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 num_maps;
  28 };
  29
  30 static 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
  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 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 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 */
 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                 prop = of_find_property(np, propname, &size);
 224                 kfree(propname);
 225                 if (!prop) {
 226                         if (state == 0) {
 227                                 of_node_put(np);
 228                                 return -ENODEV;
 229                         }
 230                         break;
 231                 }
 232                 list = prop->value;
 233                 size /= sizeof(*list);
 234
 235                 /* Determine whether pinctrl-names property names the state */
 236                 ret = of_property_read_string_index(np, "pinctrl-names",
 237                                                     state, &statename);
 238                 /*
 239                  * If not, statename is just the integer state ID. But rather
 240                  * than dynamically allocate it and have to free it later,
 241                  * just point part way into the property name for the string.
 242                  */
 243                 if (ret < 0)
 244                         statename = prop->name + strlen("pinctrl-");
 245
 246                 /* For every referenced pin configuration node in it */
 247                 for (config = 0; config < size; config++) {
 248                         phandle = be32_to_cpup(list++);
 249
 250                         /* Look up the pin configuration node */
 251                         np_config = of_find_node_by_phandle(phandle);
 252                         if (!np_config) {
 253                                 dev_err(p->dev,
 254                                         "prop %s index %i invalid phandle\n",
 255                                         prop->name, config);
 256                                 ret = -EINVAL;
 257                                 goto err;
 258                         }
 259
 260                         /* Parse the node */
 261                         ret = dt_to_map_one_config(p, pctldev, statename,
 262                                                    np_config);
 263                         of_node_put(np_config);
 264                         if (ret < 0)
 265                                 goto err;
 266                 }
 267
 268                 /* No entries in DT? Generate a dummy state table entry */
 269                 if (!size) {
 270                         ret = dt_remember_dummy_state(p, statename);
 271                         if (ret < 0)
 272                                 goto err;
 273                 }
 274         }
 275
 276         return 0;
 277
 278 err:
 279         pinctrl_dt_free_maps(p);
 280         return ret;
 281 }
 282
 283 /*
 284  * For pinctrl binding, typically #pinctrl-cells is for the pin controller
 285  * device, so either parent or grandparent. See pinctrl-bindings.txt.
 286  */
 287 static int pinctrl_find_cells_size(const struct device_node *np)
 288 {
 289         const char *cells_name = "#pinctrl-cells";
 290         int cells_size, error;
 291
 292         error = of_property_read_u32(np->parent, cells_name, &cells_size);
 293         if (error) {
 294                 error = of_property_read_u32(np->parent->parent,
 295                                              cells_name, &cells_size);
 296                 if (error)
 297                         return -ENOENT;
 298         }
 299
 300         return cells_size;
 301 }
 302
 303 /**
 304  * pinctrl_get_list_and_count - Gets the list and it's cell size and number
 305  * @np: pointer to device node with the property
 306  * @list_name: property that contains the list
 307  * @list: pointer for the list found
 308  * @cells_size: pointer for the cell size found
 309  * @nr_elements: pointer for the number of elements found
 310  *
 311  * Typically np is a single pinctrl entry containing the list.
 312  */
 313 static int pinctrl_get_list_and_count(const struct device_node *np,
 314                                       const char *list_name,
 315                                       const __be32 **list,
 316                                       int *cells_size,
 317                                       int *nr_elements)
 318 {
 319         int size;
 320
 321         *cells_size = 0;
 322         *nr_elements = 0;
 323
 324         *list = of_get_property(np, list_name, &size);
 325         if (!*list)
 326                 return -ENOENT;
 327
 328         *cells_size = pinctrl_find_cells_size(np);
 329         if (*cells_size < 0)
 330                 return -ENOENT;
 331
 332         /* First element is always the index within the pinctrl device */
 333         *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
 334
 335         return 0;
 336 }
 337
 338 /**
 339  * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
 340  * @np: pointer to device node with the property
 341  * @list_name: property that contains the list
 342  *
 343  * Counts the number of elements in a pinctrl array consisting of an index
 344  * within the controller and a number of u32 entries specified for each
 345  * entry. Note that device_node is always for the parent pin controller device.
 346  */
 347 int pinctrl_count_index_with_args(const struct device_node *np,
 348                                   const char *list_name)
 349 {
 350         const __be32 *list;
 351         int size, nr_cells, error;
 352
 353         error = pinctrl_get_list_and_count(np, list_name, &list,
 354                                            &nr_cells, &size);
 355         if (error)
 356                 return error;
 357
 358         return size;
 359 }
 360 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
 361
 362 /**
 363  * pinctrl_copy_args - Populates of_phandle_args based on index
 364  * @np: pointer to device node with the property
 365  * @list: pointer to a list with the elements
 366  * @index: entry within the list of elements
 367  * @nr_cells: number of cells in the list
 368  * @nr_elem: number of elements for each entry in the list
 369  * @out_args: returned values
 370  *
 371  * Populates the of_phandle_args based on the index in the list.
 372  */
 373 static int pinctrl_copy_args(const struct device_node *np,
 374                              const __be32 *list,
 375                              int index, int nr_cells, int nr_elem,
 376                              struct of_phandle_args *out_args)
 377 {
 378         int i;
 379
 380         memset(out_args, 0, sizeof(*out_args));
 381         out_args->np = (struct device_node *)np;
 382         out_args->args_count = nr_cells + 1;
 383
 384         if (index >= nr_elem)
 385                 return -EINVAL;
 386
 387         list += index * (nr_cells + 1);
 388
 389         for (i = 0; i < nr_cells + 1; i++)
 390                 out_args->args[i] = be32_to_cpup(list++);
 391
 392         return 0;
 393 }
 394
 395 /**
 396  * pinctrl_parse_index_with_args - Find a node pointed by index in a list
 397  * @np: pointer to device node with the property
 398  * @list_name: property that contains the list
 399  * @index: index within the list
 400  * @out_args: entries in the list pointed by index
 401  *
 402  * Finds the selected element in a pinctrl array consisting of an index
 403  * within the controller and a number of u32 entries specified for each
 404  * entry. Note that device_node is always for the parent pin controller device.
 405  */
 406 int pinctrl_parse_index_with_args(const struct device_node *np,
 407                                   const char *list_name, int index,
 408                                   struct of_phandle_args *out_args)
 409 {
 410         const __be32 *list;
 411         int nr_elem, nr_cells, error;
 412
 413         error = pinctrl_get_list_and_count(np, list_name, &list,
 414                                            &nr_cells, &nr_elem);
 415         if (error || !nr_cells)
 416                 return error;
 417
 418         error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
 419                                   out_args);
 420         if (error)
 421                 return error;
 422
 423         return 0;
 424 }
 425 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);