xref: /openbmc/u-boot/lib/fdtdec.c (revision c9aa831e)
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_TEGRA20_SDMMC, "nvidia,tegra20-sdhci"),
50 	COMPAT(NVIDIA_TEGRA20_SFLASH, "nvidia,tegra20-sflash"),
51 	COMPAT(NVIDIA_TEGRA20_SLINK, "nvidia,tegra20-slink"),
52 	COMPAT(SMSC_LAN9215, "smsc,lan9215"),
53 	COMPAT(SAMSUNG_EXYNOS5_SROMC, "samsung,exynos-sromc"),
54 	COMPAT(SAMSUNG_S3C2440_I2C, "samsung,s3c2440-i2c"),
55 	COMPAT(SAMSUNG_EXYNOS5_SOUND, "samsung,exynos-sound"),
56 	COMPAT(WOLFSON_WM8994_CODEC, "wolfson,wm8994-codec"),
57 	COMPAT(SAMSUNG_EXYNOS_SPI, "samsung,exynos-spi"),
58 	COMPAT(SAMSUNG_EXYNOS_EHCI, "samsung,exynos-ehci"),
59 	COMPAT(SAMSUNG_EXYNOS_USB_PHY, "samsung,exynos-usb-phy"),
60 	COMPAT(MAXIM_MAX77686_PMIC, "maxim,max77686_pmic"),
61 };
62 
63 const char *fdtdec_get_compatible(enum fdt_compat_id id)
64 {
65 	/* We allow reading of the 'unknown' ID for testing purposes */
66 	assert(id >= 0 && id < COMPAT_COUNT);
67 	return compat_names[id];
68 }
69 
70 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
71 		const char *prop_name)
72 {
73 	const fdt_addr_t *cell;
74 	int len;
75 
76 	debug("%s: %s: ", __func__, prop_name);
77 	cell = fdt_getprop(blob, node, prop_name, &len);
78 	if (cell && (len == sizeof(fdt_addr_t) ||
79 			len == sizeof(fdt_addr_t) * 2)) {
80 		fdt_addr_t addr = fdt_addr_to_cpu(*cell);
81 
82 		debug("%p\n", (void *)addr);
83 		return addr;
84 	}
85 	debug("(not found)\n");
86 	return FDT_ADDR_T_NONE;
87 }
88 
89 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
90 		s32 default_val)
91 {
92 	const s32 *cell;
93 	int len;
94 
95 	debug("%s: %s: ", __func__, prop_name);
96 	cell = fdt_getprop(blob, node, prop_name, &len);
97 	if (cell && len >= sizeof(s32)) {
98 		s32 val = fdt32_to_cpu(cell[0]);
99 
100 		debug("%#x (%d)\n", val, val);
101 		return val;
102 	}
103 	debug("(not found)\n");
104 	return default_val;
105 }
106 
107 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
108 		uint64_t default_val)
109 {
110 	const uint64_t *cell64;
111 	int length;
112 
113 	cell64 = fdt_getprop(blob, node, prop_name, &length);
114 	if (!cell64 || length < sizeof(*cell64))
115 		return default_val;
116 
117 	return fdt64_to_cpu(*cell64);
118 }
119 
120 int fdtdec_get_is_enabled(const void *blob, int node)
121 {
122 	const char *cell;
123 
124 	/*
125 	 * It should say "okay", so only allow that. Some fdts use "ok" but
126 	 * this is a bug. Please fix your device tree source file. See here
127 	 * for discussion:
128 	 *
129 	 * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html
130 	 */
131 	cell = fdt_getprop(blob, node, "status", NULL);
132 	if (cell)
133 		return 0 == strcmp(cell, "okay");
134 	return 1;
135 }
136 
137 enum fdt_compat_id fdtdec_lookup(const void *blob, int node)
138 {
139 	enum fdt_compat_id id;
140 
141 	/* Search our drivers */
142 	for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
143 		if (0 == fdt_node_check_compatible(blob, node,
144 				compat_names[id]))
145 			return id;
146 	return COMPAT_UNKNOWN;
147 }
148 
149 int fdtdec_next_compatible(const void *blob, int node,
150 		enum fdt_compat_id id)
151 {
152 	return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
153 }
154 
155 int fdtdec_next_compatible_subnode(const void *blob, int node,
156 		enum fdt_compat_id id, int *depthp)
157 {
158 	do {
159 		node = fdt_next_node(blob, node, depthp);
160 	} while (*depthp > 1);
161 
162 	/* If this is a direct subnode, and compatible, return it */
163 	if (*depthp == 1 && 0 == fdt_node_check_compatible(
164 						blob, node, compat_names[id]))
165 		return node;
166 
167 	return -FDT_ERR_NOTFOUND;
168 }
169 
170 int fdtdec_next_alias(const void *blob, const char *name,
171 		enum fdt_compat_id id, int *upto)
172 {
173 #define MAX_STR_LEN 20
174 	char str[MAX_STR_LEN + 20];
175 	int node, err;
176 
177 	/* snprintf() is not available */
178 	assert(strlen(name) < MAX_STR_LEN);
179 	sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto);
180 	node = fdt_path_offset(blob, str);
181 	if (node < 0)
182 		return node;
183 	err = fdt_node_check_compatible(blob, node, compat_names[id]);
184 	if (err < 0)
185 		return err;
186 	if (err)
187 		return -FDT_ERR_NOTFOUND;
188 	(*upto)++;
189 	return node;
190 }
191 
192 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
193 			enum fdt_compat_id id, int *node_list, int maxcount)
194 {
195 	memset(node_list, '\0', sizeof(*node_list) * maxcount);
196 
197 	return fdtdec_add_aliases_for_id(blob, name, id, node_list, maxcount);
198 }
199 
200 /* TODO: Can we tighten this code up a little? */
201 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
202 			enum fdt_compat_id id, int *node_list, int maxcount)
203 {
204 	int name_len = strlen(name);
205 	int nodes[maxcount];
206 	int num_found = 0;
207 	int offset, node;
208 	int alias_node;
209 	int count;
210 	int i, j;
211 
212 	/* find the alias node if present */
213 	alias_node = fdt_path_offset(blob, "/aliases");
214 
215 	/*
216 	 * start with nothing, and we can assume that the root node can't
217 	 * match
218 	 */
219 	memset(nodes, '\0', sizeof(nodes));
220 
221 	/* First find all the compatible nodes */
222 	for (node = count = 0; node >= 0 && count < maxcount;) {
223 		node = fdtdec_next_compatible(blob, node, id);
224 		if (node >= 0)
225 			nodes[count++] = node;
226 	}
227 	if (node >= 0)
228 		debug("%s: warning: maxcount exceeded with alias '%s'\n",
229 		       __func__, name);
230 
231 	/* Now find all the aliases */
232 	for (offset = fdt_first_property_offset(blob, alias_node);
233 			offset > 0;
234 			offset = fdt_next_property_offset(blob, offset)) {
235 		const struct fdt_property *prop;
236 		const char *path;
237 		int number;
238 		int found;
239 
240 		node = 0;
241 		prop = fdt_get_property_by_offset(blob, offset, NULL);
242 		path = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
243 		if (prop->len && 0 == strncmp(path, name, name_len))
244 			node = fdt_path_offset(blob, prop->data);
245 		if (node <= 0)
246 			continue;
247 
248 		/* Get the alias number */
249 		number = simple_strtoul(path + name_len, NULL, 10);
250 		if (number < 0 || number >= maxcount) {
251 			debug("%s: warning: alias '%s' is out of range\n",
252 			       __func__, path);
253 			continue;
254 		}
255 
256 		/* Make sure the node we found is actually in our list! */
257 		found = -1;
258 		for (j = 0; j < count; j++)
259 			if (nodes[j] == node) {
260 				found = j;
261 				break;
262 			}
263 
264 		if (found == -1) {
265 			debug("%s: warning: alias '%s' points to a node "
266 				"'%s' that is missing or is not compatible "
267 				" with '%s'\n", __func__, path,
268 				fdt_get_name(blob, node, NULL),
269 			       compat_names[id]);
270 			continue;
271 		}
272 
273 		/*
274 		 * Add this node to our list in the right place, and mark
275 		 * it as done.
276 		 */
277 		if (fdtdec_get_is_enabled(blob, node)) {
278 			if (node_list[number]) {
279 				debug("%s: warning: alias '%s' requires that "
280 				      "a node be placed in the list in a "
281 				      "position which is already filled by "
282 				      "node '%s'\n", __func__, path,
283 				      fdt_get_name(blob, node, NULL));
284 				continue;
285 			}
286 			node_list[number] = node;
287 			if (number >= num_found)
288 				num_found = number + 1;
289 		}
290 		nodes[found] = 0;
291 	}
292 
293 	/* Add any nodes not mentioned by an alias */
294 	for (i = j = 0; i < maxcount; i++) {
295 		if (!node_list[i]) {
296 			for (; j < maxcount; j++)
297 				if (nodes[j] &&
298 					fdtdec_get_is_enabled(blob, nodes[j]))
299 					break;
300 
301 			/* Have we run out of nodes to add? */
302 			if (j == maxcount)
303 				break;
304 
305 			assert(!node_list[i]);
306 			node_list[i] = nodes[j++];
307 			if (i >= num_found)
308 				num_found = i + 1;
309 		}
310 	}
311 
312 	return num_found;
313 }
314 
315 int fdtdec_check_fdt(void)
316 {
317 	/*
318 	 * We must have an FDT, but we cannot panic() yet since the console
319 	 * is not ready. So for now, just assert(). Boards which need an early
320 	 * FDT (prior to console ready) will need to make their own
321 	 * arrangements and do their own checks.
322 	 */
323 	assert(!fdtdec_prepare_fdt());
324 	return 0;
325 }
326 
327 /*
328  * This function is a little odd in that it accesses global data. At some
329  * point if the architecture board.c files merge this will make more sense.
330  * Even now, it is common code.
331  */
332 int fdtdec_prepare_fdt(void)
333 {
334 	if (((uintptr_t)gd->fdt_blob & 3) || fdt_check_header(gd->fdt_blob)) {
335 		printf("No valid FDT found - please append one to U-Boot "
336 			"binary, use u-boot-dtb.bin or define "
337 			"CONFIG_OF_EMBED\n");
338 		return -1;
339 	}
340 	return 0;
341 }
342 
343 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
344 {
345 	const u32 *phandle;
346 	int lookup;
347 
348 	debug("%s: %s\n", __func__, prop_name);
349 	phandle = fdt_getprop(blob, node, prop_name, NULL);
350 	if (!phandle)
351 		return -FDT_ERR_NOTFOUND;
352 
353 	lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
354 	return lookup;
355 }
356 
357 /**
358  * Look up a property in a node and check that it has a minimum length.
359  *
360  * @param blob		FDT blob
361  * @param node		node to examine
362  * @param prop_name	name of property to find
363  * @param min_len	minimum property length in bytes
364  * @param err		0 if ok, or -FDT_ERR_NOTFOUND if the property is not
365 			found, or -FDT_ERR_BADLAYOUT if not enough data
366  * @return pointer to cell, which is only valid if err == 0
367  */
368 static const void *get_prop_check_min_len(const void *blob, int node,
369 		const char *prop_name, int min_len, int *err)
370 {
371 	const void *cell;
372 	int len;
373 
374 	debug("%s: %s\n", __func__, prop_name);
375 	cell = fdt_getprop(blob, node, prop_name, &len);
376 	if (!cell)
377 		*err = -FDT_ERR_NOTFOUND;
378 	else if (len < min_len)
379 		*err = -FDT_ERR_BADLAYOUT;
380 	else
381 		*err = 0;
382 	return cell;
383 }
384 
385 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
386 		u32 *array, int count)
387 {
388 	const u32 *cell;
389 	int i, err = 0;
390 
391 	debug("%s: %s\n", __func__, prop_name);
392 	cell = get_prop_check_min_len(blob, node, prop_name,
393 				      sizeof(u32) * count, &err);
394 	if (!err) {
395 		for (i = 0; i < count; i++)
396 			array[i] = fdt32_to_cpu(cell[i]);
397 	}
398 	return err;
399 }
400 
401 const u32 *fdtdec_locate_array(const void *blob, int node,
402 			       const char *prop_name, int count)
403 {
404 	const u32 *cell;
405 	int err;
406 
407 	cell = get_prop_check_min_len(blob, node, prop_name,
408 				      sizeof(u32) * count, &err);
409 	return err ? NULL : cell;
410 }
411 
412 int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
413 {
414 	const s32 *cell;
415 	int len;
416 
417 	debug("%s: %s\n", __func__, prop_name);
418 	cell = fdt_getprop(blob, node, prop_name, &len);
419 	return cell != NULL;
420 }
421 
422 /**
423  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
424  * terminating item.
425  *
426  * @param blob		FDT blob to use
427  * @param node		Node to look at
428  * @param prop_name	Node property name
429  * @param gpio		Array of gpio elements to fill from FDT. This will be
430  *			untouched if either 0 or an error is returned
431  * @param max_count	Maximum number of elements allowed
432  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
433  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
434  */
435 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
436 		struct fdt_gpio_state *gpio, int max_count)
437 {
438 	const struct fdt_property *prop;
439 	const u32 *cell;
440 	const char *name;
441 	int len, i;
442 
443 	debug("%s: %s\n", __func__, prop_name);
444 	assert(max_count > 0);
445 	prop = fdt_get_property(blob, node, prop_name, &len);
446 	if (!prop) {
447 		debug("%s: property '%s' missing\n", __func__, prop_name);
448 		return -FDT_ERR_NOTFOUND;
449 	}
450 
451 	/* We will use the name to tag the GPIO */
452 	name = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
453 	cell = (u32 *)prop->data;
454 	len /= sizeof(u32) * 3;		/* 3 cells per GPIO record */
455 	if (len > max_count) {
456 		debug(" %s: too many GPIOs / cells for "
457 			"property '%s'\n", __func__, prop_name);
458 		return -FDT_ERR_BADLAYOUT;
459 	}
460 
461 	/* Read out the GPIO data from the cells */
462 	for (i = 0; i < len; i++, cell += 3) {
463 		gpio[i].gpio = fdt32_to_cpu(cell[1]);
464 		gpio[i].flags = fdt32_to_cpu(cell[2]);
465 		gpio[i].name = name;
466 	}
467 
468 	return len;
469 }
470 
471 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
472 		struct fdt_gpio_state *gpio)
473 {
474 	int err;
475 
476 	debug("%s: %s\n", __func__, prop_name);
477 	gpio->gpio = FDT_GPIO_NONE;
478 	gpio->name = NULL;
479 	err = fdtdec_decode_gpios(blob, node, prop_name, gpio, 1);
480 	return err == 1 ? 0 : err;
481 }
482 
483 int fdtdec_get_gpio(struct fdt_gpio_state *gpio)
484 {
485 	int val;
486 
487 	if (!fdt_gpio_isvalid(gpio))
488 		return -1;
489 
490 	val = gpio_get_value(gpio->gpio);
491 	return gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
492 }
493 
494 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val)
495 {
496 	if (!fdt_gpio_isvalid(gpio))
497 		return -1;
498 
499 	val = gpio->flags & FDT_GPIO_ACTIVE_LOW ? val ^ 1 : val;
500 	return gpio_set_value(gpio->gpio, val);
501 }
502 
503 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio)
504 {
505 	/*
506 	 * Return success if there is no GPIO defined. This is used for
507 	 * optional GPIOs)
508 	 */
509 	if (!fdt_gpio_isvalid(gpio))
510 		return 0;
511 
512 	if (gpio_request(gpio->gpio, gpio->name))
513 		return -1;
514 	return 0;
515 }
516 
517 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
518 		u8 *array, int count)
519 {
520 	const u8 *cell;
521 	int err;
522 
523 	cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
524 	if (!err)
525 		memcpy(array, cell, count);
526 	return err;
527 }
528 
529 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
530 			     const char *prop_name, int count)
531 {
532 	const u8 *cell;
533 	int err;
534 
535 	cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
536 	if (err)
537 		return NULL;
538 	return cell;
539 }
540 
541 int fdtdec_get_config_int(const void *blob, const char *prop_name,
542 		int default_val)
543 {
544 	int config_node;
545 
546 	debug("%s: %s\n", __func__, prop_name);
547 	config_node = fdt_path_offset(blob, "/config");
548 	if (config_node < 0)
549 		return default_val;
550 	return fdtdec_get_int(blob, config_node, prop_name, default_val);
551 }
552 
553 int fdtdec_get_config_bool(const void *blob, const char *prop_name)
554 {
555 	int config_node;
556 	const void *prop;
557 
558 	debug("%s: %s\n", __func__, prop_name);
559 	config_node = fdt_path_offset(blob, "/config");
560 	if (config_node < 0)
561 		return 0;
562 	prop = fdt_get_property(blob, config_node, prop_name, NULL);
563 
564 	return prop != NULL;
565 }
566 
567 char *fdtdec_get_config_string(const void *blob, const char *prop_name)
568 {
569 	const char *nodep;
570 	int nodeoffset;
571 	int len;
572 
573 	debug("%s: %s\n", __func__, prop_name);
574 	nodeoffset = fdt_path_offset(blob, "/config");
575 	if (nodeoffset < 0)
576 		return NULL;
577 
578 	nodep = fdt_getprop(blob, nodeoffset, prop_name, &len);
579 	if (!nodep)
580 		return NULL;
581 
582 	return (char *)nodep;
583 }
584 
585 int fdtdec_decode_region(const void *blob, int node,
586 		const char *prop_name, void **ptrp, size_t *size)
587 {
588 	const fdt_addr_t *cell;
589 	int len;
590 
591 	debug("%s: %s\n", __func__, prop_name);
592 	cell = fdt_getprop(blob, node, prop_name, &len);
593 	if (!cell || (len != sizeof(fdt_addr_t) * 2))
594 		return -1;
595 
596 	*ptrp = (void *)fdt_addr_to_cpu(*cell);
597 	*size = fdt_size_to_cpu(cell[1]);
598 	debug("%s: size=%zx\n", __func__, *size);
599 	return 0;
600 }
601