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