ofw_fdt.c revision 257747 
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: head/sys/dev/ofw/ofw_fdt.c 257747 2013-11-06 14:38:53Z nwhitehorn $");
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
55static int ofw_fdt_init(ofw_t, void *);
56static phandle_t ofw_fdt_peer(ofw_t, phandle_t);
57static phandle_t ofw_fdt_child(ofw_t, phandle_t);
58static phandle_t ofw_fdt_parent(ofw_t, phandle_t);
59static phandle_t ofw_fdt_instance_to_package(ofw_t, ihandle_t);
60static ssize_t ofw_fdt_getproplen(ofw_t, phandle_t, const char *);
61static ssize_t ofw_fdt_getprop(ofw_t, phandle_t, const char *, void *, size_t);
62static int ofw_fdt_nextprop(ofw_t, phandle_t, const char *, char *, size_t);
63static int ofw_fdt_setprop(ofw_t, phandle_t, const char *, const void *,
64    size_t);
65static ssize_t ofw_fdt_canon(ofw_t, const char *, char *, size_t);
66static phandle_t ofw_fdt_finddevice(ofw_t, const char *);
67static ssize_t ofw_fdt_instance_to_path(ofw_t, ihandle_t, char *, size_t);
68static ssize_t ofw_fdt_package_to_path(ofw_t, phandle_t, char *, size_t);
69static int ofw_fdt_interpret(ofw_t, const char *, int, cell_t *);
70
71static 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
89static ofw_def_t ofw_fdt = {
90	OFW_FDT,
91	ofw_fdt_methods,
92	0
93};
94OFW_DEF(ofw_fdt);
95
96static void *fdtp = NULL;
97
98static int
99ofw_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
121static phandle_t
122fdt_offset_phandle(int offset)
123{
124	if (offset < 0)
125		return (0);
126	return ((phandle_t)offset + fdt_off_dt_struct(fdtp));
127}
128
129static int
130fdt_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. */
141static phandle_t
142ofw_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. */
170static phandle_t
171ofw_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. */
192static phandle_t
193ofw_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. */
206static phandle_t
207ofw_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. */
214static ssize_t
215ofw_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. */
237static ssize_t
238ofw_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 */
272static int
273ofw_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. */
316static int
317ofw_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. */
330static ssize_t
331ofw_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. */
338static phandle_t
339ofw_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. */
350static ssize_t
351ofw_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. */
358static ssize_t
359ofw_fdt_package_to_path(ofw_t ofw, phandle_t package, char *buf, size_t len)
360{
361
362	return (-1);
363}
364
365static int
366ofw_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
399static int
400ofw_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