drivers: ad400x: Add iio driver

Add initial IIO support for the ad400x driver.

Signed-off-by: Axel Haslam <ahaslam@baylibre.com>

drivers/adc/ad400x/iio_ad400x.c

@@ -0,0 +1,237 @@
+/***************************************************************************//**
+ *   @file   iio_ad400x.c
+ *   @brief  Implementation of AD400x IIO Driver.
+ *   @author Axel Haslam (ahaslam@baylibre.com)
+********************************************************************************
+ * Copyright 2024(c) Analog Devices, Inc.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - 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.
+ *  - 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.
+ *  - The use of this software may or may not infringe the patent rights
+ *    of one or more patent holders.  This license does not release you
+ *    from the requirement that you obtain separate licenses from these
+ *    patent holders to use this software.
+ *  - Use of the software either in source or binary form, must be run
+ *    on or directly connected to an Analog Devices Inc. component.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, 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 <stdio.h>
+#include <math.h>
+#include <string.h>
+
+#include "ad400x.h"
+#include "iio_ad400x.h"
+#include "iio.h"
+#include "no_os_util.h"
+#include "no_os_alloc.h"
+#include "no_os_error.h"
+
+/**
+ * @brief Read the debug register value
+ * @param device - Pointer to IIO device instance
+ * @param reg - Register address to read from
+ * @param val - Pointer to variable to read data into
+ * @return 0 in case of success, negative value otherwise
+ */
+static int32_t iio_ad400x_debug_reg_read(void *device, uint32_t reg,
+		uint32_t *val)
+{
+	struct ad400x_iio_dev *iio_dev = device;
+	struct ad400x_dev *dev = iio_dev->ad400x_dev;
+	int ret;
+	uint8_t val8;
+
+	ret = ad400x_spi_reg_read(dev, &val8);
+	if (ret)
+		return ret;
+
+	*val = val8;
+	return 0;
+}
+
+/**
+ * @brief Write the debug register value
+ * @param device - Pointer to IIO device instance
+ * @param reg - Register address to read from
+ * @param val - Pointer to variable to write data into
+ * @return 0 in case of success, negative value otherwise
+ */
+static int32_t iio_ad400x_debug_reg_write(void *device, uint32_t reg,
+		uint32_t val)
+{
+	struct ad400x_iio_dev *iio_dev = device;
+	struct ad400x_dev *dev = iio_dev->ad400x_dev;
+
+	return ad400x_spi_reg_write(dev, (uint8_t)val);
+}
+
+static int get_raw(void *device, char *buf, uint32_t len,
+		   const struct iio_ch_info *channel, intptr_t id)
+{
+	struct ad400x_iio_dev *iio_dev = device;
+	struct ad400x_dev *dev = iio_dev->ad400x_dev;
+	struct scan_type *scan_type;
+	uint32_t results;
+	int32_t results_signed;
+	int ret;
+
+	scan_type = iio_dev->iio_dev->channels[channel->ch_num].scan_type;
+
+	ret = ad400x_read_data(dev, &results, 1);
+	if (ret)
+		return ret;
+
+	if (scan_type->sign == 's') {
+		results_signed = no_os_sign_extend32(results, scan_type->realbits - 1);
+		return iio_format_value(buf, len, IIO_VAL_INT, 1, &results_signed);
+	}
+
+	return iio_format_value(buf, len, IIO_VAL_INT, 1, (int32_t *)&results);
+}
+
+static int get_scale(void *device, char *buf, uint32_t len,
+		     const struct iio_ch_info *channel, intptr_t id)
+{
+	struct ad400x_iio_dev *iio_dev = device;
+	struct scan_type *scan_type;
+	int32_t vals[2];
+
+	scan_type = iio_dev->iio_dev->channels[channel->ch_num].scan_type;
+	vals[0] = iio_dev->ref_voltage_mv;
+	if (scan_type->sign == 'u')
+		vals[1] = scan_type->realbits;
+	else
+		vals[1] = scan_type->realbits - 1;
+
+	return iio_format_value(buf, len, IIO_VAL_FRACTIONAL_LOG2, 2, vals);
+}
+
+/**
+ * @brief Read buffer data corresponding to AD400X IIO device
+ * @param iio_dev_data - Pointer to IIO device data structure
+ * @return 0 in case of success, negative error code otherwise
+ */
+static int32_t iio_ad400x_submit_buffer(struct iio_device_data *iio_dev_data)
+{
+	struct ad400x_iio_dev *iio_dev = iio_dev_data->dev;
+	struct ad400x_dev *dev = iio_dev->ad400x_dev;
+	struct iio_buffer *buffer = iio_dev_data->buffer;
+	void *buff;
+	int ret;
+
+	ret = iio_buffer_get_block(iio_dev_data->buffer, &buff);
+	if (ret)
+		return ret;
+
+	ret = ad400x_read_data(dev, buff, buffer->samples);
+	if (ret)
+		return ret;
+
+	return iio_buffer_block_done(buffer);
+}
+
+static struct iio_attribute ad400x_iio_ch_attributes[] = {
+	{ .name = "raw", .show = get_raw },
+	{ .name = "scale", .show = get_scale, },
+	END_ATTRIBUTES_ARRAY
+};
+
+static struct iio_channel ad400x_channel = {
+	.name = "voltage0",
+	.ch_type = IIO_VOLTAGE,
+	.ch_out = IIO_DIRECTION_INPUT,
+	.indexed = true,
+	.channel = 0,
+	.scan_index = 0,
+	.attributes = ad400x_iio_ch_attributes,
+};
+
+static struct iio_device ad400x_iio_device_template = {
+	.num_ch = 1,
+	.channels = &ad400x_channel,
+	.debug_reg_read = iio_ad400x_debug_reg_read,
+	.debug_reg_write= iio_ad400x_debug_reg_write,
+	.submit = iio_ad400x_submit_buffer,
+};
+
+/**
+ * @brief Initialize AD400X for IIO interfacing
+ * @param dev - The device structure.
+ * @param iio_init_param - IIO init parameter structure
+ * @return 0 on success, an error code otherwise
+ */
+int ad400x_iio_init(struct ad400x_iio_dev **dev,
+		    struct ad400x_iio_init_param *iio_init_param)
+{
+	struct ad400x_iio_dev *desc;
+	enum ad400x_supported_dev_ids dev_id;
+	int ret;
+
+	desc = no_os_calloc(1, sizeof(*desc));
+	if (!desc)
+		return -ENOMEM;
+
+	desc->iio_dev = &ad400x_iio_device_template;
+	desc->ref_voltage_mv = iio_init_param->ref_voltage_mv;
+
+	dev_id = iio_init_param->init_param->dev_id;
+
+	/* fill scan_type based on device id */
+	desc->scan_type.sign = ad400x_device_sign[dev_id];
+	desc->scan_type.realbits = ad400x_device_resol[dev_id];
+	desc->scan_type.storagebits = 32;
+	desc->scan_type.is_big_endian = false;
+	desc->scan_type.shift = 0;
+
+
+	desc->iio_dev->channels[0].scan_type = &desc->scan_type;
+
+	ret = ad400x_init(&desc->ad400x_dev, iio_init_param->init_param);
+	if (ret)
+		goto error_setup;
+
+	*dev = desc;
+
+	return 0;
+
+error_setup:
+	no_os_free(desc);
+	return ret;
+}
+
+/**
+ * @brief Release resources.
+ * @param iio_dev - iio device.
+ * @return 0 in case of success, error otherwise.
+ */
+int ad400x_iio_remove(struct ad400x_iio_dev *iio_dev)
+{
+	if (!iio_dev)
+		return -EINVAL;
+
+	ad400x_remove(iio_dev->ad400x_dev);
+
+	no_os_free(iio_dev);
+	return 0;
+}

drivers/adc/ad400x/iio_ad400x.h

@@ -0,0 +1,85 @@
+/***************************************************************************//**
+ *   @file   iio_ad400x.h
+ *   @brief  Header file for AD400X IIO interface
+ *   @author Axel Haslam (ahaslam@baylibre.com)
+********************************************************************************
+ * Copyright 2024(c) Analog Devices, Inc.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - 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.
+ *  - 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.
+ *  - The use of this software may or may not infringe the patent rights
+ *    of one or more patent holders.  This license does not release you
+ *    from the requirement that you obtain separate licenses from these
+ *    patent holders to use this software.
+ *  - Use of the software either in source or binary form, must be run
+ *    on or directly connected to an Analog Devices Inc. component.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, 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 _AD400X_IIO_H_
+#define _AD400X_IIO_H_
+
+/******************************************************************************/
+/***************************** Include Files **********************************/
+/******************************************************************************/
+#include <stdint.h>
+
+#include "iio.h"
+#include "iio_types.h"
+#include "ad400x.h"
+
+/******************************************************************************/
+/********************** Public/Extern Declarations ****************************/
+/******************************************************************************/
+/**
+ * @struct ad400x_iio_dev
+ * @brief AD400x IIO device structure
+ */
+struct ad400x_iio_dev {
+	/** AD400x driver handler */
+	struct ad400x_dev *ad400x_dev;
+	/** Generic IIO device handler */
+	struct iio_device *iio_dev;
+	/* Voltage reference */
+	uint32_t ref_voltage_mv;
+	/* scan type */
+	struct scan_type scan_type;
+};
+
+/**
+ * @struct ad400x_iio_init_param
+ * @brief AD400x IIO initialization structure
+ */
+struct ad400x_iio_init_param {
+	struct ad400x_init_param *init_param;
+	/* Voltage reference */
+	uint32_t ref_voltage_mv;
+};
+
+/** Allocate memory for AD400x IIO handler. */
+int ad400x_iio_init(struct ad400x_iio_dev **dev,
+		    struct ad400x_iio_init_param *iio_init_param);
+/** Free memory allocated by iio_ad400x_init(). */
+int ad400x_iio_remove(struct ad400x_iio_dev *dev);
+#endif /* __AD400X_IIO_H__ */