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 static phandle __prom_getchild(phandle node) 24 { 25 unsigned long flags; 26 phandle 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 phandle prom_getchild(phandle node) 40 { 41 phandle cnode; 42 43 if ((s32)node == -1) 44 return 0; 45 46 cnode = __prom_getchild(node); 47 if (cnode == 0 || (s32)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 static phandle __prom_getsibling(phandle node) 56 { 57 unsigned long flags; 58 phandle 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 phandle prom_getsibling(phandle node) 72 { 73 phandle sibnode; 74 75 if ((s32)node == -1) 76 return 0; 77 78 sibnode = __prom_getsibling(node); 79 if (sibnode == 0 || (s32)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(phandle 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(phandle 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(phandle 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(phandle 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(phandle 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(phandle 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 /* Search siblings at 'node_start' for a node with name 181 * 'nodename'. Return node if successful, zero if not. 182 */ 183 phandle prom_searchsiblings(phandle node_start, char *nodename) 184 { 185 186 phandle thisnode; 187 int error; 188 189 for(thisnode = node_start; thisnode; 190 thisnode=prom_getsibling(thisnode)) { 191 error = prom_getproperty(thisnode, "name", promlib_buf, 192 sizeof(promlib_buf)); 193 /* Should this ever happen? */ 194 if(error == -1) continue; 195 if(strcmp(nodename, promlib_buf)==0) return thisnode; 196 } 197 198 return 0; 199 } 200 EXPORT_SYMBOL(prom_searchsiblings); 201 202 /* Interal version of nextprop that does not alter return values. */ 203 static char *__prom_nextprop(phandle node, char * oprop) 204 { 205 unsigned long flags; 206 char *prop; 207 208 spin_lock_irqsave(&prom_lock, flags); 209 prop = prom_nodeops->no_nextprop(node, oprop); 210 restore_current(); 211 spin_unlock_irqrestore(&prom_lock, flags); 212 213 return prop; 214 } 215 216 /* Return the property type string after property type 'oprop' 217 * at node 'node' . Returns empty string if no more 218 * property types for this node. 219 */ 220 char *prom_nextprop(phandle node, char *oprop, char *buffer) 221 { 222 if (node == 0 || (s32)node == -1) 223 return ""; 224 225 return __prom_nextprop(node, oprop); 226 } 227 EXPORT_SYMBOL(prom_nextprop); 228 229 phandle prom_finddevice(char *name) 230 { 231 char nbuf[128]; 232 char *s = name, *d; 233 phandle node = prom_root_node, node2; 234 unsigned int which_io, phys_addr; 235 struct linux_prom_registers reg[PROMREG_MAX]; 236 237 while (*s++) { 238 if (!*s) return node; /* path '.../' is legal */ 239 node = prom_getchild(node); 240 241 for (d = nbuf; *s != 0 && *s != '@' && *s != '/';) 242 *d++ = *s++; 243 *d = 0; 244 245 node = prom_searchsiblings(node, nbuf); 246 if (!node) 247 return 0; 248 249 if (*s == '@') { 250 if (isxdigit(s[1]) && s[2] == ',') { 251 which_io = simple_strtoul(s+1, NULL, 16); 252 phys_addr = simple_strtoul(s+3, &d, 16); 253 if (d != s + 3 && (!*d || *d == '/') 254 && d <= s + 3 + 8) { 255 node2 = node; 256 while (node2 && (s32)node2 != -1) { 257 if (prom_getproperty (node2, "reg", (char *)reg, sizeof (reg)) > 0) { 258 if (which_io == reg[0].which_io && phys_addr == reg[0].phys_addr) { 259 node = node2; 260 break; 261 } 262 } 263 node2 = prom_getsibling(node2); 264 if (!node2 || (s32)node2 == -1) 265 break; 266 node2 = prom_searchsiblings(prom_getsibling(node2), nbuf); 267 } 268 } 269 } 270 while (*s != 0 && *s != '/') s++; 271 } 272 } 273 return node; 274 } 275 EXPORT_SYMBOL(prom_finddevice); 276 277 /* Set property 'pname' at node 'node' to value 'value' which has a length 278 * of 'size' bytes. Return the number of bytes the prom accepted. 279 */ 280 int prom_setprop(phandle node, const char *pname, char *value, int size) 281 { 282 unsigned long flags; 283 int ret; 284 285 if (size == 0) 286 return 0; 287 if ((pname == NULL) || (value == NULL)) 288 return 0; 289 spin_lock_irqsave(&prom_lock, flags); 290 ret = prom_nodeops->no_setprop(node, pname, value, size); 291 restore_current(); 292 spin_unlock_irqrestore(&prom_lock, flags); 293 return ret; 294 } 295 EXPORT_SYMBOL(prom_setprop); 296 297 phandle prom_inst2pkg(int inst) 298 { 299 phandle node; 300 unsigned long flags; 301 302 spin_lock_irqsave(&prom_lock, flags); 303 node = (*romvec->pv_v2devops.v2_inst2pkg)(inst); 304 restore_current(); 305 spin_unlock_irqrestore(&prom_lock, flags); 306 if ((s32)node == -1) 307 return 0; 308 return node; 309 } 310