drivers/pinctrl/devicetree.c - arm/linux-arm-legacy - 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/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;
 		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) {
 		dev_err(p->dev, "failed to alloc struct pinctrl_dt_map\n");
 		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, true);
 }

 struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
 {
 	struct pinctrl_dev *pctldev;

 	pctldev = get_pinctrl_dev_from_of_node(np);
 	if (!pctldev)
 		return NULL;

 	return pctldev;
 }

 static int dt_to_map_one_config(struct pinctrl *p, const char *statename,
 				struct device_node *np_config)
 {
 	struct device_node *np_pctldev;
 	struct pinctrl_dev *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 %s, deferring probe\n",
 				np_config->full_name);
 			of_node_put(np_pctldev);
 			/* OK let's just assume this will appear later then */
 			return -EPROBE_DEFER;
 		}
 		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) {
 		dev_err(p->dev, "failed to alloc struct pinctrl_map\n");
 		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);
 }

 int pinctrl_dt_to_map(struct pinctrl *p)
 {
 	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) {
 		dev_dbg(p->dev, "no of_node; not parsing pinctrl DT\n");
 		return 0;
 	}

 	/* 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)
 			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, 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;
 }
	/*
	* 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/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;
	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) {
	dev_err(p->dev, "failed to alloc struct pinctrl_dt_map\n");
	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, true);
	}

	struct pinctrl_dev of_pinctrl_get(struct device_node np)
	{
	struct pinctrl_dev *pctldev;

	pctldev = get_pinctrl_dev_from_of_node(np);
	if (!pctldev)
	return NULL;

	return pctldev;
	}

	static int dt_to_map_one_config(struct pinctrl p, const char statename,
	struct device_node *np_config)
	{
	struct device_node *np_pctldev;
	struct pinctrl_dev *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 %s, deferring probe\n",
	np_config->full_name);
	of_node_put(np_pctldev);
	/* OK let's just assume this will appear later then */
	return -EPROBE_DEFER;
	}
	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) {
	dev_err(p->dev, "failed to alloc struct pinctrl_map\n");
	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);
	}

	int pinctrl_dt_to_map(struct pinctrl *p)
	{
	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) {
	dev_dbg(p->dev, "no of_node; not parsing pinctrl DT\n");
	return 0;
	}

	/* 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)
	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, 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;
	}