Commit c1b91566 authored by Paul Cercueil's avatar Paul Cercueil Committed by Jonathan Cameron
Browse files

iio: buffer-dmaengine: Support specifying buffer direction 



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: default avatarPaul Cercueil <paul@crapouillou.net>
Reviewed-by: default avatarAlexandru Ardelean <ardeleanalex@gmail.com>
Signed-off-by: default avatarNuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240419-iio-backend-axi-dac-v4-4-5ca45b4de294@analog.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent fb09feba

drivers/iio/buffer/industrialio-buffer-dmaengine.c

+30 −14
Original line number Diff line number Diff line
@@ -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;
@@ -229,9 +240,10 @@ void iio_dmaengine_buffer_free(struct iio_buffer *buffer) 
}

EXPORT_SYMBOL_NS_GPL(iio_dmaengine_buffer_free, IIO_DMAENGINE_BUFFER);



struct iio_buffer *iio_dmaengine_buffer_setup(struct device *dev,

struct iio_buffer *iio_dmaengine_buffer_setup_ext(struct device *dev,

						  struct iio_dev *indio_dev,

					      const char *channel)

						  const char *channel,

						  enum iio_buffer_direction dir)

{

	struct iio_buffer *buffer;

	int ret;
@@ -242,6 +254,8 @@ struct iio_buffer *iio_dmaengine_buffer_setup(struct device *dev, 


	indio_dev->modes |= INDIO_BUFFER_HARDWARE;



	buffer->direction = dir;



	ret = iio_device_attach_buffer(indio_dev, buffer);

	if (ret) {

		iio_dmaengine_buffer_free(buffer);
@@ -250,7 +264,7 @@ struct iio_buffer *iio_dmaengine_buffer_setup(struct device *dev, 


	return buffer;

}

EXPORT_SYMBOL_NS_GPL(iio_dmaengine_buffer_setup, IIO_DMAENGINE_BUFFER);

EXPORT_SYMBOL_NS_GPL(iio_dmaengine_buffer_setup_ext, IIO_DMAENGINE_BUFFER);



static void __devm_iio_dmaengine_buffer_free(void *buffer)

{
@@ -258,30 +272,32 @@ static void __devm_iio_dmaengine_buffer_free(void *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,

int devm_iio_dmaengine_buffer_setup_ext(struct device *dev,

					struct iio_dev *indio_dev,

				    const char *channel)

					const char *channel,

					enum iio_buffer_direction dir)

{

	struct iio_buffer *buffer;



	buffer = iio_dmaengine_buffer_setup(dev, indio_dev, channel);

	buffer = iio_dmaengine_buffer_setup_ext(dev, indio_dev, channel, dir);

	if (IS_ERR(buffer))

		return PTR_ERR(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");

include/linux/iio/buffer-dmaengine.h

+19 −6
Original line number Diff line number Diff line
@@ -7,15 +7,28 @@ 
#ifndef __IIO_DMAENGINE_H__

#define __IIO_DMAENGINE_H__



#include <linux/iio/buffer.h>



struct iio_dev;

struct device;



void iio_dmaengine_buffer_free(struct iio_buffer *buffer);

struct iio_buffer *iio_dmaengine_buffer_setup(struct device *dev,

struct iio_buffer *iio_dmaengine_buffer_setup_ext(struct device *dev,

						  struct iio_dev *indio_dev,

					      const char *channel);

int devm_iio_dmaengine_buffer_setup(struct device *dev,

						  const char *channel,

						  enum iio_buffer_direction dir);



#define iio_dmaengine_buffer_setup(dev, indio_dev, channel)	\

	iio_dmaengine_buffer_setup_ext(dev, indio_dev, channel,	\

				       IIO_BUFFER_DIRECTION_IN)



int devm_iio_dmaengine_buffer_setup_ext(struct device *dev,

					struct iio_dev *indio_dev,

				    const char *channel);

					const char *channel,

					enum iio_buffer_direction dir);



#define devm_iio_dmaengine_buffer_setup(dev, indio_dev, channel)	\

	devm_iio_dmaengine_buffer_setup_ext(dev, indio_dev, channel,	\

					    IIO_BUFFER_DIRECTION_IN)



#endif