[PATCH v7 9/9] iio: adc: ad7173: Add support for AD411x devices

From: Dumitru Ceclan via B4 Relay
Date: Fri Jun 07 2024 - 10:59:43 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 | 314 ++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 282 insertions(+), 32 deletions(-)

diff --git a/drivers/iio/adc/ad7173.c b/drivers/iio/adc/ad7173.c
index 22dcf89ef3ef..6fbbdccff20b 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
*
@@ -80,6 +81,11 @@
#define AD7175_2_ID 0x0cd0
#define AD7172_4_ID 0x2050
#define AD7173_ID 0x30d0
+#define AD4111_ID AD7173_ID
+#define AD4112_ID AD7173_ID
+#define AD4114_ID AD7173_ID
+#define AD4116_ID 0x34d0
+#define AD4115_ID 0x38d0
#define AD7175_8_ID 0x3cd0
#define AD7177_ID 0x4fd0
#define AD7173_ID_MASK GENMASK(15, 4)
@@ -110,6 +116,7 @@

#define AD7173_GPO12_DATA(x) BIT((x) + 0)
#define AD7173_GPO23_DATA(x) BIT((x) + 4)
+#define AD4111_GPO01_DATA(x) BIT((x) + 6)
#define AD7173_GPO_DATA(x) ((x) < 2 ? AD7173_GPO12_DATA(x) : AD7173_GPO23_DATA(x))

#define AD7173_INTERFACE_DATA_STAT BIT(6)
@@ -128,6 +135,16 @@
#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 AD4111_CURRENT_CHAN_CUTOFF 16
+#define AD4111_VINCOM_INPUT 0x10
+
+/* pin < num_voltage_in is a normal voltage input */
+/* pin >= num_voltage_in_div is a voltage input without a divider */
+#define AD4111_IS_VINCOM_MISMATCH(pin1, pin2) ((pin1) == AD4111_VINCOM_INPUT && \
+ (pin2) < st->info->num_voltage_in && \
+ (pin2) >= st->info->num_voltage_in_div)

#define AD7173_FILTER_ODR0_MASK GENMASK(5, 0)
#define AD7173_MAX_CONFIGS 8
@@ -136,18 +153,27 @@ struct ad7173_device_info {
const unsigned int *sinc5_data_rates;
unsigned int num_sinc5_data_rates;
unsigned int odr_start_value;
+ /*
+ * AD4116 has both inputs with a voltage divider and without.
+ * These inputs cannot be mixed in the channel configuration.
+ * Does not include the VINCOM input.
+ */
+ unsigned int num_voltage_in_div;
unsigned int num_channels;
unsigned int num_configs;
- unsigned int num_inputs;
+ unsigned int num_voltage_in;
unsigned int clock;
unsigned int id;
char *name;
+ bool has_current_inputs;
+ bool has_vincom_input;
bool has_temp;
/* ((AVDD1 − AVSS)/5) */
bool has_pow_supply_monitoring;
bool has_input_buf;
bool has_int_ref;
bool has_ref2;
+ bool higher_gpio_bits;
u8 num_gpios;
};

@@ -189,6 +215,24 @@ 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 */
@@ -204,10 +248,110 @@ static const unsigned int ad7175_sinc5_data_rates[] = {
5000, /* 20 */
};

+static unsigned int ad4111_current_channel_config[] = {
+ /* Ain sel: pos neg */
+ 0x1E8, /* 15:IIN0+ 8:IIN0− */
+ 0x1C9, /* 14:IIN1+ 9:IIN1− */
+ 0x1AA, /* 13:IIN2+ 10:IIN2− */
+ 0x18B, /* 12:IIN3+ 11:IIN3− */
+};
+
+static const struct ad7173_device_info ad4111_device_info = {
+ .name = "ad4111",
+ .id = AD4111_ID,
+ .num_voltage_in_div = 8,
+ .num_channels = 16,
+ .num_configs = 8,
+ .num_voltage_in = 8,
+ .num_gpios = 2,
+ .higher_gpio_bits = true,
+ .has_temp = true,
+ .has_vincom_input = 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),
+};
+
+static const struct ad7173_device_info ad4112_device_info = {
+ .name = "ad4112",
+ .id = AD4112_ID,
+ .num_voltage_in_div = 8,
+ .num_channels = 16,
+ .num_configs = 8,
+ .num_voltage_in = 8,
+ .num_gpios = 2,
+ .higher_gpio_bits = true,
+ .has_vincom_input = 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),
+};
+
+static const struct ad7173_device_info ad4114_device_info = {
+ .name = "ad4114",
+ .id = AD4114_ID,
+ .num_voltage_in_div = 16,
+ .num_channels = 16,
+ .num_configs = 8,
+ .num_voltage_in = 16,
+ .num_gpios = 4,
+ .higher_gpio_bits = true,
+ .has_vincom_input = 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),
+};
+
+static const struct ad7173_device_info ad4115_device_info = {
+ .name = "ad4115",
+ .id = AD4115_ID,
+ .num_voltage_in_div = 16,
+ .num_channels = 16,
+ .num_configs = 8,
+ .num_voltage_in = 16,
+ .num_gpios = 4,
+ .higher_gpio_bits = true,
+ .has_vincom_input = 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),
+};
+
+static const struct ad7173_device_info ad4116_device_info = {
+ .name = "ad4116",
+ .id = AD4116_ID,
+ .num_voltage_in_div = 11,
+ .num_channels = 16,
+ .num_configs = 8,
+ .num_voltage_in = 16,
+ .num_gpios = 4,
+ .higher_gpio_bits = true,
+ .has_vincom_input = 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),
+};
+
static const struct ad7173_device_info ad7172_2_device_info = {
.name = "ad7172-2",
.id = AD7172_2_ID,
- .num_inputs = 5,
+ .num_voltage_in = 5,
.num_channels = 4,
.num_configs = 4,
.num_gpios = 2,
@@ -223,7 +367,7 @@ static const struct ad7173_device_info ad7172_2_device_info = {
static const struct ad7173_device_info ad7172_4_device_info = {
.name = "ad7172-4",
.id = AD7172_4_ID,
- .num_inputs = 9,
+ .num_voltage_in = 9,
.num_channels = 8,
.num_configs = 8,
.num_gpios = 4,
@@ -238,7 +382,7 @@ static const struct ad7173_device_info ad7172_4_device_info = {
static const struct ad7173_device_info ad7173_8_device_info = {
.name = "ad7173-8",
.id = AD7173_ID,
- .num_inputs = 17,
+ .num_voltage_in = 17,
.num_channels = 16,
.num_configs = 8,
.num_gpios = 4,
@@ -254,7 +398,7 @@ static const struct ad7173_device_info ad7173_8_device_info = {
static const struct ad7173_device_info ad7175_2_device_info = {
.name = "ad7175-2",
.id = AD7175_2_ID,
- .num_inputs = 5,
+ .num_voltage_in = 5,
.num_channels = 4,
.num_configs = 4,
.num_gpios = 2,
@@ -270,7 +414,7 @@ static const struct ad7173_device_info ad7175_2_device_info = {
static const struct ad7173_device_info ad7175_8_device_info = {
.name = "ad7175-8",
.id = AD7175_8_ID,
- .num_inputs = 17,
+ .num_voltage_in = 17,
.num_channels = 16,
.num_configs = 8,
.num_gpios = 4,
@@ -287,7 +431,7 @@ static const struct ad7173_device_info ad7175_8_device_info = {
static const struct ad7173_device_info ad7176_2_device_info = {
.name = "ad7176-2",
.id = AD7176_ID,
- .num_inputs = 5,
+ .num_voltage_in = 5,
.num_channels = 4,
.num_configs = 4,
.num_gpios = 2,
@@ -300,7 +444,7 @@ static const struct ad7173_device_info ad7176_2_device_info = {
static const struct ad7173_device_info ad7177_2_device_info = {
.name = "ad7177-2",
.id = AD7177_ID,
- .num_inputs = 5,
+ .num_voltage_in = 5,
.num_channels = 4,
.num_configs = 4,
.num_gpios = 2,
@@ -353,6 +497,15 @@ static int ad7173_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
return 0;
}

+static int ad4111_mask_xlate(struct gpio_regmap *gpio, unsigned int base,
+ unsigned int offset, unsigned int *reg,
+ unsigned int *mask)
+{
+ *mask = AD4111_GPO01_DATA(offset);
+ *reg = base;
+ return 0;
+}
+
static void ad7173_gpio_disable(void *data)
{
struct ad7173_state *st = data;
@@ -385,7 +538,10 @@ static int ad7173_gpio_init(struct ad7173_state *st)
gpio_regmap.regmap = st->reg_gpiocon_regmap;
gpio_regmap.ngpio = st->info->num_gpios;
gpio_regmap.reg_set_base = AD7173_REG_GPIO;
- gpio_regmap.reg_mask_xlate = ad7173_mask_xlate;
+ if (st->info->higher_gpio_bits)
+ gpio_regmap.reg_mask_xlate = ad4111_mask_xlate;
+ else
+ gpio_regmap.reg_mask_xlate = ad7173_mask_xlate;

st->gpio_regmap = devm_gpio_regmap_register(dev, &gpio_regmap);
ret = PTR_ERR_OR_ZERO(st->gpio_regmap);
@@ -682,18 +838,33 @@ 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 {
+ return IIO_VAL_FRACTIONAL_LOG2;
+ 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_voltage_in_div)
+ *val *= AD4111_DIVIDER_RATIO;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ 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;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ 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;
@@ -702,10 +873,14 @@ static int ad7173_read_raw(struct iio_dev *indio_dev,
AD7173_VOLTAGE_INT_REF_uV *
MILLI);
*val = -temp;
- } else {
+ return IIO_VAL_INT;
+ case IIO_VOLTAGE:
+ case IIO_CURRENT:
*val = -BIT(chan->scan_type.realbits - 1);
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
}
- return IIO_VAL_INT;
case IIO_CHAN_INFO_SAMP_FREQ:
reg = st->channels[chan->address].cfg.odr;

@@ -927,6 +1102,23 @@ 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,
+ const unsigned int ain[AD7173_NO_AINS_PER_CHANNEL])
+{
+ struct device *dev = &st->sd.spi->dev;
+
+ if (!st->info->has_current_inputs)
+ return dev_err_probe(dev, -EINVAL,
+ "Model %s does not support current channels\n",
+ st->info->name);
+
+ if (ain[0] >= ARRAY_SIZE(ad4111_current_channel_config))
+ return dev_err_probe(dev, -EINVAL,
+ "For current channels single-channel must be <[0-3]>\n");
+
+ return 0;
+}
+
static int ad7173_validate_voltage_ain_inputs(struct ad7173_state *st,
unsigned int ain0, unsigned int ain1)
{
@@ -938,14 +1130,33 @@ static int ad7173_validate_voltage_ain_inputs(struct ad7173_state *st,
st->info->has_pow_supply_monitoring)
return 0;

- special_input0 = AD7173_IS_REF_INPUT(ain0);
- special_input1 = AD7173_IS_REF_INPUT(ain1);
+ special_input0 = AD7173_IS_REF_INPUT(ain0) ||
+ (ain0 == AD4111_VINCOM_INPUT && st->info->has_vincom_input);
+ special_input1 = AD7173_IS_REF_INPUT(ain1) ||
+ (ain1 == AD4111_VINCOM_INPUT && st->info->has_vincom_input);
+
+ if ((ain0 >= st->info->num_voltage_in && !special_input0) ||
+ (ain1 >= st->info->num_voltage_in && !special_input1)) {
+ if (ain0 == AD4111_VINCOM_INPUT || ain1 == AD4111_VINCOM_INPUT)
+ return dev_err_probe(dev, -EINVAL,
+ "VINCOM not supported for %s\n", st->info->name);

- if ((ain0 >= st->info->num_inputs && !special_input0) ||
- (ain1 >= st->info->num_inputs && !special_input1))
return dev_err_probe(dev, -EINVAL,
"Input pin number out of range for pair (%d %d).\n",
ain0, ain1);
+ }
+
+ if (AD4111_IS_VINCOM_MISMATCH(ain0, ain1) ||
+ AD4111_IS_VINCOM_MISMATCH(ain1, ain0))
+ return dev_err_probe(dev, -EINVAL,
+ "VINCOM must be paired with inputs having divider.\n");
+
+ if (!special_input0 && !special_input1 &&
+ ((ain0 >= st->info->num_voltage_in_div) !=
+ (ain1 >= st->info->num_voltage_in_div)))
+ return dev_err_probe(dev, -EINVAL,
+ "Both inputs must either have a voltage divider or not have: (%d %d).\n",
+ ain0, ain1);

return 0;
}
@@ -978,7 +1189,7 @@ 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[AD7173_NO_AINS_PER_CHANNEL], chan_index = 0;
- int ref_sel, ret, num_channels;
+ int ref_sel, ret, is_current_chan, num_channels;

num_channels = device_get_child_node_count(dev);

@@ -1025,15 +1236,38 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)

device_for_each_child_node_scoped(dev, child) {
chan = &chan_arr[chan_index];
+ *chan = ad7173_channel_template;
chan_st_priv = &chans_st_arr[chan_index];
ret = fwnode_property_read_u32_array(child, "diff-channels",
ain, ARRAY_SIZE(ain));
- if (ret)
- return ret;
+ if (ret) {
+ ret = fwnode_property_read_u32(child, "single-channel",
+ ain);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Channel must define one of diff-channels or single-channel.\n");

- ret = ad7173_validate_voltage_ain_inputs(st, ain[0], ain[1]);
- if (ret)
- return ret;
+ is_current_chan = fwnode_property_read_bool(child, "adi,current-channel");
+ } else {
+ chan->differential = true;
+ }
+
+ if (is_current_chan) {
+ ret = ad4111_validate_current_ain(st, ain);
+ if (ret)
+ return ret;
+ } else {
+ if (!chan->differential) {
+ ret = fwnode_property_read_u32(child,
+ "common-mode-channel", ain + 1);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "common-mode-channel must be defined for single-ended channels.\n");
+ }
+ ret = ad7173_validate_voltage_ain_inputs(st, ain[0], ain[1]);
+ if (ret)
+ return ret;
+ }

ret = fwnode_property_match_property_string(child,
"adi,reference-select",
@@ -1052,14 +1286,9 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
st->adc_mode |= AD7173_ADC_MODE_REF_EN;
chan_st_priv->cfg.ref_sel = ref_sel;

- *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]);
chan_st_priv->chan_reg = chan_index;
chan_st_priv->cfg.input_buf = st->info->has_input_buf;
chan_st_priv->cfg.odr = 0;
@@ -1068,6 +1297,17 @@ static int ad7173_fw_parse_channel_config(struct iio_dev *indio_dev)
if (chan_st_priv->cfg.bipolar)
chan->info_mask_separate |= BIT(IIO_CHAN_INFO_OFFSET);

+ if (is_current_chan) {
+ chan->type = IIO_CURRENT;
+ chan->differential = false;
+ chan->channel2 = 0;
+ chan_st_priv->ain = ad4111_current_channel_config[ain[0]];
+ } else {
+ chan_st_priv->cfg.input_buf = st->info->has_input_buf;
+ chan->channel2 = ain[1];
+ chan_st_priv->ain = AD7173_CH_ADDRESS(ain[0], ain[1]);
+ }
+
chan_index++;
}
return 0;
@@ -1194,6 +1434,11 @@ static int ad7173_probe(struct spi_device *spi)
}

static const struct of_device_id ad7173_of_match[] = {
+ { .compatible = "ad4111", .data = &ad4111_device_info },
+ { .compatible = "ad4112", .data = &ad4112_device_info },
+ { .compatible = "ad4114", .data = &ad4114_device_info },
+ { .compatible = "ad4115", .data = &ad4115_device_info },
+ { .compatible = "ad4116", .data = &ad4116_device_info },
{ .compatible = "adi,ad7172-2", .data = &ad7172_2_device_info },
{ .compatible = "adi,ad7172-4", .data = &ad7172_4_device_info },
{ .compatible = "adi,ad7173-8", .data = &ad7173_8_device_info },
@@ -1206,6 +1451,11 @@ 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)&ad4111_device_info },
+ { "ad4112", (kernel_ulong_t)&ad4112_device_info },
+ { "ad4114", (kernel_ulong_t)&ad4114_device_info },
+ { "ad4115", (kernel_ulong_t)&ad4115_device_info },
+ { "ad4116", (kernel_ulong_t)&ad4116_device_info },
{ "ad7172-2", (kernel_ulong_t)&ad7172_2_device_info },
{ "ad7172-4", (kernel_ulong_t)&ad7172_4_device_info },
{ "ad7173-8", (kernel_ulong_t)&ad7173_8_device_info },
@@ -1230,5 +1480,5 @@ 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 AD7173 and similar ADC driver");
MODULE_LICENSE("GPL");

--
2.43.0