iio: imu: adis: add unlocked __adis_initial_startup()

This change splits the __adis_initial_startup() away from
adis_initial_startup(). The unlocked version can be used in certain calls
during probe, where races won't happen since the ADIS driver may not be
registered yet with IIO.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/adis.c

@@ -365,7 +365,7 @@ static int adis_self_test(struct adis *adis)
 }
 
 /**
- * adis_inital_startup() - Performs device self-test
+ * __adis_initial_startup() - Device initial setup
  * @adis: The adis device
  *
  * Returns 0 if the device is operational, a negative error code otherwise.
@@ -373,28 +373,22 @@ static int adis_self_test(struct adis *adis)
  * This function should be called early on in the device initialization sequence
  * to ensure that the device is in a sane and known state and that it is usable.
  */
-int adis_initial_startup(struct adis *adis)
+int __adis_initial_startup(struct adis *adis)
 {
 	int ret;
 
-	mutex_lock(&adis->state_lock);
-
 	ret = adis_self_test(adis);
 	if (ret) {
 		dev_err(&adis->spi->dev, "Self-test failed, trying reset.\n");
 		__adis_reset(adis);
 		ret = adis_self_test(adis);
-		if (ret) {
+		if (ret)
 			dev_err(&adis->spi->dev, "Second self-test failed, giving up.\n");
-			goto out_unlock;
-		}
 	}
 
-out_unlock:
-	mutex_unlock(&adis->state_lock);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(adis_initial_startup);
+EXPORT_SYMBOL_GPL(__adis_initial_startup);
 
 /**
  * adis_single_conversion() - Performs a single sample conversion

include/linux/iio/imu/adis.h

@@ -297,6 +297,7 @@ static inline int adis_read_reg_32(struct adis *adis, unsigned int reg,
 
 int adis_enable_irq(struct adis *adis, bool enable);
 int __adis_check_status(struct adis *adis);
+int __adis_initial_startup(struct adis *adis);
 
 static inline int adis_check_status(struct adis *adis)
 {
@@ -309,7 +310,17 @@ static inline int adis_check_status(struct adis *adis)
 	return ret;
 }
 
-int adis_initial_startup(struct adis *adis);
+/* locked version of __adis_initial_startup() */
+static inline int adis_initial_startup(struct adis *adis)
+{
+	int ret;
+
+	mutex_lock(&adis->state_lock);
+	ret = __adis_initial_startup(adis);
+	mutex_unlock(&adis->state_lock);
+
+	return ret;
+}
 
 int adis_single_conversion(struct iio_dev *indio_dev,
 	const struct iio_chan_spec *chan, unsigned int error_mask,