xref: /openbmc/u-boot/lib/fdtdec.c (revision 8faefadb7305b95d02df38bd2ea61429d59483e5)
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(NVIDIA_TEGRA114_SPI, "nvidia,tegra114-spi"),
54 	COMPAT(SMSC_LAN9215, "smsc,lan9215"),
55 	COMPAT(SAMSUNG_EXYNOS5_SROMC, "samsung,exynos-sromc"),
56 	COMPAT(SAMSUNG_S3C2440_I2C, "samsung,s3c2440-i2c"),
57 	COMPAT(SAMSUNG_EXYNOS5_SOUND, "samsung,exynos-sound"),
58 	COMPAT(WOLFSON_WM8994_CODEC, "wolfson,wm8994-codec"),
59 	COMPAT(SAMSUNG_EXYNOS_SPI, "samsung,exynos-spi"),
60 	COMPAT(SAMSUNG_EXYNOS_EHCI, "samsung,exynos-ehci"),
61 	COMPAT(SAMSUNG_EXYNOS_USB_PHY, "samsung,exynos-usb-phy"),
62 	COMPAT(SAMSUNG_EXYNOS_TMU, "samsung,exynos-tmu"),
63 	COMPAT(MAXIM_MAX77686_PMIC, "maxim,max77686_pmic"),
64 	COMPAT(GENERIC_SPI_FLASH, "spi-flash"),
65 	COMPAT(MAXIM_98095_CODEC, "maxim,max98095-codec"),
66 };
67 
68 const char *fdtdec_get_compatible(enum fdt_compat_id id)
69 {
70 	/* We allow reading of the 'unknown' ID for testing purposes */
71 	assert(id >= 0 && id < COMPAT_COUNT);
72 	return compat_names[id];
73 }
74 
75 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
76 		const char *prop_name, fdt_size_t *sizep)
77 {
78 	const fdt_addr_t *cell;
79 	int len;
80 
81 	debug("%s: %s: ", __func__, prop_name);
82 	cell = fdt_getprop(blob, node, prop_name, &len);
83 	if (cell && ((!sizep && len == sizeof(fdt_addr_t)) ||
84 		     len == sizeof(fdt_addr_t) * 2)) {
85 		fdt_addr_t addr = fdt_addr_to_cpu(*cell);
86 		if (sizep) {
87 			const fdt_size_t *size;
88 
89 			size = (fdt_size_t *)((char *)cell +
90 					sizeof(fdt_addr_t));
91 			*sizep = fdt_size_to_cpu(*size);
92 			debug("addr=%p, size=%p\n", (void *)addr,
93 			      (void *)*sizep);
94 		} else {
95 			debug("%p\n", (void *)addr);
96 		}
97 		return addr;
98 	}
99 	debug("(not found)\n");
100 	return FDT_ADDR_T_NONE;
101 }
102 
103 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
104 		const char *prop_name)
105 {
106 	return fdtdec_get_addr_size(blob, node, prop_name, NULL);
107 }
108 
109 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
110 		s32 default_val)
111 {
112 	const s32 *cell;
113 	int len;
114 
115 	debug("%s: %s: ", __func__, prop_name);
116 	cell = fdt_getprop(blob, node, prop_name, &len);
117 	if (cell && len >= sizeof(s32)) {
118 		s32 val = fdt32_to_cpu(cell[0]);
119 
120 		debug("%#x (%d)\n", val, val);
121 		return val;
122 	}
123 	debug("(not found)\n");
124 	return default_val;
125 }
126 
127 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
128 		uint64_t default_val)
129 {
130 	const uint64_t *cell64;
131 	int length;
132 
133 	cell64 = fdt_getprop(blob, node, prop_name, &length);
134 	if (!cell64 || length < sizeof(*cell64))
135 		return default_val;
136 
137 	return fdt64_to_cpu(*cell64);
138 }
139 
140 int fdtdec_get_is_enabled(const void *blob, int node)
141 {
142 	const char *cell;
143 
144 	/*
145 	 * It should say "okay", so only allow that. Some fdts use "ok" but
146 	 * this is a bug. Please fix your device tree source file. See here
147 	 * for discussion:
148 	 *
149 	 * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html
150 	 */
151 	cell = fdt_getprop(blob, node, "status", NULL);
152 	if (cell)
153 		return 0 == strcmp(cell, "okay");
154 	return 1;
155 }
156 
157 enum fdt_compat_id fdtdec_lookup(const void *blob, int node)
158 {
159 	enum fdt_compat_id id;
160 
161 	/* Search our drivers */
162 	for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
163 		if (0 == fdt_node_check_compatible(blob, node,
164 				compat_names[id]))
165 			return id;
166 	return COMPAT_UNKNOWN;
167 }
168 
169 int fdtdec_next_compatible(const void *blob, int node,
170 		enum fdt_compat_id id)
171 {
172 	return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
173 }
174 
175 int fdtdec_next_compatible_subnode(const void *blob, int node,
176 		enum fdt_compat_id id, int *depthp)
177 {
178 	do {
179 		node = fdt_next_node(blob, node, depthp);
180 	} while (*depthp > 1);
181 
182 	/* If this is a direct subnode, and compatible, return it */
183 	if (*depthp == 1 && 0 == fdt_node_check_compatible(
184 						blob, node, compat_names[id]))
185 		return node;
186 
187 	return -FDT_ERR_NOTFOUND;
188 }
189 
190 int fdtdec_next_alias(const void *blob, const char *name,
191 		enum fdt_compat_id id, int *upto)
192 {
193 #define MAX_STR_LEN 20
194 	char str[MAX_STR_LEN + 20];
195 	int node, err;
196 
197 	/* snprintf() is not available */
198 	assert(strlen(name) < MAX_STR_LEN);
199 	sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto);
200 	node = fdt_path_offset(blob, str);
201 	if (node < 0)
202 		return node;
203 	err = fdt_node_check_compatible(blob, node, compat_names[id]);
204 	if (err < 0)
205 		return err;
206 	if (err)
207 		return -FDT_ERR_NOTFOUND;
208 	(*upto)++;
209 	return node;
210 }
211 
212 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
213 			enum fdt_compat_id id, int *node_list, int maxcount)
214 {
215 	memset(node_list, '\0', sizeof(*node_list) * maxcount);
216 
217 	return fdtdec_add_aliases_for_id(blob, name, id, node_list, maxcount);
218 }
219 
220 /* TODO: Can we tighten this code up a little? */
221 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
222 			enum fdt_compat_id id, int *node_list, int maxcount)
223 {
224 	int name_len = strlen(name);
225 	int nodes[maxcount];
226 	int num_found = 0;
227 	int offset, node;
228 	int alias_node;
229 	int count;
230 	int i, j;
231 
232 	/* find the alias node if present */
233 	alias_node = fdt_path_offset(blob, "/aliases");
234 
235 	/*
236 	 * start with nothing, and we can assume that the root node can't
237 	 * match
238 	 */
239 	memset(nodes, '\0', sizeof(nodes));
240 
241 	/* First find all the compatible nodes */
242 	for (node = count = 0; node >= 0 && count < maxcount;) {
243 		node = fdtdec_next_compatible(blob, node, id);
244 		if (node >= 0)
245 			nodes[count++] = node;
246 	}
247 	if (node >= 0)
248 		debug("%s: warning: maxcount exceeded with alias '%s'\n",
249 		       __func__, name);
250 
251 	/* Now find all the aliases */
252 	for (offset = fdt_first_property_offset(blob, alias_node);
253 			offset > 0;
254 			offset = fdt_next_property_offset(blob, offset)) {
255 		const struct fdt_property *prop;
256 		const char *path;
257 		int number;
258 		int found;
259 
260 		node = 0;
261 		prop = fdt_get_property_by_offset(blob, offset, NULL);
262 		path = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
263 		if (prop->len && 0 == strncmp(path, name, name_len))
264 			node = fdt_path_offset(blob, prop->data);
265 		if (node <= 0)
266 			continue;
267 
268 		/* Get the alias number */
269 		number = simple_strtoul(path + name_len, NULL, 10);
270 		if (number < 0 || number >= maxcount) {
271 			debug("%s: warning: alias '%s' is out of range\n",
272 			       __func__, path);
273 			continue;
274 		}
275 
276 		/* Make sure the node we found is actually in our list! */
277 		found = -1;
278 		for (j = 0; j < count; j++)
279 			if (nodes[j] == node) {
280 				found = j;
281 				break;
282 			}
283 
284 		if (found == -1) {
285 			debug("%s: warning: alias '%s' points to a node "
286 				"'%s' that is missing or is not compatible "
287 				" with '%s'\n", __func__, path,
288 				fdt_get_name(blob, node, NULL),
289 			       compat_names[id]);
290 			continue;
291 		}
292 
293 		/*
294 		 * Add this node to our list in the right place, and mark
295 		 * it as done.
296 		 */
297 		if (fdtdec_get_is_enabled(blob, node)) {
298 			if (node_list[number]) {
299 				debug("%s: warning: alias '%s' requires that "
300 				      "a node be placed in the list in a "
301 				      "position which is already filled by "
302 				      "node '%s'\n", __func__, path,
303 				      fdt_get_name(blob, node, NULL));
304 				continue;
305 			}
306 			node_list[number] = node;
307 			if (number >= num_found)
308 				num_found = number + 1;
309 		}
310 		nodes[found] = 0;
311 	}
312 
313 	/* Add any nodes not mentioned by an alias */
314 	for (i = j = 0; i < maxcount; i++) {
315 		if (!node_list[i]) {
316 			for (; j < maxcount; j++)
317 				if (nodes[j] &&
318 					fdtdec_get_is_enabled(blob, nodes[j]))
319 					break;
320 
321 			/* Have we run out of nodes to add? */
322 			if (j == maxcount)
323 				break;
324 
325 			assert(!node_list[i]);
326 			node_list[i] = nodes[j++];
327 			if (i >= num_found)
328 				num_found = i + 1;
329 		}
330 	}
331 
332 	return num_found;
333 }
334 
335 int fdtdec_check_fdt(void)
336 {
337 	/*
338 	 * We must have an FDT, but we cannot panic() yet since the console
339 	 * is not ready. So for now, just assert(). Boards which need an early
340 	 * FDT (prior to console ready) will need to make their own
341 	 * arrangements and do their own checks.
342 	 */
343 	assert(!fdtdec_prepare_fdt());
344 	return 0;
345 }
346 
347 /*
348  * This function is a little odd in that it accesses global data. At some
349  * point if the architecture board.c files merge this will make more sense.
350  * Even now, it is common code.
351  */
352 int fdtdec_prepare_fdt(void)
353 {
354 	if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob)) {
355 		printf("No valid FDT found - please append one to U-Boot "
356 			"binary, use u-boot-dtb.bin or define "
357 			"CONFIG_OF_EMBED\n");
358 		return -1;
359 	}
360 	return 0;
361 }
362 
363 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
364 {
365 	const u32 *phandle;
366 	int lookup;
367 
368 	debug("%s: %s\n", __func__, prop_name);
369 	phandle = fdt_getprop(blob, node, prop_name, NULL);
370 	if (!phandle)
371 		return -FDT_ERR_NOTFOUND;
372 
373 	lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
374 	return lookup;
375 }
376 
377 /**
378  * Look up a property in a node and check that it has a minimum length.
379  *
380  * @param blob		FDT blob
381  * @param node		node to examine
382  * @param prop_name	name of property to find
383  * @param min_len	minimum property length in bytes
384  * @param err		0 if ok, or -FDT_ERR_NOTFOUND if the property is not
385 			found, or -FDT_ERR_BADLAYOUT if not enough data
386  * @return pointer to cell, which is only valid if err == 0
387  */
388 static const void *get_prop_check_min_len(const void *blob, int node,
389 		const char *prop_name, int min_len, int *err)
390 {
391 	const void *cell;
392 	int len;
393 
394 	debug("%s: %s\n", __func__, prop_name);
395 	cell = fdt_getprop(blob, node, prop_name, &len);
396 	if (!cell)
397 		*err = -FDT_ERR_NOTFOUND;
398 	else if (len < min_len)
399 		*err = -FDT_ERR_BADLAYOUT;
400 	else
401 		*err = 0;
402 	return cell;
403 }
404 
405 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
406 		u32 *array, int count)
407 {
408 	const u32 *cell;
409 	int i, err = 0;
410 
411 	debug("%s: %s\n", __func__, prop_name);
412 	cell = get_prop_check_min_len(blob, node, prop_name,
413 				      sizeof(u32) * count, &err);
414 	if (!err) {
415 		for (i = 0; i < count; i++)
416 			array[i] = fdt32_to_cpu(cell[i]);
417 	}
418 	return err;
419 }
420 
421 const u32 *fdtdec_locate_array(const void *blob, int node,
422 			       const char *prop_name, int count)
423 {
424 	const u32 *cell;
425 	int err;
426 
427 	cell = get_prop_check_min_len(blob, node, prop_name,
428 				      sizeof(u32) * count, &err);
429 	return err ? NULL : cell;
430 }
431 
432 int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
433 {
434 	const s32 *cell;
435 	int len;
436 
437 	debug("%s: %s\n", __func__, prop_name);
438 	cell = fdt_getprop(blob, node, prop_name, &len);
439 	return cell != NULL;
440 }
441 
442 /**
443  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
444  * terminating item.
445  *
446  * @param blob		FDT blob to use
447  * @param node		Node to look at
448  * @param prop_name	Node property name
449  * @param gpio		Array of gpio elements to fill from FDT. This will be
450  *			untouched if either 0 or an error is returned
451  * @param max_count	Maximum number of elements allowed
452  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
453  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
454  */
455 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
456 		struct fdt_gpio_state *gpio, int max_count)
457 {
458 	const struct fdt_property *prop;
459 	const u32 *cell;
460 	const char *name;
461 	int len, i;
462 
463 	debug("%s: %s\n", __func__, prop_name);
464 	assert(max_count > 0);
465 	prop = fdt_get_property(blob, node, prop_name, &len);
466 	if (!prop) {
467 		debug("%s: property '%s' missing\n", __func__, prop_name);
468 		return -FDT_ERR_NOTFOUND;
469 	}
470 
471 	/* We will use the name to tag the GPIO */
472 	name = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
473 	cell = (u32 *)prop->data;
474 	len /= sizeof(u32) * 3;		/* 3 cells per GPIO record */
475 	if (len > max_count) {
476 		debug(" %s: too many GPIOs / cells for "
477 			"property '%s'\n", __func__, prop_name);
478 		return -FDT_ERR_BADLAYOUT;
479 	}
480 
481 	/* Read out the GPIO data from the cells */
482 	for (i = 0; i < len; i++, cell += 3) {
483 		gpio[i].gpio = fdt32_to_cpu(cell[1]);
484 		gpio[i].flags = fdt32_to_cpu(cell[2]);
485 		gpio[i].name = name;
486 	}
487 
488 	return len;
489 }
490 
491 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
492 		struct fdt_gpio_state *gpio)
493 {
494 	int err;
495 
496 	debug("%s: %s\n", __func__, prop_name);
497 	gpio->gpio = FDT_GPIO_NONE;
498 	gpio->name = NULL;
499 	err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1);
500 	return err == 1 ? 0 : err;
501 }
502 
503 int fdtdec_get_gpio(struct fdt_gpio_state *gpio)
504 {
505 	int val;
506 
507 	if (!fdt_gpio_isvalid(gpio))
508 		return -1;
509 
510 	val = gpio_get_value(gpio->gpio);
511 	return gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
512 }
513 
514 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val)
515 {
516 	if (!fdt_gpio_isvalid(gpio))
517 		return -1;
518 
519 	val = gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
520 	return gpio_set_value(gpio->gpio, val);
521 }
522 
523 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio)
524 {
525 	/*
526 	 * Return success if there is no GPIO defined. This is used for
527 	 * optional GPIOs)
528 	 */
529 	if (!fdt_gpio_isvalid(gpio))
530 		return 0;
531 
532 	if (gpio_request(gpio->gpio, gpio->name))
533 		return -1;
534 	return 0;
535 }
536 
537 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
538 		u8 *array, int count)
539 {
540 	const u8 *cell;
541 	int err;
542 
543 	cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
544 	if (!err)
545 		memcpy(array, cell, count);
546 	return err;
547 }
548 
549 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
550 			     const char *prop_name, int count)
551 {
552 	const u8 *cell;
553 	int err;
554 
555 	cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
556 	if (err)
557 		return NULL;
558 	return cell;
559 }
560 
561 int fdtdec_get_config_int(const void *blob, const char *prop_name,
562 		int default_val)
563 {
564 	int config_node;
565 
566 	debug("%s: %s\n", __func__, prop_name);
567 	config_node = fdt_path_offset(blob, "/config");
568 	if (config_node < 0)
569 		return default_val;
570 	return fdtdec_get_int(blob, config_node, prop_name, default_val);
571 }
572 
573 int fdtdec_get_config_bool(const void *blob, const char *prop_name)
574 {
575 	int config_node;
576 	const void *prop;
577 
578 	debug("%s: %s\n", __func__, prop_name);
579 	config_node = fdt_path_offset(blob, "/config");
580 	if (config_node < 0)
581 		return 0;
582 	prop = fdt_get_property(blob, config_node, prop_name, NULL);
583 
584 	return prop != NULL;
585 }
586 
587 char *fdtdec_get_config_string(const void *blob, const char *prop_name)
588 {
589 	const char *nodep;
590 	int nodeoffset;
591 	int len;
592 
593 	debug("%s: %s\n", __func__, prop_name);
594 	nodeoffset = fdt_path_offset(blob, "/config");
595 	if (nodeoffset < 0)
596 		return NULL;
597 
598 	nodep = fdt_getprop(blob, nodeoffset, prop_name, &len);
599 	if (!nodep)
600 		return NULL;
601 
602 	return (char *)nodep;
603 }
604 
605 int fdtdec_decode_region(const void *blob, int node,
606 		const char *prop_name, void **ptrp, size_t *size)
607 {
608 	const fdt_addr_t *cell;
609 	int len;
610 
611 	debug("%s: %s\n", __func__, prop_name);
612 	cell = fdt_getprop(blob, node, prop_name, &len);
613 	if (!cell || (len != sizeof(fdt_addr_t) * 2))
614 		return -1;
615 
616 	*ptrp = (void *)fdt_addr_to_cpu(*cell);
617 	*size = fdt_size_to_cpu(cell[1]);
618 	debug("%s: size=%zx\n", __func__, *size);
619 	return 0;
620 }
621