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 = driver_deferred_probe_check_state(p->dev); 133 /* keep deferring if modules are enabled unless we've timed out */ 134 if (IS_ENABLED(CONFIG_MODULES) && !allow_default && 135 (ret == -ENODEV)) 136 ret = -EPROBE_DEFER; 137 return ret; 138 } 139 /* If we're creating a hog we can use the passed pctldev */ 140 if (hog_pctldev && (np_pctldev == p->dev->of_node)) { 141 pctldev = hog_pctldev; 142 break; 143 } 144 pctldev = get_pinctrl_dev_from_of_node(np_pctldev); 145 if (pctldev) 146 break; 147 /* Do not defer probing of hogs (circular loop) */ 148 if (np_pctldev == p->dev->of_node) { 149 of_node_put(np_pctldev); 150 return -ENODEV; 151 } 152 } 153 of_node_put(np_pctldev); 154 155 /* 156 * Call pinctrl driver to parse device tree node, and 157 * generate mapping table entries 158 */ 159 ops = pctldev->desc->pctlops; 160 if (!ops->dt_node_to_map) { 161 dev_err(p->dev, "pctldev %s doesn't support DT\n", 162 dev_name(pctldev->dev)); 163 return -ENODEV; 164 } 165 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps); 166 if (ret < 0) 167 return ret; 168 else if (num_maps == 0) { 169 /* 170 * If we have no valid maps (maybe caused by empty pinctrl node 171 * or typing error) ther is no need remember this, so just 172 * return. 173 */ 174 dev_info(p->dev, 175 "there is not valid maps for state %s\n", statename); 176 return 0; 177 } 178 179 /* Stash the mapping table chunk away for later use */ 180 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps); 181 } 182 183 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename) 184 { 185 struct pinctrl_map *map; 186 187 map = kzalloc(sizeof(*map), GFP_KERNEL); 188 if (!map) 189 return -ENOMEM; 190 191 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ 192 map->type = PIN_MAP_TYPE_DUMMY_STATE; 193 194 return dt_remember_or_free_map(p, statename, NULL, map, 1); 195 } 196 197 int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev) 198 { 199 struct device_node *np = p->dev->of_node; 200 int state, ret; 201 char *propname; 202 struct property *prop; 203 const char *statename; 204 const __be32 *list; 205 int size, config; 206 phandle phandle; 207 struct device_node *np_config; 208 209 /* CONFIG_OF enabled, p->dev not instantiated from DT */ 210 if (!np) { 211 if (of_have_populated_dt()) 212 dev_dbg(p->dev, 213 "no of_node; not parsing pinctrl DT\n"); 214 return 0; 215 } 216 217 /* We may store pointers to property names within the node */ 218 of_node_get(np); 219 220 /* For each defined state ID */ 221 for (state = 0; ; state++) { 222 /* Retrieve the pinctrl-* property */ 223 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state); 224 prop = of_find_property(np, propname, &size); 225 kfree(propname); 226 if (!prop) { 227 if (state == 0) { 228 of_node_put(np); 229 return -ENODEV; 230 } 231 break; 232 } 233 list = prop->value; 234 size /= sizeof(*list); 235 236 /* Determine whether pinctrl-names property names the state */ 237 ret = of_property_read_string_index(np, "pinctrl-names", 238 state, &statename); 239 /* 240 * If not, statename is just the integer state ID. But rather 241 * than dynamically allocate it and have to free it later, 242 * just point part way into the property name for the string. 243 */ 244 if (ret < 0) 245 statename = prop->name + strlen("pinctrl-"); 246 247 /* For every referenced pin configuration node in it */ 248 for (config = 0; config < size; config++) { 249 phandle = be32_to_cpup(list++); 250 251 /* Look up the pin configuration node */ 252 np_config = of_find_node_by_phandle(phandle); 253 if (!np_config) { 254 dev_err(p->dev, 255 "prop %s index %i invalid phandle\n", 256 prop->name, config); 257 ret = -EINVAL; 258 goto err; 259 } 260 261 /* Parse the node */ 262 ret = dt_to_map_one_config(p, pctldev, statename, 263 np_config); 264 of_node_put(np_config); 265 if (ret < 0) 266 goto err; 267 } 268 269 /* No entries in DT? Generate a dummy state table entry */ 270 if (!size) { 271 ret = dt_remember_dummy_state(p, statename); 272 if (ret < 0) 273 goto err; 274 } 275 } 276 277 return 0; 278 279 err: 280 pinctrl_dt_free_maps(p); 281 return ret; 282 } 283 284 /* 285 * For pinctrl binding, typically #pinctrl-cells is for the pin controller 286 * device, so either parent or grandparent. See pinctrl-bindings.txt. 287 */ 288 static int pinctrl_find_cells_size(const struct device_node *np) 289 { 290 const char *cells_name = "#pinctrl-cells"; 291 int cells_size, error; 292 293 error = of_property_read_u32(np->parent, cells_name, &cells_size); 294 if (error) { 295 error = of_property_read_u32(np->parent->parent, 296 cells_name, &cells_size); 297 if (error) 298 return -ENOENT; 299 } 300 301 return cells_size; 302 } 303 304 /** 305 * pinctrl_get_list_and_count - Gets the list and it's cell size and number 306 * @np: pointer to device node with the property 307 * @list_name: property that contains the list 308 * @list: pointer for the list found 309 * @cells_size: pointer for the cell size found 310 * @nr_elements: pointer for the number of elements found 311 * 312 * Typically np is a single pinctrl entry containing the list. 313 */ 314 static int pinctrl_get_list_and_count(const struct device_node *np, 315 const char *list_name, 316 const __be32 **list, 317 int *cells_size, 318 int *nr_elements) 319 { 320 int size; 321 322 *cells_size = 0; 323 *nr_elements = 0; 324 325 *list = of_get_property(np, list_name, &size); 326 if (!*list) 327 return -ENOENT; 328 329 *cells_size = pinctrl_find_cells_size(np); 330 if (*cells_size < 0) 331 return -ENOENT; 332 333 /* First element is always the index within the pinctrl device */ 334 *nr_elements = (size / sizeof(**list)) / (*cells_size + 1); 335 336 return 0; 337 } 338 339 /** 340 * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry 341 * @np: pointer to device node with the property 342 * @list_name: property that contains the list 343 * 344 * Counts the number of elements in a pinctrl array consisting of an index 345 * within the controller and a number of u32 entries specified for each 346 * entry. Note that device_node is always for the parent pin controller device. 347 */ 348 int pinctrl_count_index_with_args(const struct device_node *np, 349 const char *list_name) 350 { 351 const __be32 *list; 352 int size, nr_cells, error; 353 354 error = pinctrl_get_list_and_count(np, list_name, &list, 355 &nr_cells, &size); 356 if (error) 357 return error; 358 359 return size; 360 } 361 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args); 362 363 /** 364 * pinctrl_copy_args - Populates of_phandle_args based on index 365 * @np: pointer to device node with the property 366 * @list: pointer to a list with the elements 367 * @index: entry within the list of elements 368 * @nr_cells: number of cells in the list 369 * @nr_elem: number of elements for each entry in the list 370 * @out_args: returned values 371 * 372 * Populates the of_phandle_args based on the index in the list. 373 */ 374 static int pinctrl_copy_args(const struct device_node *np, 375 const __be32 *list, 376 int index, int nr_cells, int nr_elem, 377 struct of_phandle_args *out_args) 378 { 379 int i; 380 381 memset(out_args, 0, sizeof(*out_args)); 382 out_args->np = (struct device_node *)np; 383 out_args->args_count = nr_cells + 1; 384 385 if (index >= nr_elem) 386 return -EINVAL; 387 388 list += index * (nr_cells + 1); 389 390 for (i = 0; i < nr_cells + 1; i++) 391 out_args->args[i] = be32_to_cpup(list++); 392 393 return 0; 394 } 395 396 /** 397 * pinctrl_parse_index_with_args - Find a node pointed by index in a list 398 * @np: pointer to device node with the property 399 * @list_name: property that contains the list 400 * @index: index within the list 401 * @out_args: entries in the list pointed by index 402 * 403 * Finds the selected element in a pinctrl array consisting of an index 404 * within the controller and a number of u32 entries specified for each 405 * entry. Note that device_node is always for the parent pin controller device. 406 */ 407 int pinctrl_parse_index_with_args(const struct device_node *np, 408 const char *list_name, int index, 409 struct of_phandle_args *out_args) 410 { 411 const __be32 *list; 412 int nr_elem, nr_cells, error; 413 414 error = pinctrl_get_list_and_count(np, list_name, &list, 415 &nr_cells, &nr_elem); 416 if (error || !nr_cells) 417 return error; 418 419 error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem, 420 out_args); 421 if (error) 422 return error; 423 424 return 0; 425 } 426 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args); 427