iio: prox: srf08: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

To make code more readable, use a structure to express the channel
layout and ensure the timestamp is 8 byte aligned.

Found during an audit of all calls of uses of
iio_push_to_buffers_with_timestamp()

Fixes: 78f839029e1d ("iio: distance: srf08: add IIO driver for us ranger")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Andreas Klinger <ak@it-klinger.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-13-jic23@kernel.org

diff --git a/drivers/iio/proximity/srf08.c b/drivers/iio/proximity/srf08.c
index 70beac5c9c1dfc72ae8a3c9aacc044cb10f0b7eb..9b0886760f76de1480b3fbc5c5dc5a72401a107b 100644 (file)
--- a/drivers/iio/proximity/srf08.c
+++ b/drivers/iio/proximity/srf08.c
@@ -63,11 +63,11 @@ struct srf08_data {
        int                     range_mm;
        struct mutex            lock;
 
-       /*
-        * triggered buffer
-        * 1x16-bit channel + 3x16 padding + 4x16 timestamp
-        */
-       s16                     buffer[8];
+       /* Ensure timestamp is naturally aligned */
+       struct {
+               s16 chan;
+               s64 timestamp __aligned(8);
+       } scan;
 
        /* Sensor-Type */
        enum srf08_sensor_type  sensor_type;
@@ -190,9 +190,9 @@ static irqreturn_t srf08_trigger_handler(int irq, void *p)
 
        mutex_lock(&data->lock);
 
-       data->buffer[0] = sensor_data;
+       data->scan.chan = sensor_data;
        iio_push_to_buffers_with_timestamp(indio_dev,
-                                               data->buffer, pf->timestamp);
+                                          &data->scan, pf->timestamp);
 
        mutex_unlock(&data->lock);
 err: