[PATCH v2 2/3] iio: adc: Fix integration time/averaging for INA219/220

Stefan Brüns
2017-05-24T00:09:22Z

INA226/230/231 has integration times per voltage channel and common
averaging setting for both channels, while the INA219/220 only has a
combined integration time/averaging setting per channel.
Only expose the averaging attribute for the INA226, and expose the correct
integration times for the INA219.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
---
drivers/iio/adc/ina2xx-adc.c | 204 ++++++++++++++++++++++++++++++++++++++-----
1 file changed, 182 insertions(+), 22 deletions(-)

diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c
index bba10a1b2fcb..232c0b80d658 100644
--- a/drivers/iio/adc/ina2xx-adc.c
+++ b/drivers/iio/adc/ina2xx-adc.c
@@ -49,6 +49,7 @@

/* settings - depend on use case */
#define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
+#define INA219_DEFAULT_IT 532
#define INA226_CONFIG_DEFAULT 0x4327
#define INA226_DEFAULT_AVG 4
#define INA226_DEFAULT_IT 1110
@@ -56,19 +57,24 @@
#define INA2XX_RSHUNT_DEFAULT 10000

/*
- * bit mask for reading the averaging setting in the configuration register
+ * bit masks for reading the settings in the configuration register
* FIXME: use regmap_fields.
*/
#define INA2XX_MODE_MASK GENMASK(3, 0)

+/* Averaging for VBus/VShunt/Power */
#define INA226_AVG_MASK GENMASK(11, 9)
#define INA226_SHIFT_AVG(val) ((val) << 9)

/* Integration time for VBus */
+#define INA219_ITB_MASK GENMASK(10, 7)
+#define INA219_SHIFT_ITB(val) ((val) << 7)
#define INA226_ITB_MASK GENMASK(8, 6)
#define INA226_SHIFT_ITB(val) ((val) << 6)

/* Integration time for VShunt */
+#define INA219_ITS_MASK GENMASK(6, 3)
+#define INA219_SHIFT_ITS(val) ((val) << 3)
#define INA226_ITS_MASK GENMASK(5, 3)
#define INA226_SHIFT_ITS(val) ((val) << 3)

@@ -108,6 +114,7 @@ struct ina2xx_config {
int bus_voltage_shift;
int bus_voltage_lsb; /* uV */
int power_lsb; /* uW */
+ enum ina2xx_ids chip_id;
};

struct ina2xx_chip_info {
@@ -130,6 +137,7 @@ static const struct ina2xx_config ina2xx_config[] = {
.bus_voltage_shift = 3,
.bus_voltage_lsb = 4000,
.power_lsb = 20000,
+ .chip_id = ina219,
},
[ina226] = {
.config_default = INA226_CONFIG_DEFAULT,
@@ -138,6 +146,7 @@ static const struct ina2xx_config ina2xx_config[] = {
.bus_voltage_shift = 0,
.bus_voltage_lsb = 1250,
.power_lsb = 25000,
+ .chip_id = ina226,
},
};

@@ -283,6 +292,66 @@ static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip,
return 0;
}

+/* Conversion times in uS. */
+static const int ina219_conv_time_tab_subsample[] = { 84, 148, 276, 532 };
+static const int ina219_conv_time_tab_average[] = { 532, 1060, 2130, 4260,
+ 8510, 17020, 34050, 68100};
+
+static int ina219_lookup_int_time(unsigned int *val_us, int *bits)
+{
+ if (*val_us > 68100 || *val_us < 84)
+ return -EINVAL;
+
+ if (*val_us <= 532) {
+ *bits = find_closest(*val_us, ina219_conv_time_tab_subsample,
+ ARRAY_SIZE(ina219_conv_time_tab_subsample));
+ *val_us = ina219_conv_time_tab_subsample[*bits];
+ } else {
+ *bits = find_closest(*val_us, ina219_conv_time_tab_average,
+ ARRAY_SIZE(ina219_conv_time_tab_average));
+ *val_us = ina219_conv_time_tab_average[*bits];
+ *bits |= 0x8;
+ }
+
+ return 0;
+}
+
+static int ina219_set_int_time_vbus(struct ina2xx_chip_info *chip,
+ unsigned int val_us, unsigned int *config)
+{
+ int bits, ret;
+ unsigned int val_us_best = val_us;
+
+ ret = ina219_lookup_int_time(&val_us_best, &bits);
+ if (ret)
+ return ret;
+
+ chip->int_time_vbus = val_us_best;
+
+ *config &= ~INA219_ITB_MASK;
+ *config |= INA219_SHIFT_ITB(bits) & INA219_ITB_MASK;
+
+ return 0;
+}
+
+static int ina219_set_int_time_vshunt(struct ina2xx_chip_info *chip,
+ unsigned int val_us, unsigned int *config)
+{
+ int bits, ret;
+ unsigned int val_us_best = val_us;
+
+ ret = ina219_lookup_int_time(&val_us_best, &bits);
+ if (ret)
+ return ret;
+
+ chip->int_time_vshunt = val_us_best;
+
+ *config &= ~INA219_ITS_MASK;
+ *config |= INA219_SHIFT_ITS(bits) & INA219_ITS_MASK;
+
+ return 0;
+}
+
static int ina2xx_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
@@ -308,10 +377,21 @@ static int ina2xx_write_raw(struct iio_dev *indio_dev,
break;

case IIO_CHAN_INFO_INT_TIME:
- if (chan->address == INA2XX_SHUNT_VOLTAGE)
- ret = ina226_set_int_time_vshunt(chip, val2, &tmp);
- else
- ret = ina226_set_int_time_vbus(chip, val2, &tmp);
+ if (chip->config->chip_id == ina226) {
+ if (chan->address == INA2XX_SHUNT_VOLTAGE)
+ ret = ina226_set_int_time_vshunt(chip, val2,
+ &tmp);
+ else
+ ret = ina226_set_int_time_vbus(chip, val2,
+ &tmp);
+ } else {
+ if (chan->address == INA2XX_SHUNT_VOLTAGE)
+ ret = ina219_set_int_time_vshunt(chip, val2,
+ &tmp);
+ else
+ ret = ina219_set_int_time_vbus(chip, val2,
+ &tmp);
+ }
break;

default:
@@ -412,7 +492,24 @@ static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
return len;
}

-#define INA2XX_CHAN(_type, _index, _address) { \
+#define INA219_CHAN(_type, _index, _address) { \
+ .type = (_type), \
+ .address = (_address), \
+ .indexed = 1, \
+ .channel = (_index), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .scan_index = (_index), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 16, \
+ .storagebits = 16, \
+ .endianness = IIO_CPU, \
+ } \
+}
+
+#define INA226_CHAN(_type, _index, _address) { \
.type = (_type), \
.address = (_address), \
.indexed = 1, \
@@ -434,7 +531,25 @@ static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
* Sampling Freq is a consequence of the integration times of
* the Voltage channels.
*/
-#define INA2XX_CHAN_VOLTAGE(_index, _address) { \
+#define INA219_CHAN_VOLTAGE(_index, _address) { \
+ .type = IIO_VOLTAGE, \
+ .address = (_address), \
+ .indexed = 1, \
+ .channel = (_index), \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_INT_TIME), \
+ .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .scan_index = (_index), \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 16, \
+ .storagebits = 16, \
+ .endianness = IIO_LE, \
+ } \
+}
+
+#define INA226_CHAN_VOLTAGE(_index, _address) { \
.type = IIO_VOLTAGE, \
.address = (_address), \
.indexed = 1, \
@@ -453,11 +568,20 @@ static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
} \
}

-static const struct iio_chan_spec ina2xx_channels[] = {
- INA2XX_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
- INA2XX_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
- INA2XX_CHAN(IIO_POWER, 2, INA2XX_POWER),
- INA2XX_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
+
+static const struct iio_chan_spec ina226_channels[] = {
+ INA226_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
+ INA226_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
+ INA226_CHAN(IIO_POWER, 2, INA2XX_POWER),
+ INA226_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
+ IIO_CHAN_SOFT_TIMESTAMP(4),
+};
+
+static const struct iio_chan_spec ina219_channels[] = {
+ INA219_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
+ INA219_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
+ INA219_CHAN(IIO_POWER, 2, INA2XX_POWER),
+ INA219_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
IIO_CHAN_SOFT_TIMESTAMP(4),
};

@@ -592,7 +716,14 @@ static int ina2xx_debug_reg(struct iio_dev *indio_dev,
}

/* Possible integration times for vshunt and vbus */
-static IIO_CONST_ATTR_INT_TIME_AVAIL("0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");
+static IIO_CONST_ATTR_NAMED(ina219_integration_time_available,
+ integration_time_available,
+ "0.000084 0.000148 0.000276 0.000532 0.001060 0.002130 0.004260 0.008510 0.017020 0.034050 0.068100");
+
+static IIO_CONST_ATTR_NAMED(ina226_integration_time_available,
+ integration_time_available,
+ "0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");
+

static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR,
ina2xx_allow_async_readout_show,
@@ -602,20 +733,39 @@ static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR,
ina2xx_shunt_resistor_show,
ina2xx_shunt_resistor_store, 0);

-static struct attribute *ina2xx_attributes[] = {
+static struct attribute *ina219_attributes[] = {
+ &iio_dev_attr_in_allow_async_readout.dev_attr.attr,
+ &iio_const_attr_ina219_integration_time_available.dev_attr.attr,
+ &iio_dev_attr_in_shunt_resistor.dev_attr.attr,
+ NULL,
+};
+
+static struct attribute *ina226_attributes[] = {
&iio_dev_attr_in_allow_async_readout.dev_attr.attr,
- &iio_const_attr_integration_time_available.dev_attr.attr,
+ &iio_const_attr_ina226_integration_time_available.dev_attr.attr,
&iio_dev_attr_in_shunt_resistor.dev_attr.attr,
NULL,
};

-static const struct attribute_group ina2xx_attribute_group = {
- .attrs = ina2xx_attributes,
+static const struct attribute_group ina219_attribute_group = {
+ .attrs = ina219_attributes,
};

-static const struct iio_info ina2xx_info = {
+static const struct attribute_group ina226_attribute_group = {
+ .attrs = ina226_attributes,
+};
+
+static const struct iio_info ina219_info = {
+ .driver_module = THIS_MODULE,
+ .attrs = &ina219_attribute_group,
+ .read_raw = ina2xx_read_raw,
+ .write_raw = ina2xx_write_raw,
+ .debugfs_reg_access = ina2xx_debug_reg,
+};
+
+static const struct iio_info ina226_info = {
.driver_module = THIS_MODULE,
- .attrs = &ina2xx_attribute_group,
+ .attrs = &ina226_attribute_group,
.read_raw = ina2xx_read_raw,
.write_raw = ina2xx_write_raw,
.debugfs_reg_access = ina2xx_debug_reg,
@@ -686,6 +836,10 @@ static int ina2xx_probe(struct i2c_client *client,
ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
+ } else {
+ chip->avg = 1;
+ ina219_set_int_time_vbus(chip, INA219_DEFAULT_IT, &val);
+ ina219_set_int_time_vshunt(chip, INA219_DEFAULT_IT, &val);
}

ret = ina2xx_init(chip, val);
@@ -697,10 +851,16 @@ static int ina2xx_probe(struct i2c_client *client,
indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
indio_dev->dev.parent = &client->dev;
indio_dev->dev.of_node = client->dev.of_node;
- indio_dev->channels = ina2xx_channels;
- indio_dev->num_channels = ARRAY_SIZE(ina2xx_channels);
+ if (id->driver_data == ina226) {
+ indio_dev->channels = ina226_channels;
+ indio_dev->num_channels = ARRAY_SIZE(ina226_channels);
+ indio_dev->info = &ina226_info;
+ } else {
+ indio_dev->channels = ina219_channels;
+ indio_dev->num_channels = ARRAY_SIZE(ina219_channels);
+ indio_dev->info = &ina219_info;
+ }
indio_dev->name = id->name;
- indio_dev->info = &ina2xx_info;
indio_dev->setup_ops = &ina2xx_setup_ops;

buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
--
2.12.2