For buffered mode we do not want to perform endianness conversion in the kernel,
but rather offload it to user space, since it is not always required to do a
conversion at all. It also greatly simplifies the kernel code since no
post-processing has to be done and may allow future optimizations like streaming
data directly to a storage device or over the network via DMA.
Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
---
drivers/staging/iio/adc/ad7298.h | 2 +-
drivers/staging/iio/adc/ad7298_core.c | 1 +
drivers/staging/iio/adc/ad7298_ring.c | 11 +++--------
3 files changed, 5 insertions(+), 9 deletions(-)
diff --git a/drivers/staging/iio/adc/ad7298.h b/drivers/staging/iio/adc/ad7298.h
index 18f2787..0ce9031 100644
--- a/drivers/staging/iio/adc/ad7298.h
+++ b/drivers/staging/iio/adc/ad7298.h
@@ -48,7 +48,7 @@ struct ad7298_state {
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
- unsigned short rx_buf[8] ____cacheline_aligned;
+ unsigned short rx_buf[12] ____cacheline_aligned;
unsigned short tx_buf[2];
};
diff --git a/drivers/staging/iio/adc/ad7298_core.c b/drivers/staging/iio/adc/ad7298_core.c
index 4c75114..67082ad 100644
--- a/drivers/staging/iio/adc/ad7298_core.c
+++ b/drivers/staging/iio/adc/ad7298_core.c
@@ -35,6 +35,7 @@
.sign = 'u', \
.realbits = 12, \
.storagebits = 16, \
+ .endianness = IIO_BE, \
}, \
}
diff --git a/drivers/staging/iio/adc/ad7298_ring.c b/drivers/staging/iio/adc/ad7298_ring.c
index b3dd514..e387712 100644
--- a/drivers/staging/iio/adc/ad7298_ring.c
+++ b/drivers/staging/iio/adc/ad7298_ring.c
@@ -76,8 +76,7 @@ static irqreturn_t ad7298_trigger_handler(int irq, void *p)
struct iio_dev *indio_dev = pf->indio_dev;
struct ad7298_state *st = iio_priv(indio_dev);
s64 time_ns = 0;
- __u16 buf[16];
- int b_sent, i;
+ int b_sent;
b_sent = spi_sync(st->spi, &st->ring_msg);
if (b_sent)
@@ -85,15 +84,11 @@ static irqreturn_t ad7298_trigger_handler(int irq, void *p)
if (indio_dev->scan_timestamp) {
time_ns = iio_get_time_ns();
- memcpy((u8 *)buf + indio_dev->scan_bytes - sizeof(s64),
+ memcpy((u8 *)st->rx_buf + indio_dev->scan_bytes - sizeof(s64),
&time_ns, sizeof(time_ns));
}
- for (i = 0; i < bitmap_weight(indio_dev->active_scan_mask,
- indio_dev->masklength); i++)
- buf[i] = be16_to_cpu(st->rx_buf[i]);
-
- iio_push_to_buffers(indio_dev, (u8 *)buf);
+ iio_push_to_buffers(indio_dev, (u8 *)st->rx_buf);
done:
iio_trigger_notify_done(indio_dev->trig);
--
1.8.0
--
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