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