iio: triggered-buffer: extend support to configure output buffers

Now that output (kfifo) buffers are supported, we need to extend the
{devm_}iio_triggered_buffer_setup_ext() parameter list to take a direction
parameter.

This allows us to attach an output triggered buffer to a DAC device.
Unfortunately it's a bit difficult to add another macro to avoid changing 5
drivers where {devm_}iio_triggered_buffer_setup_ext() is used.
Well, it's doable, but may not be worth the trouble vs just updating all
these 5 drivers.

Signed-off-by: Alexandru Ardelean <[e-mail]>
Signed-off-by: Mihail Chindris <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/accel/adxl372.c

···
 	ret = devm_iio_triggered_buffer_setup_ext(dev,
 						  indio_dev, NULL,
 						  adxl372_trigger_handler,
+						  IIO_BUFFER_DIRECTION_IN,
 						  &adxl372_buffer_ops,
 						  adxl372_fifo_attributes);
 	if (ret < 0)

drivers/iio/accel/bmc150-accel-core.c

···
 	ret = iio_triggered_buffer_setup_ext(indio_dev,
 					     &iio_pollfunc_store_time,
 					     bmc150_accel_trigger_handler,
+					     IIO_BUFFER_DIRECTION_IN,
 					     &bmc150_accel_buffer_ops,
 					     fifo_attrs);
 	if (ret < 0) {

drivers/iio/adc/at91-sama5d2_adc.c

···
 		fifo_attrs = NULL;
 
 	ret = devm_iio_triggered_buffer_setup_ext(&indio->dev, indio,
-		&iio_pollfunc_store_time,
-		&at91_adc_trigger_handler, &at91_buffer_setup_ops, fifo_attrs);
+		&iio_pollfunc_store_time, &at91_adc_trigger_handler,
+		IIO_BUFFER_DIRECTION_IN, &at91_buffer_setup_ops, fifo_attrs);
 	if (ret < 0) {
 		dev_err(dev, "couldn't initialize the buffer.\n");
 		return ret;

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

···
  * @indio_dev:		IIO device structure
  * @h:			Function which will be used as pollfunc top half
  * @thread:		Function which will be used as pollfunc bottom half
+ * @direction:		Direction of the data stream (in/out).
  * @setup_ops:		Buffer setup functions to use for this device.
  *			If NULL the default setup functions for triggered
  *			buffers will be used.
···
 int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev,
 	irqreturn_t (*h)(int irq, void *p),
 	irqreturn_t (*thread)(int irq, void *p),
+	enum iio_buffer_direction direction,
 	const struct iio_buffer_setup_ops *setup_ops,
 	const struct attribute **buffer_attrs)
 {
···
 	/* Flag that polled ring buffering is possible */
 	indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
 
+	buffer->direction = direction;
 	buffer->attrs = buffer_attrs;
 
 	ret = iio_device_attach_buffer(indio_dev, buffer);
···
 					struct iio_dev *indio_dev,
 					irqreturn_t (*h)(int irq, void *p),
 					irqreturn_t (*thread)(int irq, void *p),
+					enum iio_buffer_direction direction,
 					const struct iio_buffer_setup_ops *ops,
 					const struct attribute **buffer_attrs)
 {
 	int ret;
 
-	ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, ops,
-					     buffer_attrs);
+	ret = iio_triggered_buffer_setup_ext(indio_dev, h, thread, direction,
+					     ops, buffer_attrs);
 	if (ret)
 		return ret;
 

drivers/iio/common/hid-sensors/hid-sensor-trigger.c

···
 		fifo_attrs = NULL;
 
 	ret = iio_triggered_buffer_setup_ext(indio_dev,
-					     &iio_pollfunc_store_time,
-					     NULL, NULL, fifo_attrs);
+					     &iio_pollfunc_store_time, NULL,
+					     IIO_BUFFER_DIRECTION_IN,
+					     NULL, fifo_attrs);
 	if (ret) {
 		dev_err(&indio_dev->dev, "Triggered Buffer Setup Failed\n");
 		return ret;

include/linux/iio/triggered_buffer.h

···
 #ifndef _LINUX_IIO_TRIGGERED_BUFFER_H_
 #define _LINUX_IIO_TRIGGERED_BUFFER_H_
 
+#include <linux/iio/buffer.h>
 #include <linux/interrupt.h>
 
 struct attribute;
···
 int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev,
 	irqreturn_t (*h)(int irq, void *p),
 	irqreturn_t (*thread)(int irq, void *p),
+	enum iio_buffer_direction direction,
 	const struct iio_buffer_setup_ops *setup_ops,
 	const struct attribute **buffer_attrs);
 void iio_triggered_buffer_cleanup(struct iio_dev *indio_dev);
 
 #define iio_triggered_buffer_setup(indio_dev, h, thread, setup_ops)		\
-	iio_triggered_buffer_setup_ext((indio_dev), (h), (thread), (setup_ops), NULL)
+	iio_triggered_buffer_setup_ext((indio_dev), (h), (thread),		\
+					IIO_BUFFER_DIRECTION_IN, (setup_ops),	\
+					NULL)
 
 int devm_iio_triggered_buffer_setup_ext(struct device *dev,
 					struct iio_dev *indio_dev,
 					irqreturn_t (*h)(int irq, void *p),
 					irqreturn_t (*thread)(int irq, void *p),
+					enum iio_buffer_direction direction,
 					const struct iio_buffer_setup_ops *ops,
 					const struct attribute **buffer_attrs);
 
 #define devm_iio_triggered_buffer_setup(dev, indio_dev, h, thread, setup_ops)	\
-	devm_iio_triggered_buffer_setup_ext((dev), (indio_dev), (h), (thread), (setup_ops), NULL)
+	devm_iio_triggered_buffer_setup_ext((dev), (indio_dev), (h), (thread),	\
+					    IIO_BUFFER_DIRECTION_IN,		\
+					    (setup_ops), NULL)
 
 #endif