[PATCH RFC 1/6] iio: core: Match iio_device_claim_*() return semantics

[Kurt Borja <kuurtb@gmail.com>]

In order to improve API consistency with conditional locks, use
true/false return semantics in iio_device_claim_buffer_mode().

This also matches iio_device_claim_direct() return semantics.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
 drivers/iio/adc/ade9000.c                                 | 2 +-
 drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c | 5 +----
 drivers/iio/health/max30100.c                             | 2 +-
 drivers/iio/health/max30102.c                             | 2 +-
 drivers/iio/industrialio-core.c                           | 8 ++++----
 drivers/iio/light/opt4060.c                               | 2 +-
 include/linux/iio/iio.h                                   | 2 +-
 7 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/iio/adc/ade9000.c b/drivers/iio/adc/ade9000.c
index 2de8a718d62a..b345c4d1ef24 100644
--- a/drivers/iio/adc/ade9000.c
+++ b/drivers/iio/adc/ade9000.c
@@ -964,7 +964,7 @@ static irqreturn_t ade9000_dready_thread(int irq, void *data)
 	struct iio_dev *indio_dev = data;
 
 	/* Handle data ready interrupt from C4/EVENT/DREADY pin */
-	if (!iio_device_claim_buffer_mode(indio_dev)) {
+	if (iio_device_claim_buffer_mode(indio_dev)) {
 		ade9000_iio_push_buffer(indio_dev);
 		iio_device_release_buffer_mode(indio_dev);
 	}
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index 9ac80e4b7d75..8ed4b2e410c8 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -188,11 +188,8 @@ int cros_ec_sensors_push_data(struct iio_dev *indio_dev,
 	/*
 	 * Ignore samples if the buffer is not set: it is needed if the ODR is
 	 * set but the buffer is not enabled yet.
-	 *
-	 * Note: iio_device_claim_buffer_mode() returns -EBUSY if the buffer
-	 * is not enabled.
 	 */
-	if (iio_device_claim_buffer_mode(indio_dev) < 0)
+	if (!iio_device_claim_buffer_mode(indio_dev))
 		return 0;
 
 	out = (s16 *)st->samples;
diff --git a/drivers/iio/health/max30100.c b/drivers/iio/health/max30100.c
index 3d441013893c..3f3680c4b42f 100644
--- a/drivers/iio/health/max30100.c
+++ b/drivers/iio/health/max30100.c
@@ -417,7 +417,7 @@ static int max30100_read_raw(struct iio_dev *indio_dev,
 		 * Temperature reading can only be acquired while engine
 		 * is running
 		 */
-		if (iio_device_claim_buffer_mode(indio_dev)) {
+		if (!iio_device_claim_buffer_mode(indio_dev)) {
 			/*
 			 * Replacing -EBUSY or other error code
 			 * returned by iio_device_claim_buffer_mode()
diff --git a/drivers/iio/health/max30102.c b/drivers/iio/health/max30102.c
index a48c0881a4c7..288c2f37a4a2 100644
--- a/drivers/iio/health/max30102.c
+++ b/drivers/iio/health/max30102.c
@@ -476,7 +476,7 @@ static int max30102_read_raw(struct iio_dev *indio_dev,
 		 * shutdown; leave shutdown briefly when buffer not running
 		 */
 any_mode_retry:
-		if (iio_device_claim_buffer_mode(indio_dev)) {
+		if (!iio_device_claim_buffer_mode(indio_dev)) {
 			/*
 			 * This one is a *bit* hacky. If we cannot claim buffer
 			 * mode, then try direct mode so that we make sure
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index f69deefcfb6f..a10590ac4e17 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -2224,19 +2224,19 @@ EXPORT_SYMBOL_GPL(__iio_device_release_direct);
  *
  * Use with iio_device_release_buffer_mode().
  *
- * Returns: 0 on success, -EBUSY on failure.
+ * Returns: true on success, false on failure.
  */
-int iio_device_claim_buffer_mode(struct iio_dev *indio_dev)
+bool iio_device_claim_buffer_mode(struct iio_dev *indio_dev)
 {
 	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
 
 	mutex_lock(&iio_dev_opaque->mlock);
 
 	if (iio_buffer_enabled(indio_dev))
-		return 0;
+		return true;
 
 	mutex_unlock(&iio_dev_opaque->mlock);
-	return -EBUSY;
+	return false;
 }
 EXPORT_SYMBOL_GPL(iio_device_claim_buffer_mode);
 
diff --git a/drivers/iio/light/opt4060.c b/drivers/iio/light/opt4060.c
index 981c704e7df5..8cb3fa38077e 100644
--- a/drivers/iio/light/opt4060.c
+++ b/drivers/iio/light/opt4060.c
@@ -304,7 +304,7 @@ static int opt4060_set_driver_state(struct iio_dev *indio_dev,
 	struct opt4060_chip *chip = iio_priv(indio_dev);
 	int ret = 0;
 any_mode_retry:
-	if (iio_device_claim_buffer_mode(indio_dev)) {
+	if (!iio_device_claim_buffer_mode(indio_dev)) {
 		/*
 		 * This one is a *bit* hacky. If we cannot claim buffer mode,
 		 * then try direct mode so that we make sure things cannot
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 872ebdf0dd77..bf7b7337ff1b 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -687,7 +687,7 @@ static inline void iio_device_release_direct(struct iio_dev *indio_dev)
 	__release(indio_dev);
 }
 
-int iio_device_claim_buffer_mode(struct iio_dev *indio_dev);
+bool iio_device_claim_buffer_mode(struct iio_dev *indio_dev);
 void iio_device_release_buffer_mode(struct iio_dev *indio_dev);
 
 extern const struct bus_type iio_bus_type;

-- 
2.52.0