iio: proximity: isl29501: fix buffered read on big-endian systems

Fix passing a u32 value as a u16 buffer scan item. This works on little-
endian systems, but not on big-endian systems.

A new local variable is introduced for getting the register value and
the array is changed to a struct to make the data layout more explicit
rather than just changing the type and having to recalculate the proper
length needed for the timestamp.

Fixes: 1c28799 ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.")
Signed-off-by: David Lechner <[email protected]>
Link: https://patch.msgid.link/20250722-iio-use-more-iio_declare_buffer_with_ts-7-v2-1-d3ebeb001ed3@baylibre.com
Cc: <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

Author: dlech

drivers/iio/proximity/isl29501.c

@@ -938,12 +938,18 @@ static irqreturn_t isl29501_trigger_handler(int irq, void *p)
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct isl29501_private *isl29501 = iio_priv(indio_dev);
 	const unsigned long *active_mask = indio_dev->active_scan_mask;
-	u32 buffer[4] __aligned(8) = {}; /* 1x16-bit + naturally aligned ts */
-
-	if (test_bit(ISL29501_DISTANCE_SCAN_INDEX, active_mask))
-		isl29501_register_read(isl29501, REG_DISTANCE, buffer);
+	u32 value;
+	struct {
+		u16 data;
+		aligned_s64 ts;
+	} scan = { };
+
+	if (test_bit(ISL29501_DISTANCE_SCAN_INDEX, active_mask)) {
+		isl29501_register_read(isl29501, REG_DISTANCE, &value);
+		scan.data = value;
+	}
 
-	iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp);
+	iio_push_to_buffers_with_timestamp(indio_dev, &scan, pf->timestamp);
 	iio_trigger_notify_done(indio_dev->trig);
 
 	return IRQ_HANDLED;