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); 416