[PATCH v3 4/6] iio: buffer-dma: Allow to provide custom buffer ops

From: Alexandru Ardelean
Date: Fri Feb 19 2021 - 07:41:30 EST


From: Lars-Peter Clausen <lars@xxxxxxxxxx>

Some devices that want to make use of the DMA buffer might need to do
something special, like write a register when the buffer is enabled.

Extend the API to allow those drivers to provide their own buffer ops.

Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
---
drivers/iio/adc/adi-axi-adc.c | 3 ++-
drivers/iio/buffer/industrialio-buffer-dma.c | 4 +++-
.../buffer/industrialio-buffer-dmaengine.c | 23 +++++++++++++------
include/linux/iio/buffer-dma.h | 5 +++-
include/linux/iio/buffer-dmaengine.h | 6 +++--
5 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index 2e84623f732e..bfa00100a631 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -113,7 +113,8 @@ 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,
+ NULL, NULL);
}

static int adi_axi_adc_read_raw(struct iio_dev *indio_dev,
diff --git a/drivers/iio/buffer/industrialio-buffer-dma.c b/drivers/iio/buffer/industrialio-buffer-dma.c
index 1ae47ed8ef22..aa56c10418d0 100644
--- a/drivers/iio/buffer/industrialio-buffer-dma.c
+++ b/drivers/iio/buffer/industrialio-buffer-dma.c
@@ -892,13 +892,15 @@ EXPORT_SYMBOL_GPL(iio_dma_buffer_set_length);
* allocations are done from a memory region that can be accessed by the device.
*/
int iio_dma_buffer_init(struct iio_dma_buffer_queue *queue,
- struct device *dev, const struct iio_dma_buffer_ops *ops)
+ struct device *dev, const struct iio_dma_buffer_ops *ops,
+ void *driver_data)
{
iio_buffer_init(&queue->buffer);
queue->buffer.length = PAGE_SIZE;
queue->buffer.watermark = queue->buffer.length / 2;
queue->dev = dev;
queue->ops = ops;
+ queue->driver_data = driver_data;

INIT_LIST_HEAD(&queue->incoming);
INIT_LIST_HEAD(&queue->outgoing);
diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index 6db24be7e11d..a4e7b97ce239 100644
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
@@ -163,6 +163,8 @@ static const struct attribute *iio_dmaengine_buffer_attrs[] = {
* iio_dmaengine_buffer_alloc() - Allocate new buffer which uses DMAengine
* @dev: Parent device for the buffer
* @channel: DMA channel name, typically "rx".
+ * @ops: Custom iio_dma_buffer_ops, if NULL default ops will be used
+ * @driver_data: Driver data to be passed to custom iio_dma_buffer_ops
*
* 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
@@ -172,7 +174,8 @@ static const struct attribute *iio_dmaengine_buffer_attrs[] = {
* release it.
*/
static struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,
- const char *channel)
+ const char *channel, const struct iio_dma_buffer_ops *ops,
+ void *driver_data)
{
struct dmaengine_buffer *dmaengine_buffer;
unsigned int width, src_width, dest_width;
@@ -211,7 +214,7 @@ static struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,
dmaengine_buffer->max_size = dma_get_max_seg_size(chan->device->dev);

iio_dma_buffer_init(&dmaengine_buffer->queue, chan->device->dev,
- &iio_dmaengine_default_ops);
+ ops ? ops : &iio_dmaengine_default_ops, driver_data);

dmaengine_buffer->queue.buffer.attrs = iio_dmaengine_buffer_attrs;
dmaengine_buffer->queue.buffer.access = &iio_dmaengine_buffer_ops;
@@ -249,6 +252,8 @@ static void __devm_iio_dmaengine_buffer_free(struct device *dev, void *res)
* devm_iio_dmaengine_buffer_alloc() - Resource-managed iio_dmaengine_buffer_alloc()
* @dev: Parent device for the buffer
* @channel: DMA channel name, typically "rx".
+ * @ops: Custom iio_dma_buffer_ops, if NULL default ops will be used
+ * @driver_data: Driver data to be passed to custom iio_dma_buffer_ops
*
* 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
@@ -257,7 +262,8 @@ static void __devm_iio_dmaengine_buffer_free(struct device *dev, void *res)
* 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)
+ const char *channel, const struct iio_dma_buffer_ops *ops,
+ void *driver_data)
{
struct iio_buffer **bufferp, *buffer;

@@ -266,7 +272,7 @@ static struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
if (!bufferp)
return ERR_PTR(-ENOMEM);

- buffer = iio_dmaengine_buffer_alloc(dev, channel);
+ buffer = iio_dmaengine_buffer_alloc(dev, channel, ops, driver_data);
if (IS_ERR(buffer)) {
devres_free(bufferp);
return buffer;
@@ -283,6 +289,8 @@ static struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
* @dev: Parent device for the buffer
* @indio_dev: IIO device to which to attach this buffer.
* @channel: DMA channel name, typically "rx".
+ * @ops: Custom iio_dma_buffer_ops, if NULL default ops will be used
+ * @driver_data: Driver data to be passed to custom iio_dma_buffer_ops
*
* This allocates a new IIO buffer with devm_iio_dmaengine_buffer_alloc()
* and attaches it to an IIO device with iio_device_attach_buffer().
@@ -290,13 +298,14 @@ static struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
* IIO device.
*/
int devm_iio_dmaengine_buffer_setup(struct device *dev,
- struct iio_dev *indio_dev,
- const char *channel)
+ struct iio_dev *indio_dev, const char *channel,
+ const struct iio_dma_buffer_ops *ops,
+ void *driver_data)
{
struct iio_buffer *buffer;

buffer = devm_iio_dmaengine_buffer_alloc(indio_dev->dev.parent,
- channel);
+ channel, ops, driver_data);
if (IS_ERR(buffer))
return PTR_ERR(buffer);

diff --git a/include/linux/iio/buffer-dma.h b/include/linux/iio/buffer-dma.h
index f6f2ce3e2ed1..1eec7efe44cf 100644
--- a/include/linux/iio/buffer-dma.h
+++ b/include/linux/iio/buffer-dma.h
@@ -110,6 +110,8 @@ struct iio_dma_buffer_queue {

bool active;

+ void *driver_data;
+
unsigned int num_blocks;
struct iio_dma_buffer_block **blocks;
unsigned int max_offset;
@@ -144,7 +146,8 @@ int iio_dma_buffer_set_length(struct iio_buffer *buffer, unsigned int length);
int iio_dma_buffer_request_update(struct iio_buffer *buffer);

int iio_dma_buffer_init(struct iio_dma_buffer_queue *queue,
- struct device *dma_dev, const struct iio_dma_buffer_ops *ops);
+ struct device *dma_dev, const struct iio_dma_buffer_ops *ops,
+ void *driver_data);
void iio_dma_buffer_exit(struct iio_dma_buffer_queue *queue);
void iio_dma_buffer_release(struct iio_dma_buffer_queue *queue);

diff --git a/include/linux/iio/buffer-dmaengine.h b/include/linux/iio/buffer-dmaengine.h
index 5c355be89814..1fca8cdbf14e 100644
--- a/include/linux/iio/buffer-dmaengine.h
+++ b/include/linux/iio/buffer-dmaengine.h
@@ -8,10 +8,12 @@
#define __IIO_DMAENGINE_H__

struct iio_dev;
+struct iio_dma_buffer_ops;
struct device;

int devm_iio_dmaengine_buffer_setup(struct device *dev,
- struct iio_dev *indio_dev,
- const char *channel);
+ struct iio_dev *indio_dev, const char *channel,
+ const struct iio_dma_buffer_ops *ops,
+ void *driver_data);

#endif
--
2.27.0