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