root/drivers/pinctrl/devicetree.c

DEFINITIONS

1. dt_free_map
2. pinctrl_dt_free_maps
3. dt_remember_or_free_map
4. of_pinctrl_get
5. dt_to_map_one_config
6. dt_remember_dummy_state
7. pinctrl_dt_has_hogs
8. pinctrl_dt_to_map
9. pinctrl_find_cells_size
10. pinctrl_get_list_and_count
11. pinctrl_count_index_with_args
12. pinctrl_copy_args
13. pinctrl_parse_index_with_args

   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_map(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_map(map, num_maps, false);
  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 
 166         /* Stash the mapping table chunk away for later use */
 167         return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
 168 }
 169 
 170 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
 171 {
 172         struct pinctrl_map *map;
 173 
 174         map = kzalloc(sizeof(*map), GFP_KERNEL);
 175         if (!map)
 176                 return -ENOMEM;
 177 
 178         /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
 179         map->type = PIN_MAP_TYPE_DUMMY_STATE;
 180 
 181         return dt_remember_or_free_map(p, statename, NULL, map, 1);
 182 }
 183 
 184 bool pinctrl_dt_has_hogs(struct pinctrl_dev *pctldev)
 185 {
 186         struct device_node *np;
 187         struct property *prop;
 188         int size;
 189 
 190         np = pctldev->dev->of_node;
 191         if (!np)
 192                 return false;
 193 
 194         prop = of_find_property(np, "pinctrl-0", &size);
 195 
 196         return prop ? true : false;
 197 }
 198 
 199 int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
 200 {
 201         struct device_node *np = p->dev->of_node;
 202         int state, ret;
 203         char *propname;
 204         struct property *prop;
 205         const char *statename;
 206         const __be32 *list;
 207         int size, config;
 208         phandle phandle;
 209         struct device_node *np_config;
 210 
 211         /* CONFIG_OF enabled, p->dev not instantiated from DT */
 212         if (!np) {
 213                 if (of_have_populated_dt())
 214                         dev_dbg(p->dev,
 215                                 "no of_node; not parsing pinctrl DT\n");
 216                 return 0;
 217         }
 218 
 219         /* We may store pointers to property names within the node */
 220         of_node_get(np);
 221 
 222         /* For each defined state ID */
 223         for (state = 0; ; state++) {
 224                 /* Retrieve the pinctrl-* property */
 225                 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
 226                 prop = of_find_property(np, propname, &size);
 227                 kfree(propname);
 228                 if (!prop) {
 229                         if (state == 0) {
 230                                 of_node_put(np);
 231                                 return -ENODEV;
 232                         }
 233                         break;
 234                 }
 235                 list = prop->value;
 236                 size /= sizeof(*list);
 237 
 238                 /* Determine whether pinctrl-names property names the state */
 239                 ret = of_property_read_string_index(np, "pinctrl-names",
 240                                                     state, &statename);
 241                 /*
 242                  * If not, statename is just the integer state ID. But rather
 243                  * than dynamically allocate it and have to free it later,
 244                  * just point part way into the property name for the string.
 245                  */
 246                 if (ret < 0)
 247                         statename = prop->name + strlen("pinctrl-");
 248 
 249                 /* For every referenced pin configuration node in it */
 250                 for (config = 0; config < size; config++) {
 251                         phandle = be32_to_cpup(list++);
 252 
 253                         /* Look up the pin configuration node */
 254                         np_config = of_find_node_by_phandle(phandle);
 255                         if (!np_config) {
 256                                 dev_err(p->dev,
 257                                         "prop %s index %i invalid phandle\n",
 258                                         prop->name, config);
 259                                 ret = -EINVAL;
 260                                 goto err;
 261                         }
 262 
 263                         /* Parse the node */
 264                         ret = dt_to_map_one_config(p, pctldev, statename,
 265                                                    np_config);
 266                         of_node_put(np_config);
 267                         if (ret < 0)
 268                                 goto err;
 269                 }
 270 
 271                 /* No entries in DT? Generate a dummy state table entry */
 272                 if (!size) {
 273                         ret = dt_remember_dummy_state(p, statename);
 274                         if (ret < 0)
 275                                 goto err;
 276                 }
 277         }
 278 
 279         return 0;
 280 
 281 err:
 282         pinctrl_dt_free_maps(p);
 283         return ret;
 284 }
 285 
 286 /*
 287  * For pinctrl binding, typically #pinctrl-cells is for the pin controller
 288  * device, so either parent or grandparent. See pinctrl-bindings.txt.
 289  */
 290 static int pinctrl_find_cells_size(const struct device_node *np)
 291 {
 292         const char *cells_name = "#pinctrl-cells";
 293         int cells_size, error;
 294 
 295         error = of_property_read_u32(np->parent, cells_name, &cells_size);
 296         if (error) {
 297                 error = of_property_read_u32(np->parent->parent,
 298                                              cells_name, &cells_size);
 299                 if (error)
 300                         return -ENOENT;
 301         }
 302 
 303         return cells_size;
 304 }
 305 
 306 /**
 307  * pinctrl_get_list_and_count - Gets the list and it's cell size and number
 308  * @np: pointer to device node with the property
 309  * @list_name: property that contains the list
 310  * @list: pointer for the list found
 311  * @cells_size: pointer for the cell size found
 312  * @nr_elements: pointer for the number of elements found
 313  *
 314  * Typically np is a single pinctrl entry containing the list.
 315  */
 316 static int pinctrl_get_list_and_count(const struct device_node *np,
 317                                       const char *list_name,
 318                                       const __be32 **list,
 319                                       int *cells_size,
 320                                       int *nr_elements)
 321 {
 322         int size;
 323 
 324         *cells_size = 0;
 325         *nr_elements = 0;
 326 
 327         *list = of_get_property(np, list_name, &size);
 328         if (!*list)
 329                 return -ENOENT;
 330 
 331         *cells_size = pinctrl_find_cells_size(np);
 332         if (*cells_size < 0)
 333                 return -ENOENT;
 334 
 335         /* First element is always the index within the pinctrl device */
 336         *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
 337 
 338         return 0;
 339 }
 340 
 341 /**
 342  * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
 343  * @np: pointer to device node with the property
 344  * @list_name: property that contains the list
 345  *
 346  * Counts the number of elements in a pinctrl array consisting of an index
 347  * within the controller and a number of u32 entries specified for each
 348  * entry. Note that device_node is always for the parent pin controller device.
 349  */
 350 int pinctrl_count_index_with_args(const struct device_node *np,
 351                                   const char *list_name)
 352 {
 353         const __be32 *list;
 354         int size, nr_cells, error;
 355 
 356         error = pinctrl_get_list_and_count(np, list_name, &list,
 357                                            &nr_cells, &size);
 358         if (error)
 359                 return error;
 360 
 361         return size;
 362 }
 363 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
 364 
 365 /**
 366  * pinctrl_copy_args - Populates of_phandle_args based on index
 367  * @np: pointer to device node with the property
 368  * @list: pointer to a list with the elements
 369  * @index: entry within the list of elements
 370  * @nr_cells: number of cells in the list
 371  * @nr_elem: number of elements for each entry in the list
 372  * @out_args: returned values
 373  *
 374  * Populates the of_phandle_args based on the index in the list.
 375  */
 376 static int pinctrl_copy_args(const struct device_node *np,
 377                              const __be32 *list,
 378                              int index, int nr_cells, int nr_elem,
 379                              struct of_phandle_args *out_args)
 380 {
 381         int i;
 382 
 383         memset(out_args, 0, sizeof(*out_args));
 384         out_args->np = (struct device_node *)np;
 385         out_args->args_count = nr_cells + 1;
 386 
 387         if (index >= nr_elem)
 388                 return -EINVAL;
 389 
 390         list += index * (nr_cells + 1);
 391 
 392         for (i = 0; i < nr_cells + 1; i++)
 393                 out_args->args[i] = be32_to_cpup(list++);
 394 
 395         return 0;
 396 }
 397 
 398 /**
 399  * pinctrl_parse_index_with_args - Find a node pointed by index in a list
 400  * @np: pointer to device node with the property
 401  * @list_name: property that contains the list
 402  * @index: index within the list
 403  * @out_arts: entries in the list pointed by index
 404  *
 405  * Finds the selected element in a pinctrl array consisting of an index
 406  * within the controller and a number of u32 entries specified for each
 407  * entry. Note that device_node is always for the parent pin controller device.
 408  */
 409 int pinctrl_parse_index_with_args(const struct device_node *np,
 410                                   const char *list_name, int index,
 411                                   struct of_phandle_args *out_args)
 412 {
 413         const __be32 *list;
 414         int nr_elem, nr_cells, error;
 415 
 416         error = pinctrl_get_list_and_count(np, list_name, &list,
 417                                            &nr_cells, &nr_elem);
 418         if (error || !nr_cells)
 419                 return error;
 420 
 421         error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
 422                                   out_args);
 423         if (error)
 424                 return error;
 425 
 426         return 0;
 427 }
 428 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);