* [PATCH v5 0/2] iio: adc: Add support for Texas Instruments ADS112C04
@ 2026-08-13 3:06 Kyle Hsieh
2026-08-13 3:06 ` [PATCH v5 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04 Kyle Hsieh
2026-08-13 3:06 ` [PATCH v5 2/2] iio: adc: ti-ads112c04: Add support for TI ADS112C04 Kyle Hsieh
0 siblings, 2 replies; 6+ messages in thread
From: Kyle Hsieh @ 2026-08-13 3:06 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, Conor Dooley
This patch series introduces support for the Texas Instruments ADS112C04
Analog-to-Digital Converters.
The ADS112C04 (16-bit) is precision, low-power, delta-sigma ADCs with
an I2C interface. They feature a flexible input multiplexer supporting
single-ended and differential measurements, a programmable gain amplifier,
and an internal voltage reference.
Note: While this chip shares similarities with the ADS112C14 (currently
being upstreamed by David Lechner), the register maps and feature sets
are sufficiently different to warrant a separate driver. However, the
DT bindings and channel parsing logic have been aligned with the
ADS112C14 conventions.
This initial submission provides a minimal feature set (single-shot
conversions and basic DRDY interrupt) covering current use cases.
Signed-off-by: Kyle Hsieh <kylehsieh1995@gmail.com>
---
Changes in v5:
- Addressed several suggestions from v1-v4 that I had missed in earlier
revisions. Apologies for the churn this caused; I went back through
all four threads as David asked.
- dt-bindings: iio: adc: ti,ads112c04:
- No changes. Picked up David's Reviewed-by and Conor's Acked-by.
- iio: adc: ti-ads112c04:
- Made the reference voltage per-channel, following the ADS112C14
driver: reference-sources is parsed with
fwnode_property_match_property_string() and stored per channel, and
the CONFIG1 VREF field is now updated together with the MUX before
each conversion. avdd is read with
devm_regulator_get_enable_read_voltage() when a channel uses it.
- Organised the register field macros indented under their register,
and shortened CONFIG to CONF in the field names.
- Spelled out all CONFIG0/CONFIG1 fields explicitly with FIELD_PREP()
when initialising, rather than relying on implicit zeros.
- Moved the internal reference macro to the top of the file with the
other defines and renamed it to ADS112C04_INT_REF_mV.
- Dropped disable_irq_nosync(); the handler only calls complete(),
which is safe in a normal IRQ handler, so a threaded IRQ isn't
needed. The bare `0` flags argument is now packed with the
other arguments.
- Fixed word-read byte ordering by using
i2c_smbus_read_word_swapped().
- Dropped the has_refp state member; it is passed as a function
argument instead.
- Added a REVISIT comment on spec->type for when
ti,refp-refn-resistor-ohms is implemented.
- Reduced the power-on reset delay from 50ms to 500us, per the
datasheet.
- Replaced the diff-channels if-else chain with a 4x4 lookup table
indexed by [AINP][AINN].
- Used wait_for_completion_timeout() directly in the if condition,
swapped err/ret in ads112c04_wait_for_data(), made the channel
index unsigned int with the assignment split out, stopped reusing
pair[0] for single-channel, and used ARRAY_SIZE(pair).
- Added ADS112C04_MAX_CHANNELS and used it in the bounds check.
- Split reference-sources parsing into a helper to keep the call
within the line length limit.
- Updated the commit message to describe per-channel reference
selection; refn-supply remains unsupported.
- Switched the hardware reset to the reset controller framework
(devm_reset_control_get_optional_exclusive()), which works with the
existing reset-gpios property via the reset-gpio driver. The binding
is unchanged.
- Link to v4: https://lore.kernel.org/r/20260811-ti-ads112c04-driver-v4-0-ae704ac17241@gmail.com
Changes in v4:
- dt-bindings: iio: adc: ti,ads112c04:
- Fixed excitation-current-nanoamp to use single-entry list syntax
(items: - enum: [...]) instead of combining maxItems: 1 with a
mapping-style items, which failed dt_binding_check.
- Widened excitation-channels to maximum: 5 to account for IDAC1/
IDAC2 also being routable to REFP0/REFN0, and documented the
mapping, per David Lechner.
- Reduced excitation-current-nanoamp to a single entry, since the
two IDAC outputs share one current setting, per David Lechner.
- Changed burn-out-current-nanoamp to use `const: 10000`, per David
Lechner.
- Renamed reference-sources' internal enum value to "internal"
(dropped voltage suffix, since there is only one internal
reference), per David Lechner.
- iio: adc: ti-ads112c04:
- Fixed word-read byte ordering by switching to
i2c_smbus_read_word_swapped(), addressing a big-endian data
corruption issue flagged by Sashiko AI review.
- Masked the DRDY interrupt in the hardirq handler
(disable_irq_nosync()) and re-enabled it once the conversion data
is read, to avoid an interrupt storm on level-triggered DRDY
configurations, without hardcoding the trigger type.
- Reworked reference-sources handling in parse_channels(): it is now
validated against the actually-selected refp-supply instead of
being unconditionally rejected, per David Lechner.
- Simplified regulator handling in probe() using
devm_regulator_get_enable_read_voltage(), dropping the now-unused
vref_reg field, per David Lechner.
- Corrected the commit message to no longer claim refn-supply
support, since it remains explicitly unsupported in probe().
- Added a MAINTAINERS entry for the new binding and driver.
- Link to v3: https://lore.kernel.org/r/20260805-ti-ads112c04-driver-v3-0-49f436829e01@gmail.com
Changes in v3:
- dt-bindings: iio: adc: ti,ads112c04:
- Resolved dt_binding_check errors by removing redundant $ref for
standard unit suffixes and fixing YAML array syntax.
- Added full hardware capability descriptions (excitation-channels,
excitation-current-nanoamp, burn-out-current-nanoamp,
reference-sources) as suggested by David Lechner.
- Restricted the reg maximum to 11 and updated the regex to
^channel@[0-9a-b]$ to accurately reflect the 12 possible MUX
combinations.
- iio: adc: ti-ads112c04:
- Transitioned all I2C read/write wrappers to use SMBus APIs
(i2c_smbus_read_byte_data, i2c_smbus_read_word_data, etc.) to
gracefully handle I2C errors, NACKs, and Repeated Starts, addressing
feedback from Joshua Crofts and Jonathan Cameron.
- Added forward compatibility checks in probe() and parse_channels()
using dev_err_probe() to return -EOPNOTSUPP for unimplemented DT
properties.
- Reverted devm_request_irq() flags to 0 to let the driver inherit the
trigger type strictly from the DT, per Jonathan Cameron's advice.
- Reduced the data wait timeout to 100ms, reflecting the chip's slowest
data rate of 20 SPS.
- Fixed #include alphabetical sorting, grouped <linux/iio/*> headers,
and added missing headers.
- Fixed variable declaration ordering (reverse xmas tree) and updated
variable naming to vref_mV (SI unit exception).
- Optimized GPIO reset logic using GPIOD_OUT_HIGH.
- Link to v2: https://lore.kernel.org/r/20260731-ti-ads112c04-driver-v2-0-aab0168c3c01@gmail.com
Changes in v2:
- Replaced `vref-supply` with `refp-supply` and `refn-supply` to accurately reflect hardware.
- Refactored the driver to dynamically parse channel configurations and routing from DT child nodes.
- Modernized the driver using kernel macros.
- Handled endianness elegantly.
- Added hardware reset fallback logic.
- Inherited IRQ trigger type from device tree instead of hardcoding.
- Fixed a bug where the MUX software cache could desync from hardware if the I2C write failed.
- Added strict return value checking for all I2C writes during probe.
- Updated the `i2c_device_id` array to use C99 named initializers.
- Link to v1: https://lore.kernel.org/r/20260728-ti-ads112c04-driver-v1-0-475efe4e2b78@gmail.com
---
Kyle Hsieh (2):
dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04
iio: adc: ti-ads112c04: Add support for TI ADS112C04
.../devicetree/bindings/iio/adc/ti,ads112c04.yaml | 148 ++++++
MAINTAINERS | 7 +
drivers/iio/adc/Kconfig | 10 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-ads112c04.c | 525 +++++++++++++++++++++
5 files changed, 691 insertions(+)
---
base-commit: 350d1fb9204b13c5f95e511e98b8bcb47574d425
change-id: 20260724-ti-ads112c04-driver-be7e89047834
Best regards,
--
Kyle Hsieh <kylehsieh1995@gmail.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v5 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04
2026-08-13 3:06 [PATCH v5 0/2] iio: adc: Add support for Texas Instruments ADS112C04 Kyle Hsieh
@ 2026-08-13 3:06 ` Kyle Hsieh
2026-08-13 3:10 ` sashiko-bot
2026-08-13 16:57 ` Rob Herring
2026-08-13 3:06 ` [PATCH v5 2/2] iio: adc: ti-ads112c04: Add support for TI ADS112C04 Kyle Hsieh
1 sibling, 2 replies; 6+ messages in thread
From: Kyle Hsieh @ 2026-08-13 3:06 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, Conor Dooley
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.
Excitation current, burn-out current, and reference source properties
are also included to fully describe the chip's hardware capabilities,
aligned with the ti,ads112c14 binding conventions.
Reviewed-by: David Lechner <dlechner@baylibre.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Kyle Hsieh <kylehsieh1995@gmail.com>
---
.../devicetree/bindings/iio/adc/ti,ads112c04.yaml | 148 +++++++++++++++++++++
MAINTAINERS | 6 +
2 files changed, 154 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..68a0df21cedd
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
@@ -0,0 +1,148 @@
+# 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:
+ description: Resistance of the external resistor between REFP and REFN.
+
+patternProperties:
+ "^channel@[0-9a-b]$":
+ $ref: adc.yaml
+ unevaluatedProperties: false
+ properties:
+ reg:
+ items:
+ - maximum: 11
+
+ single-channel:
+ maximum: 3
+
+ diff-channels:
+ items:
+ maximum: 3
+
+ excitation-channels:
+ maxItems: 2
+ items:
+ maximum: 5
+ description:
+ Additionally to AIN0-AIN3, IDAC1/IDAC2 can also be routed to
+ REFP0 (4) and REFN0 (5).
+
+ excitation-current-nanoamp:
+ items:
+ - enum: [10000, 50000, 100000, 250000, 500000, 1000000, 1500000]
+
+ burn-out-current-nanoamp:
+ items:
+ - const: 10000
+
+ reference-sources:
+ items:
+ - enum: [internal, external, avdd]
+ default: internal
+
+ dependencies:
+ excitation-channels: [ excitation-current-nanoamp ]
+ excitation-current-nanoamp: [ excitation-channels ]
+
+ 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>;
+ };
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 04fa5322d9f7..417d74b6d6cc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -26987,6 +26987,12 @@ S: Maintained
F: Documentation/devicetree/bindings/iio/adc/ti,ads1119.yaml
F: drivers/iio/adc/ti-ads1119.c
+TI ADS112C04 ADC DRIVER
+M: Kyle Hsieh <kylehsieh1995@gmail.com>
+L: linux-iio@vger.kernel.org
+S: Maintained
+F: Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
+
TI ADS112C14 ADC DRIVER
M: David Lechner <dlechner@baylibre.com>
L: linux-iio@vger.kernel.org
--
2.34.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v5 2/2] iio: adc: ti-ads112c04: Add support for TI ADS112C04
2026-08-13 3:06 [PATCH v5 0/2] iio: adc: Add support for Texas Instruments ADS112C04 Kyle Hsieh
2026-08-13 3:06 ` [PATCH v5 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04 Kyle Hsieh
@ 2026-08-13 3:06 ` Kyle Hsieh
2026-08-13 3:14 ` sashiko-bot
1 sibling, 1 reply; 6+ messages in thread
From: Kyle Hsieh @ 2026-08-13 3:06 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.
- Per-channel reference source selection (internal 2.048V, external
REFP/REFN, or AVDD) via the reference-sources device tree property.
refn-supply is not yet supported.
- Hardware reset via the reset controller framework, falling back to
the RESET command when no reset controller is present.
Signed-off-by: Kyle Hsieh <kylehsieh1995@gmail.com>
---
MAINTAINERS | 1 +
drivers/iio/adc/Kconfig | 10 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ti-ads112c04.c | 525 +++++++++++++++++++++++++++++++++++++++++
4 files changed, 537 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 417d74b6d6cc..f51fbda9d4b9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -26992,6 +26992,7 @@ M: Kyle Hsieh <kylehsieh1995@gmail.com>
L: linux-iio@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
+F: drivers/iio/adc/ti-ads112c04.c
TI ADS112C14 ADC DRIVER
M: David Lechner <dlechner@baylibre.com>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 990e7b3e7212..037fc7df8415 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -1817,6 +1817,16 @@ 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_ADS112C14
tristate "Texas Instruments ADS112C14/ADS122C14"
depends on I2C
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index dcec0abb03b7..d8acf2831fd2 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -155,6 +155,7 @@ 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-$(CONFIG_TI_ADS112C14) += ti-ads112c14.o
obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o
obj-$(CONFIG_TI_ADS1298) += ti-ads1298.o
diff --git a/drivers/iio/adc/ti-ads112c04.c b/drivers/iio/adc/ti-ads112c04.c
new file mode 100644
index 000000000000..c2995e94c4f8
--- /dev/null
+++ b/drivers/iio/adc/ti-ads112c04.c
@@ -0,0 +1,525 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Texas Instruments ADS112C04 16-bit I2C ADC driver
+ *
+ * Copyright (c) 2026 Kyle Hsieh <kylehsieh1995@gmail.com>
+ *
+ * Datasheet: https://www.ti.com/lit/ds/symlink/ads112c04.pdf
+ * Based on TI Reference Code and standard Linux IIO framework.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/types.h>
+#include <linux/units.h>
+
+#include <linux/iio/iio.h>
+
+#define ADS112C04_CMD_RESET 0x06
+#define ADS112C04_CMD_START_SYNC 0x08
+#define ADS112C04_CMD_RDATA 0x10
+#define ADS112C04_CMD_RREG(reg) (0x20 | ((reg) << 2))
+#define ADS112C04_CMD_WREG(reg) (0x40 | ((reg) << 2))
+
+#define ADS112C04_REG_CONFIG0 0x00
+#define ADS112C04_CONF0_MUX GENMASK(7, 4)
+#define ADS112C04_CONF0_MUX_AIN0_AIN1 0
+#define ADS112C04_CONF0_MUX_AIN_SINGLE_BASE 8
+#define ADS112C04_CONF0_GAIN GENMASK(3, 1)
+#define ADS112C04_CONF0_GAIN_X1 0
+#define ADS112C04_CONF0_PGA_BYPASS BIT(0)
+
+#define ADS112C04_REG_CONFIG1 0x01
+#define ADS112C04_CONF1_DR GENMASK(7, 5)
+#define ADS112C04_CONF1_DR_20SPS 0
+#define ADS112C04_CONF1_MODE BIT(4)
+#define ADS112C04_CONF1_MODE_NORMAL 0
+#define ADS112C04_CONF1_CM BIT(3)
+#define ADS112C04_CONF1_CM_SINGLE_SHOT 0
+#define ADS112C04_CONF1_VREF GENMASK(2, 1)
+#define ADS112C04_CONF1_VREF_INTERNAL 0
+#define ADS112C04_CONF1_VREF_EXTERNAL 1
+#define ADS112C04_CONF1_VREF_AVDD 2
+#define ADS112C04_CONF1_TS BIT(0)
+#define ADS112C04_CONF1_TS_DISABLED 0
+
+#define ADS112C04_REG_CONFIG2 0x02
+#define ADS112C04_CONF2_DRDY BIT(7)
+
+#define ADS112C04_INT_REF_mV 2048
+
+#define ADS112C04_MAX_CHANNELS 12
+
+enum {
+ ADS112C04_VREF_SOURCE_INTERNAL,
+ ADS112C04_VREF_SOURCE_EXTERNAL,
+ ADS112C04_VREF_SOURCE_AVDD,
+};
+
+static const char * const ads112c04_vref_names[] = {
+ [ADS112C04_VREF_SOURCE_INTERNAL] = "internal",
+ [ADS112C04_VREF_SOURCE_EXTERNAL] = "external",
+ [ADS112C04_VREF_SOURCE_AVDD] = "avdd",
+};
+
+static const u8 ads112c04_vref_reg_val[] = {
+ [ADS112C04_VREF_SOURCE_INTERNAL] = ADS112C04_CONF1_VREF_INTERNAL,
+ [ADS112C04_VREF_SOURCE_EXTERNAL] = ADS112C04_CONF1_VREF_EXTERNAL,
+ [ADS112C04_VREF_SOURCE_AVDD] = ADS112C04_CONF1_VREF_AVDD,
+};
+
+/* Indexed by [AINP][AINN], -1 means the combination is not available. */
+static const s8 ads112c04_diff_mux[4][4] = {
+ { -1, 0, 1, 2 },
+ { 3, -1, 4, 5 },
+ { -1, -1, -1, 6 },
+ { -1, -1, 7, -1 },
+};
+
+struct ads112c04_state {
+ struct i2c_client *client;
+ /* Protects concurrent ADC reads and device configuration */
+ struct mutex lock;
+ struct completion completion;
+ u32 avdd_mV;
+ u32 ext_ref_mV;
+ u8 *vref_source; /* one entry per channel, indexed by scan order */
+ u8 config0;
+ u8 config1;
+};
+
+static int ads112c04_write_cmd(struct i2c_client *client, u8 cmd)
+{
+ return i2c_smbus_write_byte(client, cmd);
+}
+
+static int ads112c04_read_reg(struct i2c_client *client, u8 reg, u8 *val)
+{
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(client, ADS112C04_CMD_RREG(reg));
+ if (ret < 0)
+ return ret;
+
+ *val = ret;
+
+ return 0;
+}
+
+static int ads112c04_write_reg(struct i2c_client *client, u8 reg, u8 val)
+{
+ return i2c_smbus_write_byte_data(client, ADS112C04_CMD_WREG(reg), val);
+}
+
+static int ads112c04_wait_for_data(struct ads112c04_state *st)
+{
+ int ret, err;
+ u8 val;
+
+ if (st->client->irq > 0) {
+ /* Timeout is 100ms (slowest data rate is 20 SPS) */
+ if (!wait_for_completion_timeout(&st->completion, msecs_to_jiffies(100)))
+ return -ETIMEDOUT;
+
+ return 0;
+ }
+
+ ret = read_poll_timeout(ads112c04_read_reg, err,
+ (err < 0 || (val & ADS112C04_CONF2_DRDY)),
+ 1 * USEC_PER_MSEC, 100 * USEC_PER_MSEC, false,
+ st->client, ADS112C04_REG_CONFIG2, &val);
+ if (err < 0)
+ return err;
+
+ return ret;
+}
+
+static int ads112c04_read_data(struct ads112c04_state *st, int *val)
+{
+ int ret;
+
+ ret = i2c_smbus_read_word_swapped(st->client, ADS112C04_CMD_RDATA);
+ if (ret < 0)
+ return ret;
+
+ *val = sign_extend32(ret, 15);
+
+ return 0;
+}
+
+static int ads112c04_get_adc_result(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val)
+{
+ struct ads112c04_state *st = iio_priv(indio_dev);
+ unsigned int idx = chan - indio_dev->channels;
+ u8 new_config0, new_config1;
+ int ret;
+
+ new_config0 = st->config0;
+ FIELD_MODIFY(ADS112C04_CONF0_MUX, &new_config0, chan->address);
+
+ 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;
+ }
+
+ new_config1 = st->config1;
+ FIELD_MODIFY(ADS112C04_CONF1_VREF, &new_config1,
+ ads112c04_vref_reg_val[st->vref_source[idx]]);
+
+ if (st->config1 != new_config1) {
+ ret = ads112c04_write_reg(st->client, ADS112C04_REG_CONFIG1,
+ new_config1);
+ if (ret < 0)
+ return ret;
+
+ st->config1 = new_config1;
+ }
+
+ 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);
+ unsigned int idx = chan - indio_dev->channels;
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ mutex_lock(&st->lock);
+ ret = ads112c04_get_adc_result(indio_dev, chan, val);
+ mutex_unlock(&st->lock);
+
+ if (ret < 0)
+ return ret;
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ switch (st->vref_source[idx]) {
+ case ADS112C04_VREF_SOURCE_EXTERNAL:
+ *val = st->ext_ref_mV;
+ break;
+ case ADS112C04_VREF_SOURCE_AVDD:
+ *val = st->avdd_mV;
+ break;
+ default:
+ *val = ADS112C04_INT_REF_mV;
+ break;
+ }
+ *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 int ads112c04_parse_vref_source(struct fwnode_handle *child)
+{
+ if (!fwnode_property_present(child, "reference-sources"))
+ return ADS112C04_VREF_SOURCE_INTERNAL;
+
+ return fwnode_property_match_property_string(child, "reference-sources",
+ ads112c04_vref_names,
+ ARRAY_SIZE(ads112c04_vref_names));
+}
+
+static int ads112c04_parse_channels(struct iio_dev *indio_dev,
+ bool *need_avdd_ref, bool *need_ext_ref)
+{
+ struct device *dev = indio_dev->dev.parent;
+ struct ads112c04_state *st = iio_priv(indio_dev);
+ struct iio_chan_spec *channels;
+ u32 num_channels, pair[2], channel;
+ unsigned int i;
+ int ret;
+
+ num_channels = device_get_named_child_node_count(dev, "channel");
+ if (!num_channels)
+ return dev_err_probe(dev, -EINVAL, "no channel subnodes found\n");
+
+ if (num_channels > ADS112C04_MAX_CHANNELS)
+ return dev_err_probe(dev, -EINVAL,
+ "num of channel nodes exceeds %d\n",
+ ADS112C04_MAX_CHANNELS);
+
+ channels = devm_kcalloc(dev, num_channels, sizeof(*channels), GFP_KERNEL);
+ if (!channels)
+ return -ENOMEM;
+
+ st->vref_source = devm_kcalloc(dev, num_channels,
+ sizeof(*st->vref_source), GFP_KERNEL);
+ if (!st->vref_source)
+ return -ENOMEM;
+
+ i = 0;
+ device_for_each_named_child_node_scoped(dev, child, "channel") {
+ struct iio_chan_spec *spec = &channels[i];
+
+ if (fwnode_property_present(child, "excitation-channels"))
+ return dev_err_probe(dev, -EOPNOTSUPP,
+ "excitation-channels is not supported yet\n");
+
+ st->vref_source[i] = ADS112C04_VREF_SOURCE_INTERNAL;
+
+ if (fwnode_property_present(child, "reference-sources")) {
+ ret = ads112c04_parse_vref_source(child);
+ if (ret < 0)
+ return dev_err_probe(dev, ret,
+ "invalid reference-sources value\n");
+
+ st->vref_source[i] = ret;
+ }
+
+ if (st->vref_source[i] == ADS112C04_VREF_SOURCE_EXTERNAL)
+ *need_ext_ref = true;
+ if (st->vref_source[i] == ADS112C04_VREF_SOURCE_AVDD)
+ *need_avdd_ref = true;
+
+ /*
+ * REVISIT: when ti,refp-refn-resistor-ohms is implemented, a
+ * channel using an external resistor reference is effectively
+ * a resistance measurement and should use IIO_RESISTANCE.
+ */
+ spec->type = IIO_VOLTAGE;
+ spec->indexed = 1;
+ spec->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE);
+
+ if (fwnode_property_present(child, "single-channel")) {
+ ret = fwnode_property_read_u32(child, "single-channel", &channel);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "failed to read single-channel property\n");
+
+ if (channel > 3)
+ return dev_err_probe(dev, -EINVAL,
+ "single-channel must be 0-3\n");
+
+ spec->channel = channel;
+ spec->address = ADS112C04_CONF0_MUX_AIN_SINGLE_BASE + channel;
+ } else if (fwnode_property_present(child, "diff-channels")) {
+ ret = fwnode_property_read_u32_array(child, "diff-channels",
+ pair, ARRAY_SIZE(pair));
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "failed to read diff-channels property\n");
+
+ if (pair[0] > 3 || pair[1] > 3)
+ return dev_err_probe(dev, -EINVAL,
+ "diff-channels must be 0-3\n");
+
+ spec->channel = pair[0];
+ spec->channel2 = pair[1];
+ spec->differential = 1;
+
+ if (ads112c04_diff_mux[pair[0]][pair[1]] < 0)
+ return dev_err_probe(dev, -EINVAL,
+ "invalid diff-channels combination\n");
+
+ spec->address = ads112c04_diff_mux[pair[0]][pair[1]];
+ } else {
+ return dev_err_probe(dev, -EINVAL,
+ "channel node must have single-channel or diff-channels\n");
+ }
+
+ i++;
+ }
+
+ indio_dev->channels = channels;
+ indio_dev->num_channels = i;
+
+ return 0;
+}
+
+static int ads112c04_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct iio_dev *indio_dev;
+ struct ads112c04_state *st;
+ struct reset_control *reset;
+ bool need_avdd_ref = false, need_ext_ref = false;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ st->client = client;
+
+ ret = devm_mutex_init(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;
+
+ /* Forward compatibility checks for unimplemented DT properties */
+ if (device_property_present(dev, "refn-supply") ||
+ device_property_present(dev, "ti,refp-refn-resistor-ohms"))
+ return dev_err_probe(dev, -EOPNOTSUPP,
+ "refn-supply and external resistors are not supported yet\n");
+
+ ret = ads112c04_parse_channels(indio_dev, &need_avdd_ref, &need_ext_ref);
+ if (ret)
+ return ret;
+
+ if (need_avdd_ref) {
+ ret = devm_regulator_get_enable_read_voltage(dev, "avdd");
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "failed to get avdd voltage\n");
+
+ st->avdd_mV = ret / (MICRO / MILLI);
+ } else {
+ ret = devm_regulator_get_enable(dev, "avdd");
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to get avdd regulator\n");
+ }
+
+ ret = devm_regulator_get_enable(dev, "dvdd");
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to get dvdd regulator\n");
+
+ if (device_property_present(dev, "refp-supply")) {
+ ret = devm_regulator_get_enable_read_voltage(dev, "refp");
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "failed to get refp voltage\n");
+
+ st->ext_ref_mV = ret / (MICRO / MILLI);
+ }
+
+ if (need_ext_ref && !st->ext_ref_mV)
+ return dev_err_probe(dev, -EINVAL,
+ "external reference measurements require refp-supply\n");
+
+ /* Datasheet: POR releases ~500us after supplies are stable */
+ fsleep(500);
+
+ reset = devm_reset_control_get_optional_exclusive(dev, NULL);
+ if (IS_ERR(reset))
+ return dev_err_probe(dev, PTR_ERR(reset), "failed to get reset\n");
+
+ if (reset) {
+ ret = reset_control_reset(reset);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to reset device\n");
+ } else {
+ ret = ads112c04_write_cmd(client, ADS112C04_CMD_RESET);
+ if (ret < 0)
+ return ret;
+ }
+
+ fsleep(1 * USEC_PER_MSEC);
+
+ /*
+ * Initialize CONFIG0 with all fields explicit: gain of 1 with the PGA
+ * bypassed, which allows full-scale single-ended measurements. The MUX
+ * field is updated per channel before each conversion.
+ */
+ st->config0 = FIELD_PREP(ADS112C04_CONF0_MUX,
+ ADS112C04_CONF0_MUX_AIN0_AIN1) |
+ FIELD_PREP(ADS112C04_CONF0_GAIN,
+ ADS112C04_CONF0_GAIN_X1) |
+ ADS112C04_CONF0_PGA_BYPASS;
+
+ ret = ads112c04_write_reg(client, ADS112C04_REG_CONFIG0, st->config0);
+ if (ret)
+ return ret;
+
+ st->config1 = FIELD_PREP(ADS112C04_CONF1_DR,
+ ADS112C04_CONF1_DR_20SPS) |
+ FIELD_PREP(ADS112C04_CONF1_MODE,
+ ADS112C04_CONF1_MODE_NORMAL) |
+ FIELD_PREP(ADS112C04_CONF1_CM,
+ ADS112C04_CONF1_CM_SINGLE_SHOT) |
+ FIELD_PREP(ADS112C04_CONF1_VREF,
+ ADS112C04_CONF1_VREF_INTERNAL) |
+ FIELD_PREP(ADS112C04_CONF1_TS,
+ ADS112C04_CONF1_TS_DISABLED);
+
+ ret = ads112c04_write_reg(client, ADS112C04_REG_CONFIG1, st->config1);
+ if (ret)
+ return ret;
+
+ if (client->irq > 0) {
+ ret = devm_request_irq(dev, client->irq, ads112c04_irq_handler, 0,
+ indio_dev->name, indio_dev);
+ if (ret)
+ return ret;
+ }
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static const struct i2c_device_id ads112c04_id[] = {
+ { .name = "ads112c04" },
+ { }
+};
+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] 6+ messages in thread
* Re: [PATCH v5 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04
2026-08-13 3:06 ` [PATCH v5 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04 Kyle Hsieh
@ 2026-08-13 3:10 ` sashiko-bot
2026-08-13 16:57 ` Rob Herring
1 sibling, 0 replies; 6+ messages in thread
From: sashiko-bot @ 2026-08-13 3:10 UTC (permalink / raw)
To: Kyle Hsieh; +Cc: robh, conor+dt, devicetree
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The `excitation-current-nanoamp` property incorrectly uses a YAML list for `items`, defining a 1-element tuple constraint instead of a generic array schema, which breaks configurations using dual excitation currents.
--
--- Patch [1]: [PATCH v5 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04 ---
commit 1aa9d5f5c579fdf57e652aeb671cbcbcce2eaa69
Author: Kyle Hsieh <kylehsieh1995@gmail.com>
dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04
This commit adds device tree binding documentation for the Texas Instruments
ADS112C04 I2C Analog-to-Digital Converter. It includes properties for
describing the chip's channels, excitation currents, and reference sources.
> diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
> new file mode 100644
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
[ ... ]
> +patternProperties:
> + "^channel@[0-9a-b]$":
> + $ref: adc.yaml
> + unevaluatedProperties: false
> + properties:
[ ... ]
> + excitation-channels:
> + maxItems: 2
> + items:
> + maximum: 5
> + description:
> + Additionally to AIN0-AIN3, IDAC1/IDAC2 can also be routed to
> + REFP0 (4) and REFN0 (5).
> +
> + excitation-current-nanoamp:
> + items:
> + - enum: [10000, 50000, 100000, 250000, 500000, 1000000, 1500000]
[Severity: Medium]
Will this correctly allow multiple excitation currents? The hyphen before enum
defines a 1-item tuple constraint instead of a generic schema constraint for
all array elements.
If a device tree configuration specifies two excitation channels and provides
two corresponding excitation currents, won't this schema enforce a maximum of
1 item and erroneously reject the valid configuration during dtbs_check?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260813-ti-ads112c04-driver-v5-0-79dff9e249cd@gmail.com?part=1
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v5 2/2] iio: adc: ti-ads112c04: Add support for TI ADS112C04
2026-08-13 3:06 ` [PATCH v5 2/2] iio: adc: ti-ads112c04: Add support for TI ADS112C04 Kyle Hsieh
@ 2026-08-13 3:14 ` sashiko-bot
0 siblings, 0 replies; 6+ messages in thread
From: sashiko-bot @ 2026-08-13 3:14 UTC (permalink / raw)
To: Kyle Hsieh; +Cc: conor+dt, devicetree, robh
Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [High] Interrupt storm on level-triggered lines and probe failure on nested IRQs due to hardirq request.
- [High] Time-of-Check to Time-of-Use (TOCTOU) heap buffer overflow when parsing device tree channels.
- [Medium] Hardware state desynchronization causing silent data corruption after system suspend.
--
--- Patch [2]: [PATCH v5 2/2] iio: adc: ti-ads112c04: Add support for TI ADS112C04 ---
commit 60ab1f79461d9cde81c399c16a9e8fc0068a1dee
Author: Kyle Hsieh <kylehsieh1995@gmail.com>
iio: adc: ti-ads112c04: Add support for TI ADS112C04
Add IIO driver support for the Texas Instruments ADS112C04 (16-bit)
delta-sigma ADCs.
> diff --git a/drivers/iio/adc/ti-ads112c04.c b/drivers/iio/adc/ti-ads112c04.c
> index 0000000000000..c2995e94c4f8d
> --- /dev/null
> +++ b/drivers/iio/adc/ti-ads112c04.c
> @@ -166,15 +166,15 @@ static int ads112c04_get_adc_result(struct iio_dev *indio_dev,
> + unsigned int idx = chan - indio_dev->channels;
> + u8 new_config0, new_config1;
> + int ret;
> +
> + new_config0 = st->config0;
> + FIELD_MODIFY(ADS112C04_CONF0_MUX, &new_config0, chan->address);
> +
> + 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;
> + }
[Severity: Medium]
Could this caching logic lead to silent data corruption after a system
suspend?
The driver skips writing the configuration if it matches the cached
value. Since there are no PM suspend/resume hooks, if the system
enters suspend and power to the ADC is cut, the hardware resets to its
Power-On Reset (POR) state.
Upon resume, if a conversion is requested that matches the cached
configuration, the driver will skip the I2C write. The hardware will
remain in its POR state and return incorrect measurements.
[ ... ]
> @@ -203,9 +203,9 @@ static irqreturn_t ads112c04_irq_handler(int irq, void *private)
> +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;
> +}
[ ... ]
> @@ -223,31 +223,31 @@ static int ads112c04_parse_channels(struct iio_dev *indio_dev,
> +static int ads112c04_parse_channels(struct iio_dev *indio_dev,
> + bool *need_avdd_ref, bool *need_ext_ref)
> +{
> + struct device *dev = indio_dev->dev.parent;
> + struct ads112c04_state *st = iio_priv(indio_dev);
> + struct iio_chan_spec *channels;
> + u32 num_channels, pair[2], channel;
> + unsigned int i;
> + int ret;
> +
> + num_channels = device_get_named_child_node_count(dev, "channel");
> + if (!num_channels)
> + return dev_err_probe(dev, -EINVAL, "no channel subnodes found\n");
> +
> + if (num_channels > ADS112C04_MAX_CHANNELS)
> + return dev_err_probe(dev, -EINVAL,
> + "num of channel nodes exceeds %d\n",
> + ADS112C04_MAX_CHANNELS);
> +
> + channels = devm_kcalloc(dev, num_channels, sizeof(*channels), GFP_KERNEL);
> + if (!channels)
> + return -ENOMEM;
> +
> + st->vref_source = devm_kcalloc(dev, num_channels,
> + sizeof(*st->vref_source), GFP_KERNEL);
> + if (!st->vref_source)
> + return -ENOMEM;
> +
> + i = 0;
> + device_for_each_named_child_node_scoped(dev, child, "channel") {
> + struct iio_chan_spec *spec = &channels[i];
[Severity: High]
Can this cause an out-of-bounds heap write?
The driver counts the number of child nodes to allocate the arrays, and
then iterates over the child nodes to populate them in two separate
traversals.
If a device tree overlay is applied concurrently between the count and
the iteration, the number of child nodes can increase, causing the loop
index 'i' to exceed num_channels.
[ ... ]
> @@ -493,5 +493,5 @@ static int ads112c04_probe(struct i2c_client *client)
> + if (client->irq > 0) {
> + ret = devm_request_irq(dev, client->irq, ads112c04_irq_handler, 0,
> + indio_dev->name, indio_dev);
[Severity: High]
Will this cause an interrupt storm if the DRDY interrupt is configured
as level-triggered?
Since this is requested as a hard IRQ via devm_request_irq(), the
handler completes the completion and returns IRQ_HANDLED without
clearing the hardware interrupt. The line will remain asserted.
Also, if the ADC is connected to a slow bus (like an I2C GPIO
expander) which provides a nested threaded IRQ, will this fail with
-EINVAL?
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260813-ti-ads112c04-driver-v5-0-79dff9e249cd@gmail.com?part=2
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v5 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04
2026-08-13 3:06 ` [PATCH v5 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04 Kyle Hsieh
2026-08-13 3:10 ` sashiko-bot
@ 2026-08-13 16:57 ` Rob Herring
1 sibling, 0 replies; 6+ messages in thread
From: Rob Herring @ 2026-08-13 16:57 UTC (permalink / raw)
To: Kyle Hsieh
Cc: Jonathan Cameron, David Lechner, Nuno Sá, Andy Shevchenko,
Krzysztof Kozlowski, Conor Dooley, Liam Girdwood, Mark Brown,
linux-iio, devicetree, linux-kernel, Conor Dooley
On Thu, Aug 13, 2026 at 11:06:02AM +0800, Kyle Hsieh wrote:
> 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.
>
> Excitation current, burn-out current, and reference source properties
> are also included to fully describe the chip's hardware capabilities,
> aligned with the ti,ads112c14 binding conventions.
>
> Reviewed-by: David Lechner <dlechner@baylibre.com>
> Acked-by: Conor Dooley <conor.dooley@microchip.com>
> Signed-off-by: Kyle Hsieh <kylehsieh1995@gmail.com>
> ---
> .../devicetree/bindings/iio/adc/ti,ads112c04.yaml | 148 +++++++++++++++++++++
> MAINTAINERS | 6 +
> 2 files changed, 154 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..68a0df21cedd
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
> @@ -0,0 +1,148 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/ti,ads112c04.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Texas Instruments ADS112C04 ADC
> +
> +maintainers:
> + - Kyle Hsieh <kylehsieh1995@gmail.com>
> +
> +description:
> + The ADS112C04 (16-bit) are precision analog-to-digital converters (ADCs)
> + with an I2C interface. They feature a flexible input multiplexer, a
> + low-noise programmable gain amplifier (PGA), two programmable excitation
> + current sources, a voltage reference, and a precision temperature sensor.
> +
> +properties:
> + compatible:
> + enum:
> + - ti,ads112c04
> +
> + reg:
> + maxItems: 1
> + description: I2C address of the device.
> +
> + interrupts:
> + maxItems: 1
> + description: Data ready (DRDY) interrupt output.
> +
> + "#address-cells":
> + const: 1
> +
> + "#size-cells":
> + const: 0
> +
> + reset-gpios:
> + maxItems: 1
> + description: GPIO connected to the RESET pin. Active low.
> +
> + avdd-supply: true
> + dvdd-supply: true
> +
> + refp-supply: true
> + refn-supply: true
> +
> + ti,refp-refn-resistor-ohms:
> + description: Resistance of the external resistor between REFP and REFN.
> +
> +patternProperties:
> + "^channel@[0-9a-b]$":
> + $ref: adc.yaml
> + unevaluatedProperties: false
> + properties:
> + reg:
> + items:
> + - maximum: 11
> +
> + single-channel:
> + maximum: 3
> +
> + diff-channels:
> + items:
> + maximum: 3
> +
> + excitation-channels:
> + maxItems: 2
> + items:
> + maximum: 5
> + description:
> + Additionally to AIN0-AIN3, IDAC1/IDAC2 can also be routed to
> + REFP0 (4) and REFN0 (5).
> +
> + excitation-current-nanoamp:
> + items:
> + - enum: [10000, 50000, 100000, 250000, 500000, 1000000, 1500000]
Drop 'items'. Just enum is enough.
> +
> + burn-out-current-nanoamp:
> + items:
> + - const: 10000
Just 'const'
> +
> + reference-sources:
> + items:
> + - enum: [internal, external, avdd]
> + default: internal
default for an items entry doesn't make sense as the entry has to be
present. Instead (at the same level as 'items'):
default: [ internal ]
> +
> + dependencies:
> + excitation-channels: [ excitation-current-nanoamp ]
> + excitation-current-nanoamp: [ excitation-channels ]
> +
> + oneOf:
> + - required: [ single-channel ]
> + - required: [ diff-channels ]
> +
> +required:
> + - compatible
> + - reg
> + - avdd-supply
> + - dvdd-supply
> +
> +dependencies:
> + refn-supply: [ refp-supply ]
> +
> +oneOf:
> + - required:
> + - refp-supply
Just to make sure, refp-supply is allowed without refn-supply? If not,
either this should be refn or the dependencies reversed.
Rob
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-08-13 16:57 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-13 3:06 [PATCH v5 0/2] iio: adc: Add support for Texas Instruments ADS112C04 Kyle Hsieh
2026-08-13 3:06 ` [PATCH v5 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04 Kyle Hsieh
2026-08-13 3:10 ` sashiko-bot
2026-08-13 16:57 ` Rob Herring
2026-08-13 3:06 ` [PATCH v5 2/2] iio: adc: ti-ads112c04: Add support for TI ADS112C04 Kyle Hsieh
2026-08-13 3:14 ` sashiko-bot
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