3 files changed, 80 insertions, 10 deletions

diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index b0cb9a35f5cd..d76179878ff9 100644
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
@@ -132,9 +132,9 @@ static const struct iio_dma_buffer_ops iio_dmaengine_default_ops = {
 static ssize_t iio_dmaengine_buffer_get_length_align(struct device *dev,
 	struct device_attribute *attr, char *buf)
 {
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
 	struct dmaengine_buffer *dmaengine_buffer =
-		iio_buffer_to_dmaengine_buffer(indio_dev->buffer);
+		iio_buffer_to_dmaengine_buffer(buffer);
 
 	return sprintf(buf, "%zu\n", dmaengine_buffer->align);
 }
@@ -244,7 +244,7 @@ static void __devm_iio_dmaengine_buffer_free(struct device *dev, void *res)
  *
  * The buffer will be automatically de-allocated once the device gets destroyed.
  */
-struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
+static struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
 	const char *channel)
 {
 	struct iio_buffer **bufferp, *buffer;
@@ -265,7 +265,34 @@ struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
 
 	return buffer;
 }
-EXPORT_SYMBOL_GPL(devm_iio_dmaengine_buffer_alloc);
+
+/**
+ * devm_iio_dmaengine_buffer_setup() - Setup a DMA buffer for an IIO device
+ * @dev: Parent device for the buffer
+ * @indio_dev: IIO device to which to attach this buffer.
+ * @channel: DMA channel name, typically "rx".
+ *
+ * This allocates a new IIO buffer with devm_iio_dmaengine_buffer_alloc()
+ * and attaches it to an IIO device with iio_device_attach_buffer().
+ * It also appends the INDIO_BUFFER_HARDWARE mode to the supported modes of the
+ * IIO device.
+ */
+int devm_iio_dmaengine_buffer_setup(struct device *dev,
+				    struct iio_dev *indio_dev,
+				    const char *channel)
+{
+	struct iio_buffer *buffer;
+
+	buffer = devm_iio_dmaengine_buffer_alloc(indio_dev->dev.parent,
+						 channel);
+	if (IS_ERR(buffer))
+		return PTR_ERR(buffer);
+
+	indio_dev->modes |= INDIO_BUFFER_HARDWARE;
+
+	return iio_device_attach_buffer(indio_dev, buffer);
+}
+EXPORT_SYMBOL_GPL(devm_iio_dmaengine_buffer_setup);
 
 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 MODULE_DESCRIPTION("DMA buffer for the IIO framework");
diff --git a/drivers/iio/buffer/industrialio-triggered-buffer.c b/drivers/iio/buffer/industrialio-triggered-buffer.c
index 92b8aea3e063..b2b1b7d27af4 100644
--- a/drivers/iio/buffer/industrialio-triggered-buffer.c
+++ b/drivers/iio/buffer/industrialio-triggered-buffer.c
@@ -50,8 +50,6 @@ int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev,
 		goto error_ret;
 	}
 
-	iio_device_attach_buffer(indio_dev, buffer);
-
 	indio_dev->pollfunc = iio_alloc_pollfunc(h,
 						 thread,
 						 IRQF_ONESHOT,
@@ -72,10 +70,16 @@ int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev,
 
 	buffer->attrs = buffer_attrs;
 
+	ret = iio_device_attach_buffer(indio_dev, buffer);
+	if (ret < 0)
+		goto error_dealloc_pollfunc;
+
 	return 0;
 
+error_dealloc_pollfunc:
+	iio_dealloc_pollfunc(indio_dev->pollfunc);
 error_kfifo_free:
-	iio_kfifo_free(indio_dev->buffer);
+	iio_kfifo_free(buffer);
 error_ret:
 	return ret;
 }
diff --git a/drivers/iio/buffer/kfifo_buf.c b/drivers/iio/buffer/kfifo_buf.c
index 1359abed3b31..516eb3465de1 100644
--- a/drivers/iio/buffer/kfifo_buf.c
+++ b/drivers/iio/buffer/kfifo_buf.c
@@ -180,13 +180,13 @@ static void devm_iio_kfifo_release(struct device *dev, void *res)
 }
 
 /**
- * devm_iio_fifo_allocate - Resource-managed iio_kfifo_allocate()
+ * devm_iio_kfifo_allocate - Resource-managed iio_kfifo_allocate()
  * @dev:		Device to allocate kfifo buffer for
  *
  * RETURNS:
  * Pointer to allocated iio_buffer on success, NULL on failure.
  */
-struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
+static struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
 {
 	struct iio_buffer **ptr, *r;
 
@@ -204,6 +204,45 @@ struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
 
 	return r;
 }
-EXPORT_SYMBOL(devm_iio_kfifo_allocate);
+
+/**
+ * devm_iio_kfifo_buffer_setup_ext - Allocate a kfifo buffer & attach it to an IIO device
+ * @dev: Device object to which to attach the life-time of this kfifo buffer
+ * @indio_dev: The device the buffer should be attached to
+ * @mode_flags: The mode flags for this buffer (INDIO_BUFFER_SOFTWARE and/or
+ *		INDIO_BUFFER_TRIGGERED).
+ * @setup_ops: The setup_ops required to configure the HW part of the buffer (optional)
+ * @buffer_attrs: Extra sysfs buffer attributes for this IIO buffer
+ *
+ * This function allocates a kfifo buffer via devm_iio_kfifo_allocate() and
+ * attaches it to the IIO device via iio_device_attach_buffer().
+ * This is meant to be a bit of a short-hand/helper function as there are a few
+ * drivers that seem to do this.
+ */
+int devm_iio_kfifo_buffer_setup_ext(struct device *dev,
+				    struct iio_dev *indio_dev,
+				    int mode_flags,
+				    const struct iio_buffer_setup_ops *setup_ops,
+				    const struct attribute **buffer_attrs)
+{
+	struct iio_buffer *buffer;
+
+	if (!mode_flags)
+		return -EINVAL;
+
+	buffer = devm_iio_kfifo_allocate(dev);
+	if (!buffer)
+		return -ENOMEM;
+
+	mode_flags &= kfifo_access_funcs.modes;
+
+	indio_dev->modes |= mode_flags;
+	indio_dev->setup_ops = setup_ops;
+
+	buffer->attrs = buffer_attrs;
+
+	return iio_device_attach_buffer(indio_dev, buffer);
+}
+EXPORT_SYMBOL_GPL(devm_iio_kfifo_buffer_setup_ext);
 
 MODULE_LICENSE("GPL");