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 if (pctldev) { 33 const struct pinctrl_ops *ops = pctldev->desc->pctlops; 34 if (ops->dt_free_map) 35 ops->dt_free_map(pctldev, map, num_maps); 36 } else { 37 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ 38 kfree(map); 39 } 40 } 41 42 void pinctrl_dt_free_maps(struct pinctrl *p) 43 { 44 struct pinctrl_dt_map *dt_map, *n1; 45 46 list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) { 47 pinctrl_unregister_map(dt_map->map); 48 list_del(&dt_map->node); 49 dt_free_map(dt_map->pctldev, dt_map->map, 50 dt_map->num_maps); 51 kfree(dt_map); 52 } 53 54 of_node_put(p->dev->of_node); 55 } 56 57 static int dt_remember_or_free_map(struct pinctrl *p, const char *statename, 58 struct pinctrl_dev *pctldev, 59 struct pinctrl_map *map, unsigned num_maps) 60 { 61 int i; 62 struct pinctrl_dt_map *dt_map; 63 64 /* Initialize common mapping table entry fields */ 65 for (i = 0; i < num_maps; i++) { 66 map[i].dev_name = dev_name(p->dev); 67 map[i].name = statename; 68 if (pctldev) 69 map[i].ctrl_dev_name = dev_name(pctldev->dev); 70 } 71 72 /* Remember the converted mapping table entries */ 73 dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL); 74 if (!dt_map) { 75 dt_free_map(pctldev, map, num_maps); 76 return -ENOMEM; 77 } 78 79 dt_map->pctldev = pctldev; 80 dt_map->map = map; 81 dt_map->num_maps = num_maps; 82 list_add_tail(&dt_map->node, &p->dt_maps); 83 84 return pinctrl_register_map(map, num_maps, false); 85 } 86 87 struct pinctrl_dev *of_pinctrl_get(struct device_node *np) 88 { 89 return get_pinctrl_dev_from_of_node(np); 90 } 91 92 static int dt_to_map_one_config(struct pinctrl *p, 93 struct pinctrl_dev *hog_pctldev, 94 const char *statename, 95 struct device_node *np_config) 96 { 97 struct pinctrl_dev *pctldev = NULL; 98 struct device_node *np_pctldev; 99 const struct pinctrl_ops *ops; 100 int ret; 101 struct pinctrl_map *map; 102 unsigned num_maps; 103 bool allow_default = false; 104 105 /* Find the pin controller containing np_config */ 106 np_pctldev = of_node_get(np_config); 107 for (;;) { 108 if (!allow_default) 109 allow_default = of_property_read_bool(np_pctldev, 110 "pinctrl-use-default"); 111 112 np_pctldev = of_get_next_parent(np_pctldev); 113 if (!np_pctldev || of_node_is_root(np_pctldev)) { 114 of_node_put(np_pctldev); 115 ret = driver_deferred_probe_check_state(p->dev); 116 /* keep deferring if modules are enabled unless we've timed out */ 117 if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret == -ENODEV) 118 ret = -EPROBE_DEFER; 119 120 return ret; 121 } 122 /* If we're creating a hog we can use the passed pctldev */ 123 if (hog_pctldev && (np_pctldev == p->dev->of_node)) { 124 pctldev = hog_pctldev; 125 break; 126 } 127 pctldev = get_pinctrl_dev_from_of_node(np_pctldev); 128 if (pctldev) 129 break; 130 /* Do not defer probing of hogs (circular loop) */ 131 if (np_pctldev == p->dev->of_node) { 132 of_node_put(np_pctldev); 133 return -ENODEV; 134 } 135 } 136 of_node_put(np_pctldev); 137 138 /* 139 * Call pinctrl driver to parse device tree node, and 140 * generate mapping table entries 141 */ 142 ops = pctldev->desc->pctlops; 143 if (!ops->dt_node_to_map) { 144 dev_err(p->dev, "pctldev %s doesn't support DT\n", 145 dev_name(pctldev->dev)); 146 return -ENODEV; 147 } 148 ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps); 149 if (ret < 0) 150 return ret; 151 152 /* Stash the mapping table chunk away for later use */ 153 return dt_remember_or_free_map(p, statename, pctldev, map, num_maps); 154 } 155 156 static int dt_remember_dummy_state(struct pinctrl *p, const char *statename) 157 { 158 struct pinctrl_map *map; 159 160 map = kzalloc(sizeof(*map), GFP_KERNEL); 161 if (!map) 162 return -ENOMEM; 163 164 /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */ 165 map->type = PIN_MAP_TYPE_DUMMY_STATE; 166 167 return dt_remember_or_free_map(p, statename, NULL, map, 1); 168 } 169 170 bool pinctrl_dt_has_hogs(struct pinctrl_dev *pctldev) 171 { 172 struct device_node *np; 173 struct property *prop; 174 int size; 175 176 np = pctldev->dev->of_node; 177 if (!np) 178 return false; 179 180 prop = of_find_property(np, "pinctrl-0", &size); 181 182 return prop ? true : false; 183 } 184 185 int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev) 186 { 187 struct device_node *np = p->dev->of_node; 188 int state, ret; 189 char *propname; 190 struct property *prop; 191 const char *statename; 192 const __be32 *list; 193 int size, config; 194 phandle phandle; 195 struct device_node *np_config; 196 197 /* CONFIG_OF enabled, p->dev not instantiated from DT */ 198 if (!np) { 199 if (of_have_populated_dt()) 200 dev_dbg(p->dev, 201 "no of_node; not parsing pinctrl DT\n"); 202 return 0; 203 } 204 205 /* We may store pointers to property names within the node */ 206 of_node_get(np); 207 208 /* For each defined state ID */ 209 for (state = 0; ; state++) { 210 /* Retrieve the pinctrl-* property */ 211 propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state); 212 prop = of_find_property(np, propname, &size); 213 kfree(propname); 214 if (!prop) { 215 if (state == 0) { 216 of_node_put(np); 217 return -ENODEV; 218 } 219 break; 220 } 221 list = prop->value; 222 size /= sizeof(*list); 223 224 /* Determine whether pinctrl-names property names the state */ 225 ret = of_property_read_string_index(np, "pinctrl-names", 226 state, &statename); 227 /* 228 * If not, statename is just the integer state ID. But rather 229 * than dynamically allocate it and have to free it later, 230 * just point part way into the property name for the string. 231 */ 232 if (ret < 0) { 233 /* strlen("pinctrl-") == 8 */ 234 statename = prop->name + 8; 235 } 236 237 /* For every referenced pin configuration node in it */ 238 for (config = 0; config < size; config++) { 239 phandle = be32_to_cpup(list++); 240 241 /* Look up the pin configuration node */ 242 np_config = of_find_node_by_phandle(phandle); 243 if (!np_config) { 244 dev_err(p->dev, 245 "prop %s index %i invalid phandle\n", 246 prop->name, config); 247 ret = -EINVAL; 248 goto err; 249 } 250 251 /* Parse the node */ 252 ret = dt_to_map_one_config(p, pctldev, statename, 253 np_config); 254 of_node_put(np_config); 255 if (ret < 0) 256 goto err; 257 } 258 259 /* No entries in DT? Generate a dummy state table entry */ 260 if (!size) { 261 ret = dt_remember_dummy_state(p, statename); 262 if (ret < 0) 263 goto err; 264 } 265 } 266 267 return 0; 268 269 err: 270 pinctrl_dt_free_maps(p); 271 return ret; 272 } 273 274 /* 275 * For pinctrl binding, typically #pinctrl-cells is for the pin controller 276 * device, so either parent or grandparent. See pinctrl-bindings.txt. 277 */ 278 static int pinctrl_find_cells_size(const struct device_node *np) 279 { 280 const char *cells_name = "#pinctrl-cells"; 281 int cells_size, error; 282 283 error = of_property_read_u32(np->parent, cells_name, &cells_size); 284 if (error) { 285 error = of_property_read_u32(np->parent->parent, 286 cells_name, &cells_size); 287 if (error) 288 return -ENOENT; 289 } 290 291 return cells_size; 292 } 293 294 /** 295 * pinctrl_get_list_and_count - Gets the list and it's cell size and number 296 * @np: pointer to device node with the property 297 * @list_name: property that contains the list 298 * @list: pointer for the list found 299 * @cells_size: pointer for the cell size found 300 * @nr_elements: pointer for the number of elements found 301 * 302 * Typically np is a single pinctrl entry containing the list. 303 */ 304 static int pinctrl_get_list_and_count(const struct device_node *np, 305 const char *list_name, 306 const __be32 **list, 307 int *cells_size, 308 int *nr_elements) 309 { 310 int size; 311 312 *cells_size = 0; 313 *nr_elements = 0; 314 315 *list = of_get_property(np, list_name, &size); 316 if (!*list) 317 return -ENOENT; 318 319 *cells_size = pinctrl_find_cells_size(np); 320 if (*cells_size < 0) 321 return -ENOENT; 322 323 /* First element is always the index within the pinctrl device */ 324 *nr_elements = (size / sizeof(**list)) / (*cells_size + 1); 325 326 return 0; 327 } 328 329 /** 330 * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry 331 * @np: pointer to device node with the property 332 * @list_name: property that contains the list 333 * 334 * Counts the number of elements in a pinctrl array consisting of an index 335 * within the controller and a number of u32 entries specified for each 336 * entry. Note that device_node is always for the parent pin controller device. 337 */ 338 int pinctrl_count_index_with_args(const struct device_node *np, 339 const char *list_name) 340 { 341 const __be32 *list; 342 int size, nr_cells, error; 343 344 error = pinctrl_get_list_and_count(np, list_name, &list, 345 &nr_cells, &size); 346 if (error) 347 return error; 348 349 return size; 350 } 351 EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args); 352 353 /** 354 * pinctrl_copy_args - Populates of_phandle_args based on index 355 * @np: pointer to device node with the property 356 * @list: pointer to a list with the elements 357 * @index: entry within the list of elements 358 * @nr_cells: number of cells in the list 359 * @nr_elem: number of elements for each entry in the list 360 * @out_args: returned values 361 * 362 * Populates the of_phandle_args based on the index in the list. 363 */ 364 static int pinctrl_copy_args(const struct device_node *np, 365 const __be32 *list, 366 int index, int nr_cells, int nr_elem, 367 struct of_phandle_args *out_args) 368 { 369 int i; 370 371 memset(out_args, 0, sizeof(*out_args)); 372 out_args->np = (struct device_node *)np; 373 out_args->args_count = nr_cells + 1; 374 375 if (index >= nr_elem) 376 return -EINVAL; 377 378 list += index * (nr_cells + 1); 379 380 for (i = 0; i < nr_cells + 1; i++) 381 out_args->args[i] = be32_to_cpup(list++); 382 383 return 0; 384 } 385 386 /** 387 * pinctrl_parse_index_with_args - Find a node pointed by index in a list 388 * @np: pointer to device node with the property 389 * @list_name: property that contains the list 390 * @index: index within the list 391 * @out_arts: entries in the list pointed by index 392 * 393 * Finds the selected element in a pinctrl array consisting of an index 394 * within the controller and a number of u32 entries specified for each 395 * entry. Note that device_node is always for the parent pin controller device. 396 */ 397 int pinctrl_parse_index_with_args(const struct device_node *np, 398 const char *list_name, int index, 399 struct of_phandle_args *out_args) 400 { 401 const __be32 *list; 402 int nr_elem, nr_cells, error; 403 404 error = pinctrl_get_list_and_count(np, list_name, &list, 405 &nr_cells, &nr_elem); 406 if (error || !nr_cells) 407 return error; 408 409 error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem, 410 out_args); 411 if (error) 412 return error; 413 414 return 0; 415 } 416 EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args); 417