xref: /openbmc/u-boot/include/fdtdec.h (revision 0c331ebc)
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_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
90 	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
91 	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */
92 	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
93 	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */
94 	COMPAT_SAMSUNG_EXYNOS_SPI,	/* Exynos SPI */
95 	COMPAT_GOOGLE_CROS_EC,		/* Google CROS_EC Protocol */
96 	COMPAT_GOOGLE_CROS_EC_KEYB,	/* Google CROS_EC Keyboard */
97 	COMPAT_SAMSUNG_EXYNOS_EHCI,	/* Exynos EHCI controller */
98 	COMPAT_SAMSUNG_EXYNOS5_XHCI,	/* Exynos5 XHCI controller */
99 	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */
100 	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
101 	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */
102 	COMPAT_SAMSUNG_EXYNOS_FIMD,	/* Exynos Display controller */
103 	COMPAT_SAMSUNG_EXYNOS_MIPI_DSI,	/* Exynos mipi dsi */
104 	COMPAT_SAMSUNG_EXYNOS5_DP,	/* Exynos Display port controller */
105 	COMPAT_SAMSUNG_EXYNOS_DWMMC,	/* Exynos DWMMC controller */
106 	COMPAT_SAMSUNG_EXYNOS_MMC,	/* Exynos MMC controller */
107 	COMPAT_SAMSUNG_EXYNOS_SERIAL,	/* Exynos UART */
108 	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */
109 	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */
110 	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */
111 	COMPAT_INFINEON_SLB9635_TPM,	/* Infineon SLB9635 TPM */
112 	COMPAT_INFINEON_SLB9645_TPM,	/* Infineon SLB9645 TPM */
113 	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */
114 	COMPAT_SANDBOX_HOST_EMULATION,	/* Sandbox emulation of a function */
115 	COMPAT_SANDBOX_LCD_SDL,		/* Sandbox LCD emulation with SDL */
116 	COMPAT_TI_TPS65090,		/* Texas Instrument TPS65090 */
117 	COMPAT_NXP_PTN3460,		/* NXP PTN3460 DP/LVDS bridge */
118 	COMPAT_SAMSUNG_EXYNOS_SYSMMU,	/* Exynos sysmmu */
119 	COMPAT_PARADE_PS8625,		/* Parade PS8622 EDP->LVDS bridge */
120 	COMPAT_INTEL_LPC,		/* Intel Low Pin Count I/F */
121 	COMPAT_INTEL_MICROCODE,		/* Intel microcode update */
122 	COMPAT_MEMORY_SPD,		/* Memory SPD information */
123 	COMPAT_INTEL_PANTHERPOINT_AHCI,	/* Intel Pantherpoint AHCI */
124 	COMPAT_INTEL_MODEL_206AX,	/* Intel Model 206AX CPU */
125 	COMPAT_INTEL_GMA,		/* Intel Graphics Media Accelerator */
126 
127 	COMPAT_COUNT,
128 };
129 
130 /* GPIOs are numbered from 0 */
131 enum {
132 	FDT_GPIO_NONE = -1U,	/* an invalid GPIO used to end our list */
133 
134 	FDT_GPIO_ACTIVE_LOW = 1 << 0,	/* input is active low (else high) */
135 };
136 
137 /* This is the state of a GPIO pin as defined by the fdt */
138 struct fdt_gpio_state {
139 	const char *name;	/* name of the fdt property defining this */
140 	uint gpio;		/* GPIO number, or FDT_GPIO_NONE if none */
141 	u8 flags;		/* FDT_GPIO_... flags */
142 };
143 
144 /* This tells us whether a fdt_gpio_state record is valid or not */
145 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
146 
147 /**
148  * Read the GPIO taking into account the polarity of the pin.
149  *
150  * @param gpio		pointer to the decoded gpio
151  * @return value of the gpio if successful, < 0 if unsuccessful
152  */
153 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
154 
155 /**
156  * Write the GPIO taking into account the polarity of the pin.
157  *
158  * @param gpio		pointer to the decoded gpio
159  * @return 0 if successful
160  */
161 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
162 
163 /**
164  * Find the next numbered alias for a peripheral. This is used to enumerate
165  * all the peripherals of a certain type.
166  *
167  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
168  * this function will return a pointer to the node the alias points to, and
169  * then update *upto to 1. Next time you call this function, the next node
170  * will be returned.
171  *
172  * All nodes returned will match the compatible ID, as it is assumed that
173  * all peripherals use the same driver.
174  *
175  * @param blob		FDT blob to use
176  * @param name		Root name of alias to search for
177  * @param id		Compatible ID to look for
178  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
179  */
180 int fdtdec_next_alias(const void *blob, const char *name,
181 		enum fdt_compat_id id, int *upto);
182 
183 /**
184  * Find the compatible ID for a given node.
185  *
186  * Generally each node has at least one compatible string attached to it.
187  * This function looks through our list of known compatible strings and
188  * returns the corresponding ID which matches the compatible string.
189  *
190  * @param blob		FDT blob to use
191  * @param node		Node containing compatible string to find
192  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
193  */
194 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
195 
196 /**
197  * Find the next compatible node for a peripheral.
198  *
199  * Do the first call with node = 0. This function will return a pointer to
200  * the next compatible node. Next time you call this function, pass the
201  * value returned, and the next node will be provided.
202  *
203  * @param blob		FDT blob to use
204  * @param node		Start node for search
205  * @param id		Compatible ID to look for (enum fdt_compat_id)
206  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
207  */
208 int fdtdec_next_compatible(const void *blob, int node,
209 		enum fdt_compat_id id);
210 
211 /**
212  * Find the next compatible subnode for a peripheral.
213  *
214  * Do the first call with node set to the parent and depth = 0. This
215  * function will return the offset of the next compatible node. Next time
216  * you call this function, pass the node value returned last time, with
217  * depth unchanged, and the next node will be provided.
218  *
219  * @param blob		FDT blob to use
220  * @param node		Start node for search
221  * @param id		Compatible ID to look for (enum fdt_compat_id)
222  * @param depthp	Current depth (set to 0 before first call)
223  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
224  */
225 int fdtdec_next_compatible_subnode(const void *blob, int node,
226 		enum fdt_compat_id id, int *depthp);
227 
228 /**
229  * Look up an address property in a node and return it as an address.
230  * The property must hold either one address with no trailing data or
231  * one address with a length. This is only tested on 32-bit machines.
232  *
233  * @param blob	FDT blob
234  * @param node	node to examine
235  * @param prop_name	name of property to find
236  * @return address, if found, or FDT_ADDR_T_NONE if not
237  */
238 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
239 		const char *prop_name);
240 
241 /**
242  * Look up an address property in a node and return it as an address.
243  * The property must hold one address with a length. This is only tested
244  * on 32-bit machines.
245  *
246  * @param blob	FDT blob
247  * @param node	node to examine
248  * @param prop_name	name of property to find
249  * @return address, if found, or FDT_ADDR_T_NONE if not
250  */
251 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
252 		const char *prop_name, fdt_size_t *sizep);
253 
254 /**
255  * Look up a 32-bit integer property in a node and return it. The property
256  * must have at least 4 bytes of data. The value of the first cell is
257  * returned.
258  *
259  * @param blob	FDT blob
260  * @param node	node to examine
261  * @param prop_name	name of property to find
262  * @param default_val	default value to return if the property is not found
263  * @return integer value, if found, or default_val if not
264  */
265 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
266 		s32 default_val);
267 
268 /**
269  * Look up a 64-bit integer property in a node and return it. The property
270  * must have at least 8 bytes of data (2 cells). The first two cells are
271  * concatenated to form a 8 bytes value, where the first cell is top half and
272  * the second cell is bottom half.
273  *
274  * @param blob	FDT blob
275  * @param node	node to examine
276  * @param prop_name	name of property to find
277  * @param default_val	default value to return if the property is not found
278  * @return integer value, if found, or default_val if not
279  */
280 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
281 		uint64_t default_val);
282 
283 /**
284  * Checks whether a node is enabled.
285  * This looks for a 'status' property. If this exists, then returns 1 if
286  * the status is 'ok' and 0 otherwise. If there is no status property,
287  * it returns 1 on the assumption that anything mentioned should be enabled
288  * by default.
289  *
290  * @param blob	FDT blob
291  * @param node	node to examine
292  * @return integer value 0 (not enabled) or 1 (enabled)
293  */
294 int fdtdec_get_is_enabled(const void *blob, int node);
295 
296 /**
297  * Make sure we have a valid fdt available to control U-Boot.
298  *
299  * If not, a message is printed to the console if the console is ready.
300  *
301  * @return 0 if all ok, -1 if not
302  */
303 int fdtdec_prepare_fdt(void);
304 
305 /**
306  * Checks that we have a valid fdt available to control U-Boot.
307 
308  * However, if not then for the moment nothing is done, since this function
309  * is called too early to panic().
310  *
311  * @returns 0
312  */
313 int fdtdec_check_fdt(void);
314 
315 /**
316  * Find the nodes for a peripheral and return a list of them in the correct
317  * order. This is used to enumerate all the peripherals of a certain type.
318  *
319  * To use this, optionally set up a /aliases node with alias properties for
320  * a peripheral. For example, for usb you could have:
321  *
322  * aliases {
323  *		usb0 = "/ehci@c5008000";
324  *		usb1 = "/ehci@c5000000";
325  * };
326  *
327  * Pass "usb" as the name to this function and will return a list of two
328  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
329  *
330  * All nodes returned will match the compatible ID, as it is assumed that
331  * all peripherals use the same driver.
332  *
333  * If no alias node is found, then the node list will be returned in the
334  * order found in the fdt. If the aliases mention a node which doesn't
335  * exist, then this will be ignored. If nodes are found with no aliases,
336  * they will be added in any order.
337  *
338  * If there is a gap in the aliases, then this function return a 0 node at
339  * that position. The return value will also count these gaps.
340  *
341  * This function checks node properties and will not return nodes which are
342  * marked disabled (status = "disabled").
343  *
344  * @param blob		FDT blob to use
345  * @param name		Root name of alias to search for
346  * @param id		Compatible ID to look for
347  * @param node_list	Place to put list of found nodes
348  * @param maxcount	Maximum number of nodes to find
349  * @return number of nodes found on success, FTD_ERR_... on error
350  */
351 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
352 			enum fdt_compat_id id, int *node_list, int maxcount);
353 
354 /*
355  * This function is similar to fdtdec_find_aliases_for_id() except that it
356  * adds to the node_list that is passed in. Any 0 elements are considered
357  * available for allocation - others are considered already used and are
358  * skipped.
359  *
360  * You can use this by calling fdtdec_find_aliases_for_id() with an
361  * uninitialised array, then setting the elements that are returned to -1,
362  * say, then calling this function, perhaps with a different compat id.
363  * Any elements you get back that are >0 are new nodes added by the call
364  * to this function.
365  *
366  * Note that if you have some nodes with aliases and some without, you are
367  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
368  * one compat_id may fill in positions for which you have aliases defined
369  * for another compat_id. When you later call *this* function with the second
370  * compat_id, the alias positions may already be used. A debug warning may
371  * be generated in this case, but it is safest to define aliases for all
372  * nodes when you care about the ordering.
373  */
374 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
375 			enum fdt_compat_id id, int *node_list, int maxcount);
376 
377 /**
378  * Get the alias sequence number of a node
379  *
380  * This works out whether a node is pointed to by an alias, and if so, the
381  * sequence number of that alias. Aliases are of the form <base><num> where
382  * <num> is the sequence number. For example spi2 would be sequence number
383  * 2.
384  *
385  * @param blob		Device tree blob (if NULL, then error is returned)
386  * @param base		Base name for alias (before the underscore)
387  * @param node		Node to look up
388  * @param seqp		This is set to the sequence number if one is found,
389  *			but otherwise the value is left alone
390  * @return 0 if a sequence was found, -ve if not
391  */
392 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
393 			 int *seqp);
394 
395 /**
396  * Get the offset of the given chosen node
397  *
398  * This looks up a property in /chosen containing the path to another node,
399  * then finds the offset of that node.
400  *
401  * @param blob		Device tree blob (if NULL, then error is returned)
402  * @param name		Property name, e.g. "stdout-path"
403  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
404  */
405 int fdtdec_get_chosen_node(const void *blob, const char *name);
406 
407 /*
408  * Get the name for a compatible ID
409  *
410  * @param id		Compatible ID to look for
411  * @return compatible string for that id
412  */
413 const char *fdtdec_get_compatible(enum fdt_compat_id id);
414 
415 /* Look up a phandle and follow it to its node. Then return the offset
416  * of that node.
417  *
418  * @param blob		FDT blob
419  * @param node		node to examine
420  * @param prop_name	name of property to find
421  * @return node offset if found, -ve error code on error
422  */
423 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
424 
425 /**
426  * Look up a property in a node and return its contents in an integer
427  * array of given length. The property must have at least enough data for
428  * the array (4*count bytes). It may have more, but this will be ignored.
429  *
430  * @param blob		FDT blob
431  * @param node		node to examine
432  * @param prop_name	name of property to find
433  * @param array		array to fill with data
434  * @param count		number of array elements
435  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
436  *		or -FDT_ERR_BADLAYOUT if not enough data
437  */
438 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
439 		u32 *array, int count);
440 
441 /**
442  * Look up a property in a node and return its contents in an integer
443  * array of given length. The property must exist but may have less data that
444  * expected (4*count bytes). It may have more, but this will be ignored.
445  *
446  * @param blob		FDT blob
447  * @param node		node to examine
448  * @param prop_name	name of property to find
449  * @param array		array to fill with data
450  * @param count		number of array elements
451  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
452  *		property is not found
453  */
454 int fdtdec_get_int_array_count(const void *blob, int node,
455 			       const char *prop_name, u32 *array, int count);
456 
457 /**
458  * Look up a property in a node and return a pointer to its contents as a
459  * unsigned int array of given length. The property must have at least enough
460  * data for the array ('count' cells). It may have more, but this will be
461  * ignored. The data is not copied.
462  *
463  * Note that you must access elements of the array with fdt32_to_cpu(),
464  * since the elements will be big endian even on a little endian machine.
465  *
466  * @param blob		FDT blob
467  * @param node		node to examine
468  * @param prop_name	name of property to find
469  * @param count		number of array elements
470  * @return pointer to array if found, or NULL if the property is not
471  *		found or there is not enough data
472  */
473 const u32 *fdtdec_locate_array(const void *blob, int node,
474 			       const char *prop_name, int count);
475 
476 /**
477  * Look up a boolean property in a node and return it.
478  *
479  * A boolean properly is true if present in the device tree and false if not
480  * present, regardless of its value.
481  *
482  * @param blob	FDT blob
483  * @param node	node to examine
484  * @param prop_name	name of property to find
485  * @return 1 if the properly is present; 0 if it isn't present
486  */
487 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
488 
489 /**
490  * Decode a single GPIOs from an FDT.
491  *
492  * If the property is not found, then the GPIO structure will still be
493  * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
494  * provide optional GPIOs.
495  *
496  * @param blob		FDT blob to use
497  * @param node		Node to look at
498  * @param prop_name	Node property name
499  * @param gpio		gpio elements to fill from FDT
500  * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
501  */
502 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
503 		struct fdt_gpio_state *gpio);
504 
505 /**
506  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
507  * terminating item.
508  *
509  * @param blob         FDT blob to use
510  * @param node         Node to look at
511  * @param prop_name    Node property name
512  * @param gpio         Array of gpio elements to fill from FDT. This will be
513  *                     untouched if either 0 or an error is returned
514  * @param max_count    Maximum number of elements allowed
515  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
516  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
517  */
518 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
519 		struct fdt_gpio_state *gpio, int max_count);
520 
521 /**
522  * Set up a GPIO pin according to the provided gpio information. At present this
523  * just requests the GPIO.
524  *
525  * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
526  * deal with optional GPIOs.
527  *
528  * @param gpio		GPIO info to use for set up
529  * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
530  */
531 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
532 
533 /**
534  * Look in the FDT for a config item with the given name and return its value
535  * as a 32-bit integer. The property must have at least 4 bytes of data. The
536  * value of the first cell is returned.
537  *
538  * @param blob		FDT blob to use
539  * @param prop_name	Node property name
540  * @param default_val	default value to return if the property is not found
541  * @return integer value, if found, or default_val if not
542  */
543 int fdtdec_get_config_int(const void *blob, const char *prop_name,
544 		int default_val);
545 
546 /**
547  * Look in the FDT for a config item with the given name
548  * and return whether it exists.
549  *
550  * @param blob		FDT blob
551  * @param prop_name	property name to look up
552  * @return 1, if it exists, or 0 if not
553  */
554 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
555 
556 /**
557  * Look in the FDT for a config item with the given name and return its value
558  * as a string.
559  *
560  * @param blob          FDT blob
561  * @param prop_name     property name to look up
562  * @returns property string, NULL on error.
563  */
564 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
565 
566 /*
567  * Look up a property in a node and return its contents in a byte
568  * array of given length. The property must have at least enough data for
569  * the array (count bytes). It may have more, but this will be ignored.
570  *
571  * @param blob		FDT blob
572  * @param node		node to examine
573  * @param prop_name	name of property to find
574  * @param array		array to fill with data
575  * @param count		number of array elements
576  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
577  *		or -FDT_ERR_BADLAYOUT if not enough data
578  */
579 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
580 		u8 *array, int count);
581 
582 /**
583  * Look up a property in a node and return a pointer to its contents as a
584  * byte array of given length. The property must have at least enough data
585  * for the array (count bytes). It may have more, but this will be ignored.
586  * The data is not copied.
587  *
588  * @param blob		FDT blob
589  * @param node		node to examine
590  * @param prop_name	name of property to find
591  * @param count		number of array elements
592  * @return pointer to byte array if found, or NULL if the property is not
593  *		found or there is not enough data
594  */
595 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
596 			     const char *prop_name, int count);
597 
598 /**
599  * Look up a property in a node which contains a memory region address and
600  * size. Then return a pointer to this address.
601  *
602  * The property must hold one address with a length. This is only tested on
603  * 32-bit machines.
604  *
605  * @param blob		FDT blob
606  * @param node		node to examine
607  * @param prop_name	name of property to find
608  * @param basep		Returns base address of region
609  * @param size		Returns size of region
610  * @return 0 if ok, -1 on error (property not found)
611  */
612 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
613 			 fdt_addr_t *basep, fdt_size_t *sizep);
614 
615 enum fmap_compress_t {
616 	FMAP_COMPRESS_NONE,
617 	FMAP_COMPRESS_LZO,
618 };
619 
620 enum fmap_hash_t {
621 	FMAP_HASH_NONE,
622 	FMAP_HASH_SHA1,
623 	FMAP_HASH_SHA256,
624 };
625 
626 /* A flash map entry, containing an offset and length */
627 struct fmap_entry {
628 	uint32_t offset;
629 	uint32_t length;
630 	uint32_t used;			/* Number of bytes used in region */
631 	enum fmap_compress_t compress_algo;	/* Compression type */
632 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
633 	const uint8_t *hash;			/* Hash value */
634 	int hash_size;				/* Hash size */
635 };
636 
637 /**
638  * Read a flash entry from the fdt
639  *
640  * @param blob		FDT blob
641  * @param node		Offset of node to read
642  * @param name		Name of node being read
643  * @param entry		Place to put offset and size of this node
644  * @return 0 if ok, -ve on error
645  */
646 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
647 			   struct fmap_entry *entry);
648 
649 /**
650  * Obtain an indexed resource from a device property.
651  *
652  * @param fdt		FDT blob
653  * @param node		node to examine
654  * @param property	name of the property to parse
655  * @param index		index of the resource to retrieve
656  * @param res		returns the resource
657  * @return 0 if ok, negative on error
658  */
659 int fdt_get_resource(const void *fdt, int node, const char *property,
660 		     unsigned int index, struct fdt_resource *res);
661 
662 /**
663  * Obtain a named resource from a device property.
664  *
665  * Look up the index of the name in a list of strings and return the resource
666  * at that index.
667  *
668  * @param fdt		FDT blob
669  * @param node		node to examine
670  * @param property	name of the property to parse
671  * @param prop_names	name of the property containing the list of names
672  * @param name		the name of the entry to look up
673  * @param res		returns the resource
674  */
675 int fdt_get_named_resource(const void *fdt, int node, const char *property,
676 			   const char *prop_names, const char *name,
677 			   struct fdt_resource *res);
678 
679 /**
680  * Look at the reg property of a device node that represents a PCI device
681  * and parse the bus, device and function number from it.
682  *
683  * @param fdt		FDT blob
684  * @param node		node to examine
685  * @param bdf		returns bus, device, function triplet
686  * @return 0 if ok, negative on error
687  */
688 int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf);
689 
690 /**
691  * Decode a named region within a memory bank of a given type.
692  *
693  * This function handles selection of a memory region. The region is
694  * specified as an offset/size within a particular type of memory.
695  *
696  * The properties used are:
697  *
698  *	<mem_type>-memory<suffix> for the name of the memory bank
699  *	<mem_type>-offset<suffix> for the offset in that bank
700  *
701  * The property value must have an offset and a size. The function checks
702  * that the region is entirely within the memory bank.5
703  *
704  * @param blob		FDT blob
705  * @param node		Node containing the properties (-1 for /config)
706  * @param mem_type	Type of memory to use, which is a name, such as
707  *			"u-boot" or "kernel".
708  * @param suffix	String to append to the memory/offset
709  *			property names
710  * @param basep		Returns base of region
711  * @param sizep		Returns size of region
712  * @return 0 if OK, -ive on error
713  */
714 int fdtdec_decode_memory_region(const void *blob, int node,
715 				const char *mem_type, const char *suffix,
716 				fdt_addr_t *basep, fdt_size_t *sizep);
717 #endif
718