iio: adc: ti-ads8344: properly byte swap value

The first received byte is the MSB, followed by the LSB so the value needs
to be byte swapped.

Also, the ADC actually has a delay of one clock on the SPI bus. Read three
bytes to get the last bit.

Fixes: 8dd2d7c0fe ("iio: adc: Add driver for the TI ADS8344 A/DC chips")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Alexandre Belloni 2020-04-16 22:54:27 +02:00 committed by Jonathan Cameron
parent 0a2bf9200a
commit dd7de4c002

View File

@ -29,7 +29,7 @@ struct ads8344 {
struct mutex lock;
u8 tx_buf ____cacheline_aligned;
u16 rx_buf;
u8 rx_buf[3];
};
#define ADS8344_VOLTAGE_CHANNEL(chan, si) \
@ -89,11 +89,11 @@ static int ads8344_adc_conversion(struct ads8344 *adc, int channel,
udelay(9);
ret = spi_read(spi, &adc->rx_buf, 2);
ret = spi_read(spi, adc->rx_buf, sizeof(adc->rx_buf));
if (ret)
return ret;
return adc->rx_buf;
return adc->rx_buf[0] << 9 | adc->rx_buf[1] << 1 | adc->rx_buf[2] >> 7;
}
static int ads8344_read_raw(struct iio_dev *iio,