@@ -6,6 +6,9 @@
menu "Analog to digital converters"
+config IIO_ADC_HELPER
+ tristate
+
config AB8500_GPADC
bool "ST-Ericsson AB8500 GPADC driver"
depends on AB8500_CORE && REGULATOR_AB8500
@@ -3,6 +3,8 @@
# Makefile for IIO ADC drivers
#
+obj-$(CONFIG_IIO_ADC_HELPER) += industrialio-adc.o
+
# When adding new entries keep the list in alphabetical order
obj-$(CONFIG_AB8500_GPADC) += ab8500-gpadc.o
obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
new file mode 100644
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Helpers for parsing common ADC information from a firmware node.
+ *
+ * Copyright (c) 2025 Matti Vaittinen <mazziesaccount@gmail.com>
+ */
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/types.h>
+
+#include <linux/iio/adc-helpers.h>
+#include <linux/iio/iio.h>
+
+/**
+ * devm_iio_adc_device_alloc_chaninfo_se - allocate and fill iio_chan_spec for ADC
+ *
+ * Scan the device node for single-ended ADC channel information. Channel ID is
+ * expected to be found from the "reg" property. Allocate and populate the
+ * iio_chan_spec structure corresponding to channels that are found. The memory
+ * for iio_chan_spec structure will be freed upon device detach.
+ *
+ * @dev: Pointer to the ADC device.
+ * @template: Template iio_chan_spec from which the fields of all
+ * found and allocated channels are initialized.
+ * @max_chan_id: Maximum value of a channel ID. Use negative value if no
+ * checking is required.
+ * @cs: Location where pointer to allocated iio_chan_spec
+ * should be stored.
+ *
+ * Return: Number of found channels on success. Negative value to indicate
+ * failure. Specifically, -ENOENT if no channel nodes were found.
+ */
+int devm_iio_adc_device_alloc_chaninfo_se(struct device *dev,
+ const struct iio_chan_spec *template,
+ int max_chan_id,
+ struct iio_chan_spec **cs)
+{
+ struct iio_chan_spec *chan_array, *chan;
+ int num_chan, ret;
+
+ num_chan = iio_adc_device_num_channels(dev);
+ if (num_chan < 0)
+ return num_chan;
+
+ if (!num_chan)
+ return -ENOENT;
+
+ chan_array = devm_kcalloc(dev, num_chan, sizeof(*chan_array),
+ GFP_KERNEL);
+ if (!chan_array)
+ return -ENOMEM;
+
+ chan = &chan_array[0];
+
+ device_for_each_named_child_node_scoped(dev, child, "channel") {
+ u32 ch;
+
+ ret = fwnode_property_read_u32(child, "reg", &ch);
+ if (ret)
+ return ret;
+
+ if (max_chan_id >= 0 && ch > max_chan_id)
+ return -ERANGE;
+
+ *chan = *template;
+ chan->channel = ch;
+ chan++;
+ }
+
+ *cs = chan_array;
+
+ return num_chan;
+}
+EXPORT_SYMBOL_NS_GPL(devm_iio_adc_device_alloc_chaninfo_se, "IIO_DRIVER");
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Matti Vaittinen <mazziesaccount@gmail.com>");
+MODULE_DESCRIPTION("IIO ADC fwnode parsing helpers");
new file mode 100644
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/*
+ * The industrial I/O ADC firmware property parsing helpers
+ *
+ * Copyright (c) 2025 Matti Vaittinen <mazziesaccount@gmail.com>
+ */
+
+#ifndef _INDUSTRIAL_IO_ADC_HELPERS_H_
+#define _INDUSTRIAL_IO_ADC_HELPERS_H_
+
+#include <linux/property.h>
+
+struct device;
+struct iio_chan_spec;
+
+static inline int iio_adc_device_num_channels(struct device *dev)
+{
+ return device_get_named_child_node_count(dev, "channel");
+}
+
+int devm_iio_adc_device_alloc_chaninfo_se(struct device *dev,
+ const struct iio_chan_spec *template,
+ int max_chan_id,
+ struct iio_chan_spec **cs);
+
+#endif /* _INDUSTRIAL_IO_ADC_HELPERS_H_ */