* [PATCH v2 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04
2026-07-31 2:58 [PATCH v2 0/2] iio: adc: Add support for Texas Instruments ADS112C04 Kyle Hsieh
@ 2026-07-31 2:58 ` Kyle Hsieh
2026-07-31 4:32 ` Rob Herring (Arm)
2026-07-31 2:58 ` [PATCH v2 2/2] iio: adc: ti-ads112c04: Add support for TI ADS112C04 Kyle Hsieh
1 sibling, 1 reply; 5+ messages in thread
From: Kyle Hsieh @ 2026-07-31 2:58 UTC (permalink / raw)
To: Jonathan Cameron, David Lechner, Nuno Sá, Andy Shevchenko,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, Liam Girdwood,
Mark Brown
Cc: linux-iio, devicetree, linux-kernel, Kyle Hsieh
Add device tree binding documentation for Texas Instruments ADS112C04
I2C Analog-to-Digital Converters.
These devices provide 4-channel, 16-bit delta-sigma ADCs with an I2C
interface, programmable gain amplifier (PGA), and data-ready (DRDY)
interrupt output.
The binding uses child nodes to dynamically define the connected
single-ended or differential channels.
Signed-off-by: Kyle Hsieh <kylehsieh1995@gmail.com>
---
.../devicetree/bindings/iio/adc/ti,ads112c04.yaml | 122 +++++++++++++++++++++
1 file changed, 122 insertions(+)
diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
new file mode 100644
index 000000000000..6a5ffda84b80
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
@@ -0,0 +1,122 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/ti,ads112c04.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Texas Instruments ADS112C04 ADC
+
+maintainers:
+ - Kyle Hsieh <kylehsieh1995@gmail.com>
+
+description: |
+ The ADS112C04 (16-bit) are precision analog-to-digital converters (ADCs)
+ with an I2C interface. They feature a flexible input multiplexer, a
+ low-noise programmable gain amplifier (PGA), two programmable excitation
+ current sources, a voltage reference, and a precision temperature sensor.
+
+properties:
+ compatible:
+ enum:
+ - ti,ads112c04
+
+ reg:
+ maxItems: 1
+ description: I2C address of the device.
+
+ interrupts:
+ maxItems: 1
+ description: Data ready (DRDY) interrupt output.
+
+ "#address-cells":
+ const: 1
+
+ "#size-cells":
+ const: 0
+
+ reset-gpios:
+ maxItems: 1
+ description: GPIO connected to the RESET pin. Active low.
+
+ avdd-supply: true
+ dvdd-supply: true
+
+ refp-supply: true
+ refn-supply: true
+
+ ti,refp-refn-resistor-ohms:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description: Resistance of the external resistor between REFP and REFN.
+
+patternProperties:
+ "^channel@[0-9a-f]$":
+ $ref: adc.yaml
+ unevaluatedProperties: false
+ properties:
+ reg:
+ items:
+ - maximum: 15
+
+ single-channel:
+ maximum: 3
+
+ diff-channels:
+ items:
+ maximum: 3
+
+ oneOf:
+ - required: [ single-channel ]
+ - required: [ diff-channels ]
+
+required:
+ - compatible
+ - reg
+ - avdd-supply
+ - dvdd-supply
+
+dependencies:
+ refn-supply: [ refp-supply ]
+
+oneOf:
+ - required: [ refp-supply ]
+ - required: [ "ti,refp-refn-resistor-ohms" ]
+ - properties:
+ refp-supply: false
+ refn-supply: false
+ ti,refp-refn-resistor-ohms: false
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/interrupt-controller/irq.h>
+ #include <dt-bindings/gpio/gpio.h>
+ i2c {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ adc@40 {
+ compatible = "ti,ads112c04";
+ reg = <0x40>;
+ interrupt-parent = <&gpio>;
+ interrupts = <12 IRQ_TYPE_EDGE_FALLING>;
+
+ reset-gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
+ avdd-supply = <&vdd_3v3_reg>;
+ dvdd-supply = <&vdd_3v3_reg>;
+ refp-supply = <&vref_reg>;
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ channel@0 {
+ reg = <0>;
+ diff-channels = <0>, <1>;
+ };
+
+ channel@1 {
+ reg = <1>;
+ single-channel = <2>;
+ };
+ };
+ };
--
2.34.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v2 2/2] iio: adc: ti-ads112c04: Add support for TI ADS112C04
2026-07-31 2:58 [PATCH v2 0/2] iio: adc: Add support for Texas Instruments ADS112C04 Kyle Hsieh
2026-07-31 2:58 ` [PATCH v2 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04 Kyle Hsieh
@ 2026-07-31 2:58 ` Kyle Hsieh
2026-07-31 3:13 ` sashiko-bot
1 sibling, 1 reply; 5+ messages in thread
From: Kyle Hsieh @ 2026-07-31 2:58 UTC (permalink / raw)
To: Jonathan Cameron, David Lechner, Nuno Sá, Andy Shevchenko,
Rob Herring, Krzysztof Kozlowski, Conor Dooley, Liam Girdwood,
Mark Brown
Cc: linux-iio, devicetree, linux-kernel, Kyle Hsieh
Add IIO driver support for the Texas Instruments ADS112C04 (16-bit)
delta-sigma ADCs.
The driver implements:
- Single-shot conversions using the IIO raw read interface.
- Dynamic parsing of single-ended and differential channels from
device tree child nodes.
- Hardware interrupt support via the DRDY pin, falling back to
software polling if no IRQ is provided.
- Scale calculation based on the internal 2.048V reference.
- Dynamic reference voltage scaling via the regulator subsystem
(refp-supply/refn-supply), falling back to the internal 2.048V
reference if not specified.
- Hardware reset fallback using GPIO.
Signed-off-by: Kyle Hsieh <kylehsieh1995@gmail.com>
---
drivers/iio/adc/Kconfig | 10 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-ads112c04.c | 378 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 389 insertions(+)
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 3755a81c1efd..402e841bc083 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -1789,6 +1789,16 @@ config TI_ADS1119
This driver can also be built as a module. If so, the module will be
called ti-ads1119.
+config TI_ADS112C04
+ tristate "Texas Instruments ADS112C04 ADC"
+ depends on I2C
+ help
+ If you say yes here you get support for Texas Instruments
+ ADS112C04 (16-bit) I2C analog to digital converters.
+
+ This driver can also be built as a module. If so, the module will be
+ called ti-ads112c04.
+
config TI_ADS124S08
tristate "Texas Instruments ADS124S08"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 707dd708912f..ebf9d4047a5a 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -153,6 +153,7 @@ obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
obj-$(CONFIG_TI_ADS1018) += ti-ads1018.o
obj-$(CONFIG_TI_ADS1100) += ti-ads1100.o
obj-$(CONFIG_TI_ADS1119) += ti-ads1119.o
+obj-$(CONFIG_TI_ADS112C04) += ti-ads112c04.o
obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o
obj-$(CONFIG_TI_ADS1298) += ti-ads1298.o
obj-$(CONFIG_TI_ADS131E08) += ti-ads131e08.o
diff --git a/drivers/iio/adc/ti-ads112c04.c b/drivers/iio/adc/ti-ads112c04.c
new file mode 100644
index 000000000000..28d3be81934f
--- /dev/null
+++ b/drivers/iio/adc/ti-ads112c04.c
@@ -0,0 +1,378 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Texas Instruments ADS112C04 16-bit I2C ADC driver
+ * Based on TI Reference Code and standard Linux IIO framework.
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/regulator/consumer.h>
+#include <linux/bitfield.h>
+#include <linux/iopoll.h>
+#include <linux/property.h>
+#include <linux/gpio/consumer.h>
+
+/* ADS112C04 Commands */
+#define ADS112C04_CMD_RESET 0x06
+#define ADS112C04_CMD_START_SYNC 0x08
+#define ADS112C04_CMD_POWERDOWN 0x02
+#define ADS112C04_CMD_RDATA 0x10
+#define ADS112C04_CMD_RREG(reg) (0x20 | ((reg) << 2))
+#define ADS112C04_CMD_WREG(reg) (0x40 | ((reg) << 2))
+
+/* Registers */
+#define ADS112C04_REG_CONFIG0 0x00
+#define ADS112C04_REG_CONFIG1 0x01
+#define ADS112C04_REG_CONFIG2 0x02
+#define ADS112C04_REG_CONFIG3 0x03
+
+#define ADS112C04_DRDY_MASK BIT(7)
+#define ADS112C04_MUX_MASK GENMASK(7, 4)
+
+struct ads112c04_state {
+ struct i2c_client *client;
+ /* Protects concurrent ADC reads and device configuration */
+ struct mutex lock;
+ struct completion completion;
+ struct regulator *vref_reg;
+ int vref_mv;
+ u8 config0;
+ u8 config1;
+};
+
+static int ads112c04_write_cmd(struct i2c_client *client, u8 cmd)
+{
+ int ret = i2c_master_send(client, &cmd, 1);
+
+ return ret < 0 ? ret : 0;
+}
+
+static int ads112c04_read_reg(struct i2c_client *client, u8 reg, u8 *val)
+{
+ u8 cmd = ADS112C04_CMD_RREG(reg);
+ int ret;
+
+ ret = i2c_master_send(client, &cmd, 1);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_master_recv(client, val, 1);
+ return ret < 0 ? ret : 0;
+}
+
+static int ads112c04_write_reg(struct i2c_client *client, u8 reg, u8 val)
+{
+ u8 buf[2] = { ADS112C04_CMD_WREG(reg), val };
+ int ret;
+
+ ret = i2c_master_send(client, buf, 2);
+ return ret < 0 ? ret : 0;
+}
+
+static int ads112c04_wait_for_data(struct ads112c04_state *st)
+{
+ int ret;
+ u8 val;
+
+ if (st->client->irq > 0) {
+ ret = wait_for_completion_timeout(&st->completion, msecs_to_jiffies(1000));
+ if (!ret)
+ return -ETIMEDOUT;
+ return 0;
+ }
+
+ return read_poll_timeout(ads112c04_read_reg, ret,
+ (ret < 0 || (val & ADS112C04_DRDY_MASK)),
+ 1000, 1000000, false,
+ st->client, ADS112C04_REG_CONFIG2, &val);
+}
+
+static int ads112c04_read_data(struct ads112c04_state *st, int *val)
+{
+ u8 cmd = ADS112C04_CMD_RDATA;
+ __be16 buf;
+ int ret;
+
+ ret = i2c_master_send(st->client, &cmd, 1);
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_master_recv(st->client, (u8 *)&buf, 2);
+ if (ret < 0)
+ return ret;
+
+ *val = sign_extend32(be16_to_cpu(buf), 15);
+ return 0;
+}
+
+static int ads112c04_get_adc_result(struct ads112c04_state *st,
+ struct iio_chan_spec const *chan,
+ int *val)
+{
+ int ret;
+ u8 mux, new_config0;
+
+ mux = FIELD_PREP(ADS112C04_MUX_MASK, chan->address);
+ new_config0 = (st->config0 & 0x0F) | mux;
+
+ if (st->config0 != new_config0) {
+ ret = ads112c04_write_reg(st->client, ADS112C04_REG_CONFIG0, new_config0);
+ if (ret < 0)
+ return ret;
+ st->config0 = new_config0;
+ }
+
+ reinit_completion(&st->completion);
+
+ ret = ads112c04_write_cmd(st->client, ADS112C04_CMD_START_SYNC);
+ if (ret < 0)
+ return ret;
+
+ ret = ads112c04_wait_for_data(st);
+ if (ret < 0)
+ return ret;
+
+ return ads112c04_read_data(st, val);
+}
+
+static int ads112c04_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct ads112c04_state *st = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&st->lock);
+ ret = ads112c04_get_adc_result(st, chan, val);
+ mutex_unlock(&st->lock);
+
+ if (ret < 0)
+ return ret;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ *val = st->vref_mv;
+ *val2 = 15;
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static irqreturn_t ads112c04_irq_handler(int irq, void *private)
+{
+ struct iio_dev *indio_dev = private;
+ struct ads112c04_state *st = iio_priv(indio_dev);
+
+ complete(&st->completion);
+
+ return IRQ_HANDLED;
+}
+
+static const struct iio_info ads112c04_info = {
+ .read_raw = ads112c04_read_raw,
+};
+
+static void ads112c04_regulator_disable(void *data)
+{
+ regulator_disable(data);
+}
+
+static int ads112c04_parse_channels(struct iio_dev *indio_dev)
+{
+ struct device *dev = indio_dev->dev.parent;
+ struct iio_chan_spec *channels;
+ u32 num_channels, i = 0, pair[2];
+
+ num_channels = device_get_named_child_node_count(dev, "channel");
+ if (!num_channels)
+ return -EINVAL;
+
+ channels = devm_kcalloc(dev, num_channels, sizeof(*channels), GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ device_for_each_named_child_node_scoped(dev, child, "channel") {
+ struct iio_chan_spec *spec = &channels[i];
+
+ spec->type = IIO_VOLTAGE;
+ spec->indexed = 1;
+ spec->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE);
+ spec->scan_index = i;
+
+ if (fwnode_property_present(child, "single-channel")) {
+ fwnode_property_read_u32(child, "single-channel", &pair[0]);
+ spec->channel = pair[0];
+ spec->differential = 0;
+ spec->address = 0x08 + pair[0];
+ } else if (fwnode_property_present(child, "diff-channels")) {
+ fwnode_property_read_u32_array(child, "diff-channels", pair, 2);
+ spec->channel = pair[0];
+ spec->channel2 = pair[1];
+ spec->differential = 1;
+
+ if (pair[0] == 0 && pair[1] == 1)
+ spec->address = 0x00;
+ else if (pair[0] == 0 && pair[1] == 2)
+ spec->address = 0x01;
+ else if (pair[0] == 0 && pair[1] == 3)
+ spec->address = 0x02;
+ else if (pair[0] == 1 && pair[1] == 0)
+ spec->address = 0x03;
+ else if (pair[0] == 1 && pair[1] == 2)
+ spec->address = 0x04;
+ else if (pair[0] == 1 && pair[1] == 3)
+ spec->address = 0x05;
+ else if (pair[0] == 2 && pair[1] == 3)
+ spec->address = 0x06;
+ else if (pair[0] == 3 && pair[1] == 2)
+ spec->address = 0x07;
+ else
+ return -EINVAL;
+ } else {
+ return -EINVAL;
+ }
+ i++;
+ }
+
+ indio_dev->channels = channels;
+ indio_dev->num_channels = num_channels;
+
+ return 0;
+}
+
+static int ads112c04_probe(struct i2c_client *client)
+{
+ struct iio_dev *indio_dev;
+ struct ads112c04_state *st;
+ struct gpio_desc *reset_gpio;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ st->client = client;
+
+ ret = devm_mutex_init(&client->dev, &st->lock);
+ if (ret)
+ return ret;
+
+ init_completion(&st->completion);
+
+ indio_dev->name = "ads112c04";
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &ads112c04_info;
+
+ ret = ads112c04_parse_channels(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = devm_regulator_get_enable(&client->dev, "avdd");
+ if (ret)
+ return dev_err_probe(&client->dev, ret, "failed to get avdd regulator\n");
+
+ ret = devm_regulator_get_enable(&client->dev, "dvdd");
+ if (ret)
+ return dev_err_probe(&client->dev, ret, "failed to get dvdd regulator\n");
+
+ st->vref_reg = devm_regulator_get_optional(&client->dev, "refp");
+ if (IS_ERR(st->vref_reg)) {
+ ret = PTR_ERR(st->vref_reg);
+ if (ret == -ENODEV) {
+ st->vref_mv = 2048;
+ st->config1 = 0x00;
+ } else {
+ return ret;
+ }
+ } else {
+ ret = regulator_enable(st->vref_reg);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(&client->dev, ads112c04_regulator_disable,
+ st->vref_reg);
+ if (ret)
+ return ret;
+
+ ret = regulator_get_voltage(st->vref_reg);
+ if (ret < 0)
+ return ret;
+
+ st->vref_mv = ret / 1000;
+ st->config1 = 0x02;
+ }
+
+ reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(reset_gpio))
+ return PTR_ERR(reset_gpio);
+
+ if (reset_gpio) {
+ gpiod_set_value_cansleep(reset_gpio, 1);
+ fsleep(1000);
+ gpiod_set_value_cansleep(reset_gpio, 0);
+ } else {
+ ret = ads112c04_write_cmd(client, ADS112C04_CMD_RESET);
+ if (ret < 0)
+ return ret;
+ }
+
+ fsleep(1000);
+
+ st->config0 = 0x01;
+ ret = ads112c04_write_reg(client, ADS112C04_REG_CONFIG0, st->config0);
+ if (ret)
+ return ret;
+
+ ret = ads112c04_write_reg(client, ADS112C04_REG_CONFIG1, st->config1);
+ if (ret)
+ return ret;
+
+ if (client->irq > 0) {
+ ret = devm_request_irq(&client->dev, client->irq,
+ ads112c04_irq_handler,
+ 0,
+ indio_dev->name, indio_dev);
+ if (ret) {
+ dev_err(&client->dev, "Failed to request DRDY IRQ\n");
+ return ret;
+ }
+ }
+
+ return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static const struct i2c_device_id ads112c04_id[] = {
+ { .name = "ads112c04", .driver_data = 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ads112c04_id);
+
+static const struct of_device_id ads112c04_of_match[] = {
+ { .compatible = "ti,ads112c04" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ads112c04_of_match);
+
+static struct i2c_driver ads112c04_driver = {
+ .driver = {
+ .name = "ads112c04",
+ .of_match_table = ads112c04_of_match,
+ },
+ .probe = ads112c04_probe,
+ .id_table = ads112c04_id,
+};
+module_i2c_driver(ads112c04_driver);
+
+MODULE_AUTHOR("Kyle Hsieh <kylehsieh1995@gmail.com>");
+MODULE_DESCRIPTION("Texas Instruments ADS112C04 ADC driver");
+MODULE_LICENSE("GPL");
--
2.34.1
^ permalink raw reply related [flat|nested] 5+ messages in thread