xref: /openbmc/u-boot/lib/fdtdec.c (revision 2c1af9dcdcf4ede8d153c0918beca9067ec0eb36)
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_TEGRA114_I2C, "nvidia,tegra114-i2c"),
41 	COMPAT(NVIDIA_TEGRA20_I2C, "nvidia,tegra20-i2c"),
42 	COMPAT(NVIDIA_TEGRA20_DVC, "nvidia,tegra20-i2c-dvc"),
43 	COMPAT(NVIDIA_TEGRA20_EMC, "nvidia,tegra20-emc"),
44 	COMPAT(NVIDIA_TEGRA20_EMC_TABLE, "nvidia,tegra20-emc-table"),
45 	COMPAT(NVIDIA_TEGRA20_KBC, "nvidia,tegra20-kbc"),
46 	COMPAT(NVIDIA_TEGRA20_NAND, "nvidia,tegra20-nand"),
47 	COMPAT(NVIDIA_TEGRA20_PWM, "nvidia,tegra20-pwm"),
48 	COMPAT(NVIDIA_TEGRA20_DC, "nvidia,tegra20-dc"),
49 	COMPAT(NVIDIA_TEGRA30_SDMMC, "nvidia,tegra30-sdhci"),
50 	COMPAT(NVIDIA_TEGRA20_SDMMC, "nvidia,tegra20-sdhci"),
51 	COMPAT(NVIDIA_TEGRA20_SFLASH, "nvidia,tegra20-sflash"),
52 	COMPAT(NVIDIA_TEGRA20_SLINK, "nvidia,tegra20-slink"),
53 	COMPAT(SMSC_LAN9215, "smsc,lan9215"),
54 	COMPAT(SAMSUNG_EXYNOS5_SROMC, "samsung,exynos-sromc"),
55 	COMPAT(SAMSUNG_S3C2440_I2C, "samsung,s3c2440-i2c"),
56 	COMPAT(SAMSUNG_EXYNOS5_SOUND, "samsung,exynos-sound"),
57 	COMPAT(WOLFSON_WM8994_CODEC, "wolfson,wm8994-codec"),
58 	COMPAT(SAMSUNG_EXYNOS_SPI, "samsung,exynos-spi"),
59 	COMPAT(SAMSUNG_EXYNOS_EHCI, "samsung,exynos-ehci"),
60 	COMPAT(SAMSUNG_EXYNOS_USB_PHY, "samsung,exynos-usb-phy"),
61 	COMPAT(MAXIM_MAX77686_PMIC, "maxim,max77686_pmic"),
62 };
63 
64 const char *fdtdec_get_compatible(enum fdt_compat_id id)
65 {
66 	/* We allow reading of the 'unknown' ID for testing purposes */
67 	assert(id >= 0 && id < COMPAT_COUNT);
68 	return compat_names[id];
69 }
70 
71 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
72 		const char *prop_name)
73 {
74 	const fdt_addr_t *cell;
75 	int len;
76 
77 	debug("%s: %s: ", __func__, prop_name);
78 	cell = fdt_getprop(blob, node, prop_name, &len);
79 	if (cell && (len == sizeof(fdt_addr_t) ||
80 			len == sizeof(fdt_addr_t) * 2)) {
81 		fdt_addr_t addr = fdt_addr_to_cpu(*cell);
82 
83 		debug("%p\n", (void *)addr);
84 		return addr;
85 	}
86 	debug("(not found)\n");
87 	return FDT_ADDR_T_NONE;
88 }
89 
90 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
91 		s32 default_val)
92 {
93 	const s32 *cell;
94 	int len;
95 
96 	debug("%s: %s: ", __func__, prop_name);
97 	cell = fdt_getprop(blob, node, prop_name, &len);
98 	if (cell && len >= sizeof(s32)) {
99 		s32 val = fdt32_to_cpu(cell[0]);
100 
101 		debug("%#x (%d)\n", val, val);
102 		return val;
103 	}
104 	debug("(not found)\n");
105 	return default_val;
106 }
107 
108 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
109 		uint64_t default_val)
110 {
111 	const uint64_t *cell64;
112 	int length;
113 
114 	cell64 = fdt_getprop(blob, node, prop_name, &length);
115 	if (!cell64 || length < sizeof(*cell64))
116 		return default_val;
117 
118 	return fdt64_to_cpu(*cell64);
119 }
120 
121 int fdtdec_get_is_enabled(const void *blob, int node)
122 {
123 	const char *cell;
124 
125 	/*
126 	 * It should say "okay", so only allow that. Some fdts use "ok" but
127 	 * this is a bug. Please fix your device tree source file. See here
128 	 * for discussion:
129 	 *
130 	 * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html
131 	 */
132 	cell = fdt_getprop(blob, node, "status", NULL);
133 	if (cell)
134 		return 0 == strcmp(cell, "okay");
135 	return 1;
136 }
137 
138 enum fdt_compat_id fdtdec_lookup(const void *blob, int node)
139 {
140 	enum fdt_compat_id id;
141 
142 	/* Search our drivers */
143 	for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
144 		if (0 == fdt_node_check_compatible(blob, node,
145 				compat_names[id]))
146 			return id;
147 	return COMPAT_UNKNOWN;
148 }
149 
150 int fdtdec_next_compatible(const void *blob, int node,
151 		enum fdt_compat_id id)
152 {
153 	return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
154 }
155 
156 int fdtdec_next_compatible_subnode(const void *blob, int node,
157 		enum fdt_compat_id id, int *depthp)
158 {
159 	do {
160 		node = fdt_next_node(blob, node, depthp);
161 	} while (*depthp > 1);
162 
163 	/* If this is a direct subnode, and compatible, return it */
164 	if (*depthp == 1 && 0 == fdt_node_check_compatible(
165 						blob, node, compat_names[id]))
166 		return node;
167 
168 	return -FDT_ERR_NOTFOUND;
169 }
170 
171 int fdtdec_next_alias(const void *blob, const char *name,
172 		enum fdt_compat_id id, int *upto)
173 {
174 #define MAX_STR_LEN 20
175 	char str[MAX_STR_LEN + 20];
176 	int node, err;
177 
178 	/* snprintf() is not available */
179 	assert(strlen(name) < MAX_STR_LEN);
180 	sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto);
181 	node = fdt_path_offset(blob, str);
182 	if (node < 0)
183 		return node;
184 	err = fdt_node_check_compatible(blob, node, compat_names[id]);
185 	if (err < 0)
186 		return err;
187 	if (err)
188 		return -FDT_ERR_NOTFOUND;
189 	(*upto)++;
190 	return node;
191 }
192 
193 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
194 			enum fdt_compat_id id, int *node_list, int maxcount)
195 {
196 	memset(node_list, '\0', sizeof(*node_list) * maxcount);
197 
198 	return fdtdec_add_aliases_for_id(blob, name, id, node_list, maxcount);
199 }
200 
201 /* TODO: Can we tighten this code up a little? */
202 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
203 			enum fdt_compat_id id, int *node_list, int maxcount)
204 {
205 	int name_len = strlen(name);
206 	int nodes[maxcount];
207 	int num_found = 0;
208 	int offset, node;
209 	int alias_node;
210 	int count;
211 	int i, j;
212 
213 	/* find the alias node if present */
214 	alias_node = fdt_path_offset(blob, "/aliases");
215 
216 	/*
217 	 * start with nothing, and we can assume that the root node can't
218 	 * match
219 	 */
220 	memset(nodes, '\0', sizeof(nodes));
221 
222 	/* First find all the compatible nodes */
223 	for (node = count = 0; node >= 0 && count < maxcount;) {
224 		node = fdtdec_next_compatible(blob, node, id);
225 		if (node >= 0)
226 			nodes[count++] = node;
227 	}
228 	if (node >= 0)
229 		debug("%s: warning: maxcount exceeded with alias '%s'\n",
230 		       __func__, name);
231 
232 	/* Now find all the aliases */
233 	for (offset = fdt_first_property_offset(blob, alias_node);
234 			offset > 0;
235 			offset = fdt_next_property_offset(blob, offset)) {
236 		const struct fdt_property *prop;
237 		const char *path;
238 		int number;
239 		int found;
240 
241 		node = 0;
242 		prop = fdt_get_property_by_offset(blob, offset, NULL);
243 		path = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
244 		if (prop->len && 0 == strncmp(path, name, name_len))
245 			node = fdt_path_offset(blob, prop->data);
246 		if (node <= 0)
247 			continue;
248 
249 		/* Get the alias number */
250 		number = simple_strtoul(path + name_len, NULL, 10);
251 		if (number < 0 || number >= maxcount) {
252 			debug("%s: warning: alias '%s' is out of range\n",
253 			       __func__, path);
254 			continue;
255 		}
256 
257 		/* Make sure the node we found is actually in our list! */
258 		found = -1;
259 		for (j = 0; j < count; j++)
260 			if (nodes[j] == node) {
261 				found = j;
262 				break;
263 			}
264 
265 		if (found == -1) {
266 			debug("%s: warning: alias '%s' points to a node "
267 				"'%s' that is missing or is not compatible "
268 				" with '%s'\n", __func__, path,
269 				fdt_get_name(blob, node, NULL),
270 			       compat_names[id]);
271 			continue;
272 		}
273 
274 		/*
275 		 * Add this node to our list in the right place, and mark
276 		 * it as done.
277 		 */
278 		if (fdtdec_get_is_enabled(blob, node)) {
279 			if (node_list[number]) {
280 				debug("%s: warning: alias '%s' requires that "
281 				      "a node be placed in the list in a "
282 				      "position which is already filled by "
283 				      "node '%s'\n", __func__, path,
284 				      fdt_get_name(blob, node, NULL));
285 				continue;
286 			}
287 			node_list[number] = node;
288 			if (number >= num_found)
289 				num_found = number + 1;
290 		}
291 		nodes[found] = 0;
292 	}
293 
294 	/* Add any nodes not mentioned by an alias */
295 	for (i = j = 0; i < maxcount; i++) {
296 		if (!node_list[i]) {
297 			for (; j < maxcount; j++)
298 				if (nodes[j] &&
299 					fdtdec_get_is_enabled(blob, nodes[j]))
300 					break;
301 
302 			/* Have we run out of nodes to add? */
303 			if (j == maxcount)
304 				break;
305 
306 			assert(!node_list[i]);
307 			node_list[i] = nodes[j++];
308 			if (i >= num_found)
309 				num_found = i + 1;
310 		}
311 	}
312 
313 	return num_found;
314 }
315 
316 int fdtdec_check_fdt(void)
317 {
318 	/*
319 	 * We must have an FDT, but we cannot panic() yet since the console
320 	 * is not ready. So for now, just assert(). Boards which need an early
321 	 * FDT (prior to console ready) will need to make their own
322 	 * arrangements and do their own checks.
323 	 */
324 	assert(!fdtdec_prepare_fdt());
325 	return 0;
326 }
327 
328 /*
329  * This function is a little odd in that it accesses global data. At some
330  * point if the architecture board.c files merge this will make more sense.
331  * Even now, it is common code.
332  */
333 int fdtdec_prepare_fdt(void)
334 {
335 	if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob)) {
336 		printf("No valid FDT found - please append one to U-Boot "
337 			"binary, use u-boot-dtb.bin or define "
338 			"CONFIG_OF_EMBED\n");
339 		return -1;
340 	}
341 	return 0;
342 }
343 
344 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
345 {
346 	const u32 *phandle;
347 	int lookup;
348 
349 	debug("%s: %s\n", __func__, prop_name);
350 	phandle = fdt_getprop(blob, node, prop_name, NULL);
351 	if (!phandle)
352 		return -FDT_ERR_NOTFOUND;
353 
354 	lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
355 	return lookup;
356 }
357 
358 /**
359  * Look up a property in a node and check that it has a minimum length.
360  *
361  * @param blob		FDT blob
362  * @param node		node to examine
363  * @param prop_name	name of property to find
364  * @param min_len	minimum property length in bytes
365  * @param err		0 if ok, or -FDT_ERR_NOTFOUND if the property is not
366 			found, or -FDT_ERR_BADLAYOUT if not enough data
367  * @return pointer to cell, which is only valid if err == 0
368  */
369 static const void *get_prop_check_min_len(const void *blob, int node,
370 		const char *prop_name, int min_len, int *err)
371 {
372 	const void *cell;
373 	int len;
374 
375 	debug("%s: %s\n", __func__, prop_name);
376 	cell = fdt_getprop(blob, node, prop_name, &len);
377 	if (!cell)
378 		*err = -FDT_ERR_NOTFOUND;
379 	else if (len < min_len)
380 		*err = -FDT_ERR_BADLAYOUT;
381 	else
382 		*err = 0;
383 	return cell;
384 }
385 
386 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
387 		u32 *array, int count)
388 {
389 	const u32 *cell;
390 	int i, err = 0;
391 
392 	debug("%s: %s\n", __func__, prop_name);
393 	cell = get_prop_check_min_len(blob, node, prop_name,
394 				      sizeof(u32) * count, &err);
395 	if (!err) {
396 		for (i = 0; i < count; i++)
397 			array[i] = fdt32_to_cpu(cell[i]);
398 	}
399 	return err;
400 }
401 
402 const u32 *fdtdec_locate_array(const void *blob, int node,
403 			       const char *prop_name, int count)
404 {
405 	const u32 *cell;
406 	int err;
407 
408 	cell = get_prop_check_min_len(blob, node, prop_name,
409 				      sizeof(u32) * count, &err);
410 	return err ? NULL : cell;
411 }
412 
413 int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
414 {
415 	const s32 *cell;
416 	int len;
417 
418 	debug("%s: %s\n", __func__, prop_name);
419 	cell = fdt_getprop(blob, node, prop_name, &len);
420 	return cell != NULL;
421 }
422 
423 /**
424  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
425  * terminating item.
426  *
427  * @param blob		FDT blob to use
428  * @param node		Node to look at
429  * @param prop_name	Node property name
430  * @param gpio		Array of gpio elements to fill from FDT. This will be
431  *			untouched if either 0 or an error is returned
432  * @param max_count	Maximum number of elements allowed
433  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
434  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
435  */
436 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
437 		struct fdt_gpio_state *gpio, int max_count)
438 {
439 	const struct fdt_property *prop;
440 	const u32 *cell;
441 	const char *name;
442 	int len, i;
443 
444 	debug("%s: %s\n", __func__, prop_name);
445 	assert(max_count > 0);
446 	prop = fdt_get_property(blob, node, prop_name, &len);
447 	if (!prop) {
448 		debug("%s: property '%s' missing\n", __func__, prop_name);
449 		return -FDT_ERR_NOTFOUND;
450 	}
451 
452 	/* We will use the name to tag the GPIO */
453 	name = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
454 	cell = (u32 *)prop->data;
455 	len /= sizeof(u32) * 3;		/* 3 cells per GPIO record */
456 	if (len > max_count) {
457 		debug(" %s: too many GPIOs / cells for "
458 			"property '%s'\n", __func__, prop_name);
459 		return -FDT_ERR_BADLAYOUT;
460 	}
461 
462 	/* Read out the GPIO data from the cells */
463 	for (i = 0; i < len; i++, cell += 3) {
464 		gpio[i].gpio = fdt32_to_cpu(cell[1]);
465 		gpio[i].flags = fdt32_to_cpu(cell[2]);
466 		gpio[i].name = name;
467 	}
468 
469 	return len;
470 }
471 
472 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
473 		struct fdt_gpio_state *gpio)
474 {
475 	int err;
476 
477 	debug("%s: %s\n", __func__, prop_name);
478 	gpio->gpio = FDT_GPIO_NONE;
479 	gpio->name = NULL;
480 	err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1);
481 	return err == 1 ? 0 : err;
482 }
483 
484 int fdtdec_get_gpio(struct fdt_gpio_state *gpio)
485 {
486 	int val;
487 
488 	if (!fdt_gpio_isvalid(gpio))
489 		return -1;
490 
491 	val = gpio_get_value(gpio->gpio);
492 	return gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
493 }
494 
495 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val)
496 {
497 	if (!fdt_gpio_isvalid(gpio))
498 		return -1;
499 
500 	val = gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
501 	return gpio_set_value(gpio->gpio, val);
502 }
503 
504 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio)
505 {
506 	/*
507 	 * Return success if there is no GPIO defined. This is used for
508 	 * optional GPIOs)
509 	 */
510 	if (!fdt_gpio_isvalid(gpio))
511 		return 0;
512 
513 	if (gpio_request(gpio->gpio, gpio->name))
514 		return -1;
515 	return 0;
516 }
517 
518 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
519 		u8 *array, int count)
520 {
521 	const u8 *cell;
522 	int err;
523 
524 	cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
525 	if (!err)
526 		memcpy(array, cell, count);
527 	return err;
528 }
529 
530 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
531 			     const char *prop_name, int count)
532 {
533 	const u8 *cell;
534 	int err;
535 
536 	cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
537 	if (err)
538 		return NULL;
539 	return cell;
540 }
541 
542 int fdtdec_get_config_int(const void *blob, const char *prop_name,
543 		int default_val)
544 {
545 	int config_node;
546 
547 	debug("%s: %s\n", __func__, prop_name);
548 	config_node = fdt_path_offset(blob, "/config");
549 	if (config_node < 0)
550 		return default_val;
551 	return fdtdec_get_int(blob, config_node, prop_name, default_val);
552 }
553 
554 int fdtdec_get_config_bool(const void *blob, const char *prop_name)
555 {
556 	int config_node;
557 	const void *prop;
558 
559 	debug("%s: %s\n", __func__, prop_name);
560 	config_node = fdt_path_offset(blob, "/config");
561 	if (config_node < 0)
562 		return 0;
563 	prop = fdt_get_property(blob, config_node, prop_name, NULL);
564 
565 	return prop != NULL;
566 }
567 
568 char *fdtdec_get_config_string(const void *blob, const char *prop_name)
569 {
570 	const char *nodep;
571 	int nodeoffset;
572 	int len;
573 
574 	debug("%s: %s\n", __func__, prop_name);
575 	nodeoffset = fdt_path_offset(blob, "/config");
576 	if (nodeoffset < 0)
577 		return NULL;
578 
579 	nodep = fdt_getprop(blob, nodeoffset, prop_name, &len);
580 	if (!nodep)
581 		return NULL;
582 
583 	return (char *)nodep;
584 }
585 
586 int fdtdec_decode_region(const void *blob, int node,
587 		const char *prop_name, void **ptrp, size_t *size)
588 {
589 	const fdt_addr_t *cell;
590 	int len;
591 
592 	debug("%s: %s\n", __func__, prop_name);
593 	cell = fdt_getprop(blob, node, prop_name, &len);
594 	if (!cell || (len != sizeof(fdt_addr_t) * 2))
595 		return -1;
596 
597 	*ptrp = (void *)fdt_addr_to_cpu(*cell);
598 	*size = fdt_size_to_cpu(cell[1]);
599 	debug("%s: size=%zx\n", __func__, *size);
600 	return 0;
601 }
602