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path: root/drivers/rtc/rtc-pcf85063.c
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Diffstat (limited to 'drivers/rtc/rtc-pcf85063.c')
-rw-r--r--drivers/rtc/rtc-pcf85063.c46
1 files changed, 39 insertions, 7 deletions
diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
index 283c2335b01b..f6ce63c443a0 100644
--- a/drivers/rtc/rtc-pcf85063.c
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -27,17 +27,11 @@
*/
#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
#define PCF85063_REG_SC 0x04 /* datetime */
#define PCF85063_REG_SC_OS 0x80
-#define PCF85063_REG_MN 0x05
-#define PCF85063_REG_HR 0x06
-#define PCF85063_REG_DM 0x07
-#define PCF85063_REG_DW 0x08
-#define PCF85063_REG_MO 0x09
-#define PCF85063_REG_YR 0x0A
static struct i2c_driver pcf85063_driver;
@@ -180,6 +174,39 @@ 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 +224,11 @@ 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);