drivers/pinctrl/devicetree.c

   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  */
  23 struct 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
  30 static 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
  50 void 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
  65 static 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 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
  98 err_free_map:
  99         dt_free_map(pctldev, map, num_maps);
 100         return -ENOMEM;
 101 }
 102
 103 struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
 104 {
 105         return get_pinctrl_dev_from_of_node(np);
 106 }
 107 EXPORT_SYMBOL_GPL(of_pinctrl_get);
 108
 109 static 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 int 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 = -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_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(np_pctldev);
 149                         return -ENODEV;
 150                 }
 151         }
 152         of_node_put(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
 182 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
 183 {
 184         struct pinctrl_map *map;
 185
 186         map = kzalloc(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, 1);
 194 }
 195
 196 int 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(np);
 218
 219         /* For each defined state ID */
 220         for (state = 0; ; state++) {
 221                 /* Retrieve the pinctrl-* property */
 222                 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
 223                 if (!propname) {
 224                         ret = -ENOMEM;
 225                         goto err;
 226                 }
 227                 prop = of_find_property(np, propname, &size);
 228                 kfree(propname);
 229                 if (!prop) {
 230                         if (state == 0) {
 231                                 ret = -ENODEV;
 232                                 goto err;
 233                         }
 234                         break;
 235                 }
 236                 list = prop->value;
 237                 size /= sizeof(*list);
 238
 239                 /* Determine whether pinctrl-names property names the state */
 240                 ret = of_property_read_string_index(np, "pinctrl-names",
 241                                                     state, &statename);
 242                 /*
 243                  * If not, statename is just the integer state ID. But rather
 244                  * than dynamically allocate it and have to free it later,
 245                  * just point part way into the property name for the string.
 246                  */
 247                 if (ret < 0)
 248                         statename = prop->name + strlen("pinctrl-");
 249
 250                 /* For every referenced pin configuration node in it */
 251                 for (config = 0; config < size; config++) {
 252                         phandle = be32_to_cpup(list++);
 253
 254                         /* Look up the pin configuration node */
 255                         np_config = of_find_node_by_phandle(phandle);
 256                         if (!np_config) {
 257                                 dev_err(p->dev,
 258                                         "prop %s index %i invalid phandle\n",
 259                                         prop->name, config);
 260                                 ret = -EINVAL;
 261                                 goto err;
 262                         }
 263
 264                         /* Parse the node */
 265                         ret = dt_to_map_one_config(p, pctldev, statename,
 266                                                    np_config);
 267                         of_node_put(np_config);
 268                         if (ret < 0)
 269                                 goto err;
 270                 }
 271
 272                 /* No entries in DT? Generate a dummy state table entry */
 273                 if (!size) {
 274                         ret = dt_remember_dummy_state(p, statename);
 275                         if (ret < 0)
 276                                 goto err;
 277                 }
 278         }
 279
 280         return 0;
 281
 282 err:
 283         pinctrl_dt_free_maps(p);
 284         return ret;
 285 }
 286
 287 /*
 288  * For pinctrl binding, typically #pinctrl-cells is for the pin controller
 289  * device, so either parent or grandparent. See pinctrl-bindings.txt.
 290  */
 291 static int pinctrl_find_cells_size(const struct device_node *np)
 292 {
 293         const char *cells_name = "#pinctrl-cells";
 294         int cells_size, error;
 295
 296         error = of_property_read_u32(np->parent, cells_name, &cells_size);
 297         if (error) {
 298                 error = of_property_read_u32(np->parent->parent,
 299                                              cells_name, &cells_size);
 300                 if (error)
 301                         return -ENOENT;
 302         }
 303
 304         return cells_size;
 305 }
 306
 307 /**
 308  * pinctrl_get_list_and_count - Gets the list and it's cell size and number
 309  * @np: pointer to device node with the property
 310  * @list_name: property that contains the list
 311  * @list: pointer for the list found
 312  * @cells_size: pointer for the cell size found
 313  * @nr_elements: pointer for the number of elements found
 314  *
 315  * Typically np is a single pinctrl entry containing the list.
 316  */
 317 static int pinctrl_get_list_and_count(const struct device_node *np,
 318                                       const char *list_name,
 319                                       const __be32 **list,
 320                                       int *cells_size,
 321                                       int *nr_elements)
 322 {
 323         int size;
 324
 325         *cells_size = 0;
 326         *nr_elements = 0;
 327
 328         *list = of_get_property(np, list_name, &size);
 329         if (!*list)
 330                 return -ENOENT;
 331
 332         *cells_size = pinctrl_find_cells_size(np);
 333         if (*cells_size < 0)
 334                 return -ENOENT;
 335
 336         /* First element is always the index within the pinctrl device */
 337         *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
 338
 339         return 0;
 340 }
 341
 342 /**
 343  * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
 344  * @np: pointer to device node with the property
 345  * @list_name: property that contains the list
 346  *
 347  * Counts the number of elements in a pinctrl array consisting of an index
 348  * within the controller and a number of u32 entries specified for each
 349  * entry. Note that device_node is always for the parent pin controller device.
 350  */
 351 int pinctrl_count_index_with_args(const struct device_node *np,
 352                                   const char *list_name)
 353 {
 354         const __be32 *list;
 355         int size, nr_cells, error;
 356
 357         error = pinctrl_get_list_and_count(np, list_name, &list,
 358                                            &nr_cells, &size);
 359         if (error)
 360                 return error;
 361
 362         return size;
 363 }
 364 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
 365
 366 /**
 367  * pinctrl_copy_args - Populates of_phandle_args based on index
 368  * @np: pointer to device node with the property
 369  * @list: pointer to a list with the elements
 370  * @index: entry within the list of elements
 371  * @nr_cells: number of cells in the list
 372  * @nr_elem: number of elements for each entry in the list
 373  * @out_args: returned values
 374  *
 375  * Populates the of_phandle_args based on the index in the list.
 376  */
 377 static int pinctrl_copy_args(const struct device_node *np,
 378                              const __be32 *list,
 379                              int index, int nr_cells, int nr_elem,
 380                              struct of_phandle_args *out_args)
 381 {
 382         int i;
 383
 384         memset(out_args, 0, sizeof(*out_args));
 385         out_args->np = (struct device_node *)np;
 386         out_args->args_count = nr_cells + 1;
 387
 388         if (index >= nr_elem)
 389                 return -EINVAL;
 390
 391         list += index * (nr_cells + 1);
 392
 393         for (i = 0; i < nr_cells + 1; i++)
 394                 out_args->args[i] = be32_to_cpup(list++);
 395
 396         return 0;
 397 }
 398
 399 /**
 400  * pinctrl_parse_index_with_args - Find a node pointed by index in a list
 401  * @np: pointer to device node with the property
 402  * @list_name: property that contains the list
 403  * @index: index within the list
 404  * @out_args: entries in the list pointed by index
 405  *
 406  * Finds the selected element in a pinctrl array consisting of an index
 407  * within the controller and a number of u32 entries specified for each
 408  * entry. Note that device_node is always for the parent pin controller device.
 409  */
 410 int pinctrl_parse_index_with_args(const struct device_node *np,
 411                                   const char *list_name, int index,
 412                                   struct of_phandle_args *out_args)
 413 {
 414         const __be32 *list;
 415         int nr_elem, nr_cells, error;
 416
 417         error = pinctrl_get_list_and_count(np, list_name, &list,
 418                                            &nr_cells, &nr_elem);
 419         if (error || !nr_cells)
 420                 return error;
 421
 422         error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
 423                                   out_args);
 424         if (error)
 425                 return error;
 426
 427         return 0;
 428 }
 429 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);