drivers/pinctrl/devicetree.c - linux-imx - Git at Google

 /*
  * Device tree integration for the pin control subsystem
  *
  * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * This program is distributed in the hope it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */

 #include <linux/device.h>
 #include <linux/of.h>
 #include <linux/of_gpio.h>
 #include <linux/pinctrl/pinctrl.h>
 #include <linux/slab.h>

 #include "core.h"
 #include "devicetree.h"

 /**
  * struct pinctrl_dt_map - mapping table chunk parsed from device tree
  * @node: list node for struct pinctrl's @dt_maps field
  * @pctldev: the pin controller that allocated this struct, and will free it
  * @maps: the mapping table entries
  */
 struct pinctrl_dt_map {
 	struct list_head node;
 	struct pinctrl_dev *pctldev;
 	struct pinctrl_map *map;
 	unsigned num_maps;
 };

 static void dt_free_map(struct pinctrl_dev *pctldev,
 		     struct pinctrl_map *map, unsigned num_maps)
 {
 	if (pctldev) {
 		const struct pinctrl_ops *ops = pctldev->desc->pctlops;
 		if (ops->dt_free_map)
 			ops->dt_free_map(pctldev, map, num_maps);
 	} else {
 		/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
 		kfree(map);
 	}
 }

 void pinctrl_dt_free_maps(struct pinctrl *p)
 {
 	struct pinctrl_dt_map *dt_map, *n1;

 	list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
 		pinctrl_unregister_map(dt_map->map);
 		list_del(&dt_map->node);
 		dt_free_map(dt_map->pctldev, dt_map->map,
 			    dt_map->num_maps);
 		kfree(dt_map);
 	}

 	of_node_put(p->dev->of_node);
 }

 static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
 				   struct pinctrl_dev *pctldev,
 				   struct pinctrl_map *map, unsigned num_maps)
 {
 	int i;
 	struct pinctrl_dt_map *dt_map;

 	/* Initialize common mapping table entry fields */
 	for (i = 0; i < num_maps; i++) {
 		map[i].dev_name = dev_name(p->dev);
 		map[i].name = statename;
 		if (pctldev)
 			map[i].ctrl_dev_name = dev_name(pctldev->dev);
 	}

 	/* Remember the converted mapping table entries */
 	dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
 	if (!dt_map) {
 		dt_free_map(pctldev, map, num_maps);
 		return -ENOMEM;
 	}

 	dt_map->pctldev = pctldev;
 	dt_map->map = map;
 	dt_map->num_maps = num_maps;
 	list_add_tail(&dt_map->node, &p->dt_maps);

 	return pinctrl_register_map(map, num_maps, false);
 }

 struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
 {
 	return get_pinctrl_dev_from_of_node(np);
 }

 static int dt_to_map_one_config(struct pinctrl *p,
 				struct pinctrl_dev *hog_pctldev,
 				const char *statename,
 				struct device_node *np_config)
 {
 	struct pinctrl_dev *pctldev = NULL;
 	struct device_node *np_pctldev;
 	const struct pinctrl_ops *ops;
 	int ret;
 	struct pinctrl_map *map;
 	unsigned num_maps;

 	/* Find the pin controller containing np_config */
 	np_pctldev = of_node_get(np_config);
 	for (;;) {
 		np_pctldev = of_get_next_parent(np_pctldev);
 		if (!np_pctldev || of_node_is_root(np_pctldev)) {
 			dev_info(p->dev, "could not find pctldev for node %pOF, deferring probe\n",
 				np_config);
 			of_node_put(np_pctldev);
 			/* OK let's just assume this will appear later then */
 			return -EPROBE_DEFER;
 		}
 		/* If we're creating a hog we can use the passed pctldev */
 		if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
 			pctldev = hog_pctldev;
 			break;
 		}
 		pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
 		if (pctldev)
 			break;
 		/* Do not defer probing of hogs (circular loop) */
 		if (np_pctldev == p->dev->of_node) {
 			of_node_put(np_pctldev);
 			return -ENODEV;
 		}
 	}
 	of_node_put(np_pctldev);

 	/*
 	 * Call pinctrl driver to parse device tree node, and
 	 * generate mapping table entries
 	 */
 	ops = pctldev->desc->pctlops;
 	if (!ops->dt_node_to_map) {
 		dev_err(p->dev, "pctldev %s doesn't support DT\n",
 			dev_name(pctldev->dev));
 		return -ENODEV;
 	}
 	ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
 	if (ret < 0)
 		return ret;

 	/* Stash the mapping table chunk away for later use */
 	return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
 }

 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
 {
 	struct pinctrl_map *map;

 	map = kzalloc(sizeof(*map), GFP_KERNEL);
 	if (!map)
 		return -ENOMEM;

 	/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
 	map->type = PIN_MAP_TYPE_DUMMY_STATE;

 	return dt_remember_or_free_map(p, statename, NULL, map, 1);
 }

 bool pinctrl_dt_has_hogs(struct pinctrl_dev *pctldev)
 {
 	struct device_node *np;
 	struct property *prop;
 	int size;

 	np = pctldev->dev->of_node;
 	if (!np)
 		return false;

 	prop = of_find_property(np, "pinctrl-0", &size);

 	return prop ? true : false;
 }

 static int dt_gpio_assert_pinctrl(struct pinctrl *p)
 {
 	struct device_node *np = p->dev->of_node;
 	enum of_gpio_flags flags;
 	int gpio;
 	int index = 0;
 	int ret;

 	if (!of_find_property(np, "pinctrl-assert-gpios", NULL))
 		return 0; /* Missing the property, so nothing to be done */

 	for (;; index++) {
 		gpio = of_get_named_gpio_flags(np, "pinctrl-assert-gpios",
 					       index, &flags);
 		if (gpio < 0) {
 			if (gpio == -EPROBE_DEFER)
 				return gpio;
 			break; /* End of the phandle list */
 		}

 		if (!gpio_is_valid(gpio))
 			return -EINVAL;

 		ret = devm_gpio_request_one(p->dev, gpio, GPIOF_OUT_INIT_LOW,
 					    NULL);
 		if (ret < 0)
 			return ret;

 		if (flags & OF_GPIO_ACTIVE_LOW)
 			continue;

 		if (gpio_cansleep(gpio))
 			gpio_set_value_cansleep(gpio, 1);
 		else
 			gpio_set_value(gpio, 1);
 	}

 	return 0;
 }

 int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
 {
 	struct device_node *np = p->dev->of_node;
 	int state, ret;
 	char *propname;
 	struct property *prop;
 	const char *statename;
 	const __be32 *list;
 	int size, config;
 	phandle phandle;
 	struct device_node *np_config;

 	/* CONFIG_OF enabled, p->dev not instantiated from DT */
 	if (!np) {
 		if (of_have_populated_dt())
 			dev_dbg(p->dev,
 				"no of_node; not parsing pinctrl DT\n");
 		return 0;
 	}

 	ret = dt_gpio_assert_pinctrl(p);
 	if (ret) {
 		dev_dbg(p->dev, "failed to assert pinctrl setting: %d\n", ret);
 		return ret;
 	}

 	/* We may store pointers to property names within the node */
 	of_node_get(np);

 	/* For each defined state ID */
 	for (state = 0; ; state++) {
 		/* Retrieve the pinctrl-* property */
 		propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
 		prop = of_find_property(np, propname, &size);
 		kfree(propname);
 		if (!prop) {
 			if (state == 0) {
 				of_node_put(np);
 				return -ENODEV;
 			}
 			break;
 		}
 		list = prop->value;
 		size /= sizeof(*list);

 		/* Determine whether pinctrl-names property names the state */
 		ret = of_property_read_string_index(np, "pinctrl-names",
 						    state, &statename);
 		/*
 		 * If not, statename is just the integer state ID. But rather
 		 * than dynamically allocate it and have to free it later,
 		 * just point part way into the property name for the string.
 		 */
 		if (ret < 0) {
 			/* strlen("pinctrl-") == 8 */
 			statename = prop->name + 8;
 		}

 		/* For every referenced pin configuration node in it */
 		for (config = 0; config < size; config++) {
 			phandle = be32_to_cpup(list++);

 			/* Look up the pin configuration node */
 			np_config = of_find_node_by_phandle(phandle);
 			if (!np_config) {
 				dev_err(p->dev,
 					"prop %s index %i invalid phandle\n",
 					prop->name, config);
 				ret = -EINVAL;
 				goto err;
 			}

 			/* Parse the node */
 			ret = dt_to_map_one_config(p, pctldev, statename,
 						   np_config);
 			of_node_put(np_config);
 			if (ret < 0)
 				goto err;
 		}

 		/* No entries in DT? Generate a dummy state table entry */
 		if (!size) {
 			ret = dt_remember_dummy_state(p, statename);
 			if (ret < 0)
 				goto err;
 		}
 	}

 	return 0;

 err:
 	pinctrl_dt_free_maps(p);
 	return ret;
 }

 /*
  * For pinctrl binding, typically #pinctrl-cells is for the pin controller
  * device, so either parent or grandparent. See pinctrl-bindings.txt.
  */
 static int pinctrl_find_cells_size(const struct device_node *np)
 {
 	const char *cells_name = "#pinctrl-cells";
 	int cells_size, error;

 	error = of_property_read_u32(np->parent, cells_name, &cells_size);
 	if (error) {
 		error = of_property_read_u32(np->parent->parent,
 					     cells_name, &cells_size);
 		if (error)
 			return -ENOENT;
 	}

 	return cells_size;
 }

 /**
  * pinctrl_get_list_and_count - Gets the list and it's cell size and number
  * @np: pointer to device node with the property
  * @list_name: property that contains the list
  * @list: pointer for the list found
  * @cells_size: pointer for the cell size found
  * @nr_elements: pointer for the number of elements found
  *
  * Typically np is a single pinctrl entry containing the list.
  */
 static int pinctrl_get_list_and_count(const struct device_node *np,
 				      const char *list_name,
 				      const __be32 **list,
 				      int *cells_size,
 				      int *nr_elements)
 {
 	int size;

 	*cells_size = 0;
 	*nr_elements = 0;

 	*list = of_get_property(np, list_name, &size);
 	if (!*list)
 		return -ENOENT;

 	*cells_size = pinctrl_find_cells_size(np);
 	if (*cells_size < 0)
 		return -ENOENT;

 	/* First element is always the index within the pinctrl device */
 	*nr_elements = (size / sizeof(**list)) / (*cells_size + 1);

 	return 0;
 }

 /**
  * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
  * @np: pointer to device node with the property
  * @list_name: property that contains the list
  *
  * Counts the number of elements in a pinctrl array consisting of an index
  * within the controller and a number of u32 entries specified for each
  * entry. Note that device_node is always for the parent pin controller device.
  */
 int pinctrl_count_index_with_args(const struct device_node *np,
 				  const char *list_name)
 {
 	const __be32 *list;
 	int size, nr_cells, error;

 	error = pinctrl_get_list_and_count(np, list_name, &list,
 					   &nr_cells, &size);
 	if (error)
 		return error;

 	return size;
 }
 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);

 /**
  * pinctrl_copy_args - Populates of_phandle_args based on index
  * @np: pointer to device node with the property
  * @list: pointer to a list with the elements
  * @index: entry within the list of elements
  * @nr_cells: number of cells in the list
  * @nr_elem: number of elements for each entry in the list
  * @out_args: returned values
  *
  * Populates the of_phandle_args based on the index in the list.
  */
 static int pinctrl_copy_args(const struct device_node *np,
 			     const __be32 *list,
 			     int index, int nr_cells, int nr_elem,
 			     struct of_phandle_args *out_args)
 {
 	int i;

 	memset(out_args, 0, sizeof(*out_args));
 	out_args->np = (struct device_node *)np;
 	out_args->args_count = nr_cells + 1;

 	if (index >= nr_elem)
 		return -EINVAL;

 	list += index * (nr_cells + 1);

 	for (i = 0; i < nr_cells + 1; i++)
 		out_args->args[i] = be32_to_cpup(list++);

 	return 0;
 }

 /**
  * pinctrl_parse_index_with_args - Find a node pointed by index in a list
  * @np: pointer to device node with the property
  * @list_name: property that contains the list
  * @index: index within the list
  * @out_arts: entries in the list pointed by index
  *
  * Finds the selected element in a pinctrl array consisting of an index
  * within the controller and a number of u32 entries specified for each
  * entry. Note that device_node is always for the parent pin controller device.
  */
 int pinctrl_parse_index_with_args(const struct device_node *np,
 				  const char *list_name, int index,
 				  struct of_phandle_args *out_args)
 {
 	const __be32 *list;
 	int nr_elem, nr_cells, error;

 	error = pinctrl_get_list_and_count(np, list_name, &list,
 					   &nr_cells, &nr_elem);
 	if (error || !nr_cells)
 		return error;

 	error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
 				  out_args);
 	if (error)
 		return error;

 	return 0;
 }
 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);
	/*
	* Device tree integration for the pin control subsystem
	*
	* Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* This program is distributed in the hope it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include <linux/device.h>
	#include <linux/of.h>
	#include <linux/of_gpio.h>
	#include <linux/pinctrl/pinctrl.h>
	#include <linux/slab.h>

	#include "core.h"
	#include "devicetree.h"

	/**
	* struct pinctrl_dt_map - mapping table chunk parsed from device tree
	* @node: list node for struct pinctrl's @dt_maps field
	* @pctldev: the pin controller that allocated this struct, and will free it
	* @maps: the mapping table entries
	*/
	struct pinctrl_dt_map {
	struct list_head node;
	struct pinctrl_dev *pctldev;
	struct pinctrl_map *map;
	unsigned num_maps;
	};

	static void dt_free_map(struct pinctrl_dev *pctldev,
	struct pinctrl_map *map, unsigned num_maps)
	{
	if (pctldev) {
	const struct pinctrl_ops *ops = pctldev->desc->pctlops;
	if (ops->dt_free_map)
	ops->dt_free_map(pctldev, map, num_maps);
	} else {
	/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
	kfree(map);
	}
	}

	void pinctrl_dt_free_maps(struct pinctrl *p)
	{
	struct pinctrl_dt_map dt_map, n1;

	list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
	pinctrl_unregister_map(dt_map->map);
	list_del(&dt_map->node);
	dt_free_map(dt_map->pctldev, dt_map->map,
	dt_map->num_maps);
	kfree(dt_map);
	}

	of_node_put(p->dev->of_node);
	}

	static int dt_remember_or_free_map(struct pinctrl p, const char statename,
	struct pinctrl_dev *pctldev,
	struct pinctrl_map *map, unsigned num_maps)
	{
	int i;
	struct pinctrl_dt_map *dt_map;

	/* Initialize common mapping table entry fields */
	for (i = 0; i < num_maps; i++) {
	map[i].dev_name = dev_name(p->dev);
	map[i].name = statename;
	if (pctldev)
	map[i].ctrl_dev_name = dev_name(pctldev->dev);
	}

	/* Remember the converted mapping table entries */
	dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
	if (!dt_map) {
	dt_free_map(pctldev, map, num_maps);
	return -ENOMEM;
	}

	dt_map->pctldev = pctldev;
	dt_map->map = map;
	dt_map->num_maps = num_maps;
	list_add_tail(&dt_map->node, &p->dt_maps);

	return pinctrl_register_map(map, num_maps, false);
	}

	struct pinctrl_dev of_pinctrl_get(struct device_node np)
	{
	return get_pinctrl_dev_from_of_node(np);
	}

	static int dt_to_map_one_config(struct pinctrl *p,
	struct pinctrl_dev *hog_pctldev,
	const char *statename,
	struct device_node *np_config)
	{
	struct pinctrl_dev *pctldev = NULL;
	struct device_node *np_pctldev;
	const struct pinctrl_ops *ops;
	int ret;
	struct pinctrl_map *map;
	unsigned num_maps;

	/* Find the pin controller containing np_config */
	np_pctldev = of_node_get(np_config);
	for (;;) {
	np_pctldev = of_get_next_parent(np_pctldev);
	if (!np_pctldev \|\| of_node_is_root(np_pctldev)) {
	dev_info(p->dev, "could not find pctldev for node %pOF, deferring probe\n",
	np_config);
	of_node_put(np_pctldev);
	/* OK let's just assume this will appear later then */
	return -EPROBE_DEFER;
	}
	/* If we're creating a hog we can use the passed pctldev */
	if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
	pctldev = hog_pctldev;
	break;
	}
	pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
	if (pctldev)
	break;
	/* Do not defer probing of hogs (circular loop) */
	if (np_pctldev == p->dev->of_node) {
	of_node_put(np_pctldev);
	return -ENODEV;
	}
	}
	of_node_put(np_pctldev);

	/*
	* Call pinctrl driver to parse device tree node, and
	* generate mapping table entries
	*/
	ops = pctldev->desc->pctlops;
	if (!ops->dt_node_to_map) {
	dev_err(p->dev, "pctldev %s doesn't support DT\n",
	dev_name(pctldev->dev));
	return -ENODEV;
	}
	ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
	if (ret < 0)
	return ret;

	/* Stash the mapping table chunk away for later use */
	return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
	}

	static int dt_remember_dummy_state(struct pinctrl p, const char statename)
	{
	struct pinctrl_map *map;

	map = kzalloc(sizeof(*map), GFP_KERNEL);
	if (!map)
	return -ENOMEM;

	/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
	map->type = PIN_MAP_TYPE_DUMMY_STATE;

	return dt_remember_or_free_map(p, statename, NULL, map, 1);
	}

	bool pinctrl_dt_has_hogs(struct pinctrl_dev *pctldev)
	{
	struct device_node *np;
	struct property *prop;
	int size;

	np = pctldev->dev->of_node;
	if (!np)
	return false;

	prop = of_find_property(np, "pinctrl-0", &size);

	return prop ? true : false;
	}

	static int dt_gpio_assert_pinctrl(struct pinctrl *p)
	{
	struct device_node *np = p->dev->of_node;
	enum of_gpio_flags flags;
	int gpio;
	int index = 0;
	int ret;

	if (!of_find_property(np, "pinctrl-assert-gpios", NULL))
	return 0; /* Missing the property, so nothing to be done */

	for (;; index++) {
	gpio = of_get_named_gpio_flags(np, "pinctrl-assert-gpios",
	index, &flags);
	if (gpio < 0) {
	if (gpio == -EPROBE_DEFER)
	return gpio;
	break; /* End of the phandle list */
	}

	if (!gpio_is_valid(gpio))
	return -EINVAL;

	ret = devm_gpio_request_one(p->dev, gpio, GPIOF_OUT_INIT_LOW,
	NULL);
	if (ret < 0)
	return ret;

	if (flags & OF_GPIO_ACTIVE_LOW)
	continue;

	if (gpio_cansleep(gpio))
	gpio_set_value_cansleep(gpio, 1);
	else
	gpio_set_value(gpio, 1);
	}

	return 0;
	}

	int pinctrl_dt_to_map(struct pinctrl p, struct pinctrl_dev pctldev)
	{
	struct device_node *np = p->dev->of_node;
	int state, ret;
	char *propname;
	struct property *prop;
	const char *statename;
	const __be32 *list;
	int size, config;
	phandle phandle;
	struct device_node *np_config;

	/* CONFIG_OF enabled, p->dev not instantiated from DT */
	if (!np) {
	if (of_have_populated_dt())
	dev_dbg(p->dev,
	"no of_node; not parsing pinctrl DT\n");
	return 0;
	}

	ret = dt_gpio_assert_pinctrl(p);
	if (ret) {
	dev_dbg(p->dev, "failed to assert pinctrl setting: %d\n", ret);
	return ret;
	}

	/* We may store pointers to property names within the node */
	of_node_get(np);

	/* For each defined state ID */
	for (state = 0; ; state++) {
	/* Retrieve the pinctrl-* property */
	propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
	prop = of_find_property(np, propname, &size);
	kfree(propname);
	if (!prop) {
	if (state == 0) {
	of_node_put(np);
	return -ENODEV;
	}
	break;
	}
	list = prop->value;
	size /= sizeof(*list);

	/* Determine whether pinctrl-names property names the state */
	ret = of_property_read_string_index(np, "pinctrl-names",
	state, &statename);
	/*
	* If not, statename is just the integer state ID. But rather
	* than dynamically allocate it and have to free it later,
	* just point part way into the property name for the string.
	*/
	if (ret < 0) {
	/* strlen("pinctrl-") == 8 */
	statename = prop->name + 8;
	}

	/* For every referenced pin configuration node in it */
	for (config = 0; config < size; config++) {
	phandle = be32_to_cpup(list++);

	/* Look up the pin configuration node */
	np_config = of_find_node_by_phandle(phandle);
	if (!np_config) {
	dev_err(p->dev,
	"prop %s index %i invalid phandle\n",
	prop->name, config);
	ret = -EINVAL;
	goto err;
	}

	/* Parse the node */
	ret = dt_to_map_one_config(p, pctldev, statename,
	np_config);
	of_node_put(np_config);
	if (ret < 0)
	goto err;
	}

	/* No entries in DT? Generate a dummy state table entry */
	if (!size) {
	ret = dt_remember_dummy_state(p, statename);
	if (ret < 0)
	goto err;
	}
	}

	return 0;

	err:
	pinctrl_dt_free_maps(p);
	return ret;
	}

	/*
	* For pinctrl binding, typically #pinctrl-cells is for the pin controller
	* device, so either parent or grandparent. See pinctrl-bindings.txt.
	*/
	static int pinctrl_find_cells_size(const struct device_node *np)
	{
	const char *cells_name = "#pinctrl-cells";
	int cells_size, error;

	error = of_property_read_u32(np->parent, cells_name, &cells_size);
	if (error) {
	error = of_property_read_u32(np->parent->parent,
	cells_name, &cells_size);
	if (error)
	return -ENOENT;
	}

	return cells_size;
	}

	/**
	* pinctrl_get_list_and_count - Gets the list and it's cell size and number
	* @np: pointer to device node with the property
	* @list_name: property that contains the list
	* @list: pointer for the list found
	* @cells_size: pointer for the cell size found
	* @nr_elements: pointer for the number of elements found
	*
	* Typically np is a single pinctrl entry containing the list.
	*/
	static int pinctrl_get_list_and_count(const struct device_node *np,
	const char *list_name,
	const __be32 **list,
	int *cells_size,
	int *nr_elements)
	{
	int size;

	*cells_size = 0;
	*nr_elements = 0;

	*list = of_get_property(np, list_name, &size);
	if (!*list)
	return -ENOENT;

	*cells_size = pinctrl_find_cells_size(np);
	if (*cells_size < 0)
	return -ENOENT;

	/* First element is always the index within the pinctrl device */
	nr_elements = (size / sizeof(list)) / (cells_size + 1);

	return 0;
	}

	/**
	* pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
	* @np: pointer to device node with the property
	* @list_name: property that contains the list
	*
	* Counts the number of elements in a pinctrl array consisting of an index
	* within the controller and a number of u32 entries specified for each
	* entry. Note that device_node is always for the parent pin controller device.
	*/
	int pinctrl_count_index_with_args(const struct device_node *np,
	const char *list_name)
	{
	const __be32 *list;
	int size, nr_cells, error;

	error = pinctrl_get_list_and_count(np, list_name, &list,
	&nr_cells, &size);
	if (error)
	return error;

	return size;
	}
	EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);

	/**
	* pinctrl_copy_args - Populates of_phandle_args based on index
	* @np: pointer to device node with the property
	* @list: pointer to a list with the elements
	* @index: entry within the list of elements
	* @nr_cells: number of cells in the list
	* @nr_elem: number of elements for each entry in the list
	* @out_args: returned values
	*
	* Populates the of_phandle_args based on the index in the list.
	*/
	static int pinctrl_copy_args(const struct device_node *np,
	const __be32 *list,
	int index, int nr_cells, int nr_elem,
	struct of_phandle_args *out_args)
	{
	int i;

	memset(out_args, 0, sizeof(*out_args));
	out_args->np = (struct device_node *)np;
	out_args->args_count = nr_cells + 1;

	if (index >= nr_elem)
	return -EINVAL;

	list += index * (nr_cells + 1);

	for (i = 0; i < nr_cells + 1; i++)
	out_args->args[i] = be32_to_cpup(list++);

	return 0;
	}

	/**
	* pinctrl_parse_index_with_args - Find a node pointed by index in a list
	* @np: pointer to device node with the property
	* @list_name: property that contains the list
	* @index: index within the list
	* @out_arts: entries in the list pointed by index
	*
	* Finds the selected element in a pinctrl array consisting of an index
	* within the controller and a number of u32 entries specified for each
	* entry. Note that device_node is always for the parent pin controller device.
	*/
	int pinctrl_parse_index_with_args(const struct device_node *np,
	const char *list_name, int index,
	struct of_phandle_args *out_args)
	{
	const __be32 *list;
	int nr_elem, nr_cells, error;

	error = pinctrl_get_list_and_count(np, list_name, &list,
	&nr_cells, &nr_elem);
	if (error \|\| !nr_cells)
	return error;

	error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
	out_args);
	if (error)
	return error;

	return 0;
	}
	EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);