[PATCH v6 06/24] iio: buffer-dma,adi-axi-adc: introduce devm_iio_dmaengine_buffer_setup()

From: Alexandru Ardelean
Date: Mon Feb 15 2021 - 05:42:07 EST


This change does a conversion of the devm_iio_dmaengine_buffer_alloc() to
devm_iio_dmaengine_buffer_setup(). This will allocate an IIO DMA buffer and
attach it to the IIO device, similar to devm_iio_triggered_buffer_setup()
(though the underlying code is different, the final logic is the same).

Since the only user of the devm_iio_dmaengine_buffer_alloc() was the
adi-axi-adc driver, this change does the replacement in a single go in the
driver.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
---
.../driver-api/driver-model/devres.rst | 1 +
drivers/iio/adc/adi-axi-adc.c | 12 ++-----
.../buffer/industrialio-buffer-dmaengine.c | 33 +++++++++++++++++--
include/linux/iio/buffer-dmaengine.h | 7 ++--
4 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst
index 4b15b3e9358b..5f8c6c303ff2 100644
--- a/Documentation/driver-api/driver-model/devres.rst
+++ b/Documentation/driver-api/driver-model/devres.rst
@@ -285,6 +285,7 @@ I2C
IIO
devm_iio_device_alloc()
devm_iio_device_register()
+ devm_iio_dmaengine_buffer_setup()
devm_iio_kfifo_buffer_setup()
devm_iio_triggered_buffer_setup()
devm_iio_trigger_alloc()
diff --git a/drivers/iio/adc/adi-axi-adc.c b/drivers/iio/adc/adi-axi-adc.c
index 9109da2d2e15..2e84623f732e 100644
--- a/drivers/iio/adc/adi-axi-adc.c
+++ b/drivers/iio/adc/adi-axi-adc.c
@@ -104,7 +104,6 @@ static unsigned int adi_axi_adc_read(struct adi_axi_adc_state *st,
static int adi_axi_adc_config_dma_buffer(struct device *dev,
struct iio_dev *indio_dev)
{
- struct iio_buffer *buffer;
const char *dma_name;

if (!device_property_present(dev, "dmas"))
@@ -113,15 +112,8 @@ static int adi_axi_adc_config_dma_buffer(struct device *dev,
if (device_property_read_string(dev, "dma-names", &dma_name))
dma_name = "rx";

- buffer = devm_iio_dmaengine_buffer_alloc(indio_dev->dev.parent,
- dma_name);
- if (IS_ERR(buffer))
- return PTR_ERR(buffer);
-
- indio_dev->modes |= INDIO_BUFFER_HARDWARE;
- iio_device_attach_buffer(indio_dev, buffer);
-
- return 0;
+ return devm_iio_dmaengine_buffer_setup(indio_dev->dev.parent,
+ indio_dev, dma_name);
}

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 b0cb9a35f5cd..9981896e1495 100644
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
@@ -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 +265,36 @@ 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;
+
+ iio_device_attach_buffer(indio_dev, buffer);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devm_iio_dmaengine_buffer_setup);

MODULE_AUTHOR("Lars-Peter Clausen <lars@xxxxxxxxxx>");
MODULE_DESCRIPTION("DMA buffer for the IIO framework");
diff --git a/include/linux/iio/buffer-dmaengine.h b/include/linux/iio/buffer-dmaengine.h
index 5b502291d6a4..5c355be89814 100644
--- a/include/linux/iio/buffer-dmaengine.h
+++ b/include/linux/iio/buffer-dmaengine.h
@@ -7,10 +7,11 @@
#ifndef __IIO_DMAENGINE_H__
#define __IIO_DMAENGINE_H__

-struct iio_buffer;
+struct iio_dev;
struct device;

-struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
- const char *channel);
+int devm_iio_dmaengine_buffer_setup(struct device *dev,
+ struct iio_dev *indio_dev,
+ const char *channel);

#endif
--
2.17.1