path: root/drivers/iio/inkern.c

// SPDX-License-Identifier: GPL-2.0-only
/* The industrial I/O core in kernel channel mapping
 *
 * Copyright (c) 2011 Jonathan Cameron
 */
#include <linux/err.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/of.h>

#include <linux/iio/iio.h>
#include <linux/iio/iio-opaque.h>
#include "iio_core.h"
#include <linux/iio/machine.h>
#include <linux/iio/driver.h>
#include <linux/iio/consumer.h>

struct iio_map_internal {
	struct iio_dev *indio_dev;
	struct iio_map *map;
	struct list_head l;
};

static LIST_HEAD(iio_map_list);
static DEFINE_MUTEX(iio_map_list_lock);

static int iio_map_array_unregister_locked(struct iio_dev *indio_dev)
{
	int ret = -ENODEV;
	struct iio_map_internal *mapi, *next;

	list_for_each_entry_safe(mapi, next, &iio_map_list, l) {
		if (indio_dev == mapi->indio_dev) {
			list_del(&mapi->l);
			kfree(mapi);
			ret = 0;
		}
	}
	return ret;
}

int iio_map_array_register(struct iio_dev *indio_dev, struct iio_map *maps)
{
	int i = 0, ret = 0;
	struct iio_map_internal *mapi;

	if (maps == NULL)
		return 0;

	mutex_lock(&iio_map_list_lock);
	while (maps[i].consumer_dev_name != NULL) {
		mapi = kzalloc(sizeof(*mapi), GFP_KERNEL);
		if (mapi == NULL) {
			ret = -ENOMEM;
			goto error_ret;
		}
		mapi->map = &maps[i];
		mapi->indio_dev = indio_dev;
		list_add_tail(&mapi->l, &iio_map_list);
		i++;
	}
error_ret:
	if (ret)
		iio_map_array_unregister_locked(indio_dev);
	mutex_unlock(&iio_map_list_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_map_array_register);


/*
 * Remove all map entries associated with the given iio device
 */
int iio_map_array_unregister(struct iio_dev *indio_dev)
{
	int ret;

	mutex_lock(&iio_map_list_lock);
	ret = iio_map_array_unregister_locked(indio_dev);
	mutex_unlock(&iio_map_list_lock);

	return ret;
}
EXPORT_SYMBOL_GPL(iio_map_array_unregister);

static void iio_map_array_unregister_cb(void *indio_dev)
{
	iio_map_array_unregister(indio_dev);
}

int devm_iio_map_array_register(struct device *dev, struct iio_dev *indio_dev, struct iio_map *maps)
{
	int ret;

	ret = iio_map_array_register(indio_dev, maps);
	if (ret)
		return ret;

	return devm_add_action_or_reset(dev, iio_map_array_unregister_cb, indio_dev);
}
EXPORT_SYMBOL_GPL(devm_iio_map_array_register);

static const struct iio_chan_spec
*iio_chan_spec_from_name(const struct iio_dev *indio_dev, const char *name)
{
	int i;
	const struct iio_chan_spec *chan = NULL;

	for (i = 0; i < indio_dev->num_channels; i++)
		if (indio_dev->channels[i].datasheet_name &&
		    strcmp(name, indio_dev->channels[i].datasheet_name) == 0) {
			chan = &indio_dev->channels[i];
			break;
		}
	return chan;
}

#ifdef CONFIG_OF

static int iio_dev_node_match(struct device *dev, const void *data)
{
	return dev->of_node == data && dev->type == &iio_device_type;
}

/**
 * __of_iio_simple_xlate - translate iiospec to the IIO channel index
 * @indio_dev:	pointer to the iio_dev structure
 * @iiospec:	IIO specifier as found in the device tree
 *
 * This is simple translation function, suitable for the most 1:1 mapped
 * channels in IIO chips. This function performs only one sanity check:
 * whether IIO index is less than num_channels (that is specified in the
 * iio_dev).
 */
static int __of_iio_simple_xlate(struct iio_dev *indio_dev,
				const struct of_phandle_args *iiospec)
{
	if (!iiospec->args_count)
		return 0;

	if (iiospec->args[0] >= indio_dev->num_channels) {
		dev_err(&indio_dev->dev, "invalid channel index %u\n",
			iiospec->args[0]);
		return -EINVAL;
	}

	return iiospec->args[0];
}

static int __of_iio_channel_get(struct iio_channel *channel,
				struct device_node *np, int index)
{
	struct device *idev;
	struct iio_dev *indio_dev;
	int err;
	struct of_phandle_args iiospec;

	err = of_parse_phandle_with_args(np, "io-channels",
					 "#io-channel-cells",
					 index, &iiospec);
	if (err)
		return err;

	idev = bus_find_device(&iio_bus_type, NULL, iiospec.np,
			       iio_dev_node_match);
	of_node_put(iiospec.np);
	if (idev == NULL)
		return -EPROBE_DEFER;

	indio_dev = dev_to_iio_dev(idev);
	channel->indio_dev = indio_dev;
	if (indio_dev->info->of_xlate)
		index = indio_dev->info->of_xlate(indio_dev, &iiospec);
	else
		index = __of_iio_simple_xlate(indio_dev, &iiospec);
	if (index < 0)
		goto err_put;
	channel->channel = &indio_dev->channels[index];

	return 0;

err_put:
	iio_device_put(indio_dev);
	return index;
}

static struct iio_channel *of_iio_channel_get(struct device_node *np, int index)
{
	struct iio_channel *channel;
	int err;

	if (index < 0)
		return ERR_PTR(-EINVAL);

	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
	if (