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  * @maps: the mapping table entries
  21  */
  22 struct pinctrl_dt_map {
  23         struct list_head node;
  24         struct pinctrl_dev *pctldev;
  25         struct pinctrl_map *map;
  26         unsigned num_maps;
  27 };
  28
  29 static void dt_free_map(struct pinctrl_dev *pctldev,
  30                      struct pinctrl_map *map, unsigned num_maps)
  31 {
  32         int i;
  33
  34         for (i = 0; i < num_maps; ++i) {
  35                 kfree_const(map[i].dev_name);
  36                 map[i].dev_name = NULL;
  37         }
  38
  39         if (pctldev) {
  40                 const struct pinctrl_ops *ops = pctldev->desc->pctlops;
  41                 if (ops->dt_free_map)
  42                         ops->dt_free_map(pctldev, map, num_maps);
  43         } else {
  44                 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
  45                 kfree(map);
  46         }
  47 }
  48
  49 void pinctrl_dt_free_maps(struct pinctrl *p)
  50 {
  51         struct pinctrl_dt_map *dt_map, *n1;
  52
  53         list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
  54                 pinctrl_unregister_mappings(dt_map->map);
  55                 list_del(&dt_map->node);
  56                 dt_free_map(dt_map->pctldev, dt_map->map,
  57                             dt_map->num_maps);
  58                 kfree(dt_map);
  59         }
  60
  61         of_node_put(p->dev->of_node);
  62 }
  63
  64 static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
  65                                    struct pinctrl_dev *pctldev,
  66                                    struct pinctrl_map *map, unsigned num_maps)
  67 {
  68         int i;
  69         struct pinctrl_dt_map *dt_map;
  70
  71         /* Initialize common mapping table entry fields */
  72         for (i = 0; i < num_maps; i++) {
  73                 const char *devname;
  74
  75                 devname = kstrdup_const(dev_name(p->dev), GFP_KERNEL);
  76                 if (!devname)
  77                         goto err_free_map;
  78
  79                 map[i].dev_name = devname;
  80                 map[i].name = statename;
  81                 if (pctldev)
  82                         map[i].ctrl_dev_name = dev_name(pctldev->dev);
  83         }
  84
  85         /* Remember the converted mapping table entries */
  86         dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
  87         if (!dt_map)
  88                 goto err_free_map;
  89
  90         dt_map->pctldev = pctldev;
  91         dt_map->map = map;
  92         dt_map->num_maps = num_maps;
  93         list_add_tail(&dt_map->node, &p->dt_maps);
  94
  95         return pinctrl_register_mappings(map, num_maps);
  96
  97 err_free_map:
  98         dt_free_map(pctldev, map, num_maps);
  99         return -ENOMEM;
 100 }
 101
 102 struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
 103 {
 104         return get_pinctrl_dev_from_of_node(np);
 105 }
 106
 107 static int dt_to_map_one_config(struct pinctrl *p,
 108                                 struct pinctrl_dev *hog_pctldev,
 109                                 const char *statename,
 110                                 struct device_node *np_config)
 111 {
 112         struct pinctrl_dev *pctldev = NULL;
 113         struct device_node *np_pctldev;
 114         const struct pinctrl_ops *ops;
 115         int ret;
 116         struct pinctrl_map *map;
 117         unsigned num_maps;
 118         bool allow_default = false;
 119
 120         /* Find the pin controller containing np_config */
 121         np_pctldev = of_node_get(np_config);
 122         for (;;) {
 123                 if (!allow_default)
 124                         allow_default = of_property_read_bool(np_pctldev,
 125                                                               "pinctrl-use-default");
 126
 127                 np_pctldev = of_get_next_parent(np_pctldev);
 128                 if (!np_pctldev || of_node_is_root(np_pctldev)) {
 129                         of_node_put(np_pctldev);
 130                         /* keep deferring if modules are enabled unless we've timed out */
 131                         if (IS_ENABLED(CONFIG_MODULES) && !allow_default)
 132                                 return driver_deferred_probe_check_state_continue(p->dev);
 133
 134                         return driver_deferred_probe_check_state(p->dev);
 135                 }
 136                 /* If we're creating a hog we can use the passed pctldev */
 137                 if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
 138                         pctldev = hog_pctldev;
 139                         break;
 140                 }
 141                 pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
 142                 if (pctldev)
 143                         break;
 144                 /* Do not defer probing of hogs (circular loop) */
 145                 if (np_pctldev == p->dev->of_node) {
 146                         of_node_put(np_pctldev);
 147                         return -ENODEV;
 148                 }
 149         }
 150         of_node_put(np_pctldev);
 151
 152         /*
 153          * Call pinctrl driver to parse device tree node, and
 154          * generate mapping table entries
 155          */
 156         ops = pctldev->desc->pctlops;
 157         if (!ops->dt_node_to_map) {
 158                 dev_err(p->dev, "pctldev %s doesn't support DT\n",
 159                         dev_name(pctldev->dev));
 160                 return -ENODEV;
 161         }
 162         ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
 163         if (ret < 0)
 164                 return ret;
 165         else if (num_maps == 0) {
 166                 /*
 167                  * If we have no valid maps (maybe caused by empty pinctrl node
 168                  * or typing error) ther is no need remember this, so just
 169                  * return.
 170                  */
 171                 dev_info(p->dev,
 172                          "there is not valid maps for state %s\n", statename);
 173                 return 0;
 174         }
 175
 176         /* Stash the mapping table chunk away for later use */
 177         return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
 178 }
 179
 180 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
 181 {
 182         struct pinctrl_map *map;
 183
 184         map = kzalloc(sizeof(*map), GFP_KERNEL);
 185         if (!map)
 186                 return -ENOMEM;
 187
 188         /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
 189         map->type = PIN_MAP_TYPE_DUMMY_STATE;
 190
 191         return dt_remember_or_free_map(p, statename, NULL, map, 1);
 192 }
 193
 194 int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
 195 {
 196         struct device_node *np = p->dev->of_node;
 197         int state, ret;
 198         char *propname;
 199         struct property *prop;
 200         const char *statename;
 201         const __be32 *list;
 202         int size, config;
 203         phandle phandle;
 204         struct device_node *np_config;
 205
 206         /* CONFIG_OF enabled, p->dev not instantiated from DT */
 207         if (!np) {
 208                 if (of_have_populated_dt())
 209                         dev_dbg(p->dev,
 210                                 "no of_node; not parsing pinctrl DT\n");
 211                 return 0;
 212         }
 213
 214         /* We may store pointers to property names within the node */
 215         of_node_get(np);
 216
 217         /* For each defined state ID */
 218         for (state = 0; ; state++) {
 219                 /* Retrieve the pinctrl-* property */
 220                 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
 221                 prop = of_find_property(np, propname, &size);
 222                 kfree(propname);
 223                 if (!prop) {
 224                         if (state == 0) {
 225                                 of_node_put(np);
 226                                 return -ENODEV;
 227                         }
 228                         break;
 229                 }
 230                 list = prop->value;
 231                 size /= sizeof(*list);
 232
 233                 /* Determine whether pinctrl-names property names the state */
 234                 ret = of_property_read_string_index(np, "pinctrl-names",
 235                                                     state, &statename);
 236                 /*
 237                  * If not, statename is just the integer state ID. But rather
 238                  * than dynamically allocate it and have to free it later,
 239                  * just point part way into the property name for the string.
 240                  */
 241                 if (ret < 0)
 242                         statename = prop->name + strlen("pinctrl-");
 243
 244                 /* For every referenced pin configuration node in it */
 245                 for (config = 0; config < size; config++) {
 246                         phandle = be32_to_cpup(list++);
 247
 248                         /* Look up the pin configuration node */
 249                         np_config = of_find_node_by_phandle(phandle);
 250                         if (!np_config) {
 251                                 dev_err(p->dev,
 252                                         "prop %s index %i invalid phandle\n",
 253                                         prop->name, config);
 254                                 ret = -EINVAL;
 255                                 goto err;
 256                         }
 257
 258                         /* Parse the node */
 259                         ret = dt_to_map_one_config(p, pctldev, statename,
 260                                                    np_config);
 261                         of_node_put(np_config);
 262                         if (ret < 0)
 263                                 goto err;
 264                 }
 265
 266                 /* No entries in DT? Generate a dummy state table entry */
 267                 if (!size) {
 268                         ret = dt_remember_dummy_state(p, statename);
 269                         if (ret < 0)
 270                                 goto err;
 271                 }
 272         }
 273
 274         return 0;
 275
 276 err:
 277         pinctrl_dt_free_maps(p);
 278         return ret;
 279 }
 280
 281 /*
 282  * For pinctrl binding, typically #pinctrl-cells is for the pin controller
 283  * device, so either parent or grandparent. See pinctrl-bindings.txt.
 284  */
 285 static int pinctrl_find_cells_size(const struct device_node *np)
 286 {
 287         const char *cells_name = "#pinctrl-cells";
 288         int cells_size, error;
 289
 290         error = of_property_read_u32(np->parent, cells_name, &cells_size);
 291         if (error) {
 292                 error = of_property_read_u32(np->parent->parent,
 293                                              cells_name, &cells_size);
 294                 if (error)
 295                         return -ENOENT;
 296         }
 297
 298         return cells_size;
 299 }
 300
 301 /**
 302  * pinctrl_get_list_and_count - Gets the list and it's cell size and number
 303  * @np: pointer to device node with the property
 304  * @list_name: property that contains the list
 305  * @list: pointer for the list found
 306  * @cells_size: pointer for the cell size found
 307  * @nr_elements: pointer for the number of elements found
 308  *
 309  * Typically np is a single pinctrl entry containing the list.
 310  */
 311 static int pinctrl_get_list_and_count(const struct device_node *np,
 312                                       const char *list_name,
 313                                       const __be32 **list,
 314                                       int *cells_size,
 315                                       int *nr_elements)
 316 {
 317         int size;
 318
 319         *cells_size = 0;
 320         *nr_elements = 0;
 321
 322         *list = of_get_property(np, list_name, &size);
 323         if (!*list)
 324                 return -ENOENT;
 325
 326         *cells_size = pinctrl_find_cells_size(np);
 327         if (*cells_size < 0)
 328                 return -ENOENT;
 329
 330         /* First element is always the index within the pinctrl device */
 331         *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
 332
 333         return 0;
 334 }
 335
 336 /**
 337  * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
 338  * @np: pointer to device node with the property
 339  * @list_name: property that contains the list
 340  *
 341  * Counts the number of elements in a pinctrl array consisting of an index
 342  * within the controller and a number of u32 entries specified for each
 343  * entry. Note that device_node is always for the parent pin controller device.
 344  */
 345 int pinctrl_count_index_with_args(const struct device_node *np,
 346                                   const char *list_name)
 347 {
 348         const __be32 *list;
 349         int size, nr_cells, error;
 350
 351         error = pinctrl_get_list_and_count(np, list_name, &list,
 352                                            &nr_cells, &size);
 353         if (error)
 354                 return error;
 355
 356         return size;
 357 }
 358 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
 359
 360 /**
 361  * pinctrl_copy_args - Populates of_phandle_args based on index
 362  * @np: pointer to device node with the property
 363  * @list: pointer to a list with the elements
 364  * @index: entry within the list of elements
 365  * @nr_cells: number of cells in the list
 366  * @nr_elem: number of elements for each entry in the list
 367  * @out_args: returned values
 368  *
 369  * Populates the of_phandle_args based on the index in the list.
 370  */
 371 static int pinctrl_copy_args(const struct device_node *np,
 372                              const __be32 *list,
 373                              int index, int nr_cells, int nr_elem,
 374                              struct of_phandle_args *out_args)
 375 {
 376         int i;
 377
 378         memset(out_args, 0, sizeof(*out_args));
 379         out_args->np = (struct device_node *)np;
 380         out_args->args_count = nr_cells + 1;
 381
 382         if (index >= nr_elem)
 383                 return -EINVAL;
 384
 385         list += index * (nr_cells + 1);
 386
 387         for (i = 0; i < nr_cells + 1; i++)
 388                 out_args->args[i] = be32_to_cpup(list++);
 389
 390         return 0;
 391 }
 392
 393 /**
 394  * pinctrl_parse_index_with_args - Find a node pointed by index in a list
 395  * @np: pointer to device node with the property
 396  * @list_name: property that contains the list
 397  * @index: index within the list
 398  * @out_arts: entries in the list pointed by index
 399  *
 400  * Finds the selected element in a pinctrl array consisting of an index
 401  * within the controller and a number of u32 entries specified for each
 402  * entry. Note that device_node is always for the parent pin controller device.
 403  */
 404 int pinctrl_parse_index_with_args(const struct device_node *np,
 405                                   const char *list_name, int index,
 406                                   struct of_phandle_args *out_args)
 407 {
 408         const __be32 *list;
 409         int nr_elem, nr_cells, error;
 410
 411         error = pinctrl_get_list_and_count(np, list_name, &list,
 412                                            &nr_cells, &nr_elem);
 413         if (error || !nr_cells)
 414                 return error;
 415
 416         error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
 417                                   out_args);
 418         if (error)
 419                 return error;
 420
 421         return 0;
 422 }
 423 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);