xref: /freebsd/sys/dev/ofw/ofw_fdt.c (revision 3f0164abf32b9b761e0a2cb4bdca3a8b84f156d4)
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/kernel.h>
35 #include <sys/malloc.h>
36 #include <sys/systm.h>
37 
38 #include <contrib/libfdt/libfdt.h>
39 
40 #include <machine/stdarg.h>
41 
42 #include <dev/fdt/fdt_common.h>
43 #include <dev/ofw/ofwvar.h>
44 #include <dev/ofw/openfirm.h>
45 
46 #include "ofw_if.h"
47 
48 #ifdef DEBUG
49 #define debugf(fmt, args...) do { printf("%s(): ", __func__);	\
50     printf(fmt,##args); } while (0)
51 #else
52 #define debugf(fmt, args...)
53 #endif
54 
55 static int ofw_fdt_init(ofw_t, void *);
56 static phandle_t ofw_fdt_peer(ofw_t, phandle_t);
57 static phandle_t ofw_fdt_child(ofw_t, phandle_t);
58 static phandle_t ofw_fdt_parent(ofw_t, phandle_t);
59 static phandle_t ofw_fdt_instance_to_package(ofw_t, ihandle_t);
60 static ssize_t ofw_fdt_getproplen(ofw_t, phandle_t, const char *);
61 static ssize_t ofw_fdt_getprop(ofw_t, phandle_t, const char *, void *, size_t);
62 static int ofw_fdt_nextprop(ofw_t, phandle_t, const char *, char *, size_t);
63 static int ofw_fdt_setprop(ofw_t, phandle_t, const char *, const void *,
64     size_t);
65 static ssize_t ofw_fdt_canon(ofw_t, const char *, char *, size_t);
66 static phandle_t ofw_fdt_finddevice(ofw_t, const char *);
67 static ssize_t ofw_fdt_instance_to_path(ofw_t, ihandle_t, char *, size_t);
68 static ssize_t ofw_fdt_package_to_path(ofw_t, phandle_t, char *, size_t);
69 static int ofw_fdt_interpret(ofw_t, const char *, int, cell_t *);
70 
71 static ofw_method_t ofw_fdt_methods[] = {
72 	OFWMETHOD(ofw_init,			ofw_fdt_init),
73 	OFWMETHOD(ofw_peer,			ofw_fdt_peer),
74 	OFWMETHOD(ofw_child,			ofw_fdt_child),
75 	OFWMETHOD(ofw_parent,			ofw_fdt_parent),
76 	OFWMETHOD(ofw_instance_to_package,	ofw_fdt_instance_to_package),
77 	OFWMETHOD(ofw_getproplen,		ofw_fdt_getproplen),
78 	OFWMETHOD(ofw_getprop,			ofw_fdt_getprop),
79 	OFWMETHOD(ofw_nextprop,			ofw_fdt_nextprop),
80 	OFWMETHOD(ofw_setprop,			ofw_fdt_setprop),
81 	OFWMETHOD(ofw_canon,			ofw_fdt_canon),
82 	OFWMETHOD(ofw_finddevice,		ofw_fdt_finddevice),
83 	OFWMETHOD(ofw_instance_to_path,		ofw_fdt_instance_to_path),
84 	OFWMETHOD(ofw_package_to_path,		ofw_fdt_package_to_path),
85 	OFWMETHOD(ofw_interpret,		ofw_fdt_interpret),
86 	{ 0, 0 }
87 };
88 
89 static ofw_def_t ofw_fdt = {
90 	OFW_FDT,
91 	ofw_fdt_methods,
92 	0
93 };
94 OFW_DEF(ofw_fdt);
95 
96 static void *fdtp = NULL;
97 
98 static int
99 ofw_fdt_init(ofw_t ofw, void *data)
100 {
101 	int err;
102 
103 	/* Check FDT blob integrity */
104 	if ((err = fdt_check_header(data)) != 0)
105 		return (err);
106 
107 	fdtp = data;
108 	return (0);
109 }
110 
111 /*
112  * Device tree functions.
113  *
114  * We use the offset from fdtp to the node as the 'phandle' in OF interface.
115  *
116  * phandle is a u32 value, therefore we cannot use the pointer to node as
117  * phandle in 64 bit. We also do not use the usual fdt offset as phandle,
118  * as it can be 0, and the OF interface has special meaning for phandle 0.
119  */
120 
121 static phandle_t
122 fdt_offset_phandle(int offset)
123 {
124 	if (offset < 0)
125 		return (0);
126 	return ((phandle_t)offset + fdt_off_dt_struct(fdtp));
127 }
128 
129 static int
130 fdt_phandle_offset(phandle_t p)
131 {
132 	int pint = (int)p;
133 	int dtoff = fdt_off_dt_struct(fdtp);
134 
135 	if (pint < dtoff)
136 		return (-1);
137 	return (pint - dtoff);
138 }
139 
140 static int
141 fdt_pointer_offset(const void *ptr)
142 {
143 	uintptr_t dt_struct, p;
144 	int offset;
145 
146 	p = (uintptr_t)ptr;
147 	dt_struct = (uintptr_t)fdtp + fdt_off_dt_struct(fdtp);
148 
149 	if ((p < dt_struct) ||
150 	    p > (dt_struct + fdt_size_dt_struct(fdtp)))
151 		return (-1);
152 
153 	offset = p - dt_struct;
154 	if (offset < 0)
155 		return (-1);
156 
157 	return (offset);
158 }
159 
160 /* Return the next sibling of this node or 0. */
161 static phandle_t
162 ofw_fdt_peer(ofw_t ofw, phandle_t node)
163 {
164 	int depth, offset;
165 
166 	if (node == 0) {
167 		/* Find root node */
168 		offset = fdt_path_offset(fdtp, "/");
169 
170 		return (fdt_offset_phandle(offset));
171 	}
172 
173 	offset = fdt_phandle_offset(node);
174 	if (offset < 0)
175 		return (0);
176 
177 	for (depth = 1, offset = fdt_next_node(fdtp, offset, &depth);
178 	    offset >= 0;
179 	    offset = fdt_next_node(fdtp, offset, &depth)) {
180 		if (depth < 0)
181 			return (0);
182 		if (depth == 1)
183 			return (fdt_offset_phandle(offset));
184 	}
185 
186 	return (0);
187 }
188 
189 /* Return the first child of this node or 0. */
190 static phandle_t
191 ofw_fdt_child(ofw_t ofw, phandle_t node)
192 {
193 	int depth, offset;
194 
195 	offset = fdt_phandle_offset(node);
196 	if (offset < 0)
197 		return (0);
198 
199 	for (depth = 0, offset = fdt_next_node(fdtp, offset, &depth);
200 	    (offset >= 0) && (depth > 0);
201 	    offset = fdt_next_node(fdtp, offset, &depth)) {
202 		if (depth < 0)
203 			return (0);
204 		if (depth == 1)
205 			return (fdt_offset_phandle(offset));
206 	}
207 
208 	return (0);
209 }
210 
211 /* Return the parent of this node or 0. */
212 static phandle_t
213 ofw_fdt_parent(ofw_t ofw, phandle_t node)
214 {
215 	int offset, paroffset;
216 
217 	offset = fdt_phandle_offset(node);
218 	if (offset < 0)
219 		return (0);
220 
221 	paroffset = fdt_parent_offset(fdtp, offset);
222 	return (fdt_offset_phandle(paroffset));
223 }
224 
225 /* Return the package handle that corresponds to an instance handle. */
226 static phandle_t
227 ofw_fdt_instance_to_package(ofw_t ofw, ihandle_t instance)
228 {
229 	int offset;
230 
231 	/*
232 	 * Note: FDT does not have the notion of instances, but we somewhat
233 	 * abuse the semantics and let treat as 'instance' the internal
234 	 * 'phandle' prop, so that ofw I/F consumers have a uniform way of
235 	 * translation between internal representation (which appear in some
236 	 * contexts as property values) and effective phandles.
237 	 */
238 	offset = fdt_node_offset_by_phandle(fdtp, instance);
239 	if (offset < 0)
240 		return (-1);
241 
242 	return (fdt_offset_phandle(offset));
243 }
244 
245 /* Get the length of a property of a package. */
246 static ssize_t
247 ofw_fdt_getproplen(ofw_t ofw, phandle_t package, const char *propname)
248 {
249 	const struct fdt_property *prop;
250 	int offset, len;
251 
252 	offset = fdt_phandle_offset(package);
253 	if (offset < 0)
254 		return (-1);
255 
256 	if (strcmp(propname, "name") == 0) {
257 		/* Emulate the 'name' property */
258 		fdt_get_name(fdtp, offset, &len);
259 		return (len + 1);
260 	}
261 
262 	len = -1;
263 	prop = fdt_get_property(fdtp, offset, propname, &len);
264 
265 	return (len);
266 }
267 
268 /* Get the value of a property of a package. */
269 static ssize_t
270 ofw_fdt_getprop(ofw_t ofw, phandle_t package, const char *propname, void *buf,
271     size_t buflen)
272 {
273 	const void *prop;
274 	const char *name;
275 	int len, offset;
276 
277 	offset = fdt_phandle_offset(package);
278 	if (offset < 0)
279 		return (-1);
280 
281 	if (strcmp(propname, "name") == 0) {
282 		/* Emulate the 'name' property */
283 		name = fdt_get_name(fdtp, offset, &len);
284 		strncpy(buf, name, buflen);
285 		if (len + 1 > buflen)
286 			len = buflen;
287 		return (len + 1);
288 	}
289 
290 	prop = fdt_getprop(fdtp, offset, propname, &len);
291 	if (prop == NULL)
292 		return (-1);
293 
294 	if (len > buflen)
295 		len = buflen;
296 	bcopy(prop, buf, len);
297 	return (len);
298 }
299 
300 static int
301 fdt_nextprop(int offset, char *buf, size_t size)
302 {
303 	const struct fdt_property *prop;
304 	const char *name;
305 	uint32_t tag;
306 	int nextoffset, depth;
307 
308 	depth = 0;
309 	tag = fdt_next_tag(fdtp, offset, &nextoffset);
310 
311 	/* Find the next prop */
312 	do {
313 		offset = nextoffset;
314 		tag = fdt_next_tag(fdtp, offset, &nextoffset);
315 
316 		if (tag == FDT_BEGIN_NODE)
317 			depth++;
318 		else if (tag == FDT_END_NODE)
319 			depth--;
320 		else if ((tag == FDT_PROP) && (depth == 0)) {
321 			prop =
322 			    (const struct fdt_property *)fdt_offset_ptr(fdtp,
323 			    offset, sizeof(*prop));
324 			name = fdt_string(fdtp,
325 			    fdt32_to_cpu(prop->nameoff));
326 			strncpy(buf, name, size);
327 			return (strlen(name));
328 		} else
329 			depth = -1;
330 	} while (depth >= 0);
331 
332 	return (-1);
333 }
334 
335 /*
336  * Get the next property of a package. Return the actual len of retrieved
337  * prop name.
338  */
339 static int
340 ofw_fdt_nextprop(ofw_t ofw, phandle_t package, const char *previous, char *buf,
341     size_t size)
342 {
343 	const struct fdt_property *prop;
344 	int offset, rv;
345 
346 	offset = fdt_phandle_offset(package);
347 	if (offset < 0)
348 		return (-1);
349 
350 	if (previous == NULL)
351 		/* Find the first prop in the node */
352 		return (fdt_nextprop(offset, buf, size));
353 
354 	/*
355 	 * Advance to the previous prop
356 	 */
357 	prop = fdt_get_property(fdtp, offset, previous, NULL);
358 	if (prop == NULL)
359 		return (-1);
360 
361 	offset = fdt_pointer_offset(prop);
362 	rv = fdt_nextprop(offset, buf, size);
363 	return (rv);
364 }
365 
366 /* Set the value of a property of a package. */
367 static int
368 ofw_fdt_setprop(ofw_t ofw, phandle_t package, const char *propname,
369     const void *buf, size_t len)
370 {
371 	int offset;
372 
373 	offset = fdt_phandle_offset(package);
374 	if (offset < 0)
375 		return (-1);
376 
377 	return (fdt_setprop_inplace(fdtp, offset, propname, buf, len));
378 }
379 
380 /* Convert a device specifier to a fully qualified pathname. */
381 static ssize_t
382 ofw_fdt_canon(ofw_t ofw, const char *device, char *buf, size_t len)
383 {
384 
385 	return (-1);
386 }
387 
388 /* Return a package handle for the specified device. */
389 static phandle_t
390 ofw_fdt_finddevice(ofw_t ofw, const char *device)
391 {
392 	int offset;
393 
394 	offset = fdt_path_offset(fdtp, device);
395 	if (offset < 0)
396 		return (-1);
397 	return (fdt_offset_phandle(offset));
398 }
399 
400 /* Return the fully qualified pathname corresponding to an instance. */
401 static ssize_t
402 ofw_fdt_instance_to_path(ofw_t ofw, ihandle_t instance, char *buf, size_t len)
403 {
404 
405 	return (-1);
406 }
407 
408 /* Return the fully qualified pathname corresponding to a package. */
409 static ssize_t
410 ofw_fdt_package_to_path(ofw_t ofw, phandle_t package, char *buf, size_t len)
411 {
412 
413 	return (-1);
414 }
415 
416 static int
417 ofw_fdt_fixup(ofw_t ofw)
418 {
419 #define FDT_MODEL_LEN	80
420 	char model[FDT_MODEL_LEN];
421 	phandle_t root;
422 	ssize_t len;
423 	int i;
424 
425 	if ((root = ofw_fdt_finddevice(ofw, "/")) == -1)
426 		return (ENODEV);
427 
428 	if ((len = ofw_fdt_getproplen(ofw, root, "model")) <= 0)
429 		return (0);
430 
431 	bzero(model, FDT_MODEL_LEN);
432 	if (ofw_fdt_getprop(ofw, root, "model", model, FDT_MODEL_LEN) <= 0)
433 		return (0);
434 
435 	/*
436 	 * Search fixup table and call handler if appropriate.
437 	 */
438 	for (i = 0; fdt_fixup_table[i].model != NULL; i++) {
439 		if (strncmp(model, fdt_fixup_table[i].model,
440 		    FDT_MODEL_LEN) != 0)
441 			continue;
442 
443 		if (fdt_fixup_table[i].handler != NULL)
444 			(*fdt_fixup_table[i].handler)(root);
445 	}
446 
447 	return (0);
448 }
449 
450 static int
451 ofw_fdt_interpret(ofw_t ofw, const char *cmd, int nret, cell_t *retvals)
452 {
453 	int rv;
454 
455 	/*
456 	 * Note: FDT does not have the possibility to 'interpret' commands,
457 	 * but we abuse the interface a bit to use it for doing non-standard
458 	 * operations on the device tree blob.
459 	 *
460 	 * Currently the only supported 'command' is to trigger performing
461 	 * fixups.
462 	 */
463 	if (strncmp("perform-fixup", cmd, 13) != 0)
464 		return (0);
465 
466 	rv = ofw_fdt_fixup(ofw);
467 	if (nret > 0)
468 		retvals[0] = rv;
469 
470 	return (rv);
471 }
472