From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Allows use of:
CLASS(iio_claim_direct, claimed_dev)(indio_dev);
if (IS_ERR(claimed_dev))
return PTR_ERR(claimed_dev);
st = iio_priv(claimed_dev);
to automatically call iio_device_release_direct_mode() based on scope.
Typically seen in combination with local device specific locks which
are already have automated cleanup options via guard(mutex)(&st->lock)
and scoped_guard(). Using both together allows most error handling to
be automated.
Note that whilst this pattern results in a struct iio_dev *claimed_dev
that can be used, it is not necessary to do so as long as that pointer
has been checked for errors as in the example.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
drivers/iio/industrialio-core.c | 4 ++++
include/linux/iio/iio.h | 25 +++++++++++++++++++++++++
2 files changed, 29 insertions(+)
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index c77745b594bd..93bfad105eb5 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -2065,6 +2065,10 @@ EXPORT_SYMBOL_GPL(iio_device_claim_direct_mode);
*/
void iio_device_release_direct_mode(struct iio_dev *indio_dev)
{
+ /* Auto cleanup can result in this being called with an ERR_PTR */
+ if (IS_ERR(indio_dev))
+ return;
+
mutex_unlock(&to_iio_dev_opaque(indio_dev)->mlock);
}
EXPORT_SYMBOL_GPL(iio_device_release_direct_mode);
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index d0ce3b71106a..11c42170fda1 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -9,6 +9,7 @@
#include <linux/device.h>
#include <linux/cdev.h>
+#include <linux/cleanup.h>
#include <linux/slab.h>
#include <linux/iio/types.h>
/* IIO TODO LIST */
@@ -644,6 +645,30 @@ int __devm_iio_device_register(struct device *dev, struct iio_dev *indio_dev,
int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp);
int iio_device_claim_direct_mode(struct iio_dev *indio_dev);
void iio_device_release_direct_mode(struct iio_dev *indio_dev);
+/*
+ * Auto cleanup version of iio_device_claim_direct_mode,
+ *
+ * CLASS(iio_claim_direct, claimed_dev)(indio_dev);
+ * if (IS_ERR(claimed_dev))
+ * return PTR_ERR(claimed_dev);
+ *
+ * st = iio_priv(claimed_dev);
+ * ....
+ */
+DEFINE_CLASS(iio_claim_direct, struct iio_dev *,
+ iio_device_release_direct_mode(_T),
+ ({
+ struct iio_dev *dev;
+ int d = iio_device_claim_direct_mode(_T);
+
+ if (d < 0)
+ dev = ERR_PTR(d);
+ else
+ dev = _T;
+ dev;
+ }),
+ struct iio_dev *_T);
+
int iio_device_claim_buffer_mode(struct iio_dev *indio_dev);
void iio_device_release_buffer_mode(struct iio_dev *indio_dev);
--
2.42.0
