drivers/pinctrl/devicetree.c

   1 /*
   2  * Device tree integration for the pin control subsystem
   3  *
   4  * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <linux/device.h>
  20 #include <linux/of.h>
  21 #include <linux/pinctrl/pinctrl.h>
  22 #include <linux/slab.h>
  23
  24 #include "core.h"
  25 #include "devicetree.h"
  26
  27 /**
  28  * struct pinctrl_dt_map - mapping table chunk parsed from device tree
  29  * @node: list node for struct pinctrl's @dt_maps field
  30  * @pctldev: the pin controller that allocated this struct, and will free it
  31  * @maps: the mapping table entries
  32  */
  33 struct pinctrl_dt_map {
  34         struct list_head node;
  35         struct pinctrl_dev *pctldev;
  36         struct pinctrl_map *map;
  37         unsigned num_maps;
  38 };
  39
  40 static void dt_free_map(struct pinctrl_dev *pctldev,
  41                      struct pinctrl_map *map, unsigned num_maps)
  42 {
  43         if (pctldev) {
  44                 const struct pinctrl_ops *ops = pctldev->desc->pctlops;
  45                 if (ops->dt_free_map)
  46                         ops->dt_free_map(pctldev, map, num_maps);
  47         } else {
  48                 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
  49                 kfree(map);
  50         }
  51 }
  52
  53 void pinctrl_dt_free_maps(struct pinctrl *p)
  54 {
  55         struct pinctrl_dt_map *dt_map, *n1;
  56
  57         list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
  58                 pinctrl_unregister_map(dt_map->map);
  59                 list_del(&dt_map->node);
  60                 dt_free_map(dt_map->pctldev, dt_map->map,
  61                             dt_map->num_maps);
  62                 kfree(dt_map);
  63         }
  64
  65         of_node_put(p->dev->of_node);
  66 }
  67
  68 static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
  69                                    struct pinctrl_dev *pctldev,
  70                                    struct pinctrl_map *map, unsigned num_maps)
  71 {
  72         int i;
  73         struct pinctrl_dt_map *dt_map;
  74
  75         /* Initialize common mapping table entry fields */
  76         for (i = 0; i < num_maps; i++) {
  77                 map[i].dev_name = dev_name(p->dev);
  78                 map[i].name = statename;
  79                 if (pctldev)
  80                         map[i].ctrl_dev_name = dev_name(pctldev->dev);
  81         }
  82
  83         /* Remember the converted mapping table entries */
  84         dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
  85         if (!dt_map) {
  86                 dt_free_map(pctldev, map, num_maps);
  87                 return -ENOMEM;
  88         }
  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_map(map, num_maps, false);
  96 }
  97
  98 struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
  99 {
 100         return get_pinctrl_dev_from_of_node(np);
 101 }
 102
 103 static int dt_to_map_one_config(struct pinctrl *p,
 104                                 struct pinctrl_dev *hog_pctldev,
 105                                 const char *statename,
 106                                 struct device_node *np_config)
 107 {
 108         struct pinctrl_dev *pctldev = NULL;
 109         struct device_node *np_pctldev;
 110         const struct pinctrl_ops *ops;
 111         int ret;
 112         struct pinctrl_map *map;
 113         unsigned num_maps;
 114         bool allow_default = false;
 115
 116         /* Find the pin controller containing np_config */
 117         np_pctldev = of_node_get(np_config);
 118         for (;;) {
 119                 if (!allow_default)
 120                         allow_default = of_property_read_bool(np_pctldev,
 121                                                               "pinctrl-use-default");
 122
 123                 np_pctldev = of_get_next_parent(np_pctldev);
 124                 if (!np_pctldev || of_node_is_root(np_pctldev)) {
 125                         of_node_put(np_pctldev);
 126                         ret = driver_deferred_probe_check_state(p->dev);
 127                         /* keep deferring if modules are enabled unless we've timed out */
 128                         if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret == -ENODEV)
 129                                 ret = -EPROBE_DEFER;
 130
 131                         return ret;
 132                 }
 133                 /* If we're creating a hog we can use the passed pctldev */
 134                 if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
 135                         pctldev = hog_pctldev;
 136                         break;
 137                 }
 138                 pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
 139                 if (pctldev)
 140                         break;
 141                 /* Do not defer probing of hogs (circular loop) */
 142                 if (np_pctldev == p->dev->of_node) {
 143                         of_node_put(np_pctldev);
 144                         return -ENODEV;
 145                 }
 146         }
 147         of_node_put(np_pctldev);
 148
 149         /*
 150          * Call pinctrl driver to parse device tree node, and
 151          * generate mapping table entries
 152          */
 153         ops = pctldev->desc->pctlops;
 154         if (!ops->dt_node_to_map) {
 155                 dev_err(p->dev, "pctldev %s doesn't support DT\n",
 156                         dev_name(pctldev->dev));
 157                 return -ENODEV;
 158         }
 159         ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
 160         if (ret < 0)
 161                 return ret;
 162
 163         /* Stash the mapping table chunk away for later use */
 164         return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
 165 }
 166
 167 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
 168 {
 169         struct pinctrl_map *map;
 170
 171         map = kzalloc(sizeof(*map), GFP_KERNEL);
 172         if (!map)
 173                 return -ENOMEM;
 174
 175         /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
 176         map->type = PIN_MAP_TYPE_DUMMY_STATE;
 177
 178         return dt_remember_or_free_map(p, statename, NULL, map, 1);
 179 }
 180
 181 bool pinctrl_dt_has_hogs(struct pinctrl_dev *pctldev)
 182 {
 183         struct device_node *np;
 184         struct property *prop;
 185         int size;
 186
 187         np = pctldev->dev->of_node;
 188         if (!np)
 189                 return false;
 190
 191         prop = of_find_property(np, "pinctrl-0", &size);
 192
 193         return prop ? true : false;
 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                         /* strlen("pinctrl-") == 8 */
 245                         statename = prop->name + 8;
 246                 }
 247
 248                 /* For every referenced pin configuration node in it */
 249                 for (config = 0; config < size; config++) {
 250                         phandle = be32_to_cpup(list++);
 251
 252                         /* Look up the pin configuration node */
 253                         np_config = of_find_node_by_phandle(phandle);
 254                         if (!np_config) {
 255                                 dev_err(p->dev,
 256                                         "prop %s index %i invalid phandle\n",
 257                                         prop->name, config);
 258                                 ret = -EINVAL;
 259                                 goto err;
 260                         }
 261
 262                         /* Parse the node */
 263                         ret = dt_to_map_one_config(p, pctldev, statename,
 264                                                    np_config);
 265                         of_node_put(np_config);
 266                         if (ret < 0)
 267                                 goto err;
 268                 }
 269
 270                 /* No entries in DT? Generate a dummy state table entry */
 271                 if (!size) {
 272                         ret = dt_remember_dummy_state(p, statename);
 273                         if (ret < 0)
 274                                 goto err;
 275                 }
 276         }
 277
 278         return 0;
 279
 280 err:
 281         pinctrl_dt_free_maps(p);
 282         return ret;
 283 }
 284
 285 /*
 286  * For pinctrl binding, typically #pinctrl-cells is for the pin controller
 287  * device, so either parent or grandparent. See pinctrl-bindings.txt.
 288  */
 289 static int pinctrl_find_cells_size(const struct device_node *np)
 290 {
 291         const char *cells_name = "#pinctrl-cells";
 292         int cells_size, error;
 293
 294         error = of_property_read_u32(np->parent, cells_name, &cells_size);
 295         if (error) {
 296                 error = of_property_read_u32(np->parent->parent,
 297                                              cells_name, &cells_size);
 298                 if (error)
 299                         return -ENOENT;
 300         }
 301
 302         return cells_size;
 303 }
 304
 305 /**
 306  * pinctrl_get_list_and_count - Gets the list and it's cell size and number
 307  * @np: pointer to device node with the property
 308  * @list_name: property that contains the list
 309  * @list: pointer for the list found
 310  * @cells_size: pointer for the cell size found
 311  * @nr_elements: pointer for the number of elements found
 312  *
 313  * Typically np is a single pinctrl entry containing the list.
 314  */
 315 static int pinctrl_get_list_and_count(const struct device_node *np,
 316                                       const char *list_name,
 317                                       const __be32 **list,
 318                                       int *cells_size,
 319                                       int *nr_elements)
 320 {
 321         int size;
 322
 323         *cells_size = 0;
 324         *nr_elements = 0;
 325
 326         *list = of_get_property(np, list_name, &size);
 327         if (!*list)
 328                 return -ENOENT;
 329
 330         *cells_size = pinctrl_find_cells_size(np);
 331         if (*cells_size < 0)
 332                 return -ENOENT;
 333
 334         /* First element is always the index within the pinctrl device */
 335         *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
 336
 337         return 0;
 338 }
 339
 340 /**
 341  * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
 342  * @np: pointer to device node with the property
 343  * @list_name: property that contains the list
 344  *
 345  * Counts the number of elements in a pinctrl array consisting of an index
 346  * within the controller and a number of u32 entries specified for each
 347  * entry. Note that device_node is always for the parent pin controller device.
 348  */
 349 int pinctrl_count_index_with_args(const struct device_node *np,
 350                                   const char *list_name)
 351 {
 352         const __be32 *list;
 353         int size, nr_cells, error;
 354
 355         error = pinctrl_get_list_and_count(np, list_name, &list,
 356                                            &nr_cells, &size);
 357         if (error)
 358                 return error;
 359
 360         return size;
 361 }
 362 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
 363
 364 /**
 365  * pinctrl_copy_args - Populates of_phandle_args based on index
 366  * @np: pointer to device node with the property
 367  * @list: pointer to a list with the elements
 368  * @index: entry within the list of elements
 369  * @nr_cells: number of cells in the list
 370  * @nr_elem: number of elements for each entry in the list
 371  * @out_args: returned values
 372  *
 373  * Populates the of_phandle_args based on the index in the list.
 374  */
 375 static int pinctrl_copy_args(const struct device_node *np,
 376                              const __be32 *list,
 377                              int index, int nr_cells, int nr_elem,
 378                              struct of_phandle_args *out_args)
 379 {
 380         int i;
 381
 382         memset(out_args, 0, sizeof(*out_args));
 383         out_args->np = (struct device_node *)np;
 384         out_args->args_count = nr_cells + 1;
 385
 386         if (index >= nr_elem)
 387                 return -EINVAL;
 388
 389         list += index * (nr_cells + 1);
 390
 391         for (i = 0; i < nr_cells + 1; i++)
 392                 out_args->args[i] = be32_to_cpup(list++);
 393
 394         return 0;
 395 }
 396
 397 /**
 398  * pinctrl_parse_index_with_args - Find a node pointed by index in a list
 399  * @np: pointer to device node with the property
 400  * @list_name: property that contains the list
 401  * @index: index within the list
 402  * @out_arts: entries in the list pointed by index
 403  *
 404  * Finds the selected element in a pinctrl array consisting of an index
 405  * within the controller and a number of u32 entries specified for each
 406  * entry. Note that device_node is always for the parent pin controller device.
 407  */
 408 int pinctrl_parse_index_with_args(const struct device_node *np,
 409                                   const char *list_name, int index,
 410                                   struct of_phandle_args *out_args)
 411 {
 412         const __be32 *list;
 413         int nr_elem, nr_cells, error;
 414
 415         error = pinctrl_get_list_and_count(np, list_name, &list,
 416                                            &nr_cells, &nr_elem);
 417         if (error || !nr_cells)
 418                 return error;
 419
 420         error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
 421                                   out_args);
 422         if (error)
 423                 return error;
 424
 425         return 0;
 426 }
 427 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);