iio: buffer-dmaengine: add dev-managed calls for buffer alloc

Currently, when using a 'iio_dmaengine_buffer_alloc()', an matching call to
'iio_dmaengine_buffer_free()' must be made.

With this change, this can be avoided by using
'devm_iio_dmaengine_buffer_alloc()'. The buffer will get free'd via the
device's devres handling.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index 94da3b1..6dedf12 100644 (file)
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
@@ -229,6 +229,45 @@ void iio_dmaengine_buffer_free(struct iio_buffer *buffer)
 }
 EXPORT_SYMBOL_GPL(iio_dmaengine_buffer_free);
 
+static void __devm_iio_dmaengine_buffer_free(struct device *dev, void *res)
+{
+       iio_dmaengine_buffer_free(*(struct iio_buffer **)res);
+}
+
+/**
+ * devm_iio_dmaengine_buffer_alloc() - Resource-managed iio_dmaengine_buffer_alloc()
+ * @dev: Parent device for the buffer
+ * @channel: DMA channel name, typically "rx".
+ *
+ * This allocates a new IIO buffer which internally uses the DMAengine framework
+ * to perform its transfers. The parent device will be used to request the DMA
+ * channel.
+ *
+ * The buffer will be automatically de-allocated once the device gets destroyed.
+ */
+struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
+       const char *channel)
+{
+       struct iio_buffer **bufferp, *buffer;
+
+       bufferp = devres_alloc(__devm_iio_dmaengine_buffer_free,
+                              sizeof(*bufferp), GFP_KERNEL);
+       if (!bufferp)
+               return ERR_PTR(-ENOMEM);
+
+       buffer = iio_dmaengine_buffer_alloc(dev, channel);
+       if (IS_ERR(buffer)) {
+               devres_free(bufferp);
+               return buffer;
+       }
+
+       *bufferp = buffer;
+       devres_add(dev, bufferp);
+
+       return buffer;
+}
+EXPORT_SYMBOL_GPL(devm_iio_dmaengine_buffer_alloc);
+
 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 MODULE_DESCRIPTION("DMA buffer for the IIO framework");
 MODULE_LICENSE("GPL");

diff --git a/include/linux/iio/buffer-dmaengine.h b/include/linux/iio/buffer-dmaengine.h
index b3a5744..0e503db 100644 (file)
--- a/include/linux/iio/buffer-dmaengine.h
+++ b/include/linux/iio/buffer-dmaengine.h
@@ -14,4 +14,7 @@ struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,
        const char *channel);
 void iio_dmaengine_buffer_free(struct iio_buffer *buffer);
 
+struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
+                                                  const char *channel);
+
 #endif