xref: /freebsd/sys/dev/ofw/ofw_fdt.c (revision 10b9d77bf1ccf2f3affafa6261692cb92cf7e992)
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 
115 static int
116 fdt_phandle_offset(phandle_t p)
117 {
118 	const char *dt_struct;
119 	int offset;
120 
121 	dt_struct = (const char *)fdtp + fdt_off_dt_struct(fdtp);
122 
123 	if (((const char *)p < dt_struct) ||
124 	    (const char *)p > (dt_struct + fdt_size_dt_struct(fdtp)))
125 		return (-1);
126 
127 	offset = (const char *)p - dt_struct;
128 	if (offset < 0)
129 		return (-1);
130 
131 	return (offset);
132 }
133 
134 /* Return the next sibling of this node or 0. */
135 static phandle_t
136 ofw_fdt_peer(ofw_t ofw, phandle_t node)
137 {
138 	phandle_t p;
139 	int depth, offset;
140 
141 	if (node == 0) {
142 		/* Find root node */
143 		offset = fdt_path_offset(fdtp, "/");
144 		p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
145 
146 		return (p);
147 	}
148 
149 	offset = fdt_phandle_offset(node);
150 	if (offset < 0)
151 		return (0);
152 
153 	for (depth = 1, offset = fdt_next_node(fdtp, offset, &depth);
154 	    offset >= 0;
155 	    offset = fdt_next_node(fdtp, offset, &depth)) {
156 		if (depth < 0)
157 			return (0);
158 		if (depth == 1) {
159 			p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
160 			return (p);
161 		}
162 	}
163 
164 	return (0);
165 }
166 
167 /* Return the first child of this node or 0. */
168 static phandle_t
169 ofw_fdt_child(ofw_t ofw, phandle_t node)
170 {
171 	phandle_t p;
172 	int depth, offset;
173 
174 	offset = fdt_phandle_offset(node);
175 	if (offset < 0)
176 		return (0);
177 
178 	for (depth = 0, offset = fdt_next_node(fdtp, offset, &depth);
179 	    (offset >= 0) && (depth > 0);
180 	    offset = fdt_next_node(fdtp, offset, &depth)) {
181 		if (depth < 0)
182 			return (0);
183 		if (depth == 1) {
184 			p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
185 			return (p);
186 		}
187 	}
188 
189 	return (0);
190 }
191 
192 /* Return the parent of this node or 0. */
193 static phandle_t
194 ofw_fdt_parent(ofw_t ofw, phandle_t node)
195 {
196 	phandle_t p;
197 	int offset, paroffset;
198 
199 	offset = fdt_phandle_offset(node);
200 	if (offset < 0)
201 		return (0);
202 
203 	paroffset = fdt_parent_offset(fdtp, offset);
204 	p = (phandle_t)fdt_offset_ptr(fdtp, paroffset, sizeof(phandle_t));
205 	return (p);
206 }
207 
208 /* Return the package handle that corresponds to an instance handle. */
209 static phandle_t
210 ofw_fdt_instance_to_package(ofw_t ofw, ihandle_t instance)
211 {
212 	phandle_t p;
213 	int offset;
214 
215 	/*
216 	 * Note: FDT does not have the notion of instances, but we somewhat
217 	 * abuse the semantics and let treat as 'instance' the internal
218 	 * 'phandle' prop, so that ofw I/F consumers have a uniform way of
219 	 * translation between internal representation (which appear in some
220 	 * contexts as property values) and effective phandles.
221 	 */
222 	offset = fdt_node_offset_by_phandle(fdtp, instance);
223 	if (offset < 0)
224 		return (-1);
225 
226 	p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(phandle_t));
227 	return (p);
228 }
229 
230 /* Get the length of a property of a package. */
231 static ssize_t
232 ofw_fdt_getproplen(ofw_t ofw, phandle_t package, const char *propname)
233 {
234 	const struct fdt_property *prop;
235 	int offset, len;
236 
237 	offset = fdt_phandle_offset(package);
238 	if (offset < 0)
239 		return (-1);
240 
241 	if (strcmp(propname, "name") == 0) {
242 		/* Emulate the 'name' property */
243 		fdt_get_name(fdtp, offset, &len);
244 		return (len + 1);
245 	}
246 
247 	len = -1;
248 	prop = fdt_get_property(fdtp, offset, propname, &len);
249 
250 	return (len);
251 }
252 
253 /* Get the value of a property of a package. */
254 static ssize_t
255 ofw_fdt_getprop(ofw_t ofw, phandle_t package, const char *propname, void *buf,
256     size_t buflen)
257 {
258 	const void *prop;
259 	const char *name;
260 	int len, offset;
261 
262 	offset = fdt_phandle_offset(package);
263 	if (offset < 0)
264 		return (-1);
265 
266 	if (strcmp(propname, "name") == 0) {
267 		/* Emulate the 'name' property */
268 		name = fdt_get_name(fdtp, offset, &len);
269 		strncpy(buf, name, buflen);
270 		if (len + 1 > buflen)
271 			len = buflen;
272 		return (len + 1);
273 	}
274 
275 	prop = fdt_getprop(fdtp, offset, propname, &len);
276 	if (prop == NULL)
277 		return (-1);
278 
279 	if (len > buflen)
280 		len = buflen;
281 	bcopy(prop, buf, len);
282 	return (len);
283 }
284 
285 static int
286 fdt_nextprop(int offset, char *buf, size_t size)
287 {
288 	const struct fdt_property *prop;
289 	const char *name;
290 	uint32_t tag;
291 	int nextoffset, depth;
292 
293 	depth = 0;
294 	tag = fdt_next_tag(fdtp, offset, &nextoffset);
295 
296 	/* Find the next prop */
297 	do {
298 		offset = nextoffset;
299 		tag = fdt_next_tag(fdtp, offset, &nextoffset);
300 
301 		if (tag == FDT_BEGIN_NODE)
302 			depth++;
303 		else if (tag == FDT_END_NODE)
304 			depth--;
305 		else if ((tag == FDT_PROP) && (depth == 0)) {
306 			prop =
307 			    (const struct fdt_property *)fdt_offset_ptr(fdtp,
308 			    offset, sizeof(*prop));
309 			name = fdt_string(fdtp,
310 			    fdt32_to_cpu(prop->nameoff));
311 			strncpy(buf, name, size);
312 			return (strlen(name));
313 		} else
314 			depth = -1;
315 	} while (depth >= 0);
316 
317 	return (-1);
318 }
319 
320 /*
321  * Get the next property of a package. Return the actual len of retrieved
322  * prop name.
323  */
324 static int
325 ofw_fdt_nextprop(ofw_t ofw, phandle_t package, const char *previous, char *buf,
326     size_t size)
327 {
328 	const struct fdt_property *prop;
329 	int offset, rv;
330 
331 	offset = fdt_phandle_offset(package);
332 	if (offset < 0)
333 		return (-1);
334 
335 	if (previous == NULL)
336 		/* Find the first prop in the node */
337 		return (fdt_nextprop(offset, buf, size));
338 
339 	/*
340 	 * Advance to the previous prop
341 	 */
342 	prop = fdt_get_property(fdtp, offset, previous, NULL);
343 	if (prop == NULL)
344 		return (-1);
345 
346 	offset = fdt_phandle_offset((phandle_t)prop);
347 	rv = fdt_nextprop(offset, buf, size);
348 	return (rv);
349 }
350 
351 /* Set the value of a property of a package. */
352 static int
353 ofw_fdt_setprop(ofw_t ofw, phandle_t package, const char *propname,
354     const void *buf, size_t len)
355 {
356 	int offset;
357 
358 	offset = fdt_phandle_offset(package);
359 	if (offset < 0)
360 		return (-1);
361 
362 	return (fdt_setprop_inplace(fdtp, offset, propname, buf, len));
363 }
364 
365 /* Convert a device specifier to a fully qualified pathname. */
366 static ssize_t
367 ofw_fdt_canon(ofw_t ofw, const char *device, char *buf, size_t len)
368 {
369 
370 	return (-1);
371 }
372 
373 /* Return a package handle for the specified device. */
374 static phandle_t
375 ofw_fdt_finddevice(ofw_t ofw, const char *device)
376 {
377 	phandle_t p;
378 	int offset;
379 
380 	offset = fdt_path_offset(fdtp, device);
381 
382 	p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
383 
384 	return (p);
385 }
386 
387 /* Return the fully qualified pathname corresponding to an instance. */
388 static ssize_t
389 ofw_fdt_instance_to_path(ofw_t ofw, ihandle_t instance, char *buf, size_t len)
390 {
391 
392 	return (-1);
393 }
394 
395 /* Return the fully qualified pathname corresponding to a package. */
396 static ssize_t
397 ofw_fdt_package_to_path(ofw_t ofw, phandle_t package, char *buf, size_t len)
398 {
399 
400 	return (-1);
401 }
402 
403 static int
404 ofw_fdt_fixup(ofw_t ofw)
405 {
406 #define FDT_MODEL_LEN	80
407 	char model[FDT_MODEL_LEN];
408 	phandle_t root;
409 	ssize_t len;
410 	int i;
411 
412 	if ((root = ofw_fdt_finddevice(ofw, "/")) == 0)
413 		return (ENODEV);
414 
415 	if ((len = ofw_fdt_getproplen(ofw, root, "model")) <= 0)
416 		return (0);
417 
418 	bzero(model, FDT_MODEL_LEN);
419 	if (ofw_fdt_getprop(ofw, root, "model", model, FDT_MODEL_LEN) <= 0)
420 		return (0);
421 
422 	/*
423 	 * Search fixup table and call handler if appropriate.
424 	 */
425 	for (i = 0; fdt_fixup_table[i].model != NULL; i++) {
426 		if (strncmp(model, fdt_fixup_table[i].model,
427 		    FDT_MODEL_LEN) != 0)
428 			continue;
429 
430 		if (fdt_fixup_table[i].handler != NULL)
431 			(*fdt_fixup_table[i].handler)(root);
432 	}
433 
434 	return (0);
435 }
436 
437 static int
438 ofw_fdt_interpret(ofw_t ofw, const char *cmd, int nret, cell_t *retvals)
439 {
440 	int rv;
441 
442 	/*
443 	 * Note: FDT does not have the possibility to 'interpret' commands,
444 	 * but we abuse the interface a bit to use it for doing non-standard
445 	 * operations on the device tree blob.
446 	 *
447 	 * Currently the only supported 'command' is to trigger performing
448 	 * fixups.
449 	 */
450 	if (strncmp("perform-fixup", cmd, 13) != 0)
451 		return (0);
452 
453 	rv = ofw_fdt_fixup(ofw);
454 	if (nret > 0)
455 		retvals[0] = rv;
456 
457 	return (rv);
458 }
459