL2 0x01 @@ -180,6 +181,39 @@ static const struct rtc_class_ops pcf85063_rtc_ops = { .set_time = pcf85063_rtc_set_time }; +static int pcf85063_load_capacitance(struct i2c_client *client) +{ + u32 load; + int rc; + u8 reg; + + rc = i2c_smbus_read_byte_data(client, PCF85063_REG_CTRL1); + if (rc < 0) + return rc; + + reg = rc; + load = 7000; + of_property_read_u32(client->dev.of_node, "quartz-load-femtofarads", + &load); + + switch (load) { + default: + dev_warn(&client->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 7000", + load); + /* fall through */ + case 7000: + reg &= ~PCF85063_REG_CTRL1_CAP_SEL; + break; + case 12500: + reg |= PCF85063_REG_CTRL1_CAP_SEL; + break; + } + + rc = i2c_smbus_write_byte_data(client, PCF85063_REG_CTRL1, reg); + + return rc; +} + static int pcf85063_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -197,6 +231,11 @@ static int pcf85063_probe(struct i2c_client *client, return err; } + err = pcf85063_load_capacitance(client); + if (err < 0) + dev_warn(&client->dev, "failed to set xtal load capacitance: %d", + err); + rtc = devm_rtc_device_register(&client->dev, pcf85063_driver.driver.name, &pcf85063_rtc_ops, THIS_MODULE);