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 dev_err(p->dev, "failed to alloc struct pinctrl_dt_map\n"); 87 dt_free_map(pctldev, map, num_maps); 88 return -ENOMEM; 89 } 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_map(map, num_maps, false); 97 } 98 99 struct pinctrl_dev *of_pinctrl_get(struct device_node *np) 100 { 101 return get_pinctrl_dev_from_of_node(np); 102 } 103 104 static int dt_to_map_one_config(struct pinctrl *p, 105 struct pinctrl_dev *pctldev, 106 const char *statename, 107 struct device_node *np_config) 108 { 109 struct device_node *np_pctldev; 110 const struct pinctrl_ops *ops; 111 int ret; 112 struct pinctrl_map *map; 113 unsigned num_maps; 114 115 /* Find the pin controller containing np_config */ 116 np_pctldev = of_node_get(np_config); 117 for (;;) { 118 np_pctldev = of_get_next_parent(np_pctldev); 119 if (!np_pctldev || of_node_is_root(np_pctldev)) { 120 dev_info(p->dev, "could not find pctldev for node %s, deferring probe\n", 121 np_config->full_name); 122 of_node_put(np_pctldev); 123 /* OK let's just assume this will appear later then */ 124 return -EPROBE_DEFER; 125 } 126 if (!pctldev) 127 pctldev = get_pinctrl_dev_from_of_node(np_pctldev); 128 if (pctldev) 129 break; 130 /* Do not defer probing of hogs (circular loop) */ 131 if (np_pctldev == p->dev->of_node) { 132 of_node_put(np_pctldev); 133 return -ENODEV; 134 } 135 } 136 of_node_put(np_pctldev); 137 138 /* 139 * Call pinctrl driver to parse device tree node, and 140 * generate mapping table entries 141 */ 142 ops = pctldev->desc->pctlops; 143 if (!ops->dt_node_to_map) { 144 dev_err(p->dev, "pctldev %s doesn't support DT\n", 145 dev_name(pctldev->dev)); 146 return -ENODEV; 147 } 148 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps); 149 if (ret < 0) 150 return ret; 151 152 /* Stash the mapping table chunk away for later use */ 153 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps); 154 } 155 156 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename) 157 { 158 struct pinctrl_map *map; 159 160 map = kzalloc(sizeof(*map), GFP_KERNEL); 161 if (!map) { 162 dev_err(p->dev, "failed to alloc struct pinctrl_map\n"); 163 return -ENOMEM; 164 } 165 166 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ 167 map->type = PIN_MAP_TYPE_DUMMY_STATE; 168 169 return dt_remember_or_free_map(p, statename, NULL, map, 1); 170 } 171 172 bool pinctrl_dt_has_hogs(struct pinctrl_dev *pctldev) 173 { 174 struct device_node *np; 175 struct property *prop; 176 int size; 177 178 np = pctldev->dev->of_node; 179 if (!np) 180 return false; 181 182 prop = of_find_property(np, "pinctrl-0", &size); 183 184 return prop ? true : false; 185 } 186 187 int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev) 188 { 189 struct device_node *np = p->dev->of_node; 190 int state, ret; 191 char *propname; 192 struct property *prop; 193 const char *statename; 194 const __be32 *list; 195 int size, config; 196 phandle phandle; 197 struct device_node *np_config; 198 199 /* CONFIG_OF enabled, p->dev not instantiated from DT */ 200 if (!np) { 201 if (of_have_populated_dt()) 202 dev_dbg(p->dev, 203 "no of_node; not parsing pinctrl DT\n"); 204 return 0; 205 } 206 207 /* We may store pointers to property names within the node */ 208 of_node_get(np); 209 210 /* For each defined state ID */ 211 for (state = 0; ; state++) { 212 /* Retrieve the pinctrl-* property */ 213 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state); 214 prop = of_find_property(np, propname, &size); 215 kfree(propname); 216 if (!prop) { 217 if (state == 0) { 218 of_node_put(np); 219 return -ENODEV; 220 } 221 break; 222 } 223 list = prop->value; 224 size /= sizeof(*list); 225 226 /* Determine whether pinctrl-names property names the state */ 227 ret = of_property_read_string_index(np, "pinctrl-names", 228 state, &statename); 229 /* 230 * If not, statename is just the integer state ID. But rather 231 * than dynamically allocate it and have to free it later, 232 * just point part way into the property name for the string. 233 */ 234 if (ret < 0) { 235 /* strlen("pinctrl-") == 8 */ 236 statename = prop->name + 8; 237 } 238 239 /* For every referenced pin configuration node in it */ 240 for (config = 0; config < size; config++) { 241 phandle = be32_to_cpup(list++); 242 243 /* Look up the pin configuration node */ 244 np_config = of_find_node_by_phandle(phandle); 245 if (!np_config) { 246 dev_err(p->dev, 247 "prop %s index %i invalid phandle\n", 248 prop->name, config); 249 ret = -EINVAL; 250 goto err; 251 } 252 253 /* Parse the node */ 254 ret = dt_to_map_one_config(p, pctldev, statename, 255 np_config); 256 of_node_put(np_config); 257 if (ret < 0) 258 goto err; 259 } 260 261 /* No entries in DT? Generate a dummy state table entry */ 262 if (!size) { 263 ret = dt_remember_dummy_state(p, statename); 264 if (ret < 0) 265 goto err; 266 } 267 } 268 269 return 0; 270 271 err: 272 pinctrl_dt_free_maps(p); 273 return ret; 274 } 275 276 /* 277 * For pinctrl binding, typically #pinctrl-cells is for the pin controller 278 * device, so either parent or grandparent. See pinctrl-bindings.txt. 279 */ 280 static int pinctrl_find_cells_size(const struct device_node *np) 281 { 282 const char *cells_name = "#pinctrl-cells"; 283 int cells_size, error; 284 285 error = of_property_read_u32(np->parent, cells_name, &cells_size); 286 if (error) { 287 error = of_property_read_u32(np->parent->parent, 288 cells_name, &cells_size); 289 if (error) 290 return -ENOENT; 291 } 292 293 return cells_size; 294 } 295 296 /** 297 * pinctrl_get_list_and_count - Gets the list and it's cell size and number 298 * @np: pointer to device node with the property 299 * @list_name: property that contains the list 300 * @list: pointer for the list found 301 * @cells_size: pointer for the cell size found 302 * @nr_elements: pointer for the number of elements found 303 * 304 * Typically np is a single pinctrl entry containing the list. 305 */ 306 static int pinctrl_get_list_and_count(const struct device_node *np, 307 const char *list_name, 308 const __be32 **list, 309 int *cells_size, 310 int *nr_elements) 311 { 312 int size; 313 314 *cells_size = 0; 315 *nr_elements = 0; 316 317 *list = of_get_property(np, list_name, &size); 318 if (!*list) 319 return -ENOENT; 320 321 *cells_size = pinctrl_find_cells_size(np); 322 if (*cells_size < 0) 323 return -ENOENT; 324 325 /* First element is always the index within the pinctrl device */ 326 *nr_elements = (size / sizeof(**list)) / (*cells_size + 1); 327 328 return 0; 329 } 330 331 /** 332 * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry 333 * @np: pointer to device node with the property 334 * @list_name: property that contains the list 335 * 336 * Counts the number of elements in a pinctrl array consisting of an index 337 * within the controller and a number of u32 entries specified for each 338 * entry. Note that device_node is always for the parent pin controller device. 339 */ 340 int pinctrl_count_index_with_args(const struct device_node *np, 341 const char *list_name) 342 { 343 const __be32 *list; 344 int size, nr_cells, error; 345 346 error = pinctrl_get_list_and_count(np, list_name, &list, 347 &nr_cells, &size); 348 if (error) 349 return error; 350 351 return size; 352 } 353 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args); 354 355 /** 356 * pinctrl_copy_args - Populates of_phandle_args based on index 357 * @np: pointer to device node with the property 358 * @list: pointer to a list with the elements 359 * @index: entry within the list of elements 360 * @nr_cells: number of cells in the list 361 * @nr_elem: number of elements for each entry in the list 362 * @out_args: returned values 363 * 364 * Populates the of_phandle_args based on the index in the list. 365 */ 366 static int pinctrl_copy_args(const struct device_node *np, 367 const __be32 *list, 368 int index, int nr_cells, int nr_elem, 369 struct of_phandle_args *out_args) 370 { 371 int i; 372 373 memset(out_args, 0, sizeof(*out_args)); 374 out_args->np = (struct device_node *)np; 375 out_args->args_count = nr_cells + 1; 376 377 if (index >= nr_elem) 378 return -EINVAL; 379 380 list += index * (nr_cells + 1); 381 382 for (i = 0; i < nr_cells + 1; i++) 383 out_args->args[i] = be32_to_cpup(list++); 384 385 return 0; 386 } 387 388 /** 389 * pinctrl_parse_index_with_args - Find a node pointed by index in a list 390 * @np: pointer to device node with the property 391 * @list_name: property that contains the list 392 * @index: index within the list 393 * @out_arts: entries in the list pointed by index 394 * 395 * Finds the selected element in a pinctrl array consisting of an index 396 * within the controller and a number of u32 entries specified for each 397 * entry. Note that device_node is always for the parent pin controller device. 398 */ 399 int pinctrl_parse_index_with_args(const struct device_node *np, 400 const char *list_name, int index, 401 struct of_phandle_args *out_args) 402 { 403 const __be32 *list; 404 int nr_elem, nr_cells, error; 405 406 error = pinctrl_get_list_and_count(np, list_name, &list, 407 &nr_cells, &nr_elem); 408 if (error || !nr_cells) 409 return error; 410 411 error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem, 412 out_args); 413 if (error) 414 return error; 415 416 return 0; 417 } 418 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args); 419