--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Maxim MAX11205 16-Bit Delta-Sigma ADC
+ *
+ * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-max11205.pdf
+ * Copyright (C) 2022 Analog Devices, Inc.
+ * Author: Ramona Bolboaca <ramona.bolboaca@analog.com>
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/adc/ad_sigma_delta.h>
+
+#define MAX11205_BIT_SCALE 15
+#define MAX11205A_OUT_DATA_RATE 116
+#define MAX11205B_OUT_DATA_RATE 13
+
+enum max11205_chip_type {
+ TYPE_MAX11205A,
+ TYPE_MAX11205B,
+};
+
+struct max11205_chip_info {
+ unsigned int out_data_rate;
+ const char *name;
+};
+
+struct max11205_state {
+ const struct max11205_chip_info *chip_info;
+ struct regulator *vref;
+ struct ad_sigma_delta sd;
+};
+
+static const struct ad_sigma_delta_info max11205_sigma_delta_info = {
+ .has_registers = false,
+};
+
+static int max11205_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct max11205_state *st = iio_priv(indio_dev);
+ int reg_mv;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ return ad_sigma_delta_single_conversion(indio_dev, chan, val);
+ case IIO_CHAN_INFO_SCALE:
+ reg_mv = regulator_get_voltage(st->vref);
+ if (reg_mv < 0)
+ return reg_mv;
+ reg_mv /= 1000;
+ *val = reg_mv;
+ *val2 = MAX11205_BIT_SCALE;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = st->chip_info->out_data_rate;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info max11205_iio_info = {
+ .read_raw = max11205_read_raw,
+ .validate_trigger = ad_sd_validate_trigger,
+};
+
+static const struct iio_chan_spec max11205_channels[] = {
+ {
+ .type = IIO_VOLTAGE,
+ .indexed = 1,
+ .scan_type = {
+ .sign = 's',
+ .realbits = 16,
+ .storagebits = 16,
+ .endianness = IIO_BE,
+ },
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ },
+};
+
+static const struct max11205_chip_info max11205_chip_info[] = {
+ [TYPE_MAX11205A] = {
+ .out_data_rate = MAX11205A_OUT_DATA_RATE,
+ .name = "max11205a",
+ },
+ [TYPE_MAX11205B] = {
+ .out_data_rate = MAX11205B_OUT_DATA_RATE,
+ .name = "max11205b",
+ },
+};
+
+static void max11205_reg_disable(void *reg)
+{
+ regulator_disable(reg);
+}
+
+static int max11205_probe(struct spi_device *spi)
+{
+ struct max11205_state *st;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+
+ ad_sd_init(&st->sd, indio_dev, spi, &max11205_sigma_delta_info);
+
+ st->chip_info = device_get_match_data(&spi->dev);
+ if (!st->chip_info)
+ st->chip_info =
+ (const struct max11205_chip_info *)spi_get_device_id(spi)->driver_data;
+
+ indio_dev->name = st->chip_info->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = max11205_channels;
+ indio_dev->num_channels = 1;
+ indio_dev->info = &max11205_iio_info;
+
+ st->vref = devm_regulator_get(&spi->dev, "vref");
+ if (IS_ERR(st->vref))
+ return dev_err_probe(&spi->dev, PTR_ERR(st->vref),
+ "Failed to get vref regulator\n");
+
+ ret = regulator_enable(st->vref);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(&spi->dev, max11205_reg_disable, st->vref);
+ if (ret)
+ return ret;
+
+ ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id max11205_spi_ids[] = {
+ { "max11205a", (kernel_ulong_t)&max11205_chip_info[TYPE_MAX11205A] },
+ { "max11205b", (kernel_ulong_t)&max11205_chip_info[TYPE_MAX11205B] },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, max11205_spi_ids);
+
+static const struct of_device_id max11205_dt_ids[] = {
+ {
+ .compatible = "maxim,max11205a",
+ .data = &max11205_chip_info[TYPE_MAX11205A],
+ },
+ {
+ .compatible = "maxim,max11205b",
+ .data = &max11205_chip_info[TYPE_MAX11205B],
+ },
+ { }
+};
+MODULE_DEVICE_TABLE(of, max11205_dt_ids);
+
+static struct spi_driver max11205_spi_driver = {
+ .driver = {
+ .name = "max11205",
+ .of_match_table = max11205_dt_ids,
+ },
+ .probe = max11205_probe,
+ .id_table = max11205_spi_ids,
+};
+module_spi_driver(max11205_spi_driver);
+
+MODULE_AUTHOR("Ramona Bolboaca <ramona.bolboaca@analog.com>");
+MODULE_DESCRIPTION("MAX11205 ADC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS(IIO_AD_SIGMA_DELTA);