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authorLars-Peter Clausen <lars@metafoo.de>2012-11-15 08:15:00 -0500
committerJonathan Cameron <jic23@kernel.org>2012-11-19 17:22:13 -0500
commitca654638f2b4b00f948d2126dd544d2e35d2b880 (patch)
treecde708b2dc163e3bcb61a33a234895605738f458 /drivers
parentec04cb048d79cd778c06e28f34395a46d774800d (diff)
staging:iio:ad7298: Do not perform endianness conversion in buffered mode
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@metafoo.de> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/staging/iio/adc/ad7298.h2
-rw-r--r--drivers/staging/iio/adc/ad7298_core.c1
-rw-r--r--drivers/staging/iio/adc/ad7298_ring.c11
3 files changed, 5 insertions, 9 deletions
diff --git a/drivers/staging/iio/adc/ad7298.h b/drivers/staging/iio/adc/ad7298.h
index 18f27872300..0ce9031bec9 100644
--- a/drivers/staging/iio/adc/ad7298.h
+++ b/drivers/staging/iio/adc/ad7298.h
@@ -48,7 +48,7 @@ struct ad7298_state {
48 * DMA (thus cache coherency maintenance) requires the 48 * DMA (thus cache coherency maintenance) requires the
49 * transfer buffers to live in their own cache lines. 49 * transfer buffers to live in their own cache lines.
50 */ 50 */
51 unsigned short rx_buf[8] ____cacheline_aligned; 51 unsigned short rx_buf[12] ____cacheline_aligned;
52 unsigned short tx_buf[2]; 52 unsigned short tx_buf[2];
53}; 53};
54 54
diff --git a/drivers/staging/iio/adc/ad7298_core.c b/drivers/staging/iio/adc/ad7298_core.c
index 4c75114e7d7..67082ade185 100644
--- a/drivers/staging/iio/adc/ad7298_core.c
+++ b/drivers/staging/iio/adc/ad7298_core.c
@@ -35,6 +35,7 @@
35 .sign = 'u', \ 35 .sign = 'u', \
36 .realbits = 12, \ 36 .realbits = 12, \
37 .storagebits = 16, \ 37 .storagebits = 16, \
38 .endianness = IIO_BE, \
38 }, \ 39 }, \
39 } 40 }
40 41
diff --git a/drivers/staging/iio/adc/ad7298_ring.c b/drivers/staging/iio/adc/ad7298_ring.c
index b3dd514b962..e3877129222 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)
76 struct iio_dev *indio_dev = pf->indio_dev; 76 struct iio_dev *indio_dev = pf->indio_dev;
77 struct ad7298_state *st = iio_priv(indio_dev); 77 struct ad7298_state *st = iio_priv(indio_dev);
78 s64 time_ns = 0; 78 s64 time_ns = 0;
79 __u16 buf[16]; 79 int b_sent;
80 int b_sent, i;
81 80
82 b_sent = spi_sync(st->spi, &st->ring_msg); 81 b_sent = spi_sync(st->spi, &st->ring_msg);
83 if (b_sent) 82 if (b_sent)
@@ -85,15 +84,11 @@ static irqreturn_t ad7298_trigger_handler(int irq, void *p)
85 84
86 if (indio_dev->scan_timestamp) { 85 if (indio_dev->scan_timestamp) {
87 time_ns = iio_get_time_ns(); 86 time_ns = iio_get_time_ns();
88 memcpy((u8 *)buf + indio_dev->scan_bytes - sizeof(s64), 87 memcpy((u8 *)st->rx_buf + indio_dev->scan_bytes - sizeof(s64),
89 &time_ns, sizeof(time_ns)); 88 &time_ns, sizeof(time_ns));
90 } 89 }
91 90
92 for (i = 0; i < bitmap_weight(indio_dev->active_scan_mask, 91 iio_push_to_buffers(indio_dev, (u8 *)st->rx_buf);
93 indio_dev->masklength); i++)
94 buf[i] = be16_to_cpu(st->rx_buf[i]);
95
96 iio_push_to_buffers(indio_dev, (u8 *)buf);
97 92
98done: 93done:
99 iio_trigger_notify_done(indio_dev->trig); 94 iio_trigger_notify_done(indio_dev->trig);