xref: /openbmc/u-boot/include/fdtdec.h (revision 2a9ae6e02f190e8c83450aab9099a9fb5ec48cc9)
1 /*
2  * Copyright (c) 2011 The Chromium OS Authors.
3  * SPDX-License-Identifier:	GPL-2.0+
4  */
5 
6 #ifndef __fdtdec_h
7 #define __fdtdec_h
8 
9 /*
10  * This file contains convenience functions for decoding useful and
11  * enlightening information from FDTs. It is intended to be used by device
12  * drivers and board-specific code within U-Boot. It aims to reduce the
13  * amount of FDT munging required within U-Boot itself, so that driver code
14  * changes to support FDT are minimized.
15  */
16 
17 #include <libfdt.h>
18 
19 /*
20  * A typedef for a physical address. Note that fdt data is always big
21  * endian even on a litle endian machine.
22  */
23 #ifdef CONFIG_PHYS_64BIT
24 typedef u64 fdt_addr_t;
25 typedef u64 fdt_size_t;
26 #define FDT_ADDR_T_NONE (-1ULL)
27 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
28 #define fdt_size_to_cpu(reg) be64_to_cpu(reg)
29 #else
30 typedef u32 fdt_addr_t;
31 typedef u32 fdt_size_t;
32 #define FDT_ADDR_T_NONE (-1U)
33 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
34 #define fdt_size_to_cpu(reg) be32_to_cpu(reg)
35 #endif
36 
37 /* Information obtained about memory from the FDT */
38 struct fdt_memory {
39 	fdt_addr_t start;
40 	fdt_addr_t end;
41 };
42 
43 /**
44  * Compat types that we know about and for which we might have drivers.
45  * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
46  * within drivers.
47  */
48 enum fdt_compat_id {
49 	COMPAT_UNKNOWN,
50 	COMPAT_NVIDIA_TEGRA20_USB,	/* Tegra20 USB port */
51 	COMPAT_NVIDIA_TEGRA30_USB,	/* Tegra30 USB port */
52 	COMPAT_NVIDIA_TEGRA114_USB,	/* Tegra114 USB port */
53 	COMPAT_NVIDIA_TEGRA114_I2C,	/* Tegra114 I2C w/single clock source */
54 	COMPAT_NVIDIA_TEGRA20_I2C,	/* Tegra20 i2c */
55 	COMPAT_NVIDIA_TEGRA20_DVC,	/* Tegra20 dvc (really just i2c) */
56 	COMPAT_NVIDIA_TEGRA20_EMC,	/* Tegra20 memory controller */
57 	COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
58 	COMPAT_NVIDIA_TEGRA20_KBC,	/* Tegra20 Keyboard */
59 	COMPAT_NVIDIA_TEGRA20_NAND,	/* Tegra2 NAND controller */
60 	COMPAT_NVIDIA_TEGRA20_PWM,	/* Tegra 2 PWM controller */
61 	COMPAT_NVIDIA_TEGRA20_DC,	/* Tegra 2 Display controller */
62 	COMPAT_NVIDIA_TEGRA124_SDMMC,	/* Tegra124 SDMMC controller */
63 	COMPAT_NVIDIA_TEGRA30_SDMMC,	/* Tegra30 SDMMC controller */
64 	COMPAT_NVIDIA_TEGRA20_SDMMC,	/* Tegra20 SDMMC controller */
65 	COMPAT_NVIDIA_TEGRA20_SFLASH,	/* Tegra 2 SPI flash controller */
66 	COMPAT_NVIDIA_TEGRA20_SLINK,	/* Tegra 2 SPI SLINK controller */
67 	COMPAT_NVIDIA_TEGRA114_SPI,	/* Tegra 114 SPI controller */
68 	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
69 	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
70 	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */
71 	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
72 	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */
73 	COMPAT_SAMSUNG_EXYNOS_SPI,	/* Exynos SPI */
74 	COMPAT_GOOGLE_CROS_EC,		/* Google CROS_EC Protocol */
75 	COMPAT_GOOGLE_CROS_EC_KEYB,	/* Google CROS_EC Keyboard */
76 	COMPAT_SAMSUNG_EXYNOS_EHCI,	/* Exynos EHCI controller */
77 	COMPAT_SAMSUNG_EXYNOS5_XHCI,	/* Exynos5 XHCI controller */
78 	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */
79 	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
80 	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */
81 	COMPAT_SAMSUNG_EXYNOS_FIMD,	/* Exynos Display controller */
82 	COMPAT_SAMSUNG_EXYNOS_MIPI_DSI,	/* Exynos mipi dsi */
83 	COMPAT_SAMSUNG_EXYNOS5_DP,	/* Exynos Display port controller */
84 	COMPAT_SAMSUNG_EXYNOS_DWMMC,	/* Exynos DWMMC controller */
85 	COMPAT_SAMSUNG_EXYNOS_MMC,	/* Exynos MMC controller */
86 	COMPAT_SAMSUNG_EXYNOS_SERIAL,	/* Exynos UART */
87 	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */
88 	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */
89 	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */
90 	COMPAT_INFINEON_SLB9635_TPM,	/* Infineon SLB9635 TPM */
91 	COMPAT_INFINEON_SLB9645_TPM,	/* Infineon SLB9645 TPM */
92 	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */
93 	COMPAT_SANDBOX_HOST_EMULATION,	/* Sandbox emulation of a function */
94 	COMPAT_SANDBOX_LCD_SDL,		/* Sandbox LCD emulation with SDL */
95 	COMPAT_TI_TPS65090,		/* Texas Instrument TPS65090 */
96 	COMPAT_NXP_PTN3460,		/* NXP PTN3460 DP/LVDS bridge */
97 
98 	COMPAT_COUNT,
99 };
100 
101 /* GPIOs are numbered from 0 */
102 enum {
103 	FDT_GPIO_NONE = -1U,	/* an invalid GPIO used to end our list */
104 
105 	FDT_GPIO_ACTIVE_LOW = 1 << 0,	/* input is active low (else high) */
106 };
107 
108 /* This is the state of a GPIO pin as defined by the fdt */
109 struct fdt_gpio_state {
110 	const char *name;	/* name of the fdt property defining this */
111 	uint gpio;		/* GPIO number, or FDT_GPIO_NONE if none */
112 	u8 flags;		/* FDT_GPIO_... flags */
113 };
114 
115 /* This tells us whether a fdt_gpio_state record is valid or not */
116 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
117 
118 /**
119  * Read the GPIO taking into account the polarity of the pin.
120  *
121  * @param gpio		pointer to the decoded gpio
122  * @return value of the gpio if successful, < 0 if unsuccessful
123  */
124 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
125 
126 /**
127  * Write the GPIO taking into account the polarity of the pin.
128  *
129  * @param gpio		pointer to the decoded gpio
130  * @return 0 if successful
131  */
132 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
133 
134 /**
135  * Find the next numbered alias for a peripheral. This is used to enumerate
136  * all the peripherals of a certain type.
137  *
138  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
139  * this function will return a pointer to the node the alias points to, and
140  * then update *upto to 1. Next time you call this function, the next node
141  * will be returned.
142  *
143  * All nodes returned will match the compatible ID, as it is assumed that
144  * all peripherals use the same driver.
145  *
146  * @param blob		FDT blob to use
147  * @param name		Root name of alias to search for
148  * @param id		Compatible ID to look for
149  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
150  */
151 int fdtdec_next_alias(const void *blob, const char *name,
152 		enum fdt_compat_id id, int *upto);
153 
154 /**
155  * Find the compatible ID for a given node.
156  *
157  * Generally each node has at least one compatible string attached to it.
158  * This function looks through our list of known compatible strings and
159  * returns the corresponding ID which matches the compatible string.
160  *
161  * @param blob		FDT blob to use
162  * @param node		Node containing compatible string to find
163  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
164  */
165 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
166 
167 /**
168  * Find the next compatible node for a peripheral.
169  *
170  * Do the first call with node = 0. This function will return a pointer to
171  * the next compatible node. Next time you call this function, pass the
172  * value returned, and the next node will be provided.
173  *
174  * @param blob		FDT blob to use
175  * @param node		Start node for search
176  * @param id		Compatible ID to look for (enum fdt_compat_id)
177  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
178  */
179 int fdtdec_next_compatible(const void *blob, int node,
180 		enum fdt_compat_id id);
181 
182 /**
183  * Find the next compatible subnode for a peripheral.
184  *
185  * Do the first call with node set to the parent and depth = 0. This
186  * function will return the offset of the next compatible node. Next time
187  * you call this function, pass the node value returned last time, with
188  * depth unchanged, and the next node will be provided.
189  *
190  * @param blob		FDT blob to use
191  * @param node		Start node for search
192  * @param id		Compatible ID to look for (enum fdt_compat_id)
193  * @param depthp	Current depth (set to 0 before first call)
194  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
195  */
196 int fdtdec_next_compatible_subnode(const void *blob, int node,
197 		enum fdt_compat_id id, int *depthp);
198 
199 /**
200  * Look up an address property in a node and return it as an address.
201  * The property must hold either one address with no trailing data or
202  * one address with a length. This is only tested on 32-bit machines.
203  *
204  * @param blob	FDT blob
205  * @param node	node to examine
206  * @param prop_name	name of property to find
207  * @return address, if found, or FDT_ADDR_T_NONE if not
208  */
209 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
210 		const char *prop_name);
211 
212 /**
213  * Look up an address property in a node and return it as an address.
214  * The property must hold one address with a length. This is only tested
215  * on 32-bit machines.
216  *
217  * @param blob	FDT blob
218  * @param node	node to examine
219  * @param prop_name	name of property to find
220  * @return address, if found, or FDT_ADDR_T_NONE if not
221  */
222 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
223 		const char *prop_name, fdt_size_t *sizep);
224 
225 /**
226  * Look up a 32-bit integer property in a node and return it. The property
227  * must have at least 4 bytes of data. The value of the first cell is
228  * returned.
229  *
230  * @param blob	FDT blob
231  * @param node	node to examine
232  * @param prop_name	name of property to find
233  * @param default_val	default value to return if the property is not found
234  * @return integer value, if found, or default_val if not
235  */
236 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
237 		s32 default_val);
238 
239 /**
240  * Look up a 64-bit integer property in a node and return it. The property
241  * must have at least 8 bytes of data (2 cells). The first two cells are
242  * concatenated to form a 8 bytes value, where the first cell is top half and
243  * the second cell is bottom half.
244  *
245  * @param blob	FDT blob
246  * @param node	node to examine
247  * @param prop_name	name of property to find
248  * @param default_val	default value to return if the property is not found
249  * @return integer value, if found, or default_val if not
250  */
251 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
252 		uint64_t default_val);
253 
254 /**
255  * Checks whether a node is enabled.
256  * This looks for a 'status' property. If this exists, then returns 1 if
257  * the status is 'ok' and 0 otherwise. If there is no status property,
258  * it returns 1 on the assumption that anything mentioned should be enabled
259  * by default.
260  *
261  * @param blob	FDT blob
262  * @param node	node to examine
263  * @return integer value 0 (not enabled) or 1 (enabled)
264  */
265 int fdtdec_get_is_enabled(const void *blob, int node);
266 
267 /**
268  * Make sure we have a valid fdt available to control U-Boot.
269  *
270  * If not, a message is printed to the console if the console is ready.
271  *
272  * @return 0 if all ok, -1 if not
273  */
274 int fdtdec_prepare_fdt(void);
275 
276 /**
277  * Checks that we have a valid fdt available to control U-Boot.
278 
279  * However, if not then for the moment nothing is done, since this function
280  * is called too early to panic().
281  *
282  * @returns 0
283  */
284 int fdtdec_check_fdt(void);
285 
286 /**
287  * Find the nodes for a peripheral and return a list of them in the correct
288  * order. This is used to enumerate all the peripherals of a certain type.
289  *
290  * To use this, optionally set up a /aliases node with alias properties for
291  * a peripheral. For example, for usb you could have:
292  *
293  * aliases {
294  *		usb0 = "/ehci@c5008000";
295  *		usb1 = "/ehci@c5000000";
296  * };
297  *
298  * Pass "usb" as the name to this function and will return a list of two
299  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
300  *
301  * All nodes returned will match the compatible ID, as it is assumed that
302  * all peripherals use the same driver.
303  *
304  * If no alias node is found, then the node list will be returned in the
305  * order found in the fdt. If the aliases mention a node which doesn't
306  * exist, then this will be ignored. If nodes are found with no aliases,
307  * they will be added in any order.
308  *
309  * If there is a gap in the aliases, then this function return a 0 node at
310  * that position. The return value will also count these gaps.
311  *
312  * This function checks node properties and will not return nodes which are
313  * marked disabled (status = "disabled").
314  *
315  * @param blob		FDT blob to use
316  * @param name		Root name of alias to search for
317  * @param id		Compatible ID to look for
318  * @param node_list	Place to put list of found nodes
319  * @param maxcount	Maximum number of nodes to find
320  * @return number of nodes found on success, FTD_ERR_... on error
321  */
322 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
323 			enum fdt_compat_id id, int *node_list, int maxcount);
324 
325 /*
326  * This function is similar to fdtdec_find_aliases_for_id() except that it
327  * adds to the node_list that is passed in. Any 0 elements are considered
328  * available for allocation - others are considered already used and are
329  * skipped.
330  *
331  * You can use this by calling fdtdec_find_aliases_for_id() with an
332  * uninitialised array, then setting the elements that are returned to -1,
333  * say, then calling this function, perhaps with a different compat id.
334  * Any elements you get back that are >0 are new nodes added by the call
335  * to this function.
336  *
337  * Note that if you have some nodes with aliases and some without, you are
338  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
339  * one compat_id may fill in positions for which you have aliases defined
340  * for another compat_id. When you later call *this* function with the second
341  * compat_id, the alias positions may already be used. A debug warning may
342  * be generated in this case, but it is safest to define aliases for all
343  * nodes when you care about the ordering.
344  */
345 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
346 			enum fdt_compat_id id, int *node_list, int maxcount);
347 
348 /**
349  * Get the alias sequence number of a node
350  *
351  * This works out whether a node is pointed to by an alias, and if so, the
352  * sequence number of that alias. Aliases are of the form <base><num> where
353  * <num> is the sequence number. For example spi2 would be sequence number
354  * 2.
355  *
356  * @param blob		Device tree blob (if NULL, then error is returned)
357  * @param base		Base name for alias (before the underscore)
358  * @param node		Node to look up
359  * @param seqp		This is set to the sequence number if one is found,
360  *			but otherwise the value is left alone
361  * @return 0 if a sequence was found, -ve if not
362  */
363 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
364 			 int *seqp);
365 
366 /**
367  * Get the offset of the given alias node
368  *
369  * This looks up an alias in /aliases then finds the offset of that node.
370  *
371  * @param blob		Device tree blob (if NULL, then error is returned)
372  * @param name		Alias name, e.g. "console"
373  * @return Node offset referred to by that alias, or -ve FDT_ERR_...
374  */
375 int fdtdec_get_alias_node(const void *blob, const char *name);
376 
377 /**
378  * Get the offset of the given chosen node
379  *
380  * This looks up a property in /chosen containing the path to another node,
381  * then finds the offset of that node.
382  *
383  * @param blob		Device tree blob (if NULL, then error is returned)
384  * @param name		Property name, e.g. "stdout-path"
385  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
386  */
387 int fdtdec_get_chosen_node(const void *blob, const char *name);
388 
389 /*
390  * Get the name for a compatible ID
391  *
392  * @param id		Compatible ID to look for
393  * @return compatible string for that id
394  */
395 const char *fdtdec_get_compatible(enum fdt_compat_id id);
396 
397 /* Look up a phandle and follow it to its node. Then return the offset
398  * of that node.
399  *
400  * @param blob		FDT blob
401  * @param node		node to examine
402  * @param prop_name	name of property to find
403  * @return node offset if found, -ve error code on error
404  */
405 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
406 
407 /**
408  * Look up a property in a node and return its contents in an integer
409  * array of given length. The property must have at least enough data for
410  * the array (4*count bytes). It may have more, but this will be ignored.
411  *
412  * @param blob		FDT blob
413  * @param node		node to examine
414  * @param prop_name	name of property to find
415  * @param array		array to fill with data
416  * @param count		number of array elements
417  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
418  *		or -FDT_ERR_BADLAYOUT if not enough data
419  */
420 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
421 		u32 *array, int count);
422 
423 /**
424  * Look up a property in a node and return a pointer to its contents as a
425  * unsigned int array of given length. The property must have at least enough
426  * data for the array ('count' cells). It may have more, but this will be
427  * ignored. The data is not copied.
428  *
429  * Note that you must access elements of the array with fdt32_to_cpu(),
430  * since the elements will be big endian even on a little endian machine.
431  *
432  * @param blob		FDT blob
433  * @param node		node to examine
434  * @param prop_name	name of property to find
435  * @param count		number of array elements
436  * @return pointer to array if found, or NULL if the property is not
437  *		found or there is not enough data
438  */
439 const u32 *fdtdec_locate_array(const void *blob, int node,
440 			       const char *prop_name, int count);
441 
442 /**
443  * Look up a boolean property in a node and return it.
444  *
445  * A boolean properly is true if present in the device tree and false if not
446  * present, regardless of its value.
447  *
448  * @param blob	FDT blob
449  * @param node	node to examine
450  * @param prop_name	name of property to find
451  * @return 1 if the properly is present; 0 if it isn't present
452  */
453 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
454 
455 /**
456  * Decode a single GPIOs from an FDT.
457  *
458  * If the property is not found, then the GPIO structure will still be
459  * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
460  * provide optional GPIOs.
461  *
462  * @param blob		FDT blob to use
463  * @param node		Node to look at
464  * @param prop_name	Node property name
465  * @param gpio		gpio elements to fill from FDT
466  * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
467  */
468 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
469 		struct fdt_gpio_state *gpio);
470 
471 /**
472  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
473  * terminating item.
474  *
475  * @param blob         FDT blob to use
476  * @param node         Node to look at
477  * @param prop_name    Node property name
478  * @param gpio         Array of gpio elements to fill from FDT. This will be
479  *                     untouched if either 0 or an error is returned
480  * @param max_count    Maximum number of elements allowed
481  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
482  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
483  */
484 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
485 		struct fdt_gpio_state *gpio, int max_count);
486 
487 /**
488  * Set up a GPIO pin according to the provided gpio information. At present this
489  * just requests the GPIO.
490  *
491  * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
492  * deal with optional GPIOs.
493  *
494  * @param gpio		GPIO info to use for set up
495  * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
496  */
497 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
498 
499 /**
500  * Look in the FDT for a config item with the given name and return its value
501  * as a 32-bit integer. The property must have at least 4 bytes of data. The
502  * value of the first cell is returned.
503  *
504  * @param blob		FDT blob to use
505  * @param prop_name	Node property name
506  * @param default_val	default value to return if the property is not found
507  * @return integer value, if found, or default_val if not
508  */
509 int fdtdec_get_config_int(const void *blob, const char *prop_name,
510 		int default_val);
511 
512 /**
513  * Look in the FDT for a config item with the given name
514  * and return whether it exists.
515  *
516  * @param blob		FDT blob
517  * @param prop_name	property name to look up
518  * @return 1, if it exists, or 0 if not
519  */
520 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
521 
522 /**
523  * Look in the FDT for a config item with the given name and return its value
524  * as a string.
525  *
526  * @param blob          FDT blob
527  * @param prop_name     property name to look up
528  * @returns property string, NULL on error.
529  */
530 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
531 
532 /*
533  * Look up a property in a node and return its contents in a byte
534  * array of given length. The property must have at least enough data for
535  * the array (count bytes). It may have more, but this will be ignored.
536  *
537  * @param blob		FDT blob
538  * @param node		node to examine
539  * @param prop_name	name of property to find
540  * @param array		array to fill with data
541  * @param count		number of array elements
542  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
543  *		or -FDT_ERR_BADLAYOUT if not enough data
544  */
545 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
546 		u8 *array, int count);
547 
548 /**
549  * Look up a property in a node and return a pointer to its contents as a
550  * byte array of given length. The property must have at least enough data
551  * for the array (count bytes). It may have more, but this will be ignored.
552  * The data is not copied.
553  *
554  * @param blob		FDT blob
555  * @param node		node to examine
556  * @param prop_name	name of property to find
557  * @param count		number of array elements
558  * @return pointer to byte array if found, or NULL if the property is not
559  *		found or there is not enough data
560  */
561 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
562 			     const char *prop_name, int count);
563 
564 /**
565  * Look up a property in a node which contains a memory region address and
566  * size. Then return a pointer to this address.
567  *
568  * The property must hold one address with a length. This is only tested on
569  * 32-bit machines.
570  *
571  * @param blob		FDT blob
572  * @param node		node to examine
573  * @param prop_name	name of property to find
574  * @param ptrp		returns pointer to region, or NULL if no address
575  * @param size		returns size of region
576  * @return 0 if ok, -1 on error (propery not found)
577  */
578 int fdtdec_decode_region(const void *blob, int node,
579 		const char *prop_name, void **ptrp, size_t *size);
580 
581 /* A flash map entry, containing an offset and length */
582 struct fmap_entry {
583 	uint32_t offset;
584 	uint32_t length;
585 };
586 
587 /**
588  * Read a flash entry from the fdt
589  *
590  * @param blob		FDT blob
591  * @param node		Offset of node to read
592  * @param name		Name of node being read
593  * @param entry		Place to put offset and size of this node
594  * @return 0 if ok, -ve on error
595  */
596 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
597 			   struct fmap_entry *entry);
598 #endif
599