iio: adc: at91-sama5d2: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

[ Upstream commit 8f884758966259fa8c50c137ac6d4ce9bb7859db ]

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: 5e1a1da0f8c9 ("iio: adc: at91-sama5d2_adc: add hw trigger and buffer support")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210613152301.571002-2-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index a7826f097b95cd71f4ff1498a87415b25e4f37cd..d356b515df090f6f85fa91b053dce6b4106ac4c4 100644 (file)
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -403,7 +403,8 @@ struct at91_adc_state {
        struct at91_adc_dma             dma_st;
        struct at91_adc_touch           touch_st;
        struct iio_dev                  *indio_dev;
-       u16                             buffer[AT91_BUFFER_MAX_HWORDS];
+       /* Ensure naturally aligned timestamp */
+       u16                             buffer[AT91_BUFFER_MAX_HWORDS] __aligned(8);
        /*
         * lock to prevent concurrent 'single conversion' requests through
         * sysfs.