All of the parts supported by this driver can make use of a
small capacitor to improve the accuracy of the autocalibration
process for their RC oscillators. If a capacitor is connected,
a configuration register must be set to enable its use, so a
new Device Tree property has been added for that purpose.
Signed-off-by: Kevin P. Fleming <kevin+linux@xxxxxxx>
Cc: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
To: linux-rtc@xxxxxxxxxxxxxxx
To: devicetree@xxxxxxxxxxxxxxx
---
v2: Change property to an integer value to allow user to enable or disable
drivers/rtc/rtc-abx80x.c | 35 ++++++++++++++++++++++++++++++++++-
1 file changed, 34 insertions(+), 1 deletion(-)
diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index daa6f27040e61..8edfcefbd9058 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -77,6 +77,10 @@
#define ABX8XX_CFG_KEY_OSC 0xa1
#define ABX8XX_CFG_KEY_MISC 0x9d
+#define ABX8XX_REG_AFCTRL 0x26
+#define ABX8XX_AUTOCAL_FILTER_DISABLE 0x00
+#define ABX8XX_AUTOCAL_FILTER_ENABLE 0xa0
+
#define ABX8XX_REG_ID0 0x28
#define ABX8XX_REG_OUT_CTRL 0x30
@@ -141,6 +145,26 @@ static int abx80x_is_rc_mode(struct i2c_client *client)
return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
}
+static int abx80x_set_autocal_filter(struct i2c_client *client, u8 filter_cfg)
+{
+ int err;
+
+ /*
+ * Write the configuration key register to enable access to the AFCTRL
+ * register
+ */
+ if (abx80x_write_config_key(client, ABX8XX_CFG_KEY_MISC) < 0)
+ return -EIO;
+
+ err = i2c_smbus_write_byte_data(client, ABX8XX_REG_AFCTRL, filter_cfg);
+ if (err < 0) {
+ dev_warn(&client->dev, "Unable to write autocal filter register\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
static int abx80x_enable_trickle_charger(struct i2c_client *client,
u8 trickle_cfg)
{
@@ -678,7 +702,7 @@ static int abx80x_probe(struct i2c_client *client,
{
struct device_node *np = client->dev.of_node;
struct abx80x_priv *priv;
- int i, data, err, trickle_cfg = -EINVAL;
+ int i, data, err, trickle_cfg, filter_cfg = -EINVAL;
char buf[7];
unsigned int part = id->driver_data;
unsigned int partnumber;
@@ -824,6 +848,15 @@ static int abx80x_probe(struct i2c_client *client,
return err;
}
+ if (of_property_read_u32(np, "abracon,autocal_filter", &filter_cfg) == 0) {
+ err = abx80x_set_autocal_filter(client,
+ filter_cfg ?
+ ABX8XX_AUTOCAL_FILTER_ENABLE :
+ ABX8XX_AUTOCAL_FILTER_DISABLE);
+ if (err)
+ return err;
+ }
+
if (client->irq > 0) {
dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
--
2.26.2
