[PATCH 01/10] iio: accel: sca3300: use struct with aligned_s64 timestamp

[David Lechner]

Use a struct with aligned_s64 timestamp instead of a padded array for
the buffer used for iio_push_to_buffers_with_ts(). This makes it easier
to see the correctness of the size and alignment of the buffer.

Changing the array part to s16 insted of u8 also lets us drop the cast
when it is used.

Signed-off-by: David Lechner <dlechner at baylibre.com>
---
 drivers/iio/accel/sca3300.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/iio/accel/sca3300.c b/drivers/iio/accel/sca3300.c
index 1132bbaba75bcca525fac2f3e19f63546380fd4f..f04ad523f48abd598b1b2df37c51da894c0ce796 100644
--- a/drivers/iio/accel/sca3300.c
+++ b/drivers/iio/accel/sca3300.c
@@ -58,15 +58,6 @@ enum sca3300_scan_indexes {
 	SCA3300_SCAN_MAX
 };
 
-/*
- * Buffer size max case:
- * Three accel channels, two bytes per channel.
- * Temperature channel, two bytes.
- * Three incli channels, two bytes per channel.
- * Timestamp channel, eight bytes.
- */
-#define SCA3300_MAX_BUFFER_SIZE (ALIGN(sizeof(s16) * SCA3300_SCAN_MAX, sizeof(s64)) + sizeof(s64))
-
 #define SCA3300_ACCEL_CHANNEL(index, reg, axis) {			\
 	.type = IIO_ACCEL,						\
 	.address = reg,							\
@@ -203,7 +194,10 @@ struct sca3300_data {
 	struct spi_device *spi;
 	struct mutex lock;
 	const struct sca3300_chip_info *chip;
-	u8 buffer[SCA3300_MAX_BUFFER_SIZE] __aligned(sizeof(s64));
+	struct {
+		s16 channels[SCA3300_SCAN_MAX];
+		aligned_s64 timestamp;
+	} buffer;
 	u8 txbuf[4] __aligned(IIO_DMA_MINALIGN);
 	u8 rxbuf[4];
 };
@@ -492,7 +486,7 @@ static irqreturn_t sca3300_trigger_handler(int irq, void *p)
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct sca3300_data *data = iio_priv(indio_dev);
 	int bit, ret, val, i = 0;
-	s16 *channels = (s16 *)data->buffer;
+	s16 *channels = data->buffer.channels;
 
 	iio_for_each_active_channel(indio_dev, bit) {
 		ret = sca3300_read_reg(data, indio_dev->channels[bit].address, &val);
@@ -505,7 +499,7 @@ static irqreturn_t sca3300_trigger_handler(int irq, void *p)
 		channels[i++] = val;
 	}
 
-	iio_push_to_buffers_with_ts(indio_dev, data->buffer,
+	iio_push_to_buffers_with_ts(indio_dev, &data->buffer,
 				    sizeof(data->buffer),
 				    iio_get_time_ns(indio_dev));
 out:

-- 
2.43.0