[PATCH 1/3] iio: adc: ina2xx: Mask flag bits in bus voltage register

From: Stefan BrÃns
Date: Sun Oct 01 2017 - 15:49:13 EST


Lower bits of the INA219/220 bus voltage register are conversion
status flags, properly mask the value.

Signed-off-by: Stefan BrÃns <stefan.bruens@xxxxxxxxxxxxxx>
---

drivers/iio/adc/ina2xx-adc.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c
index f387b972e4f4..361fb4e459d5 100644
--- a/drivers/iio/adc/ina2xx-adc.c
+++ b/drivers/iio/adc/ina2xx-adc.c
@@ -44,7 +44,6 @@

#define INA226_MASK_ENABLE 0x06
#define INA226_CVRF BIT(3)
-#define INA219_CNVR BIT(1)

#define INA2XX_MAX_REGISTERS 8

@@ -79,6 +78,11 @@
#define INA226_ITS_MASK GENMASK(5, 3)
#define INA226_SHIFT_ITS(val) ((val) << 3)

+/* INA219 Bus voltage register, low bits are flags */
+#define INA219_OVF BIT(0)
+#define INA219_CNVR BIT(1)
+#define INA219_BUS_VOLTAGE_MASK GENMASK(16, 3)
+
/* Cosmetic macro giving the sampling period for a full P=UxI cycle */
#define SAMPLING_PERIOD(c) ((c->int_time_vbus + c->int_time_vshunt) \
* c->avg)
@@ -170,6 +174,10 @@ static int ina2xx_read_raw(struct iio_dev *indio_dev,
else
*val = regval;

+ if ((chip->config->chip_id == ina219) &&
+ (chan->address == INA2XX_SHUNT_VOLTAGE))
+ *val &= INA219_BUS_VOLTAGE_MASK;
+
return IIO_VAL_INT;

case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
@@ -639,6 +647,10 @@ static int ina2xx_work_buffer(struct iio_dev *indio_dev)
if (ret < 0)
return ret;

+ if ((chip->config->chip_id == ina219) &&
+ (INA2XX_SHUNT_VOLTAGE + bit == INA2XX_BUS_VOLTAGE))
+ val &= INA219_BUS_VOLTAGE_MASK;
+
data[i++] = val;

if (INA2XX_SHUNT_VOLTAGE + bit == INA2XX_POWER)
--
2.14.1