[PATCH v2 2/6] iio: adc: ad4695: use u16 for buffer elements

[David Lechner]

Change the type of the buffer elements to u16 since we currently only
support 16-bit word size. The code was originally written to also allow
for 32-bit word size when oversampling is enabled, but so far,
oversampling is only implemented when using SPI offload and therefore
doesn't use this buffer.

AD4695_MAX_CHANNEL_SIZE macro is dropped since it no longer adds any
value.

AD4695_MAX_CHANNELS + 2 is changed to AD4695_MAX_CHANNELS + 1 because
previously we were overallocating. AD4695_MAX_CHANNELS is the number of
of voltage channels and + 1 is for the temperature channel.

Signed-off-by: David Lechner <dlechner at baylibre.com>
---
 drivers/iio/adc/ad4695.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/iio/adc/ad4695.c b/drivers/iio/adc/ad4695.c
index 68c6625db0d75f4cade7cb029e94191118dbcaa0..0c633d43e480d5404074e9fa35f1d330b448f0a2 100644
--- a/drivers/iio/adc/ad4695.c
+++ b/drivers/iio/adc/ad4695.c
@@ -106,8 +106,6 @@
 
 /* Max number of voltage input channels. */
 #define AD4695_MAX_CHANNELS		16
-/* Max size of 1 raw sample in bytes. */
-#define AD4695_MAX_CHANNEL_SIZE		2
 
 enum ad4695_in_pair {
 	AD4695_IN_PAIR_REFGND,
@@ -162,8 +160,8 @@ struct ad4695_state {
 	struct spi_transfer buf_read_xfer[AD4695_MAX_CHANNELS * 2 + 3];
 	struct spi_message buf_read_msg;
 	/* Raw conversion data received. */
-	u8 buf[ALIGN((AD4695_MAX_CHANNELS + 2) * AD4695_MAX_CHANNEL_SIZE,
-		     sizeof(s64)) + sizeof(s64)] __aligned(IIO_DMA_MINALIGN);
+	u16 buf[ALIGN((AD4695_MAX_CHANNELS + 1) * sizeof(u16),
+		      sizeof(s64)) + sizeof(s64)] __aligned(IIO_DMA_MINALIGN);
 	u16 raw_data;
 	/* Commands to send for single conversion. */
 	u16 cnv_cmd;
@@ -660,9 +658,8 @@ static int ad4695_buffer_preenable(struct iio_dev *indio_dev)
 	iio_for_each_active_channel(indio_dev, bit) {
 		xfer = &st->buf_read_xfer[num_xfer];
 		xfer->bits_per_word = 16;
-		xfer->rx_buf = &st->buf[rx_buf_offset];
+		xfer->rx_buf = &st->buf[rx_buf_offset++];
 		xfer->len = 2;
-		rx_buf_offset += xfer->len;
 
 		if (bit == temp_chan_bit) {
 			temp_en = 1;

-- 
2.43.0