iio: DAC: ad5624r_spi: fix bit shift of output data value

[ Upstream commit 09f4dcc9 ]

The value sent on the SPI bus is shifted by an erroneous number of bits.
The shift value was already computed in the iio_chan_spec structure and
hence subtracting this argument to 16 yields an erroneous data position
in the SPI stream.
Signed-off-by: JM Friedt <jmfriedt@femto-st.fr>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

drivers/iio/dac/ad5624r_spi.c

@@ -22,7 +22,7 @@
 #include "ad5624r.h"
 
 static int ad5624r_spi_write(struct spi_device *spi,
-			     u8 cmd, u8 addr, u16 val, u8 len)
+			     u8 cmd, u8 addr, u16 val, u8 shift)
 {
 	u32 data;
 	u8 msg[3];
@@ -35,7 +35,7 @@ static int ad5624r_spi_write(struct spi_device *spi,
 	 * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits,
 	 * for the AD5664R, AD5644R, and AD5624R, respectively.
 	 */
-	data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << (16 - len));
+	data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << shift);
 	msg[0] = data >> 16;
 	msg[1] = data >> 8;
 	msg[2] = data;