1 /* 2 * Derived from arch/i386/kernel/irq.c 3 * Copyright (C) 1992 Linus Torvalds 4 * Adapted from arch/i386 by Gary Thomas 5 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 6 * Updated and modified by Cort Dougan <cort@fsmlabs.com> 7 * Copyright (C) 1996-2001 Cort Dougan 8 * Adapted for Power Macintosh by Paul Mackerras 9 * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au) 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * as published by the Free Software Foundation; either version 14 * 2 of the License, or (at your option) any later version. 15 * 16 * This file contains the code used to make IRQ descriptions in the 17 * device tree to actual irq numbers on an interrupt controller 18 * driver. 19 */ 20 21 #include <linux/errno.h> 22 #include <linux/list.h> 23 #include <linux/module.h> 24 #include <linux/of.h> 25 #include <linux/of_irq.h> 26 #include <linux/string.h> 27 #include <linux/slab.h> 28 29 /** 30 * irq_of_parse_and_map - Parse and map an interrupt into linux virq space 31 * @dev: Device node of the device whose interrupt is to be mapped 32 * @index: Index of the interrupt to map 33 * 34 * This function is a wrapper that chains of_irq_parse_one() and 35 * irq_create_of_mapping() to make things easier to callers 36 */ 37 unsigned int irq_of_parse_and_map(struct device_node *dev, int index) 38 { 39 struct of_phandle_args oirq; 40 41 if (of_irq_parse_one(dev, index, &oirq)) 42 return 0; 43 44 return irq_create_of_mapping(&oirq); 45 } 46 EXPORT_SYMBOL_GPL(irq_of_parse_and_map); 47 48 /** 49 * of_irq_find_parent - Given a device node, find its interrupt parent node 50 * @child: pointer to device node 51 * 52 * Returns a pointer to the interrupt parent node, or NULL if the interrupt 53 * parent could not be determined. 54 */ 55 struct device_node *of_irq_find_parent(struct device_node *child) 56 { 57 struct device_node *p; 58 const __be32 *parp; 59 60 if (!of_node_get(child)) 61 return NULL; 62 63 do { 64 parp = of_get_property(child, "interrupt-parent", NULL); 65 if (parp == NULL) 66 p = of_get_parent(child); 67 else { 68 if (of_irq_workarounds & OF_IMAP_NO_PHANDLE) 69 p = of_node_get(of_irq_dflt_pic); 70 else 71 p = of_find_node_by_phandle(be32_to_cpup(parp)); 72 } 73 of_node_put(child); 74 child = p; 75 } while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL); 76 77 return p; 78 } 79 80 /** 81 * of_irq_parse_raw - Low level interrupt tree parsing 82 * @parent: the device interrupt parent 83 * @addr: address specifier (start of "reg" property of the device) in be32 format 84 * @out_irq: structure of_irq updated by this function 85 * 86 * Returns 0 on success and a negative number on error 87 * 88 * This function is a low-level interrupt tree walking function. It 89 * can be used to do a partial walk with synthetized reg and interrupts 90 * properties, for example when resolving PCI interrupts when no device 91 * node exist for the parent. It takes an interrupt specifier structure as 92 * input, walks the tree looking for any interrupt-map properties, translates 93 * the specifier for each map, and then returns the translated map. 94 */ 95 int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq) 96 { 97 struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL; 98 __be32 initial_match_array[MAX_PHANDLE_ARGS]; 99 const __be32 *match_array = initial_match_array; 100 const __be32 *tmp, *imap, *imask, dummy_imask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 }; 101 u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0; 102 int imaplen, match, i; 103 104 #ifdef DEBUG 105 of_print_phandle_args("of_irq_parse_raw: ", out_irq); 106 #endif 107 108 ipar = of_node_get(out_irq->np); 109 110 /* First get the #interrupt-cells property of the current cursor 111 * that tells us how to interpret the passed-in intspec. If there 112 * is none, we are nice and just walk up the tree 113 */ 114 do { 115 tmp = of_get_property(ipar, "#interrupt-cells", NULL); 116 if (tmp != NULL) { 117 intsize = be32_to_cpu(*tmp); 118 break; 119 } 120 tnode = ipar; 121 ipar = of_irq_find_parent(ipar); 122 of_node_put(tnode); 123 } while (ipar); 124 if (ipar == NULL) { 125 pr_debug(" -> no parent found !\n"); 126 goto fail; 127 } 128 129 pr_debug("of_irq_parse_raw: ipar=%s, size=%d\n", of_node_full_name(ipar), intsize); 130 131 if (out_irq->args_count != intsize) 132 return -EINVAL; 133 134 /* Look for this #address-cells. We have to implement the old linux 135 * trick of looking for the parent here as some device-trees rely on it 136 */ 137 old = of_node_get(ipar); 138 do { 139 tmp = of_get_property(old, "#address-cells", NULL); 140 tnode = of_get_parent(old); 141 of_node_put(old); 142 old = tnode; 143 } while (old && tmp == NULL); 144 of_node_put(old); 145 old = NULL; 146 addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp); 147 148 pr_debug(" -> addrsize=%d\n", addrsize); 149 150 /* Range check so that the temporary buffer doesn't overflow */ 151 if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)) 152 goto fail; 153 154 /* Precalculate the match array - this simplifies match loop */ 155 for (i = 0; i < addrsize; i++) 156 initial_match_array[i] = addr ? addr[i] : 0; 157 for (i = 0; i < intsize; i++) 158 initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]); 159 160 /* Now start the actual "proper" walk of the interrupt tree */ 161 while (ipar != NULL) { 162 /* Now check if cursor is an interrupt-controller and if it is 163 * then we are done 164 */ 165 if (of_get_property(ipar, "interrupt-controller", NULL) != 166 NULL) { 167 pr_debug(" -> got it !\n"); 168 of_node_put(old); 169 return 0; 170 } 171 172 /* 173 * interrupt-map parsing does not work without a reg 174 * property when #address-cells != 0 175 */ 176 if (addrsize && !addr) { 177 pr_debug(" -> no reg passed in when needed !\n"); 178 goto fail; 179 } 180 181 /* Now look for an interrupt-map */ 182 imap = of_get_property(ipar, "interrupt-map", &imaplen); 183 /* No interrupt map, check for an interrupt parent */ 184 if (imap == NULL) { 185 pr_debug(" -> no map, getting parent\n"); 186 newpar = of_irq_find_parent(ipar); 187 goto skiplevel; 188 } 189 imaplen /= sizeof(u32); 190 191 /* Look for a mask */ 192 imask = of_get_property(ipar, "interrupt-map-mask", NULL); 193 if (!imask) 194 imask = dummy_imask; 195 196 /* Parse interrupt-map */ 197 match = 0; 198 while (imaplen > (addrsize + intsize + 1) && !match) { 199 /* Compare specifiers */ 200 match = 1; 201 for (i = 0; i < (addrsize + intsize); i++, imaplen--) 202 match &= !((match_array[i] ^ *imap++) & imask[i]); 203 204 pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen); 205 206 /* Get the interrupt parent */ 207 if (of_irq_workarounds & OF_IMAP_NO_PHANDLE) 208 newpar = of_node_get(of_irq_dflt_pic); 209 else 210 newpar = of_find_node_by_phandle(be32_to_cpup(imap)); 211 imap++; 212 --imaplen; 213 214 /* Check if not found */ 215 if (newpar == NULL) { 216 pr_debug(" -> imap parent not found !\n"); 217 goto fail; 218 } 219 220 /* Get #interrupt-cells and #address-cells of new 221 * parent 222 */ 223 tmp = of_get_property(newpar, "#interrupt-cells", NULL); 224 if (tmp == NULL) { 225 pr_debug(" -> parent lacks #interrupt-cells!\n"); 226 goto fail; 227 } 228 newintsize = be32_to_cpu(*tmp); 229 tmp = of_get_property(newpar, "#address-cells", NULL); 230 newaddrsize = (tmp == NULL) ? 0 : be32_to_cpu(*tmp); 231 232 pr_debug(" -> newintsize=%d, newaddrsize=%d\n", 233 newintsize, newaddrsize); 234 235 /* Check for malformed properties */ 236 if (WARN_ON(newaddrsize + newintsize > MAX_PHANDLE_ARGS)) 237 goto fail; 238 if (imaplen < (newaddrsize + newintsize)) 239 goto fail; 240 241 imap += newaddrsize + newintsize; 242 imaplen -= newaddrsize + newintsize; 243 244 pr_debug(" -> imaplen=%d\n", imaplen); 245 } 246 if (!match) 247 goto fail; 248 249 /* 250 * Successfully parsed an interrrupt-map translation; copy new 251 * interrupt specifier into the out_irq structure 252 */ 253 of_node_put(out_irq->np); 254 out_irq->np = of_node_get(newpar); 255 256 match_array = imap - newaddrsize - newintsize; 257 for (i = 0; i < newintsize; i++) 258 out_irq->args[i] = be32_to_cpup(imap - newintsize + i); 259 out_irq->args_count = intsize = newintsize; 260 addrsize = newaddrsize; 261 262 skiplevel: 263 /* Iterate again with new parent */ 264 pr_debug(" -> new parent: %s\n", of_node_full_name(newpar)); 265 of_node_put(ipar); 266 ipar = newpar; 267 newpar = NULL; 268 } 269 fail: 270 of_node_put(ipar); 271 of_node_put(out_irq->np); 272 of_node_put(newpar); 273 274 return -EINVAL; 275 } 276 EXPORT_SYMBOL_GPL(of_irq_parse_raw); 277 278 /** 279 * of_irq_parse_one - Resolve an interrupt for a device 280 * @device: the device whose interrupt is to be resolved 281 * @index: index of the interrupt to resolve 282 * @out_irq: structure of_irq filled by this function 283 * 284 * This function resolves an interrupt for a node by walking the interrupt tree, 285 * finding which interrupt controller node it is attached to, and returning the 286 * interrupt specifier that can be used to retrieve a Linux IRQ number. 287 */ 288 int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq) 289 { 290 struct device_node *p; 291 const __be32 *intspec, *tmp, *addr; 292 u32 intsize, intlen; 293 int i, res = -EINVAL; 294 295 pr_debug("of_irq_parse_one: dev=%s, index=%d\n", of_node_full_name(device), index); 296 297 /* OldWorld mac stuff is "special", handle out of line */ 298 if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC) 299 return of_irq_parse_oldworld(device, index, out_irq); 300 301 /* Get the reg property (if any) */ 302 addr = of_get_property(device, "reg", NULL); 303 304 /* Get the interrupts property */ 305 intspec = of_get_property(device, "interrupts", &intlen); 306 if (intspec == NULL) { 307 /* Try the new-style interrupts-extended */ 308 res = of_parse_phandle_with_args(device, "interrupts-extended", 309 "#interrupt-cells", index, out_irq); 310 if (res) 311 return -EINVAL; 312 return of_irq_parse_raw(addr, out_irq); 313 } 314 intlen /= sizeof(*intspec); 315 316 pr_debug(" intspec=%d intlen=%d\n", be32_to_cpup(intspec), intlen); 317 318 /* Look for the interrupt parent. */ 319 p = of_irq_find_parent(device); 320 if (p == NULL) 321 return -EINVAL; 322 323 /* Get size of interrupt specifier */ 324 tmp = of_get_property(p, "#interrupt-cells", NULL); 325 if (tmp == NULL) 326 goto out; 327 intsize = be32_to_cpu(*tmp); 328 329 pr_debug(" intsize=%d intlen=%d\n", intsize, intlen); 330 331 /* Check index */ 332 if ((index + 1) * intsize > intlen) 333 goto out; 334 335 /* Copy intspec into irq structure */ 336 intspec += index * intsize; 337 out_irq->np = p; 338 out_irq->args_count = intsize; 339 for (i = 0; i < intsize; i++) 340 out_irq->args[i] = be32_to_cpup(intspec++); 341 342 /* Check if there are any interrupt-map translations to process */ 343 res = of_irq_parse_raw(addr, out_irq); 344 out: 345 of_node_put(p); 346 return res; 347 } 348 EXPORT_SYMBOL_GPL(of_irq_parse_one); 349 350 /** 351 * of_irq_to_resource - Decode a node's IRQ and return it as a resource 352 * @dev: pointer to device tree node 353 * @index: zero-based index of the irq 354 * @r: pointer to resource structure to return result into. 355 */ 356 int of_irq_to_resource(struct device_node *dev, int index, struct resource *r) 357 { 358 int irq = irq_of_parse_and_map(dev, index); 359 360 /* Only dereference the resource if both the 361 * resource and the irq are valid. */ 362 if (r && irq) { 363 const char *name = NULL; 364 365 memset(r, 0, sizeof(*r)); 366 /* 367 * Get optional "interrupts-names" property to add a name 368 * to the resource. 369 */ 370 of_property_read_string_index(dev, "interrupt-names", index, 371 &name); 372 373 r->start = r->end = irq; 374 r->flags = IORESOURCE_IRQ | irqd_get_trigger_type(irq_get_irq_data(irq)); 375 r->name = name ? name : of_node_full_name(dev); 376 } 377 378 return irq; 379 } 380 EXPORT_SYMBOL_GPL(of_irq_to_resource); 381 382 /** 383 * of_irq_count - Count the number of IRQs a node uses 384 * @dev: pointer to device tree node 385 */ 386 int of_irq_count(struct device_node *dev) 387 { 388 struct of_phandle_args irq; 389 int nr = 0; 390 391 while (of_irq_parse_one(dev, nr, &irq) == 0) 392 nr++; 393 394 return nr; 395 } 396 397 /** 398 * of_irq_to_resource_table - Fill in resource table with node's IRQ info 399 * @dev: pointer to device tree node 400 * @res: array of resources to fill in 401 * @nr_irqs: the number of IRQs (and upper bound for num of @res elements) 402 * 403 * Returns the size of the filled in table (up to @nr_irqs). 404 */ 405 int of_irq_to_resource_table(struct device_node *dev, struct resource *res, 406 int nr_irqs) 407 { 408 int i; 409 410 for (i = 0; i < nr_irqs; i++, res++) 411 if (!of_irq_to_resource(dev, i, res)) 412 break; 413 414 return i; 415 } 416 EXPORT_SYMBOL_GPL(of_irq_to_resource_table); 417 418 struct intc_desc { 419 struct list_head list; 420 struct device_node *dev; 421 struct device_node *interrupt_parent; 422 }; 423 424 /** 425 * of_irq_init - Scan and init matching interrupt controllers in DT 426 * @matches: 0 terminated array of nodes to match and init function to call 427 * 428 * This function scans the device tree for matching interrupt controller nodes, 429 * and calls their initialization functions in order with parents first. 430 */ 431 void __init of_irq_init(const struct of_device_id *matches) 432 { 433 struct device_node *np, *parent = NULL; 434 struct intc_desc *desc, *temp_desc; 435 struct list_head intc_desc_list, intc_parent_list; 436 437 INIT_LIST_HEAD(&intc_desc_list); 438 INIT_LIST_HEAD(&intc_parent_list); 439 440 for_each_matching_node(np, matches) { 441 if (!of_find_property(np, "interrupt-controller", NULL)) 442 continue; 443 /* 444 * Here, we allocate and populate an intc_desc with the node 445 * pointer, interrupt-parent device_node etc. 446 */ 447 desc = kzalloc(sizeof(*desc), GFP_KERNEL); 448 if (WARN_ON(!desc)) 449 goto err; 450 451 desc->dev = np; 452 desc->interrupt_parent = of_irq_find_parent(np); 453 if (desc->interrupt_parent == np) 454 desc->interrupt_parent = NULL; 455 list_add_tail(&desc->list, &intc_desc_list); 456 } 457 458 /* 459 * The root irq controller is the one without an interrupt-parent. 460 * That one goes first, followed by the controllers that reference it, 461 * followed by the ones that reference the 2nd level controllers, etc. 462 */ 463 while (!list_empty(&intc_desc_list)) { 464 /* 465 * Process all controllers with the current 'parent'. 466 * First pass will be looking for NULL as the parent. 467 * The assumption is that NULL parent means a root controller. 468 */ 469 list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) { 470 const struct of_device_id *match; 471 int ret; 472 of_irq_init_cb_t irq_init_cb; 473 474 if (desc->interrupt_parent != parent) 475 continue; 476 477 list_del(&desc->list); 478 match = of_match_node(matches, desc->dev); 479 if (WARN(!match->data, 480 "of_irq_init: no init function for %s\n", 481 match->compatible)) { 482 kfree(desc); 483 continue; 484 } 485 486 pr_debug("of_irq_init: init %s @ %p, parent %p\n", 487 match->compatible, 488 desc->dev, desc->interrupt_parent); 489 irq_init_cb = (of_irq_init_cb_t)match->data; 490 ret = irq_init_cb(desc->dev, desc->interrupt_parent); 491 if (ret) { 492 kfree(desc); 493 continue; 494 } 495 496 /* 497 * This one is now set up; add it to the parent list so 498 * its children can get processed in a subsequent pass. 499 */ 500 list_add_tail(&desc->list, &intc_parent_list); 501 } 502 503 /* Get the next pending parent that might have children */ 504 desc = list_first_entry_or_null(&intc_parent_list, 505 typeof(*desc), list); 506 if (!desc) { 507 pr_err("of_irq_init: children remain, but no parents\n"); 508 break; 509 } 510 list_del(&desc->list); 511 parent = desc->dev; 512 kfree(desc); 513 } 514 515 list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) { 516 list_del(&desc->list); 517 kfree(desc); 518 } 519 err: 520 list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) { 521 list_del(&desc->list); 522 kfree(desc); 523 } 524 } 525