1 files changed, 48 insertions, 38 deletions

diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index a18c1da292..918f6f8d65 100644
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
@@ -64,14 +64,25 @@ static int iio_dmaengine_buffer_submit_block(struct iio_dma_buffer_queue *queue,
 	struct dmaengine_buffer *dmaengine_buffer =
 		iio_buffer_to_dmaengine_buffer(&queue->buffer);
 	struct dma_async_tx_descriptor *desc;
+	enum dma_transfer_direction dma_dir;
+	size_t max_size;
 	dma_cookie_t cookie;
 
-	block->bytes_used = min(block->size, dmaengine_buffer->max_size);
-	block->bytes_used = round_down(block->bytes_used,
-			dmaengine_buffer->align);
+	max_size = min(block->size, dmaengine_buffer->max_size);
+	max_size = round_down(max_size, dmaengine_buffer->align);
+
+	if (queue->buffer.direction == IIO_BUFFER_DIRECTION_IN) {
+		block->bytes_used = max_size;
+		dma_dir = DMA_DEV_TO_MEM;
+	} else {
+		dma_dir = DMA_MEM_TO_DEV;
+	}
+
+	if (!block->bytes_used || block->bytes_used > max_size)
+		return -EINVAL;
 
 	desc = dmaengine_prep_slave_single(dmaengine_buffer->chan,
-		block->phys_addr, block->bytes_used, DMA_DEV_TO_MEM,
+		block->phys_addr, block->bytes_used, dma_dir,
 		DMA_PREP_INTERRUPT);
 	if (!desc)
 		return -ENOMEM;
@@ -112,12 +123,14 @@ static void iio_dmaengine_buffer_release(struct iio_buffer *buf)
 
 static const struct iio_buffer_access_funcs iio_dmaengine_buffer_ops = {
 	.read = iio_dma_buffer_read,
+	.write = iio_dma_buffer_write,
 	.set_bytes_per_datum = iio_dma_buffer_set_bytes_per_datum,
 	.set_length = iio_dma_buffer_set_length,
 	.request_update = iio_dma_buffer_request_update,
 	.enable = iio_dma_buffer_enable,
 	.disable = iio_dma_buffer_disable,
-	.data_available = iio_dma_buffer_data_available,
+	.data_available = iio_dma_buffer_usage,
+	.space_available = iio_dma_buffer_usage,
 	.release = iio_dmaengine_buffer_release,
 
 	.modes = INDIO_BUFFER_HARDWARE,
@@ -159,7 +172,7 @@ static const struct iio_dev_attr *iio_dmaengine_buffer_attrs[] = {
  * Once done using the buffer iio_dmaengine_buffer_free() should be used to
  * release it.
  */
-struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,
+static struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,
 	const char *channel)
 {
 	struct dmaengine_buffer *dmaengine_buffer;
@@ -210,7 +223,6 @@ err_free:
 	kfree(dmaengine_buffer);
 	return ERR_PTR(ret);
 }
-EXPORT_SYMBOL_NS_GPL(iio_dmaengine_buffer_alloc, IIO_DMAENGINE_BUFFER);
 
 /**
  * iio_dmaengine_buffer_free() - Free dmaengine buffer
@@ -230,66 +242,64 @@ void iio_dmaengine_buffer_free(struct iio_buffer *buffer)
 }
 EXPORT_SYMBOL_NS_GPL(iio_dmaengine_buffer_free, IIO_DMAENGINE_BUFFER);
 
-static void __devm_iio_dmaengine_buffer_free(void *buffer)
-{
-	iio_dmaengine_buffer_free(buffer);
-}
-
-/**
- * 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.
- */
-static struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
-	const char *channel)
+struct iio_buffer *iio_dmaengine_buffer_setup_ext(struct device *dev,
+						  struct iio_dev *indio_dev,
+						  const char *channel,
+						  enum iio_buffer_direction dir)
 {
 	struct iio_buffer *buffer;
 	int ret;
 
 	buffer = iio_dmaengine_buffer_alloc(dev, channel);
 	if (IS_ERR(buffer))
-		return buffer;
+		return ERR_CAST(buffer);
 
-	ret = devm_add_action_or_reset(dev, __devm_iio_dmaengine_buffer_free,
-				       buffer);
-	if (ret)
+	indio_dev->modes |= INDIO_BUFFER_HARDWARE;
+
+	buffer->direction = dir;
+
+	ret = iio_device_attach_buffer(indio_dev, buffer);
+	if (ret) {
+		iio_dmaengine_buffer_free(buffer);
 		return ERR_PTR(ret);
+	}
 
 	return buffer;
 }
+EXPORT_SYMBOL_NS_GPL(iio_dmaengine_buffer_setup_ext, IIO_DMAENGINE_BUFFER);
+
+static void __devm_iio_dmaengine_buffer_free(void *buffer)
+{
+	iio_dmaengine_buffer_free(buffer);
+}
 
 /**
- * devm_iio_dmaengine_buffer_setup() - Setup a DMA buffer for an IIO device
+ * devm_iio_dmaengine_buffer_setup_ext() - 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".
+ * @dir: Direction of buffer (in or out)
  *
  * 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)
+int devm_iio_dmaengine_buffer_setup_ext(struct device *dev,
+					struct iio_dev *indio_dev,
+					const char *channel,
+					enum iio_buffer_direction dir)
 {
 	struct iio_buffer *buffer;
 
-	buffer = devm_iio_dmaengine_buffer_alloc(dev, channel);
+	buffer = iio_dmaengine_buffer_setup_ext(dev, indio_dev, channel, dir);
 	if (IS_ERR(buffer))
 		return PTR_ERR(buffer);
 
-	indio_dev->modes |= INDIO_BUFFER_HARDWARE;
-
-	return iio_device_attach_buffer(indio_dev, buffer);
+	return devm_add_action_or_reset(dev, __devm_iio_dmaengine_buffer_free,
+					buffer);
 }
-EXPORT_SYMBOL_NS_GPL(devm_iio_dmaengine_buffer_setup, IIO_DMAENGINE_BUFFER);
+EXPORT_SYMBOL_NS_GPL(devm_iio_dmaengine_buffer_setup_ext, IIO_DMAENGINE_BUFFER);
 
 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 MODULE_DESCRIPTION("DMA buffer for the IIO framework");