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