xref: /rk3399_rockchip-uboot/include/fdtdec.h (revision 79c7a90f6c642c27da3de5c134816be7f0405f1d)
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  * Information about a resource. start is the first address of the resource
45  * and end is the last address (inclusive). The length of the resource will
46  * be equal to: end - start + 1.
47  */
48 struct fdt_resource {
49 	fdt_addr_t start;
50 	fdt_addr_t end;
51 };
52 
53 /**
54  * Compute the size of a resource.
55  *
56  * @param res	the resource to operate on
57  * @return the size of the resource
58  */
59 static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
60 {
61 	return res->end - res->start + 1;
62 }
63 
64 /**
65  * Compat types that we know about and for which we might have drivers.
66  * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
67  * within drivers.
68  */
69 enum fdt_compat_id {
70 	COMPAT_UNKNOWN,
71 	COMPAT_NVIDIA_TEGRA20_USB,	/* Tegra20 USB port */
72 	COMPAT_NVIDIA_TEGRA30_USB,	/* Tegra30 USB port */
73 	COMPAT_NVIDIA_TEGRA114_USB,	/* Tegra114 USB port */
74 	COMPAT_NVIDIA_TEGRA114_I2C,	/* Tegra114 I2C w/single clock source */
75 	COMPAT_NVIDIA_TEGRA20_I2C,	/* Tegra20 i2c */
76 	COMPAT_NVIDIA_TEGRA20_DVC,	/* Tegra20 dvc (really just i2c) */
77 	COMPAT_NVIDIA_TEGRA20_EMC,	/* Tegra20 memory controller */
78 	COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
79 	COMPAT_NVIDIA_TEGRA20_KBC,	/* Tegra20 Keyboard */
80 	COMPAT_NVIDIA_TEGRA20_NAND,	/* Tegra2 NAND controller */
81 	COMPAT_NVIDIA_TEGRA20_PWM,	/* Tegra 2 PWM controller */
82 	COMPAT_NVIDIA_TEGRA20_DC,	/* Tegra 2 Display controller */
83 	COMPAT_NVIDIA_TEGRA124_SDMMC,	/* Tegra124 SDMMC controller */
84 	COMPAT_NVIDIA_TEGRA30_SDMMC,	/* Tegra30 SDMMC controller */
85 	COMPAT_NVIDIA_TEGRA20_SDMMC,	/* Tegra20 SDMMC controller */
86 	COMPAT_NVIDIA_TEGRA20_SFLASH,	/* Tegra 2 SPI flash controller */
87 	COMPAT_NVIDIA_TEGRA20_SLINK,	/* Tegra 2 SPI SLINK controller */
88 	COMPAT_NVIDIA_TEGRA114_SPI,	/* Tegra 114 SPI controller */
89 	COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
90 					/* Tegra124 XUSB pad controller */
91 	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
92 	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
93 	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */
94 	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
95 	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */
96 	COMPAT_SAMSUNG_EXYNOS_SPI,	/* Exynos SPI */
97 	COMPAT_GOOGLE_CROS_EC,		/* Google CROS_EC Protocol */
98 	COMPAT_GOOGLE_CROS_EC_KEYB,	/* Google CROS_EC Keyboard */
99 	COMPAT_SAMSUNG_EXYNOS_EHCI,	/* Exynos EHCI controller */
100 	COMPAT_SAMSUNG_EXYNOS5_XHCI,	/* Exynos5 XHCI controller */
101 	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */
102 	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
103 	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */
104 	COMPAT_SAMSUNG_EXYNOS_FIMD,	/* Exynos Display controller */
105 	COMPAT_SAMSUNG_EXYNOS_MIPI_DSI,	/* Exynos mipi dsi */
106 	COMPAT_SAMSUNG_EXYNOS5_DP,	/* Exynos Display port controller */
107 	COMPAT_SAMSUNG_EXYNOS_DWMMC,	/* Exynos DWMMC controller */
108 	COMPAT_SAMSUNG_EXYNOS_MMC,	/* Exynos MMC controller */
109 	COMPAT_SAMSUNG_EXYNOS_SERIAL,	/* Exynos UART */
110 	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */
111 	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */
112 	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */
113 	COMPAT_INFINEON_SLB9635_TPM,	/* Infineon SLB9635 TPM */
114 	COMPAT_INFINEON_SLB9645_TPM,	/* Infineon SLB9645 TPM */
115 	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */
116 	COMPAT_SANDBOX_HOST_EMULATION,	/* Sandbox emulation of a function */
117 	COMPAT_SANDBOX_LCD_SDL,		/* Sandbox LCD emulation with SDL */
118 	COMPAT_TI_TPS65090,		/* Texas Instrument TPS65090 */
119 	COMPAT_NXP_PTN3460,		/* NXP PTN3460 DP/LVDS bridge */
120 	COMPAT_SAMSUNG_EXYNOS_SYSMMU,	/* Exynos sysmmu */
121 	COMPAT_PARADE_PS8625,		/* Parade PS8622 EDP->LVDS bridge */
122 	COMPAT_INTEL_LPC,		/* Intel Low Pin Count I/F */
123 	COMPAT_INTEL_MICROCODE,		/* Intel microcode update */
124 	COMPAT_MEMORY_SPD,		/* Memory SPD information */
125 	COMPAT_INTEL_PANTHERPOINT_AHCI,	/* Intel Pantherpoint AHCI */
126 	COMPAT_INTEL_MODEL_206AX,	/* Intel Model 206AX CPU */
127 	COMPAT_INTEL_GMA,		/* Intel Graphics Media Accelerator */
128 	COMPAT_AMS_AS3722,		/* AMS AS3722 PMIC */
129 
130 	COMPAT_COUNT,
131 };
132 
133 /* GPIOs are numbered from 0 */
134 enum {
135 	FDT_GPIO_NONE = -1U,	/* an invalid GPIO used to end our list */
136 
137 	FDT_GPIO_ACTIVE_LOW = 1 << 0,	/* input is active low (else high) */
138 };
139 
140 /* This is the state of a GPIO pin as defined by the fdt */
141 struct fdt_gpio_state {
142 	const char *name;	/* name of the fdt property defining this */
143 	uint gpio;		/* GPIO number, or FDT_GPIO_NONE if none */
144 	u8 flags;		/* FDT_GPIO_... flags */
145 };
146 
147 /* This tells us whether a fdt_gpio_state record is valid or not */
148 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
149 
150 /**
151  * Read the GPIO taking into account the polarity of the pin.
152  *
153  * @param gpio		pointer to the decoded gpio
154  * @return value of the gpio if successful, < 0 if unsuccessful
155  */
156 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
157 
158 /**
159  * Write the GPIO taking into account the polarity of the pin.
160  *
161  * @param gpio		pointer to the decoded gpio
162  * @return 0 if successful
163  */
164 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
165 
166 /**
167  * Find the next numbered alias for a peripheral. This is used to enumerate
168  * all the peripherals of a certain type.
169  *
170  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
171  * this function will return a pointer to the node the alias points to, and
172  * then update *upto to 1. Next time you call this function, the next node
173  * will be returned.
174  *
175  * All nodes returned will match the compatible ID, as it is assumed that
176  * all peripherals use the same driver.
177  *
178  * @param blob		FDT blob to use
179  * @param name		Root name of alias to search for
180  * @param id		Compatible ID to look for
181  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
182  */
183 int fdtdec_next_alias(const void *blob, const char *name,
184 		enum fdt_compat_id id, int *upto);
185 
186 /**
187  * Find the compatible ID for a given node.
188  *
189  * Generally each node has at least one compatible string attached to it.
190  * This function looks through our list of known compatible strings and
191  * returns the corresponding ID which matches the compatible string.
192  *
193  * @param blob		FDT blob to use
194  * @param node		Node containing compatible string to find
195  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
196  */
197 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
198 
199 /**
200  * Find the next compatible node for a peripheral.
201  *
202  * Do the first call with node = 0. This function will return a pointer to
203  * the next compatible node. Next time you call this function, pass the
204  * value returned, and the next node will be provided.
205  *
206  * @param blob		FDT blob to use
207  * @param node		Start node for search
208  * @param id		Compatible ID to look for (enum fdt_compat_id)
209  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
210  */
211 int fdtdec_next_compatible(const void *blob, int node,
212 		enum fdt_compat_id id);
213 
214 /**
215  * Find the next compatible subnode for a peripheral.
216  *
217  * Do the first call with node set to the parent and depth = 0. This
218  * function will return the offset of the next compatible node. Next time
219  * you call this function, pass the node value returned last time, with
220  * depth unchanged, and the next node will be provided.
221  *
222  * @param blob		FDT blob to use
223  * @param node		Start node for search
224  * @param id		Compatible ID to look for (enum fdt_compat_id)
225  * @param depthp	Current depth (set to 0 before first call)
226  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
227  */
228 int fdtdec_next_compatible_subnode(const void *blob, int node,
229 		enum fdt_compat_id id, int *depthp);
230 
231 /**
232  * Look up an address property in a node and return it as an address.
233  * The property must hold either one address with no trailing data or
234  * one address with a length. This is only tested on 32-bit machines.
235  *
236  * @param blob	FDT blob
237  * @param node	node to examine
238  * @param prop_name	name of property to find
239  * @return address, if found, or FDT_ADDR_T_NONE if not
240  */
241 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
242 		const char *prop_name);
243 
244 /**
245  * Look up an address property in a node and return it as an address.
246  * The property must hold one address with a length. This is only tested
247  * on 32-bit machines.
248  *
249  * @param blob	FDT blob
250  * @param node	node to examine
251  * @param prop_name	name of property to find
252  * @return address, if found, or FDT_ADDR_T_NONE if not
253  */
254 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
255 		const char *prop_name, fdt_size_t *sizep);
256 
257 /**
258  * Look up a 32-bit integer property in a node and return it. The property
259  * must have at least 4 bytes of data. The value of the first cell is
260  * returned.
261  *
262  * @param blob	FDT blob
263  * @param node	node to examine
264  * @param prop_name	name of property to find
265  * @param default_val	default value to return if the property is not found
266  * @return integer value, if found, or default_val if not
267  */
268 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
269 		s32 default_val);
270 
271 /**
272  * Look up a 64-bit integer property in a node and return it. The property
273  * must have at least 8 bytes of data (2 cells). The first two cells are
274  * concatenated to form a 8 bytes value, where the first cell is top half and
275  * the second cell is bottom half.
276  *
277  * @param blob	FDT blob
278  * @param node	node to examine
279  * @param prop_name	name of property to find
280  * @param default_val	default value to return if the property is not found
281  * @return integer value, if found, or default_val if not
282  */
283 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
284 		uint64_t default_val);
285 
286 /**
287  * Checks whether a node is enabled.
288  * This looks for a 'status' property. If this exists, then returns 1 if
289  * the status is 'ok' and 0 otherwise. If there is no status property,
290  * it returns 1 on the assumption that anything mentioned should be enabled
291  * by default.
292  *
293  * @param blob	FDT blob
294  * @param node	node to examine
295  * @return integer value 0 (not enabled) or 1 (enabled)
296  */
297 int fdtdec_get_is_enabled(const void *blob, int node);
298 
299 /**
300  * Make sure we have a valid fdt available to control U-Boot.
301  *
302  * If not, a message is printed to the console if the console is ready.
303  *
304  * @return 0 if all ok, -1 if not
305  */
306 int fdtdec_prepare_fdt(void);
307 
308 /**
309  * Checks that we have a valid fdt available to control U-Boot.
310 
311  * However, if not then for the moment nothing is done, since this function
312  * is called too early to panic().
313  *
314  * @returns 0
315  */
316 int fdtdec_check_fdt(void);
317 
318 /**
319  * Find the nodes for a peripheral and return a list of them in the correct
320  * order. This is used to enumerate all the peripherals of a certain type.
321  *
322  * To use this, optionally set up a /aliases node with alias properties for
323  * a peripheral. For example, for usb you could have:
324  *
325  * aliases {
326  *		usb0 = "/ehci@c5008000";
327  *		usb1 = "/ehci@c5000000";
328  * };
329  *
330  * Pass "usb" as the name to this function and will return a list of two
331  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
332  *
333  * All nodes returned will match the compatible ID, as it is assumed that
334  * all peripherals use the same driver.
335  *
336  * If no alias node is found, then the node list will be returned in the
337  * order found in the fdt. If the aliases mention a node which doesn't
338  * exist, then this will be ignored. If nodes are found with no aliases,
339  * they will be added in any order.
340  *
341  * If there is a gap in the aliases, then this function return a 0 node at
342  * that position. The return value will also count these gaps.
343  *
344  * This function checks node properties and will not return nodes which are
345  * marked disabled (status = "disabled").
346  *
347  * @param blob		FDT blob to use
348  * @param name		Root name of alias to search for
349  * @param id		Compatible ID to look for
350  * @param node_list	Place to put list of found nodes
351  * @param maxcount	Maximum number of nodes to find
352  * @return number of nodes found on success, FTD_ERR_... on error
353  */
354 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
355 			enum fdt_compat_id id, int *node_list, int maxcount);
356 
357 /*
358  * This function is similar to fdtdec_find_aliases_for_id() except that it
359  * adds to the node_list that is passed in. Any 0 elements are considered
360  * available for allocation - others are considered already used and are
361  * skipped.
362  *
363  * You can use this by calling fdtdec_find_aliases_for_id() with an
364  * uninitialised array, then setting the elements that are returned to -1,
365  * say, then calling this function, perhaps with a different compat id.
366  * Any elements you get back that are >0 are new nodes added by the call
367  * to this function.
368  *
369  * Note that if you have some nodes with aliases and some without, you are
370  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
371  * one compat_id may fill in positions for which you have aliases defined
372  * for another compat_id. When you later call *this* function with the second
373  * compat_id, the alias positions may already be used. A debug warning may
374  * be generated in this case, but it is safest to define aliases for all
375  * nodes when you care about the ordering.
376  */
377 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
378 			enum fdt_compat_id id, int *node_list, int maxcount);
379 
380 /**
381  * Get the alias sequence number of a node
382  *
383  * This works out whether a node is pointed to by an alias, and if so, the
384  * sequence number of that alias. Aliases are of the form <base><num> where
385  * <num> is the sequence number. For example spi2 would be sequence number
386  * 2.
387  *
388  * @param blob		Device tree blob (if NULL, then error is returned)
389  * @param base		Base name for alias (before the underscore)
390  * @param node		Node to look up
391  * @param seqp		This is set to the sequence number if one is found,
392  *			but otherwise the value is left alone
393  * @return 0 if a sequence was found, -ve if not
394  */
395 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
396 			 int *seqp);
397 
398 /**
399  * Get the offset of the given chosen node
400  *
401  * This looks up a property in /chosen containing the path to another node,
402  * then finds the offset of that node.
403  *
404  * @param blob		Device tree blob (if NULL, then error is returned)
405  * @param name		Property name, e.g. "stdout-path"
406  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
407  */
408 int fdtdec_get_chosen_node(const void *blob, const char *name);
409 
410 /*
411  * Get the name for a compatible ID
412  *
413  * @param id		Compatible ID to look for
414  * @return compatible string for that id
415  */
416 const char *fdtdec_get_compatible(enum fdt_compat_id id);
417 
418 /* Look up a phandle and follow it to its node. Then return the offset
419  * of that node.
420  *
421  * @param blob		FDT blob
422  * @param node		node to examine
423  * @param prop_name	name of property to find
424  * @return node offset if found, -ve error code on error
425  */
426 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
427 
428 /**
429  * Look up a property in a node and return its contents in an integer
430  * array of given length. The property must have at least enough data for
431  * the array (4*count bytes). It may have more, but this will be ignored.
432  *
433  * @param blob		FDT blob
434  * @param node		node to examine
435  * @param prop_name	name of property to find
436  * @param array		array to fill with data
437  * @param count		number of array elements
438  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
439  *		or -FDT_ERR_BADLAYOUT if not enough data
440  */
441 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
442 		u32 *array, int count);
443 
444 /**
445  * Look up a property in a node and return its contents in an integer
446  * array of given length. The property must exist but may have less data that
447  * expected (4*count bytes). It may have more, but this will be ignored.
448  *
449  * @param blob		FDT blob
450  * @param node		node to examine
451  * @param prop_name	name of property to find
452  * @param array		array to fill with data
453  * @param count		number of array elements
454  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
455  *		property is not found
456  */
457 int fdtdec_get_int_array_count(const void *blob, int node,
458 			       const char *prop_name, u32 *array, int count);
459 
460 /**
461  * Look up a property in a node and return a pointer to its contents as a
462  * unsigned int array of given length. The property must have at least enough
463  * data for the array ('count' cells). It may have more, but this will be
464  * ignored. The data is not copied.
465  *
466  * Note that you must access elements of the array with fdt32_to_cpu(),
467  * since the elements will be big endian even on a little endian machine.
468  *
469  * @param blob		FDT blob
470  * @param node		node to examine
471  * @param prop_name	name of property to find
472  * @param count		number of array elements
473  * @return pointer to array if found, or NULL if the property is not
474  *		found or there is not enough data
475  */
476 const u32 *fdtdec_locate_array(const void *blob, int node,
477 			       const char *prop_name, int count);
478 
479 /**
480  * Look up a boolean property in a node and return it.
481  *
482  * A boolean properly is true if present in the device tree and false if not
483  * present, regardless of its value.
484  *
485  * @param blob	FDT blob
486  * @param node	node to examine
487  * @param prop_name	name of property to find
488  * @return 1 if the properly is present; 0 if it isn't present
489  */
490 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
491 
492 /**
493  * Decode a single GPIOs from an FDT.
494  *
495  * If the property is not found, then the GPIO structure will still be
496  * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
497  * provide optional GPIOs.
498  *
499  * @param blob		FDT blob to use
500  * @param node		Node to look at
501  * @param prop_name	Node property name
502  * @param gpio		gpio elements to fill from FDT
503  * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
504  */
505 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
506 		struct fdt_gpio_state *gpio);
507 
508 /**
509  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
510  * terminating item.
511  *
512  * @param blob         FDT blob to use
513  * @param node         Node to look at
514  * @param prop_name    Node property name
515  * @param gpio         Array of gpio elements to fill from FDT. This will be
516  *                     untouched if either 0 or an error is returned
517  * @param max_count    Maximum number of elements allowed
518  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
519  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
520  */
521 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
522 		struct fdt_gpio_state *gpio, int max_count);
523 
524 /**
525  * Set up a GPIO pin according to the provided gpio information. At present this
526  * just requests the GPIO.
527  *
528  * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
529  * deal with optional GPIOs.
530  *
531  * @param gpio		GPIO info to use for set up
532  * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
533  */
534 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
535 
536 /**
537  * Look in the FDT for a config item with the given name and return its value
538  * as a 32-bit integer. The property must have at least 4 bytes of data. The
539  * value of the first cell is returned.
540  *
541  * @param blob		FDT blob to use
542  * @param prop_name	Node property name
543  * @param default_val	default value to return if the property is not found
544  * @return integer value, if found, or default_val if not
545  */
546 int fdtdec_get_config_int(const void *blob, const char *prop_name,
547 		int default_val);
548 
549 /**
550  * Look in the FDT for a config item with the given name
551  * and return whether it exists.
552  *
553  * @param blob		FDT blob
554  * @param prop_name	property name to look up
555  * @return 1, if it exists, or 0 if not
556  */
557 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
558 
559 /**
560  * Look in the FDT for a config item with the given name and return its value
561  * as a string.
562  *
563  * @param blob          FDT blob
564  * @param prop_name     property name to look up
565  * @returns property string, NULL on error.
566  */
567 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
568 
569 /*
570  * Look up a property in a node and return its contents in a byte
571  * array of given length. The property must have at least enough data for
572  * the array (count bytes). It may have more, but this will be ignored.
573  *
574  * @param blob		FDT blob
575  * @param node		node to examine
576  * @param prop_name	name of property to find
577  * @param array		array to fill with data
578  * @param count		number of array elements
579  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
580  *		or -FDT_ERR_BADLAYOUT if not enough data
581  */
582 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
583 		u8 *array, int count);
584 
585 /**
586  * Look up a property in a node and return a pointer to its contents as a
587  * byte array of given length. The property must have at least enough data
588  * for the array (count bytes). It may have more, but this will be ignored.
589  * The data is not copied.
590  *
591  * @param blob		FDT blob
592  * @param node		node to examine
593  * @param prop_name	name of property to find
594  * @param count		number of array elements
595  * @return pointer to byte array if found, or NULL if the property is not
596  *		found or there is not enough data
597  */
598 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
599 			     const char *prop_name, int count);
600 
601 /**
602  * Look up a property in a node which contains a memory region address and
603  * size. Then return a pointer to this address.
604  *
605  * The property must hold one address with a length. This is only tested on
606  * 32-bit machines.
607  *
608  * @param blob		FDT blob
609  * @param node		node to examine
610  * @param prop_name	name of property to find
611  * @param basep		Returns base address of region
612  * @param size		Returns size of region
613  * @return 0 if ok, -1 on error (property not found)
614  */
615 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
616 			 fdt_addr_t *basep, fdt_size_t *sizep);
617 
618 enum fmap_compress_t {
619 	FMAP_COMPRESS_NONE,
620 	FMAP_COMPRESS_LZO,
621 };
622 
623 enum fmap_hash_t {
624 	FMAP_HASH_NONE,
625 	FMAP_HASH_SHA1,
626 	FMAP_HASH_SHA256,
627 };
628 
629 /* A flash map entry, containing an offset and length */
630 struct fmap_entry {
631 	uint32_t offset;
632 	uint32_t length;
633 	uint32_t used;			/* Number of bytes used in region */
634 	enum fmap_compress_t compress_algo;	/* Compression type */
635 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
636 	const uint8_t *hash;			/* Hash value */
637 	int hash_size;				/* Hash size */
638 };
639 
640 /**
641  * Read a flash entry from the fdt
642  *
643  * @param blob		FDT blob
644  * @param node		Offset of node to read
645  * @param name		Name of node being read
646  * @param entry		Place to put offset and size of this node
647  * @return 0 if ok, -ve on error
648  */
649 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
650 			   struct fmap_entry *entry);
651 
652 /**
653  * Obtain an indexed resource from a device property.
654  *
655  * @param fdt		FDT blob
656  * @param node		node to examine
657  * @param property	name of the property to parse
658  * @param index		index of the resource to retrieve
659  * @param res		returns the resource
660  * @return 0 if ok, negative on error
661  */
662 int fdt_get_resource(const void *fdt, int node, const char *property,
663 		     unsigned int index, struct fdt_resource *res);
664 
665 /**
666  * Obtain a named resource from a device property.
667  *
668  * Look up the index of the name in a list of strings and return the resource
669  * at that index.
670  *
671  * @param fdt		FDT blob
672  * @param node		node to examine
673  * @param property	name of the property to parse
674  * @param prop_names	name of the property containing the list of names
675  * @param name		the name of the entry to look up
676  * @param res		returns the resource
677  */
678 int fdt_get_named_resource(const void *fdt, int node, const char *property,
679 			   const char *prop_names, const char *name,
680 			   struct fdt_resource *res);
681 
682 /**
683  * Look at the reg property of a device node that represents a PCI device
684  * and parse the bus, device and function number from it.
685  *
686  * @param fdt		FDT blob
687  * @param node		node to examine
688  * @param bdf		returns bus, device, function triplet
689  * @return 0 if ok, negative on error
690  */
691 int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf);
692 
693 /**
694  * Decode a named region within a memory bank of a given type.
695  *
696  * This function handles selection of a memory region. The region is
697  * specified as an offset/size within a particular type of memory.
698  *
699  * The properties used are:
700  *
701  *	<mem_type>-memory<suffix> for the name of the memory bank
702  *	<mem_type>-offset<suffix> for the offset in that bank
703  *
704  * The property value must have an offset and a size. The function checks
705  * that the region is entirely within the memory bank.5
706  *
707  * @param blob		FDT blob
708  * @param node		Node containing the properties (-1 for /config)
709  * @param mem_type	Type of memory to use, which is a name, such as
710  *			"u-boot" or "kernel".
711  * @param suffix	String to append to the memory/offset
712  *			property names
713  * @param basep		Returns base of region
714  * @param sizep		Returns size of region
715  * @return 0 if OK, -ive on error
716  */
717 int fdtdec_decode_memory_region(const void *blob, int node,
718 				const char *mem_type, const char *suffix,
719 				fdt_addr_t *basep, fdt_size_t *sizep);
720 #endif
721