Loading...
Note: File does not exist in v3.1.
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 */
33struct pinctrl_dt_map {
34 struct list_head node;
35 struct pinctrl_dev *pctldev;
36 struct pinctrl_map *map;
37 unsigned num_maps;
38};
39
40static void dt_free_map(struct pinctrl_dev *pctldev,
41 struct pinctrl_map *map, unsigned num_maps)
42{
43 if (pctldev) {
44 const struct pinctrl_ops *ops = pctldev->desc->pctlops;
45 if (ops->dt_free_map)
46 ops->dt_free_map(pctldev, map, num_maps);
47 } else {
48 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
49 kfree(map);
50 }
51}
52
53void pinctrl_dt_free_maps(struct pinctrl *p)
54{
55 struct pinctrl_dt_map *dt_map, *n1;
56
57 list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
58 pinctrl_unregister_map(dt_map->map);
59 list_del(&dt_map->node);
60 dt_free_map(dt_map->pctldev, dt_map->map,
61 dt_map->num_maps);
62 kfree(dt_map);
63 }
64
65 of_node_put(p->dev->of_node);
66}
67
68static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
69 struct pinctrl_dev *pctldev,
70 struct pinctrl_map *map, unsigned num_maps)
71{
72 int i;
73 struct pinctrl_dt_map *dt_map;
74
75 /* Initialize common mapping table entry fields */
76 for (i = 0; i < num_maps; i++) {
77 map[i].dev_name = dev_name(p->dev);
78 map[i].name = statename;
79 if (pctldev)
80 map[i].ctrl_dev_name = dev_name(pctldev->dev);
81 }
82
83 /* Remember the converted mapping table entries */
84 dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
85 if (!dt_map) {
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);
96}
97
98struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
99{
100 return get_pinctrl_dev_from_of_node(np);
101}
102
103static int dt_to_map_one_config(struct pinctrl *p,
104 struct pinctrl_dev *pctldev,
105 const char *statename,
106 struct device_node *np_config)
107{
108 struct device_node *np_pctldev;
109 const struct pinctrl_ops *ops;
110 int ret;
111 struct pinctrl_map *map;
112 unsigned num_maps;
113
114 /* Find the pin controller containing np_config */
115 np_pctldev = of_node_get(np_config);
116 for (;;) {
117 np_pctldev = of_get_next_parent(np_pctldev);
118 if (!np_pctldev || of_node_is_root(np_pctldev)) {
119 dev_info(p->dev, "could not find pctldev for node %pOF, deferring probe\n",
120 np_config);
121 of_node_put(np_pctldev);
122 /* OK let's just assume this will appear later then */
123 return -EPROBE_DEFER;
124 }
125 /* If we're creating a hog we can use the passed pctldev */
126 if (pctldev && (np_pctldev == p->dev->of_node))
127 break;
128 pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
129 if (pctldev)
130 break;
131 /* Do not defer probing of hogs (circular loop) */
132 if (np_pctldev == p->dev->of_node) {
133 of_node_put(np_pctldev);
134 return -ENODEV;
135 }
136 }
137 of_node_put(np_pctldev);
138
139 /*
140 * Call pinctrl driver to parse device tree node, and
141 * generate mapping table entries
142 */
143 ops = pctldev->desc->pctlops;
144 if (!ops->dt_node_to_map) {
145 dev_err(p->dev, "pctldev %s doesn't support DT\n",
146 dev_name(pctldev->dev));
147 return -ENODEV;
148 }
149 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
150 if (ret < 0)
151 return ret;
152
153 /* Stash the mapping table chunk away for later use */
154 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
155}
156
157static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
158{
159 struct pinctrl_map *map;
160
161 map = kzalloc(sizeof(*map), GFP_KERNEL);
162 if (!map)
163 return -ENOMEM;
164
165 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
166 map->type = PIN_MAP_TYPE_DUMMY_STATE;
167
168 return dt_remember_or_free_map(p, statename, NULL, map, 1);
169}
170
171bool pinctrl_dt_has_hogs(struct pinctrl_dev *pctldev)
172{
173 struct device_node *np;
174 struct property *prop;
175 int size;
176
177 np = pctldev->dev->of_node;
178 if (!np)
179 return false;
180
181 prop = of_find_property(np, "pinctrl-0", &size);
182
183 return prop ? true : false;
184}
185
186int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
187{
188 struct device_node *np = p->dev->of_node;
189 int state, ret;
190 char *propname;
191 struct property *prop;
192 const char *statename;
193 const __be32 *list;
194 int size, config;
195 phandle phandle;
196 struct device_node *np_config;
197
198 /* CONFIG_OF enabled, p->dev not instantiated from DT */
199 if (!np) {
200 if (of_have_populated_dt())
201 dev_dbg(p->dev,
202 "no of_node; not parsing pinctrl DT\n");
203 return 0;
204 }
205
206 /* We may store pointers to property names within the node */
207 of_node_get(np);
208
209 /* For each defined state ID */
210 for (state = 0; ; state++) {
211 /* Retrieve the pinctrl-* property */
212 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
213 prop = of_find_property(np, propname, &size);
214 kfree(propname);
215 if (!prop) {
216 if (state == 0) {
217 of_node_put(np);
218 return -ENODEV;
219 }
220 break;
221 }
222 list = prop->value;
223 size /= sizeof(*list);
224
225 /* Determine whether pinctrl-names property names the state */
226 ret = of_property_read_string_index(np, "pinctrl-names",
227 state, &statename);
228 /*
229 * If not, statename is just the integer state ID. But rather
230 * than dynamically allocate it and have to free it later,
231 * just point part way into the property name for the string.
232 */
233 if (ret < 0) {
234 /* strlen("pinctrl-") == 8 */
235 statename = prop->name + 8;
236 }
237
238 /* For every referenced pin configuration node in it */
239 for (config = 0; config < size; config++) {
240 phandle = be32_to_cpup(list++);
241
242 /* Look up the pin configuration node */
243 np_config = of_find_node_by_phandle(phandle);
244 if (!np_config) {
245 dev_err(p->dev,
246 "prop %s index %i invalid phandle\n",
247 prop->name, config);
248 ret = -EINVAL;
249 goto err;
250 }
251
252 /* Parse the node */
253 ret = dt_to_map_one_config(p, pctldev, statename,
254 np_config);
255 of_node_put(np_config);
256 if (ret < 0)
257 goto err;
258 }
259
260 /* No entries in DT? Generate a dummy state table entry */
261 if (!size) {
262 ret = dt_remember_dummy_state(p, statename);
263 if (ret < 0)
264 goto err;
265 }
266 }
267
268 return 0;
269
270err:
271 pinctrl_dt_free_maps(p);
272 return ret;
273}
274
275/*
276 * For pinctrl binding, typically #pinctrl-cells is for the pin controller
277 * device, so either parent or grandparent. See pinctrl-bindings.txt.
278 */
279static int pinctrl_find_cells_size(const struct device_node *np)
280{
281 const char *cells_name = "#pinctrl-cells";
282 int cells_size, error;
283
284 error = of_property_read_u32(np->parent, cells_name, &cells_size);
285 if (error) {
286 error = of_property_read_u32(np->parent->parent,
287 cells_name, &cells_size);
288 if (error)
289 return -ENOENT;
290 }
291
292 return cells_size;
293}
294
295/**
296 * pinctrl_get_list_and_count - Gets the list and it's cell size and number
297 * @np: pointer to device node with the property
298 * @list_name: property that contains the list
299 * @list: pointer for the list found
300 * @cells_size: pointer for the cell size found
301 * @nr_elements: pointer for the number of elements found
302 *
303 * Typically np is a single pinctrl entry containing the list.
304 */
305static int pinctrl_get_list_and_count(const struct device_node *np,
306 const char *list_name,
307 const __be32 **list,
308 int *cells_size,
309 int *nr_elements)
310{
311 int size;
312
313 *cells_size = 0;
314 *nr_elements = 0;
315
316 *list = of_get_property(np, list_name, &size);
317 if (!*list)
318 return -ENOENT;
319
320 *cells_size = pinctrl_find_cells_size(np);
321 if (*cells_size < 0)
322 return -ENOENT;
323
324 /* First element is always the index within the pinctrl device */
325 *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
326
327 return 0;
328}
329
330/**
331 * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
332 * @np: pointer to device node with the property
333 * @list_name: property that contains the list
334 *
335 * Counts the number of elements in a pinctrl array consisting of an index
336 * within the controller and a number of u32 entries specified for each
337 * entry. Note that device_node is always for the parent pin controller device.
338 */
339int pinctrl_count_index_with_args(const struct device_node *np,
340 const char *list_name)
341{
342 const __be32 *list;
343 int size, nr_cells, error;
344
345 error = pinctrl_get_list_and_count(np, list_name, &list,
346 &nr_cells, &size);
347 if (error)
348 return error;
349
350 return size;
351}
352EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
353
354/**
355 * pinctrl_copy_args - Populates of_phandle_args based on index
356 * @np: pointer to device node with the property
357 * @list: pointer to a list with the elements
358 * @index: entry within the list of elements
359 * @nr_cells: number of cells in the list
360 * @nr_elem: number of elements for each entry in the list
361 * @out_args: returned values
362 *
363 * Populates the of_phandle_args based on the index in the list.
364 */
365static int pinctrl_copy_args(const struct device_node *np,
366 const __be32 *list,
367 int index, int nr_cells, int nr_elem,
368 struct of_phandle_args *out_args)
369{
370 int i;
371
372 memset(out_args, 0, sizeof(*out_args));
373 out_args->np = (struct device_node *)np;
374 out_args->args_count = nr_cells + 1;
375
376 if (index >= nr_elem)
377 return -EINVAL;
378
379 list += index * (nr_cells + 1);
380
381 for (i = 0; i < nr_cells + 1; i++)
382 out_args->args[i] = be32_to_cpup(list++);
383
384 return 0;
385}
386
387/**
388 * pinctrl_parse_index_with_args - Find a node pointed by index in a list
389 * @np: pointer to device node with the property
390 * @list_name: property that contains the list
391 * @index: index within the list
392 * @out_arts: entries in the list pointed by index
393 *
394 * Finds the selected element in a pinctrl array consisting of an index
395 * within the controller and a number of u32 entries specified for each
396 * entry. Note that device_node is always for the parent pin controller device.
397 */
398int pinctrl_parse_index_with_args(const struct device_node *np,
399 const char *list_name, int index,
400 struct of_phandle_args *out_args)
401{
402 const __be32 *list;
403 int nr_elem, nr_cells, error;
404
405 error = pinctrl_get_list_and_count(np, list_name, &list,
406 &nr_cells, &nr_elem);
407 if (error || !nr_cells)
408 return error;
409
410 error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
411 out_args);
412 if (error)
413 return error;
414
415 return 0;
416}
417EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);