tree_32.c 7.1 KB

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  1. // SPDX-License-Identifier: GPL-2.0
  2. /*
  3. * tree.c: Basic device tree traversal/scanning for the Linux
  4. * prom library.
  5. *
  6. * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
  7. */
  8. #include <linux/string.h>
  9. #include <linux/types.h>
  10. #include <linux/kernel.h>
  11. #include <linux/sched.h>
  12. #include <linux/ctype.h>
  13. #include <linux/module.h>
  14. #include <asm/openprom.h>
  15. #include <asm/oplib.h>
  16. extern void restore_current(void);
  17. static char promlib_buf[128];
  18. /* Internal version of prom_getchild that does not alter return values. */
  19. static phandle __prom_getchild(phandle node)
  20. {
  21. unsigned long flags;
  22. phandle cnode;
  23. spin_lock_irqsave(&prom_lock, flags);
  24. cnode = prom_nodeops->no_child(node);
  25. restore_current();
  26. spin_unlock_irqrestore(&prom_lock, flags);
  27. return cnode;
  28. }
  29. /* Return the child of node 'node' or zero if no this node has no
  30. * direct descendent.
  31. */
  32. phandle prom_getchild(phandle node)
  33. {
  34. phandle cnode;
  35. if ((s32)node == -1)
  36. return 0;
  37. cnode = __prom_getchild(node);
  38. if (cnode == 0 || (s32)cnode == -1)
  39. return 0;
  40. return cnode;
  41. }
  42. EXPORT_SYMBOL(prom_getchild);
  43. /* Internal version of prom_getsibling that does not alter return values. */
  44. static phandle __prom_getsibling(phandle node)
  45. {
  46. unsigned long flags;
  47. phandle cnode;
  48. spin_lock_irqsave(&prom_lock, flags);
  49. cnode = prom_nodeops->no_nextnode(node);
  50. restore_current();
  51. spin_unlock_irqrestore(&prom_lock, flags);
  52. return cnode;
  53. }
  54. /* Return the next sibling of node 'node' or zero if no more siblings
  55. * at this level of depth in the tree.
  56. */
  57. phandle prom_getsibling(phandle node)
  58. {
  59. phandle sibnode;
  60. if ((s32)node == -1)
  61. return 0;
  62. sibnode = __prom_getsibling(node);
  63. if (sibnode == 0 || (s32)sibnode == -1)
  64. return 0;
  65. return sibnode;
  66. }
  67. EXPORT_SYMBOL(prom_getsibling);
  68. /* Return the length in bytes of property 'prop' at node 'node'.
  69. * Return -1 on error.
  70. */
  71. int prom_getproplen(phandle node, const char *prop)
  72. {
  73. int ret;
  74. unsigned long flags;
  75. if((!node) || (!prop))
  76. return -1;
  77. spin_lock_irqsave(&prom_lock, flags);
  78. ret = prom_nodeops->no_proplen(node, prop);
  79. restore_current();
  80. spin_unlock_irqrestore(&prom_lock, flags);
  81. return ret;
  82. }
  83. EXPORT_SYMBOL(prom_getproplen);
  84. /* Acquire a property 'prop' at node 'node' and place it in
  85. * 'buffer' which has a size of 'bufsize'. If the acquisition
  86. * was successful the length will be returned, else -1 is returned.
  87. */
  88. int prom_getproperty(phandle node, const char *prop, char *buffer, int bufsize)
  89. {
  90. int plen, ret;
  91. unsigned long flags;
  92. plen = prom_getproplen(node, prop);
  93. if((plen > bufsize) || (plen == 0) || (plen == -1))
  94. return -1;
  95. /* Ok, things seem all right. */
  96. spin_lock_irqsave(&prom_lock, flags);
  97. ret = prom_nodeops->no_getprop(node, prop, buffer);
  98. restore_current();
  99. spin_unlock_irqrestore(&prom_lock, flags);
  100. return ret;
  101. }
  102. EXPORT_SYMBOL(prom_getproperty);
  103. /* Acquire an integer property and return its value. Returns -1
  104. * on failure.
  105. */
  106. int prom_getint(phandle node, char *prop)
  107. {
  108. static int intprop;
  109. if(prom_getproperty(node, prop, (char *) &intprop, sizeof(int)) != -1)
  110. return intprop;
  111. return -1;
  112. }
  113. EXPORT_SYMBOL(prom_getint);
  114. /* Acquire an integer property, upon error return the passed default
  115. * integer.
  116. */
  117. int prom_getintdefault(phandle node, char *property, int deflt)
  118. {
  119. int retval;
  120. retval = prom_getint(node, property);
  121. if(retval == -1) return deflt;
  122. return retval;
  123. }
  124. EXPORT_SYMBOL(prom_getintdefault);
  125. /* Acquire a boolean property, 1=TRUE 0=FALSE. */
  126. int prom_getbool(phandle node, char *prop)
  127. {
  128. int retval;
  129. retval = prom_getproplen(node, prop);
  130. if(retval == -1) return 0;
  131. return 1;
  132. }
  133. EXPORT_SYMBOL(prom_getbool);
  134. /* Acquire a property whose value is a string, returns a null
  135. * string on error. The char pointer is the user supplied string
  136. * buffer.
  137. */
  138. void prom_getstring(phandle node, char *prop, char *user_buf, int ubuf_size)
  139. {
  140. int len;
  141. len = prom_getproperty(node, prop, user_buf, ubuf_size);
  142. if(len != -1) return;
  143. user_buf[0] = 0;
  144. }
  145. EXPORT_SYMBOL(prom_getstring);
  146. /* Search siblings at 'node_start' for a node with name
  147. * 'nodename'. Return node if successful, zero if not.
  148. */
  149. phandle prom_searchsiblings(phandle node_start, char *nodename)
  150. {
  151. phandle thisnode;
  152. int error;
  153. for(thisnode = node_start; thisnode;
  154. thisnode=prom_getsibling(thisnode)) {
  155. error = prom_getproperty(thisnode, "name", promlib_buf,
  156. sizeof(promlib_buf));
  157. /* Should this ever happen? */
  158. if(error == -1) continue;
  159. if(strcmp(nodename, promlib_buf)==0) return thisnode;
  160. }
  161. return 0;
  162. }
  163. EXPORT_SYMBOL(prom_searchsiblings);
  164. /* Interal version of nextprop that does not alter return values. */
  165. static char *__prom_nextprop(phandle node, char * oprop)
  166. {
  167. unsigned long flags;
  168. char *prop;
  169. spin_lock_irqsave(&prom_lock, flags);
  170. prop = prom_nodeops->no_nextprop(node, oprop);
  171. restore_current();
  172. spin_unlock_irqrestore(&prom_lock, flags);
  173. return prop;
  174. }
  175. /* Return the property type string after property type 'oprop'
  176. * at node 'node' . Returns empty string if no more
  177. * property types for this node.
  178. */
  179. char *prom_nextprop(phandle node, char *oprop, char *buffer)
  180. {
  181. if (node == 0 || (s32)node == -1)
  182. return "";
  183. return __prom_nextprop(node, oprop);
  184. }
  185. EXPORT_SYMBOL(prom_nextprop);
  186. phandle prom_finddevice(char *name)
  187. {
  188. char nbuf[128];
  189. char *s = name, *d;
  190. phandle node = prom_root_node, node2;
  191. unsigned int which_io, phys_addr;
  192. struct linux_prom_registers reg[PROMREG_MAX];
  193. while (*s++) {
  194. if (!*s) return node; /* path '.../' is legal */
  195. node = prom_getchild(node);
  196. for (d = nbuf; *s != 0 && *s != '@' && *s != '/';)
  197. *d++ = *s++;
  198. *d = 0;
  199. node = prom_searchsiblings(node, nbuf);
  200. if (!node)
  201. return 0;
  202. if (*s == '@') {
  203. if (isxdigit(s[1]) && s[2] == ',') {
  204. which_io = simple_strtoul(s+1, NULL, 16);
  205. phys_addr = simple_strtoul(s+3, &d, 16);
  206. if (d != s + 3 && (!*d || *d == '/')
  207. && d <= s + 3 + 8) {
  208. node2 = node;
  209. while (node2 && (s32)node2 != -1) {
  210. if (prom_getproperty (node2, "reg", (char *)reg, sizeof (reg)) > 0) {
  211. if (which_io == reg[0].which_io && phys_addr == reg[0].phys_addr) {
  212. node = node2;
  213. break;
  214. }
  215. }
  216. node2 = prom_getsibling(node2);
  217. if (!node2 || (s32)node2 == -1)
  218. break;
  219. node2 = prom_searchsiblings(prom_getsibling(node2), nbuf);
  220. }
  221. }
  222. }
  223. while (*s != 0 && *s != '/') s++;
  224. }
  225. }
  226. return node;
  227. }
  228. EXPORT_SYMBOL(prom_finddevice);
  229. /* Set property 'pname' at node 'node' to value 'value' which has a length
  230. * of 'size' bytes. Return the number of bytes the prom accepted.
  231. */
  232. int prom_setprop(phandle node, const char *pname, char *value, int size)
  233. {
  234. unsigned long flags;
  235. int ret;
  236. if (size == 0)
  237. return 0;
  238. if ((pname == NULL) || (value == NULL))
  239. return 0;
  240. spin_lock_irqsave(&prom_lock, flags);
  241. ret = prom_nodeops->no_setprop(node, pname, value, size);
  242. restore_current();
  243. spin_unlock_irqrestore(&prom_lock, flags);
  244. return ret;
  245. }
  246. EXPORT_SYMBOL(prom_setprop);
  247. phandle prom_inst2pkg(int inst)
  248. {
  249. phandle node;
  250. unsigned long flags;
  251. spin_lock_irqsave(&prom_lock, flags);
  252. node = (*romvec->pv_v2devops.v2_inst2pkg)(inst);
  253. restore_current();
  254. spin_unlock_irqrestore(&prom_lock, flags);
  255. if ((s32)node == -1)
  256. return 0;
  257. return node;
  258. }