iio: adc: Fix integration time/averaging for INA219/220
authorStefan Brüns <stefan.bruens@rwth-aachen.de>
Wed, 24 May 2017 00:09:06 +0000 (02:09 +0200)
committerJonathan Cameron <jic23@kernel.org>
Sat, 3 Jun 2017 09:01:57 +0000 (10:01 +0100)
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>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
drivers/iio/adc/ina2xx-adc.c

index bba10a1..232c0b8 100644 (file)
@@ -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
 #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);