* [PATCH v3 1/5] dt-bindings: iio: adc: Add ltc2378
2026-06-17 2:02 [PATCH v3 0/5] iio: adc: Add support for LTC2378 and similar ADCs Marcelo Schmitt
@ 2026-06-17 2:03 ` Marcelo Schmitt
2026-06-17 2:03 ` [PATCH v3 2/5] iio: adc: ltc2378: Add support for LTC2378-20 and similar ADCs Marcelo Schmitt
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Marcelo Schmitt @ 2026-06-17 2:03 UTC (permalink / raw)
To: linux-iio, devicetree, linux-kernel
Cc: jic23, nuno.sa, Michael.Hennerich, dlechner, andy, robh, krzk+dt,
conor+dt, pop.ioan-daniel, marcelo.schmitt1
Document how to describe LTC2378-20 and similar ADCs in device tree.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v2 -> v3:
- Re-added device tree fallback compatibles for LTC2378 chips, now with options
to provide a single compatible string or a pair of single compatible string
plus a fallback string to a slower sample rate spec in case a driver for the
specific part is not found.
.../bindings/iio/adc/adi,ltc2378.yaml | 160 ++++++++++++++++++
MAINTAINERS | 7 +
2 files changed, 167 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ltc2378.yaml
diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ltc2378.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ltc2378.yaml
new file mode 100644
index 000000000000..7d30a2cade8f
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ltc2378.yaml
@@ -0,0 +1,160 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ltc2378.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices LTC2378 and similar Analog to Digital Converters
+
+maintainers:
+ - Marcelo Schmitt <marcelo.schmitt@analog.com>
+
+description: |
+ Analog Devices LTC2378 series of ADCs.
+ Specifications can be found at:
+ https://www.analog.com/media/en/technical-documentation/data-sheets/233818fa.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/236416fa.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/236418f.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/236716fa.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/236718f.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/236816f.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/236818f.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/236918fa.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/237016fa.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/237616fa.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/237618fa.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/237620fb.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/237716fa.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/237718fa.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/237720fb.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/237816fa.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/237818fa.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/237820fb.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/237918fb.pdf
+ https://www.analog.com/media/en/technical-documentation/data-sheets/238016fb.pdf
+
+$ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+ compatible:
+ oneOf:
+ # Single compatible string match.
+ - enum:
+ - adi,ltc2338-18
+ - adi,ltc2364-16
+ - adi,ltc2364-18
+ - adi,ltc2367-16
+ - adi,ltc2367-18
+ - adi,ltc2368-16
+ - adi,ltc2368-18
+ - adi,ltc2369-18
+ - adi,ltc2370-16
+ - adi,ltc2376-16
+ - adi,ltc2376-18
+ - adi,ltc2376-20
+ - adi,ltc2377-16
+ - adi,ltc2377-18
+ - adi,ltc2377-20
+ - adi,ltc2378-16
+ - adi,ltc2378-18
+ - adi,ltc2378-20
+ - adi,ltc2379-18
+ - adi,ltc2380-16
+
+ # Low sample rate fallback for 16-bit unipolar sensors.
+ - items:
+ - enum:
+ - adi,ltc2370-16 # 2 MSPS
+ - adi,ltc2368-16 # 1 MSPS
+ - adi,ltc2367-16 # 500 kSPS
+ - const: adi,ltc2364-16 # fallback (250 kSPS)
+
+ # Low sample rate fallback for 18-bit unipolar sensors.
+ - items:
+ - enum:
+ - adi,ltc2369-18 # 1.6 MSPS
+ - adi,ltc2368-18 # 1 MSPS
+ - adi,ltc2367-18 # 500 kSPS
+ - const: adi,ltc2364-18 # fallback (250 kSPS)
+
+ # Low sample rate fallback for 16-bit bipolar sensors.
+ - items:
+ - enum:
+ - adi,ltc2380-16 # 2 MSPS
+ - adi,ltc2378-16 # 1 MSPS
+ - adi,ltc2377-16 # 500 kSPS
+ - const: adi,ltc2376-16 # fallback (250 kSPS)
+
+ # Low sample rate fallback for 18-bit bipolar sensors.
+ - items:
+ - enum:
+ - adi,ltc2379-18 # 1.6 MSPS
+ - adi,ltc2338-18 # 1 MSPS
+ - adi,ltc2378-18 # 1 MSPS
+ - adi,ltc2377-18 # 500 kSPS
+ - const: adi,ltc2376-18 # fallback (250 kSPS)
+
+ # Low sample rate fallback for 20-bit bipolar sensors.
+ - items:
+ - enum:
+ - adi,ltc2378-20 # 1 MSPS
+ - adi,ltc2377-20 # 500 kSPS
+ - const: adi,ltc2376-20 # fallback (250 kSPS)
+
+ reg:
+ maxItems: 1
+
+ spi-max-frequency:
+ maximum: 100000000
+
+ vdd-supply:
+ description: A 2.5V supply that powers the chip (VDD).
+
+ ovdd-supply:
+ description:
+ A 1.71V to 5.25V supply that sets the logic level for digital interface.
+
+ ref-supply:
+ description:
+ A 2.5V to 5.1V supply for the reference input (REF).
+
+ cnv-gpios:
+ description:
+ When provided, this property indicates the GPIO that is connected to the
+ CNV pin.
+ maxItems: 1
+
+ interrupts:
+ description:
+ Interrupt for signaling the completion of conversion results. The active
+ low signal provided on the BUSY pin asserts when ADC conversions finish.
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - vdd-supply
+ - ovdd-supply
+ - ref-supply
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ #include <dt-bindings/interrupt-controller/irq.h>
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ adc@0 {
+ compatible = "adi,ltc2378-20", "adi,ltc2376-20";
+ reg = <0>;
+ spi-max-frequency = <71000000>;
+ vdd-supply = <&supply_2_5V>;
+ ovdd-supply = <&supply_3_3V>;
+ ref-supply = <&supply_5V>;
+ cnv-gpios = <&gpio0 88 GPIO_ACTIVE_HIGH>;
+ interrupts = <7 IRQ_TYPE_EDGE_FALLING>;
+ interrupt-parent = <&gpio>;
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index b051eccafa60..205acb4b0789 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15220,6 +15220,13 @@ S: Maintained
F: Documentation/devicetree/bindings/iio/dac/lltc,ltc1660.yaml
F: drivers/iio/dac/ltc1660.c
+LTC2378 IIO ADC DRIVER
+M: Marcelo Schmitt <marcelo.schmitt@analog.com>
+L: linux-iio@vger.kernel.org
+S: Supported
+W: https://ez.analog.com/linux-software-drivers
+F: Documentation/devicetree/bindings/iio/adc/adi,ltc2378.yaml
+
LTC2664 IIO DAC DRIVER
M: Michael Hennerich <michael.hennerich@analog.com>
M: Kim Seer Paller <kimseer.paller@analog.com>
--
2.53.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 2/5] iio: adc: ltc2378: Add support for LTC2378-20 and similar ADCs
2026-06-17 2:02 [PATCH v3 0/5] iio: adc: Add support for LTC2378 and similar ADCs Marcelo Schmitt
2026-06-17 2:03 ` [PATCH v3 1/5] dt-bindings: iio: adc: Add ltc2378 Marcelo Schmitt
@ 2026-06-17 2:03 ` Marcelo Schmitt
2026-06-17 2:03 ` [RFC PATCH v3 3/5] iio: buffer: Extend DMAengine buffer interfaces to take extra sysfs attributes Marcelo Schmitt
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Marcelo Schmitt @ 2026-06-17 2:03 UTC (permalink / raw)
To: linux-iio, devicetree, linux-kernel
Cc: jic23, nuno.sa, Michael.Hennerich, dlechner, andy, robh, krzk+dt,
conor+dt, pop.ioan-daniel, marcelo.schmitt1
Support for LTC2378-20 and similar analog-to-digital converters.
Co-developed-by: Ioan-Daniel Pop <pop.ioan-daniel@analog.com>
Signed-off-by: Ioan-Daniel Pop <pop.ioan-daniel@analog.com>
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v2 -> v3:
- Restricted LTC2378 dependency list to require GPIO
- Use datasheet terminology to indicate polarity/output code.
- Added missing block scope to IIO_DEV_ACQUIRE_DIRECT_MODE.
MAINTAINERS | 1 +
drivers/iio/adc/Kconfig | 11 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ltc2378.c | 338 ++++++++++++++++++++++++++++++++++++++
drivers/iio/adc/ltc2378.h | 63 +++++++
5 files changed, 414 insertions(+)
create mode 100644 drivers/iio/adc/ltc2378.c
create mode 100644 drivers/iio/adc/ltc2378.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 205acb4b0789..a11c00a78c13 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15226,6 +15226,7 @@ L: linux-iio@vger.kernel.org
S: Supported
W: https://ez.analog.com/linux-software-drivers
F: Documentation/devicetree/bindings/iio/adc/adi,ltc2378.yaml
+F: drivers/iio/adc/ltc2378*
LTC2664 IIO DAC DRIVER
M: Michael Hennerich <michael.hennerich@analog.com>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index a3a93a47b43d..2b8203451367 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -940,6 +940,17 @@ config LTC2309
This driver can also be built as a module. If so, the module will
be called ltc2309.
+config LTC2378
+ tristate "Analog Devices LTC2378 ADC driver"
+ depends on SPI
+ depends on GPIOLIB
+ help
+ Say yes here to build support for Analog Devices LTC2378-20 and
+ similar analog to digital converters.
+
+ This driver can also be built as a module. If so, the module will
+ be called ltc2378.
+
config LTC2471
tristate "Linear Technology LTC2471 and LTC2473 ADC driver"
depends on I2C
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 707dd708912f..1814fb78dde3 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
obj-$(CONFIG_LTC2309) += ltc2309.o
+obj-$(CONFIG_LTC2378) += ltc2378.o
obj-$(CONFIG_LTC2471) += ltc2471.o
obj-$(CONFIG_LTC2485) += ltc2485.o
obj-$(CONFIG_LTC2496) += ltc2496.o ltc2497-core.o
diff --git a/drivers/iio/adc/ltc2378.c b/drivers/iio/adc/ltc2378.c
new file mode 100644
index 000000000000..88582bdcd6a6
--- /dev/null
+++ b/drivers/iio/adc/ltc2378.c
@@ -0,0 +1,338 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Analog Devices LTC2378 ADC series driver
+ *
+ * Copyright (C) 2026 Analog Devices Inc.
+ * Author: Ioan-Daniel Pop <pop.ioan-daniel@analog.com>
+ * Author: Marcelo Schmitt <marcelo.schmitt@analog.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/types.h>
+
+#include "ltc2378.h"
+
+static const struct ltc2378_chip_info ltc2338_18_chip_info = {
+ .name = "ltc2338-18",
+ .resolution = 18,
+ .bipolar = true,
+};
+
+static const struct ltc2378_chip_info ltc2364_16_chip_info = {
+ .name = "ltc2364-16",
+ .resolution = 16,
+ .bipolar = false,
+};
+
+static const struct ltc2378_chip_info ltc2364_18_chip_info = {
+ .name = "ltc2364-18",
+ .resolution = 18,
+ .bipolar = false,
+};
+
+static const struct ltc2378_chip_info ltc2367_16_chip_info = {
+ .name = "ltc2367-16",
+ .resolution = 16,
+ .bipolar = false,
+};
+
+static const struct ltc2378_chip_info ltc2367_18_chip_info = {
+ .name = "ltc2367-18",
+ .resolution = 18,
+ .bipolar = false,
+};
+
+static const struct ltc2378_chip_info ltc2368_16_chip_info = {
+ .name = "ltc2368-16",
+ .resolution = 16,
+ .bipolar = false,
+};
+
+static const struct ltc2378_chip_info ltc2368_18_chip_info = {
+ .name = "ltc2368-18",
+ .resolution = 18,
+ .bipolar = false,
+};
+
+static const struct ltc2378_chip_info ltc2369_18_chip_info = {
+ .name = "ltc2369-18",
+ .resolution = 18,
+ .bipolar = false,
+};
+
+static const struct ltc2378_chip_info ltc2370_16_chip_info = {
+ .name = "ltc2370-16",
+ .resolution = 16,
+ .bipolar = false,
+};
+
+static const struct ltc2378_chip_info ltc2376_16_chip_info = {
+ .name = "ltc2376-16",
+ .resolution = 16,
+ .bipolar = true,
+};
+
+static const struct ltc2378_chip_info ltc2376_18_chip_info = {
+ .name = "ltc2376-18",
+ .resolution = 18,
+ .bipolar = true,
+};
+
+static const struct ltc2378_chip_info ltc2376_20_chip_info = {
+ .name = "ltc2376-20",
+ .resolution = 20,
+ .bipolar = true,
+};
+
+static const struct ltc2378_chip_info ltc2377_16_chip_info = {
+ .name = "ltc2377-16",
+ .resolution = 16,
+ .bipolar = true,
+};
+
+static const struct ltc2378_chip_info ltc2377_18_chip_info = {
+ .name = "ltc2377-18",
+ .resolution = 18,
+ .bipolar = true,
+};
+
+static const struct ltc2378_chip_info ltc2377_20_chip_info = {
+ .name = "ltc2377-20",
+ .resolution = 20,
+ .bipolar = true,
+};
+
+static const struct ltc2378_chip_info ltc2378_16_chip_info = {
+ .name = "ltc2378-16",
+ .resolution = 16,
+ .bipolar = true,
+};
+
+static const struct ltc2378_chip_info ltc2378_18_chip_info = {
+ .name = "ltc2378-18",
+ .resolution = 18,
+ .bipolar = true,
+};
+
+static const struct ltc2378_chip_info ltc2378_20_chip_info = {
+ .name = "ltc2378-20",
+ .resolution = 20,
+ .bipolar = true,
+};
+
+static const struct ltc2378_chip_info ltc2379_18_chip_info = {
+ .name = "ltc2379-18",
+ .resolution = 18,
+ .bipolar = true,
+};
+
+static const struct ltc2378_chip_info ltc2380_16_chip_info = {
+ .name = "ltc2380-16",
+ .resolution = 16,
+ .bipolar = true,
+};
+
+static int ltc2378_channel_single_read(const struct iio_chan_spec *chan,
+ struct ltc2378_state *st, int *val)
+{
+ const struct iio_scan_type *scan_type = &chan->scan_type;
+ u32 sample;
+ int ret;
+
+ ret = ltc2378_convert_and_acquire(st);
+ if (ret)
+ return ret;
+
+ if (scan_type->realbits > 16)
+ sample = st->scan.data.sample_buf32;
+ else
+ sample = st->scan.data.sample_buf16;
+
+ if (scan_type->format == IIO_SCAN_FORMAT_SIGNED_INT)
+ *val = sign_extend32(sample, scan_type->realbits - 1);
+ else
+ *val = sample;
+
+ return 0;
+}
+
+static int ltc2378_read_raw(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ int *val, int *val2, long info)
+{
+ struct ltc2378_state *st = iio_priv(indio_dev);
+ int ret;
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW: {
+ IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim);
+ if (IIO_DEV_ACQUIRE_FAILED(claim))
+ return -EBUSY;
+
+ ret = ltc2378_channel_single_read(chan, st, val);
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ *val = st->ref_uV / MILLI;
+ /*
+ * For all LTC2378-like devices, the amount of bits that express
+ * voltage magnitude depend on the polarity / output code format:
+ * - straight binary: All precision/resolution bits are used.
+ * - 2's complement: One of the precision bits is used for sign.
+ */
+ if (st->info->bipolar)
+ *val2 = st->info->resolution - 1;
+ else
+ *val2 = st->info->resolution;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info ltc2378_iio_info = {
+ .read_raw = <c2378_read_raw,
+};
+
+static int ltc2378_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct iio_dev *indio_dev;
+ struct ltc2378_state *st;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ st->spi = spi;
+
+ ret = devm_regulator_get_enable_read_voltage(dev, "ref");
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "failed to read ref regulator\n");
+
+ st->ref_uV = ret;
+ st->info = spi_get_device_match_data(spi);
+ if (!st->info)
+ return -EINVAL;
+
+ indio_dev->name = st->info->name;
+ indio_dev->info = <c2378_iio_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ st->cnv_gpio = devm_gpiod_get(dev, "cnv", GPIOD_OUT_LOW);
+ if (IS_ERR(st->cnv_gpio))
+ return dev_err_probe(dev, PTR_ERR(st->cnv_gpio),
+ "failed to get CNV GPIO");
+
+ st->num_iio_chans = 0;
+ st->chans[st->num_iio_chans++] = (struct iio_chan_spec) {
+ .type = IIO_VOLTAGE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .scan_index = 0,
+ .scan_type = {
+ .format = st->info->bipolar ? IIO_SCAN_FORMAT_SIGNED_INT :
+ IIO_SCAN_FORMAT_UNSIGNED_INT,
+ .realbits = st->info->resolution,
+ /*
+ * Buffer elements could be 16-bit for low precision
+ * parts. Though, using more storage bits allows keeping
+ * the same scan_type configuration for both types of
+ * buffer support.
+ */
+ .storagebits = 32,
+ },
+ };
+
+ st->xfer.rx_buf = &st->scan.data;
+ st->xfer.len = st->info->resolution > 16 ? 4 : 2;
+ st->xfer.bits_per_word = st->info->resolution;
+
+ indio_dev->channels = st->chans;
+ indio_dev->num_channels = st->num_iio_chans;
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct of_device_id ltc2378_of_match[] = {
+ { .compatible = "adi,ltc2338-18", .data = <c2338_18_chip_info },
+ { .compatible = "adi,ltc2364-16", .data = <c2364_16_chip_info },
+ { .compatible = "adi,ltc2364-18", .data = <c2364_18_chip_info },
+ { .compatible = "adi,ltc2367-16", .data = <c2367_16_chip_info },
+ { .compatible = "adi,ltc2367-18", .data = <c2367_18_chip_info },
+ { .compatible = "adi,ltc2368-16", .data = <c2368_16_chip_info },
+ { .compatible = "adi,ltc2368-18", .data = <c2368_18_chip_info },
+ { .compatible = "adi,ltc2369-18", .data = <c2369_18_chip_info },
+ { .compatible = "adi,ltc2370-16", .data = <c2370_16_chip_info },
+ { .compatible = "adi,ltc2376-16", .data = <c2376_16_chip_info },
+ { .compatible = "adi,ltc2376-18", .data = <c2376_18_chip_info },
+ { .compatible = "adi,ltc2376-20", .data = <c2376_20_chip_info },
+ { .compatible = "adi,ltc2377-16", .data = <c2377_16_chip_info },
+ { .compatible = "adi,ltc2377-18", .data = <c2377_18_chip_info },
+ { .compatible = "adi,ltc2377-20", .data = <c2377_20_chip_info },
+ { .compatible = "adi,ltc2378-16", .data = <c2378_16_chip_info },
+ { .compatible = "adi,ltc2378-18", .data = <c2378_18_chip_info },
+ { .compatible = "adi,ltc2378-20", .data = <c2378_20_chip_info },
+ { .compatible = "adi,ltc2379-18", .data = <c2379_18_chip_info },
+ { .compatible = "adi,ltc2380-16", .data = <c2380_16_chip_info },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ltc2378_of_match);
+
+static const struct spi_device_id ltc2378_spi_id[] = {
+ { .name = "ltc2338-18", .driver_data = (kernel_ulong_t)<c2338_18_chip_info },
+ { .name = "ltc2364-16", .driver_data = (kernel_ulong_t)<c2364_16_chip_info },
+ { .name = "ltc2364-18", .driver_data = (kernel_ulong_t)<c2364_18_chip_info },
+ { .name = "ltc2367-16", .driver_data = (kernel_ulong_t)<c2367_16_chip_info },
+ { .name = "ltc2367-18", .driver_data = (kernel_ulong_t)<c2367_18_chip_info },
+ { .name = "ltc2368-16", .driver_data = (kernel_ulong_t)<c2368_16_chip_info },
+ { .name = "ltc2368-18", .driver_data = (kernel_ulong_t)<c2368_18_chip_info },
+ { .name = "ltc2369-18", .driver_data = (kernel_ulong_t)<c2369_18_chip_info },
+ { .name = "ltc2370-16", .driver_data = (kernel_ulong_t)<c2370_16_chip_info },
+ { .name = "ltc2376-16", .driver_data = (kernel_ulong_t)<c2376_16_chip_info },
+ { .name = "ltc2376-18", .driver_data = (kernel_ulong_t)<c2376_18_chip_info },
+ { .name = "ltc2376-20", .driver_data = (kernel_ulong_t)<c2376_20_chip_info },
+ { .name = "ltc2377-16", .driver_data = (kernel_ulong_t)<c2377_16_chip_info },
+ { .name = "ltc2377-18", .driver_data = (kernel_ulong_t)<c2377_18_chip_info },
+ { .name = "ltc2377-20", .driver_data = (kernel_ulong_t)<c2377_20_chip_info },
+ { .name = "ltc2378-16", .driver_data = (kernel_ulong_t)<c2378_16_chip_info },
+ { .name = "ltc2378-18", .driver_data = (kernel_ulong_t)<c2378_18_chip_info },
+ { .name = "ltc2378-20", .driver_data = (kernel_ulong_t)<c2378_20_chip_info },
+ { .name = "ltc2379-18", .driver_data = (kernel_ulong_t)<c2379_18_chip_info },
+ { .name = "ltc2380-16", .driver_data = (kernel_ulong_t)<c2380_16_chip_info },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, ltc2378_spi_id);
+
+static struct spi_driver ltc2378_driver = {
+ .driver = {
+ .name = "ltc2378",
+ .of_match_table = ltc2378_of_match
+ },
+ .probe = ltc2378_probe,
+ .id_table = ltc2378_spi_id,
+};
+module_spi_driver(ltc2378_driver);
+
+MODULE_AUTHOR("Ioan-Daniel Pop <pop.ioan-daniel@analog.com>");
+MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt@analog.com>");
+MODULE_DESCRIPTION("Analog Devices LTC2378 ADC series driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/adc/ltc2378.h b/drivers/iio/adc/ltc2378.h
new file mode 100644
index 000000000000..a3a69351de6c
--- /dev/null
+++ b/drivers/iio/adc/ltc2378.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Analog Devices LTC2378 and similar ADCs common definitions and properties
+ * Copyright (C) 2026 Analog Devices, Inc.
+ * Author: Marcelo Schmitt <marcelo.schmitt@analog.com>
+ */
+
+#ifndef __DRIVERS_IIO_ADC_LTC2378_H__
+#define __DRIVERS_IIO_ADC_LTC2378_H__
+
+#include <linux/iio/iio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/delay.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+#include <linux/units.h>
+
+#define LTC2378_TDSDOBUSYL_NS 5
+#define LTC2378_TBUSYLH_NS 13
+#define LTC2378_TCNV_HIGH_NS 20
+
+struct ltc2378_chip_info {
+ const char *name;
+ int resolution;
+ bool bipolar;
+};
+
+struct ltc2378_state {
+ const struct ltc2378_chip_info *info;
+ struct gpio_desc *cnv_gpio;
+ struct spi_device *spi;
+ struct spi_transfer xfer;
+ unsigned int num_iio_chans;
+ struct iio_chan_spec chans[2]; /* 1 physical chan + 1 timestamp chan */
+ int ref_uV;
+
+ /*
+ * DMA (thus cache coherency maintenance) requires the
+ * transfer buffers to live in their own cache lines.
+ */
+ struct {
+ union {
+ u16 sample_buf16;
+ u32 sample_buf32;
+ } data;
+ aligned_s64 timestamp;
+ } scan __aligned(IIO_DMA_MINALIGN);
+};
+
+static inline int ltc2378_convert_and_acquire(struct ltc2378_state *st)
+{
+ int ret;
+
+ /* Cause a rising edge of CNV to initiate a new ADC conversion */
+ gpiod_set_value_cansleep(st->cnv_gpio, 1);
+ fsleep(4);
+ ret = spi_sync_transfer(st->spi, &st->xfer, 1);
+ gpiod_set_value_cansleep(st->cnv_gpio, 0);
+
+ return ret;
+}
+
+#endif /* __DRIVERS_IIO_ADC_LTC2378_H__ */
--
2.53.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [RFC PATCH v3 3/5] iio: buffer: Extend DMAengine buffer interfaces to take extra sysfs attributes
2026-06-17 2:02 [PATCH v3 0/5] iio: adc: Add support for LTC2378 and similar ADCs Marcelo Schmitt
2026-06-17 2:03 ` [PATCH v3 1/5] dt-bindings: iio: adc: Add ltc2378 Marcelo Schmitt
2026-06-17 2:03 ` [PATCH v3 2/5] iio: adc: ltc2378: Add support for LTC2378-20 and similar ADCs Marcelo Schmitt
@ 2026-06-17 2:03 ` Marcelo Schmitt
2026-06-17 2:04 ` [PATCH v3 4/5] iio: adc: ltc2378: Enable high-speed data capture Marcelo Schmitt
2026-06-17 2:04 ` [PATCH v3 5/5] iio: adc: ltc2378: Enable triggered buffer " Marcelo Schmitt
4 siblings, 0 replies; 6+ messages in thread
From: Marcelo Schmitt @ 2026-06-17 2:03 UTC (permalink / raw)
To: linux-iio, devicetree, linux-kernel
Cc: jic23, nuno.sa, Michael.Hennerich, dlechner, andy, robh, krzk+dt,
conor+dt, pop.ioan-daniel, marcelo.schmitt1
Some devices using DMAengine buffers are connected to extra hardware that
allows setting how fast data is transferred to/from the buffer. However,
those extra pieces of harwdware are external to the sensor chip such that
supporting the transfer speed as a sensor property is a bit of an
inaccuracy. Expand IIO DMAengine buffer interfaces to take arguments for
extra sysfs attributes, enabling the transfer speed to be configured
through the buffer interface.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
New patch.
Now that I've come to this buffer "solution", I have pretty much convinced
myself it would be better to instead have some sort of IIO trigger to control
the signal source connected to SPI offloading trigger module.
drivers/iio/adc/ad4000.c | 3 ++-
drivers/iio/adc/ad4030.c | 3 ++-
drivers/iio/adc/ad4691.c | 3 ++-
drivers/iio/adc/ad4695.c | 2 +-
drivers/iio/adc/ad7380.c | 2 +-
drivers/iio/adc/ad7606_spi.c | 2 +-
drivers/iio/adc/ad7768-1.c | 3 ++-
drivers/iio/adc/ad7944.c | 2 +-
drivers/iio/adc/ad_sigma_delta.c | 2 +-
.../buffer/industrialio-buffer-dmaengine.c | 19 ++++++++++++-------
drivers/iio/dac/ad5791.c | 2 +-
drivers/iio/dac/ad8460.c | 2 +-
drivers/iio/dac/adi-axi-dac.c | 2 +-
include/linux/iio/buffer-dmaengine.h | 16 ++++++++++------
14 files changed, 38 insertions(+), 25 deletions(-)
diff --git a/drivers/iio/adc/ad4000.c b/drivers/iio/adc/ad4000.c
index fd3d79fca785..b79b627310af 100644
--- a/drivers/iio/adc/ad4000.c
+++ b/drivers/iio/adc/ad4000.c
@@ -871,7 +871,8 @@ static int ad4000_spi_offload_setup(struct iio_dev *indio_dev,
"Failed to get offload RX DMA\n");
ret = devm_iio_dmaengine_buffer_setup_with_handle(dev, indio_dev, rx_dma,
- IIO_BUFFER_DIRECTION_IN);
+ IIO_BUFFER_DIRECTION_IN,
+ NULL);
if (ret)
return dev_err_probe(dev, ret, "Failed to setup DMA buffer\n");
diff --git a/drivers/iio/adc/ad4030.c b/drivers/iio/adc/ad4030.c
index 9c5f19321e3b..713fe95176c0 100644
--- a/drivers/iio/adc/ad4030.c
+++ b/drivers/iio/adc/ad4030.c
@@ -1400,7 +1400,8 @@ static int ad4030_spi_offload_setup(struct iio_dev *indio_dev,
"failed to get offload RX DMA\n");
return devm_iio_dmaengine_buffer_setup_with_handle(dev, indio_dev, rx_dma,
- IIO_BUFFER_DIRECTION_IN);
+ IIO_BUFFER_DIRECTION_IN,
+ NULL);
}
static int ad4030_setup_pga(struct device *dev, struct iio_dev *indio_dev,
diff --git a/drivers/iio/adc/ad4691.c b/drivers/iio/adc/ad4691.c
index 548678adc2a4..9845fe9c4725 100644
--- a/drivers/iio/adc/ad4691.c
+++ b/drivers/iio/adc/ad4691.c
@@ -1980,7 +1980,8 @@ static int ad4691_setup_offload(struct iio_dev *indio_dev,
indio_dev->setup_ops = &ad4691_cnv_burst_offload_buffer_setup_ops;
ret = devm_iio_dmaengine_buffer_setup_with_handle(dev, indio_dev, rx_dma,
- IIO_BUFFER_DIRECTION_IN);
+ IIO_BUFFER_DIRECTION_IN,
+ NULL);
if (ret)
return ret;
diff --git a/drivers/iio/adc/ad4695.c b/drivers/iio/adc/ad4695.c
index 53642de7330d..78faeade19f5 100644
--- a/drivers/iio/adc/ad4695.c
+++ b/drivers/iio/adc/ad4695.c
@@ -1779,7 +1779,7 @@ static int ad4695_probe_spi_offload(struct iio_dev *indio_dev,
}
return devm_iio_dmaengine_buffer_setup_with_handle(dev, indio_dev,
- rx_dma, IIO_BUFFER_DIRECTION_IN);
+ rx_dma, IIO_BUFFER_DIRECTION_IN, NULL);
}
static const struct spi_offload_config ad4695_spi_offload_config = {
diff --git a/drivers/iio/adc/ad7380.c b/drivers/iio/adc/ad7380.c
index 9f77990a03f9..415b8e1be920 100644
--- a/drivers/iio/adc/ad7380.c
+++ b/drivers/iio/adc/ad7380.c
@@ -1874,7 +1874,7 @@ static int ad7380_probe_spi_offload(struct iio_dev *indio_dev,
"failed to get offload RX DMA\n");
ret = devm_iio_dmaengine_buffer_setup_with_handle(dev, indio_dev,
- rx_dma, IIO_BUFFER_DIRECTION_IN);
+ rx_dma, IIO_BUFFER_DIRECTION_IN, NULL);
if (ret)
return dev_err_probe(dev, ret, "cannot setup dma buffer\n");
diff --git a/drivers/iio/adc/ad7606_spi.c b/drivers/iio/adc/ad7606_spi.c
index 7e17ccbcedd0..760b54bfe208 100644
--- a/drivers/iio/adc/ad7606_spi.c
+++ b/drivers/iio/adc/ad7606_spi.c
@@ -317,7 +317,7 @@ static int ad7606_spi_offload_probe(struct device *dev,
"failed to get offload RX DMA\n");
ret = devm_iio_dmaengine_buffer_setup_with_handle(dev, indio_dev,
- rx_dma, IIO_BUFFER_DIRECTION_IN);
+ rx_dma, IIO_BUFFER_DIRECTION_IN, NULL);
if (ret)
return dev_err_probe(dev, ret,
"failed to setup offload RX DMA\n");
diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c
index 598936e47fd2..a13ac31281d8 100644
--- a/drivers/iio/adc/ad7768-1.c
+++ b/drivers/iio/adc/ad7768-1.c
@@ -1792,7 +1792,8 @@ static int ad7768_spi_offload_probe(struct iio_dev *indio_dev,
return dev_err_probe(dev, PTR_ERR(rx_dma), "failed to get offload RX DMA\n");
ret = devm_iio_dmaengine_buffer_setup_with_handle(dev, indio_dev, rx_dma,
- IIO_BUFFER_DIRECTION_IN);
+ IIO_BUFFER_DIRECTION_IN,
+ NULL);
if (ret)
return dev_err_probe(dev, ret, "failed to setup offload RX DMA\n");
diff --git a/drivers/iio/adc/ad7944.c b/drivers/iio/adc/ad7944.c
index 7722cf9e8214..63852a6c2acc 100644
--- a/drivers/iio/adc/ad7944.c
+++ b/drivers/iio/adc/ad7944.c
@@ -843,7 +843,7 @@ static int ad7944_probe(struct spi_device *spi)
*/
ret = devm_iio_dmaengine_buffer_setup_with_handle(dev,
- indio_dev, rx_dma, IIO_BUFFER_DIRECTION_IN);
+ indio_dev, rx_dma, IIO_BUFFER_DIRECTION_IN, NULL);
if (ret)
return ret;
diff --git a/drivers/iio/adc/ad_sigma_delta.c b/drivers/iio/adc/ad_sigma_delta.c
index a955556f9ec8..4b88e1c72c87 100644
--- a/drivers/iio/adc/ad_sigma_delta.c
+++ b/drivers/iio/adc/ad_sigma_delta.c
@@ -820,7 +820,7 @@ int devm_ad_sd_setup_buffer_and_trigger(struct device *dev, struct iio_dev *indi
"Failed to get RX DMA channel\n");
ret = devm_iio_dmaengine_buffer_setup_with_handle(dev, indio_dev,
- rx_dma, IIO_BUFFER_DIRECTION_IN);
+ rx_dma, IIO_BUFFER_DIRECTION_IN, NULL);
if (ret)
return dev_err_probe(dev, ret, "Cannot setup DMA buffer\n");
diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index 98acce909854..343dbb6d1446 100644
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
@@ -289,7 +289,8 @@ EXPORT_SYMBOL_NS_GPL(iio_dmaengine_buffer_teardown, "IIO_DMAENGINE_BUFFER");
static struct iio_buffer
*__iio_dmaengine_buffer_setup_ext(struct iio_dev *indio_dev,
struct dma_chan *chan,
- enum iio_buffer_direction dir)
+ enum iio_buffer_direction dir,
+ const struct iio_dev_attr **buffer_attrs)
{
struct iio_buffer *buffer;
int ret;
@@ -301,6 +302,7 @@ static struct iio_buffer
indio_dev->modes |= INDIO_BUFFER_HARDWARE;
buffer->direction = dir;
+ buffer->attrs = buffer_attrs;
ret = iio_device_attach_buffer(indio_dev, buffer);
if (ret) {
@@ -329,7 +331,8 @@ static struct iio_buffer
struct iio_buffer *iio_dmaengine_buffer_setup_ext(struct device *dev,
struct iio_dev *indio_dev,
const char *channel,
- enum iio_buffer_direction dir)
+ enum iio_buffer_direction dir,
+ const struct iio_dev_attr **buffer_attrs)
{
struct dma_chan *chan;
struct iio_buffer *buffer;
@@ -338,7 +341,7 @@ struct iio_buffer *iio_dmaengine_buffer_setup_ext(struct device *dev,
if (IS_ERR(chan))
return ERR_CAST(chan);
- buffer = __iio_dmaengine_buffer_setup_ext(indio_dev, chan, dir);
+ buffer = __iio_dmaengine_buffer_setup_ext(indio_dev, chan, dir, buffer_attrs);
if (IS_ERR(buffer))
dma_release_channel(chan);
@@ -366,11 +369,12 @@ static void devm_iio_dmaengine_buffer_teardown(void *buffer)
int devm_iio_dmaengine_buffer_setup_ext(struct device *dev,
struct iio_dev *indio_dev,
const char *channel,
- enum iio_buffer_direction dir)
+ enum iio_buffer_direction dir,
+ const struct iio_dev_attr **buffer_attrs)
{
struct iio_buffer *buffer;
- buffer = iio_dmaengine_buffer_setup_ext(dev, indio_dev, channel, dir);
+ buffer = iio_dmaengine_buffer_setup_ext(dev, indio_dev, channel, dir, buffer_attrs);
if (IS_ERR(buffer))
return PTR_ERR(buffer);
@@ -403,11 +407,12 @@ static void devm_iio_dmaengine_buffer_free(void *buffer)
int devm_iio_dmaengine_buffer_setup_with_handle(struct device *dev,
struct iio_dev *indio_dev,
struct dma_chan *chan,
- enum iio_buffer_direction dir)
+ enum iio_buffer_direction dir,
+ const struct iio_dev_attr **buffer_attrs)
{
struct iio_buffer *buffer;
- buffer = __iio_dmaengine_buffer_setup_ext(indio_dev, chan, dir);
+ buffer = __iio_dmaengine_buffer_setup_ext(indio_dev, chan, dir, buffer_attrs);
if (IS_ERR(buffer))
return PTR_ERR(buffer);
diff --git a/drivers/iio/dac/ad5791.c b/drivers/iio/dac/ad5791.c
index ae7297f08398..024607adb915 100644
--- a/drivers/iio/dac/ad5791.c
+++ b/drivers/iio/dac/ad5791.c
@@ -448,7 +448,7 @@ static int ad5791_offload_setup(struct iio_dev *indio_dev)
"failed to get offload TX DMA\n");
ret = devm_iio_dmaengine_buffer_setup_with_handle(&spi->dev,
- indio_dev, tx_dma, IIO_BUFFER_DIRECTION_OUT);
+ indio_dev, tx_dma, IIO_BUFFER_DIRECTION_OUT, NULL);
if (ret)
return ret;
diff --git a/drivers/iio/dac/ad8460.c b/drivers/iio/dac/ad8460.c
index 6e45686902dd..3c5fd71d5add 100644
--- a/drivers/iio/dac/ad8460.c
+++ b/drivers/iio/dac/ad8460.c
@@ -921,7 +921,7 @@ static int ad8460_probe(struct spi_device *spi)
indio_dev->setup_ops = &ad8460_buffer_setup_ops;
ret = devm_iio_dmaengine_buffer_setup_ext(dev, indio_dev, "tx",
- IIO_BUFFER_DIRECTION_OUT);
+ IIO_BUFFER_DIRECTION_OUT, NULL);
if (ret)
return dev_err_probe(dev, ret,
"Failed to get DMA buffer\n");
diff --git a/drivers/iio/dac/adi-axi-dac.c b/drivers/iio/dac/adi-axi-dac.c
index 451fad34e7ee..23028a92ceba 100644
--- a/drivers/iio/dac/adi-axi-dac.c
+++ b/drivers/iio/dac/adi-axi-dac.c
@@ -162,7 +162,7 @@ static struct iio_buffer *axi_dac_request_buffer(struct iio_backend *back,
dma_name = "tx";
return iio_dmaengine_buffer_setup_ext(st->dev, indio_dev, dma_name,
- IIO_BUFFER_DIRECTION_OUT);
+ IIO_BUFFER_DIRECTION_OUT, NULL);
}
static void axi_dac_free_buffer(struct iio_backend *back,
diff --git a/include/linux/iio/buffer-dmaengine.h b/include/linux/iio/buffer-dmaengine.h
index 37f27545f69f..bb7a348db72d 100644
--- a/include/linux/iio/buffer-dmaengine.h
+++ b/include/linux/iio/buffer-dmaengine.h
@@ -10,6 +10,7 @@
#include <linux/iio/buffer.h>
struct iio_dev;
+struct iio_dev_attr;
struct device;
struct dma_chan;
@@ -17,23 +18,26 @@ void iio_dmaengine_buffer_teardown(struct iio_buffer *buffer);
struct iio_buffer *iio_dmaengine_buffer_setup_ext(struct device *dev,
struct iio_dev *indio_dev,
const char *channel,
- enum iio_buffer_direction dir);
+ enum iio_buffer_direction dir,
+ const struct iio_dev_attr **buffer_attrs);
#define iio_dmaengine_buffer_setup(dev, indio_dev, channel) \
- iio_dmaengine_buffer_setup_ext(dev, indio_dev, channel, \
- IIO_BUFFER_DIRECTION_IN)
+ iio_dmaengine_buffer_setup_ext(dev, indio_dev, channel, \
+ IIO_BUFFER_DIRECTION_IN, NULL)
int devm_iio_dmaengine_buffer_setup_ext(struct device *dev,
struct iio_dev *indio_dev,
const char *channel,
- enum iio_buffer_direction dir);
+ enum iio_buffer_direction dir,
+ const struct iio_dev_attr **buffer_attrs);
int devm_iio_dmaengine_buffer_setup_with_handle(struct device *dev,
struct iio_dev *indio_dev,
struct dma_chan *chan,
- enum iio_buffer_direction dir);
+ enum iio_buffer_direction dir,
+ const struct iio_dev_attr **buffer_attrs);
#define devm_iio_dmaengine_buffer_setup(dev, indio_dev, channel) \
devm_iio_dmaengine_buffer_setup_ext(dev, indio_dev, channel, \
- IIO_BUFFER_DIRECTION_IN)
+ IIO_BUFFER_DIRECTION_IN, NULL)
#endif
--
2.53.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 4/5] iio: adc: ltc2378: Enable high-speed data capture
2026-06-17 2:02 [PATCH v3 0/5] iio: adc: Add support for LTC2378 and similar ADCs Marcelo Schmitt
` (2 preceding siblings ...)
2026-06-17 2:03 ` [RFC PATCH v3 3/5] iio: buffer: Extend DMAengine buffer interfaces to take extra sysfs attributes Marcelo Schmitt
@ 2026-06-17 2:04 ` Marcelo Schmitt
2026-06-17 2:04 ` [PATCH v3 5/5] iio: adc: ltc2378: Enable triggered buffer " Marcelo Schmitt
4 siblings, 0 replies; 6+ messages in thread
From: Marcelo Schmitt @ 2026-06-17 2:04 UTC (permalink / raw)
To: linux-iio, devicetree, linux-kernel
Cc: jic23, nuno.sa, Michael.Hennerich, dlechner, andy, robh, krzk+dt,
conor+dt, pop.ioan-daniel, marcelo.schmitt1
Make use of SPI transfer offloading to speed up data capture, enabling data
acquisition at faster sample rates (up to 2 MSPS).
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v2 -> v3:
- Fixed the evaluation loop conditions for CNV PWM and SPI Engine trigger PWM,
avoiding potential infinite loop if and CPU stall.
- Added comment to about initial PWM disable.
- Adjusted SPI offload setup initialization to not print error on a valid condition.
- Fully initialize IIO channel scan_type.
- Reworked to make offload support not imply all dependencies to be built in.
- Made sampling_frequency a buffer attribute.
- Made offload support not require DMA and other features to be built in.
- Now using same scan_type configuration for all use cases.
drivers/iio/adc/Kconfig | 19 ++
drivers/iio/adc/Makefile | 6 +
drivers/iio/adc/ltc2378-lib-core.c | 35 +++
drivers/iio/adc/ltc2378-offload-buffer.c | 305 +++++++++++++++++++++++
drivers/iio/adc/ltc2378.c | 46 ++++
drivers/iio/adc/ltc2378.h | 42 ++++
6 files changed, 453 insertions(+)
create mode 100644 drivers/iio/adc/ltc2378-lib-core.c
create mode 100644 drivers/iio/adc/ltc2378-offload-buffer.c
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 2b8203451367..f96d9262b891 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -944,6 +944,9 @@ config LTC2378
tristate "Analog Devices LTC2378 ADC driver"
depends on SPI
depends on GPIOLIB
+ select LTC2378_LIB
+ select LTC2378_LIB_OFFLOAD_BUFFER if SPI_OFFLOAD && PWM && SPI_OFFLOAD_TRIGGER_PWM && IIO_BUFFER && IIO_BUFFER_DMAENGINE
+ select LTC2378_LIB_TRIGGERED_BUFFER if IIO_BUFFER
help
Say yes here to build support for Analog Devices LTC2378-20 and
similar analog to digital converters.
@@ -2027,3 +2030,19 @@ config XILINX_AMS
xilinx-ams.
endmenu
+
+config LTC2378_LIB
+ tristate
+ help
+ Say yes here to build support for buffered data capture with LTC2378
+
+config LTC2378_LIB_OFFLOAD_BUFFER
+ bool
+ help
+ Say yes here to build support for high speed data capture with LTC2378
+
+config LTC2378_LIB_TRIGGERED_BUFFER
+ bool
+ select IIO_TRIGGERED_BUFFER
+ help
+ Say yes here to build support for buffered data capture with LTC2378
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 1814fb78dde3..109cd39237c9 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -82,6 +82,12 @@ obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
obj-$(CONFIG_LTC2309) += ltc2309.o
obj-$(CONFIG_LTC2378) += ltc2378.o
+
+ltc2378_lib-y += ltc2378-lib-core.o
+ltc2378_lib-$(CONFIG_LTC2378_LIB_OFFLOAD_BUFFER) += ltc2378-offload-buffer.o
+ltc2378_lib-$(CONFIG_LTC2378_LIB_TRIGGERED_BUFFER) += ltc2378-triggered-buffer.o
+obj-$(CONFIG_LTC2378_LIB) += ltc2378_lib.o
+
obj-$(CONFIG_LTC2471) += ltc2471.o
obj-$(CONFIG_LTC2485) += ltc2485.o
obj-$(CONFIG_LTC2496) += ltc2496.o ltc2497-core.o
diff --git a/drivers/iio/adc/ltc2378-lib-core.c b/drivers/iio/adc/ltc2378-lib-core.c
new file mode 100644
index 000000000000..1160f4324d01
--- /dev/null
+++ b/drivers/iio/adc/ltc2378-lib-core.c
@@ -0,0 +1,35 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Analog Devices LTC2378 ADC series driver
+ *
+ * Copyright (C) 2026 Analog Devices Inc.
+ * Author: Marcelo Schmitt <marcelo.schmitt@analog.com>
+ */
+
+#include <linux/err.h>
+#include <linux/iio/iio.h>
+
+#include "ltc2378.h"
+
+int ltc2378_lib_buffer_setup(struct iio_dev *indio_dev, struct ltc2378_state *st)
+{
+ struct device *dev = &st->spi->dev;
+ int ret;
+
+ ret = __ltc2378_set_offload_ops(st);
+ if (ret == -EOPNOTSUPP)
+ return 0; /* Let device setup complete without buffer support */
+
+ if (!ret)
+ ret = st->ops->buffer_setup(indio_dev, st);
+
+ if (ret)
+ return dev_err_probe(dev, ret, "error on SPI offload setup\n");
+
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(ltc2378_lib_buffer_setup, "IIO_LTC2378");
+
+MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt@analog.com>");
+MODULE_DESCRIPTION("Analog Devices LTC2378 ADC series driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/adc/ltc2378-offload-buffer.c b/drivers/iio/adc/ltc2378-offload-buffer.c
new file mode 100644
index 000000000000..3e8c7ab64a54
--- /dev/null
+++ b/drivers/iio/adc/ltc2378-offload-buffer.c
@@ -0,0 +1,305 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2026 Analog Devices, Inc.
+ * Author: Marcelo Schmitt <marcelo.schmitt@analog.com>
+ */
+
+#include <linux/cleanup.h>
+#include <linux/err.h>
+#include <linux/math.h>
+#include <linux/math64.h>
+#include <linux/pwm.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/offload/consumer.h>
+#include <linux/spi/offload/types.h>
+#include <linux/time64.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/buffer-dmaengine.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/types.h>
+
+#include "ltc2378.h"
+
+/*
+ * SPI offload wiring schema
+ *
+ * +-------------+ +-------------+
+ * | CNV |<-----+--| GPIO |
+ * | | +--| PWM0 |
+ * | | | |
+ * | | +--| PWM1 |
+ * | | | +-------------+
+ * | | +->| TRIGGER |
+ * | | | |
+ * | ADC | | SPI |
+ * | | | controller |
+ * | | | |
+ * | SDI |<--------| SDO |
+ * | SDO |-------->| SDI |
+ * | SCLK |<--------| SCLK |
+ * +-------------+ +-------------+
+ *
+ */
+static int ltc2378_update_conversion_rate(struct ltc2378_state *st, int freq_Hz)
+{
+ struct spi_offload_trigger_config *config = &st->offload_trigger_config;
+ unsigned int min_read_offset, offload_period_ns;
+ struct pwm_waveform cnv_wf = { };
+ u64 target = LTC2378_TCNV_HIGH_NS;
+ unsigned int count = 0;
+ u64 offload_offset_ns;
+ int ret;
+
+ if (freq_Hz == 0)
+ return -EINVAL;
+
+ if (freq_Hz < 1 || freq_Hz > st->info->max_sample_rate_hz)
+ return -ERANGE;
+
+ /* Configure CNV PWM waveform */
+ cnv_wf.period_length_ns = DIV_ROUND_CLOSEST(NSEC_PER_SEC, freq_Hz);
+
+ /*
+ * Ensure CNV high time meets minimum requirement (20ns). The PWM
+ * hardware may round the duty cycle, so iterate until we get at least
+ * the minimum required high time.
+ */
+ do {
+ cnv_wf.duty_length_ns = target;
+ ret = pwm_round_waveform_might_sleep(st->cnv_trigger, &cnv_wf);
+ if (ret)
+ return ret;
+ target += 10; /* Increment by PWM duty cycle period */
+ } while (count++ < 100 && cnv_wf.duty_length_ns < LTC2378_TCNV_HIGH_NS);
+
+ /* Double check the minimum CNV high time is met */
+ if (cnv_wf.duty_length_ns < LTC2378_TCNV_HIGH_NS)
+ return -EIO;
+
+ /*
+ * Configure SPI offload PWM trigger.
+ * The trigger should fire after tBUSYLH + tCONV + tDSDOBUSYL.
+ * Minimum time needed: TBUSYLH (13ns) + TCONV (part-specific) + TDSDOBUSYL (5ns)
+ *
+ * Use the same period as CNV PWM to avoid timing issues.
+ * Convert back from period to frequency for the SPI offload API.
+ */
+ offload_period_ns = cnv_wf.period_length_ns;
+ config->periodic.frequency_hz = DIV_ROUND_UP(HZ_PER_GHZ, offload_period_ns);
+ min_read_offset = LTC2378_TBUSYLH_NS + st->info->tconv_ns + LTC2378_TDSDOBUSYL_NS;
+ offload_offset_ns = min_read_offset;
+ count = 0;
+ do {
+ config->periodic.offset_ns = offload_offset_ns;
+ ret = spi_offload_trigger_validate(st->offload_trigger, config);
+ if (ret)
+ return ret;
+ offload_offset_ns += 10;
+ } while (count++ < 100 && config->periodic.offset_ns < min_read_offset);
+
+ st->cnv_wf = cnv_wf;
+ st->cnv_Hz = DIV_ROUND_CLOSEST_ULL(HZ_PER_GHZ, cnv_wf.period_length_ns);
+
+ return 0;
+}
+
+static ssize_t sampling_frequency_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ltc2378_state *st = iio_priv(dev_to_iio_dev(dev));
+
+ return sysfs_emit(buf, "%u\n", st->cnv_Hz);
+}
+
+static ssize_t sampling_frequency_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ltc2378_state *st = iio_priv(indio_dev);
+ unsigned int val;
+ int ret;
+
+ IIO_DEV_ACQUIRE_DIRECT_MODE(indio_dev, claim);
+ if (IIO_DEV_ACQUIRE_FAILED(claim))
+ return -EBUSY;
+
+ ret = kstrtouint(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ ret = ltc2378_update_conversion_rate(st, val);
+
+ return ret ?: len;
+}
+
+static ssize_t sampling_frequency_available_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ltc2378_state *st = iio_priv(indio_dev);
+
+ return sysfs_emit(buf, "[%u %u %u]\n",
+ 1, 1, st->info->max_sample_rate_hz);
+}
+
+static IIO_DEVICE_ATTR_RO(sampling_frequency_available, 0);
+static IIO_DEVICE_ATTR(sampling_frequency, 0644,
+ sampling_frequency_show, sampling_frequency_store, 0);
+
+static const struct iio_dev_attr *ltc2378_offload_buffer_attrs[] = {
+ &iio_dev_attr_sampling_frequency_available,
+ &iio_dev_attr_sampling_frequency,
+ NULL
+};
+
+static int ltc2378_prepare_offload_message(struct device *dev,
+ struct ltc2378_state *st)
+{
+ st->offload_xfer.bits_per_word = st->info->resolution;
+ st->offload_xfer.len = st->info->resolution > 16 ? 4 : 2;
+ st->offload_xfer.offload_flags = SPI_OFFLOAD_XFER_RX_STREAM;
+
+ /* Initialize message with offload */
+ spi_message_init_with_transfers(&st->offload_msg, &st->offload_xfer, 1);
+ st->offload_msg.offload = st->offload;
+
+ return devm_spi_optimize_message(dev, st->spi, &st->offload_msg);
+}
+
+static int ltc2378_offload_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct ltc2378_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = pwm_set_waveform_might_sleep(st->cnv_trigger, &st->cnv_wf, false);
+ if (ret)
+ return ret;
+
+ ret = spi_offload_trigger_enable(st->offload, st->offload_trigger,
+ &st->offload_trigger_config);
+ if (ret)
+ goto out_pwm_disable;
+
+ return 0;
+
+out_pwm_disable:
+ pwm_disable(st->cnv_trigger);
+ return ret;
+}
+
+static int ltc2378_offload_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct ltc2378_state *st = iio_priv(indio_dev);
+
+ spi_offload_trigger_disable(st->offload, st->offload_trigger);
+ pwm_disable(st->cnv_trigger);
+
+ return 0;
+}
+
+static const struct iio_buffer_setup_ops ltc2378_offload_buffer_ops = {
+ .postenable = <c2378_offload_buffer_postenable,
+ .predisable = <c2378_offload_buffer_predisable,
+};
+
+static int ltc2378_spi_offload_setup(struct iio_dev *indio_dev,
+ struct ltc2378_state *st)
+{
+ struct device *dev = &st->spi->dev;
+ struct dma_chan *rx_dma;
+
+ indio_dev->setup_ops = <c2378_offload_buffer_ops;
+
+ st->offload_trigger = devm_spi_offload_trigger_get(dev, st->offload,
+ SPI_OFFLOAD_TRIGGER_PERIODIC);
+ if (IS_ERR(st->offload_trigger))
+ return dev_err_probe(dev, PTR_ERR(st->offload_trigger),
+ "failed to get offload trigger\n");
+
+ st->offload_trigger_config.type = SPI_OFFLOAD_TRIGGER_PERIODIC;
+
+ rx_dma = devm_spi_offload_rx_stream_request_dma_chan(dev, st->offload);
+ if (IS_ERR(rx_dma))
+ return dev_err_probe(dev, PTR_ERR(rx_dma), "failed to get offload RX DMA\n");
+
+ return devm_iio_dmaengine_buffer_setup_with_handle(dev, indio_dev, rx_dma,
+ IIO_BUFFER_DIRECTION_IN,
+ ltc2378_offload_buffer_attrs);
+}
+
+static int ltc2378_pwm_get(struct ltc2378_state *st)
+{
+ struct device *dev = &st->spi->dev;
+
+ st->cnv_trigger = devm_pwm_get(dev, NULL);
+ if (IS_ERR(st->cnv_trigger))
+ return dev_err_probe(dev, PTR_ERR(st->cnv_trigger),
+ "failed to get cnv pwm\n");
+
+ /*
+ * Disable the PWM connected to CNV in case it was left running by
+ * something else.
+ */
+ pwm_disable(st->cnv_trigger);
+
+ return 0;
+}
+
+static const struct spi_offload_config ltc2378_offload_config = {
+ .capability_flags = SPI_OFFLOAD_CAP_TRIGGER |
+ SPI_OFFLOAD_CAP_RX_STREAM_DMA,
+};
+
+static int ltc2378_offload_buffer_setup(struct iio_dev *indio_dev,
+ struct ltc2378_state *st)
+{
+ struct spi_device *spi = st->spi;
+ struct device *dev = &spi->dev;
+ int ret;
+
+ st->offload = devm_spi_offload_get(dev, spi, <c2378_offload_config);
+ ret = PTR_ERR_OR_ZERO(st->offload);
+ if (ret)
+ return ret;
+
+ ret = ltc2378_spi_offload_setup(indio_dev, st);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "failed to setup SPI offload\n");
+
+ ret = ltc2378_pwm_get(st);
+ if (ret)
+ return ret;
+
+ /*
+ * Start with a slower sampling rate so there is some room for
+ * adjusting the sampling frequency without hitting the maximum
+ * conversion rate.
+ */
+ ret = ltc2378_update_conversion_rate(st, st->info->max_sample_rate_hz >> 4);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to sampling frequency\n");
+
+ ret = ltc2378_prepare_offload_message(&spi->dev, st);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to optimize SPI message\n");
+
+ return 0;
+}
+
+static const struct ltc2378_ops ltc2378_offload_ops = {
+ .buffer_setup = ltc2378_offload_buffer_setup,
+};
+
+int ltc2378_set_offload_ops(struct ltc2378_state *st)
+{
+ st->ops = <c2378_offload_ops;
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(ltc2378_set_offload_ops, "IIO_LTC2378");
+
+MODULE_IMPORT_NS("IIO_DMAENGINE_BUFFER");
diff --git a/drivers/iio/adc/ltc2378.c b/drivers/iio/adc/ltc2378.c
index 88582bdcd6a6..bf17b202230b 100644
--- a/drivers/iio/adc/ltc2378.c
+++ b/drivers/iio/adc/ltc2378.c
@@ -17,6 +17,7 @@
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
#include <linux/types.h>
+#include <linux/units.h>
#include <linux/iio/iio.h>
#include <linux/iio/types.h>
@@ -26,120 +27,160 @@
static const struct ltc2378_chip_info ltc2338_18_chip_info = {
.name = "ltc2338-18",
.resolution = 18,
+ .max_sample_rate_hz = HZ_PER_MHZ,
+ .tconv_ns = 527,
.bipolar = true,
};
static const struct ltc2378_chip_info ltc2364_16_chip_info = {
.name = "ltc2364-16",
.resolution = 16,
+ .max_sample_rate_hz = 250 * HZ_PER_KHZ,
+ .tconv_ns = 3000,
.bipolar = false,
};
static const struct ltc2378_chip_info ltc2364_18_chip_info = {
.name = "ltc2364-18",
.resolution = 18,
+ .max_sample_rate_hz = 250 * HZ_PER_KHZ,
+ .tconv_ns = 3000,
.bipolar = false,
};
static const struct ltc2378_chip_info ltc2367_16_chip_info = {
.name = "ltc2367-16",
.resolution = 16,
+ .max_sample_rate_hz = 500 * HZ_PER_KHZ,
+ .tconv_ns = 1500,
.bipolar = false,
};
static const struct ltc2378_chip_info ltc2367_18_chip_info = {
.name = "ltc2367-18",
.resolution = 18,
+ .max_sample_rate_hz = 500 * HZ_PER_KHZ,
+ .tconv_ns = 1500,
.bipolar = false,
};
static const struct ltc2378_chip_info ltc2368_16_chip_info = {
.name = "ltc2368-16",
.resolution = 16,
+ .max_sample_rate_hz = HZ_PER_MHZ,
+ .tconv_ns = 527,
.bipolar = false,
};
static const struct ltc2378_chip_info ltc2368_18_chip_info = {
.name = "ltc2368-18",
.resolution = 18,
+ .max_sample_rate_hz = HZ_PER_MHZ,
+ .tconv_ns = 527,
.bipolar = false,
};
static const struct ltc2378_chip_info ltc2369_18_chip_info = {
.name = "ltc2369-18",
.resolution = 18,
+ .max_sample_rate_hz = 1600 * HZ_PER_KHZ,
+ .tconv_ns = 412,
.bipolar = false,
};
static const struct ltc2378_chip_info ltc2370_16_chip_info = {
.name = "ltc2370-16",
.resolution = 16,
+ .max_sample_rate_hz = 2 * HZ_PER_MHZ,
+ .tconv_ns = 322,
.bipolar = false,
};
static const struct ltc2378_chip_info ltc2376_16_chip_info = {
.name = "ltc2376-16",
.resolution = 16,
+ .max_sample_rate_hz = 250 * HZ_PER_KHZ,
+ .tconv_ns = 3000,
.bipolar = true,
};
static const struct ltc2378_chip_info ltc2376_18_chip_info = {
.name = "ltc2376-18",
.resolution = 18,
+ .max_sample_rate_hz = 250 * HZ_PER_KHZ,
+ .tconv_ns = 3000,
.bipolar = true,
};
static const struct ltc2378_chip_info ltc2376_20_chip_info = {
.name = "ltc2376-20",
.resolution = 20,
+ .max_sample_rate_hz = 250 * HZ_PER_KHZ,
+ .tconv_ns = 3000,
.bipolar = true,
};
static const struct ltc2378_chip_info ltc2377_16_chip_info = {
.name = "ltc2377-16",
.resolution = 16,
+ .max_sample_rate_hz = 500 * HZ_PER_KHZ,
+ .tconv_ns = 1500,
.bipolar = true,
};
static const struct ltc2378_chip_info ltc2377_18_chip_info = {
.name = "ltc2377-18",
.resolution = 18,
+ .max_sample_rate_hz = 500 * HZ_PER_KHZ,
+ .tconv_ns = 1500,
.bipolar = true,
};
static const struct ltc2378_chip_info ltc2377_20_chip_info = {
.name = "ltc2377-20",
.resolution = 20,
+ .max_sample_rate_hz = 500 * HZ_PER_KHZ,
+ .tconv_ns = 1500,
.bipolar = true,
};
static const struct ltc2378_chip_info ltc2378_16_chip_info = {
.name = "ltc2378-16",
.resolution = 16,
+ .max_sample_rate_hz = HZ_PER_MHZ,
+ .tconv_ns = 527,
.bipolar = true,
};
static const struct ltc2378_chip_info ltc2378_18_chip_info = {
.name = "ltc2378-18",
.resolution = 18,
+ .max_sample_rate_hz = HZ_PER_MHZ,
+ .tconv_ns = 527,
.bipolar = true,
};
static const struct ltc2378_chip_info ltc2378_20_chip_info = {
.name = "ltc2378-20",
.resolution = 20,
+ .max_sample_rate_hz = HZ_PER_MHZ,
+ .tconv_ns = 675,
.bipolar = true,
};
static const struct ltc2378_chip_info ltc2379_18_chip_info = {
.name = "ltc2379-18",
.resolution = 18,
+ .max_sample_rate_hz = 1600 * HZ_PER_KHZ,
+ .tconv_ns = 412,
.bipolar = true,
};
static const struct ltc2378_chip_info ltc2380_16_chip_info = {
.name = "ltc2380-16",
.resolution = 16,
+ .max_sample_rate_hz = 2 * HZ_PER_MHZ,
+ .tconv_ns = 322,
.bipolar = true,
};
@@ -266,6 +307,10 @@ static int ltc2378_probe(struct spi_device *spi)
st->xfer.len = st->info->resolution > 16 ? 4 : 2;
st->xfer.bits_per_word = st->info->resolution;
+ ret = ltc2378_lib_buffer_setup(indio_dev, st);
+ if (ret)
+ return ret;
+
indio_dev->channels = st->chans;
indio_dev->num_channels = st->num_iio_chans;
@@ -336,3 +381,4 @@ MODULE_AUTHOR("Ioan-Daniel Pop <pop.ioan-daniel@analog.com>");
MODULE_AUTHOR("Marcelo Schmitt <marcelo.schmitt@analog.com>");
MODULE_DESCRIPTION("Analog Devices LTC2378 ADC series driver");
MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("IIO_LTC2378");
diff --git a/drivers/iio/adc/ltc2378.h b/drivers/iio/adc/ltc2378.h
index a3a69351de6c..f6e10f9a83e0 100644
--- a/drivers/iio/adc/ltc2378.h
+++ b/drivers/iio/adc/ltc2378.h
@@ -8,10 +8,14 @@
#ifndef __DRIVERS_IIO_ADC_LTC2378_H__
#define __DRIVERS_IIO_ADC_LTC2378_H__
+#include <linux/errno.h>
#include <linux/iio/iio.h>
#include <linux/gpio/consumer.h>
#include <linux/delay.h>
+#include <linux/pwm.h>
#include <linux/spi/spi.h>
+#include <linux/spi/offload/consumer.h>
+#include <linux/spi/offload/types.h>
#include <linux/types.h>
#include <linux/units.h>
@@ -19,12 +23,24 @@
#define LTC2378_TBUSYLH_NS 13
#define LTC2378_TCNV_HIGH_NS 20
+struct ltc2378_state;
+
struct ltc2378_chip_info {
const char *name;
int resolution;
+ unsigned int max_sample_rate_hz;
+ unsigned int tconv_ns;
bool bipolar;
};
+/**
+ * struct ltc2378_ops: Setup specific procedures for ltc2378 devices.
+ * @ltc2378_buffer_setup: Custom buffer setup implementation.
+ */
+struct ltc2378_ops {
+ int (*buffer_setup)(struct iio_dev *indio_dev, struct ltc2378_state *st);
+};
+
struct ltc2378_state {
const struct ltc2378_chip_info *info;
struct gpio_desc *cnv_gpio;
@@ -33,6 +49,15 @@ struct ltc2378_state {
unsigned int num_iio_chans;
struct iio_chan_spec chans[2]; /* 1 physical chan + 1 timestamp chan */
int ref_uV;
+ const struct ltc2378_ops *ops;
+ unsigned int cnv_Hz;
+ struct pwm_waveform cnv_wf;
+ struct spi_offload *offload;
+ struct spi_offload_trigger *offload_trigger;
+ struct spi_message offload_msg;
+ struct spi_transfer offload_xfer;
+ struct spi_offload_trigger_config offload_trigger_config;
+ struct pwm_device *cnv_trigger;
/*
* DMA (thus cache coherency maintenance) requires the
@@ -60,4 +85,21 @@ static inline int ltc2378_convert_and_acquire(struct ltc2378_state *st)
return ret;
}
+int ltc2378_lib_buffer_setup(struct iio_dev *indio_dev, struct ltc2378_state *st);
+
+#define __ltc2378_set_offload_ops(st) ltc2378_set_offload_ops((st))
+
+#ifdef CONFIG_LTC2378_LIB_OFFLOAD_BUFFER
+
+int ltc2378_set_offload_ops(struct ltc2378_state *st);
+
+#else
+
+static inline int ltc2378_set_offload_ops(struct ltc2378_state *st)
+{
+ return -EOPNOTSUPP;
+}
+
+#endif /* CONFIG_LTC2378_LIB_OFFLOAD_BUFFER */
+
#endif /* __DRIVERS_IIO_ADC_LTC2378_H__ */
--
2.53.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 5/5] iio: adc: ltc2378: Enable triggered buffer data capture
2026-06-17 2:02 [PATCH v3 0/5] iio: adc: Add support for LTC2378 and similar ADCs Marcelo Schmitt
` (3 preceding siblings ...)
2026-06-17 2:04 ` [PATCH v3 4/5] iio: adc: ltc2378: Enable high-speed data capture Marcelo Schmitt
@ 2026-06-17 2:04 ` Marcelo Schmitt
4 siblings, 0 replies; 6+ messages in thread
From: Marcelo Schmitt @ 2026-06-17 2:04 UTC (permalink / raw)
To: linux-iio, devicetree, linux-kernel
Cc: jic23, nuno.sa, Michael.Hennerich, dlechner, andy, robh, krzk+dt,
conor+dt, pop.ioan-daniel, marcelo.schmitt1
Enable users to run triggered data captures with LTC2378 and similar ADCs.
Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
---
Change log v2 -> v3:
- Extracted from main driver file into a separate buffer-specific containment.
drivers/iio/adc/ltc2378-lib-core.c | 17 +++++++-
drivers/iio/adc/ltc2378-triggered-buffer.c | 49 ++++++++++++++++++++++
drivers/iio/adc/ltc2378.h | 15 +++++++
3 files changed, 80 insertions(+), 1 deletion(-)
create mode 100644 drivers/iio/adc/ltc2378-triggered-buffer.c
diff --git a/drivers/iio/adc/ltc2378-lib-core.c b/drivers/iio/adc/ltc2378-lib-core.c
index 1160f4324d01..ec83e9f2ae81 100644
--- a/drivers/iio/adc/ltc2378-lib-core.c
+++ b/drivers/iio/adc/ltc2378-lib-core.c
@@ -18,7 +18,7 @@ int ltc2378_lib_buffer_setup(struct iio_dev *indio_dev, struct ltc2378_state *st
ret = __ltc2378_set_offload_ops(st);
if (ret == -EOPNOTSUPP)
- return 0; /* Let device setup complete without buffer support */
+ goto trigger_buf_setup;
if (!ret)
ret = st->ops->buffer_setup(indio_dev, st);
@@ -27,6 +27,21 @@ int ltc2378_lib_buffer_setup(struct iio_dev *indio_dev, struct ltc2378_state *st
return dev_err_probe(dev, ret, "error on SPI offload setup\n");
return 0;
+
+trigger_buf_setup:
+ ret = __ltc2378_set_triggered_buf_ops(st);
+ if (ret == -EOPNOTSUPP)
+ return 0; /* Let device setup complete without buffer support */
+
+ if (!ret)
+ ret = st->ops->buffer_setup(indio_dev, st);
+
+ if (ret)
+ return dev_err_probe(dev, ret, "error on buffer setup\n");
+
+ st->chans[st->num_iio_chans++] = IIO_CHAN_SOFT_TIMESTAMP(1);
+
+ return 0;
}
EXPORT_SYMBOL_NS_GPL(ltc2378_lib_buffer_setup, "IIO_LTC2378");
diff --git a/drivers/iio/adc/ltc2378-triggered-buffer.c b/drivers/iio/adc/ltc2378-triggered-buffer.c
new file mode 100644
index 000000000000..d1d788fb5cb4
--- /dev/null
+++ b/drivers/iio/adc/ltc2378-triggered-buffer.c
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2026 Analog Devices, Inc.
+ * Author: Marcelo Schmitt <marcelo.schmitt@analog.com>
+ */
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#include <ltc2378.h>
+
+static irqreturn_t ltc2378_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct ltc2378_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = ltc2378_convert_and_acquire(st);
+ if (ret < 0)
+ goto err_out;
+
+ iio_push_to_buffers_with_ts(indio_dev, &st->scan, sizeof(st->scan),
+ pf->timestamp);
+
+err_out:
+ iio_trigger_notify_done(indio_dev->trig);
+ return IRQ_HANDLED;
+}
+
+static int ltc2378_triggered_buffer_setup(struct iio_dev *indio_dev, struct ltc2378_state *st)
+{
+ return devm_iio_triggered_buffer_setup(&st->spi->dev, indio_dev,
+ &iio_pollfunc_store_time,
+ <c2378_trigger_handler,
+ NULL);
+}
+
+static const struct ltc2378_ops ltc2378_triggered_buf_ops = {
+ .buffer_setup = ltc2378_triggered_buffer_setup,
+};
+
+int ltc2378_set_triggered_buf_ops(struct ltc2378_state *st)
+{
+ st->ops = <c2378_triggered_buf_ops;
+ return 0;
+}
+EXPORT_SYMBOL_NS_GPL(ltc2378_set_triggered_buf_ops, "IIO_LTC2378");
diff --git a/drivers/iio/adc/ltc2378.h b/drivers/iio/adc/ltc2378.h
index f6e10f9a83e0..4241b1e79ac0 100644
--- a/drivers/iio/adc/ltc2378.h
+++ b/drivers/iio/adc/ltc2378.h
@@ -89,6 +89,8 @@ int ltc2378_lib_buffer_setup(struct iio_dev *indio_dev, struct ltc2378_state *st
#define __ltc2378_set_offload_ops(st) ltc2378_set_offload_ops((st))
+#define __ltc2378_set_triggered_buf_ops(st) ltc2378_set_triggered_buf_ops((st))
+
#ifdef CONFIG_LTC2378_LIB_OFFLOAD_BUFFER
int ltc2378_set_offload_ops(struct ltc2378_state *st);
@@ -102,4 +104,17 @@ static inline int ltc2378_set_offload_ops(struct ltc2378_state *st)
#endif /* CONFIG_LTC2378_LIB_OFFLOAD_BUFFER */
+#ifdef CONFIG_LTC2378_LIB_TRIGGERED_BUFFER
+
+int ltc2378_set_triggered_buf_ops(struct ltc2378_state *st);
+
+#else
+
+static inline int ltc2378_set_triggered_buf_ops(struct ltc2378_state *st)
+{
+ return -EOPNOTSUPP;
+}
+
+#endif /* CONFIG_LTC2378_LIB_TRIGGERED_BUFFER */
+
#endif /* __DRIVERS_IIO_ADC_LTC2378_H__ */
--
2.53.0
^ permalink raw reply related [flat|nested] 6+ messages in thread