iio: core: implement devm_iio_device_alloc/devm_iio_device_free

Add a resource managed devm_iio_device_alloc()/devm_iio_device_free()
to automatically clean up any allocations made by IIO drivers,
thus leading to simplified IIO drivers code.

In addition, this will allow IIO drivers to use other devm_*() API
(like devm_request_irq) and don't care about the race between
iio_device_free() and the release of resources by Device core
during driver removing.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
Tested-by: Oleksandr Kravchenko <o.v.kravchenko@globallogic.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 25 insertions, 0 deletions

diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index 3d35b7023591..61d220f89aca 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -532,6 +532,31 @@ static inline struct iio_dev *iio_priv_to_dev(void *priv)
 void iio_device_free(struct iio_dev *indio_dev);
 
 /**
+ * devm_iio_device_alloc - Resource-managed iio_device_alloc()
+ * @dev:                Device to allocate iio_dev for
+ * @sizeof_priv:        Space to allocate for private structure.
+ *
+ * Managed iio_device_alloc.  iio_dev allocated with this function is
+ * automatically freed on driver detach.
+ *
+ * If an iio_dev allocated with this function needs to be freed separately,
+ * devm_iio_device_free() must be used.
+ *
+ * RETURNS:
+ * Pointer to allocated iio_dev on success, NULL on failure.
+ */
+struct iio_dev *devm_iio_device_alloc(struct device *dev, int sizeof_priv);
+
+/**
+ * devm_iio_device_free - Resource-managed iio_device_free()
+ * @dev:                Device this iio_dev belongs to
+ * @indio_dev:          the iio_dev associated with the device
+ *
+ * Free indio_dev allocated with devm_iio_device_alloc().
+ */
+void devm_iio_device_free(struct device *dev, struct iio_dev *iio_dev);
+
+/**
  * iio_buffer_enabled() - helper function to test if the buffer is enabled
  * @indio_dev:          IIO device structure for device
  **/