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power: reset: corrections for simple syscon reboot driver
[linux-2.6/btrfs-unstable.git] / drivers / of / address.c
blobe3718250d66e4f2b5fcb13c9936b7e28615440ec
1
2 #include <linux/device.h>
3 #include <linux/io.h>
4 #include <linux/ioport.h>
5 #include <linux/module.h>
6 #include <linux/of_address.h>
7 #include <linux/pci_regs.h>
8 #include <linux/string.h>
9
10 /* Max address size we deal with */
11 #define OF_MAX_ADDR_CELLS 4
12 #define OF_CHECK_ADDR_COUNT(na) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS)
13 #define OF_CHECK_COUNTS(na, ns) (OF_CHECK_ADDR_COUNT(na) && (ns) > 0)
14
15 static struct of_bus *of_match_bus(struct device_node *np);
16 static int __of_address_to_resource(struct device_node *dev,
17 const __be32 *addrp, u64 size, unsigned int flags,
18 const char *name, struct resource *r);
19
20 /* Debug utility */
21 #ifdef DEBUG
22 static void of_dump_addr(const char *s, const __be32 *addr, int na)
23 {
24 printk(KERN_DEBUG "%s", s);
25 while (na--)
26 printk(" %08x", be32_to_cpu(*(addr++)));
27 printk("\n");
28 }
29 #else
30 static void of_dump_addr(const char *s, const __be32 *addr, int na) { }
31 #endif
32
33 /* Callbacks for bus specific translators */
34 struct of_bus {
35 const char *name;
36 const char *addresses;
37 int (*match)(struct device_node *parent);
38 void (*count_cells)(struct device_node *child,
39 int *addrc, int *sizec);
40 u64 (*map)(__be32 *addr, const __be32 *range,
41 int na, int ns, int pna);
42 int (*translate)(__be32 *addr, u64 offset, int na);
43 unsigned int (*get_flags)(const __be32 *addr);
44 };
45
46 /*
47 * Default translator (generic bus)
48 */
49
50 static void of_bus_default_count_cells(struct device_node *dev,
51 int *addrc, int *sizec)
52 {
53 if (addrc)
54 *addrc = of_n_addr_cells(dev);
55 if (sizec)
56 *sizec = of_n_size_cells(dev);
57 }
58
59 static u64 of_bus_default_map(__be32 *addr, const __be32 *range,
60 int na, int ns, int pna)
61 {
62 u64 cp, s, da;
63
64 cp = of_read_number(range, na);
65 s = of_read_number(range + na + pna, ns);
66 da = of_read_number(addr, na);
67
68 pr_debug("OF: default map, cp=%llx, s=%llx, da=%llx\n",
69 (unsigned long long)cp, (unsigned long long)s,
70 (unsigned long long)da);
71
72 if (da < cp || da >= (cp + s))
73 return OF_BAD_ADDR;
74 return da - cp;
75 }
76
77 static int of_bus_default_translate(__be32 *addr, u64 offset, int na)
78 {
79 u64 a = of_read_number(addr, na);
80 memset(addr, 0, na * 4);
81 a += offset;
82 if (na > 1)
83 addr[na - 2] = cpu_to_be32(a >> 32);
84 addr[na - 1] = cpu_to_be32(a & 0xffffffffu);
85
86 return 0;
87 }
88
89 static unsigned int of_bus_default_get_flags(const __be32 *addr)
90 {
91 return IORESOURCE_MEM;
92 }
93
94 #ifdef CONFIG_OF_ADDRESS_PCI
95 /*
96 * PCI bus specific translator
97 */
98
99 static int of_bus_pci_match(struct device_node *np)
100 {
101 /*
102 * "pciex" is PCI Express
103 * "vci" is for the /chaos bridge on 1st-gen PCI powermacs
104 * "ht" is hypertransport
105 */
106 return !strcmp(np->type, "pci") || !strcmp(np->type, "pciex") ||
107 !strcmp(np->type, "vci") || !strcmp(np->type, "ht");
108 }
109
110 static void of_bus_pci_count_cells(struct device_node *np,
111 int *addrc, int *sizec)
112 {
113 if (addrc)
114 *addrc = 3;
115 if (sizec)
116 *sizec = 2;
117 }
118
119 static unsigned int of_bus_pci_get_flags(const __be32 *addr)
120 {
121 unsigned int flags = 0;
122 u32 w = be32_to_cpup(addr);
123
124 switch((w >> 24) & 0x03) {
125 case 0x01:
126 flags |= IORESOURCE_IO;
127 break;
128 case 0x02: /* 32 bits */
129 case 0x03: /* 64 bits */
130 flags |= IORESOURCE_MEM;
131 break;
132 }
133 if (w & 0x40000000)
134 flags |= IORESOURCE_PREFETCH;
135 return flags;
136 }
137
138 static u64 of_bus_pci_map(__be32 *addr, const __be32 *range, int na, int ns,
139 int pna)
140 {
141 u64 cp, s, da;
142 unsigned int af, rf;
143
144 af = of_bus_pci_get_flags(addr);
145 rf = of_bus_pci_get_flags(range);
146
147 /* Check address type match */
148 if ((af ^ rf) & (IORESOURCE_MEM | IORESOURCE_IO))
149 return OF_BAD_ADDR;
150
151 /* Read address values, skipping high cell */
152 cp = of_read_number(range + 1, na - 1);
153 s = of_read_number(range + na + pna, ns);
154 da = of_read_number(addr + 1, na - 1);
155
156 pr_debug("OF: PCI map, cp=%llx, s=%llx, da=%llx\n",
157 (unsigned long long)cp, (unsigned long long)s,
158 (unsigned long long)da);
159
160 if (da < cp || da >= (cp + s))
161 return OF_BAD_ADDR;
162 return da - cp;
163 }
164
165 static int of_bus_pci_translate(__be32 *addr, u64 offset, int na)
166 {
167 return of_bus_default_translate(addr + 1, offset, na - 1);
168 }
169 #endif /* CONFIG_OF_ADDRESS_PCI */
170
171 #ifdef CONFIG_PCI
172 const __be32 *of_get_pci_address(struct device_node *dev, int bar_no, u64 *size,
173 unsigned int *flags)
174 {
175 const __be32 *prop;
176 unsigned int psize;
177 struct device_node *parent;
178 struct of_bus *bus;
179 int onesize, i, na, ns;
180
181 /* Get parent & match bus type */
182 parent = of_get_parent(dev);
183 if (parent == NULL)
184 return NULL;
185 bus = of_match_bus(parent);
186 if (strcmp(bus->name, "pci")) {
187 of_node_put(parent);
188 return NULL;
189 }
190 bus->count_cells(dev, &na, &ns);
191 of_node_put(parent);
192 if (!OF_CHECK_ADDR_COUNT(na))
193 return NULL;
194
195 /* Get "reg" or "assigned-addresses" property */
196 prop = of_get_property(dev, bus->addresses, &psize);
197 if (prop == NULL)
198 return NULL;
199 psize /= 4;
200
201 onesize = na + ns;
202 for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++) {
203 u32 val = be32_to_cpu(prop[0]);
204 if ((val & 0xff) == ((bar_no * 4) + PCI_BASE_ADDRESS_0)) {
205 if (size)
206 *size = of_read_number(prop + na, ns);
207 if (flags)
208 *flags = bus->get_flags(prop);
209 return prop;
210 }
211 }
212 return NULL;
213 }
214 EXPORT_SYMBOL(of_get_pci_address);
215
216 int of_pci_address_to_resource(struct device_node *dev, int bar,
217 struct resource *r)
218 {
219 const __be32 *addrp;
220 u64 size;
221 unsigned int flags;
222
223 addrp = of_get_pci_address(dev, bar, &size, &flags);
224 if (addrp == NULL)
225 return -EINVAL;
226 return __of_address_to_resource(dev, addrp, size, flags, NULL, r);
227 }
228 EXPORT_SYMBOL_GPL(of_pci_address_to_resource);
229
230 int of_pci_range_parser_init(struct of_pci_range_parser *parser,
231 struct device_node *node)
232 {
233 const int na = 3, ns = 2;
234 int rlen;
235
236 parser->node = node;
237 parser->pna = of_n_addr_cells(node);
238 parser->np = parser->pna + na + ns;
239
240 parser->range = of_get_property(node, "ranges", &rlen);
241 if (parser->range == NULL)
242 return -ENOENT;
243
244 parser->end = parser->range + rlen / sizeof(__be32);
245
246 return 0;
247 }
248 EXPORT_SYMBOL_GPL(of_pci_range_parser_init);
249
250 struct of_pci_range *of_pci_range_parser_one(struct of_pci_range_parser *parser,
251 struct of_pci_range *range)
252 {
253 const int na = 3, ns = 2;
254
255 if (!range)
256 return NULL;
257
258 if (!parser->range || parser->range + parser->np > parser->end)
259 return NULL;
260
261 range->pci_space = parser->range[0];
262 range->flags = of_bus_pci_get_flags(parser->range);
263 range->pci_addr = of_read_number(parser->range + 1, ns);
264 range->cpu_addr = of_translate_address(parser->node,
265 parser->range + na);
266 range->size = of_read_number(parser->range + parser->pna + na, ns);
267
268 parser->range += parser->np;
269
270 /* Now consume following elements while they are contiguous */
271 while (parser->range + parser->np <= parser->end) {
272 u32 flags, pci_space;
273 u64 pci_addr, cpu_addr, size;
274
275 pci_space = be32_to_cpup(parser->range);
276 flags = of_bus_pci_get_flags(parser->range);
277 pci_addr = of_read_number(parser->range + 1, ns);
278 cpu_addr = of_translate_address(parser->node,
279 parser->range + na);
280 size = of_read_number(parser->range + parser->pna + na, ns);
281
282 if (flags != range->flags)
283 break;
284 if (pci_addr != range->pci_addr + range->size ||
285 cpu_addr != range->cpu_addr + range->size)
286 break;
287
288 range->size += size;
289 parser->range += parser->np;
290 }
291
292 return range;
293 }
294 EXPORT_SYMBOL_GPL(of_pci_range_parser_one);
295
296 #endif /* CONFIG_PCI */
297
298 /*
299 * ISA bus specific translator
300 */
301
302 static int of_bus_isa_match(struct device_node *np)
303 {
304 return !strcmp(np->name, "isa");
305 }
306
307 static void of_bus_isa_count_cells(struct device_node *child,
308 int *addrc, int *sizec)
309 {
310 if (addrc)
311 *addrc = 2;
312 if (sizec)
313 *sizec = 1;
314 }
315
316 static u64 of_bus_isa_map(__be32 *addr, const __be32 *range, int na, int ns,
317 int pna)
318 {
319 u64 cp, s, da;
320
321 /* Check address type match */
322 if ((addr[0] ^ range[0]) & cpu_to_be32(1))
323 return OF_BAD_ADDR;
324
325 /* Read address values, skipping high cell */
326 cp = of_read_number(range + 1, na - 1);
327 s = of_read_number(range + na + pna, ns);
328 da = of_read_number(addr + 1, na - 1);
329
330 pr_debug("OF: ISA map, cp=%llx, s=%llx, da=%llx\n",
331 (unsigned long long)cp, (unsigned long long)s,
332 (unsigned long long)da);
333
334 if (da < cp || da >= (cp + s))
335 return OF_BAD_ADDR;
336 return da - cp;
337 }
338
339 static int of_bus_isa_translate(__be32 *addr, u64 offset, int na)
340 {
341 return of_bus_default_translate(addr + 1, offset, na - 1);
342 }
343
344 static unsigned int of_bus_isa_get_flags(const __be32 *addr)
345 {
346 unsigned int flags = 0;
347 u32 w = be32_to_cpup(addr);
348
349 if (w & 1)
350 flags |= IORESOURCE_IO;
351 else
352 flags |= IORESOURCE_MEM;
353 return flags;
354 }
355
356 /*
357 * Array of bus specific translators
358 */
359
360 static struct of_bus of_busses[] = {
361 #ifdef CONFIG_OF_ADDRESS_PCI
362 /* PCI */
363 {
364 .name = "pci",
365 .addresses = "assigned-addresses",
366 .match = of_bus_pci_match,
367 .count_cells = of_bus_pci_count_cells,
368 .map = of_bus_pci_map,
369 .translate = of_bus_pci_translate,
370 .get_flags = of_bus_pci_get_flags,
371 },
372 #endif /* CONFIG_OF_ADDRESS_PCI */
373 /* ISA */
374 {
375 .name = "isa",
376 .addresses = "reg",
377 .match = of_bus_isa_match,
378 .count_cells = of_bus_isa_count_cells,
379 .map = of_bus_isa_map,
380 .translate = of_bus_isa_translate,
381 .get_flags = of_bus_isa_get_flags,
382 },
383 /* Default */
384 {
385 .name = "default",
386 .addresses = "reg",
387 .match = NULL,
388 .count_cells = of_bus_default_count_cells,
389 .map = of_bus_default_map,
390 .translate = of_bus_default_translate,
391 .get_flags = of_bus_default_get_flags,
392 },
393 };
394
395 static struct of_bus *of_match_bus(struct device_node *np)
396 {
397 int i;
398
399 for (i = 0; i < ARRAY_SIZE(of_busses); i++)
400 if (!of_busses[i].match || of_busses[i].match(np))
401 return &of_busses[i];
402 BUG();
403 return NULL;
404 }
405
406 static int of_translate_one(struct device_node *parent, struct of_bus *bus,
407 struct of_bus *pbus, __be32 *addr,
408 int na, int ns, int pna, const char *rprop)
409 {
410 const __be32 *ranges;
411 unsigned int rlen;
412 int rone;
413 u64 offset = OF_BAD_ADDR;
414
415 /* Normally, an absence of a "ranges" property means we are
416 * crossing a non-translatable boundary, and thus the addresses
417 * below the current not cannot be converted to CPU physical ones.
418 * Unfortunately, while this is very clear in the spec, it's not
419 * what Apple understood, and they do have things like /uni-n or
420 * /ht nodes with no "ranges" property and a lot of perfectly
421 * useable mapped devices below them. Thus we treat the absence of
422 * "ranges" as equivalent to an empty "ranges" property which means
423 * a 1:1 translation at that level. It's up to the caller not to try
424 * to translate addresses that aren't supposed to be translated in
425 * the first place. --BenH.
426 *
427 * As far as we know, this damage only exists on Apple machines, so
428 * This code is only enabled on powerpc. --gcl
429 */
430 ranges = of_get_property(parent, rprop, &rlen);
431 #if !defined(CONFIG_PPC)
432 if (ranges == NULL) {
433 pr_err("OF: no ranges; cannot translate\n");
434 return 1;
435 }
436 #endif /* !defined(CONFIG_PPC) */
437 if (ranges == NULL || rlen == 0) {
438 offset = of_read_number(addr, na);
439 memset(addr, 0, pna * 4);
440 pr_debug("OF: empty ranges; 1:1 translation\n");
441 goto finish;
442 }
443
444 pr_debug("OF: walking ranges...\n");
445
446 /* Now walk through the ranges */
447 rlen /= 4;
448 rone = na + pna + ns;
449 for (; rlen >= rone; rlen -= rone, ranges += rone) {
450 offset = bus->map(addr, ranges, na, ns, pna);
451 if (offset != OF_BAD_ADDR)
452 break;
453 }
454 if (offset == OF_BAD_ADDR) {
455 pr_debug("OF: not found !\n");
456 return 1;
457 }
458 memcpy(addr, ranges + na, 4 * pna);
459
460 finish:
461 of_dump_addr("OF: parent translation for:", addr, pna);
462 pr_debug("OF: with offset: %llx\n", (unsigned long long)offset);
463
464 /* Translate it into parent bus space */
465 return pbus->translate(addr, offset, pna);
466 }
467
468 /*
469 * Translate an address from the device-tree into a CPU physical address,
470 * this walks up the tree and applies the various bus mappings on the
471 * way.
472 *
473 * Note: We consider that crossing any level with #size-cells == 0 to mean
474 * that translation is impossible (that is we are not dealing with a value
475 * that can be mapped to a cpu physical address). This is not really specified
476 * that way, but this is traditionally the way IBM at least do things
477 */
478 static u64 __of_translate_address(struct device_node *dev,
479 const __be32 *in_addr, const char *rprop)
480 {
481 struct device_node *parent = NULL;
482 struct of_bus *bus, *pbus;
483 __be32 addr[OF_MAX_ADDR_CELLS];
484 int na, ns, pna, pns;
485 u64 result = OF_BAD_ADDR;
486
487 pr_debug("OF: ** translation for device %s **\n", of_node_full_name(dev));
488
489 /* Increase refcount at current level */
490 of_node_get(dev);
491
492 /* Get parent & match bus type */
493 parent = of_get_parent(dev);
494 if (parent == NULL)
495 goto bail;
496 bus = of_match_bus(parent);
497
498 /* Count address cells & copy address locally */
499 bus->count_cells(dev, &na, &ns);
500 if (!OF_CHECK_COUNTS(na, ns)) {
501 pr_debug("OF: Bad cell count for %s\n", of_node_full_name(dev));
502 goto bail;
503 }
504 memcpy(addr, in_addr, na * 4);
505
506 pr_debug("OF: bus is %s (na=%d, ns=%d) on %s\n",
507 bus->name, na, ns, of_node_full_name(parent));
508 of_dump_addr("OF: translating address:", addr, na);
509
510 /* Translate */
511 for (;;) {
512 /* Switch to parent bus */
513 of_node_put(dev);
514 dev = parent;
515 parent = of_get_parent(dev);
516
517 /* If root, we have finished */
518 if (parent == NULL) {
519 pr_debug("OF: reached root node\n");
520 result = of_read_number(addr, na);
521 break;
522 }
523
524 /* Get new parent bus and counts */
525 pbus = of_match_bus(parent);
526 pbus->count_cells(dev, &pna, &pns);
527 if (!OF_CHECK_COUNTS(pna, pns)) {
528 printk(KERN_ERR "prom_parse: Bad cell count for %s\n",
529 of_node_full_name(dev));
530 break;
531 }
532
533 pr_debug("OF: parent bus is %s (na=%d, ns=%d) on %s\n",
534 pbus->name, pna, pns, of_node_full_name(parent));
535
536 /* Apply bus translation */
537 if (of_translate_one(dev, bus, pbus, addr, na, ns, pna, rprop))
538 break;
539
540 /* Complete the move up one level */
541 na = pna;
542 ns = pns;
543 bus = pbus;
544
545 of_dump_addr("OF: one level translation:", addr, na);
546 }
547 bail:
548 of_node_put(parent);
549 of_node_put(dev);
550
551 return result;
552 }
553
554 u64 of_translate_address(struct device_node *dev, const __be32 *in_addr)
555 {
556 return __of_translate_address(dev, in_addr, "ranges");
557 }
558 EXPORT_SYMBOL(of_translate_address);
559
560 u64 of_translate_dma_address(struct device_node *dev, const __be32 *in_addr)
561 {
562 return __of_translate_address(dev, in_addr, "dma-ranges");
563 }
564 EXPORT_SYMBOL(of_translate_dma_address);
565
566 const __be32 *of_get_address(struct device_node *dev, int index, u64 *size,
567 unsigned int *flags)
568 {
569 const __be32 *prop;
570 unsigned int psize;
571 struct device_node *parent;
572 struct of_bus *bus;
573 int onesize, i, na, ns;
574
575 /* Get parent & match bus type */
576 parent = of_get_parent(dev);
577 if (parent == NULL)
578 return NULL;
579 bus = of_match_bus(parent);
580 bus->count_cells(dev, &na, &ns);
581 of_node_put(parent);
582 if (!OF_CHECK_ADDR_COUNT(na))
583 return NULL;
584
585 /* Get "reg" or "assigned-addresses" property */
586 prop = of_get_property(dev, bus->addresses, &psize);
587 if (prop == NULL)
588 return NULL;
589 psize /= 4;
590
591 onesize = na + ns;
592 for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
593 if (i == index) {
594 if (size)
595 *size = of_read_number(prop + na, ns);
596 if (flags)
597 *flags = bus->get_flags(prop);
598 return prop;
599 }
600 return NULL;
601 }
602 EXPORT_SYMBOL(of_get_address);
603
604 unsigned long __weak pci_address_to_pio(phys_addr_t address)
605 {
606 if (address > IO_SPACE_LIMIT)
607 return (unsigned long)-1;
608
609 return (unsigned long) address;
610 }
611
612 static int __of_address_to_resource(struct device_node *dev,
613 const __be32 *addrp, u64 size, unsigned int flags,
614 const char *name, struct resource *r)
615 {
616 u64 taddr;
617
618 if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
619 return -EINVAL;
620 taddr = of_translate_address(dev, addrp);
621 if (taddr == OF_BAD_ADDR)
622 return -EINVAL;
623 memset(r, 0, sizeof(struct resource));
624 if (flags & IORESOURCE_IO) {
625 unsigned long port;
626 port = pci_address_to_pio(taddr);
627 if (port == (unsigned long)-1)
628 return -EINVAL;
629 r->start = port;
630 r->end = port + size - 1;
631 } else {
632 r->start = taddr;
633 r->end = taddr + size - 1;
634 }
635 r->flags = flags;
636 r->name = name ? name : dev->full_name;
637
638 return 0;
639 }
640
641 /**
642 * of_address_to_resource - Translate device tree address and return as resource
643 *
644 * Note that if your address is a PIO address, the conversion will fail if
645 * the physical address can't be internally converted to an IO token with
646 * pci_address_to_pio(), that is because it's either called to early or it
647 * can't be matched to any host bridge IO space
648 */
649 int of_address_to_resource(struct device_node *dev, int index,
650 struct resource *r)
651 {
652 const __be32 *addrp;
653 u64 size;
654 unsigned int flags;
655 const char *name = NULL;
656
657 addrp = of_get_address(dev, index, &size, &flags);
658 if (addrp == NULL)
659 return -EINVAL;
660
661 /* Get optional "reg-names" property to add a name to a resource */
662 of_property_read_string_index(dev, "reg-names", index, &name);
663
664 return __of_address_to_resource(dev, addrp, size, flags, name, r);
665 }
666 EXPORT_SYMBOL_GPL(of_address_to_resource);
667
668 struct device_node *of_find_matching_node_by_address(struct device_node *from,
669 const struct of_device_id *matches,
670 u64 base_address)
671 {
672 struct device_node *dn = of_find_matching_node(from, matches);
673 struct resource res;
674
675 while (dn) {
676 if (of_address_to_resource(dn, 0, &res))
677 continue;
678 if (res.start == base_address)
679 return dn;
680 dn = of_find_matching_node(dn, matches);
681 }
682
683 return NULL;
684 }
685
686
687 /**
688 * of_iomap - Maps the memory mapped IO for a given device_node
689 * @device: the device whose io range will be mapped
690 * @index: index of the io range
691 *
692 * Returns a pointer to the mapped memory
693 */
694 void __iomem *of_iomap(struct device_node *np, int index)
695 {
696 struct resource res;
697
698 if (of_address_to_resource(np, index, &res))
699 return NULL;
700
701 return ioremap(res.start, resource_size(&res));
702 }
703 EXPORT_SYMBOL(of_iomap);
704
705 /*
706 * of_io_request_and_map - Requests a resource and maps the memory mapped IO
707 * for a given device_node
708 * @device: the device whose io range will be mapped
709 * @index: index of the io range
710 * @name: name of the resource
711 *
712 * Returns a pointer to the requested and mapped memory or an ERR_PTR() encoded
713 * error code on failure. Usage example:
714 *
715 * base = of_io_request_and_map(node, 0, "foo");
716 * if (IS_ERR(base))
717 * return PTR_ERR(base);
718 */
719 void __iomem *of_io_request_and_map(struct device_node *np, int index,
720 char *name)
721 {
722 struct resource res;
723 void __iomem *mem;
724
725 if (of_address_to_resource(np, index, &res))
726 return IOMEM_ERR_PTR(-EINVAL);
727
728 if (!request_mem_region(res.start, resource_size(&res), name))
729 return IOMEM_ERR_PTR(-EBUSY);
730
731 mem = ioremap(res.start, resource_size(&res));
732 if (!mem) {
733 release_mem_region(res.start, resource_size(&res));
734 return IOMEM_ERR_PTR(-ENOMEM);
735 }
736
737 return mem;
738 }
739 EXPORT_SYMBOL(of_io_request_and_map);
740
741 /**
742 * of_dma_get_range - Get DMA range info
743 * @np: device node to get DMA range info
744 * @dma_addr: pointer to store initial DMA address of DMA range
745 * @paddr: pointer to store initial CPU address of DMA range
746 * @size: pointer to store size of DMA range
747 *
748 * Look in bottom up direction for the first "dma-ranges" property
749 * and parse it.
750 * dma-ranges format:
751 * DMA addr (dma_addr) : naddr cells
752 * CPU addr (phys_addr_t) : pna cells
753 * size : nsize cells
754 *
755 * It returns -ENODEV if "dma-ranges" property was not found
756 * for this device in DT.
757 */
758 int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size)
759 {
760 struct device_node *node = of_node_get(np);
761 const __be32 *ranges = NULL;
762 int len, naddr, nsize, pna;
763 int ret = 0;
764 u64 dmaaddr;
765
766 if (!node)
767 return -EINVAL;
768
769 while (1) {
770 naddr = of_n_addr_cells(node);
771 nsize = of_n_size_cells(node);
772 node = of_get_next_parent(node);
773 if (!node)
774 break;
775
776 ranges = of_get_property(node, "dma-ranges", &len);
777
778 /* Ignore empty ranges, they imply no translation required */
779 if (ranges && len > 0)
780 break;
781
782 /*
783 * At least empty ranges has to be defined for parent node if
784 * DMA is supported
785 */
786 if (!ranges)
787 break;
788 }
789
790 if (!ranges) {
791 pr_debug("%s: no dma-ranges found for node(%s)\n",
792 __func__, np->full_name);
793 ret = -ENODEV;
794 goto out;
795 }
796
797 len /= sizeof(u32);
798
799 pna = of_n_addr_cells(node);
800
801 /* dma-ranges format:
802 * DMA addr : naddr cells
803 * CPU addr : pna cells
804 * size : nsize cells
805 */
806 dmaaddr = of_read_number(ranges, naddr);
807 *paddr = of_translate_dma_address(np, ranges);
808 if (*paddr == OF_BAD_ADDR) {
809 pr_err("%s: translation of DMA address(%pad) to CPU address failed node(%s)\n",
810 __func__, dma_addr, np->full_name);
811 ret = -EINVAL;
812 goto out;
813 }
814 *dma_addr = dmaaddr;
815
816 *size = of_read_number(ranges + naddr + pna, nsize);
817
818 pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
819 *dma_addr, *paddr, *size);
820
821 out:
822 of_node_put(node);
823
824 return ret;
825 }
826 EXPORT_SYMBOL_GPL(of_dma_get_range);
827
828 /**
829 * of_dma_is_coherent - Check if device is coherent
830 * @np: device node
831 *
832 * It returns true if "dma-coherent" property was found
833 * for this device in DT.
834 */
835 bool of_dma_is_coherent(struct device_node *np)
836 {
837 struct device_node *node = of_node_get(np);
838
839 while (node) {
840 if (of_property_read_bool(node, "dma-coherent")) {
841 of_node_put(node);
842 return true;
843 }
844 node = of_get_next_parent(node);
845 }
846 of_node_put(node);
847 return false;
848 }
849 EXPORT_SYMBOL_GPL(of_dma_is_coherent);
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