[deliverable/linux.git] / drivers / pinctrl / devicetree.c

/*
 * 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) {
		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);
}

static struct pinctrl_dev *find_pinctrl_by_of_node(struct device_node *np)
{
	struct pinctrl_dev *pctldev;

	list_for_each_entry(pctldev, &pinctrldev_list, node)
		if (pctldev->dev->of_node == np)
			return pctldev;

	return NULL;
}

struct pinctrl_dev *of_pinctrl_add_gpio_range(struct device_node *np,
		struct pinctrl_gpio_range *range)
{
	struct pinctrl_dev *pctldev;

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

	pinctrl_add_gpio_range(pctldev, range);
	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;
	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 = find_pinctrl_by_of_node(np_pctldev);
		if (pctldev)
			break;
	}
	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;
}
Commit	Line	Data
57291ce2 SW	1	/*
	2	* Device tree integration for the pin control subsystem
	3	*
	4	* Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms and conditions of the GNU General Public License,
	8	* version 2, as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	17	*/
	18
	19	#include <linux/device.h>
	20	#include <linux/of.h>
	21	#include <linux/pinctrl/pinctrl.h>
	22	#include <linux/slab.h>
	23
	24	#include "core.h"
	25	#include "devicetree.h"
	26
	27	/**
	28	* struct pinctrl_dt_map - mapping table chunk parsed from device tree
	29	* @node: list node for struct pinctrl's @dt_maps field
	30	* @pctldev: the pin controller that allocated this struct, and will free it
	31	* @maps: the mapping table entries
	32	*/
	33	struct pinctrl_dt_map {
	34	struct list_head node;
	35	struct pinctrl_dev *pctldev;
	36	struct pinctrl_map *map;
	37	unsigned num_maps;
	38	};
	39
	40	static void dt_free_map(struct pinctrl_dev *pctldev,
	41	struct pinctrl_map *map, unsigned num_maps)
	42	{
	43	if (pctldev) {
	44	struct pinctrl_ops *ops = pctldev->desc->pctlops;
	45	ops->dt_free_map(pctldev, map, num_maps);
	46	} else {
	47	/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
	48	kfree(map);
	49	}
	50	}
	51
	52	void pinctrl_dt_free_maps(struct pinctrl *p)
	53	{
	54	struct pinctrl_dt_map dt_map, n1;
	55
	56	list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
	57	pinctrl_unregister_map(dt_map->map);
	58	list_del(&dt_map->node);
	59	dt_free_map(dt_map->pctldev, dt_map->map,
	60	dt_map->num_maps);
	61	kfree(dt_map);
	62	}
	63
	64	of_node_put(p->dev->of_node);
65	}
66
67	static int dt_remember_or_free_map(struct pinctrl p, const char statename,
68	struct pinctrl_dev *pctldev,
69	struct pinctrl_map *map, unsigned num_maps)
70	{
71	int i;
72	struct pinctrl_dt_map *dt_map;
73
74	/* Initialize common mapping table entry fields */
75	for (i = 0; i < num_maps; i++) {
76	map[i].dev_name = dev_name(p->dev);
77	map[i].name = statename;
78	if (pctldev)
79	map[i].ctrl_dev_name = dev_name(pctldev->dev);
80	}
81
82	/* Remember the converted mapping table entries */
83	dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
84	if (!dt_map) {
85	dev_err(p->dev, "failed to alloc struct pinctrl_dt_map\n");
86	dt_free_map(pctldev, map, num_maps);
87	return -ENOMEM;
88	}
89
90	dt_map->pctldev = pctldev;
91	dt_map->map = map;
92	dt_map->num_maps = num_maps;
93	list_add_tail(&dt_map->node, &p->dt_maps);
94
95	return pinctrl_register_map(map, num_maps, false, true);
96	}
97
98	static struct pinctrl_dev find_pinctrl_by_of_node(struct device_node np)
99	{
100	struct pinctrl_dev *pctldev;
101
102	list_for_each_entry(pctldev, &pinctrldev_list, node)
103	if (pctldev->dev->of_node == np)
104	return pctldev;
105
106	return NULL;
107	}
108
f23f1516 SH	109	struct pinctrl_dev of_pinctrl_add_gpio_range(struct device_node np,
	110	struct pinctrl_gpio_range *range)
	111	{
	112	struct pinctrl_dev *pctldev;
	113
	114	pctldev = find_pinctrl_by_of_node(np);
	115	if (!pctldev)
	116	return NULL;
	117
	118	pinctrl_add_gpio_range(pctldev, range);
	119	return pctldev;
	120	}
	121
57291ce2 SW	122	static int dt_to_map_one_config(struct pinctrl p, const char statename,
	123	struct device_node *np_config)
	124	{
	125	struct device_node *np_pctldev;
	126	struct pinctrl_dev *pctldev;
	127	struct pinctrl_ops *ops;
	128	int ret;
	129	struct pinctrl_map *map;
	130	unsigned num_maps;
	131
	132	/* Find the pin controller containing np_config */
	133	np_pctldev = of_node_get(np_config);
	134	for (;;) {
	135	np_pctldev = of_get_next_parent(np_pctldev);
	136	if (!np_pctldev \|\| of_node_is_root(np_pctldev)) {
c05127c4	137	dev_info(p->dev, "could not find pctldev for node %s, deferring probe\n",
57291ce2 SW	138	np_config->full_name);
57291ce2 SW	139	of_node_put(np_pctldev);
c05127c4 LW	140	/* OK let's just assume this will appear later then */
c05127c4 LW	141	return -EPROBE_DEFER;
57291ce2 SW	142	}
	143	pctldev = find_pinctrl_by_of_node(np_pctldev);
	144	if (pctldev)
	145	break;
	146	}
	147	of_node_put(np_pctldev);
	148
	149	/*
	150	* Call pinctrl driver to parse device tree node, and
	151	* generate mapping table entries
	152	*/
	153	ops = pctldev->desc->pctlops;
	154	if (!ops->dt_node_to_map) {
	155	dev_err(p->dev, "pctldev %s doesn't support DT\n",
	156	dev_name(pctldev->dev));
	157	return -ENODEV;
	158	}
	159	ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
	160	if (ret < 0)
	161	return ret;
	162
	163	/* Stash the mapping table chunk away for later use */
	164	return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
	165	}
	166
	167	static int dt_remember_dummy_state(struct pinctrl p, const char statename)
	168	{
	169	struct pinctrl_map *map;
	170
	171	map = kzalloc(sizeof(*map), GFP_KERNEL);
	172	if (!map) {
	173	dev_err(p->dev, "failed to alloc struct pinctrl_map\n");
	174	return -ENOMEM;
	175	}
	176
	177	/* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
	178	map->type = PIN_MAP_TYPE_DUMMY_STATE;
	179
	180	return dt_remember_or_free_map(p, statename, NULL, map, 1);
	181	}
	182
	183	int pinctrl_dt_to_map(struct pinctrl *p)
	184	{
	185	struct device_node *np = p->dev->of_node;
	186	int state, ret;
	187	char *propname;
	188	struct property *prop;
	189	const char *statename;
	190	const __be32 *list;
	191	int size, config;
	192	phandle phandle;
	193	struct device_node *np_config;
	194
	195	/* CONFIG_OF enabled, p->dev not instantiated from DT */
	196	if (!np) {
	197	dev_dbg(p->dev, "no of_node; not parsing pinctrl DT\n");
	198	return 0;
	199	}
	200
	201	/* We may store pointers to property names within the node */
	202	of_node_get(np);
	203
	204	/* For each defined state ID */
	205	for (state = 0; ; state++) {
206	/* Retrieve the pinctrl-* property */
207	propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
208	prop = of_find_property(np, propname, &size);
209	kfree(propname);
210	if (!prop)
211	break;
212	list = prop->value;
213	size /= sizeof(*list);
214
215	/* Determine whether pinctrl-names property names the state */
216	ret = of_property_read_string_index(np, "pinctrl-names",
217	state, &statename);
218	/*
219	* If not, statename is just the integer state ID. But rather
220	* than dynamically allocate it and have to free it later,
221	* just point part way into the property name for the string.
222	*/
223	if (ret < 0) {
224	/* strlen("pinctrl-") == 8 */
225	statename = prop->name + 8;
226	}
227
228	/* For every referenced pin configuration node in it */
229	for (config = 0; config < size; config++) {
230	phandle = be32_to_cpup(list++);
231
232	/* Look up the pin configuration node */
233	np_config = of_find_node_by_phandle(phandle);
234	if (!np_config) {
235	dev_err(p->dev,
236	"prop %s index %i invalid phandle\n",
237	prop->name, config);
238	ret = -EINVAL;
239	goto err;
240	}
241
242	/* Parse the node */
243	ret = dt_to_map_one_config(p, statename, np_config);
244	of_node_put(np_config);
245	if (ret < 0)
246	goto err;
247	}
248
249	/* No entries in DT? Generate a dummy state table entry */
250	if (!size) {
251	ret = dt_remember_dummy_state(p, statename);
252	if (ret < 0)
253	goto err;
254	}
255	}
256
257	return 0;
258
259	err:
260	pinctrl_dt_free_maps(p);
261	return ret;
262	}