Loading...
Note: File does not exist in v3.1.
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Device tree integration for the pin control subsystem
4 *
5 * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
6 */
7
8#include <linux/device.h>
9#include <linux/of.h>
10#include <linux/pinctrl/pinctrl.h>
11#include <linux/slab.h>
12
13#include "core.h"
14#include "devicetree.h"
15
16/**
17 * struct pinctrl_dt_map - mapping table chunk parsed from device tree
18 * @node: list node for struct pinctrl's @dt_maps field
19 * @pctldev: the pin controller that allocated this struct, and will free it
20 * @map: the mapping table entries
21 * @num_maps: number of mapping table entries
22 */
23struct pinctrl_dt_map {
24 struct list_head node;
25 struct pinctrl_dev *pctldev;
26 struct pinctrl_map *map;
27 unsigned num_maps;
28};
29
30static void dt_free_map(struct pinctrl_dev *pctldev,
31 struct pinctrl_map *map, unsigned num_maps)
32{
33 int i;
34
35 for (i = 0; i < num_maps; ++i) {
36 kfree_const(map[i].dev_name);
37 map[i].dev_name = NULL;
38 }
39
40 if (pctldev) {
41 const struct pinctrl_ops *ops = pctldev->desc->pctlops;
42 if (ops->dt_free_map)
43 ops->dt_free_map(pctldev, map, num_maps);
44 } else {
45 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
46 kfree(map);
47 }
48}
49
50void pinctrl_dt_free_maps(struct pinctrl *p)
51{
52 struct pinctrl_dt_map *dt_map, *n1;
53
54 list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
55 pinctrl_unregister_mappings(dt_map->map);
56 list_del(&dt_map->node);
57 dt_free_map(dt_map->pctldev, dt_map->map,
58 dt_map->num_maps);
59 kfree(dt_map);
60 }
61
62 of_node_put(p->dev->of_node);
63}
64
65static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
66 struct pinctrl_dev *pctldev,
67 struct pinctrl_map *map, unsigned num_maps)
68{
69 int i;
70 struct pinctrl_dt_map *dt_map;
71
72 /* Initialize common mapping table entry fields */
73 for (i = 0; i < num_maps; i++) {
74 const char *devname;
75
76 devname = kstrdup_const(dev_name(p->dev), GFP_KERNEL);
77 if (!devname)
78 goto err_free_map;
79
80 map[i].dev_name = devname;
81 map[i].name = statename;
82 if (pctldev)
83 map[i].ctrl_dev_name = dev_name(pctldev->dev);
84 }
85
86 /* Remember the converted mapping table entries */
87 dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
88 if (!dt_map)
89 goto err_free_map;
90
91 dt_map->pctldev = pctldev;
92 dt_map->map = map;
93 dt_map->num_maps = num_maps;
94 list_add_tail(&dt_map->node, &p->dt_maps);
95
96 return pinctrl_register_mappings(map, num_maps);
97
98err_free_map:
99 dt_free_map(pctldev, map, num_maps);
100 return -ENOMEM;
101}
102
103struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
104{
105 return get_pinctrl_dev_from_of_node(np);
106}
107EXPORT_SYMBOL_GPL(of_pinctrl_get);
108
109static int dt_to_map_one_config(struct pinctrl *p,
110 struct pinctrl_dev *hog_pctldev,
111 const char *statename,
112 struct device_node *np_config)
113{
114 struct pinctrl_dev *pctldev = NULL;
115 struct device_node *np_pctldev;
116 const struct pinctrl_ops *ops;
117 int ret;
118 struct pinctrl_map *map;
119 unsigned num_maps;
120 bool allow_default = false;
121
122 /* Find the pin controller containing np_config */
123 np_pctldev = of_node_get(np_config);
124 for (;;) {
125 if (!allow_default)
126 allow_default = of_property_read_bool(np_pctldev,
127 "pinctrl-use-default");
128
129 np_pctldev = of_get_next_parent(np_pctldev);
130 if (!np_pctldev || of_node_is_root(np_pctldev)) {
131 of_node_put(np_pctldev);
132 ret = driver_deferred_probe_check_state(p->dev);
133 /* keep deferring if modules are enabled unless we've timed out */
134 if (IS_ENABLED(CONFIG_MODULES) && !allow_default &&
135 (ret == -ENODEV))
136 ret = -EPROBE_DEFER;
137 return ret;
138 }
139 /* If we're creating a hog we can use the passed pctldev */
140 if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
141 pctldev = hog_pctldev;
142 break;
143 }
144 pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
145 if (pctldev)
146 break;
147 /* Do not defer probing of hogs (circular loop) */
148 if (np_pctldev == p->dev->of_node) {
149 of_node_put(np_pctldev);
150 return -ENODEV;
151 }
152 }
153 of_node_put(np_pctldev);
154
155 /*
156 * Call pinctrl driver to parse device tree node, and
157 * generate mapping table entries
158 */
159 ops = pctldev->desc->pctlops;
160 if (!ops->dt_node_to_map) {
161 dev_err(p->dev, "pctldev %s doesn't support DT\n",
162 dev_name(pctldev->dev));
163 return -ENODEV;
164 }
165 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
166 if (ret < 0)
167 return ret;
168 else if (num_maps == 0) {
169 /*
170 * If we have no valid maps (maybe caused by empty pinctrl node
171 * or typing error) ther is no need remember this, so just
172 * return.
173 */
174 dev_info(p->dev,
175 "there is not valid maps for state %s\n", statename);
176 return 0;
177 }
178
179 /* Stash the mapping table chunk away for later use */
180 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
181}
182
183static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
184{
185 struct pinctrl_map *map;
186
187 map = kzalloc(sizeof(*map), GFP_KERNEL);
188 if (!map)
189 return -ENOMEM;
190
191 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
192 map->type = PIN_MAP_TYPE_DUMMY_STATE;
193
194 return dt_remember_or_free_map(p, statename, NULL, map, 1);
195}
196
197int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
198{
199 struct device_node *np = p->dev->of_node;
200 int state, ret;
201 char *propname;
202 struct property *prop;
203 const char *statename;
204 const __be32 *list;
205 int size, config;
206 phandle phandle;
207 struct device_node *np_config;
208
209 /* CONFIG_OF enabled, p->dev not instantiated from DT */
210 if (!np) {
211 if (of_have_populated_dt())
212 dev_dbg(p->dev,
213 "no of_node; not parsing pinctrl DT\n");
214 return 0;
215 }
216
217 /* We may store pointers to property names within the node */
218 of_node_get(np);
219
220 /* For each defined state ID */
221 for (state = 0; ; state++) {
222 /* Retrieve the pinctrl-* property */
223 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
224 prop = of_find_property(np, propname, &size);
225 kfree(propname);
226 if (!prop) {
227 if (state == 0) {
228 of_node_put(np);
229 return -ENODEV;
230 }
231 break;
232 }
233 list = prop->value;
234 size /= sizeof(*list);
235
236 /* Determine whether pinctrl-names property names the state */
237 ret = of_property_read_string_index(np, "pinctrl-names",
238 state, &statename);
239 /*
240 * If not, statename is just the integer state ID. But rather
241 * than dynamically allocate it and have to free it later,
242 * just point part way into the property name for the string.
243 */
244 if (ret < 0)
245 statename = prop->name + strlen("pinctrl-");
246
247 /* For every referenced pin configuration node in it */
248 for (config = 0; config < size; config++) {
249 phandle = be32_to_cpup(list++);
250
251 /* Look up the pin configuration node */
252 np_config = of_find_node_by_phandle(phandle);
253 if (!np_config) {
254 dev_err(p->dev,
255 "prop %s index %i invalid phandle\n",
256 prop->name, config);
257 ret = -EINVAL;
258 goto err;
259 }
260
261 /* Parse the node */
262 ret = dt_to_map_one_config(p, pctldev, statename,
263 np_config);
264 of_node_put(np_config);
265 if (ret < 0)
266 goto err;
267 }
268
269 /* No entries in DT? Generate a dummy state table entry */
270 if (!size) {
271 ret = dt_remember_dummy_state(p, statename);
272 if (ret < 0)
273 goto err;
274 }
275 }
276
277 return 0;
278
279err:
280 pinctrl_dt_free_maps(p);
281 return ret;
282}
283
284/*
285 * For pinctrl binding, typically #pinctrl-cells is for the pin controller
286 * device, so either parent or grandparent. See pinctrl-bindings.txt.
287 */
288static int pinctrl_find_cells_size(const struct device_node *np)
289{
290 const char *cells_name = "#pinctrl-cells";
291 int cells_size, error;
292
293 error = of_property_read_u32(np->parent, cells_name, &cells_size);
294 if (error) {
295 error = of_property_read_u32(np->parent->parent,
296 cells_name, &cells_size);
297 if (error)
298 return -ENOENT;
299 }
300
301 return cells_size;
302}
303
304/**
305 * pinctrl_get_list_and_count - Gets the list and it's cell size and number
306 * @np: pointer to device node with the property
307 * @list_name: property that contains the list
308 * @list: pointer for the list found
309 * @cells_size: pointer for the cell size found
310 * @nr_elements: pointer for the number of elements found
311 *
312 * Typically np is a single pinctrl entry containing the list.
313 */
314static int pinctrl_get_list_and_count(const struct device_node *np,
315 const char *list_name,
316 const __be32 **list,
317 int *cells_size,
318 int *nr_elements)
319{
320 int size;
321
322 *cells_size = 0;
323 *nr_elements = 0;
324
325 *list = of_get_property(np, list_name, &size);
326 if (!*list)
327 return -ENOENT;
328
329 *cells_size = pinctrl_find_cells_size(np);
330 if (*cells_size < 0)
331 return -ENOENT;
332
333 /* First element is always the index within the pinctrl device */
334 *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
335
336 return 0;
337}
338
339/**
340 * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
341 * @np: pointer to device node with the property
342 * @list_name: property that contains the list
343 *
344 * Counts the number of elements in a pinctrl array consisting of an index
345 * within the controller and a number of u32 entries specified for each
346 * entry. Note that device_node is always for the parent pin controller device.
347 */
348int pinctrl_count_index_with_args(const struct device_node *np,
349 const char *list_name)
350{
351 const __be32 *list;
352 int size, nr_cells, error;
353
354 error = pinctrl_get_list_and_count(np, list_name, &list,
355 &nr_cells, &size);
356 if (error)
357 return error;
358
359 return size;
360}
361EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
362
363/**
364 * pinctrl_copy_args - Populates of_phandle_args based on index
365 * @np: pointer to device node with the property
366 * @list: pointer to a list with the elements
367 * @index: entry within the list of elements
368 * @nr_cells: number of cells in the list
369 * @nr_elem: number of elements for each entry in the list
370 * @out_args: returned values
371 *
372 * Populates the of_phandle_args based on the index in the list.
373 */
374static int pinctrl_copy_args(const struct device_node *np,
375 const __be32 *list,
376 int index, int nr_cells, int nr_elem,
377 struct of_phandle_args *out_args)
378{
379 int i;
380
381 memset(out_args, 0, sizeof(*out_args));
382 out_args->np = (struct device_node *)np;
383 out_args->args_count = nr_cells + 1;
384
385 if (index >= nr_elem)
386 return -EINVAL;
387
388 list += index * (nr_cells + 1);
389
390 for (i = 0; i < nr_cells + 1; i++)
391 out_args->args[i] = be32_to_cpup(list++);
392
393 return 0;
394}
395
396/**
397 * pinctrl_parse_index_with_args - Find a node pointed by index in a list
398 * @np: pointer to device node with the property
399 * @list_name: property that contains the list
400 * @index: index within the list
401 * @out_args: entries in the list pointed by index
402 *
403 * Finds the selected element in a pinctrl array consisting of an index
404 * within the controller and a number of u32 entries specified for each
405 * entry. Note that device_node is always for the parent pin controller device.
406 */
407int pinctrl_parse_index_with_args(const struct device_node *np,
408 const char *list_name, int index,
409 struct of_phandle_args *out_args)
410{
411 const __be32 *list;
412 int nr_elem, nr_cells, error;
413
414 error = pinctrl_get_list_and_count(np, list_name, &list,
415 &nr_cells, &nr_elem);
416 if (error || !nr_cells)
417 return error;
418
419 error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
420 out_args);
421 if (error)
422 return error;
423
424 return 0;
425}
426EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);