iio: adis16400: Fix burst transfer for adis16448

The adis16448, unlike the other chips in this family, in addition to the
hardware channels also sends out the DIAG_STAT register in burst mode
before them. Handle that case by skipping over the first 2 bytes before we
pass the received data to the buffer.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Fixes: 76ada52f7f5d ("iio:adis16400: Add support for the adis16448")
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 12 insertions, 2 deletions

diff --git a/drivers/iio/imu/adis16400.h b/drivers/iio/imu/adis16400.h
index 1e8fd2e81d45..73b189c1c0fb 100644
--- a/drivers/iio/imu/adis16400.h
+++ b/drivers/iio/imu/adis16400.h
@@ -139,6 +139,7 @@
 #define ADIS16400_NO_BURST              BIT(1)
 #define ADIS16400_HAS_SLOW_MODE         BIT(2)
 #define ADIS16400_HAS_SERIAL_NUMBER     BIT(3)
+#define ADIS16400_BURST_DIAG_STAT       BIT(4)
 
 struct adis16400_state;
 
diff --git a/drivers/iio/imu/adis16400_buffer.c b/drivers/iio/imu/adis16400_buffer.c
index 629ae84d4e62..90c24a23c679 100644
--- a/drivers/iio/imu/adis16400_buffer.c
+++ b/drivers/iio/imu/adis16400_buffer.c
@@ -29,6 +29,8 @@ int adis16400_update_scan_mode(struct iio_dev *indio_dev,
 
         /* All but the timestamp channel */
         burst_length = (indio_dev->num_channels - 1) * sizeof(u16);
+        if (st->variant->flags & ADIS16400_BURST_DIAG_STAT)
+                burst_length += sizeof(u16);
 
         adis->xfer = kcalloc(2, sizeof(*adis->xfer), GFP_KERNEL);
         if (!adis->xfer)
@@ -63,6 +65,7 @@ irqreturn_t adis16400_trigger_handler(int irq, void *p)
         struct adis16400_state *st = iio_priv(indio_dev);
         struct adis *adis = &st->adis;
         u32 old_speed_hz = st->adis.spi->max_speed_hz;
+        void *buffer;
         int ret;
 
         if (!adis->buffer)
@@ -83,7 +86,12 @@ irqreturn_t adis16400_trigger_handler(int irq, void *p)
                 spi_setup(st->adis.spi);
         }
 
-        iio_push_to_buffers_with_timestamp(indio_dev, adis->buffer,
+        if (st->variant->flags & ADIS16400_BURST_DIAG_STAT)
+                buffer = adis->buffer + sizeof(u16);
+        else
+                buffer = adis->buffer;
+
+        iio_push_to_buffers_with_timestamp(indio_dev, buffer,
                 pf->timestamp);
 
         iio_trigger_notify_done(indio_dev->trig);
diff --git a/drivers/iio/imu/adis16400_core.c b/drivers/iio/imu/adis16400_core.c
index 7b06e058b000..2fd68f2219a7 100644
--- a/drivers/iio/imu/adis16400_core.c
+++ b/drivers/iio/imu/adis16400_core.c
@@ -778,7 +778,8 @@ static struct adis16400_chip_info adis16400_chips[] = {
                 .channels = adis16448_channels,
                 .num_channels = ARRAY_SIZE(adis16448_channels),
                 .flags = ADIS16400_HAS_PROD_ID |
-                                ADIS16400_HAS_SERIAL_NUMBER,
+                                ADIS16400_HAS_SERIAL_NUMBER |
+                                ADIS16400_BURST_DIAG_STAT,
                 .gyro_scale_micro = IIO_DEGREE_TO_RAD(10000), /* 0.01 deg/s */
                 .accel_scale_micro = IIO_G_TO_M_S_2(833), /* 1/1200 g */
                 .temp_scale_nano = 73860000, /* 0.07386 C */