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 *pctldev,
 105                                 const char *statename,
 106                                 struct device_node *np_config)
 107 {
 108         struct device_node *np_pctldev;
 109         const struct pinctrl_ops *ops;
 110         int ret;
 111         struct pinctrl_map *map;
 112         unsigned num_maps;
 113
 114         /* Find the pin controller containing np_config */
 115         np_pctldev = of_node_get(np_config);
 116         for (;;) {
 117                 np_pctldev = of_get_next_parent(np_pctldev);
 118                 if (!np_pctldev || of_node_is_root(np_pctldev)) {
 119                         dev_info(p->dev, "could not find pctldev for node %pOF, deferring probe\n",
 120                                 np_config);
 121                         of_node_put(np_pctldev);
 122                         /* OK let's just assume this will appear later then */
 123                         return -EPROBE_DEFER;
 124                 }
 125                 if (!pctldev)
 126                         pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
 127                 if (pctldev)
 128                         break;
 129                 /* Do not defer probing of hogs (circular loop) */
 130                 if (np_pctldev == p->dev->of_node) {
 131                         of_node_put(np_pctldev);
 132                         return -ENODEV;
 133                 }
 134         }
 135         of_node_put(np_pctldev);
 136
 137         /*
 138          * Call pinctrl driver to parse device tree node, and
 139          * generate mapping table entries
 140          */
 141         ops = pctldev->desc->pctlops;
 142         if (!ops->dt_node_to_map) {
 143                 dev_err(p->dev, "pctldev %s doesn't support DT\n",
 144                         dev_name(pctldev->dev));
 145                 return -ENODEV;
 146         }
 147         ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
 148         if (ret < 0)
 149                 return ret;
 150
 151         /* Stash the mapping table chunk away for later use */
 152         return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
 153 }
 154
 155 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
 156 {
 157         struct pinctrl_map *map;
 158
 159         map = kzalloc(sizeof(*map), GFP_KERNEL);
 160         if (!map)
 161                 return -ENOMEM;
 162
 163         /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
 164         map->type = PIN_MAP_TYPE_DUMMY_STATE;
 165
 166         return dt_remember_or_free_map(p, statename, NULL, map, 1);
 167 }
 168
 169 bool pinctrl_dt_has_hogs(struct pinctrl_dev *pctldev)
 170 {
 171         struct device_node *np;
 172         struct property *prop;
 173         int size;
 174
 175         np = pctldev->dev->of_node;
 176         if (!np)
 177                 return false;
 178
 179         prop = of_find_property(np, "pinctrl-0", &size);
 180
 181         return prop ? true : false;
 182 }
 183
 184 int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
 185 {
 186         struct device_node *np = p->dev->of_node;
 187         int state, ret;
 188         char *propname;
 189         struct property *prop;
 190         const char *statename;
 191         const __be32 *list;
 192         int size, config;
 193         phandle phandle;
 194         struct device_node *np_config;
 195
 196         /* CONFIG_OF enabled, p->dev not instantiated from DT */
 197         if (!np) {
 198                 if (of_have_populated_dt())
 199                         dev_dbg(p->dev,
 200                                 "no of_node; not parsing pinctrl DT\n");
 201                 return 0;
 202         }
 203
 204         /* We may store pointers to property names within the node */
 205         of_node_get(np);
 206
 207         /* For each defined state ID */
 208         for (state = 0; ; state++) {
 209                 /* Retrieve the pinctrl-* property */
 210                 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
 211                 prop = of_find_property(np, propname, &size);
 212                 kfree(propname);
 213                 if (!prop) {
 214                         if (state == 0) {
 215                                 of_node_put(np);
 216                                 return -ENODEV;
 217                         }
 218                         break;
 219                 }
 220                 list = prop->value;
 221                 size /= sizeof(*list);
 222
 223                 /* Determine whether pinctrl-names property names the state */
 224                 ret = of_property_read_string_index(np, "pinctrl-names",
 225                                                     state, &statename);
 226                 /*
 227                  * If not, statename is just the integer state ID. But rather
 228                  * than dynamically allocate it and have to free it later,
 229                  * just point part way into the property name for the string.
 230                  */
 231                 if (ret < 0) {
 232                         /* strlen("pinctrl-") == 8 */
 233                         statename = prop->name + 8;
 234                 }
 235
 236                 /* For every referenced pin configuration node in it */
 237                 for (config = 0; config < size; config++) {
 238                         phandle = be32_to_cpup(list++);
 239
 240                         /* Look up the pin configuration node */
 241                         np_config = of_find_node_by_phandle(phandle);
 242                         if (!np_config) {
 243                                 dev_err(p->dev,
 244                                         "prop %s index %i invalid phandle\n",
 245                                         prop->name, config);
 246                                 ret = -EINVAL;
 247                                 goto err;
 248                         }
 249
 250                         /* Parse the node */
 251                         ret = dt_to_map_one_config(p, pctldev, statename,
 252                                                    np_config);
 253                         of_node_put(np_config);
 254                         if (ret < 0)
 255                                 goto err;
 256                 }
 257
 258                 /* No entries in DT? Generate a dummy state table entry */
 259                 if (!size) {
 260                         ret = dt_remember_dummy_state(p, statename);
 261                         if (ret < 0)
 262                                 goto err;
 263                 }
 264         }
 265
 266         return 0;
 267
 268 err:
 269         pinctrl_dt_free_maps(p);
 270         return ret;
 271 }
 272
 273 /*
 274  * For pinctrl binding, typically #pinctrl-cells is for the pin controller
 275  * device, so either parent or grandparent. See pinctrl-bindings.txt.
 276  */
 277 static int pinctrl_find_cells_size(const struct device_node *np)
 278 {
 279         const char *cells_name = "#pinctrl-cells";
 280         int cells_size, error;
 281
 282         error = of_property_read_u32(np->parent, cells_name, &cells_size);
 283         if (error) {
 284                 error = of_property_read_u32(np->parent->parent,
 285                                              cells_name, &cells_size);
 286                 if (error)
 287                         return -ENOENT;
 288         }
 289
 290         return cells_size;
 291 }
 292
 293 /**
 294  * pinctrl_get_list_and_count - Gets the list and it's cell size and number
 295  * @np: pointer to device node with the property
 296  * @list_name: property that contains the list
 297  * @list: pointer for the list found
 298  * @cells_size: pointer for the cell size found
 299  * @nr_elements: pointer for the number of elements found
 300  *
 301  * Typically np is a single pinctrl entry containing the list.
 302  */
 303 static int pinctrl_get_list_and_count(const struct device_node *np,
 304                                       const char *list_name,
 305                                       const __be32 **list,
 306                                       int *cells_size,
 307                                       int *nr_elements)
 308 {
 309         int size;
 310
 311         *cells_size = 0;
 312         *nr_elements = 0;
 313
 314         *list = of_get_property(np, list_name, &size);
 315         if (!*list)
 316                 return -ENOENT;
 317
 318         *cells_size = pinctrl_find_cells_size(np);
 319         if (*cells_size < 0)
 320                 return -ENOENT;
 321
 322         /* First element is always the index within the pinctrl device */
 323         *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
 324
 325         return 0;
 326 }
 327
 328 /**
 329  * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
 330  * @np: pointer to device node with the property
 331  * @list_name: property that contains the list
 332  *
 333  * Counts the number of elements in a pinctrl array consisting of an index
 334  * within the controller and a number of u32 entries specified for each
 335  * entry. Note that device_node is always for the parent pin controller device.
 336  */
 337 int pinctrl_count_index_with_args(const struct device_node *np,
 338                                   const char *list_name)
 339 {
 340         const __be32 *list;
 341         int size, nr_cells, error;
 342
 343         error = pinctrl_get_list_and_count(np, list_name, &list,
 344                                            &nr_cells, &size);
 345         if (error)
 346                 return error;
 347
 348         return size;
 349 }
 350 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
 351
 352 /**
 353  * pinctrl_copy_args - Populates of_phandle_args based on index
 354  * @np: pointer to device node with the property
 355  * @list: pointer to a list with the elements
 356  * @index: entry within the list of elements
 357  * @nr_cells: number of cells in the list
 358  * @nr_elem: number of elements for each entry in the list
 359  * @out_args: returned values
 360  *
 361  * Populates the of_phandle_args based on the index in the list.
 362  */
 363 static int pinctrl_copy_args(const struct device_node *np,
 364                              const __be32 *list,
 365                              int index, int nr_cells, int nr_elem,
 366                              struct of_phandle_args *out_args)
 367 {
 368         int i;
 369
 370         memset(out_args, 0, sizeof(*out_args));
 371         out_args->np = (struct device_node *)np;
 372         out_args->args_count = nr_cells + 1;
 373
 374         if (index >= nr_elem)
 375                 return -EINVAL;
 376
 377         list += index * (nr_cells + 1);
 378
 379         for (i = 0; i < nr_cells + 1; i++)
 380                 out_args->args[i] = be32_to_cpup(list++);
 381
 382         return 0;
 383 }
 384
 385 /**
 386  * pinctrl_parse_index_with_args - Find a node pointed by index in a list
 387  * @np: pointer to device node with the property
 388  * @list_name: property that contains the list
 389  * @index: index within the list
 390  * @out_arts: entries in the list pointed by index
 391  *
 392  * Finds the selected element in a pinctrl array consisting of an index
 393  * within the controller and a number of u32 entries specified for each
 394  * entry. Note that device_node is always for the parent pin controller device.
 395  */
 396 int pinctrl_parse_index_with_args(const struct device_node *np,
 397                                   const char *list_name, int index,
 398                                   struct of_phandle_args *out_args)
 399 {
 400         const __be32 *list;
 401         int nr_elem, nr_cells, error;
 402
 403         error = pinctrl_get_list_and_count(np, list_name, &list,
 404                                            &nr_cells, &nr_elem);
 405         if (error || !nr_cells)
 406                 return error;
 407
 408         error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
 409                                   out_args);
 410         if (error)
 411                 return error;
 412
 413         return 0;
 414 }
 415 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);