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(x: 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(objp: 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(map: dt_map->map);
56 list_del(entry: &dt_map->node);
57 dt_free_map(pctldev: dt_map->pctldev, map: dt_map->map,
58 num_maps: dt_map->num_maps);
59 kfree(objp: dt_map);
60 }
61
62 of_node_put(node: 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(s: dev_name(dev: 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(dev: pctldev->dev);
84 }
85
86 /* Remember the converted mapping table entries */
87 dt_map = kzalloc(size: 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(new: &dt_map->node, head: &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(node: np_config);
124 for (;;) {
125 if (!allow_default)
126 allow_default = of_property_read_bool(np: np_pctldev,
127 propname: "pinctrl-use-default");
128
129 np_pctldev = of_get_next_parent(node: np_pctldev);
130 if (!np_pctldev || of_node_is_root(node: np_pctldev)) {
131 of_node_put(node: np_pctldev);
132 ret = -ENODEV;
133 /* keep deferring if modules are enabled */
134 if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret < 0)
135 ret = -EPROBE_DEFER;
136 return ret;
137 }
138 /* If we're creating a hog we can use the passed pctldev */
139 if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
140 pctldev = hog_pctldev;
141 break;
142 }
143 pctldev = get_pinctrl_dev_from_of_node(np: np_pctldev);
144 if (pctldev)
145 break;
146 /* Do not defer probing of hogs (circular loop) */
147 if (np_pctldev == p->dev->of_node) {
148 of_node_put(node: np_pctldev);
149 return -ENODEV;
150 }
151 }
152 of_node_put(node: np_pctldev);
153
154 /*
155 * Call pinctrl driver to parse device tree node, and
156 * generate mapping table entries
157 */
158 ops = pctldev->desc->pctlops;
159 if (!ops->dt_node_to_map) {
160 dev_err(p->dev, "pctldev %s doesn't support DT\n",
161 dev_name(pctldev->dev));
162 return -ENODEV;
163 }
164 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
165 if (ret < 0)
166 return ret;
167 else if (num_maps == 0) {
168 /*
169 * If we have no valid maps (maybe caused by empty pinctrl node
170 * or typing error) ther is no need remember this, so just
171 * return.
172 */
173 dev_info(p->dev,
174 "there is not valid maps for state %s\n", statename);
175 return 0;
176 }
177
178 /* Stash the mapping table chunk away for later use */
179 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
180}
181
182static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
183{
184 struct pinctrl_map *map;
185
186 map = kzalloc(size: sizeof(*map), GFP_KERNEL);
187 if (!map)
188 return -ENOMEM;
189
190 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
191 map->type = PIN_MAP_TYPE_DUMMY_STATE;
192
193 return dt_remember_or_free_map(p, statename, NULL, map, num_maps: 1);
194}
195
196int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
197{
198 struct device_node *np = p->dev->of_node;
199 int state, ret;
200 char *propname;
201 struct property *prop;
202 const char *statename;
203 const __be32 *list;
204 int size, config;
205 phandle phandle;
206 struct device_node *np_config;
207
208 /* CONFIG_OF enabled, p->dev not instantiated from DT */
209 if (!np) {
210 if (of_have_populated_dt())
211 dev_dbg(p->dev,
212 "no of_node; not parsing pinctrl DT\n");
213 return 0;
214 }
215
216 /* We may store pointers to property names within the node */
217 of_node_get(node: np);
218
219 /* For each defined state ID */
220 for (state = 0; ; state++) {
221 /* Retrieve the pinctrl-* property */
222 propname = kasprintf(GFP_KERNEL, fmt: "pinctrl-%d", state);
223 if (!propname)
224 return -ENOMEM;
225 prop = of_find_property(np, name: propname, lenp: &size);
226 kfree(objp: propname);
227 if (!prop) {
228 if (state == 0) {
229 of_node_put(node: np);
230 return -ENODEV;
231 }
232 break;
233 }
234 list = prop->value;
235 size /= sizeof(*list);
236
237 /* Determine whether pinctrl-names property names the state */
238 ret = of_property_read_string_index(np, propname: "pinctrl-names",
239 index: state, output: &statename);
240 /*
241 * If not, statename is just the integer state ID. But rather
242 * than dynamically allocate it and have to free it later,
243 * just point part way into the property name for the string.
244 */
245 if (ret < 0)
246 statename = prop->name + strlen("pinctrl-");
247
248 /* For every referenced pin configuration node in it */
249 for (config = 0; config < size; config++) {
250 phandle = be32_to_cpup(p: list++);
251
252 /* Look up the pin configuration node */
253 np_config = of_find_node_by_phandle(handle: phandle);
254 if (!np_config) {
255 dev_err(p->dev,
256 "prop %s index %i invalid phandle\n",
257 prop->name, config);
258 ret = -EINVAL;
259 goto err;
260 }
261
262 /* Parse the node */
263 ret = dt_to_map_one_config(p, hog_pctldev: pctldev, statename,
264 np_config);
265 of_node_put(node: np_config);
266 if (ret < 0)
267 goto err;
268 }
269
270 /* No entries in DT? Generate a dummy state table entry */
271 if (!size) {
272 ret = dt_remember_dummy_state(p, statename);
273 if (ret < 0)
274 goto err;
275 }
276 }
277
278 return 0;
279
280err:
281 pinctrl_dt_free_maps(p);
282 return ret;
283}
284
285/*
286 * For pinctrl binding, typically #pinctrl-cells is for the pin controller
287 * device, so either parent or grandparent. See pinctrl-bindings.txt.
288 */
289static int pinctrl_find_cells_size(const struct device_node *np)
290{
291 const char *cells_name = "#pinctrl-cells";
292 int cells_size, error;
293
294 error = of_property_read_u32(np: np->parent, propname: cells_name, out_value: &cells_size);
295 if (error) {
296 error = of_property_read_u32(np: np->parent->parent,
297 propname: cells_name, out_value: &cells_size);
298 if (error)
299 return -ENOENT;
300 }
301
302 return cells_size;
303}
304
305/**
306 * pinctrl_get_list_and_count - Gets the list and it's cell size and number
307 * @np: pointer to device node with the property
308 * @list_name: property that contains the list
309 * @list: pointer for the list found
310 * @cells_size: pointer for the cell size found
311 * @nr_elements: pointer for the number of elements found
312 *
313 * Typically np is a single pinctrl entry containing the list.
314 */
315static int pinctrl_get_list_and_count(const struct device_node *np,
316 const char *list_name,
317 const __be32 **list,
318 int *cells_size,
319 int *nr_elements)
320{
321 int size;
322
323 *cells_size = 0;
324 *nr_elements = 0;
325
326 *list = of_get_property(node: np, name: list_name, lenp: &size);
327 if (!*list)
328 return -ENOENT;
329
330 *cells_size = pinctrl_find_cells_size(np);
331 if (*cells_size < 0)
332 return -ENOENT;
333
334 /* First element is always the index within the pinctrl device */
335 *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
336
337 return 0;
338}
339
340/**
341 * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
342 * @np: pointer to device node with the property
343 * @list_name: property that contains the list
344 *
345 * Counts the number of elements in a pinctrl array consisting of an index
346 * within the controller and a number of u32 entries specified for each
347 * entry. Note that device_node is always for the parent pin controller device.
348 */
349int pinctrl_count_index_with_args(const struct device_node *np,
350 const char *list_name)
351{
352 const __be32 *list;
353 int size, nr_cells, error;
354
355 error = pinctrl_get_list_and_count(np, list_name, list: &list,
356 cells_size: &nr_cells, nr_elements: &size);
357 if (error)
358 return error;
359
360 return size;
361}
362EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
363
364/**
365 * pinctrl_copy_args - Populates of_phandle_args based on index
366 * @np: pointer to device node with the property
367 * @list: pointer to a list with the elements
368 * @index: entry within the list of elements
369 * @nr_cells: number of cells in the list
370 * @nr_elem: number of elements for each entry in the list
371 * @out_args: returned values
372 *
373 * Populates the of_phandle_args based on the index in the list.
374 */
375static int pinctrl_copy_args(const struct device_node *np,
376 const __be32 *list,
377 int index, int nr_cells, int nr_elem,
378 struct of_phandle_args *out_args)
379{
380 int i;
381
382 memset(out_args, 0, sizeof(*out_args));
383 out_args->np = (struct device_node *)np;
384 out_args->args_count = nr_cells + 1;
385
386 if (index >= nr_elem)
387 return -EINVAL;
388
389 list += index * (nr_cells + 1);
390
391 for (i = 0; i < nr_cells + 1; i++)
392 out_args->args[i] = be32_to_cpup(p: list++);
393
394 return 0;
395}
396
397/**
398 * pinctrl_parse_index_with_args - Find a node pointed by index in a list
399 * @np: pointer to device node with the property
400 * @list_name: property that contains the list
401 * @index: index within the list
402 * @out_args: entries in the list pointed by index
403 *
404 * Finds the selected element in a pinctrl array consisting of an index
405 * within the controller and a number of u32 entries specified for each
406 * entry. Note that device_node is always for the parent pin controller device.
407 */
408int pinctrl_parse_index_with_args(const struct device_node *np,
409 const char *list_name, int index,
410 struct of_phandle_args *out_args)
411{
412 const __be32 *list;
413 int nr_elem, nr_cells, error;
414
415 error = pinctrl_get_list_and_count(np, list_name, list: &list,
416 cells_size: &nr_cells, nr_elements: &nr_elem);
417 if (error || !nr_cells)
418 return error;
419
420 error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
421 out_args);
422 if (error)
423 return error;
424
425 return 0;
426}
427EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);
428

source code of linux/drivers/pinctrl/devicetree.c