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Message-Id: <20200416205428.437503-2-alexandre.belloni@bootlin.com>
Date: Thu, 16 Apr 2020 22:54:27 +0200
From: Alexandre Belloni <alexandre.belloni@...tlin.com>
To: Jonathan Cameron <jic23@...nel.org>
Cc: Hartmut Knaack <knaack.h@....de>,
Lars-Peter Clausen <lars@...afoo.de>,
Peter Meerwald-Stadler <pmeerw@...erw.net>,
Gregory CLEMENT <gregory.clement@...tlin.com>,
linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org,
Alexandre Belloni <alexandre.belloni@...tlin.com>
Subject: [PATCH v2 1/2] 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: 8dd2d7c0fed7 ("iio: adc: Add driver for the TI ADS8344 A/DC chips")
Signed-off-by: Alexandre Belloni <alexandre.belloni@...tlin.com>
---
drivers/iio/adc/ti-ads8344.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/iio/adc/ti-ads8344.c b/drivers/iio/adc/ti-ads8344.c
index 9a460807d46d..abe4b56c847c 100644
--- a/drivers/iio/adc/ti-ads8344.c
+++ b/drivers/iio/adc/ti-ads8344.c
@@ -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,
--
2.25.2
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