Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
83 lines
2.3 KiB
C
83 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Helpers for parsing common ADC information from a firmware node.
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*
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* Copyright (c) 2025 Matti Vaittinen <mazziesaccount@gmail.com>
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*/
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#include <linux/device.h>
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#include <linux/errno.h>
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#include <linux/export.h>
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#include <linux/module.h>
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#include <linux/property.h>
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#include <linux/types.h>
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#include <linux/iio/adc-helpers.h>
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#include <linux/iio/iio.h>
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/**
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* devm_iio_adc_device_alloc_chaninfo_se - allocate and fill iio_chan_spec for ADC
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*
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* Scan the device node for single-ended ADC channel information. Channel ID is
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* expected to be found from the "reg" property. Allocate and populate the
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* iio_chan_spec structure corresponding to channels that are found. The memory
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* for iio_chan_spec structure will be freed upon device detach.
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*
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* @dev: Pointer to the ADC device.
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* @template: Template iio_chan_spec from which the fields of all
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* found and allocated channels are initialized.
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* @max_chan_id: Maximum value of a channel ID. Use negative value if no
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* checking is required.
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* @cs: Location where pointer to allocated iio_chan_spec
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* should be stored.
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*
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* Return: Number of found channels on success. Negative value to indicate
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* failure. Specifically, -ENOENT if no channel nodes were found.
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*/
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int devm_iio_adc_device_alloc_chaninfo_se(struct device *dev,
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const struct iio_chan_spec *template,
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int max_chan_id,
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struct iio_chan_spec **cs)
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{
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struct iio_chan_spec *chan_array, *chan;
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int num_chan, ret;
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num_chan = iio_adc_device_num_channels(dev);
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if (num_chan < 0)
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return num_chan;
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if (!num_chan)
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return -ENOENT;
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chan_array = devm_kcalloc(dev, num_chan, sizeof(*chan_array),
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GFP_KERNEL);
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if (!chan_array)
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return -ENOMEM;
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chan = &chan_array[0];
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device_for_each_named_child_node_scoped(dev, child, "channel") {
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u32 ch;
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ret = fwnode_property_read_u32(child, "reg", &ch);
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if (ret)
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return ret;
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if (max_chan_id >= 0 && ch > max_chan_id)
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return -ERANGE;
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*chan = *template;
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chan->channel = ch;
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chan++;
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}
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*cs = chan_array;
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return num_chan;
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}
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EXPORT_SYMBOL_NS_GPL(devm_iio_adc_device_alloc_chaninfo_se, "IIO_DRIVER");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Matti Vaittinen <mazziesaccount@gmail.com>");
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MODULE_DESCRIPTION("IIO ADC fwnode parsing helpers");
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