drivers:adc:ltc2378: Add support for LTC2378-20

drivers/adc/ltc2378/iio_ltc2378.c

@@ -0,0 +1,195 @@
+/***************************************************************************//**
+ *   @file   iio_ltc2378.c
+ *   @brief  Implementation of iio_ltc2378.c.
+ *   @author Cherrence Sarip ([email protected])
+********************************************************************************
+ * Copyright 2025(c) Analog Devices, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of Analog Devices, Inc. nor the names of its
+ *    contributors may be used to endorse or promote products derived from this
+ *    software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES, INC. “AS IS” AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL ANALOG DEVICES, INC. BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
+ * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*******************************************************************************/
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "no_os_alloc.h"
+#include "no_os_error.h"
+#include "no_os_units.h"
+#include "no_os_util.h"
+#include "iio.h"
+#include "ltc2378.h"
+#include "iio_ltc2378.h"
+
+enum ltc2378_iio_attr {
+	LTC2378_IIO_RAW,
+	LTC2378_IIO_SCALE,
+	LTC2378_IIO_PROCESSED,
+};
+
+/**
+ * @brief Read from ADC and provide IIO data
+ * @param dev - The iio device structure.
+ * @param buf - Buffer to be filled with requested attr val.
+ * @param len - Length of the received command buffer in bytes.
+ * @param channel - Command channel info.
+ * @param priv - Command attribute id.
+ * @return 0 in case of success, negative error code otherwise.
+ */
+static int ltc2378_iio_read(void *dev, char *buf, uint32_t len,
+			    const struct iio_ch_info *channel, intptr_t priv)
+{
+	struct ltc2378_iio_desc *iio_ltc2378 = dev;
+	struct ltc2378_dev *ltc2378 = iio_ltc2378->ltc2378_dev;
+	int ret;
+	int64_t vals[2];
+	uint32_t raw_data;
+	int32_t voltage_uv;
+
+	if (!dev || !iio_ltc2378->ltc2378_dev)
+		return -EINVAL;
+
+	switch (priv) {
+	case LTC2378_IIO_RAW:
+		ret = ltc2378_read_raw(ltc2378, &raw_data);
+		if (ret)
+			return ret;
+
+		vals[0] = raw_data;
+		vals[1] = 0;
+		return iio_format_value(buf, len, IIO_VAL_INT, 1, vals);
+
+	case LTC2378_IIO_SCALE:
+		vals[0] = ltc2378->vref_uv;
+		if (ltc2378->input_mode == LTC2378_UNIPOLAR) {
+			vals[1] = LTC2378_IIO_SCALE_UNIPOLAR_SHIFT;
+		} else {
+			vals[1] = LTC2378_IIO_SCALE_BIPOLAR_SHIFT;
+		}
+		return iio_format_value(buf, len, IIO_VAL_FRACTIONAL_LOG2, 2, vals);
+
+	case LTC2378_IIO_PROCESSED:
+		ret = ltc2378_read_raw(ltc2378, &raw_data);
+		if (ret)
+			return ret;
+
+		ret = ltc2378_raw_to_uv(ltc2378, raw_data, &voltage_uv);
+		if (ret)
+			return ret;
+
+		vals[0] = voltage_uv;
+		vals[1] = 0;
+		return iio_format_value(buf, len, IIO_VAL_INT, 1, vals);
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static struct iio_attribute ltc2378_iio_attrs[] = {
+	{
+		.name = "raw",
+		.show = ltc2378_iio_read,
+		.store = NULL,
+		.priv = LTC2378_IIO_RAW,
+	},
+	{
+		.name = "scale",
+		.show = ltc2378_iio_read,
+		.store = NULL,
+		.priv = LTC2378_IIO_SCALE,
+	},
+	{
+		.name = "processed",
+		.show = ltc2378_iio_read,
+		.store = NULL,
+		.priv = LTC2378_IIO_PROCESSED,
+	},
+	END_ATTRIBUTES_ARRAY
+};
+
+static struct iio_channel ltc2378_iio_channels[] = {
+	{
+		.name = "voltage0",
+		.attributes = ltc2378_iio_attrs,
+		.ch_type = IIO_VOLTAGE,
+		.indexed = true,
+	}
+};
+
+static struct iio_device ltc2378_iio_dev = {
+	.channels = ltc2378_iio_channels,
+	.num_ch = NO_OS_ARRAY_SIZE(ltc2378_iio_channels),
+	.debug_reg_read = NULL,
+	.debug_reg_write = NULL,
+};
+
+/**
+ * @brief Initialize the IIO LTC2378 driver
+ * @param iio_desc - IIO device descriptor.
+ * @param init_param - Init parameter structure.
+ * @return 0 in case of success, negative error code otherwise.
+ */
+int ltc2378_iio_init(struct ltc2378_iio_desc **iio_desc,
+		     struct ltc2378_iio_desc_init_param *init_param)
+{
+	struct ltc2378_iio_desc *descriptor;
+	int ret;
+
+	if (!iio_desc || !init_param || !init_param->ltc2378_init_param)
+		return -EINVAL;
+
+	descriptor = no_os_calloc(1, sizeof(*descriptor));
+	if (!descriptor)
+		return -ENOMEM;
+
+	ret = ltc2378_init(&descriptor->ltc2378_dev, init_param->ltc2378_init_param);
+	if (ret)
+		goto error_free_desc;
+
+	descriptor->iio_dev = &ltc2378_iio_dev;
+
+	*iio_desc = descriptor;
+
+	return 0;
+
+error_free_desc:
+	no_os_free(descriptor);
+	return ret;
+}
+
+/**
+ * @brief Free the resources allocated by ltc2378_iio_init()
+ * @param iio_desc - IIO device descriptor.
+ * @return 0 in case of success, negative error code otherwise.
+ */
+int ltc2378_iio_remove(struct ltc2378_iio_desc *iio_desc)
+{
+	if (!iio_desc)
+		return -EINVAL;
+
+	ltc2378_remove(iio_desc->ltc2378_dev);
+	no_os_free(iio_desc);
+
+	return 0;
+}

drivers/adc/ltc2378/iio_ltc2378.h

@@ -0,0 +1,56 @@
+/***************************************************************************//**
+ *   @file   iio_ltc2378.h
+*   @brief  Header file of the LTC2378 IIO Driver
+ *   @author Cherrence Sarip ([email protected])
+********************************************************************************
+ * Copyright 2025(c) Analog Devices, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of Analog Devices, Inc. nor the names of its
+ *    contributors may be used to endorse or promote products derived from this
+ *    software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES, INC. “AS IS” AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+ * EVENT SHALL ANALOG DEVICES, INC. BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
+ * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*******************************************************************************/
+
+#ifndef IIO_LTC2378_H
+#define IIO_LTC2378_H
+
+#include <stdbool.h>
+#include "ltc2378.h"
+
+struct ltc2378_iio_desc {
+	struct ltc2378_dev *ltc2378_dev;
+	struct iio_device *iio_dev;
+};
+
+struct ltc2378_iio_desc_init_param {
+	struct ltc2378_init_param *ltc2378_init_param;
+};
+
+/* Initialize the LTC2378 IIO descriptor */
+int ltc2378_iio_init(struct ltc2378_iio_desc **,
+		     struct ltc2378_iio_desc_init_param *);
+
+/* Free resources allocated by the IIO initialization function */
+int ltc2378_iio_remove(struct ltc2378_iio_desc *);
+
+#endif /* IIO_LTC2378_H */