xref: /openbmc/u-boot/lib/fdtdec.c (revision e874d5b0)
1 /*
2  * Copyright (c) 2011 The Chromium OS Authors.
3  * See file CREDITS for list of people who contributed to this
4  * project.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation; either version 2 of
9  * the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
19  * MA 02111-1307 USA
20  */
21 
22 #include <common.h>
23 #include <serial.h>
24 #include <libfdt.h>
25 #include <fdtdec.h>
26 
27 #include <asm/gpio.h>
28 
29 DECLARE_GLOBAL_DATA_PTR;
30 
31 /*
32  * Here are the type we know about. One day we might allow drivers to
33  * register. For now we just put them here. The COMPAT macro allows us to
34  * turn this into a sparse list later, and keeps the ID with the name.
35  */
36 #define COMPAT(id, name) name
37 static const char * const compat_names[COMPAT_COUNT] = {
38 	COMPAT(UNKNOWN, "<none>"),
39 	COMPAT(NVIDIA_TEGRA20_USB, "nvidia,tegra20-ehci"),
40 	COMPAT(NVIDIA_TEGRA20_I2C, "nvidia,tegra20-i2c"),
41 	COMPAT(NVIDIA_TEGRA20_DVC, "nvidia,tegra20-i2c-dvc"),
42 	COMPAT(NVIDIA_TEGRA20_EMC, "nvidia,tegra20-emc"),
43 	COMPAT(NVIDIA_TEGRA20_EMC_TABLE, "nvidia,tegra20-emc-table"),
44 	COMPAT(NVIDIA_TEGRA20_KBC, "nvidia,tegra20-kbc"),
45 	COMPAT(NVIDIA_TEGRA20_NAND, "nvidia,tegra20-nand"),
46 	COMPAT(NVIDIA_TEGRA20_PWM, "nvidia,tegra20-pwm"),
47 	COMPAT(NVIDIA_TEGRA20_DC, "nvidia,tegra20-dc"),
48 	COMPAT(NVIDIA_TEGRA20_SFLASH, "nvidia,tegra20-sflash"),
49 	COMPAT(NVIDIA_TEGRA20_SLINK, "nvidia,tegra20-slink"),
50 	COMPAT(SMSC_LAN9215, "smsc,lan9215"),
51 	COMPAT(SAMSUNG_EXYNOS5_SROMC, "samsung,exynos-sromc"),
52 	COMPAT(SAMSUNG_S3C2440_I2C, "samsung,s3c2440-i2c"),
53 	COMPAT(SAMSUNG_EXYNOS5_SOUND, "samsung,exynos-sound"),
54 	COMPAT(WOLFSON_WM8994_CODEC, "wolfson,wm8994-codec"),
55 	COMPAT(SAMSUNG_EXYNOS_SPI, "samsung,exynos-spi"),
56 	COMPAT(SAMSUNG_EXYNOS_EHCI, "samsung,exynos-ehci"),
57 	COMPAT(SAMSUNG_EXYNOS_USB_PHY, "samsung,exynos-usb-phy"),
58 	COMPAT(MAXIM_MAX77686_PMIC, "maxim,max77686_pmic"),
59 };
60 
61 const char *fdtdec_get_compatible(enum fdt_compat_id id)
62 {
63 	/* We allow reading of the 'unknown' ID for testing purposes */
64 	assert(id >= 0 && id < COMPAT_COUNT);
65 	return compat_names[id];
66 }
67 
68 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
69 		const char *prop_name)
70 {
71 	const fdt_addr_t *cell;
72 	int len;
73 
74 	debug("%s: %s: ", __func__, prop_name);
75 	cell = fdt_getprop(blob, node, prop_name, &len);
76 	if (cell && (len == sizeof(fdt_addr_t) ||
77 			len == sizeof(fdt_addr_t) * 2)) {
78 		fdt_addr_t addr = fdt_addr_to_cpu(*cell);
79 
80 		debug("%p\n", (void *)addr);
81 		return addr;
82 	}
83 	debug("(not found)\n");
84 	return FDT_ADDR_T_NONE;
85 }
86 
87 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
88 		s32 default_val)
89 {
90 	const s32 *cell;
91 	int len;
92 
93 	debug("%s: %s: ", __func__, prop_name);
94 	cell = fdt_getprop(blob, node, prop_name, &len);
95 	if (cell && len >= sizeof(s32)) {
96 		s32 val = fdt32_to_cpu(cell[0]);
97 
98 		debug("%#x (%d)\n", val, val);
99 		return val;
100 	}
101 	debug("(not found)\n");
102 	return default_val;
103 }
104 
105 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
106 		uint64_t default_val)
107 {
108 	const uint64_t *cell64;
109 	int length;
110 
111 	cell64 = fdt_getprop(blob, node, prop_name, &length);
112 	if (!cell64 || length < sizeof(*cell64))
113 		return default_val;
114 
115 	return fdt64_to_cpu(*cell64);
116 }
117 
118 int fdtdec_get_is_enabled(const void *blob, int node)
119 {
120 	const char *cell;
121 
122 	/*
123 	 * It should say "okay", so only allow that. Some fdts use "ok" but
124 	 * this is a bug. Please fix your device tree source file. See here
125 	 * for discussion:
126 	 *
127 	 * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html
128 	 */
129 	cell = fdt_getprop(blob, node, "status", NULL);
130 	if (cell)
131 		return 0 == strcmp(cell, "okay");
132 	return 1;
133 }
134 
135 enum fdt_compat_id fdtdec_lookup(const void *blob, int node)
136 {
137 	enum fdt_compat_id id;
138 
139 	/* Search our drivers */
140 	for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
141 		if (0 == fdt_node_check_compatible(blob, node,
142 				compat_names[id]))
143 			return id;
144 	return COMPAT_UNKNOWN;
145 }
146 
147 int fdtdec_next_compatible(const void *blob, int node,
148 		enum fdt_compat_id id)
149 {
150 	return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
151 }
152 
153 int fdtdec_next_compatible_subnode(const void *blob, int node,
154 		enum fdt_compat_id id, int *depthp)
155 {
156 	do {
157 		node = fdt_next_node(blob, node, depthp);
158 	} while (*depthp > 1);
159 
160 	/* If this is a direct subnode, and compatible, return it */
161 	if (*depthp == 1 && 0 == fdt_node_check_compatible(
162 						blob, node, compat_names[id]))
163 		return node;
164 
165 	return -FDT_ERR_NOTFOUND;
166 }
167 
168 int fdtdec_next_alias(const void *blob, const char *name,
169 		enum fdt_compat_id id, int *upto)
170 {
171 #define MAX_STR_LEN 20
172 	char str[MAX_STR_LEN + 20];
173 	int node, err;
174 
175 	/* snprintf() is not available */
176 	assert(strlen(name) < MAX_STR_LEN);
177 	sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto);
178 	node = fdt_path_offset(blob, str);
179 	if (node < 0)
180 		return node;
181 	err = fdt_node_check_compatible(blob, node, compat_names[id]);
182 	if (err < 0)
183 		return err;
184 	if (err)
185 		return -FDT_ERR_NOTFOUND;
186 	(*upto)++;
187 	return node;
188 }
189 
190 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
191 			enum fdt_compat_id id, int *node_list, int maxcount)
192 {
193 	memset(node_list, '\0', sizeof(*node_list) * maxcount);
194 
195 	return fdtdec_add_aliases_for_id(blob, name, id, node_list, maxcount);
196 }
197 
198 /* TODO: Can we tighten this code up a little? */
199 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
200 			enum fdt_compat_id id, int *node_list, int maxcount)
201 {
202 	int name_len = strlen(name);
203 	int nodes[maxcount];
204 	int num_found = 0;
205 	int offset, node;
206 	int alias_node;
207 	int count;
208 	int i, j;
209 
210 	/* find the alias node if present */
211 	alias_node = fdt_path_offset(blob, "/aliases");
212 
213 	/*
214 	 * start with nothing, and we can assume that the root node can't
215 	 * match
216 	 */
217 	memset(nodes, '\0', sizeof(nodes));
218 
219 	/* First find all the compatible nodes */
220 	for (node = count = 0; node >= 0 && count < maxcount;) {
221 		node = fdtdec_next_compatible(blob, node, id);
222 		if (node >= 0)
223 			nodes[count++] = node;
224 	}
225 	if (node >= 0)
226 		debug("%s: warning: maxcount exceeded with alias '%s'\n",
227 		       __func__, name);
228 
229 	/* Now find all the aliases */
230 	for (offset = fdt_first_property_offset(blob, alias_node);
231 			offset > 0;
232 			offset = fdt_next_property_offset(blob, offset)) {
233 		const struct fdt_property *prop;
234 		const char *path;
235 		int number;
236 		int found;
237 
238 		node = 0;
239 		prop = fdt_get_property_by_offset(blob, offset, NULL);
240 		path = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
241 		if (prop->len && 0 == strncmp(path, name, name_len))
242 			node = fdt_path_offset(blob, prop->data);
243 		if (node <= 0)
244 			continue;
245 
246 		/* Get the alias number */
247 		number = simple_strtoul(path + name_len, NULL, 10);
248 		if (number < 0 || number >= maxcount) {
249 			debug("%s: warning: alias '%s' is out of range\n",
250 			       __func__, path);
251 			continue;
252 		}
253 
254 		/* Make sure the node we found is actually in our list! */
255 		found = -1;
256 		for (j = 0; j < count; j++)
257 			if (nodes[j] == node) {
258 				found = j;
259 				break;
260 			}
261 
262 		if (found == -1) {
263 			debug("%s: warning: alias '%s' points to a node "
264 				"'%s' that is missing or is not compatible "
265 				" with '%s'\n", __func__, path,
266 				fdt_get_name(blob, node, NULL),
267 			       compat_names[id]);
268 			continue;
269 		}
270 
271 		/*
272 		 * Add this node to our list in the right place, and mark
273 		 * it as done.
274 		 */
275 		if (fdtdec_get_is_enabled(blob, node)) {
276 			if (node_list[number]) {
277 				debug("%s: warning: alias '%s' requires that "
278 				      "a node be placed in the list in a "
279 				      "position which is already filled by "
280 				      "node '%s'\n", __func__, path,
281 				      fdt_get_name(blob, node, NULL));
282 				continue;
283 			}
284 			node_list[number] = node;
285 			if (number >= num_found)
286 				num_found = number + 1;
287 		}
288 		nodes[found] = 0;
289 	}
290 
291 	/* Add any nodes not mentioned by an alias */
292 	for (i = j = 0; i < maxcount; i++) {
293 		if (!node_list[i]) {
294 			for (; j < maxcount; j++)
295 				if (nodes[j] &&
296 					fdtdec_get_is_enabled(blob, nodes[j]))
297 					break;
298 
299 			/* Have we run out of nodes to add? */
300 			if (j == maxcount)
301 				break;
302 
303 			assert(!node_list[i]);
304 			node_list[i] = nodes[j++];
305 			if (i >= num_found)
306 				num_found = i + 1;
307 		}
308 	}
309 
310 	return num_found;
311 }
312 
313 int fdtdec_check_fdt(void)
314 {
315 	/*
316 	 * We must have an FDT, but we cannot panic() yet since the console
317 	 * is not ready. So for now, just assert(). Boards which need an early
318 	 * FDT (prior to console ready) will need to make their own
319 	 * arrangements and do their own checks.
320 	 */
321 	assert(!fdtdec_prepare_fdt());
322 	return 0;
323 }
324 
325 /*
326  * This function is a little odd in that it accesses global data. At some
327  * point if the architecture board.c files merge this will make more sense.
328  * Even now, it is common code.
329  */
330 int fdtdec_prepare_fdt(void)
331 {
332 	if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob)) {
333 		printf("No valid FDT found - please append one to U-Boot "
334 			"binary, use u-boot-dtb.bin or define "
335 			"CONFIG_OF_EMBED\n");
336 		return -1;
337 	}
338 	return 0;
339 }
340 
341 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
342 {
343 	const u32 *phandle;
344 	int lookup;
345 
346 	debug("%s: %s\n", __func__, prop_name);
347 	phandle = fdt_getprop(blob, node, prop_name, NULL);
348 	if (!phandle)
349 		return -FDT_ERR_NOTFOUND;
350 
351 	lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
352 	return lookup;
353 }
354 
355 /**
356  * Look up a property in a node and check that it has a minimum length.
357  *
358  * @param blob		FDT blob
359  * @param node		node to examine
360  * @param prop_name	name of property to find
361  * @param min_len	minimum property length in bytes
362  * @param err		0 if ok, or -FDT_ERR_NOTFOUND if the property is not
363 			found, or -FDT_ERR_BADLAYOUT if not enough data
364  * @return pointer to cell, which is only valid if err == 0
365  */
366 static const void *get_prop_check_min_len(const void *blob, int node,
367 		const char *prop_name, int min_len, int *err)
368 {
369 	const void *cell;
370 	int len;
371 
372 	debug("%s: %s\n", __func__, prop_name);
373 	cell = fdt_getprop(blob, node, prop_name, &len);
374 	if (!cell)
375 		*err = -FDT_ERR_NOTFOUND;
376 	else if (len < min_len)
377 		*err = -FDT_ERR_BADLAYOUT;
378 	else
379 		*err = 0;
380 	return cell;
381 }
382 
383 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
384 		u32 *array, int count)
385 {
386 	const u32 *cell;
387 	int i, err = 0;
388 
389 	debug("%s: %s\n", __func__, prop_name);
390 	cell = get_prop_check_min_len(blob, node, prop_name,
391 				      sizeof(u32) * count, &err);
392 	if (!err) {
393 		for (i = 0; i < count; i++)
394 			array[i] = fdt32_to_cpu(cell[i]);
395 	}
396 	return err;
397 }
398 
399 const u32 *fdtdec_locate_array(const void *blob, int node,
400 			       const char *prop_name, int count)
401 {
402 	const u32 *cell;
403 	int err;
404 
405 	cell = get_prop_check_min_len(blob, node, prop_name,
406 				      sizeof(u32) * count, &err);
407 	return err ? NULL : cell;
408 }
409 
410 int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
411 {
412 	const s32 *cell;
413 	int len;
414 
415 	debug("%s: %s\n", __func__, prop_name);
416 	cell = fdt_getprop(blob, node, prop_name, &len);
417 	return cell != NULL;
418 }
419 
420 /**
421  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
422  * terminating item.
423  *
424  * @param blob		FDT blob to use
425  * @param node		Node to look at
426  * @param prop_name	Node property name
427  * @param gpio		Array of gpio elements to fill from FDT. This will be
428  *			untouched if either 0 or an error is returned
429  * @param max_count	Maximum number of elements allowed
430  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
431  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
432  */
433 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
434 		struct fdt_gpio_state *gpio, int max_count)
435 {
436 	const struct fdt_property *prop;
437 	const u32 *cell;
438 	const char *name;
439 	int len, i;
440 
441 	debug("%s: %s\n", __func__, prop_name);
442 	assert(max_count > 0);
443 	prop = fdt_get_property(blob, node, prop_name, &len);
444 	if (!prop) {
445 		debug("%s: property '%s' missing\n", __func__, prop_name);
446 		return -FDT_ERR_NOTFOUND;
447 	}
448 
449 	/* We will use the name to tag the GPIO */
450 	name = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
451 	cell = (u32 *)prop->data;
452 	len /= sizeof(u32) * 3;		/* 3 cells per GPIO record */
453 	if (len > max_count) {
454 		debug(" %s: too many GPIOs / cells for "
455 			"property '%s'\n", __func__, prop_name);
456 		return -FDT_ERR_BADLAYOUT;
457 	}
458 
459 	/* Read out the GPIO data from the cells */
460 	for (i = 0; i < len; i++, cell += 3) {
461 		gpio[i].gpio = fdt32_to_cpu(cell[1]);
462 		gpio[i].flags = fdt32_to_cpu(cell[2]);
463 		gpio[i].name = name;
464 	}
465 
466 	return len;
467 }
468 
469 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
470 		struct fdt_gpio_state *gpio)
471 {
472 	int err;
473 
474 	debug("%s: %s\n", __func__, prop_name);
475 	gpio->gpio = FDT_GPIO_NONE;
476 	gpio->name = NULL;
477 	err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1);
478 	return err == 1 ? 0 : err;
479 }
480 
481 int fdtdec_get_gpio(struct fdt_gpio_state *gpio)
482 {
483 	int val;
484 
485 	if (!fdt_gpio_isvalid(gpio))
486 		return -1;
487 
488 	val = gpio_get_value(gpio->gpio);
489 	return gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
490 }
491 
492 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val)
493 {
494 	if (!fdt_gpio_isvalid(gpio))
495 		return -1;
496 
497 	val = gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
498 	return gpio_set_value(gpio->gpio, val);
499 }
500 
501 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio)
502 {
503 	/*
504 	 * Return success if there is no GPIO defined. This is used for
505 	 * optional GPIOs)
506 	 */
507 	if (!fdt_gpio_isvalid(gpio))
508 		return 0;
509 
510 	if (gpio_request(gpio->gpio, gpio->name))
511 		return -1;
512 	return 0;
513 }
514 
515 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
516 		u8 *array, int count)
517 {
518 	const u8 *cell;
519 	int err;
520 
521 	cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
522 	if (!err)
523 		memcpy(array, cell, count);
524 	return err;
525 }
526 
527 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
528 			     const char *prop_name, int count)
529 {
530 	const u8 *cell;
531 	int err;
532 
533 	cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
534 	if (err)
535 		return NULL;
536 	return cell;
537 }
538 
539 int fdtdec_get_config_int(const void *blob, const char *prop_name,
540 		int default_val)
541 {
542 	int config_node;
543 
544 	debug("%s: %s\n", __func__, prop_name);
545 	config_node = fdt_path_offset(blob, "/config");
546 	if (config_node < 0)
547 		return default_val;
548 	return fdtdec_get_int(blob, config_node, prop_name, default_val);
549 }
550 
551 int fdtdec_get_config_bool(const void *blob, const char *prop_name)
552 {
553 	int config_node;
554 	const void *prop;
555 
556 	debug("%s: %s\n", __func__, prop_name);
557 	config_node = fdt_path_offset(blob, "/config");
558 	if (config_node < 0)
559 		return 0;
560 	prop = fdt_get_property(blob, config_node, prop_name, NULL);
561 
562 	return prop != NULL;
563 }
564 
565 char *fdtdec_get_config_string(const void *blob, const char *prop_name)
566 {
567 	const char *nodep;
568 	int nodeoffset;
569 	int len;
570 
571 	debug("%s: %s\n", __func__, prop_name);
572 	nodeoffset = fdt_path_offset(blob, "/config");
573 	if (nodeoffset < 0)
574 		return NULL;
575 
576 	nodep = fdt_getprop(blob, nodeoffset, prop_name, &len);
577 	if (!nodep)
578 		return NULL;
579 
580 	return (char *)nodep;
581 }
582 
583 int fdtdec_decode_region(const void *blob, int node,
584 		const char *prop_name, void **ptrp, size_t *size)
585 {
586 	const fdt_addr_t *cell;
587 	int len;
588 
589 	debug("%s: %s\n", __func__, prop_name);
590 	cell = fdt_getprop(blob, node, prop_name, &len);
591 	if (!cell || (len != sizeof(fdt_addr_t) * 2))
592 		return -1;
593 
594 	*ptrp = (void *)fdt_addr_to_cpu(*cell);
595 	*size = fdt_size_to_cpu(cell[1]);
596 	debug("%s: size=%zx\n", __func__, *size);
597 	return 0;
598 }
599