xref: /openbmc/u-boot/lib/fdtdec.c (revision 5e90470a)
1 /*
2  * Copyright (c) 2011 The Chromium OS Authors.
3  * SPDX-License-Identifier:	GPL-2.0+
4  */
5 
6 #ifndef USE_HOSTCC
7 #include <common.h>
8 #include <errno.h>
9 #include <serial.h>
10 #include <libfdt.h>
11 #include <fdtdec.h>
12 #include <asm/sections.h>
13 #include <linux/ctype.h>
14 
15 DECLARE_GLOBAL_DATA_PTR;
16 
17 /*
18  * Here are the type we know about. One day we might allow drivers to
19  * register. For now we just put them here. The COMPAT macro allows us to
20  * turn this into a sparse list later, and keeps the ID with the name.
21  */
22 #define COMPAT(id, name) name
23 static const char * const compat_names[COMPAT_COUNT] = {
24 	COMPAT(UNKNOWN, "<none>"),
25 	COMPAT(NVIDIA_TEGRA20_USB, "nvidia,tegra20-ehci"),
26 	COMPAT(NVIDIA_TEGRA30_USB, "nvidia,tegra30-ehci"),
27 	COMPAT(NVIDIA_TEGRA114_USB, "nvidia,tegra114-ehci"),
28 	COMPAT(NVIDIA_TEGRA20_EMC, "nvidia,tegra20-emc"),
29 	COMPAT(NVIDIA_TEGRA20_EMC_TABLE, "nvidia,tegra20-emc-table"),
30 	COMPAT(NVIDIA_TEGRA20_KBC, "nvidia,tegra20-kbc"),
31 	COMPAT(NVIDIA_TEGRA20_NAND, "nvidia,tegra20-nand"),
32 	COMPAT(NVIDIA_TEGRA20_PWM, "nvidia,tegra20-pwm"),
33 	COMPAT(NVIDIA_TEGRA124_DC, "nvidia,tegra124-dc"),
34 	COMPAT(NVIDIA_TEGRA124_SOR, "nvidia,tegra124-sor"),
35 	COMPAT(NVIDIA_TEGRA124_PMC, "nvidia,tegra124-pmc"),
36 	COMPAT(NVIDIA_TEGRA20_DC, "nvidia,tegra20-dc"),
37 	COMPAT(NVIDIA_TEGRA124_SDMMC, "nvidia,tegra124-sdhci"),
38 	COMPAT(NVIDIA_TEGRA30_SDMMC, "nvidia,tegra30-sdhci"),
39 	COMPAT(NVIDIA_TEGRA20_SDMMC, "nvidia,tegra20-sdhci"),
40 	COMPAT(NVIDIA_TEGRA124_PCIE, "nvidia,tegra124-pcie"),
41 	COMPAT(NVIDIA_TEGRA30_PCIE, "nvidia,tegra30-pcie"),
42 	COMPAT(NVIDIA_TEGRA20_PCIE, "nvidia,tegra20-pcie"),
43 	COMPAT(NVIDIA_TEGRA124_XUSB_PADCTL, "nvidia,tegra124-xusb-padctl"),
44 	COMPAT(SMSC_LAN9215, "smsc,lan9215"),
45 	COMPAT(SAMSUNG_EXYNOS5_SROMC, "samsung,exynos-sromc"),
46 	COMPAT(SAMSUNG_S3C2440_I2C, "samsung,s3c2440-i2c"),
47 	COMPAT(SAMSUNG_EXYNOS5_SOUND, "samsung,exynos-sound"),
48 	COMPAT(WOLFSON_WM8994_CODEC, "wolfson,wm8994-codec"),
49 	COMPAT(GOOGLE_CROS_EC_KEYB, "google,cros-ec-keyb"),
50 	COMPAT(SAMSUNG_EXYNOS_USB_PHY, "samsung,exynos-usb-phy"),
51 	COMPAT(SAMSUNG_EXYNOS5_USB3_PHY, "samsung,exynos5250-usb3-phy"),
52 	COMPAT(SAMSUNG_EXYNOS_TMU, "samsung,exynos-tmu"),
53 	COMPAT(SAMSUNG_EXYNOS_FIMD, "samsung,exynos-fimd"),
54 	COMPAT(SAMSUNG_EXYNOS_MIPI_DSI, "samsung,exynos-mipi-dsi"),
55 	COMPAT(SAMSUNG_EXYNOS5_DP, "samsung,exynos5-dp"),
56 	COMPAT(SAMSUNG_EXYNOS_DWMMC, "samsung,exynos-dwmmc"),
57 	COMPAT(SAMSUNG_EXYNOS_MMC, "samsung,exynos-mmc"),
58 	COMPAT(SAMSUNG_EXYNOS_SERIAL, "samsung,exynos4210-uart"),
59 	COMPAT(MAXIM_MAX77686_PMIC, "maxim,max77686"),
60 	COMPAT(GENERIC_SPI_FLASH, "spi-flash"),
61 	COMPAT(MAXIM_98095_CODEC, "maxim,max98095-codec"),
62 	COMPAT(INFINEON_SLB9635_TPM, "infineon,slb9635-tpm"),
63 	COMPAT(INFINEON_SLB9645_TPM, "infineon,slb9645tt"),
64 	COMPAT(SAMSUNG_EXYNOS5_I2C, "samsung,exynos5-hsi2c"),
65 	COMPAT(SANDBOX_LCD_SDL, "sandbox,lcd-sdl"),
66 	COMPAT(TI_TPS65090, "ti,tps65090"),
67 	COMPAT(COMPAT_NXP_PTN3460, "nxp,ptn3460"),
68 	COMPAT(SAMSUNG_EXYNOS_SYSMMU, "samsung,sysmmu-v3.3"),
69 	COMPAT(PARADE_PS8625, "parade,ps8625"),
70 	COMPAT(INTEL_MICROCODE, "intel,microcode"),
71 	COMPAT(MEMORY_SPD, "memory-spd"),
72 	COMPAT(INTEL_PANTHERPOINT_AHCI, "intel,pantherpoint-ahci"),
73 	COMPAT(INTEL_MODEL_206AX, "intel,model-206ax"),
74 	COMPAT(INTEL_GMA, "intel,gma"),
75 	COMPAT(AMS_AS3722, "ams,as3722"),
76 	COMPAT(INTEL_ICH_SPI, "intel,ich-spi"),
77 	COMPAT(INTEL_QRK_MRC, "intel,quark-mrc"),
78 	COMPAT(INTEL_X86_PINCTRL, "intel,x86-pinctrl"),
79 	COMPAT(SOCIONEXT_XHCI, "socionext,uniphier-xhci"),
80 	COMPAT(COMPAT_INTEL_PCH, "intel,bd82x6x"),
81 	COMPAT(COMPAT_INTEL_IRQ_ROUTER, "intel,irq-router"),
82 };
83 
84 const char *fdtdec_get_compatible(enum fdt_compat_id id)
85 {
86 	/* We allow reading of the 'unknown' ID for testing purposes */
87 	assert(id >= 0 && id < COMPAT_COUNT);
88 	return compat_names[id];
89 }
90 
91 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
92 		const char *prop_name, fdt_size_t *sizep)
93 {
94 	const fdt_addr_t *cell;
95 	int len;
96 
97 	debug("%s: %s: ", __func__, prop_name);
98 	cell = fdt_getprop(blob, node, prop_name, &len);
99 	if (cell && ((!sizep && len == sizeof(fdt_addr_t)) ||
100 		     len == sizeof(fdt_addr_t) * 2)) {
101 		fdt_addr_t addr = fdt_addr_to_cpu(*cell);
102 		if (sizep) {
103 			const fdt_size_t *size;
104 
105 			size = (fdt_size_t *)((char *)cell +
106 					sizeof(fdt_addr_t));
107 			*sizep = fdt_size_to_cpu(*size);
108 			debug("addr=%08lx, size=%08x\n",
109 			      (ulong)addr, *sizep);
110 		} else {
111 			debug("%08lx\n", (ulong)addr);
112 		}
113 		return addr;
114 	}
115 	debug("(not found)\n");
116 	return FDT_ADDR_T_NONE;
117 }
118 
119 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
120 		const char *prop_name)
121 {
122 	return fdtdec_get_addr_size(blob, node, prop_name, NULL);
123 }
124 
125 #ifdef CONFIG_PCI
126 int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
127 		const char *prop_name, struct fdt_pci_addr *addr)
128 {
129 	const u32 *cell;
130 	int len;
131 	int ret = -ENOENT;
132 
133 	debug("%s: %s: ", __func__, prop_name);
134 
135 	/*
136 	 * If we follow the pci bus bindings strictly, we should check
137 	 * the value of the node's parent node's #address-cells and
138 	 * #size-cells. They need to be 3 and 2 accordingly. However,
139 	 * for simplicity we skip the check here.
140 	 */
141 	cell = fdt_getprop(blob, node, prop_name, &len);
142 	if (!cell)
143 		goto fail;
144 
145 	if ((len % FDT_PCI_REG_SIZE) == 0) {
146 		int num = len / FDT_PCI_REG_SIZE;
147 		int i;
148 
149 		for (i = 0; i < num; i++) {
150 			debug("pci address #%d: %08lx %08lx %08lx\n", i,
151 			      (ulong)fdt_addr_to_cpu(cell[0]),
152 			      (ulong)fdt_addr_to_cpu(cell[1]),
153 			      (ulong)fdt_addr_to_cpu(cell[2]));
154 			if ((fdt_addr_to_cpu(*cell) & type) == type) {
155 				addr->phys_hi = fdt_addr_to_cpu(cell[0]);
156 				addr->phys_mid = fdt_addr_to_cpu(cell[1]);
157 				addr->phys_lo = fdt_addr_to_cpu(cell[2]);
158 				break;
159 			} else {
160 				cell += (FDT_PCI_ADDR_CELLS +
161 					 FDT_PCI_SIZE_CELLS);
162 			}
163 		}
164 
165 		if (i == num) {
166 			ret = -ENXIO;
167 			goto fail;
168 		}
169 
170 		return 0;
171 	} else {
172 		ret = -EINVAL;
173 	}
174 
175 fail:
176 	debug("(not found)\n");
177 	return ret;
178 }
179 
180 int fdtdec_get_pci_vendev(const void *blob, int node, u16 *vendor, u16 *device)
181 {
182 	const char *list, *end;
183 	int len;
184 
185 	list = fdt_getprop(blob, node, "compatible", &len);
186 	if (!list)
187 		return -ENOENT;
188 
189 	end = list + len;
190 	while (list < end) {
191 		char *s;
192 
193 		len = strlen(list);
194 		if (len >= strlen("pciVVVV,DDDD")) {
195 			s = strstr(list, "pci");
196 
197 			/*
198 			 * check if the string is something like pciVVVV,DDDD.RR
199 			 * or just pciVVVV,DDDD
200 			 */
201 			if (s && s[7] == ',' &&
202 			    (s[12] == '.' || s[12] == 0)) {
203 				s += 3;
204 				*vendor = simple_strtol(s, NULL, 16);
205 
206 				s += 5;
207 				*device = simple_strtol(s, NULL, 16);
208 
209 				return 0;
210 			}
211 		} else {
212 			list += (len + 1);
213 		}
214 	}
215 
216 	return -ENOENT;
217 }
218 
219 int fdtdec_get_pci_bdf(const void *blob, int node,
220 		struct fdt_pci_addr *addr, pci_dev_t *bdf)
221 {
222 	u16 dt_vendor, dt_device, vendor, device;
223 	int ret;
224 
225 	/* get vendor id & device id from the compatible string */
226 	ret = fdtdec_get_pci_vendev(blob, node, &dt_vendor, &dt_device);
227 	if (ret)
228 		return ret;
229 
230 	/* extract the bdf from fdt_pci_addr */
231 	*bdf = addr->phys_hi & 0xffff00;
232 
233 	/* read vendor id & device id based on bdf */
234 	pci_read_config_word(*bdf, PCI_VENDOR_ID, &vendor);
235 	pci_read_config_word(*bdf, PCI_DEVICE_ID, &device);
236 
237 	/*
238 	 * Note there are two places in the device tree to fully describe
239 	 * a pci device: one is via compatible string with a format of
240 	 * "pciVVVV,DDDD" and the other one is the bdf numbers encoded in
241 	 * the device node's reg address property. We read the vendor id
242 	 * and device id based on bdf and compare the values with the
243 	 * "VVVV,DDDD". If they are the same, then we are good to use bdf
244 	 * to read device's bar. But if they are different, we have to rely
245 	 * on the vendor id and device id extracted from the compatible
246 	 * string and locate the real bdf by pci_find_device(). This is
247 	 * because normally we may only know device's device number and
248 	 * function number when writing device tree. The bus number is
249 	 * dynamically assigned during the pci enumeration process.
250 	 */
251 	if ((dt_vendor != vendor) || (dt_device != device)) {
252 		*bdf = pci_find_device(dt_vendor, dt_device, 0);
253 		if (*bdf == -1)
254 			return -ENODEV;
255 	}
256 
257 	return 0;
258 }
259 
260 int fdtdec_get_pci_bar32(const void *blob, int node,
261 		struct fdt_pci_addr *addr, u32 *bar)
262 {
263 	pci_dev_t bdf;
264 	int barnum;
265 	int ret;
266 
267 	/* get pci devices's bdf */
268 	ret = fdtdec_get_pci_bdf(blob, node, addr, &bdf);
269 	if (ret)
270 		return ret;
271 
272 	/* extract the bar number from fdt_pci_addr */
273 	barnum = addr->phys_hi & 0xff;
274 	if ((barnum < PCI_BASE_ADDRESS_0) || (barnum > PCI_CARDBUS_CIS))
275 		return -EINVAL;
276 
277 	barnum = (barnum - PCI_BASE_ADDRESS_0) / 4;
278 	*bar = pci_read_bar32(pci_bus_to_hose(PCI_BUS(bdf)), bdf, barnum);
279 
280 	return 0;
281 }
282 #endif
283 
284 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
285 		uint64_t default_val)
286 {
287 	const uint64_t *cell64;
288 	int length;
289 
290 	cell64 = fdt_getprop(blob, node, prop_name, &length);
291 	if (!cell64 || length < sizeof(*cell64))
292 		return default_val;
293 
294 	return fdt64_to_cpu(*cell64);
295 }
296 
297 int fdtdec_get_is_enabled(const void *blob, int node)
298 {
299 	const char *cell;
300 
301 	/*
302 	 * It should say "okay", so only allow that. Some fdts use "ok" but
303 	 * this is a bug. Please fix your device tree source file. See here
304 	 * for discussion:
305 	 *
306 	 * http://www.mail-archive.com/u-boot@lists.denx.de/msg71598.html
307 	 */
308 	cell = fdt_getprop(blob, node, "status", NULL);
309 	if (cell)
310 		return 0 == strcmp(cell, "okay");
311 	return 1;
312 }
313 
314 enum fdt_compat_id fdtdec_lookup(const void *blob, int node)
315 {
316 	enum fdt_compat_id id;
317 
318 	/* Search our drivers */
319 	for (id = COMPAT_UNKNOWN; id < COMPAT_COUNT; id++)
320 		if (0 == fdt_node_check_compatible(blob, node,
321 				compat_names[id]))
322 			return id;
323 	return COMPAT_UNKNOWN;
324 }
325 
326 int fdtdec_next_compatible(const void *blob, int node,
327 		enum fdt_compat_id id)
328 {
329 	return fdt_node_offset_by_compatible(blob, node, compat_names[id]);
330 }
331 
332 int fdtdec_next_compatible_subnode(const void *blob, int node,
333 		enum fdt_compat_id id, int *depthp)
334 {
335 	do {
336 		node = fdt_next_node(blob, node, depthp);
337 	} while (*depthp > 1);
338 
339 	/* If this is a direct subnode, and compatible, return it */
340 	if (*depthp == 1 && 0 == fdt_node_check_compatible(
341 						blob, node, compat_names[id]))
342 		return node;
343 
344 	return -FDT_ERR_NOTFOUND;
345 }
346 
347 int fdtdec_next_alias(const void *blob, const char *name,
348 		enum fdt_compat_id id, int *upto)
349 {
350 #define MAX_STR_LEN 20
351 	char str[MAX_STR_LEN + 20];
352 	int node, err;
353 
354 	/* snprintf() is not available */
355 	assert(strlen(name) < MAX_STR_LEN);
356 	sprintf(str, "%.*s%d", MAX_STR_LEN, name, *upto);
357 	node = fdt_path_offset(blob, str);
358 	if (node < 0)
359 		return node;
360 	err = fdt_node_check_compatible(blob, node, compat_names[id]);
361 	if (err < 0)
362 		return err;
363 	if (err)
364 		return -FDT_ERR_NOTFOUND;
365 	(*upto)++;
366 	return node;
367 }
368 
369 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
370 			enum fdt_compat_id id, int *node_list, int maxcount)
371 {
372 	memset(node_list, '\0', sizeof(*node_list) * maxcount);
373 
374 	return fdtdec_add_aliases_for_id(blob, name, id, node_list, maxcount);
375 }
376 
377 /* TODO: Can we tighten this code up a little? */
378 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
379 			enum fdt_compat_id id, int *node_list, int maxcount)
380 {
381 	int name_len = strlen(name);
382 	int nodes[maxcount];
383 	int num_found = 0;
384 	int offset, node;
385 	int alias_node;
386 	int count;
387 	int i, j;
388 
389 	/* find the alias node if present */
390 	alias_node = fdt_path_offset(blob, "/aliases");
391 
392 	/*
393 	 * start with nothing, and we can assume that the root node can't
394 	 * match
395 	 */
396 	memset(nodes, '\0', sizeof(nodes));
397 
398 	/* First find all the compatible nodes */
399 	for (node = count = 0; node >= 0 && count < maxcount;) {
400 		node = fdtdec_next_compatible(blob, node, id);
401 		if (node >= 0)
402 			nodes[count++] = node;
403 	}
404 	if (node >= 0)
405 		debug("%s: warning: maxcount exceeded with alias '%s'\n",
406 		       __func__, name);
407 
408 	/* Now find all the aliases */
409 	for (offset = fdt_first_property_offset(blob, alias_node);
410 			offset > 0;
411 			offset = fdt_next_property_offset(blob, offset)) {
412 		const struct fdt_property *prop;
413 		const char *path;
414 		int number;
415 		int found;
416 
417 		node = 0;
418 		prop = fdt_get_property_by_offset(blob, offset, NULL);
419 		path = fdt_string(blob, fdt32_to_cpu(prop->nameoff));
420 		if (prop->len && 0 == strncmp(path, name, name_len))
421 			node = fdt_path_offset(blob, prop->data);
422 		if (node <= 0)
423 			continue;
424 
425 		/* Get the alias number */
426 		number = simple_strtoul(path + name_len, NULL, 10);
427 		if (number < 0 || number >= maxcount) {
428 			debug("%s: warning: alias '%s' is out of range\n",
429 			       __func__, path);
430 			continue;
431 		}
432 
433 		/* Make sure the node we found is actually in our list! */
434 		found = -1;
435 		for (j = 0; j < count; j++)
436 			if (nodes[j] == node) {
437 				found = j;
438 				break;
439 			}
440 
441 		if (found == -1) {
442 			debug("%s: warning: alias '%s' points to a node "
443 				"'%s' that is missing or is not compatible "
444 				" with '%s'\n", __func__, path,
445 				fdt_get_name(blob, node, NULL),
446 			       compat_names[id]);
447 			continue;
448 		}
449 
450 		/*
451 		 * Add this node to our list in the right place, and mark
452 		 * it as done.
453 		 */
454 		if (fdtdec_get_is_enabled(blob, node)) {
455 			if (node_list[number]) {
456 				debug("%s: warning: alias '%s' requires that "
457 				      "a node be placed in the list in a "
458 				      "position which is already filled by "
459 				      "node '%s'\n", __func__, path,
460 				      fdt_get_name(blob, node, NULL));
461 				continue;
462 			}
463 			node_list[number] = node;
464 			if (number >= num_found)
465 				num_found = number + 1;
466 		}
467 		nodes[found] = 0;
468 	}
469 
470 	/* Add any nodes not mentioned by an alias */
471 	for (i = j = 0; i < maxcount; i++) {
472 		if (!node_list[i]) {
473 			for (; j < maxcount; j++)
474 				if (nodes[j] &&
475 					fdtdec_get_is_enabled(blob, nodes[j]))
476 					break;
477 
478 			/* Have we run out of nodes to add? */
479 			if (j == maxcount)
480 				break;
481 
482 			assert(!node_list[i]);
483 			node_list[i] = nodes[j++];
484 			if (i >= num_found)
485 				num_found = i + 1;
486 		}
487 	}
488 
489 	return num_found;
490 }
491 
492 int fdtdec_get_alias_seq(const void *blob, const char *base, int offset,
493 			 int *seqp)
494 {
495 	int base_len = strlen(base);
496 	const char *find_name;
497 	int find_namelen;
498 	int prop_offset;
499 	int aliases;
500 
501 	find_name = fdt_get_name(blob, offset, &find_namelen);
502 	debug("Looking for '%s' at %d, name %s\n", base, offset, find_name);
503 
504 	aliases = fdt_path_offset(blob, "/aliases");
505 	for (prop_offset = fdt_first_property_offset(blob, aliases);
506 	     prop_offset > 0;
507 	     prop_offset = fdt_next_property_offset(blob, prop_offset)) {
508 		const char *prop;
509 		const char *name;
510 		const char *slash;
511 		const char *p;
512 		int len;
513 
514 		prop = fdt_getprop_by_offset(blob, prop_offset, &name, &len);
515 		debug("   - %s, %s\n", name, prop);
516 		if (len < find_namelen || *prop != '/' || prop[len - 1] ||
517 		    strncmp(name, base, base_len))
518 			continue;
519 
520 		slash = strrchr(prop, '/');
521 		if (strcmp(slash + 1, find_name))
522 			continue;
523 		for (p = name + strlen(name) - 1; p > name; p--) {
524 			if (!isdigit(*p)) {
525 				*seqp = simple_strtoul(p + 1, NULL, 10);
526 				debug("Found seq %d\n", *seqp);
527 				return 0;
528 			}
529 		}
530 	}
531 
532 	debug("Not found\n");
533 	return -ENOENT;
534 }
535 
536 int fdtdec_get_chosen_node(const void *blob, const char *name)
537 {
538 	const char *prop;
539 	int chosen_node;
540 	int len;
541 
542 	if (!blob)
543 		return -FDT_ERR_NOTFOUND;
544 	chosen_node = fdt_path_offset(blob, "/chosen");
545 	prop = fdt_getprop(blob, chosen_node, name, &len);
546 	if (!prop)
547 		return -FDT_ERR_NOTFOUND;
548 	return fdt_path_offset(blob, prop);
549 }
550 
551 int fdtdec_check_fdt(void)
552 {
553 	/*
554 	 * We must have an FDT, but we cannot panic() yet since the console
555 	 * is not ready. So for now, just assert(). Boards which need an early
556 	 * FDT (prior to console ready) will need to make their own
557 	 * arrangements and do their own checks.
558 	 */
559 	assert(!fdtdec_prepare_fdt());
560 	return 0;
561 }
562 
563 /*
564  * This function is a little odd in that it accesses global data. At some
565  * point if the architecture board.c files merge this will make more sense.
566  * Even now, it is common code.
567  */
568 int fdtdec_prepare_fdt(void)
569 {
570 	if (!gd->fdt_blob || ((uintptr_t)gd->fdt_blob & 3) ||
571 	    fdt_check_header(gd->fdt_blob)) {
572 #ifdef CONFIG_SPL_BUILD
573 		puts("Missing DTB\n");
574 #else
575 		puts("No valid device tree binary found - please append one to U-Boot binary, use u-boot-dtb.bin or define CONFIG_OF_EMBED. For sandbox, use -d <file.dtb>\n");
576 #endif
577 		return -1;
578 	}
579 	return 0;
580 }
581 
582 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name)
583 {
584 	const u32 *phandle;
585 	int lookup;
586 
587 	debug("%s: %s\n", __func__, prop_name);
588 	phandle = fdt_getprop(blob, node, prop_name, NULL);
589 	if (!phandle)
590 		return -FDT_ERR_NOTFOUND;
591 
592 	lookup = fdt_node_offset_by_phandle(blob, fdt32_to_cpu(*phandle));
593 	return lookup;
594 }
595 
596 /**
597  * Look up a property in a node and check that it has a minimum length.
598  *
599  * @param blob		FDT blob
600  * @param node		node to examine
601  * @param prop_name	name of property to find
602  * @param min_len	minimum property length in bytes
603  * @param err		0 if ok, or -FDT_ERR_NOTFOUND if the property is not
604 			found, or -FDT_ERR_BADLAYOUT if not enough data
605  * @return pointer to cell, which is only valid if err == 0
606  */
607 static const void *get_prop_check_min_len(const void *blob, int node,
608 		const char *prop_name, int min_len, int *err)
609 {
610 	const void *cell;
611 	int len;
612 
613 	debug("%s: %s\n", __func__, prop_name);
614 	cell = fdt_getprop(blob, node, prop_name, &len);
615 	if (!cell)
616 		*err = -FDT_ERR_NOTFOUND;
617 	else if (len < min_len)
618 		*err = -FDT_ERR_BADLAYOUT;
619 	else
620 		*err = 0;
621 	return cell;
622 }
623 
624 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
625 		u32 *array, int count)
626 {
627 	const u32 *cell;
628 	int i, err = 0;
629 
630 	debug("%s: %s\n", __func__, prop_name);
631 	cell = get_prop_check_min_len(blob, node, prop_name,
632 				      sizeof(u32) * count, &err);
633 	if (!err) {
634 		for (i = 0; i < count; i++)
635 			array[i] = fdt32_to_cpu(cell[i]);
636 	}
637 	return err;
638 }
639 
640 int fdtdec_get_int_array_count(const void *blob, int node,
641 			       const char *prop_name, u32 *array, int count)
642 {
643 	const u32 *cell;
644 	int len, elems;
645 	int i;
646 
647 	debug("%s: %s\n", __func__, prop_name);
648 	cell = fdt_getprop(blob, node, prop_name, &len);
649 	if (!cell)
650 		return -FDT_ERR_NOTFOUND;
651 	elems = len / sizeof(u32);
652 	if (count > elems)
653 		count = elems;
654 	for (i = 0; i < count; i++)
655 		array[i] = fdt32_to_cpu(cell[i]);
656 
657 	return count;
658 }
659 
660 const u32 *fdtdec_locate_array(const void *blob, int node,
661 			       const char *prop_name, int count)
662 {
663 	const u32 *cell;
664 	int err;
665 
666 	cell = get_prop_check_min_len(blob, node, prop_name,
667 				      sizeof(u32) * count, &err);
668 	return err ? NULL : cell;
669 }
670 
671 int fdtdec_get_bool(const void *blob, int node, const char *prop_name)
672 {
673 	const s32 *cell;
674 	int len;
675 
676 	debug("%s: %s\n", __func__, prop_name);
677 	cell = fdt_getprop(blob, node, prop_name, &len);
678 	return cell != NULL;
679 }
680 
681 int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
682 				   const char *list_name,
683 				   const char *cells_name,
684 				   int cell_count, int index,
685 				   struct fdtdec_phandle_args *out_args)
686 {
687 	const __be32 *list, *list_end;
688 	int rc = 0, size, cur_index = 0;
689 	uint32_t count = 0;
690 	int node = -1;
691 	int phandle;
692 
693 	/* Retrieve the phandle list property */
694 	list = fdt_getprop(blob, src_node, list_name, &size);
695 	if (!list)
696 		return -ENOENT;
697 	list_end = list + size / sizeof(*list);
698 
699 	/* Loop over the phandles until all the requested entry is found */
700 	while (list < list_end) {
701 		rc = -EINVAL;
702 		count = 0;
703 
704 		/*
705 		 * If phandle is 0, then it is an empty entry with no
706 		 * arguments.  Skip forward to the next entry.
707 		 */
708 		phandle = be32_to_cpup(list++);
709 		if (phandle) {
710 			/*
711 			 * Find the provider node and parse the #*-cells
712 			 * property to determine the argument length.
713 			 *
714 			 * This is not needed if the cell count is hard-coded
715 			 * (i.e. cells_name not set, but cell_count is set),
716 			 * except when we're going to return the found node
717 			 * below.
718 			 */
719 			if (cells_name || cur_index == index) {
720 				node = fdt_node_offset_by_phandle(blob,
721 								  phandle);
722 				if (!node) {
723 					debug("%s: could not find phandle\n",
724 					      fdt_get_name(blob, src_node,
725 							   NULL));
726 					goto err;
727 				}
728 			}
729 
730 			if (cells_name) {
731 				count = fdtdec_get_int(blob, node, cells_name,
732 						       -1);
733 				if (count == -1) {
734 					debug("%s: could not get %s for %s\n",
735 					      fdt_get_name(blob, src_node,
736 							   NULL),
737 					      cells_name,
738 					      fdt_get_name(blob, node,
739 							   NULL));
740 					goto err;
741 				}
742 			} else {
743 				count = cell_count;
744 			}
745 
746 			/*
747 			 * Make sure that the arguments actually fit in the
748 			 * remaining property data length
749 			 */
750 			if (list + count > list_end) {
751 				debug("%s: arguments longer than property\n",
752 				      fdt_get_name(blob, src_node, NULL));
753 				goto err;
754 			}
755 		}
756 
757 		/*
758 		 * All of the error cases above bail out of the loop, so at
759 		 * this point, the parsing is successful. If the requested
760 		 * index matches, then fill the out_args structure and return,
761 		 * or return -ENOENT for an empty entry.
762 		 */
763 		rc = -ENOENT;
764 		if (cur_index == index) {
765 			if (!phandle)
766 				goto err;
767 
768 			if (out_args) {
769 				int i;
770 
771 				if (count > MAX_PHANDLE_ARGS) {
772 					debug("%s: too many arguments %d\n",
773 					      fdt_get_name(blob, src_node,
774 							   NULL), count);
775 					count = MAX_PHANDLE_ARGS;
776 				}
777 				out_args->node = node;
778 				out_args->args_count = count;
779 				for (i = 0; i < count; i++) {
780 					out_args->args[i] =
781 							be32_to_cpup(list++);
782 				}
783 			}
784 
785 			/* Found it! return success */
786 			return 0;
787 		}
788 
789 		node = -1;
790 		list += count;
791 		cur_index++;
792 	}
793 
794 	/*
795 	 * Result will be one of:
796 	 * -ENOENT : index is for empty phandle
797 	 * -EINVAL : parsing error on data
798 	 * [1..n]  : Number of phandle (count mode; when index = -1)
799 	 */
800 	rc = index < 0 ? cur_index : -ENOENT;
801  err:
802 	return rc;
803 }
804 
805 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
806 		u8 *array, int count)
807 {
808 	const u8 *cell;
809 	int err;
810 
811 	cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
812 	if (!err)
813 		memcpy(array, cell, count);
814 	return err;
815 }
816 
817 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
818 			     const char *prop_name, int count)
819 {
820 	const u8 *cell;
821 	int err;
822 
823 	cell = get_prop_check_min_len(blob, node, prop_name, count, &err);
824 	if (err)
825 		return NULL;
826 	return cell;
827 }
828 
829 int fdtdec_get_config_int(const void *blob, const char *prop_name,
830 		int default_val)
831 {
832 	int config_node;
833 
834 	debug("%s: %s\n", __func__, prop_name);
835 	config_node = fdt_path_offset(blob, "/config");
836 	if (config_node < 0)
837 		return default_val;
838 	return fdtdec_get_int(blob, config_node, prop_name, default_val);
839 }
840 
841 int fdtdec_get_config_bool(const void *blob, const char *prop_name)
842 {
843 	int config_node;
844 	const void *prop;
845 
846 	debug("%s: %s\n", __func__, prop_name);
847 	config_node = fdt_path_offset(blob, "/config");
848 	if (config_node < 0)
849 		return 0;
850 	prop = fdt_get_property(blob, config_node, prop_name, NULL);
851 
852 	return prop != NULL;
853 }
854 
855 char *fdtdec_get_config_string(const void *blob, const char *prop_name)
856 {
857 	const char *nodep;
858 	int nodeoffset;
859 	int len;
860 
861 	debug("%s: %s\n", __func__, prop_name);
862 	nodeoffset = fdt_path_offset(blob, "/config");
863 	if (nodeoffset < 0)
864 		return NULL;
865 
866 	nodep = fdt_getprop(blob, nodeoffset, prop_name, &len);
867 	if (!nodep)
868 		return NULL;
869 
870 	return (char *)nodep;
871 }
872 
873 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
874 			 fdt_addr_t *basep, fdt_size_t *sizep)
875 {
876 	const fdt_addr_t *cell;
877 	int len;
878 
879 	debug("%s: %s: %s\n", __func__, fdt_get_name(blob, node, NULL),
880 	      prop_name);
881 	cell = fdt_getprop(blob, node, prop_name, &len);
882 	if (!cell || (len < sizeof(fdt_addr_t) * 2)) {
883 		debug("cell=%p, len=%d\n", cell, len);
884 		return -1;
885 	}
886 
887 	*basep = fdt_addr_to_cpu(*cell);
888 	*sizep = fdt_size_to_cpu(cell[1]);
889 	debug("%s: base=%08lx, size=%lx\n", __func__, (ulong)*basep,
890 	      (ulong)*sizep);
891 
892 	return 0;
893 }
894 
895 /**
896  * Read a flash entry from the fdt
897  *
898  * @param blob		FDT blob
899  * @param node		Offset of node to read
900  * @param name		Name of node being read
901  * @param entry		Place to put offset and size of this node
902  * @return 0 if ok, -ve on error
903  */
904 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
905 			   struct fmap_entry *entry)
906 {
907 	const char *prop;
908 	u32 reg[2];
909 
910 	if (fdtdec_get_int_array(blob, node, "reg", reg, 2)) {
911 		debug("Node '%s' has bad/missing 'reg' property\n", name);
912 		return -FDT_ERR_NOTFOUND;
913 	}
914 	entry->offset = reg[0];
915 	entry->length = reg[1];
916 	entry->used = fdtdec_get_int(blob, node, "used", entry->length);
917 	prop = fdt_getprop(blob, node, "compress", NULL);
918 	entry->compress_algo = prop && !strcmp(prop, "lzo") ?
919 		FMAP_COMPRESS_LZO : FMAP_COMPRESS_NONE;
920 	prop = fdt_getprop(blob, node, "hash", &entry->hash_size);
921 	entry->hash_algo = prop ? FMAP_HASH_SHA256 : FMAP_HASH_NONE;
922 	entry->hash = (uint8_t *)prop;
923 
924 	return 0;
925 }
926 
927 u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells)
928 {
929 	u64 number = 0;
930 
931 	while (cells--)
932 		number = (number << 32) | fdt32_to_cpu(*ptr++);
933 
934 	return number;
935 }
936 
937 int fdt_get_resource(const void *fdt, int node, const char *property,
938 		     unsigned int index, struct fdt_resource *res)
939 {
940 	const fdt32_t *ptr, *end;
941 	int na, ns, len, parent;
942 	unsigned int i = 0;
943 
944 	parent = fdt_parent_offset(fdt, node);
945 	if (parent < 0)
946 		return parent;
947 
948 	na = fdt_address_cells(fdt, parent);
949 	ns = fdt_size_cells(fdt, parent);
950 
951 	ptr = fdt_getprop(fdt, node, property, &len);
952 	if (!ptr)
953 		return len;
954 
955 	end = ptr + len / sizeof(*ptr);
956 
957 	while (ptr + na + ns <= end) {
958 		if (i == index) {
959 			res->start = res->end = fdtdec_get_number(ptr, na);
960 			res->end += fdtdec_get_number(&ptr[na], ns) - 1;
961 			return 0;
962 		}
963 
964 		ptr += na + ns;
965 		i++;
966 	}
967 
968 	return -FDT_ERR_NOTFOUND;
969 }
970 
971 int fdt_get_named_resource(const void *fdt, int node, const char *property,
972 			   const char *prop_names, const char *name,
973 			   struct fdt_resource *res)
974 {
975 	int index;
976 
977 	index = fdt_find_string(fdt, node, prop_names, name);
978 	if (index < 0)
979 		return index;
980 
981 	return fdt_get_resource(fdt, node, property, index, res);
982 }
983 
984 int fdtdec_decode_memory_region(const void *blob, int config_node,
985 				const char *mem_type, const char *suffix,
986 				fdt_addr_t *basep, fdt_size_t *sizep)
987 {
988 	char prop_name[50];
989 	const char *mem;
990 	fdt_size_t size, offset_size;
991 	fdt_addr_t base, offset;
992 	int node;
993 
994 	if (config_node == -1) {
995 		config_node = fdt_path_offset(blob, "/config");
996 		if (config_node < 0) {
997 			debug("%s: Cannot find /config node\n", __func__);
998 			return -ENOENT;
999 		}
1000 	}
1001 	if (!suffix)
1002 		suffix = "";
1003 
1004 	snprintf(prop_name, sizeof(prop_name), "%s-memory%s", mem_type,
1005 		 suffix);
1006 	mem = fdt_getprop(blob, config_node, prop_name, NULL);
1007 	if (!mem) {
1008 		debug("%s: No memory type for '%s', using /memory\n", __func__,
1009 		      prop_name);
1010 		mem = "/memory";
1011 	}
1012 
1013 	node = fdt_path_offset(blob, mem);
1014 	if (node < 0) {
1015 		debug("%s: Failed to find node '%s': %s\n", __func__, mem,
1016 		      fdt_strerror(node));
1017 		return -ENOENT;
1018 	}
1019 
1020 	/*
1021 	 * Not strictly correct - the memory may have multiple banks. We just
1022 	 * use the first
1023 	 */
1024 	if (fdtdec_decode_region(blob, node, "reg", &base, &size)) {
1025 		debug("%s: Failed to decode memory region %s\n", __func__,
1026 		      mem);
1027 		return -EINVAL;
1028 	}
1029 
1030 	snprintf(prop_name, sizeof(prop_name), "%s-offset%s", mem_type,
1031 		 suffix);
1032 	if (fdtdec_decode_region(blob, config_node, prop_name, &offset,
1033 				 &offset_size)) {
1034 		debug("%s: Failed to decode memory region '%s'\n", __func__,
1035 		      prop_name);
1036 		return -EINVAL;
1037 	}
1038 
1039 	*basep = base + offset;
1040 	*sizep = offset_size;
1041 
1042 	return 0;
1043 }
1044 
1045 static int decode_timing_property(const void *blob, int node, const char *name,
1046 				  struct timing_entry *result)
1047 {
1048 	int length, ret = 0;
1049 	const u32 *prop;
1050 
1051 	prop = fdt_getprop(blob, node, name, &length);
1052 	if (!prop) {
1053 		debug("%s: could not find property %s\n",
1054 		      fdt_get_name(blob, node, NULL), name);
1055 		return length;
1056 	}
1057 
1058 	if (length == sizeof(u32)) {
1059 		result->typ = fdtdec_get_int(blob, node, name, 0);
1060 		result->min = result->typ;
1061 		result->max = result->typ;
1062 	} else {
1063 		ret = fdtdec_get_int_array(blob, node, name, &result->min, 3);
1064 	}
1065 
1066 	return ret;
1067 }
1068 
1069 int fdtdec_decode_display_timing(const void *blob, int parent, int index,
1070 				 struct display_timing *dt)
1071 {
1072 	int i, node, timings_node;
1073 	u32 val = 0;
1074 	int ret = 0;
1075 
1076 	timings_node = fdt_subnode_offset(blob, parent, "display-timings");
1077 	if (timings_node < 0)
1078 		return timings_node;
1079 
1080 	for (i = 0, node = fdt_first_subnode(blob, timings_node);
1081 	     node > 0 && i != index;
1082 	     node = fdt_next_subnode(blob, node))
1083 		i++;
1084 
1085 	if (node < 0)
1086 		return node;
1087 
1088 	memset(dt, 0, sizeof(*dt));
1089 
1090 	ret |= decode_timing_property(blob, node, "hback-porch",
1091 				      &dt->hback_porch);
1092 	ret |= decode_timing_property(blob, node, "hfront-porch",
1093 				      &dt->hfront_porch);
1094 	ret |= decode_timing_property(blob, node, "hactive", &dt->hactive);
1095 	ret |= decode_timing_property(blob, node, "hsync-len", &dt->hsync_len);
1096 	ret |= decode_timing_property(blob, node, "vback-porch",
1097 				      &dt->vback_porch);
1098 	ret |= decode_timing_property(blob, node, "vfront-porch",
1099 				      &dt->vfront_porch);
1100 	ret |= decode_timing_property(blob, node, "vactive", &dt->vactive);
1101 	ret |= decode_timing_property(blob, node, "vsync-len", &dt->vsync_len);
1102 	ret |= decode_timing_property(blob, node, "clock-frequency",
1103 				      &dt->pixelclock);
1104 
1105 	dt->flags = 0;
1106 	val = fdtdec_get_int(blob, node, "vsync-active", -1);
1107 	if (val != -1) {
1108 		dt->flags |= val ? DISPLAY_FLAGS_VSYNC_HIGH :
1109 				DISPLAY_FLAGS_VSYNC_LOW;
1110 	}
1111 	val = fdtdec_get_int(blob, node, "hsync-active", -1);
1112 	if (val != -1) {
1113 		dt->flags |= val ? DISPLAY_FLAGS_HSYNC_HIGH :
1114 				DISPLAY_FLAGS_HSYNC_LOW;
1115 	}
1116 	val = fdtdec_get_int(blob, node, "de-active", -1);
1117 	if (val != -1) {
1118 		dt->flags |= val ? DISPLAY_FLAGS_DE_HIGH :
1119 				DISPLAY_FLAGS_DE_LOW;
1120 	}
1121 	val = fdtdec_get_int(blob, node, "pixelclk-active", -1);
1122 	if (val != -1) {
1123 		dt->flags |= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE :
1124 				DISPLAY_FLAGS_PIXDATA_NEGEDGE;
1125 	}
1126 
1127 	if (fdtdec_get_bool(blob, node, "interlaced"))
1128 		dt->flags |= DISPLAY_FLAGS_INTERLACED;
1129 	if (fdtdec_get_bool(blob, node, "doublescan"))
1130 		dt->flags |= DISPLAY_FLAGS_DOUBLESCAN;
1131 	if (fdtdec_get_bool(blob, node, "doubleclk"))
1132 		dt->flags |= DISPLAY_FLAGS_DOUBLECLK;
1133 
1134 	return 0;
1135 }
1136 
1137 int fdtdec_setup(void)
1138 {
1139 #ifdef CONFIG_OF_CONTROL
1140 # ifdef CONFIG_OF_EMBED
1141 	/* Get a pointer to the FDT */
1142 	gd->fdt_blob = __dtb_dt_begin;
1143 # elif defined CONFIG_OF_SEPARATE
1144 #  ifdef CONFIG_SPL_BUILD
1145 	/* FDT is at end of BSS */
1146 	gd->fdt_blob = (ulong *)&__bss_end;
1147 #  else
1148 	/* FDT is at end of image */
1149 	gd->fdt_blob = (ulong *)&_end;
1150 #endif
1151 # elif defined(CONFIG_OF_HOSTFILE)
1152 	if (sandbox_read_fdt_from_file()) {
1153 		puts("Failed to read control FDT\n");
1154 		return -1;
1155 	}
1156 # endif
1157 # ifndef CONFIG_SPL_BUILD
1158 	/* Allow the early environment to override the fdt address */
1159 	gd->fdt_blob = (void *)getenv_ulong("fdtcontroladdr", 16,
1160 						(uintptr_t)gd->fdt_blob);
1161 # endif
1162 #endif
1163 	return fdtdec_prepare_fdt();
1164 }
1165 
1166 #endif /* !USE_HOSTCC */
1167