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 num_maps; 28 }; 29 30 static void dt_free_map(struct pinctrl_dev *pctldev, 31 struct pinctrl_map *map, unsigned 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 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 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 /* Do not defer probing of hogs (circular loop) */ 147 if (np_pctldev == p->dev->of_node) { 148 of_node_put(np_pctldev); 149 return -ENODEV; 150 } 151 } 152 of_node_put(np_pctldev); 153 154 /* 155 * Call pinctrl driver to parse device tree node, and 156 * generate mapping table entries 157 */ 158 ops = pctldev->desc->pctlops; 159 if (!ops->dt_node_to_map) { 160 dev_err(p->dev, "pctldev %s doesn't support DT\n", 161 dev_name(pctldev->dev)); 162 return -ENODEV; 163 } 164 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps); 165 if (ret < 0) 166 return ret; 167 else if (num_maps == 0) { 168 /* 169 * If we have no valid maps (maybe caused by empty pinctrl node 170 * or typing error) ther is no need remember this, so just 171 * return. 172 */ 173 dev_info(p->dev, 174 "there is not valid maps for state %s\n", statename); 175 return 0; 176 } 177 178 /* Stash the mapping table chunk away for later use */ 179 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps); 180 } 181 182 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename) 183 { 184 struct pinctrl_map *map; 185 186 map = kzalloc(sizeof(*map), GFP_KERNEL); 187 if (!map) 188 return -ENOMEM; 189 190 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ 191 map->type = PIN_MAP_TYPE_DUMMY_STATE; 192 193 return dt_remember_or_free_map(p, statename, NULL, map, 1); 194 } 195 196 int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev) 197 { 198 struct device_node *np = p->dev->of_node; 199 int state, ret; 200 char *propname; 201 struct property *prop; 202 const char *statename; 203 const __be32 *list; 204 int size, config; 205 phandle phandle; 206 struct device_node *np_config; 207 208 /* CONFIG_OF enabled, p->dev not instantiated from DT */ 209 if (!np) { 210 if (of_have_populated_dt()) 211 dev_dbg(p->dev, 212 "no of_node; not parsing pinctrl DT\n"); 213 return 0; 214 } 215 216 /* We may store pointers to property names within the node */ 217 of_node_get(np); 218 219 /* For each defined state ID */ 220 for (state = 0; ; state++) { 221 /* Retrieve the pinctrl-* property */ 222 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state); 223 prop = of_find_property(np, propname, &size); 224 kfree(propname); 225 if (!prop) { 226 if (state == 0) { 227 of_node_put(np); 228 return -ENODEV; 229 } 230 break; 231 } 232 list = prop->value; 233 size /= sizeof(*list); 234 235 /* Determine whether pinctrl-names property names the state */ 236 ret = of_property_read_string_index(np, "pinctrl-names", 237 state, &statename); 238 /* 239 * If not, statename is just the integer state ID. But rather 240 * than dynamically allocate it and have to free it later, 241 * just point part way into the property name for the string. 242 */ 243 if (ret < 0) 244 statename = prop->name + strlen("pinctrl-"); 245 246 /* For every referenced pin configuration node in it */ 247 for (config = 0; config < size; config++) { 248 phandle = be32_to_cpup(list++); 249 250 /* Look up the pin configuration node */ 251 np_config = of_find_node_by_phandle(phandle); 252 if (!np_config) { 253 dev_err(p->dev, 254 "prop %s index %i invalid phandle\n", 255 prop->name, config); 256 ret = -EINVAL; 257 goto err; 258 } 259 260 /* Parse the node */ 261 ret = dt_to_map_one_config(p, pctldev, statename, 262 np_config); 263 of_node_put(np_config); 264 if (ret < 0) 265 goto err; 266 } 267 268 /* No entries in DT? Generate a dummy state table entry */ 269 if (!size) { 270 ret = dt_remember_dummy_state(p, statename); 271 if (ret < 0) 272 goto err; 273 } 274 } 275 276 return 0; 277 278 err: 279 pinctrl_dt_free_maps(p); 280 return ret; 281 } 282 283 /* 284 * For pinctrl binding, typically #pinctrl-cells is for the pin controller 285 * device, so either parent or grandparent. See pinctrl-bindings.txt. 286 */ 287 static int pinctrl_find_cells_size(const struct device_node *np) 288 { 289 const char *cells_name = "#pinctrl-cells"; 290 int cells_size, error; 291 292 error = of_property_read_u32(np->parent, cells_name, &cells_size); 293 if (error) { 294 error = of_property_read_u32(np->parent->parent, 295 cells_name, &cells_size); 296 if (error) 297 return -ENOENT; 298 } 299 300 return cells_size; 301 } 302 303 /** 304 * pinctrl_get_list_and_count - Gets the list and it's cell size and number 305 * @np: pointer to device node with the property 306 * @list_name: property that contains the list 307 * @list: pointer for the list found 308 * @cells_size: pointer for the cell size found 309 * @nr_elements: pointer for the number of elements found 310 * 311 * Typically np is a single pinctrl entry containing the list. 312 */ 313 static int pinctrl_get_list_and_count(const struct device_node *np, 314 const char *list_name, 315 const __be32 **list, 316 int *cells_size, 317 int *nr_elements) 318 { 319 int size; 320 321 *cells_size = 0; 322 *nr_elements = 0; 323 324 *list = of_get_property(np, list_name, &size); 325 if (!*list) 326 return -ENOENT; 327 328 *cells_size = pinctrl_find_cells_size(np); 329 if (*cells_size < 0) 330 return -ENOENT; 331 332 /* First element is always the index within the pinctrl device */ 333 *nr_elements = (size / sizeof(**list)) / (*cells_size + 1); 334 335 return 0; 336 } 337 338 /** 339 * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry 340 * @np: pointer to device node with the property 341 * @list_name: property that contains the list 342 * 343 * Counts the number of elements in a pinctrl array consisting of an index 344 * within the controller and a number of u32 entries specified for each 345 * entry. Note that device_node is always for the parent pin controller device. 346 */ 347 int pinctrl_count_index_with_args(const struct device_node *np, 348 const char *list_name) 349 { 350 const __be32 *list; 351 int size, nr_cells, error; 352 353 error = pinctrl_get_list_and_count(np, list_name, &list, 354 &nr_cells, &size); 355 if (error) 356 return error; 357 358 return size; 359 } 360 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args); 361 362 /** 363 * pinctrl_copy_args - Populates of_phandle_args based on index 364 * @np: pointer to device node with the property 365 * @list: pointer to a list with the elements 366 * @index: entry within the list of elements 367 * @nr_cells: number of cells in the list 368 * @nr_elem: number of elements for each entry in the list 369 * @out_args: returned values 370 * 371 * Populates the of_phandle_args based on the index in the list. 372 */ 373 static int pinctrl_copy_args(const struct device_node *np, 374 const __be32 *list, 375 int index, int nr_cells, int nr_elem, 376 struct of_phandle_args *out_args) 377 { 378 int i; 379 380 memset(out_args, 0, sizeof(*out_args)); 381 out_args->np = (struct device_node *)np; 382 out_args->args_count = nr_cells + 1; 383 384 if (index >= nr_elem) 385 return -EINVAL; 386 387 list += index * (nr_cells + 1); 388 389 for (i = 0; i < nr_cells + 1; i++) 390 out_args->args[i] = be32_to_cpup(list++); 391 392 return 0; 393 } 394 395 /** 396 * pinctrl_parse_index_with_args - Find a node pointed by index in a list 397 * @np: pointer to device node with the property 398 * @list_name: property that contains the list 399 * @index: index within the list 400 * @out_args: entries in the list pointed by index 401 * 402 * Finds the selected element in a pinctrl array consisting of an index 403 * within the controller and a number of u32 entries specified for each 404 * entry. Note that device_node is always for the parent pin controller device. 405 */ 406 int pinctrl_parse_index_with_args(const struct device_node *np, 407 const char *list_name, int index, 408 struct of_phandle_args *out_args) 409 { 410 const __be32 *list; 411 int nr_elem, nr_cells, error; 412 413 error = pinctrl_get_list_and_count(np, list_name, &list, 414 &nr_cells, &nr_elem); 415 if (error || !nr_cells) 416 return error; 417 418 error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem, 419 out_args); 420 if (error) 421 return error; 422 423 return 0; 424 } 425 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args); 426