1 /* 2 * tree.c: Basic device tree traversal/scanning for the Linux 3 * prom library. 4 * 5 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) 6 */ 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 15 #include <asm/openprom.h> 16 #include <asm/oplib.h> 17 18 extern void restore_current(void); 19 20 static char promlib_buf[128]; 21 22 /* Internal version of prom_getchild that does not alter return values. */ 23 int __prom_getchild(int node) 24 { 25 unsigned long flags; 26 int cnode; 27 28 spin_lock_irqsave(&prom_lock, flags); 29 cnode = prom_nodeops->no_child(node); 30 restore_current(); 31 spin_unlock_irqrestore(&prom_lock, flags); 32 33 return cnode; 34 } 35 36 /* Return the child of node 'node' or zero if no this node has no 37 * direct descendent. 38 */ 39 int prom_getchild(int node) 40 { 41 int cnode; 42 43 if (node == -1) 44 return 0; 45 46 cnode = __prom_getchild(node); 47 if (cnode == 0 || cnode == -1) 48 return 0; 49 50 return cnode; 51 } 52 EXPORT_SYMBOL(prom_getchild); 53 54 /* Internal version of prom_getsibling that does not alter return values. */ 55 int __prom_getsibling(int node) 56 { 57 unsigned long flags; 58 int cnode; 59 60 spin_lock_irqsave(&prom_lock, flags); 61 cnode = prom_nodeops->no_nextnode(node); 62 restore_current(); 63 spin_unlock_irqrestore(&prom_lock, flags); 64 65 return cnode; 66 } 67 68 /* Return the next sibling of node 'node' or zero if no more siblings 69 * at this level of depth in the tree. 70 */ 71 int prom_getsibling(int node) 72 { 73 int sibnode; 74 75 if (node == -1) 76 return 0; 77 78 sibnode = __prom_getsibling(node); 79 if (sibnode == 0 || sibnode == -1) 80 return 0; 81 82 return sibnode; 83 } 84 EXPORT_SYMBOL(prom_getsibling); 85 86 /* Return the length in bytes of property 'prop' at node 'node'. 87 * Return -1 on error. 88 */ 89 int prom_getproplen(int node, const char *prop) 90 { 91 int ret; 92 unsigned long flags; 93 94 if((!node) || (!prop)) 95 return -1; 96 97 spin_lock_irqsave(&prom_lock, flags); 98 ret = prom_nodeops->no_proplen(node, prop); 99 restore_current(); 100 spin_unlock_irqrestore(&prom_lock, flags); 101 return ret; 102 } 103 EXPORT_SYMBOL(prom_getproplen); 104 105 /* Acquire a property 'prop' at node 'node' and place it in 106 * 'buffer' which has a size of 'bufsize'. If the acquisition 107 * was successful the length will be returned, else -1 is returned. 108 */ 109 int prom_getproperty(int node, const char *prop, char *buffer, int bufsize) 110 { 111 int plen, ret; 112 unsigned long flags; 113 114 plen = prom_getproplen(node, prop); 115 if((plen > bufsize) || (plen == 0) || (plen == -1)) 116 return -1; 117 /* Ok, things seem all right. */ 118 spin_lock_irqsave(&prom_lock, flags); 119 ret = prom_nodeops->no_getprop(node, prop, buffer); 120 restore_current(); 121 spin_unlock_irqrestore(&prom_lock, flags); 122 return ret; 123 } 124 EXPORT_SYMBOL(prom_getproperty); 125 126 /* Acquire an integer property and return its value. Returns -1 127 * on failure. 128 */ 129 int prom_getint(int node, char *prop) 130 { 131 static int intprop; 132 133 if(prom_getproperty(node, prop, (char *) &intprop, sizeof(int)) != -1) 134 return intprop; 135 136 return -1; 137 } 138 EXPORT_SYMBOL(prom_getint); 139 140 /* Acquire an integer property, upon error return the passed default 141 * integer. 142 */ 143 int prom_getintdefault(int node, char *property, int deflt) 144 { 145 int retval; 146 147 retval = prom_getint(node, property); 148 if(retval == -1) return deflt; 149 150 return retval; 151 } 152 EXPORT_SYMBOL(prom_getintdefault); 153 154 /* Acquire a boolean property, 1=TRUE 0=FALSE. */ 155 int prom_getbool(int node, char *prop) 156 { 157 int retval; 158 159 retval = prom_getproplen(node, prop); 160 if(retval == -1) return 0; 161 return 1; 162 } 163 EXPORT_SYMBOL(prom_getbool); 164 165 /* Acquire a property whose value is a string, returns a null 166 * string on error. The char pointer is the user supplied string 167 * buffer. 168 */ 169 void prom_getstring(int node, char *prop, char *user_buf, int ubuf_size) 170 { 171 int len; 172 173 len = prom_getproperty(node, prop, user_buf, ubuf_size); 174 if(len != -1) return; 175 user_buf[0] = 0; 176 } 177 EXPORT_SYMBOL(prom_getstring); 178 179 180 /* Does the device at node 'node' have name 'name'? 181 * YES = 1 NO = 0 182 */ 183 int prom_nodematch(int node, char *name) 184 { 185 int error; 186 187 static char namebuf[128]; 188 error = prom_getproperty(node, "name", namebuf, sizeof(namebuf)); 189 if (error == -1) return 0; 190 if(strcmp(namebuf, name) == 0) return 1; 191 return 0; 192 } 193 194 /* Search siblings at 'node_start' for a node with name 195 * 'nodename'. Return node if successful, zero if not. 196 */ 197 int prom_searchsiblings(int node_start, char *nodename) 198 { 199 200 int thisnode, error; 201 202 for(thisnode = node_start; thisnode; 203 thisnode=prom_getsibling(thisnode)) { 204 error = prom_getproperty(thisnode, "name", promlib_buf, 205 sizeof(promlib_buf)); 206 /* Should this ever happen? */ 207 if(error == -1) continue; 208 if(strcmp(nodename, promlib_buf)==0) return thisnode; 209 } 210 211 return 0; 212 } 213 EXPORT_SYMBOL(prom_searchsiblings); 214 215 /* Interal version of nextprop that does not alter return values. */ 216 char * __prom_nextprop(int node, char * oprop) 217 { 218 unsigned long flags; 219 char *prop; 220 221 spin_lock_irqsave(&prom_lock, flags); 222 prop = prom_nodeops->no_nextprop(node, oprop); 223 restore_current(); 224 spin_unlock_irqrestore(&prom_lock, flags); 225 226 return prop; 227 } 228 229 /* Return the first property name for node 'node'. */ 230 /* buffer is unused argument, but as v9 uses it, we need to have the same interface */ 231 char * prom_firstprop(int node, char *bufer) 232 { 233 if (node == 0 || node == -1) 234 return ""; 235 236 return __prom_nextprop(node, ""); 237 } 238 EXPORT_SYMBOL(prom_firstprop); 239 240 /* Return the property type string after property type 'oprop' 241 * at node 'node' . Returns empty string if no more 242 * property types for this node. 243 */ 244 char * prom_nextprop(int node, char *oprop, char *buffer) 245 { 246 if (node == 0 || node == -1) 247 return ""; 248 249 return __prom_nextprop(node, oprop); 250 } 251 EXPORT_SYMBOL(prom_nextprop); 252 253 int prom_finddevice(char *name) 254 { 255 char nbuf[128]; 256 char *s = name, *d; 257 int node = prom_root_node, node2; 258 unsigned int which_io, phys_addr; 259 struct linux_prom_registers reg[PROMREG_MAX]; 260 261 while (*s++) { 262 if (!*s) return node; /* path '.../' is legal */ 263 node = prom_getchild(node); 264 265 for (d = nbuf; *s != 0 && *s != '@' && *s != '/';) 266 *d++ = *s++; 267 *d = 0; 268 269 node = prom_searchsiblings(node, nbuf); 270 if (!node) 271 return 0; 272 273 if (*s == '@') { 274 if (isxdigit(s[1]) && s[2] == ',') { 275 which_io = simple_strtoul(s+1, NULL, 16); 276 phys_addr = simple_strtoul(s+3, &d, 16); 277 if (d != s + 3 && (!*d || *d == '/') 278 && d <= s + 3 + 8) { 279 node2 = node; 280 while (node2 && node2 != -1) { 281 if (prom_getproperty (node2, "reg", (char *)reg, sizeof (reg)) > 0) { 282 if (which_io == reg[0].which_io && phys_addr == reg[0].phys_addr) { 283 node = node2; 284 break; 285 } 286 } 287 node2 = prom_getsibling(node2); 288 if (!node2 || node2 == -1) 289 break; 290 node2 = prom_searchsiblings(prom_getsibling(node2), nbuf); 291 } 292 } 293 } 294 while (*s != 0 && *s != '/') s++; 295 } 296 } 297 return node; 298 } 299 EXPORT_SYMBOL(prom_finddevice); 300 301 int prom_node_has_property(int node, char *prop) 302 { 303 char *current_property = ""; 304 305 do { 306 current_property = prom_nextprop(node, current_property, NULL); 307 if(!strcmp(current_property, prop)) 308 return 1; 309 } while (*current_property); 310 return 0; 311 } 312 EXPORT_SYMBOL(prom_node_has_property); 313 314 /* Set property 'pname' at node 'node' to value 'value' which has a length 315 * of 'size' bytes. Return the number of bytes the prom accepted. 316 */ 317 int prom_setprop(int node, const char *pname, char *value, int size) 318 { 319 unsigned long flags; 320 int ret; 321 322 if(size == 0) return 0; 323 if((pname == 0) || (value == 0)) return 0; 324 spin_lock_irqsave(&prom_lock, flags); 325 ret = prom_nodeops->no_setprop(node, pname, value, size); 326 restore_current(); 327 spin_unlock_irqrestore(&prom_lock, flags); 328 return ret; 329 } 330 EXPORT_SYMBOL(prom_setprop); 331 332 int prom_inst2pkg(int inst) 333 { 334 int node; 335 unsigned long flags; 336 337 spin_lock_irqsave(&prom_lock, flags); 338 node = (*romvec->pv_v2devops.v2_inst2pkg)(inst); 339 restore_current(); 340 spin_unlock_irqrestore(&prom_lock, flags); 341 if (node == -1) return 0; 342 return node; 343 } 344 345 /* Return 'node' assigned to a particular prom 'path' 346 * FIXME: Should work for v0 as well 347 */ 348 int prom_pathtoinode(char *path) 349 { 350 int node, inst; 351 352 inst = prom_devopen (path); 353 if (inst == -1) return 0; 354 node = prom_inst2pkg (inst); 355 prom_devclose (inst); 356 if (node == -1) return 0; 357 return node; 358 } 359