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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 | const 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); | |
96 | } | |
97 | ||
98 | struct pinctrl_dev *of_pinctrl_get(struct device_node *np) | |
99 | { | |
100 | return get_pinctrl_dev_from_of_node(np); | |
101 | } | |
102 | ||
103 | static int dt_to_map_one_config(struct pinctrl *p, const char *statename, | |
104 | struct device_node *np_config) | |
105 | { | |
106 | struct device_node *np_pctldev; | |
107 | struct pinctrl_dev *pctldev; | |
108 | const struct pinctrl_ops *ops; | |
109 | int ret; | |
110 | struct pinctrl_map *map; | |
111 | unsigned num_maps; | |
112 | ||
113 | /* Find the pin controller containing np_config */ | |
114 | np_pctldev = of_node_get(np_config); | |
115 | for (;;) { | |
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; | |
123 | } | |
124 | pctldev = get_pinctrl_dev_from_of_node(np_pctldev); | |
125 | if (pctldev) | |
126 | break; | |
127 | /* Do not defer probing of hogs (circular loop) */ | |
128 | if (np_pctldev == p->dev->of_node) { | |
129 | of_node_put(np_pctldev); | |
130 | return -ENODEV; | |
131 | } | |
132 | } | |
133 | of_node_put(np_pctldev); | |
134 | ||
135 | /* | |
136 | * Call pinctrl driver to parse device tree node, and | |
137 | * generate mapping table entries | |
138 | */ | |
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)); | |
143 | return -ENODEV; | |
144 | } | |
145 | ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps); | |
146 | if (ret < 0) | |
147 | return ret; | |
148 | ||
149 | /* Stash the mapping table chunk away for later use */ | |
150 | return dt_remember_or_free_map(p, statename, pctldev, map, num_maps); | |
151 | } | |
152 | ||
153 | static int dt_remember_dummy_state(struct pinctrl *p, const char *statename) | |
154 | { | |
155 | struct pinctrl_map *map; | |
156 | ||
157 | map = kzalloc(sizeof(*map), GFP_KERNEL); | |
158 | if (!map) { | |
159 | dev_err(p->dev, "failed to alloc struct pinctrl_map\n"); | |
160 | return -ENOMEM; | |
161 | } | |
162 | ||
163 | /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ | |
164 | map->type = PIN_MAP_TYPE_DUMMY_STATE; | |
165 | ||
166 | return dt_remember_or_free_map(p, statename, NULL, map, 1); | |
167 | } | |
168 | ||
169 | int pinctrl_dt_to_map(struct pinctrl *p) | |
170 | { | |
171 | struct device_node *np = p->dev->of_node; | |
172 | int state, ret; | |
173 | char *propname; | |
174 | struct property *prop; | |
175 | const char *statename; | |
176 | const __be32 *list; | |
177 | int size, config; | |
178 | phandle phandle; | |
179 | struct device_node *np_config; | |
180 | ||
181 | /* CONFIG_OF enabled, p->dev not instantiated from DT */ | |
182 | if (!np) { | |
183 | if (of_have_populated_dt()) | |
184 | dev_dbg(p->dev, | |
185 | "no of_node; not parsing pinctrl DT\n"); | |
186 | return 0; | |
187 | } | |
188 | ||
189 | /* We may store pointers to property names within the node */ | |
190 | of_node_get(np); | |
191 | ||
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); | |
197 | kfree(propname); | |
198 | if (!prop) { | |
199 | if (state == 0) { | |
200 | of_node_put(np); | |
201 | return -ENODEV; | |
202 | } | |
203 | break; | |
204 | } | |
205 | list = prop->value; | |
206 | size /= sizeof(*list); | |
207 | ||
208 | /* Determine whether pinctrl-names property names the state */ | |
209 | ret = of_property_read_string_index(np, "pinctrl-names", | |
210 | state, &statename); | |
211 | /* | |
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. | |
215 | */ | |
216 | if (ret < 0) { | |
217 | /* strlen("pinctrl-") == 8 */ | |
218 | statename = prop->name + 8; | |
219 | } | |
220 | ||
221 | /* For every referenced pin configuration node in it */ | |
222 | for (config = 0; config < size; config++) { | |
223 | phandle = be32_to_cpup(list++); | |
224 | ||
225 | /* Look up the pin configuration node */ | |
226 | np_config = of_find_node_by_phandle(phandle); | |
227 | if (!np_config) { | |
228 | dev_err(p->dev, | |
229 | "prop %s index %i invalid phandle\n", | |
230 | prop->name, config); | |
231 | ret = -EINVAL; | |
232 | goto err; | |
233 | } | |
234 | ||
235 | /* Parse the node */ | |
236 | ret = dt_to_map_one_config(p, statename, np_config); | |
237 | of_node_put(np_config); | |
238 | if (ret < 0) | |
239 | goto err; | |
240 | } | |
241 | ||
242 | /* No entries in DT? Generate a dummy state table entry */ | |
243 | if (!size) { | |
244 | ret = dt_remember_dummy_state(p, statename); | |
245 | if (ret < 0) | |
246 | goto err; | |
247 | } | |
248 | } | |
249 | ||
250 | return 0; | |
251 | ||
252 | err: | |
253 | pinctrl_dt_free_maps(p); | |
254 | return ret; | |
255 | } | |
256 | ||
257 | /* | |
258 | * For pinctrl binding, typically #pinctrl-cells is for the pin controller | |
259 | * device, so either parent or grandparent. See pinctrl-bindings.txt. | |
260 | */ | |
261 | static int pinctrl_find_cells_size(const struct device_node *np) | |
262 | { | |
263 | const char *cells_name = "#pinctrl-cells"; | |
264 | int cells_size, error; | |
265 | ||
266 | error = of_property_read_u32(np->parent, cells_name, &cells_size); | |
267 | if (error) { | |
268 | error = of_property_read_u32(np->parent->parent, | |
269 | cells_name, &cells_size); | |
270 | if (error) | |
271 | return -ENOENT; | |
272 | } | |
273 | ||
274 | return cells_size; | |
275 | } | |
276 | ||
277 | /** | |
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 | |
284 | * | |
285 | * Typically np is a single pinctrl entry containing the list. | |
286 | */ | |
287 | static int pinctrl_get_list_and_count(const struct device_node *np, | |
288 | const char *list_name, | |
289 | const __be32 **list, | |
290 | int *cells_size, | |
291 | int *nr_elements) | |
292 | { | |
293 | int size; | |
294 | ||
295 | *cells_size = 0; | |
296 | *nr_elements = 0; | |
297 | ||
298 | *list = of_get_property(np, list_name, &size); | |
299 | if (!*list) | |
300 | return -ENOENT; | |
301 | ||
302 | *cells_size = pinctrl_find_cells_size(np); | |
303 | if (*cells_size < 0) | |
304 | return -ENOENT; | |
305 | ||
306 | /* First element is always the index within the pinctrl device */ | |
307 | *nr_elements = (size / sizeof(**list)) / (*cells_size + 1); | |
308 | ||
309 | return 0; | |
310 | } | |
311 | ||
312 | /** | |
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 | |
316 | * | |
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. | |
320 | */ | |
321 | int pinctrl_count_index_with_args(const struct device_node *np, | |
322 | const char *list_name) | |
323 | { | |
324 | const __be32 *list; | |
325 | int size, nr_cells, error; | |
326 | ||
327 | error = pinctrl_get_list_and_count(np, list_name, &list, | |
328 | &nr_cells, &size); | |
329 | if (error) | |
330 | return error; | |
331 | ||
332 | return size; | |
333 | } | |
334 | EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args); | |
335 | ||
336 | /** | |
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 | |
344 | * | |
345 | * Populates the of_phandle_args based on the index in the list. | |
346 | */ | |
347 | static int pinctrl_copy_args(const struct device_node *np, | |
348 | const __be32 *list, | |
349 | int index, int nr_cells, int nr_elem, | |
350 | struct of_phandle_args *out_args) | |
351 | { | |
352 | int i; | |
353 | ||
354 | memset(out_args, 0, sizeof(*out_args)); | |
355 | out_args->np = (struct device_node *)np; | |
356 | out_args->args_count = nr_cells + 1; | |
357 | ||
358 | if (index >= nr_elem) | |
359 | return -EINVAL; | |
360 | ||
361 | list += index * (nr_cells + 1); | |
362 | ||
363 | for (i = 0; i < nr_cells + 1; i++) | |
364 | out_args->args[i] = be32_to_cpup(list++); | |
365 | ||
366 | return 0; | |
367 | } | |
368 | ||
369 | /** | |
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 | |
375 | * | |
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. | |
379 | */ | |
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) | |
383 | { | |
384 | const __be32 *list; | |
385 | int nr_elem, nr_cells, error; | |
386 | ||
387 | error = pinctrl_get_list_and_count(np, list_name, &list, | |
388 | &nr_cells, &nr_elem); | |
389 | if (error || !nr_cells) | |
390 | return error; | |
391 | ||
392 | error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem, | |
393 | out_args); | |
394 | if (error) | |
395 | return error; | |
396 | ||
397 | return 0; | |
398 | } | |
399 | EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args); |