2 * Device tree integration for the pin control subsystem
4 * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
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.
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
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/>.
19 #include <linux/device.h>
21 #include <linux/pinctrl/pinctrl.h>
22 #include <linux/slab.h>
25 #include "devicetree.h"
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
33 struct pinctrl_dt_map {
34 struct list_head node;
35 struct pinctrl_dev *pctldev;
36 struct pinctrl_map *map;
40 static void dt_free_map(struct pinctrl_dev *pctldev,
41 struct pinctrl_map *map, unsigned num_maps)
44 const struct pinctrl_ops *ops = pctldev->desc->pctlops;
45 ops->dt_free_map(pctldev, map, num_maps);
47 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
52 void pinctrl_dt_free_maps(struct pinctrl *p)
54 struct pinctrl_dt_map *dt_map, *n1;
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,
64 of_node_put(p->dev->of_node);
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)
72 struct pinctrl_dt_map *dt_map;
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;
79 map[i].ctrl_dev_name = dev_name(pctldev->dev);
82 /* Remember the converted mapping table entries */
83 dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
85 dev_err(p->dev, "failed to alloc struct pinctrl_dt_map\n");
86 dt_free_map(pctldev, map, num_maps);
90 dt_map->pctldev = pctldev;
92 dt_map->num_maps = num_maps;
93 list_add_tail(&dt_map->node, &p->dt_maps);
95 return pinctrl_register_map(map, num_maps, false);
98 struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
100 return get_pinctrl_dev_from_of_node(np);
103 static int dt_to_map_one_config(struct pinctrl *p, const char *statename,
104 struct device_node *np_config)
106 struct device_node *np_pctldev;
107 struct pinctrl_dev *pctldev;
108 const struct pinctrl_ops *ops;
110 struct pinctrl_map *map;
113 /* Find the pin controller containing np_config */
114 np_pctldev = of_node_get(np_config);
116 np_pctldev = of_get_next_parent(np_pctldev);
117 if (!np_pctldev || of_node_is_root(np_pctldev)) {
118 dev_info(p->dev, "could not find pctldev for node %s, deferring probe\n",
119 np_config->full_name);
120 of_node_put(np_pctldev);
121 /* OK let's just assume this will appear later then */
122 return -EPROBE_DEFER;
124 pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
127 /* Do not defer probing of hogs (circular loop) */
128 if (np_pctldev == p->dev->of_node) {
129 of_node_put(np_pctldev);
133 of_node_put(np_pctldev);
136 * Call pinctrl driver to parse device tree node, and
137 * generate mapping table entries
139 ops = pctldev->desc->pctlops;
140 if (!ops->dt_node_to_map) {
141 dev_err(p->dev, "pctldev %s doesn't support DT\n",
142 dev_name(pctldev->dev));
145 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
149 /* Stash the mapping table chunk away for later use */
150 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
153 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
155 struct pinctrl_map *map;
157 map = kzalloc(sizeof(*map), GFP_KERNEL);
159 dev_err(p->dev, "failed to alloc struct pinctrl_map\n");
163 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
164 map->type = PIN_MAP_TYPE_DUMMY_STATE;
166 return dt_remember_or_free_map(p, statename, NULL, map, 1);
169 int pinctrl_dt_to_map(struct pinctrl *p)
171 struct device_node *np = p->dev->of_node;
174 struct property *prop;
175 const char *statename;
179 struct device_node *np_config;
181 /* CONFIG_OF enabled, p->dev not instantiated from DT */
183 if (of_have_populated_dt())
185 "no of_node; not parsing pinctrl DT\n");
189 /* We may store pointers to property names within the node */
192 /* For each defined state ID */
193 for (state = 0; ; state++) {
194 /* Retrieve the pinctrl-* property */
195 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
196 prop = of_find_property(np, propname, &size);
206 size /= sizeof(*list);
208 /* Determine whether pinctrl-names property names the state */
209 ret = of_property_read_string_index(np, "pinctrl-names",
212 * If not, statename is just the integer state ID. But rather
213 * than dynamically allocate it and have to free it later,
214 * just point part way into the property name for the string.
217 /* strlen("pinctrl-") == 8 */
218 statename = prop->name + 8;
221 /* For every referenced pin configuration node in it */
222 for (config = 0; config < size; config++) {
223 phandle = be32_to_cpup(list++);
225 /* Look up the pin configuration node */
226 np_config = of_find_node_by_phandle(phandle);
229 "prop %s index %i invalid phandle\n",
236 ret = dt_to_map_one_config(p, statename, np_config);
237 of_node_put(np_config);
242 /* No entries in DT? Generate a dummy state table entry */
244 ret = dt_remember_dummy_state(p, statename);
253 pinctrl_dt_free_maps(p);
258 * For pinctrl binding, typically #pinctrl-cells is for the pin controller
259 * device, so either parent or grandparent. See pinctrl-bindings.txt.
261 static int pinctrl_find_cells_size(const struct device_node *np)
263 const char *cells_name = "#pinctrl-cells";
264 int cells_size, error;
266 error = of_property_read_u32(np->parent, cells_name, &cells_size);
268 error = of_property_read_u32(np->parent->parent,
269 cells_name, &cells_size);
278 * pinctrl_get_list_and_count - Gets the list and it's cell size and number
279 * @np: pointer to device node with the property
280 * @list_name: property that contains the list
281 * @list: pointer for the list found
282 * @cells_size: pointer for the cell size found
283 * @nr_elements: pointer for the number of elements found
285 * Typically np is a single pinctrl entry containing the list.
287 static int pinctrl_get_list_and_count(const struct device_node *np,
288 const char *list_name,
298 *list = of_get_property(np, list_name, &size);
302 *cells_size = pinctrl_find_cells_size(np);
306 /* First element is always the index within the pinctrl device */
307 *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
313 * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
314 * @np: pointer to device node with the property
315 * @list_name: property that contains the list
317 * Counts the number of elements in a pinctrl array consisting of an index
318 * within the controller and a number of u32 entries specified for each
319 * entry. Note that device_node is always for the parent pin controller device.
321 int pinctrl_count_index_with_args(const struct device_node *np,
322 const char *list_name)
325 int size, nr_cells, error;
327 error = pinctrl_get_list_and_count(np, list_name, &list,
334 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
337 * pinctrl_copy_args - Populates of_phandle_args based on index
338 * @np: pointer to device node with the property
339 * @list: pointer to a list with the elements
340 * @index: entry within the list of elements
341 * @nr_cells: number of cells in the list
342 * @nr_elem: number of elements for each entry in the list
343 * @out_args: returned values
345 * Populates the of_phandle_args based on the index in the list.
347 static int pinctrl_copy_args(const struct device_node *np,
349 int index, int nr_cells, int nr_elem,
350 struct of_phandle_args *out_args)
354 memset(out_args, 0, sizeof(*out_args));
355 out_args->np = (struct device_node *)np;
356 out_args->args_count = nr_cells + 1;
358 if (index >= nr_elem)
361 list += index * (nr_cells + 1);
363 for (i = 0; i < nr_cells + 1; i++)
364 out_args->args[i] = be32_to_cpup(list++);
370 * pinctrl_parse_index_with_args - Find a node pointed by index in a list
371 * @np: pointer to device node with the property
372 * @list_name: property that contains the list
373 * @index: index within the list
374 * @out_arts: entries in the list pointed by index
376 * Finds the selected element in a pinctrl array consisting of an index
377 * within the controller and a number of u32 entries specified for each
378 * entry. Note that device_node is always for the parent pin controller device.
380 int pinctrl_parse_index_with_args(const struct device_node *np,
381 const char *list_name, int index,
382 struct of_phandle_args *out_args)
385 int nr_elem, nr_cells, error;
387 error = pinctrl_get_list_and_count(np, list_name, &list,
388 &nr_cells, &nr_elem);
389 if (error || !nr_cells)
392 error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
399 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);