staging:iio:adc:ad7476 scrap read from buffer for sysfs access.

No known use case and complicates in kernel interface work.
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/adc/ad7298.h

@@ -54,14 +54,9 @@ struct ad7298_state {
 };
 
 #ifdef CONFIG_IIO_BUFFER
-int ad7298_scan_from_ring(struct iio_dev *indio_dev, long ch);
 int ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev);
 void ad7298_ring_cleanup(struct iio_dev *indio_dev);
 #else /* CONFIG_IIO_BUFFER */
-static inline int ad7298_scan_from_ring(struct iio_dev *indio_dev, long ch)
-{
-	return 0;
-}
 
 static inline int
 ad7298_register_ring_funcs_and_init(struct iio_dev *indio_dev)

drivers/staging/iio/adc/ad7298_core.c

@@ -123,12 +123,8 @@ static int ad7298_read_raw(struct iio_dev *indio_dev,
 	switch (m) {
 	case 0:
 		mutex_lock(&indio_dev->mlock);
-		if (iio_buffer_enabled(indio_dev)) {
-			if (chan->address == AD7298_CH_TEMP)
-				ret = -ENODEV;
-			else
-				ret = ad7298_scan_from_ring(indio_dev,
-							    chan->address);
+		if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
+			ret = -EBUSY;
 		} else {
 			if (chan->address == AD7298_CH_TEMP)
 				ret = ad7298_scan_temp(st, val);

drivers/staging/iio/adc/ad7298_ring.c

@@ -18,35 +18,6 @@
 
 #include "ad7298.h"
 
-int ad7298_scan_from_ring(struct iio_dev *indio_dev, long ch)
-{
-	struct iio_buffer *ring = indio_dev->buffer;
-	int ret;
-	u16 *ring_data;
-
-	if (!(test_bit(ch, ring->scan_mask))) {
-		ret = -EBUSY;
-		goto error_ret;
-	}
-
-	ring_data = kmalloc(ring->access->get_bytes_per_datum(ring),
-			    GFP_KERNEL);
-	if (ring_data == NULL) {
-		ret = -ENOMEM;
-		goto error_ret;
-	}
-	ret = ring->access->read_last(ring, (u8 *) ring_data);
-	if (ret)
-		goto error_free_ring_data;
-
-	ret = be16_to_cpu(ring_data[ch]);
-
-error_free_ring_data:
-	kfree(ring_data);
-error_ret:
-	return ret;
-}
-
 /**
  * ad7298_ring_preenable() setup the parameters of the ring before enabling
  *