diff mbox series

[v3,05/11] iio: buffer-dmaengine: Support specifying buffer direction

Message ID 20230403154800.215924-6-paul@crapouillou.net (mailing list archive)
State Handled Elsewhere
Headers show
Series iio: new DMABUF based API, v3 | expand

Commit Message

Paul Cercueil April 3, 2023, 3:47 p.m. UTC 
Update the devm_iio_dmaengine_buffer_setup() function to support
specifying the buffer direction.

Update the iio_dmaengine_buffer_submit() function to handle input
buffers as well as output buffers.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
---
 drivers/iio/adc/adi-axi-adc.c                 |  3 ++-
 .../buffer/industrialio-buffer-dmaengine.c    | 24 +++++++++++++++----
 include/linux/iio/buffer-dmaengine.h          |  5 +++-
 3 files changed, 25 insertions(+), 7 deletions(-)

Comments

Jonathan Cameron April 16, 2023, 2:35 p.m. UTC | #1 
On Mon,  3 Apr 2023 17:47:54 +0200
Paul Cercueil <paul@crapouillou.net> wrote:

> Update the devm_iio_dmaengine_buffer_setup() function to support
> specifying the buffer direction.
> 
> Update the iio_dmaengine_buffer_submit() function to handle input
> buffers as well as output buffers.
> 
> Signed-off-by: Paul Cercueil <paul@crapouillou.net>
> Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>

Just one trivial question inline.

Jonathan

> diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
> index 5f85ba38e6f6..592d2aa9044c 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;

Two paths to here.  Either DIRECTION_IN in which we just set things
up so conditions being checked are always fine (unless max_size == 0?
Can that happen?), or !DIRECTION_IN.
So why not move this into the else {} branch above?

>  
>  	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;
diff mbox series

Patch

diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index e8a8ea4140f1..d33574b5417a 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -114,7 +114,8 @@  static int adi_axi_adc_config_dma_buffer(struct device *dev,
 		dma_name = "rx";
 
 	return devm_iio_dmaengine_buffer_setup(indio_dev->dev.parent,
-					       indio_dev, dma_name);
+					       indio_dev, dma_name,
+					       IIO_BUFFER_DIRECTION_IN);
 }
 
 static int adi_axi_adc_read_raw(struct iio_dev *indio_dev,
diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index 5f85ba38e6f6..592d2aa9044c 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;
@@ -275,7 +286,8 @@  static struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
  */
 int devm_iio_dmaengine_buffer_setup(struct device *dev,
 				    struct iio_dev *indio_dev,
-				    const char *channel)
+				    const char *channel,
+				    enum iio_buffer_direction dir)
 {
 	struct iio_buffer *buffer;
 
@@ -286,6 +298,8 @@  int devm_iio_dmaengine_buffer_setup(struct device *dev,
 
 	indio_dev->modes |= INDIO_BUFFER_HARDWARE;
 
+	buffer->direction = dir;
+
 	return iio_device_attach_buffer(indio_dev, buffer);
 }
 EXPORT_SYMBOL_GPL(devm_iio_dmaengine_buffer_setup);
diff --git a/include/linux/iio/buffer-dmaengine.h b/include/linux/iio/buffer-dmaengine.h
index 5c355be89814..538d0479cdd6 100644
--- a/include/linux/iio/buffer-dmaengine.h
+++ b/include/linux/iio/buffer-dmaengine.h
@@ -7,11 +7,14 @@ 
 #ifndef __IIO_DMAENGINE_H__
 #define __IIO_DMAENGINE_H__
 
+#include <linux/iio/buffer.h>
+
 struct iio_dev;
 struct device;
 
 int devm_iio_dmaengine_buffer_setup(struct device *dev,
 				    struct iio_dev *indio_dev,
-				    const char *channel);
+				    const char *channel,
+				    enum iio_buffer_direction dir);
 
 #endif