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 * @map: the mapping table entries 21 * @num_maps: number of mapping table entries 22 */ 23 struct pinctrl_dt_map { 24 struct list_head node; 25 struct pinctrl_dev *pctldev; 26 struct pinctrl_map *map; 27 unsigned int num_maps; 28 }; 29 30 static void dt_free_map(struct pinctrl_dev *pctldev, 31 struct pinctrl_map *map, unsigned int num_maps) 32 { 33 int i; 34 35 for (i = 0; i < num_maps; ++i) { 36 kfree_const(map[i].dev_name); 37 map[i].dev_name = NULL; 38 } 39 40 if (pctldev) { 41 const struct pinctrl_ops *ops = pctldev->desc->pctlops; 42 if (ops->dt_free_map) 43 ops->dt_free_map(pctldev, map, num_maps); 44 } else { 45 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ 46 kfree(map); 47 } 48 } 49 50 void pinctrl_dt_free_maps(struct pinctrl *p) 51 { 52 struct pinctrl_dt_map *dt_map, *n1; 53 54 list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) { 55 pinctrl_unregister_mappings(dt_map->map); 56 list_del(&dt_map->node); 57 dt_free_map(dt_map->pctldev, dt_map->map, 58 dt_map->num_maps); 59 kfree(dt_map); 60 } 61 62 of_node_put(p->dev->of_node); 63 } 64 65 static int dt_remember_or_free_map(struct pinctrl *p, const char *statename, 66 struct pinctrl_dev *pctldev, 67 struct pinctrl_map *map, unsigned int num_maps) 68 { 69 int i; 70 struct pinctrl_dt_map *dt_map; 71 72 /* Initialize common mapping table entry fields */ 73 for (i = 0; i < num_maps; i++) { 74 const char *devname; 75 76 devname = kstrdup_const(dev_name(p->dev), GFP_KERNEL); 77 if (!devname) 78 goto err_free_map; 79 80 map[i].dev_name = devname; 81 map[i].name = statename; 82 if (pctldev) 83 map[i].ctrl_dev_name = dev_name(pctldev->dev); 84 } 85 86 /* Remember the converted mapping table entries */ 87 dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL); 88 if (!dt_map) 89 goto err_free_map; 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_mappings(map, num_maps); 97 98 err_free_map: 99 dt_free_map(pctldev, map, num_maps); 100 return -ENOMEM; 101 } 102 103 struct pinctrl_dev *of_pinctrl_get(struct device_node *np) 104 { 105 return get_pinctrl_dev_from_of_node(np); 106 } 107 EXPORT_SYMBOL_GPL(of_pinctrl_get); 108 109 static int dt_to_map_one_config(struct pinctrl *p, 110 struct pinctrl_dev *hog_pctldev, 111 const char *statename, 112 struct device_node *np_config) 113 { 114 struct pinctrl_dev *pctldev = NULL; 115 struct device_node *np_pctldev; 116 const struct pinctrl_ops *ops; 117 int ret; 118 struct pinctrl_map *map; 119 unsigned int num_maps; 120 bool allow_default = false; 121 122 /* Find the pin controller containing np_config */ 123 np_pctldev = of_node_get(np_config); 124 for (;;) { 125 if (!allow_default) 126 allow_default = of_property_read_bool(np_pctldev, 127 "pinctrl-use-default"); 128 129 np_pctldev = of_get_next_parent(np_pctldev); 130 if (!np_pctldev || of_node_is_root(np_pctldev)) { 131 of_node_put(np_pctldev); 132 ret = -ENODEV; 133 /* keep deferring if modules are enabled */ 134 if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret < 0) 135 ret = -EPROBE_DEFER; 136 return ret; 137 } 138 /* If we're creating a hog we can use the passed pctldev */ 139 if (hog_pctldev && (np_pctldev == p->dev->of_node)) { 140 pctldev = hog_pctldev; 141 break; 142 } 143 pctldev = get_pinctrl_dev_from_of_node(np_pctldev); 144 if (pctldev) 145 break; 146 /* 147 * Do not defer probing of hogs (circular loop) 148 * 149 * Return 1 to let the caller catch the case. 150 */ 151 if (np_pctldev == p->dev->of_node) { 152 of_node_put(np_pctldev); 153 return 1; 154 } 155 } 156 of_node_put(np_pctldev); 157 158 /* 159 * Call pinctrl driver to parse device tree node, and 160 * generate mapping table entries 161 */ 162 ops = pctldev->desc->pctlops; 163 if (!ops->dt_node_to_map) { 164 dev_err(p->dev, "pctldev %s doesn't support DT\n", 165 dev_name(pctldev->dev)); 166 return -ENODEV; 167 } 168 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps); 169 if (ret < 0) 170 return ret; 171 else if (num_maps == 0) { 172 /* 173 * If we have no valid maps (maybe caused by empty pinctrl node 174 * or typing error) ther is no need remember this, so just 175 * return. 176 */ 177 dev_info(p->dev, 178 "there is not valid maps for state %s\n", statename); 179 return 0; 180 } 181 182 /* Stash the mapping table chunk away for later use */ 183 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps); 184 } 185 186 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename) 187 { 188 struct pinctrl_map *map; 189 190 map = kzalloc(sizeof(*map), GFP_KERNEL); 191 if (!map) 192 return -ENOMEM; 193 194 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ 195 map->type = PIN_MAP_TYPE_DUMMY_STATE; 196 197 return dt_remember_or_free_map(p, statename, NULL, map, 1); 198 } 199 200 int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev) 201 { 202 struct device_node *np = p->dev->of_node; 203 int state, ret; 204 char *propname; 205 struct property *prop; 206 const char *statename; 207 const __be32 *list; 208 int size, config; 209 phandle phandle; 210 struct device_node *np_config; 211 212 /* CONFIG_OF enabled, p->dev not instantiated from DT */ 213 if (!np) { 214 if (of_have_populated_dt()) 215 dev_dbg(p->dev, 216 "no of_node; not parsing pinctrl DT\n"); 217 return 0; 218 } 219 220 /* We may store pointers to property names within the node */ 221 of_node_get(np); 222 223 /* For each defined state ID */ 224 for (state = 0; ; state++) { 225 /* Retrieve the pinctrl-* property */ 226 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state); 227 if (!propname) { 228 ret = -ENOMEM; 229 goto err; 230 } 231 prop = of_find_property(np, propname, &size); 232 kfree(propname); 233 if (!prop) { 234 if (state == 0) { 235 ret = -ENODEV; 236 goto err; 237 } 238 break; 239 } 240 list = prop->value; 241 size /= sizeof(*list); 242 243 /* Determine whether pinctrl-names property names the state */ 244 ret = of_property_read_string_index(np, "pinctrl-names", 245 state, &statename); 246 /* 247 * If not, statename is just the integer state ID. But rather 248 * than dynamically allocate it and have to free it later, 249 * just point part way into the property name for the string. 250 */ 251 if (ret < 0) 252 statename = prop->name + strlen("pinctrl-"); 253 254 /* For every referenced pin configuration node in it */ 255 for (config = 0; config < size; config++) { 256 phandle = be32_to_cpup(list++); 257 258 /* Look up the pin configuration node */ 259 np_config = of_find_node_by_phandle(phandle); 260 if (!np_config) { 261 dev_err(p->dev, 262 "prop %s index %i invalid phandle\n", 263 prop->name, config); 264 ret = -EINVAL; 265 goto err; 266 } 267 268 /* Parse the node */ 269 ret = dt_to_map_one_config(p, pctldev, statename, 270 np_config); 271 of_node_put(np_config); 272 if (ret == 1) 273 continue; 274 if (ret < 0) 275 goto err; 276 } 277 278 /* No entries in DT? Generate a dummy state table entry */ 279 if (!size) { 280 ret = dt_remember_dummy_state(p, statename); 281 if (ret < 0) 282 goto err; 283 } 284 } 285 286 return 0; 287 288 err: 289 pinctrl_dt_free_maps(p); 290 return ret; 291 } 292 293 /* 294 * For pinctrl binding, typically #pinctrl-cells is for the pin controller 295 * device, so either parent or grandparent. See pinctrl-bindings.txt. 296 */ 297 static int pinctrl_find_cells_size(const struct device_node *np) 298 { 299 const char *cells_name = "#pinctrl-cells"; 300 int cells_size, error; 301 302 error = of_property_read_u32(np->parent, cells_name, &cells_size); 303 if (error) { 304 error = of_property_read_u32(np->parent->parent, 305 cells_name, &cells_size); 306 if (error) 307 return -ENOENT; 308 } 309 310 return cells_size; 311 } 312 313 /** 314 * pinctrl_get_list_and_count - Gets the list and it's cell size and number 315 * @np: pointer to device node with the property 316 * @list_name: property that contains the list 317 * @list: pointer for the list found 318 * @cells_size: pointer for the cell size found 319 * @nr_elements: pointer for the number of elements found 320 * 321 * Typically np is a single pinctrl entry containing the list. 322 */ 323 static int pinctrl_get_list_and_count(const struct device_node *np, 324 const char *list_name, 325 const __be32 **list, 326 int *cells_size, 327 int *nr_elements) 328 { 329 int size; 330 331 *cells_size = 0; 332 *nr_elements = 0; 333 334 *list = of_get_property(np, list_name, &size); 335 if (!*list) 336 return -ENOENT; 337 338 *cells_size = pinctrl_find_cells_size(np); 339 if (*cells_size < 0) 340 return -ENOENT; 341 342 /* First element is always the index within the pinctrl device */ 343 *nr_elements = (size / sizeof(**list)) / (*cells_size + 1); 344 345 return 0; 346 } 347 348 /** 349 * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry 350 * @np: pointer to device node with the property 351 * @list_name: property that contains the list 352 * 353 * Counts the number of elements in a pinctrl array consisting of an index 354 * within the controller and a number of u32 entries specified for each 355 * entry. Note that device_node is always for the parent pin controller device. 356 */ 357 int pinctrl_count_index_with_args(const struct device_node *np, 358 const char *list_name) 359 { 360 const __be32 *list; 361 int size, nr_cells, error; 362 363 error = pinctrl_get_list_and_count(np, list_name, &list, 364 &nr_cells, &size); 365 if (error) 366 return error; 367 368 return size; 369 } 370 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args); 371 372 /** 373 * pinctrl_copy_args - Populates of_phandle_args based on index 374 * @np: pointer to device node with the property 375 * @list: pointer to a list with the elements 376 * @index: entry within the list of elements 377 * @nr_cells: number of cells in the list 378 * @nr_elem: number of elements for each entry in the list 379 * @out_args: returned values 380 * 381 * Populates the of_phandle_args based on the index in the list. 382 */ 383 static int pinctrl_copy_args(const struct device_node *np, 384 const __be32 *list, 385 int index, int nr_cells, int nr_elem, 386 struct of_phandle_args *out_args) 387 { 388 int i; 389 390 memset(out_args, 0, sizeof(*out_args)); 391 out_args->np = (struct device_node *)np; 392 out_args->args_count = nr_cells + 1; 393 394 if (index >= nr_elem) 395 return -EINVAL; 396 397 list += index * (nr_cells + 1); 398 399 for (i = 0; i < nr_cells + 1; i++) 400 out_args->args[i] = be32_to_cpup(list++); 401 402 return 0; 403 } 404 405 /** 406 * pinctrl_parse_index_with_args - Find a node pointed by index in a list 407 * @np: pointer to device node with the property 408 * @list_name: property that contains the list 409 * @index: index within the list 410 * @out_args: entries in the list pointed by index 411 * 412 * Finds the selected element in a pinctrl array consisting of an index 413 * within the controller and a number of u32 entries specified for each 414 * entry. Note that device_node is always for the parent pin controller device. 415 */ 416 int pinctrl_parse_index_with_args(const struct device_node *np, 417 const char *list_name, int index, 418 struct of_phandle_args *out_args) 419 { 420 const __be32 *list; 421 int nr_elem, nr_cells, error; 422 423 error = pinctrl_get_list_and_count(np, list_name, &list, 424 &nr_cells, &nr_elem); 425 if (error || !nr_cells) 426 return error; 427 428 error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem, 429 out_args); 430 if (error) 431 return error; 432 433 return 0; 434 } 435 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args); 436