iio: adc: Fix integration time/averaging for INA219/220

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

@@ -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 (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 = ina226_set_int_time_vshunt(chip, val2, &tmp);
+				ret = ina219_set_int_time_vshunt(chip, val2,
+								 &tmp);
 			else
-			ret = ina226_set_int_time_vbus(chip, val2, &tmp);
+				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);