1 /* 2 * Copyright (c) 2011 The Chromium OS Authors. 3 * See file CREDITS for list of people who contributed to this 4 * project. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation; either version 2 of 9 * the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 19 * MA 02111-1307 USA 20 */ 21 22 #include <common.h> 23 #include <serial.h> 24 #include <libfdt.h> 25 #include <fdtdec.h> 26 27 /* we need the generic GPIO interface here */ 28 #include <asm-generic/gpio.h> 29 30 DECLARE_GLOBAL_DATA_PTR; 31 32 /* 33 * Here are the type we know about. One day we might allow drivers to 34 * register. For now we just put them here. The COMPAT macro allows us to 35 * turn this into a sparse list later, and keeps the ID with the name. 36 */ 37 #define COMPAT(id, name) name 38 static const char * const compat_names[COMPAT_COUNT] = { 39 COMPAT(UNKNOWN, "<none>"), 40 COMPAT(NVIDIA_TEGRA20_USB, "nvidia,tegra20-ehci"), 41 COMPAT(NVIDIA_TEGRA20_I2C, "nvidia,tegra20-i2c"), 42 COMPAT(NVIDIA_TEGRA20_DVC, "nvidia,tegra20-i2c-dvc"), 43 }; 44 45 const char *fdtdec_get_compatible(enum fdt_compat_id id) 46 { 47 /* We allow reading of the 'unknown' ID for testing purposes */ 48 assert(id >= 0 && id < COMPAT_COUNT); 49 return compat_names[id]; 50 } 51 52 /** 53 * Look in the FDT for an alias with the given name and return its node. 54 * 55 * @param blob FDT blob 56 * @param name alias name to look up 57 * @return node offset if found, or an error code < 0 otherwise 58 */ 59 static int find_alias_node(const void *blob, const char *name) 60 { 61 const char *path; 62 int alias_node; 63 64 debug("find_alias_node: %s\n", name); 65 alias_node = fdt_path_offset(blob, "/aliases"); 66 if (alias_node < 0) 67 return alias_node; 68 path = fdt_getprop(blob, alias_node, name, NULL); 69 if (!path) 70 return -FDT_ERR_NOTFOUND; 71 return fdt_path_offset(blob, path); 72 } 73 74 fdt_addr_t fdtdec_get_addr(const void *blob, int node, 75 const char *prop_name) 76 { 77 const fdt_addr_t *cell; 78 int len; 79 80 debug("get_addr: %s\n", prop_name); 81 cell = fdt_getprop(blob, node, prop_name, &len); 82 if (cell && (len == sizeof(fdt_addr_t) || 83 len == sizeof(fdt_addr_t) * 2)) 84 return fdt_addr_to_cpu(*cell); 85 return FDT_ADDR_T_NONE; 86 } 87 88 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, 89 s32 default_val) 90 { 91 const s32 *cell; 92 int len; 93 94 debug("get_size: %s\n", prop_name); 95 cell = fdt_getprop(blob, node, prop_name, &len); 96 if (cell && len >= sizeof(s32)) 97 return fdt32_to_cpu(cell[0]); 98 return default_val; 99 } 100 101 int fdtdec_get_is_enabled(const void *blob, int node) 102 { 103 const char *cell; 104 105 /* 106 * It should say "okay", so only allow that. Some fdts use "ok" but 107 * this is a bug. Please fix your device tree source file. See here 108 * for discussion: 109 * 110 * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html 111 */ 112 cell = fdt_getprop(blob, node, "status", NULL); 113 if (cell) 114 return 0 == strcmp(cell, "okay"); 115 return 1; 116 } 117 118 enum fdt_compat_id fd_dec_lookup(const void *blob, int node) 119 { 120 enum fdt_compat_id id; 121 122 /* Search our drivers */ 123 for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++) 124 if (0 == fdt_node_check_compatible(blob, node, 125 compat_names[id])) 126 return id; 127 return COMPAT_UNKNOWN; 128 } 129 130 int fdtdec_next_compatible(const void *blob, int node, 131 enum fdt_compat_id id) 132 { 133 return fdt_node_offset_by_compatible(blob, node, compat_names[id]); 134 } 135 136 int fdtdec_next_alias(const void *blob, const char *name, 137 enum fdt_compat_id id, int *upto) 138 { 139 #define MAX_STR_LEN 20 140 char str[MAX_STR_LEN + 20]; 141 int node, err; 142 143 /* snprintf() is not available */ 144 assert(strlen(name) < MAX_STR_LEN); 145 sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto); 146 node = find_alias_node(blob, str); 147 if (node < 0) 148 return node; 149 err = fdt_node_check_compatible(blob, node, compat_names[id]); 150 if (err < 0) 151 return err; 152 if (err) 153 return -FDT_ERR_NOTFOUND; 154 (*upto)++; 155 return node; 156 } 157 158 int fdtdec_find_aliases_for_id(const void *blob, const char *name, 159 enum fdt_compat_id id, int *node_list, int maxcount) 160 { 161 memset(node_list, '\0', sizeof(*node_list) * maxcount); 162 163 return fdtdec_add_aliases_for_id(blob, name, id, node_list, maxcount); 164 } 165 166 /* TODO: Can we tighten this code up a little? */ 167 int fdtdec_add_aliases_for_id(const void *blob, const char *name, 168 enum fdt_compat_id id, int *node_list, int maxcount) 169 { 170 int name_len = strlen(name); 171 int nodes[maxcount]; 172 int num_found = 0; 173 int offset, node; 174 int alias_node; 175 int count; 176 int i, j; 177 178 /* find the alias node if present */ 179 alias_node = fdt_path_offset(blob, "/aliases"); 180 181 /* 182 * start with nothing, and we can assume that the root node can't 183 * match 184 */ 185 memset(nodes, '\0', sizeof(nodes)); 186 187 /* First find all the compatible nodes */ 188 for (node = count = 0; node >= 0 && count < maxcount;) { 189 node = fdtdec_next_compatible(blob, node, id); 190 if (node >= 0) 191 nodes[count++] = node; 192 } 193 if (node >= 0) 194 debug("%s: warning: maxcount exceeded with alias '%s'\n", 195 __func__, name); 196 197 /* Now find all the aliases */ 198 for (offset = fdt_first_property_offset(blob, alias_node); 199 offset > 0; 200 offset = fdt_next_property_offset(blob, offset)) { 201 const struct fdt_property *prop; 202 const char *path; 203 int number; 204 int found; 205 206 node = 0; 207 prop = fdt_get_property_by_offset(blob, offset, NULL); 208 path = fdt_string(blob, fdt32_to_cpu(prop->nameoff)); 209 if (prop->len && 0 == strncmp(path, name, name_len)) 210 node = fdt_path_offset(blob, prop->data); 211 if (node <= 0) 212 continue; 213 214 /* Get the alias number */ 215 number = simple_strtoul(path + name_len, NULL, 10); 216 if (number < 0 || number >= maxcount) { 217 debug("%s: warning: alias '%s' is out of range\n", 218 __func__, path); 219 continue; 220 } 221 222 /* Make sure the node we found is actually in our list! */ 223 found = -1; 224 for (j = 0; j < count; j++) 225 if (nodes[j] == node) { 226 found = j; 227 break; 228 } 229 230 if (found == -1) { 231 debug("%s: warning: alias '%s' points to a node " 232 "'%s' that is missing or is not compatible " 233 " with '%s'\n", __func__, path, 234 fdt_get_name(blob, node, NULL), 235 compat_names[id]); 236 continue; 237 } 238 239 /* 240 * Add this node to our list in the right place, and mark 241 * it as done. 242 */ 243 if (fdtdec_get_is_enabled(blob, node)) { 244 if (node_list[number]) { 245 debug("%s: warning: alias '%s' requires that " 246 "a node be placed in the list in a " 247 "position which is already filled by " 248 "node '%s'\n", __func__, path, 249 fdt_get_name(blob, node, NULL)); 250 continue; 251 } 252 node_list[number] = node; 253 if (number >= num_found) 254 num_found = number + 1; 255 } 256 nodes[found] = 0; 257 } 258 259 /* Add any nodes not mentioned by an alias */ 260 for (i = j = 0; i < maxcount; i++) { 261 if (!node_list[i]) { 262 for (; j < maxcount; j++) 263 if (nodes[j] && 264 fdtdec_get_is_enabled(blob, nodes[j])) 265 break; 266 267 /* Have we run out of nodes to add? */ 268 if (j == maxcount) 269 break; 270 271 assert(!node_list[i]); 272 node_list[i] = nodes[j++]; 273 if (i >= num_found) 274 num_found = i + 1; 275 } 276 } 277 278 return num_found; 279 } 280 281 int fdtdec_check_fdt(void) 282 { 283 /* 284 * We must have an FDT, but we cannot panic() yet since the console 285 * is not ready. So for now, just assert(). Boards which need an early 286 * FDT (prior to console ready) will need to make their own 287 * arrangements and do their own checks. 288 */ 289 assert(!fdtdec_prepare_fdt()); 290 return 0; 291 } 292 293 /* 294 * This function is a little odd in that it accesses global data. At some 295 * point if the architecture board.c files merge this will make more sense. 296 * Even now, it is common code. 297 */ 298 int fdtdec_prepare_fdt(void) 299 { 300 if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob)) { 301 printf("No valid FDT found - please append one to U-Boot " 302 "binary, use u-boot-dtb.bin or define " 303 "CONFIG_OF_EMBED\n"); 304 return -1; 305 } 306 return 0; 307 } 308 309 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name) 310 { 311 const u32 *phandle; 312 int lookup; 313 314 phandle = fdt_getprop(blob, node, prop_name, NULL); 315 if (!phandle) 316 return -FDT_ERR_NOTFOUND; 317 318 lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle)); 319 return lookup; 320 } 321 322 /** 323 * Look up a property in a node and check that it has a minimum length. 324 * 325 * @param blob FDT blob 326 * @param node node to examine 327 * @param prop_name name of property to find 328 * @param min_len minimum property length in bytes 329 * @param err 0 if ok, or -FDT_ERR_NOTFOUND if the property is not 330 found, or -FDT_ERR_BADLAYOUT if not enough data 331 * @return pointer to cell, which is only valid if err == 0 332 */ 333 static const void *get_prop_check_min_len(const void *blob, int node, 334 const char *prop_name, int min_len, int *err) 335 { 336 const void *cell; 337 int len; 338 339 debug("%s: %s\n", __func__, prop_name); 340 cell = fdt_getprop(blob, node, prop_name, &len); 341 if (!cell) 342 *err = -FDT_ERR_NOTFOUND; 343 else if (len < min_len) 344 *err = -FDT_ERR_BADLAYOUT; 345 else 346 *err = 0; 347 return cell; 348 } 349 350 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, 351 u32 *array, int count) 352 { 353 const u32 *cell; 354 int i, err = 0; 355 356 debug("%s: %s\n", __func__, prop_name); 357 cell = get_prop_check_min_len(blob, node, prop_name, 358 sizeof(u32) * count, &err); 359 if (!err) { 360 for (i = 0; i < count; i++) 361 array[i] = fdt32_to_cpu(cell[i]); 362 } 363 return err; 364 } 365 366 int fdtdec_get_bool(const void *blob, int node, const char *prop_name) 367 { 368 const s32 *cell; 369 int len; 370 371 debug("%s: %s\n", __func__, prop_name); 372 cell = fdt_getprop(blob, node, prop_name, &len); 373 return cell != NULL; 374 } 375 376 /** 377 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no 378 * terminating item. 379 * 380 * @param blob FDT blob to use 381 * @param node Node to look at 382 * @param prop_name Node property name 383 * @param gpio Array of gpio elements to fill from FDT. This will be 384 * untouched if either 0 or an error is returned 385 * @param max_count Maximum number of elements allowed 386 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would 387 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing. 388 */ 389 static int fdtdec_decode_gpios(const void *blob, int node, 390 const char *prop_name, struct fdt_gpio_state *gpio, 391 int max_count) 392 { 393 const struct fdt_property *prop; 394 const u32 *cell; 395 const char *name; 396 int len, i; 397 398 debug("%s: %s\n", __func__, prop_name); 399 assert(max_count > 0); 400 prop = fdt_get_property(blob, node, prop_name, &len); 401 if (!prop) { 402 debug("FDT: %s: property '%s' missing\n", __func__, prop_name); 403 return -FDT_ERR_NOTFOUND; 404 } 405 406 /* We will use the name to tag the GPIO */ 407 name = fdt_string(blob, fdt32_to_cpu(prop->nameoff)); 408 cell = (u32 *)prop->data; 409 len /= sizeof(u32) * 3; /* 3 cells per GPIO record */ 410 if (len > max_count) { 411 debug("FDT: %s: too many GPIOs / cells for " 412 "property '%s'\n", __func__, prop_name); 413 return -FDT_ERR_BADLAYOUT; 414 } 415 416 /* Read out the GPIO data from the cells */ 417 for (i = 0; i < len; i++, cell += 3) { 418 gpio[i].gpio = fdt32_to_cpu(cell[1]); 419 gpio[i].flags = fdt32_to_cpu(cell[2]); 420 gpio[i].name = name; 421 } 422 423 return len; 424 } 425 426 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, 427 struct fdt_gpio_state *gpio) 428 { 429 int err; 430 431 debug("%s: %s\n", __func__, prop_name); 432 gpio->gpio = FDT_GPIO_NONE; 433 gpio->name = NULL; 434 err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1); 435 return err == 1 ? 0 : err; 436 } 437 438 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio) 439 { 440 /* 441 * Return success if there is no GPIO defined. This is used for 442 * optional GPIOs) 443 */ 444 if (!fdt_gpio_isvalid(gpio)) 445 return 0; 446 447 if (gpio_request(gpio->gpio, gpio->name)) 448 return -1; 449 return 0; 450 } 451