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[8]; 99 const __be32 *match_array = initial_match_array; 100 const __be32 *tmp, *imap, *imask, dummy_imask[] = { ~0, ~0, ~0, ~0, ~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 /* Precalculate the match array - this simplifies match loop */ 151 for (i = 0; i < addrsize; i++) 152 initial_match_array[i] = addr ? addr[i] : 0; 153 for (i = 0; i < intsize; i++) 154 initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]); 155 156 /* Now start the actual "proper" walk of the interrupt tree */ 157 while (ipar != NULL) { 158 /* Now check if cursor is an interrupt-controller and if it is 159 * then we are done 160 */ 161 if (of_get_property(ipar, "interrupt-controller", NULL) != 162 NULL) { 163 pr_debug(" -> got it !\n"); 164 of_node_put(old); 165 return 0; 166 } 167 168 /* 169 * interrupt-map parsing does not work without a reg 170 * property when #address-cells != 0 171 */ 172 if (addrsize && !addr) { 173 pr_debug(" -> no reg passed in when needed !\n"); 174 goto fail; 175 } 176 177 /* Now look for an interrupt-map */ 178 imap = of_get_property(ipar, "interrupt-map", &imaplen); 179 /* No interrupt map, check for an interrupt parent */ 180 if (imap == NULL) { 181 pr_debug(" -> no map, getting parent\n"); 182 newpar = of_irq_find_parent(ipar); 183 goto skiplevel; 184 } 185 imaplen /= sizeof(u32); 186 187 /* Look for a mask */ 188 imask = of_get_property(ipar, "interrupt-map-mask", NULL); 189 if (!imask) 190 imask = dummy_imask; 191 192 /* Parse interrupt-map */ 193 match = 0; 194 while (imaplen > (addrsize + intsize + 1) && !match) { 195 /* Compare specifiers */ 196 match = 1; 197 for (i = 0; i < (addrsize + intsize); i++, imaplen--) 198 match = !((match_array[i] ^ *imap++) & imask[i]); 199 200 pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen); 201 202 /* Get the interrupt parent */ 203 if (of_irq_workarounds & OF_IMAP_NO_PHANDLE) 204 newpar = of_node_get(of_irq_dflt_pic); 205 else 206 newpar = of_find_node_by_phandle(be32_to_cpup(imap)); 207 imap++; 208 --imaplen; 209 210 /* Check if not found */ 211 if (newpar == NULL) { 212 pr_debug(" -> imap parent not found !\n"); 213 goto fail; 214 } 215 216 /* Get #interrupt-cells and #address-cells of new 217 * parent 218 */ 219 tmp = of_get_property(newpar, "#interrupt-cells", NULL); 220 if (tmp == NULL) { 221 pr_debug(" -> parent lacks #interrupt-cells!\n"); 222 goto fail; 223 } 224 newintsize = be32_to_cpu(*tmp); 225 tmp = of_get_property(newpar, "#address-cells", NULL); 226 newaddrsize = (tmp == NULL) ? 0 : be32_to_cpu(*tmp); 227 228 pr_debug(" -> newintsize=%d, newaddrsize=%d\n", 229 newintsize, newaddrsize); 230 231 /* Check for malformed properties */ 232 if (imaplen < (newaddrsize + newintsize)) 233 goto fail; 234 235 imap += newaddrsize + newintsize; 236 imaplen -= newaddrsize + newintsize; 237 238 pr_debug(" -> imaplen=%d\n", imaplen); 239 } 240 if (!match) 241 goto fail; 242 243 /* 244 * Successfully parsed an interrrupt-map translation; copy new 245 * interrupt specifier into the out_irq structure 246 */ 247 of_node_put(out_irq->np); 248 out_irq->np = of_node_get(newpar); 249 250 match_array = imap - newaddrsize - newintsize; 251 for (i = 0; i < newintsize; i++) 252 out_irq->args[i] = be32_to_cpup(imap - newintsize + i); 253 out_irq->args_count = intsize = newintsize; 254 addrsize = newaddrsize; 255 256 skiplevel: 257 /* Iterate again with new parent */ 258 pr_debug(" -> new parent: %s\n", of_node_full_name(newpar)); 259 of_node_put(ipar); 260 ipar = newpar; 261 newpar = NULL; 262 } 263 fail: 264 of_node_put(ipar); 265 of_node_put(out_irq->np); 266 of_node_put(newpar); 267 268 return -EINVAL; 269 } 270 EXPORT_SYMBOL_GPL(of_irq_parse_raw); 271 272 /** 273 * of_irq_parse_one - Resolve an interrupt for a device 274 * @device: the device whose interrupt is to be resolved 275 * @index: index of the interrupt to resolve 276 * @out_irq: structure of_irq filled by this function 277 * 278 * This function resolves an interrupt for a node by walking the interrupt tree, 279 * finding which interrupt controller node it is attached to, and returning the 280 * interrupt specifier that can be used to retrieve a Linux IRQ number. 281 */ 282 int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq) 283 { 284 struct device_node *p; 285 const __be32 *intspec, *tmp, *addr; 286 u32 intsize, intlen; 287 int i, res = -EINVAL; 288 289 pr_debug("of_irq_parse_one: dev=%s, index=%d\n", of_node_full_name(device), index); 290 291 /* OldWorld mac stuff is "special", handle out of line */ 292 if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC) 293 return of_irq_parse_oldworld(device, index, out_irq); 294 295 /* Get the reg property (if any) */ 296 addr = of_get_property(device, "reg", NULL); 297 298 /* Get the interrupts property */ 299 intspec = of_get_property(device, "interrupts", &intlen); 300 if (intspec == NULL) { 301 /* Try the new-style interrupts-extended */ 302 res = of_parse_phandle_with_args(device, "interrupts-extended", 303 "#interrupt-cells", index, out_irq); 304 if (res) 305 return -EINVAL; 306 return of_irq_parse_raw(addr, out_irq); 307 } 308 intlen /= sizeof(*intspec); 309 310 pr_debug(" intspec=%d intlen=%d\n", be32_to_cpup(intspec), intlen); 311 312 /* Look for the interrupt parent. */ 313 p = of_irq_find_parent(device); 314 if (p == NULL) 315 return -EINVAL; 316 317 /* Get size of interrupt specifier */ 318 tmp = of_get_property(p, "#interrupt-cells", NULL); 319 if (tmp == NULL) 320 goto out; 321 intsize = be32_to_cpu(*tmp); 322 323 pr_debug(" intsize=%d intlen=%d\n", intsize, intlen); 324 325 /* Check index */ 326 if ((index + 1) * intsize > intlen) 327 goto out; 328 329 /* Copy intspec into irq structure */ 330 intspec += index * intsize; 331 out_irq->np = p; 332 out_irq->args_count = intsize; 333 for (i = 0; i < intsize; i++) 334 out_irq->args[i] = be32_to_cpup(intspec++); 335 336 /* Check if there are any interrupt-map translations to process */ 337 res = of_irq_parse_raw(addr, out_irq); 338 out: 339 of_node_put(p); 340 return res; 341 } 342 EXPORT_SYMBOL_GPL(of_irq_parse_one); 343 344 /** 345 * of_irq_to_resource - Decode a node's IRQ and return it as a resource 346 * @dev: pointer to device tree node 347 * @index: zero-based index of the irq 348 * @r: pointer to resource structure to return result into. 349 */ 350 int of_irq_to_resource(struct device_node *dev, int index, struct resource *r) 351 { 352 int irq = irq_of_parse_and_map(dev, index); 353 354 /* Only dereference the resource if both the 355 * resource and the irq are valid. */ 356 if (r && irq) { 357 const char *name = NULL; 358 359 memset(r, 0, sizeof(*r)); 360 /* 361 * Get optional "interrupts-names" property to add a name 362 * to the resource. 363 */ 364 of_property_read_string_index(dev, "interrupt-names", index, 365 &name); 366 367 r->start = r->end = irq; 368 r->flags = IORESOURCE_IRQ | irqd_get_trigger_type(irq_get_irq_data(irq)); 369 r->name = name ? name : of_node_full_name(dev); 370 } 371 372 return irq; 373 } 374 EXPORT_SYMBOL_GPL(of_irq_to_resource); 375 376 /** 377 * of_irq_count - Count the number of IRQs a node uses 378 * @dev: pointer to device tree node 379 */ 380 int of_irq_count(struct device_node *dev) 381 { 382 struct of_phandle_args irq; 383 int nr = 0; 384 385 while (of_irq_parse_one(dev, nr, &irq) == 0) 386 nr++; 387 388 return nr; 389 } 390 391 /** 392 * of_irq_to_resource_table - Fill in resource table with node's IRQ info 393 * @dev: pointer to device tree node 394 * @res: array of resources to fill in 395 * @nr_irqs: the number of IRQs (and upper bound for num of @res elements) 396 * 397 * Returns the size of the filled in table (up to @nr_irqs). 398 */ 399 int of_irq_to_resource_table(struct device_node *dev, struct resource *res, 400 int nr_irqs) 401 { 402 int i; 403 404 for (i = 0; i < nr_irqs; i++, res++) 405 if (!of_irq_to_resource(dev, i, res)) 406 break; 407 408 return i; 409 } 410 EXPORT_SYMBOL_GPL(of_irq_to_resource_table); 411 412 struct intc_desc { 413 struct list_head list; 414 struct device_node *dev; 415 struct device_node *interrupt_parent; 416 }; 417 418 /** 419 * of_irq_init - Scan and init matching interrupt controllers in DT 420 * @matches: 0 terminated array of nodes to match and init function to call 421 * 422 * This function scans the device tree for matching interrupt controller nodes, 423 * and calls their initialization functions in order with parents first. 424 */ 425 void __init of_irq_init(const struct of_device_id *matches) 426 { 427 struct device_node *np, *parent = NULL; 428 struct intc_desc *desc, *temp_desc; 429 struct list_head intc_desc_list, intc_parent_list; 430 431 INIT_LIST_HEAD(&intc_desc_list); 432 INIT_LIST_HEAD(&intc_parent_list); 433 434 for_each_matching_node(np, matches) { 435 if (!of_find_property(np, "interrupt-controller", NULL)) 436 continue; 437 /* 438 * Here, we allocate and populate an intc_desc with the node 439 * pointer, interrupt-parent device_node etc. 440 */ 441 desc = kzalloc(sizeof(*desc), GFP_KERNEL); 442 if (WARN_ON(!desc)) 443 goto err; 444 445 desc->dev = np; 446 desc->interrupt_parent = of_irq_find_parent(np); 447 if (desc->interrupt_parent == np) 448 desc->interrupt_parent = NULL; 449 list_add_tail(&desc->list, &intc_desc_list); 450 } 451 452 /* 453 * The root irq controller is the one without an interrupt-parent. 454 * That one goes first, followed by the controllers that reference it, 455 * followed by the ones that reference the 2nd level controllers, etc. 456 */ 457 while (!list_empty(&intc_desc_list)) { 458 /* 459 * Process all controllers with the current 'parent'. 460 * First pass will be looking for NULL as the parent. 461 * The assumption is that NULL parent means a root controller. 462 */ 463 list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) { 464 const struct of_device_id *match; 465 int ret; 466 of_irq_init_cb_t irq_init_cb; 467 468 if (desc->interrupt_parent != parent) 469 continue; 470 471 list_del(&desc->list); 472 match = of_match_node(matches, desc->dev); 473 if (WARN(!match->data, 474 "of_irq_init: no init function for %s\n", 475 match->compatible)) { 476 kfree(desc); 477 continue; 478 } 479 480 pr_debug("of_irq_init: init %s @ %p, parent %p\n", 481 match->compatible, 482 desc->dev, desc->interrupt_parent); 483 irq_init_cb = (of_irq_init_cb_t)match->data; 484 ret = irq_init_cb(desc->dev, desc->interrupt_parent); 485 if (ret) { 486 kfree(desc); 487 continue; 488 } 489 490 /* 491 * This one is now set up; add it to the parent list so 492 * its children can get processed in a subsequent pass. 493 */ 494 list_add_tail(&desc->list, &intc_parent_list); 495 } 496 497 /* Get the next pending parent that might have children */ 498 desc = list_first_entry_or_null(&intc_parent_list, 499 typeof(*desc), list); 500 if (!desc) { 501 pr_err("of_irq_init: children remain, but no parents\n"); 502 break; 503 } 504 list_del(&desc->list); 505 parent = desc->dev; 506 kfree(desc); 507 } 508 509 list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) { 510 list_del(&desc->list); 511 kfree(desc); 512 } 513 err: 514 list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) { 515 list_del(&desc->list); 516 kfree(desc); 517 } 518 } 519