xref: /freebsd/sys/dev/ofw/ofw_fdt.c (revision 1c6d60de932c8553af44629218cb9697bc0f2ef1)
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 /* Return the next sibling of this node or 0. */
141 static phandle_t
142 ofw_fdt_peer(ofw_t ofw, phandle_t node)
143 {
144 	int depth, offset;
145 
146 	if (node == 0) {
147 		/* Find root node */
148 		offset = fdt_path_offset(fdtp, "/");
149 
150 		return (fdt_offset_phandle(offset));
151 	}
152 
153 	offset = fdt_phandle_offset(node);
154 	if (offset < 0)
155 		return (0);
156 
157 	for (depth = 1, offset = fdt_next_node(fdtp, offset, &depth);
158 	    offset >= 0;
159 	    offset = fdt_next_node(fdtp, offset, &depth)) {
160 		if (depth < 0)
161 			return (0);
162 		if (depth == 1)
163 			return (fdt_offset_phandle(offset));
164 	}
165 
166 	return (0);
167 }
168 
169 /* Return the first child of this node or 0. */
170 static phandle_t
171 ofw_fdt_child(ofw_t ofw, phandle_t node)
172 {
173 	int depth, offset;
174 
175 	offset = fdt_phandle_offset(node);
176 	if (offset < 0)
177 		return (0);
178 
179 	for (depth = 0, offset = fdt_next_node(fdtp, offset, &depth);
180 	    (offset >= 0) && (depth > 0);
181 	    offset = fdt_next_node(fdtp, offset, &depth)) {
182 		if (depth < 0)
183 			return (0);
184 		if (depth == 1)
185 			return (fdt_offset_phandle(offset));
186 	}
187 
188 	return (0);
189 }
190 
191 /* Return the parent of this node or 0. */
192 static phandle_t
193 ofw_fdt_parent(ofw_t ofw, phandle_t node)
194 {
195 	int offset, paroffset;
196 
197 	offset = fdt_phandle_offset(node);
198 	if (offset < 0)
199 		return (0);
200 
201 	paroffset = fdt_parent_offset(fdtp, offset);
202 	return (fdt_offset_phandle(paroffset));
203 }
204 
205 /* Return the package handle that corresponds to an instance handle. */
206 static phandle_t
207 ofw_fdt_instance_to_package(ofw_t ofw, ihandle_t instance)
208 {
209 
210 	return (-1);
211 }
212 
213 /* Get the length of a property of a package. */
214 static ssize_t
215 ofw_fdt_getproplen(ofw_t ofw, phandle_t package, const char *propname)
216 {
217 	const struct fdt_property *prop;
218 	int offset, len;
219 
220 	offset = fdt_phandle_offset(package);
221 	if (offset < 0)
222 		return (-1);
223 
224 	if (strcmp(propname, "name") == 0) {
225 		/* Emulate the 'name' property */
226 		fdt_get_name(fdtp, offset, &len);
227 		return (len + 1);
228 	}
229 
230 	len = -1;
231 	prop = fdt_get_property(fdtp, offset, propname, &len);
232 
233 	return (len);
234 }
235 
236 /* Get the value of a property of a package. */
237 static ssize_t
238 ofw_fdt_getprop(ofw_t ofw, phandle_t package, const char *propname, void *buf,
239     size_t buflen)
240 {
241 	const void *prop;
242 	const char *name;
243 	int len, offset;
244 
245 	offset = fdt_phandle_offset(package);
246 	if (offset < 0)
247 		return (-1);
248 
249 	if (strcmp(propname, "name") == 0) {
250 		/* Emulate the 'name' property */
251 		name = fdt_get_name(fdtp, offset, &len);
252 		strncpy(buf, name, buflen);
253 		if (len + 1 > buflen)
254 			len = buflen;
255 		return (len + 1);
256 	}
257 
258 	prop = fdt_getprop(fdtp, offset, propname, &len);
259 	if (prop == NULL)
260 		return (-1);
261 
262 	if (len > buflen)
263 		len = buflen;
264 	bcopy(prop, buf, len);
265 	return (len);
266 }
267 
268 /*
269  * Get the next property of a package. Return the actual len of retrieved
270  * prop name.
271  */
272 static int
273 ofw_fdt_nextprop(ofw_t ofw, phandle_t package, const char *previous, char *buf,
274     size_t size)
275 {
276 	const struct fdt_property *prop;
277 	const char *name;
278 	int offset;
279 
280 	offset = fdt_phandle_offset(package);
281 	if (offset < 0)
282 		return (-1);
283 
284 	/* Find the first prop in the node */
285 	offset = fdt_first_property_offset(fdtp, offset);
286 	if (offset < 0)
287 		return (0); /* No properties */
288 
289 	if (previous != NULL) {
290 		while (offset >= 0) {
291 			prop = fdt_get_property_by_offset(fdtp, offset, NULL);
292 			if (prop == NULL)
293 				return (-1); /* Internal error */
294 
295 			offset = fdt_next_property_offset(fdtp, offset);
296 			if (offset < 0)
297 				return (0); /* No more properties */
298 
299 			/* Check if the last one was the one we wanted */
300 			name = fdt_string(fdtp, fdt32_to_cpu(prop->nameoff));
301 			if (strcmp(name, previous) == 0)
302 				break;
303 		}
304 	}
305 
306 	prop = fdt_get_property_by_offset(fdtp, offset, &offset);
307 	if (prop == NULL)
308 		return (-1); /* Internal error */
309 
310 	strncpy(buf, fdt_string(fdtp, fdt32_to_cpu(prop->nameoff)), size);
311 
312 	return (strlen(buf));
313 }
314 
315 /* Set the value of a property of a package. */
316 static int
317 ofw_fdt_setprop(ofw_t ofw, phandle_t package, const char *propname,
318     const void *buf, size_t len)
319 {
320 	int offset;
321 
322 	offset = fdt_phandle_offset(package);
323 	if (offset < 0)
324 		return (-1);
325 
326 	return (fdt_setprop_inplace(fdtp, offset, propname, buf, len));
327 }
328 
329 /* Convert a device specifier to a fully qualified pathname. */
330 static ssize_t
331 ofw_fdt_canon(ofw_t ofw, const char *device, char *buf, size_t len)
332 {
333 
334 	return (-1);
335 }
336 
337 /* Return a package handle for the specified device. */
338 static phandle_t
339 ofw_fdt_finddevice(ofw_t ofw, const char *device)
340 {
341 	int offset;
342 
343 	offset = fdt_path_offset(fdtp, device);
344 	if (offset < 0)
345 		return (-1);
346 	return (fdt_offset_phandle(offset));
347 }
348 
349 /* Return the fully qualified pathname corresponding to an instance. */
350 static ssize_t
351 ofw_fdt_instance_to_path(ofw_t ofw, ihandle_t instance, char *buf, size_t len)
352 {
353 
354 	return (-1);
355 }
356 
357 /* Return the fully qualified pathname corresponding to a package. */
358 static ssize_t
359 ofw_fdt_package_to_path(ofw_t ofw, phandle_t package, char *buf, size_t len)
360 {
361 
362 	return (-1);
363 }
364 
365 static int
366 ofw_fdt_fixup(ofw_t ofw)
367 {
368 #define FDT_MODEL_LEN	80
369 	char model[FDT_MODEL_LEN];
370 	phandle_t root;
371 	ssize_t len;
372 	int i;
373 
374 	if ((root = ofw_fdt_finddevice(ofw, "/")) == -1)
375 		return (ENODEV);
376 
377 	if ((len = ofw_fdt_getproplen(ofw, root, "model")) <= 0)
378 		return (0);
379 
380 	bzero(model, FDT_MODEL_LEN);
381 	if (ofw_fdt_getprop(ofw, root, "model", model, FDT_MODEL_LEN) <= 0)
382 		return (0);
383 
384 	/*
385 	 * Search fixup table and call handler if appropriate.
386 	 */
387 	for (i = 0; fdt_fixup_table[i].model != NULL; i++) {
388 		if (strncmp(model, fdt_fixup_table[i].model,
389 		    FDT_MODEL_LEN) != 0)
390 			continue;
391 
392 		if (fdt_fixup_table[i].handler != NULL)
393 			(*fdt_fixup_table[i].handler)(root);
394 	}
395 
396 	return (0);
397 }
398 
399 static int
400 ofw_fdt_interpret(ofw_t ofw, const char *cmd, int nret, cell_t *retvals)
401 {
402 	int rv;
403 
404 	/*
405 	 * Note: FDT does not have the possibility to 'interpret' commands,
406 	 * but we abuse the interface a bit to use it for doing non-standard
407 	 * operations on the device tree blob.
408 	 *
409 	 * Currently the only supported 'command' is to trigger performing
410 	 * fixups.
411 	 */
412 	if (strncmp("perform-fixup", cmd, 13) != 0)
413 		return (0);
414 
415 	rv = ofw_fdt_fixup(ofw);
416 	if (nret > 0)
417 		retvals[0] = rv;
418 
419 	return (rv);
420 }
421