devicetree.c 11 KB

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  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. #include <linux/device.h>
  8. #include <linux/of.h>
  9. #include <linux/pinctrl/pinctrl.h>
  10. #include <linux/slab.h>
  11. #include "core.h"
  12. #include "devicetree.h"
  13. /**
  14. * struct pinctrl_dt_map - mapping table chunk parsed from device tree
  15. * @node: list node for struct pinctrl's @dt_maps field
  16. * @pctldev: the pin controller that allocated this struct, and will free it
  17. * @map: the mapping table entries
  18. * @num_maps: number of mapping table entries
  19. */
  20. struct pinctrl_dt_map {
  21. struct list_head node;
  22. struct pinctrl_dev *pctldev;
  23. struct pinctrl_map *map;
  24. unsigned num_maps;
  25. };
  26. static void dt_free_map(struct pinctrl_dev *pctldev,
  27. struct pinctrl_map *map, unsigned num_maps)
  28. {
  29. int i;
  30. for (i = 0; i < num_maps; ++i) {
  31. kfree_const(map[i].dev_name);
  32. map[i].dev_name = NULL;
  33. }
  34. if (pctldev) {
  35. const struct pinctrl_ops *ops = pctldev->desc->pctlops;
  36. if (ops->dt_free_map)
  37. ops->dt_free_map(pctldev, map, num_maps);
  38. } else {
  39. /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
  40. kfree(map);
  41. }
  42. }
  43. void pinctrl_dt_free_maps(struct pinctrl *p)
  44. {
  45. struct pinctrl_dt_map *dt_map, *n1;
  46. list_for_each_entry_safe(dt_map, n1, &p->dt_maps, node) {
  47. pinctrl_unregister_mappings(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. of_node_put(p->dev->of_node);
  54. }
  55. static int dt_remember_or_free_map(struct pinctrl *p, const char *statename,
  56. struct pinctrl_dev *pctldev,
  57. struct pinctrl_map *map, unsigned num_maps)
  58. {
  59. int i;
  60. struct pinctrl_dt_map *dt_map;
  61. /* Initialize common mapping table entry fields */
  62. for (i = 0; i < num_maps; i++) {
  63. const char *devname;
  64. devname = kstrdup_const(dev_name(p->dev), GFP_KERNEL);
  65. if (!devname)
  66. goto err_free_map;
  67. map[i].dev_name = devname;
  68. map[i].name = statename;
  69. if (pctldev)
  70. map[i].ctrl_dev_name = dev_name(pctldev->dev);
  71. }
  72. /* Remember the converted mapping table entries */
  73. dt_map = kzalloc(sizeof(*dt_map), GFP_KERNEL);
  74. if (!dt_map)
  75. goto err_free_map;
  76. dt_map->pctldev = pctldev;
  77. dt_map->map = map;
  78. dt_map->num_maps = num_maps;
  79. list_add_tail(&dt_map->node, &p->dt_maps);
  80. return pinctrl_register_mappings(map, num_maps);
  81. err_free_map:
  82. dt_free_map(pctldev, map, num_maps);
  83. return -ENOMEM;
  84. }
  85. struct pinctrl_dev *of_pinctrl_get(struct device_node *np)
  86. {
  87. return get_pinctrl_dev_from_of_node(np);
  88. }
  89. EXPORT_SYMBOL_GPL(of_pinctrl_get);
  90. static int dt_to_map_one_config(struct pinctrl *p,
  91. struct pinctrl_dev *hog_pctldev,
  92. const char *statename,
  93. struct device_node *np_config)
  94. {
  95. struct pinctrl_dev *pctldev = NULL;
  96. struct device_node *np_pctldev;
  97. const struct pinctrl_ops *ops;
  98. int ret;
  99. struct pinctrl_map *map;
  100. unsigned num_maps;
  101. bool allow_default = false;
  102. /* Find the pin controller containing np_config */
  103. np_pctldev = of_node_get(np_config);
  104. for (;;) {
  105. if (!allow_default)
  106. allow_default = of_property_read_bool(np_pctldev,
  107. "pinctrl-use-default");
  108. np_pctldev = of_get_next_parent(np_pctldev);
  109. if (!np_pctldev || of_node_is_root(np_pctldev)) {
  110. of_node_put(np_pctldev);
  111. ret = driver_deferred_probe_check_state(p->dev);
  112. /* keep deferring if modules are enabled */
  113. if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret < 0)
  114. ret = -EPROBE_DEFER;
  115. return ret;
  116. }
  117. /* If we're creating a hog we can use the passed pctldev */
  118. if (hog_pctldev && (np_pctldev == p->dev->of_node)) {
  119. pctldev = hog_pctldev;
  120. break;
  121. }
  122. pctldev = get_pinctrl_dev_from_of_node(np_pctldev);
  123. if (pctldev)
  124. break;
  125. /* Do not defer probing of hogs (circular loop) */
  126. if (np_pctldev == p->dev->of_node) {
  127. of_node_put(np_pctldev);
  128. return -ENODEV;
  129. }
  130. }
  131. of_node_put(np_pctldev);
  132. /*
  133. * Call pinctrl driver to parse device tree node, and
  134. * generate mapping table entries
  135. */
  136. ops = pctldev->desc->pctlops;
  137. if (!ops->dt_node_to_map) {
  138. dev_err(p->dev, "pctldev %s doesn't support DT\n",
  139. dev_name(pctldev->dev));
  140. return -ENODEV;
  141. }
  142. ret = ops->dt_node_to_map(pctldev, np_config, &map, &num_maps);
  143. if (ret < 0)
  144. return ret;
  145. else if (num_maps == 0) {
  146. /*
  147. * If we have no valid maps (maybe caused by empty pinctrl node
  148. * or typing error) ther is no need remember this, so just
  149. * return.
  150. */
  151. dev_info(p->dev,
  152. "there is not valid maps for state %s\n", statename);
  153. return 0;
  154. }
  155. /* Stash the mapping table chunk away for later use */
  156. return dt_remember_or_free_map(p, statename, pctldev, map, num_maps);
  157. }
  158. static int dt_remember_dummy_state(struct pinctrl *p, const char *statename)
  159. {
  160. struct pinctrl_map *map;
  161. map = kzalloc(sizeof(*map), GFP_KERNEL);
  162. if (!map)
  163. return -ENOMEM;
  164. /* There is no pctldev for PIN_MAP_TYPE_DUMMY_STATE */
  165. map->type = PIN_MAP_TYPE_DUMMY_STATE;
  166. return dt_remember_or_free_map(p, statename, NULL, map, 1);
  167. }
  168. int pinctrl_dt_to_map(struct pinctrl *p, struct pinctrl_dev *pctldev)
  169. {
  170. struct device_node *np = p->dev->of_node;
  171. int state, ret;
  172. char *propname;
  173. struct property *prop;
  174. const char *statename;
  175. const __be32 *list;
  176. int size, config;
  177. phandle phandle;
  178. struct device_node *np_config;
  179. /* CONFIG_OF enabled, p->dev not instantiated from DT */
  180. if (!np) {
  181. if (of_have_populated_dt())
  182. dev_dbg(p->dev,
  183. "no of_node; not parsing pinctrl DT\n");
  184. return 0;
  185. }
  186. /* We may store pointers to property names within the node */
  187. of_node_get(np);
  188. /* For each defined state ID */
  189. for (state = 0; ; state++) {
  190. /* Retrieve the pinctrl-* property */
  191. propname = kasprintf(GFP_KERNEL, "pinctrl-%d", state);
  192. prop = of_find_property(np, propname, &size);
  193. kfree(propname);
  194. if (!prop) {
  195. if (state == 0) {
  196. of_node_put(np);
  197. return -ENODEV;
  198. }
  199. break;
  200. }
  201. list = prop->value;
  202. size /= sizeof(*list);
  203. /* Determine whether pinctrl-names property names the state */
  204. ret = of_property_read_string_index(np, "pinctrl-names",
  205. state, &statename);
  206. /*
  207. * If not, statename is just the integer state ID. But rather
  208. * than dynamically allocate it and have to free it later,
  209. * just point part way into the property name for the string.
  210. */
  211. if (ret < 0)
  212. statename = prop->name + strlen("pinctrl-");
  213. /* For every referenced pin configuration node in it */
  214. for (config = 0; config < size; config++) {
  215. phandle = be32_to_cpup(list++);
  216. /* Look up the pin configuration node */
  217. np_config = of_find_node_by_phandle(phandle);
  218. if (!np_config) {
  219. dev_err(p->dev,
  220. "prop %s index %i invalid phandle\n",
  221. prop->name, config);
  222. ret = -EINVAL;
  223. goto err;
  224. }
  225. /* Parse the node */
  226. ret = dt_to_map_one_config(p, pctldev, statename,
  227. np_config);
  228. of_node_put(np_config);
  229. if (ret < 0)
  230. goto err;
  231. }
  232. /* No entries in DT? Generate a dummy state table entry */
  233. if (!size) {
  234. ret = dt_remember_dummy_state(p, statename);
  235. if (ret < 0)
  236. goto err;
  237. }
  238. }
  239. return 0;
  240. err:
  241. pinctrl_dt_free_maps(p);
  242. return ret;
  243. }
  244. /*
  245. * For pinctrl binding, typically #pinctrl-cells is for the pin controller
  246. * device, so either parent or grandparent. See pinctrl-bindings.txt.
  247. */
  248. static int pinctrl_find_cells_size(const struct device_node *np)
  249. {
  250. const char *cells_name = "#pinctrl-cells";
  251. int cells_size, error;
  252. error = of_property_read_u32(np->parent, cells_name, &cells_size);
  253. if (error) {
  254. error = of_property_read_u32(np->parent->parent,
  255. cells_name, &cells_size);
  256. if (error)
  257. return -ENOENT;
  258. }
  259. return cells_size;
  260. }
  261. /**
  262. * pinctrl_get_list_and_count - Gets the list and it's cell size and number
  263. * @np: pointer to device node with the property
  264. * @list_name: property that contains the list
  265. * @list: pointer for the list found
  266. * @cells_size: pointer for the cell size found
  267. * @nr_elements: pointer for the number of elements found
  268. *
  269. * Typically np is a single pinctrl entry containing the list.
  270. */
  271. static int pinctrl_get_list_and_count(const struct device_node *np,
  272. const char *list_name,
  273. const __be32 **list,
  274. int *cells_size,
  275. int *nr_elements)
  276. {
  277. int size;
  278. *cells_size = 0;
  279. *nr_elements = 0;
  280. *list = of_get_property(np, list_name, &size);
  281. if (!*list)
  282. return -ENOENT;
  283. *cells_size = pinctrl_find_cells_size(np);
  284. if (*cells_size < 0)
  285. return -ENOENT;
  286. /* First element is always the index within the pinctrl device */
  287. *nr_elements = (size / sizeof(**list)) / (*cells_size + 1);
  288. return 0;
  289. }
  290. /**
  291. * pinctrl_count_index_with_args - Count number of elements in a pinctrl entry
  292. * @np: pointer to device node with the property
  293. * @list_name: property that contains the list
  294. *
  295. * Counts the number of elements in a pinctrl array consisting of an index
  296. * within the controller and a number of u32 entries specified for each
  297. * entry. Note that device_node is always for the parent pin controller device.
  298. */
  299. int pinctrl_count_index_with_args(const struct device_node *np,
  300. const char *list_name)
  301. {
  302. const __be32 *list;
  303. int size, nr_cells, error;
  304. error = pinctrl_get_list_and_count(np, list_name, &list,
  305. &nr_cells, &size);
  306. if (error)
  307. return error;
  308. return size;
  309. }
  310. EXPORT_SYMBOL_GPL(pinctrl_count_index_with_args);
  311. /**
  312. * pinctrl_copy_args - Populates of_phandle_args based on index
  313. * @np: pointer to device node with the property
  314. * @list: pointer to a list with the elements
  315. * @index: entry within the list of elements
  316. * @nr_cells: number of cells in the list
  317. * @nr_elem: number of elements for each entry in the list
  318. * @out_args: returned values
  319. *
  320. * Populates the of_phandle_args based on the index in the list.
  321. */
  322. static int pinctrl_copy_args(const struct device_node *np,
  323. const __be32 *list,
  324. int index, int nr_cells, int nr_elem,
  325. struct of_phandle_args *out_args)
  326. {
  327. int i;
  328. memset(out_args, 0, sizeof(*out_args));
  329. out_args->np = (struct device_node *)np;
  330. out_args->args_count = nr_cells + 1;
  331. if (index >= nr_elem)
  332. return -EINVAL;
  333. list += index * (nr_cells + 1);
  334. for (i = 0; i < nr_cells + 1; i++)
  335. out_args->args[i] = be32_to_cpup(list++);
  336. return 0;
  337. }
  338. /**
  339. * pinctrl_parse_index_with_args - Find a node pointed by index in a list
  340. * @np: pointer to device node with the property
  341. * @list_name: property that contains the list
  342. * @index: index within the list
  343. * @out_args: entries in the list pointed by index
  344. *
  345. * Finds the selected element in a pinctrl array consisting of an index
  346. * within the controller and a number of u32 entries specified for each
  347. * entry. Note that device_node is always for the parent pin controller device.
  348. */
  349. int pinctrl_parse_index_with_args(const struct device_node *np,
  350. const char *list_name, int index,
  351. struct of_phandle_args *out_args)
  352. {
  353. const __be32 *list;
  354. int nr_elem, nr_cells, error;
  355. error = pinctrl_get_list_and_count(np, list_name, &list,
  356. &nr_cells, &nr_elem);
  357. if (error || !nr_cells)
  358. return error;
  359. error = pinctrl_copy_args(np, list, index, nr_cells, nr_elem,
  360. out_args);
  361. if (error)
  362. return error;
  363. return 0;
  364. }
  365. EXPORT_SYMBOL_GPL(pinctrl_parse_index_with_args);