iio: adc: ti-ads1015: 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 this function.

Fixes: ecc24e72f437 ("iio: adc: Add TI ADS1015 ADC driver support")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Daniel Baluta <daniel.baluta@nxp.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-9-jic23@kernel.org

diff --git a/drivers/iio/adc/ti-ads1015.c b/drivers/iio/adc/ti-ads1015.c
index 9fef39b..5b82842 100644 (file)
--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -395,10 +395,14 @@ static irqreturn_t ads1015_trigger_handler(int irq, void *p)
        struct iio_poll_func *pf = p;
        struct iio_dev *indio_dev = pf->indio_dev;
        struct ads1015_data *data = iio_priv(indio_dev);
-       s16 buf[8]; /* 1x s16 ADC val + 3x s16 padding +  4x s16 timestamp */
+       /* Ensure natural alignment of timestamp */
+       struct {
+               s16 chan;
+               s64 timestamp __aligned(8);
+       } scan;
        int chan, ret, res;
 
-       memset(buf, 0, sizeof(buf));
+       memset(&scan, 0, sizeof(scan));
 
        mutex_lock(&data->lock);
        chan = find_first_bit(indio_dev->active_scan_mask,
@@ -409,10 +413,10 @@ static irqreturn_t ads1015_trigger_handler(int irq, void *p)
                goto err;
        }
 
-       buf[0] = res;
+       scan.chan = res;
        mutex_unlock(&data->lock);
 
-       iio_push_to_buffers_with_timestamp(indio_dev, buf,
+       iio_push_to_buffers_with_timestamp(indio_dev, &scan,
                                           iio_get_time_ns(indio_dev));
 
 err: