[PATCH 6/6] iio: adc: ad7173: Add support for AD411x devices

From: Dumitru Ceclan via B4 Relay
Date: Mon Apr 01 2024 - 11:11:52 EST

From: Dumitru Ceclan <dumitru.ceclan@xxxxxxxxxx>

Add support for AD4111/AD4112/AD4114/AD4115/AD4116.

The AD411X family encompasses a series of low power, low noise, 24-bit,
sigma-delta analog-to-digital converters that offer a versatile range of
specifications.

This family of ADCs integrates an analog front end suitable for processing
both fully differential and single-ended, bipolar voltage inputs
addressing a wide array of industrial and instrumentation requirements.

- All ADCs have inputs with a precision voltage divider with a division
ratio of 10.
- AD4116 has 5 low level inputs without a voltage divider.
- AD4111 and AD4112 support current inputs (0 mA to 20 mA) using a 50ohm
shunt resistor.

Signed-off-by: Dumitru Ceclan <dumitru.ceclan@xxxxxxxxxx>
---
drivers/iio/adc/ad7173.c | 224 ++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 210 insertions(+), 14 deletions(-)

diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
index 9526585e6929..ac32bd7dbd1e 100644
--- a/drivers/iio/adc/ad7173.c
+++ b/drivers/iio/adc/ad7173.c
@@ -1,8 +1,9 @@
// SPDX-License-Identifier: GPL-2.0+
/*
- * AD717x family SPI ADC driver
+ * AD717x and AD411x family SPI ADC driver
*
* Supported devices:
+ * AD4111/AD4112/AD4114/AD4115/AD4116
* AD7172-2/AD7172-4/AD7173-8/AD7175-2
* AD7175-8/AD7176-2/AD7177-2
*
@@ -72,6 +73,11 @@
#define AD7175_2_ID 0x0cd0
#define AD7172_4_ID 0x2050
#define AD7173_ID 0x30d0
+#define AD4111_ID 0x30d0
+#define AD4112_ID 0x30d0
+#define AD4114_ID 0x30d0
+#define AD4116_ID 0x34d0
+#define AD4115_ID 0x38d0
#define AD7175_8_ID 0x3cd0
#define AD7177_ID 0x4fd0
#define AD7173_ID_MASK GENMASK(15, 4)
@@ -120,11 +126,20 @@
#define AD7173_VOLTAGE_INT_REF_uV 2500000
#define AD7173_TEMP_SENSIIVITY_uV_per_C 477
#define AD7177_ODR_START_VALUE 0x07
+#define AD4111_SHUNT_RESISTOR_OHM 50
+#define AD4111_DIVIDER_RATIO 10
+#define AD411X_VCOM_INPUT 0X10
+#define AD4111_CURRENT_CHAN_CUTOFF 16

#define AD7173_FILTER_ODR0_MASK GENMASK(5, 0)
#define AD7173_MAX_CONFIGS 8

enum ad7173_ids {
+ ID_AD4111,
+ ID_AD4112,
+ ID_AD4114,
+ ID_AD4115,
+ ID_AD4116,
ID_AD7172_2,
ID_AD7172_4,
ID_AD7173_8,
@@ -134,16 +149,26 @@ enum ad7173_ids {
ID_AD7177_2,
};

+enum ad4111_current_channels {
+ AD4111_CURRENT_IN0P_IN0N,
+ AD4111_CURRENT_IN1P_IN1N,
+ AD4111_CURRENT_IN2P_IN2N,
+ AD4111_CURRENT_IN3P_IN3N,
+};
+
struct ad7173_device_info {
const unsigned int *sinc5_data_rates;
unsigned int num_sinc5_data_rates;
unsigned int odr_start_value;
+ unsigned int num_inputs_with_divider;
unsigned int num_channels;
unsigned int num_configs;
unsigned int num_inputs;
unsigned int clock;
unsigned int id;
char *name;
+ bool has_current_inputs;
+ bool has_vcom;
bool has_temp;
bool has_input_buf;
bool has_int_ref;
@@ -189,6 +214,24 @@ struct ad7173_state {
#endif
};

+static unsigned int ad4115_sinc5_data_rates[] = {
+ 24845000, 24845000, 20725000, 20725000, /* 0-3 */
+ 15564000, 13841000, 10390000, 10390000, /* 4-7 */
+ 4994000, 2499000, 1000000, 500000, /* 8-11 */
+ 395500, 200000, 100000, 59890, /* 12-15 */
+ 49920, 20000, 16660, 10000, /* 16-19 */
+ 5000, 2500, 2500, /* 20-22 */
+};
+
+static unsigned int ad4116_sinc5_data_rates[] = {
+ 12422360, 12422360, 12422360, 12422360, /* 0-3 */
+ 10362690, 10362690, 7782100, 6290530, /* 4-7 */
+ 5194800, 2496900, 1007600, 499900, /* 8-11 */
+ 390600, 200300, 100000, 59750, /* 12-15 */
+ 49840, 20000, 16650, 10000, /* 16-19 */
+ 5000, 2500, 1250, /* 20-22 */
+};
+
static const unsigned int ad7173_sinc5_data_rates[] = {
6211000, 6211000, 6211000, 6211000, 6211000, 6211000, 5181000, 4444000, /* 0-7 */
3115000, 2597000, 1007000, 503800, 381000, 200300, 100500, 59520, /* 8-15 */
@@ -204,7 +247,91 @@ static const unsigned int ad7175_sinc5_data_rates[] = {
5000, /* 20 */
};

+static unsigned int ad4111_current_channel_config[] = {
+ [AD4111_CURRENT_IN0P_IN0N] = 0x1E8,
+ [AD4111_CURRENT_IN1P_IN1N] = 0x1C9,
+ [AD4111_CURRENT_IN2P_IN2N] = 0x1AA,
+ [AD4111_CURRENT_IN3P_IN3N] = 0x18B,
+};
+
static const struct ad7173_device_info ad7173_device_info[] = {
+ [ID_AD4111] = {
+ .id = AD4111_ID,
+ .num_inputs_with_divider = 8,
+ .num_channels = 16,
+ .num_configs = 8,
+ .num_inputs = 8,
+ .num_gpios = 2,
+ .has_temp = true,
+ .has_vcom = true,
+ .has_input_buf = true,
+ .has_current_inputs = true,
+ .has_int_ref = true,
+ .clock = 2 * HZ_PER_MHZ,
+ .sinc5_data_rates = ad7173_sinc5_data_rates,
+ .num_sinc5_data_rates = ARRAY_SIZE(ad7173_sinc5_data_rates),
+ },
+ [ID_AD4112] = {
+ .id = AD4112_ID,
+ .num_inputs_with_divider = 8,
+ .num_channels = 16,
+ .num_configs = 8,
+ .num_inputs = 8,
+ .num_gpios = 2,
+ .has_vcom = true,
+ .has_temp = true,
+ .has_input_buf = true,
+ .has_current_inputs = true,
+ .has_int_ref = true,
+ .clock = 2 * HZ_PER_MHZ,
+ .sinc5_data_rates = ad7173_sinc5_data_rates,
+ .num_sinc5_data_rates = ARRAY_SIZE(ad7173_sinc5_data_rates),
+ },
+ [ID_AD4114] = {
+ .id = AD4114_ID,
+ .num_inputs_with_divider = 16,
+ .num_channels = 16,
+ .num_configs = 8,
+ .num_inputs = 16,
+ .num_gpios = 4,
+ .has_vcom = true,
+ .has_temp = true,
+ .has_input_buf = true,
+ .has_int_ref = true,
+ .clock = 2 * HZ_PER_MHZ,
+ .sinc5_data_rates = ad7173_sinc5_data_rates,
+ .num_sinc5_data_rates = ARRAY_SIZE(ad7173_sinc5_data_rates),
+ },
+ [ID_AD4115] = {
+ .id = AD4115_ID,
+ .num_inputs_with_divider = 16,
+ .num_channels = 16,
+ .num_configs = 8,
+ .num_inputs = 16,
+ .num_gpios = 4,
+ .has_vcom = true,
+ .has_temp = true,
+ .has_input_buf = true,
+ .has_int_ref = true,
+ .clock = 8 * HZ_PER_MHZ,
+ .sinc5_data_rates = ad4115_sinc5_data_rates,
+ .num_sinc5_data_rates = ARRAY_SIZE(ad4115_sinc5_data_rates),
+ },
+ [ID_AD4116] = {
+ .id = AD4116_ID,
+ .num_inputs_with_divider = 11,
+ .num_channels = 16,
+ .num_configs = 8,
+ .num_inputs = 16,
+ .num_gpios = 4,
+ .has_vcom = true,
+ .has_temp = true,
+ .has_input_buf = true,
+ .has_int_ref = true,
+ .clock = 4 * HZ_PER_MHZ,
+ .sinc5_data_rates = ad4116_sinc5_data_rates,
+ .num_sinc5_data_rates = ARRAY_SIZE(ad4116_sinc5_data_rates),
+ },
[ID_AD7172_2] = {
.name = "ad7172-2",
.id = AD7172_2_ID,
@@ -670,18 +797,34 @@ static int ad7173_read_raw(struct iio_dev *indio_dev,

return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
- if (chan->type == IIO_TEMP) {
+
+ switch (chan->type) {
+ case IIO_TEMP:
temp = AD7173_VOLTAGE_INT_REF_uV * MILLI;
temp /= AD7173_TEMP_SENSIIVITY_uV_per_C;
*val = temp;
*val2 = chan->scan_type.realbits;
- } else {
+ break;
+ case IIO_VOLTAGE:
*val = ad7173_get_ref_voltage_milli(st, ch->cfg.ref_sel);
*val2 = chan->scan_type.realbits - !!(ch->cfg.bipolar);
+
+ if (chan->channel < st->info->num_inputs_with_divider)
+ *val *= AD4111_DIVIDER_RATIO;
+ break;
+ case IIO_CURRENT:
+ *val = ad7173_get_ref_voltage_milli(st, ch->cfg.ref_sel);
+ *val /= AD4111_SHUNT_RESISTOR_OHM;
+ *val2 = chan->scan_type.realbits - !!(ch->cfg.bipolar);
+ break;
+ default:
+ return -EINVAL;
}
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
- if (chan->type == IIO_TEMP) {
+
+ switch (chan->type) {
+ case IIO_TEMP:
/* 0 Kelvin -> raw sample */
temp = -ABSOLUTE_ZERO_MILLICELSIUS;
temp *= AD7173_TEMP_SENSIIVITY_uV_per_C;
@@ -690,8 +833,13 @@ static int ad7173_read_raw(struct iio_dev *indio_dev,
AD7173_VOLTAGE_INT_REF_uV *
MILLI);
*val = -temp;
- } else {
+ break;
+ case IIO_VOLTAGE:
+ case IIO_CURRENT:
*val = -BIT(chan->scan_type.realbits - 1);
+ break;
+ default:
+ return -EINVAL;
}
return IIO_VAL_INT;
case IIO_CHAN_INFO_SAMP_FREQ:
@@ -909,6 +1057,24 @@ static int ad7173_register_clk_provider(struct iio_dev *indio_dev)
&st->int_clk_hw);
}

+static int ad4111_validate_current_ain(struct ad7173_state *st,
+ unsigned int ain[2])
+{
+ struct device *dev = &st->sd.spi->dev;
+
+ if (!st->info->has_current_inputs)
+ return dev_err_probe(dev, -EINVAL,
+ "Reg values equal to or higher than %d are restricted to models with current channels.\n",
+ AD4111_CURRENT_CHAN_CUTOFF);
+
+ if (ain[1] != 0 && ain[0] >= ARRAY_SIZE(ad4111_current_channel_config))
+ return dev_err_probe(dev, -EINVAL,
+ "For current channel diff-channels must be <[0-%d],0>\n",
+ ARRAY_SIZE(ad4111_current_channel_config) - 1);
+
+ return 0;
+}
+
static int ad7173_validate_voltage_ain_inputs(struct ad7173_state *st,
unsigned int ain[2])
{
@@ -951,7 +1117,7 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
struct device *dev = indio_dev->dev.parent;
struct iio_chan_spec *chan_arr, *chan;
unsigned int ain[2], chan_index = 0;
- int ref_sel, ret, num_channels;
+ int ref_sel, ret, reg, num_channels;

num_channels = device_get_child_node_count(dev);

@@ -1004,10 +1170,20 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
if (ret)
return ret;

- ret = ad7173_validate_voltage_ain_inputs(st, ain);
+ ret = fwnode_property_read_u32(child, "reg", &reg);
if (ret)
return ret;

+ if (reg >= AD4111_CURRENT_CHAN_CUTOFF) {
+ ret = ad4111_validate_current_ain(st, ain);
+ if (ret)
+ return ret;
+ } else {
+ ret = ad7173_validate_voltage_ain_inputs(st, ain);
+ if (ret)
+ return ret;
+ }
+
ret = fwnode_property_match_property_string(child,
"adi,reference-select",
ad7173_ref_sel_str,
@@ -1028,15 +1204,22 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
*chan = ad7173_channel_template;
chan->address = chan_index;
chan->scan_index = chan_index;
- chan->channel = ain[0];
- chan->channel2 = ain[1];
- chan->differential = true;

- chan_st_priv->ain = AD7173_CH_ADDRESS(ain[0], ain[1]);
+ if (reg >= AD4111_CURRENT_CHAN_CUTOFF) {
+ chan->type = IIO_CURRENT;
+ chan->channel = ain[0];
+ chan_st_priv->ain = ad4111_current_channel_config[ain[0]];
+ } else {
+ chan->channel = ain[0];
+ chan->channel2 = ain[1];
+ chan->differential = true;
+
+ chan_st_priv->ain = AD7173_CH_ADDRESS(ain[0], ain[1]);
+ chan_st_priv->cfg.input_buf = st->info->has_input_buf;
+ }
+
chan_st_priv->chan_reg = chan_index;
- chan_st_priv->cfg.input_buf = st->info->has_input_buf;
chan_st_priv->cfg.odr = 0;
-
chan_st_priv->cfg.bipolar = fwnode_property_read_bool(child, "bipolar");
if (chan_st_priv->cfg.bipolar)
chan->info_mask_separate |= BIT(IIO_CHAN_INFO_OFFSET);
@@ -1167,6 +1350,14 @@ static int ad7173_probe(struct spi_device *spi)
}

static const struct of_device_id ad7173_of_match[] = {
+ { .compatible = "ad4111",
+ .data = &ad7173_device_info[ID_AD4111]},
+ { .compatible = "ad4112",
+ .data = &ad7173_device_info[ID_AD4112]},
+ { .compatible = "ad4114",
+ .data = &ad7173_device_info[ID_AD4114]},
+ { .compatible = "ad4115",
+ .data = &ad7173_device_info[ID_AD4115]},
{ .compatible = "adi,ad7172-2",
.data = &ad7173_device_info[ID_AD7172_2]},
{ .compatible = "adi,ad7172-4",
@@ -1186,6 +1377,11 @@ static const struct of_device_id ad7173_of_match[] = {
MODULE_DEVICE_TABLE(of, ad7173_of_match);

static const struct spi_device_id ad7173_id_table[] = {
+ { "ad4111", (kernel_ulong_t)&ad7173_device_info[ID_AD4111]},
+ { "ad4112", (kernel_ulong_t)&ad7173_device_info[ID_AD4112]},
+ { "ad4114", (kernel_ulong_t)&ad7173_device_info[ID_AD4114]},
+ { "ad4115", (kernel_ulong_t)&ad7173_device_info[ID_AD4115]},
+ { "ad4116", (kernel_ulong_t)&ad7173_device_info[ID_AD4116]},
{ "ad7172-2", (kernel_ulong_t)&ad7173_device_info[ID_AD7172_2]},
{ "ad7172-4", (kernel_ulong_t)&ad7173_device_info[ID_AD7172_4]},
{ "ad7173-8", (kernel_ulong_t)&ad7173_device_info[ID_AD7173_8]},
@@ -1210,5 +1406,5 @@ module_spi_driver(ad7173_driver);
MODULE_IMPORT_NS(IIO_AD_SIGMA_DELTA);
MODULE_AUTHOR("Lars-Peter Clausen <lars@xxxxxxxxx>");
MODULE_AUTHOR("Dumitru Ceclan <dumitru.ceclan@xxxxxxxxxx>");
-MODULE_DESCRIPTION("Analog Devices AD7172/AD7173/AD7175/AD7176 ADC driver");
+MODULE_DESCRIPTION("Analog Devices AD717x and AD411x ADC driver");
MODULE_LICENSE("GPL");

--
2.43.0