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authorPaul Cercueil <paul.cercueil@analog.com>2015-05-15 18:18:37 +0300
committerJonathan Cameron <jic23@kernel.org>2015-05-16 13:00:50 +0300
commit9df560350c90f3d3909fe653399b3584c9a17b61 (patch)
tree1cbb294399294c3ef35dbd44a4059c6dde2e7165
parentc2a8b623a089d52c199e305e7905829907db8ec8 (diff)
downloadlinux-9df560350c90f3d3909fe653399b3584c9a17b61.tar.xz
iio: adis16400: Fix burst mode
There are a few issues with the burst mode support. For one we don't setup the rx buffer, so the buffer will never be filled and all samples will read as the zero. Furthermore the tx buffer has the wrong type, which means the driver sends the wrong command and not the right data is returned. The final issue is that in burst mode all channels are transferred. Hence the length of the transfer length should be the number of hardware channels * 2 bytes. Currently the driver uses indio_dev->scan_bytes for this. But if the timestamp channel is enabled the scan_bytes will be larger than the burst length. Fix this by just calculating the burst length based on the number of hardware channels. Signed-off-by: Paul Cercueil <paul.cercueil@analog.com> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Fixes: 5eda3550a3cc ("staging:iio:adis16400: Preallocate transfer message") Cc: <stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
-rw-r--r--drivers/iio/imu/adis16400_buffer.c16
1 files changed, 9 insertions, 7 deletions
diff --git a/drivers/iio/imu/adis16400_buffer.c b/drivers/iio/imu/adis16400_buffer.c
index 6e727ffe5262..629ae84d4e62 100644
--- a/drivers/iio/imu/adis16400_buffer.c
+++ b/drivers/iio/imu/adis16400_buffer.c
@@ -18,7 +18,8 @@ int adis16400_update_scan_mode(struct iio_dev *indio_dev,
{
struct adis16400_state *st = iio_priv(indio_dev);
struct adis *adis = &st->adis;
- uint16_t *tx;
+ unsigned int burst_length;
+ u8 *tx;
if (st->variant->flags & ADIS16400_NO_BURST)
return adis_update_scan_mode(indio_dev, scan_mask);
@@ -26,26 +27,27 @@ int adis16400_update_scan_mode(struct iio_dev *indio_dev,
kfree(adis->xfer);
kfree(adis->buffer);
+ /* All but the timestamp channel */
+ burst_length = (indio_dev->num_channels - 1) * sizeof(u16);
+
adis->xfer = kcalloc(2, sizeof(*adis->xfer), GFP_KERNEL);
if (!adis->xfer)
return -ENOMEM;
- adis->buffer = kzalloc(indio_dev->scan_bytes + sizeof(u16),
- GFP_KERNEL);
+ adis->buffer = kzalloc(burst_length + sizeof(u16), GFP_KERNEL);
if (!adis->buffer)
return -ENOMEM;
- tx = adis->buffer + indio_dev->scan_bytes;
-
+ tx = adis->buffer + burst_length;
tx[0] = ADIS_READ_REG(ADIS16400_GLOB_CMD);
tx[1] = 0;
adis->xfer[0].tx_buf = tx;
adis->xfer[0].bits_per_word = 8;
adis->xfer[0].len = 2;
- adis->xfer[1].tx_buf = tx;
+ adis->xfer[1].rx_buf = adis->buffer;
adis->xfer[1].bits_per_word = 8;
- adis->xfer[1].len = indio_dev->scan_bytes;
+ adis->xfer[1].len = burst_length;
spi_message_init(&adis->msg);
spi_message_add_tail(&adis->xfer[0], &adis->msg);