staging:iio:dummy: Register same channels for device and buffer

In preparation for moving the buffer registration to the core make sure to
register the same channel array for the device and the buffer. Currently the
output voltage and the activity channels are not registered for the buffer,
setting its scan index to -1 will make sure that it is skipped for the
buffer.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/iio_simple_dummy.c

@@ -239,6 +239,7 @@ static const struct iio_chan_spec iio_dummy_channels[] = {
 	{
 		.type = IIO_VOLTAGE,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.scan_index = -1, /* No buffer support */
 		.output = 1,
 		.indexed = 1,
 		.channel = 0,
@@ -248,7 +249,7 @@ static const struct iio_chan_spec iio_dummy_channels[] = {
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_ENABLE) |
 			BIT(IIO_CHAN_INFO_CALIBHEIGHT),
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
-		.scan_index = -1,
+		.scan_index = -1, /* No buffer support */
 #ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
 		.event_spec = &step_detect_event,
 		.num_event_specs = 1,
@@ -259,6 +260,7 @@ static const struct iio_chan_spec iio_dummy_channels[] = {
 		.modified = 1,
 		.channel2 = IIO_MOD_RUNNING,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.scan_index = -1, /* No buffer support */
 #ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
 		.event_spec = &iio_running_event,
 		.num_event_specs = 1,
@@ -269,6 +271,7 @@ static const struct iio_chan_spec iio_dummy_channels[] = {
 		.modified = 1,
 		.channel2 = IIO_MOD_WALKING,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.scan_index = -1, /* No buffer support */
 #ifdef CONFIG_IIO_SIMPLE_DUMMY_EVENTS
 		.event_spec = &iio_walking_event,
 		.num_event_specs = 1,
@@ -638,13 +641,7 @@ static int iio_dummy_probe(int index)
 	if (ret < 0)
 		goto error_free_device;
 
-	/*
-	 * Configure buffered capture support and register the channels with the
-	 * buffer, but avoid the output channel being registered by reducing the
-	 * number of channels by 1.
-	 */
-	ret = iio_simple_dummy_configure_buffer(indio_dev,
-						iio_dummy_channels, 5);
+	ret = iio_simple_dummy_configure_buffer(indio_dev);
 	if (ret < 0)
 		goto error_unregister_events;
 

drivers/staging/iio/iio_simple_dummy.h

@@ -114,8 +114,7 @@ enum iio_simple_dummy_scan_elements {
 };
 
 #ifdef CONFIG_IIO_SIMPLE_DUMMY_BUFFER
-int iio_simple_dummy_configure_buffer(struct iio_dev *indio_dev,
-	const struct iio_chan_spec *channels, unsigned int num_channels);
+int iio_simple_dummy_configure_buffer(struct iio_dev *indio_dev);
 void iio_simple_dummy_unconfigure_buffer(struct iio_dev *indio_dev);
 #else
 static inline int iio_simple_dummy_configure_buffer(struct iio_dev *indio_dev,

drivers/staging/iio/iio_simple_dummy_buffer.c

@@ -115,8 +115,7 @@ static const struct iio_buffer_setup_ops iio_simple_dummy_buffer_setup_ops = {
 	.predisable = &iio_triggered_buffer_predisable,
 };
 
-int iio_simple_dummy_configure_buffer(struct iio_dev *indio_dev,
-	const struct iio_chan_spec *channels, unsigned int num_channels)
+int iio_simple_dummy_configure_buffer(struct iio_dev *indio_dev)
 {
 	int ret;
 	struct iio_buffer *buffer;
@@ -173,7 +172,8 @@ int iio_simple_dummy_configure_buffer(struct iio_dev *indio_dev,
 	 */
 	indio_dev->modes |= INDIO_BUFFER_TRIGGERED;
 
-	ret = iio_buffer_register(indio_dev, channels, num_channels);
+	ret = iio_buffer_register(indio_dev, indio_dev->channels,
+				  indio_dev->num_channels);
 	if (ret)
 		goto error_dealloc_pollfunc;