xref: /freebsd/sys/dev/fdt/fdt_common.c (revision 6574b8ed19b093f0af09501d2c9676c28993cb97)
1 /*-
2  * Copyright (c) 2009-2010 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Semihalf under sponsorship from
6  * the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 #include <sys/bus.h>
38 #include <sys/limits.h>
39 
40 #include <machine/resource.h>
41 
42 #include <dev/fdt/fdt_common.h>
43 #include <dev/ofw/ofw_bus.h>
44 #include <dev/ofw/ofw_bus_subr.h>
45 #include <dev/ofw/openfirm.h>
46 
47 #include "ofw_bus_if.h"
48 
49 #ifdef DEBUG
50 #define debugf(fmt, args...) do { printf("%s(): ", __func__);	\
51     printf(fmt,##args); } while (0)
52 #else
53 #define debugf(fmt, args...)
54 #endif
55 
56 #define FDT_COMPAT_LEN	255
57 #define FDT_TYPE_LEN	64
58 
59 #define FDT_REG_CELLS	4
60 
61 vm_paddr_t fdt_immr_pa;
62 vm_offset_t fdt_immr_va;
63 vm_offset_t fdt_immr_size;
64 
65 struct fdt_ic_list fdt_ic_list_head = SLIST_HEAD_INITIALIZER(fdt_ic_list_head);
66 
67 int
68 fdt_get_range(phandle_t node, int range_id, u_long *base, u_long *size)
69 {
70 	pcell_t ranges[6], *rangesptr;
71 	pcell_t addr_cells, size_cells, par_addr_cells;
72 	int len, tuple_size, tuples;
73 
74 	if ((fdt_addrsize_cells(node, &addr_cells, &size_cells)) != 0)
75 		return (ENXIO);
76 	/*
77 	 * Process 'ranges' property.
78 	 */
79 	par_addr_cells = fdt_parent_addr_cells(node);
80 	if (par_addr_cells > 2)
81 		return (ERANGE);
82 
83 	len = OF_getproplen(node, "ranges");
84 	if (len > sizeof(ranges))
85 		return (ENOMEM);
86 	if (len == 0) {
87 		*base = 0;
88 		*size = ULONG_MAX;
89 		return (0);
90 	}
91 
92 	if (!(range_id < len))
93 		return (ERANGE);
94 
95 	if (OF_getprop(node, "ranges", ranges, sizeof(ranges)) <= 0)
96 		return (EINVAL);
97 
98 	tuple_size = sizeof(pcell_t) * (addr_cells + par_addr_cells +
99 	    size_cells);
100 	tuples = len / tuple_size;
101 
102 	if (fdt_ranges_verify(ranges, tuples, par_addr_cells,
103 	    addr_cells, size_cells)) {
104 		return (ERANGE);
105 	}
106 	*base = 0;
107 	*size = 0;
108 	rangesptr = &ranges[range_id];
109 
110 	*base = fdt_data_get((void *)rangesptr, addr_cells);
111 	rangesptr += addr_cells;
112 	*base += fdt_data_get((void *)rangesptr, par_addr_cells);
113 	rangesptr += par_addr_cells;
114 	*size = fdt_data_get((void *)rangesptr, size_cells);
115 	return (0);
116 }
117 
118 int
119 fdt_immr_addr(vm_offset_t immr_va)
120 {
121 	phandle_t node;
122 	u_long base, size;
123 	int r;
124 
125 	/*
126 	 * Try to access the SOC node directly i.e. through /aliases/.
127 	 */
128 	if ((node = OF_finddevice("soc")) != 0)
129 		if (fdt_is_compatible_strict(node, "simple-bus"))
130 			goto moveon;
131 	/*
132 	 * Find the node the long way.
133 	 */
134 	if ((node = OF_finddevice("/")) == 0)
135 		return (ENXIO);
136 
137 	if ((node = fdt_find_compatible(node, "simple-bus", 1)) == 0)
138 		return (ENXIO);
139 
140 moveon:
141 	if ((r = fdt_get_range(node, 0, &base, &size)) == 0) {
142 		fdt_immr_pa = base;
143 		fdt_immr_va = immr_va;
144 		fdt_immr_size = size;
145 	}
146 
147 	return (r);
148 }
149 
150 /*
151  * This routine is an early-usage version of the ofw_bus_is_compatible() when
152  * the ofw_bus I/F is not available (like early console routines and similar).
153  * Note the buffer has to be on the stack since malloc() is usually not
154  * available in such cases either.
155  */
156 int
157 fdt_is_compatible(phandle_t node, const char *compatstr)
158 {
159 	char buf[FDT_COMPAT_LEN];
160 	char *compat;
161 	int len, onelen, l, rv;
162 
163 	if ((len = OF_getproplen(node, "compatible")) <= 0)
164 		return (0);
165 
166 	compat = (char *)&buf;
167 	bzero(compat, FDT_COMPAT_LEN);
168 
169 	if (OF_getprop(node, "compatible", compat, FDT_COMPAT_LEN) < 0)
170 		return (0);
171 
172 	onelen = strlen(compatstr);
173 	rv = 0;
174 	while (len > 0) {
175 		if (strncasecmp(compat, compatstr, onelen) == 0) {
176 			/* Found it. */
177 			rv = 1;
178 			break;
179 		}
180 		/* Slide to the next sub-string. */
181 		l = strlen(compat) + 1;
182 		compat += l;
183 		len -= l;
184 	}
185 
186 	return (rv);
187 }
188 
189 int
190 fdt_is_compatible_strict(phandle_t node, const char *compatible)
191 {
192 	char compat[FDT_COMPAT_LEN];
193 
194 	if (OF_getproplen(node, "compatible") <= 0)
195 		return (0);
196 
197 	if (OF_getprop(node, "compatible", compat, FDT_COMPAT_LEN) < 0)
198 		return (0);
199 
200 	if (strncasecmp(compat, compatible, FDT_COMPAT_LEN) == 0)
201 		/* This fits. */
202 		return (1);
203 
204 	return (0);
205 }
206 
207 phandle_t
208 fdt_find_compatible(phandle_t start, const char *compat, int strict)
209 {
210 	phandle_t child;
211 
212 	/*
213 	 * Traverse all children of 'start' node, and find first with
214 	 * matching 'compatible' property.
215 	 */
216 	for (child = OF_child(start); child != 0; child = OF_peer(child))
217 		if (fdt_is_compatible(child, compat)) {
218 			if (strict)
219 				if (!fdt_is_compatible_strict(child, compat))
220 					continue;
221 			return (child);
222 		}
223 	return (0);
224 }
225 
226 phandle_t
227 fdt_depth_search_compatible(phandle_t start, const char *compat, int strict)
228 {
229 	phandle_t child, node;
230 
231 	/*
232 	 * Depth-search all descendants of 'start' node, and find first with
233 	 * matching 'compatible' property.
234 	 */
235 	for (node = OF_child(start); node != 0; node = OF_peer(node)) {
236 		if (fdt_is_compatible(node, compat) &&
237 		    (strict == 0 || fdt_is_compatible_strict(node, compat))) {
238 			return (node);
239 		}
240 		child = fdt_depth_search_compatible(node, compat, strict);
241 		if (child != 0)
242 			return (child);
243 	}
244 	return (0);
245 }
246 
247 int
248 fdt_is_enabled(phandle_t node)
249 {
250 	char *stat;
251 	int ena, len;
252 
253 	len = OF_getprop_alloc(node, "status", sizeof(char),
254 	    (void **)&stat);
255 
256 	if (len <= 0)
257 		/* It is OK if no 'status' property. */
258 		return (1);
259 
260 	/* Anything other than 'okay' means disabled. */
261 	ena = 0;
262 	if (strncmp((char *)stat, "okay", len) == 0)
263 		ena = 1;
264 
265 	free(stat, M_OFWPROP);
266 	return (ena);
267 }
268 
269 int
270 fdt_is_type(phandle_t node, const char *typestr)
271 {
272 	char type[FDT_TYPE_LEN];
273 
274 	if (OF_getproplen(node, "device_type") <= 0)
275 		return (0);
276 
277 	if (OF_getprop(node, "device_type", type, FDT_TYPE_LEN) < 0)
278 		return (0);
279 
280 	if (strncasecmp(type, typestr, FDT_TYPE_LEN) == 0)
281 		/* This fits. */
282 		return (1);
283 
284 	return (0);
285 }
286 
287 int
288 fdt_parent_addr_cells(phandle_t node)
289 {
290 	pcell_t addr_cells;
291 
292 	/* Find out #address-cells of the superior bus. */
293 	if (OF_searchprop(OF_parent(node), "#address-cells", &addr_cells,
294 	    sizeof(addr_cells)) <= 0)
295 		addr_cells = 2;
296 
297 	return ((int)fdt32_to_cpu(addr_cells));
298 }
299 
300 int
301 fdt_data_verify(void *data, int cells)
302 {
303 	uint64_t d64;
304 
305 	if (cells > 1) {
306 		d64 = fdt64_to_cpu(*((uint64_t *)data));
307 		if (((d64 >> 32) & 0xffffffffull) != 0 || cells > 2)
308 			return (ERANGE);
309 	}
310 
311 	return (0);
312 }
313 
314 int
315 fdt_pm_is_enabled(phandle_t node)
316 {
317 	int ret;
318 
319 	ret = 1;
320 
321 #if defined(SOC_MV_KIRKWOOD) || defined(SOC_MV_DISCOVERY)
322 	ret = fdt_pm(node);
323 #endif
324 	return (ret);
325 }
326 
327 u_long
328 fdt_data_get(void *data, int cells)
329 {
330 
331 	if (cells == 1)
332 		return (fdt32_to_cpu(*((uint32_t *)data)));
333 
334 	return (fdt64_to_cpu(*((uint64_t *)data)));
335 }
336 
337 int
338 fdt_addrsize_cells(phandle_t node, int *addr_cells, int *size_cells)
339 {
340 	pcell_t cell;
341 	int cell_size;
342 
343 	/*
344 	 * Retrieve #{address,size}-cells.
345 	 */
346 	cell_size = sizeof(cell);
347 	if (OF_getprop(node, "#address-cells", &cell, cell_size) < cell_size)
348 		cell = 2;
349 	*addr_cells = fdt32_to_cpu((int)cell);
350 
351 	if (OF_getprop(node, "#size-cells", &cell, cell_size) < cell_size)
352 		cell = 1;
353 	*size_cells = fdt32_to_cpu((int)cell);
354 
355 	if (*addr_cells > 3 || *size_cells > 2)
356 		return (ERANGE);
357 	return (0);
358 }
359 
360 int
361 fdt_ranges_verify(pcell_t *ranges, int tuples, int par_addr_cells,
362     int this_addr_cells, int this_size_cells)
363 {
364 	int i, rv, ulsz;
365 
366 	if (par_addr_cells > 2 || this_addr_cells > 2 || this_size_cells > 2)
367 		return (ERANGE);
368 
369 	/*
370 	 * This is the max size the resource manager can handle for addresses
371 	 * and sizes.
372 	 */
373 	ulsz = sizeof(u_long);
374 	if (par_addr_cells <= ulsz && this_addr_cells <= ulsz &&
375 	    this_size_cells <= ulsz)
376 		/* We can handle everything */
377 		return (0);
378 
379 	rv = 0;
380 	for (i = 0; i < tuples; i++) {
381 
382 		if (fdt_data_verify((void *)ranges, par_addr_cells))
383 			goto err;
384 		ranges += par_addr_cells;
385 
386 		if (fdt_data_verify((void *)ranges, this_addr_cells))
387 			goto err;
388 		ranges += this_addr_cells;
389 
390 		if (fdt_data_verify((void *)ranges, this_size_cells))
391 			goto err;
392 		ranges += this_size_cells;
393 	}
394 
395 	return (0);
396 
397 err:
398 	debugf("using address range >%d-bit not supported\n", ulsz * 8);
399 	return (ERANGE);
400 }
401 
402 int
403 fdt_data_to_res(pcell_t *data, int addr_cells, int size_cells, u_long *start,
404     u_long *count)
405 {
406 
407 	/* Address portion. */
408 	if (fdt_data_verify((void *)data, addr_cells))
409 		return (ERANGE);
410 
411 	*start = fdt_data_get((void *)data, addr_cells);
412 	data += addr_cells;
413 
414 	/* Size portion. */
415 	if (fdt_data_verify((void *)data, size_cells))
416 		return (ERANGE);
417 
418 	*count = fdt_data_get((void *)data, size_cells);
419 	return (0);
420 }
421 
422 int
423 fdt_regsize(phandle_t node, u_long *base, u_long *size)
424 {
425 	pcell_t reg[4];
426 	int addr_cells, len, size_cells;
427 
428 	if (fdt_addrsize_cells(OF_parent(node), &addr_cells, &size_cells))
429 		return (ENXIO);
430 
431 	if ((sizeof(pcell_t) * (addr_cells + size_cells)) > sizeof(reg))
432 		return (ENOMEM);
433 
434 	len = OF_getprop(node, "reg", &reg, sizeof(reg));
435 	if (len <= 0)
436 		return (EINVAL);
437 
438 	*base = fdt_data_get(&reg[0], addr_cells);
439 	*size = fdt_data_get(&reg[addr_cells], size_cells);
440 	return (0);
441 }
442 
443 int
444 fdt_reg_to_rl(phandle_t node, struct resource_list *rl)
445 {
446 	u_long end, count, start;
447 	pcell_t *reg, *regptr;
448 	pcell_t addr_cells, size_cells;
449 	int tuple_size, tuples;
450 	int i, rv;
451 	long busaddr, bussize;
452 
453 	if (fdt_addrsize_cells(OF_parent(node), &addr_cells, &size_cells) != 0)
454 		return (ENXIO);
455 	if (fdt_get_range(OF_parent(node), 0, &busaddr, &bussize)) {
456 		busaddr = 0;
457 		bussize = 0;
458 	}
459 
460 	tuple_size = sizeof(pcell_t) * (addr_cells + size_cells);
461 	tuples = OF_getprop_alloc(node, "reg", tuple_size, (void **)&reg);
462 	debugf("addr_cells = %d, size_cells = %d\n", addr_cells, size_cells);
463 	debugf("tuples = %d, tuple size = %d\n", tuples, tuple_size);
464 	if (tuples <= 0)
465 		/* No 'reg' property in this node. */
466 		return (0);
467 
468 	regptr = reg;
469 	for (i = 0; i < tuples; i++) {
470 
471 		rv = fdt_data_to_res(reg, addr_cells, size_cells, &start,
472 		    &count);
473 		if (rv != 0) {
474 			resource_list_free(rl);
475 			goto out;
476 		}
477 		reg += addr_cells + size_cells;
478 
479 		/* Calculate address range relative to base. */
480 		start += busaddr;
481 		end = start + count - 1;
482 
483 		debugf("reg addr start = %lx, end = %lx, count = %lx\n", start,
484 		    end, count);
485 
486 		resource_list_add(rl, SYS_RES_MEMORY, i, start, end,
487 		    count);
488 	}
489 	rv = 0;
490 
491 out:
492 	free(regptr, M_OFWPROP);
493 	return (rv);
494 }
495 
496 int
497 fdt_intr_to_rl(device_t dev, phandle_t node, struct resource_list *rl,
498     struct fdt_sense_level *intr_sl)
499 {
500 	phandle_t iparent;
501 	uint32_t *intr, icells;
502 	int nintr, i, k;
503 
504 	nintr = OF_getencprop_alloc(node, "interrupts",  sizeof(*intr),
505 	    (void **)&intr);
506 	if (nintr > 0) {
507 		if (OF_searchencprop(node, "interrupt-parent", &iparent,
508 		    sizeof(iparent)) == -1) {
509 			device_printf(dev, "No interrupt-parent found, "
510 			    "assuming direct parent\n");
511 			iparent = OF_parent(node);
512 		}
513 		if (OF_searchencprop(OF_node_from_xref(iparent),
514 		    "#interrupt-cells", &icells, sizeof(icells)) == -1) {
515 			device_printf(dev, "Missing #interrupt-cells property, "
516 			    "assuming <1>\n");
517 			icells = 1;
518 		}
519 		if (icells < 1 || icells > nintr) {
520 			device_printf(dev, "Invalid #interrupt-cells property "
521 			    "value <%d>, assuming <1>\n", icells);
522 			icells = 1;
523 		}
524 		for (i = 0, k = 0; i < nintr; i += icells, k++) {
525 			intr[i] = ofw_bus_map_intr(dev, iparent, icells,
526 			    &intr[i]);
527 			resource_list_add(rl, SYS_RES_IRQ, k, intr[i], intr[i],
528 			    1);
529 		}
530 		free(intr, M_OFWPROP);
531 	}
532 
533 	return (0);
534 }
535 
536 int
537 fdt_get_phyaddr(phandle_t node, device_t dev, int *phy_addr, void **phy_sc)
538 {
539 	phandle_t phy_node;
540 	pcell_t phy_handle, phy_reg;
541 	uint32_t i;
542 	device_t parent, child;
543 
544 	if (OF_getencprop(node, "phy-handle", (void *)&phy_handle,
545 	    sizeof(phy_handle)) <= 0)
546 		return (ENXIO);
547 
548 	phy_node = OF_node_from_xref(phy_handle);
549 
550 	if (OF_getprop(phy_node, "reg", (void *)&phy_reg,
551 	    sizeof(phy_reg)) <= 0)
552 		return (ENXIO);
553 
554 	*phy_addr = fdt32_to_cpu(phy_reg);
555 
556 	/*
557 	 * Search for softc used to communicate with phy.
558 	 */
559 
560 	/*
561 	 * Step 1: Search for ancestor of the phy-node with a "phy-handle"
562 	 * property set.
563 	 */
564 	phy_node = OF_parent(phy_node);
565 	while (phy_node != 0) {
566 		if (OF_getprop(phy_node, "phy-handle", (void *)&phy_handle,
567 		    sizeof(phy_handle)) > 0)
568 			break;
569 		phy_node = OF_parent(phy_node);
570 	}
571 	if (phy_node == 0)
572 		return (ENXIO);
573 
574 	/*
575 	 * Step 2: For each device with the same parent and name as ours
576 	 * compare its node with the one found in step 1, ancestor of phy
577 	 * node (stored in phy_node).
578 	 */
579 	parent = device_get_parent(dev);
580 	i = 0;
581 	child = device_find_child(parent, device_get_name(dev), i);
582 	while (child != NULL) {
583 		if (ofw_bus_get_node(child) == phy_node)
584 			break;
585 		i++;
586 		child = device_find_child(parent, device_get_name(dev), i);
587 	}
588 	if (child == NULL)
589 		return (ENXIO);
590 
591 	/*
592 	 * Use softc of the device found.
593 	 */
594 	*phy_sc = (void *)device_get_softc(child);
595 
596 	return (0);
597 }
598 
599 int
600 fdt_get_reserved_regions(struct mem_region *mr, int *mrcnt)
601 {
602 	pcell_t reserve[FDT_REG_CELLS * FDT_MEM_REGIONS];
603 	pcell_t *reservep;
604 	phandle_t memory, root;
605 	uint32_t memory_size;
606 	int addr_cells, size_cells;
607 	int i, max_size, res_len, rv, tuple_size, tuples;
608 
609 	max_size = sizeof(reserve);
610 	root = OF_finddevice("/");
611 	memory = OF_finddevice("/memory");
612 	if (memory == -1) {
613 		rv = ENXIO;
614 		goto out;
615 	}
616 
617 	if ((rv = fdt_addrsize_cells(OF_parent(memory), &addr_cells,
618 	    &size_cells)) != 0)
619 		goto out;
620 
621 	if (addr_cells > 2) {
622 		rv = ERANGE;
623 		goto out;
624 	}
625 
626 	tuple_size = sizeof(pcell_t) * (addr_cells + size_cells);
627 
628 	res_len = OF_getproplen(root, "memreserve");
629 	if (res_len <= 0 || res_len > sizeof(reserve)) {
630 		rv = ERANGE;
631 		goto out;
632 	}
633 
634 	if (OF_getprop(root, "memreserve", reserve, res_len) <= 0) {
635 		rv = ENXIO;
636 		goto out;
637 	}
638 
639 	memory_size = 0;
640 	tuples = res_len / tuple_size;
641 	reservep = (pcell_t *)&reserve;
642 	for (i = 0; i < tuples; i++) {
643 
644 		rv = fdt_data_to_res(reservep, addr_cells, size_cells,
645 			(u_long *)&mr[i].mr_start, (u_long *)&mr[i].mr_size);
646 
647 		if (rv != 0)
648 			goto out;
649 
650 		reservep += addr_cells + size_cells;
651 	}
652 
653 	*mrcnt = i;
654 	rv = 0;
655 out:
656 	return (rv);
657 }
658 
659 int
660 fdt_get_mem_regions(struct mem_region *mr, int *mrcnt, uint32_t *memsize)
661 {
662 	pcell_t reg[FDT_REG_CELLS * FDT_MEM_REGIONS];
663 	pcell_t *regp;
664 	phandle_t memory;
665 	uint32_t memory_size;
666 	int addr_cells, size_cells;
667 	int i, max_size, reg_len, rv, tuple_size, tuples;
668 
669 	max_size = sizeof(reg);
670 	memory = OF_finddevice("/memory");
671 	if (memory == -1) {
672 		rv = ENXIO;
673 		goto out;
674 	}
675 
676 	if ((rv = fdt_addrsize_cells(OF_parent(memory), &addr_cells,
677 	    &size_cells)) != 0)
678 		goto out;
679 
680 	if (addr_cells > 2) {
681 		rv = ERANGE;
682 		goto out;
683 	}
684 
685 	tuple_size = sizeof(pcell_t) * (addr_cells + size_cells);
686 	reg_len = OF_getproplen(memory, "reg");
687 	if (reg_len <= 0 || reg_len > sizeof(reg)) {
688 		rv = ERANGE;
689 		goto out;
690 	}
691 
692 	if (OF_getprop(memory, "reg", reg, reg_len) <= 0) {
693 		rv = ENXIO;
694 		goto out;
695 	}
696 
697 	memory_size = 0;
698 	tuples = reg_len / tuple_size;
699 	regp = (pcell_t *)&reg;
700 	for (i = 0; i < tuples; i++) {
701 
702 		rv = fdt_data_to_res(regp, addr_cells, size_cells,
703 			(u_long *)&mr[i].mr_start, (u_long *)&mr[i].mr_size);
704 
705 		if (rv != 0)
706 			goto out;
707 
708 		regp += addr_cells + size_cells;
709 		memory_size += mr[i].mr_size;
710 	}
711 
712 	if (memory_size == 0) {
713 		rv = ERANGE;
714 		goto out;
715 	}
716 
717 	*mrcnt = i;
718 	*memsize = memory_size;
719 	rv = 0;
720 out:
721 	return (rv);
722 }
723 
724 int
725 fdt_get_unit(device_t dev)
726 {
727 	const char * name;
728 
729 	name = ofw_bus_get_name(dev);
730 	name = strchr(name, '@') + 1;
731 
732 	return (strtol(name,NULL,0));
733 }
734