projects/linux·blob master · refs

439 lines · 11.1 KiB

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 int num_maps;
28};
29
30static void dt_free_map(struct pinctrl_dev *pctldev,
31 struct pinctrl_map *map, unsigned int 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 int num_maps)
68{
69 int i;
70 struct pinctrl_dt_map *dt_map;
71
72 /* Initialize dev_name before any allocation can fail */
73 for (i = 0; i < num_maps; i++)
74 map[i].dev_name = NULL;
75
76 /* Initialize common mapping table entry fields */
77 for (i = 0; i < num_maps; i++) {
78 const char *devname;
79
80 devname = kstrdup_const(dev_name(p->dev), GFP_KERNEL);
81 if (!devname)
82 goto err_free_map;
83
84 map[i].dev_name = devname;
85 map[i].name = statename;
86 if (pctldev)
87 map[i].ctrl_dev_name = dev_name(pctldev->dev);
88 }
89
90 /* Remember the converted mapping table entries */
91 dt_map = kzalloc_obj(*dt_map);
92 if (!dt_map)
93 goto err_free_map;
94
95 dt_map->pctldev = pctldev;
96 dt_map->map = map;
97 dt_map->num_maps = num_maps;
98 list_add_tail(&dt_map->node, &p->dt_maps);
99
100 return pinctrl_register_mappings(map, num_maps);
101
102err_free_map:
103 dt_free_map(pctldev, map, num_maps);
104 return -ENOMEM;
105}
106
107struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
108{
109 return get_pinctrl_dev_from_of_node(np);
110}
111EXPORT_SYMBOL_GPL(of_pinctrl_get);
112
113static int dt_to_map_one_config(struct pinctrl *p,
114 struct pinctrl_dev *hog_pctldev,
115 const char *statename,
116 struct device_node *np_config)
117{
118 struct pinctrl_dev *pctldev = NULL;
119 struct device_node *np_pctldev;
120 const struct pinctrl_ops *ops;
121 int ret;
122 struct pinctrl_map *map;
123 unsigned int num_maps;
124 bool allow_default = false;
125
126 /* Find the pin controller containing np_config */
127 np_pctldev = of_node_get(np_config);
128 for (;;) {
129 if (!allow_default)
130 allow_default = of_property_read_bool(np_pctldev,
131 "pinctrl-use-default");
132
133 np_pctldev = of_get_next_parent(np_pctldev);
134 if (!np_pctldev || of_node_is_root(np_pctldev)) {
135 of_node_put(np_pctldev);
136 ret = -ENODEV;
137 /* keep deferring if modules are enabled */
138 if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret < 0)
139 ret = -EPROBE_DEFER;
140 return ret;
141 }
142 /* If we're creating a hog we can use the passed pctldev */
143 if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
144 pctldev = hog_pctldev;
145 break;
146 }
147 pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
148 if (pctldev)
149 break;
150 /*
151 * Do not defer probing of hogs (circular loop)
152 *
153 * Return 1 to let the caller catch the case.
154 */
155 if (np_pctldev == p->dev->of_node) {
156 of_node_put(np_pctldev);
157 return 1;
158 }
159 }
160 of_node_put(np_pctldev);
161
162 /*
163 * Call pinctrl driver to parse device tree node, and
164 * generate mapping table entries
165 */
166 ops = pctldev->desc->pctlops;
167 if (!ops->dt_node_to_map) {
168 dev_err(p->dev, "pctldev %s doesn't support DT\n",
169 dev_name(pctldev->dev));
170 return -ENODEV;
171 }
172 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
173 if (ret < 0)
174 return ret;
175 else if (num_maps == 0) {
176 /*
177 * If we have no valid maps (maybe caused by empty pinctrl node
178 * or typing error) ther is no need remember this, so just
179 * return.
180 */
181 dev_info(p->dev,
182 "there are no valid maps for state %s\n", statename);
183 return 0;
184 }
185
186 /* Stash the mapping table chunk away for later use */
187 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
188}
189
190static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
191{
192 struct pinctrl_map *map;
193
194 map = kzalloc_obj(*map);
195 if (!map)
196 return -ENOMEM;
197
198 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
199 map->type = PIN_MAP_TYPE_DUMMY_STATE;
200
201 return dt_remember_or_free_map(p, statename, NULL, map, 1);
202}
203
204int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
205{
206 struct device_node *np = p->dev->of_node;
207 int state, ret;
208 char *propname;
209 struct property *prop;
210 const char *statename;
211 const __be32 *list;
212 int size, config;
213 phandle phandle;
214 struct device_node *np_config;
215
216 /* CONFIG_OF enabled, p->dev not instantiated from DT */
217 if (!np) {
218 if (of_have_populated_dt())
219 dev_dbg(p->dev,
220 "no of_node; not parsing pinctrl DT\n");
221 return 0;
222 }
223
224 /* We may store pointers to property names within the node */
225 of_node_get(np);
226
227 /* For each defined state ID */
228 for (state = 0; ; state++) {
229 /* Retrieve the pinctrl-* property */
230 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
231 if (!propname) {
232 ret = -ENOMEM;
233 goto err;
234 }
235 prop = of_find_property(np, propname, &size);
236 kfree(propname);
237 if (!prop) {
238 if (state == 0) {
239 ret = -ENODEV;
240 goto err;
241 }
242 break;
243 }
244 list = prop->value;
245 size /= sizeof(*list);
246
247 /* Determine whether pinctrl-names property names the state */
248 ret = of_property_read_string_index(np, "pinctrl-names",
249 state, &statename);
250 /*
251 * If not, statename is just the integer state ID. But rather
252 * than dynamically allocate it and have to free it later,
253 * just point part way into the property name for the string.
254 */
255 if (ret < 0)
256 statename = prop->name + strlen("pinctrl-");
257
258 /* For every referenced pin configuration node in it */
259 for (config = 0; config < size; config++) {
260 phandle = be32_to_cpup(list++);
261
262 /* Look up the pin configuration node */
263 np_config = of_find_node_by_phandle(phandle);
264 if (!np_config) {
265 dev_err(p->dev,
266 "prop %s index %i invalid phandle\n",
267 prop->name, config);
268 ret = -EINVAL;
269 goto err;
270 }
271
272 /* Parse the node */
273 ret = dt_to_map_one_config(p, pctldev, statename,
274 np_config);
275 of_node_put(np_config);
276 if (ret == 1)
277 continue;
278 if (ret < 0)
279 goto err;
280 }
281
282 /* No entries in DT? Generate a dummy state table entry */
283 if (!size) {
284 ret = dt_remember_dummy_state(p, statename);
285 if (ret < 0)
286 goto err;
287 }
288 }
289
290 return 0;
291
292err:
293 pinctrl_dt_free_maps(p);
294 return ret;
295}
296
297/*
298 * For pinctrl binding, typically #pinctrl-cells is for the pin controller
299 * device, so either parent or grandparent. See pinctrl-bindings.txt.
300 */
301static int pinctrl_find_cells_size(const struct device_node *np)
302{
303 const char *cells_name = "#pinctrl-cells";
304 int cells_size, error;
305
306 error = of_property_read_u32(np->parent, cells_name, &cells_size);
307 if (error) {
308 error = of_property_read_u32(np->parent->parent,
309 cells_name, &cells_size);
310 if (error)
311 return -ENOENT;
312 }
313
314 return cells_size;
315}
316
317/**
318 * pinctrl_get_list_and_count - Gets the list and it's cell size and number
319 * @np: pointer to device node with the property
320 * @list_name: property that contains the list
321 * @list: pointer for the list found
322 * @cells_size: pointer for the cell size found
323 * @nr_elements: pointer for the number of elements found
324 *
325 * Typically np is a single pinctrl entry containing the list.
326 */
327static int pinctrl_get_list_and_count(const struct device_node *np,
328 const char *list_name,
329 const __be32 **list,
330 int *cells_size,
331 int *nr_elements)
332{
333 int size;
334
335 *cells_size = 0;
336 *nr_elements = 0;
337
338 *list = of_get_property(np, list_name, &size);
339 if (!*list)
340 return -ENOENT;
341
342 *cells_size = pinctrl_find_cells_size(np);
343 if (*cells_size < 0)
344 return -ENOENT;
345
346 /* First element is always the index within the pinctrl device */
347 *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
348
349 return 0;
350}
351
352/**
353 * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
354 * @np: pointer to device node with the property
355 * @list_name: property that contains the list
356 *
357 * Counts the number of elements in a pinctrl array consisting of an index
358 * within the controller and a number of u32 entries specified for each
359 * entry. Note that device_node is always for the parent pin controller device.
360 */
361int pinctrl_count_index_with_args(const struct device_node *np,
362 const char *list_name)
363{
364 const __be32 *list;
365 int size, nr_cells, error;
366
367 error = pinctrl_get_list_and_count(np, list_name, &list,
368 &nr_cells, &size);
369 if (error)
370 return error;
371
372 return size;
373}
374EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
375
376/**
377 * pinctrl_copy_args - Populates of_phandle_args based on index
378 * @np: pointer to device node with the property
379 * @list: pointer to a list with the elements
380 * @index: entry within the list of elements
381 * @nr_cells: number of cells in the list
382 * @nr_elem: number of elements for each entry in the list
383 * @out_args: returned values
384 *
385 * Populates the of_phandle_args based on the index in the list.
386 */
387static int pinctrl_copy_args(const struct device_node *np,
388 const __be32 *list,
389 int index, int nr_cells, int nr_elem,
390 struct of_phandle_args *out_args)
391{
392 int i;
393
394 memset(out_args, 0, sizeof(*out_args));
395 out_args->np = (struct device_node *)np;
396 out_args->args_count = nr_cells + 1;
397
398 if (index >= nr_elem)
399 return -EINVAL;
400
401 list += index * (nr_cells + 1);
402
403 for (i = 0; i < nr_cells + 1; i++)
404 out_args->args[i] = be32_to_cpup(list++);
405
406 return 0;
407}
408
409/**
410 * pinctrl_parse_index_with_args - Find a node pointed by index in a list
411 * @np: pointer to device node with the property
412 * @list_name: property that contains the list
413 * @index: index within the list
414 * @out_args: entries in the list pointed by index
415 *
416 * Finds the selected element in a pinctrl array consisting of an index
417 * within the controller and a number of u32 entries specified for each
418 * entry. Note that device_node is always for the parent pin controller device.
419 */
420int pinctrl_parse_index_with_args(const struct device_node *np,
421 const char *list_name, int index,
422 struct of_phandle_args *out_args)
423{
424 const __be32 *list;
425 int nr_elem, nr_cells, error;
426
427 error = pinctrl_get_list_and_count(np, list_name, &list,
428 &nr_cells, &nr_elem);
429 if (error || !nr_cells)
430 return error;
431
432 error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
433 out_args);
434 if (error)
435 return error;
436
437 return 0;
438}
439EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);