xref: /rk3399_rockchip-uboot/include/fdtdec.h (revision 0bd4e39d2ba477f3c274aa233f5c2e1d25dbaa74)
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 
124 	COMPAT_COUNT,
125 };
126 
127 /* GPIOs are numbered from 0 */
128 enum {
129 	FDT_GPIO_NONE = -1U,	/* an invalid GPIO used to end our list */
130 
131 	FDT_GPIO_ACTIVE_LOW = 1 << 0,	/* input is active low (else high) */
132 };
133 
134 /* This is the state of a GPIO pin as defined by the fdt */
135 struct fdt_gpio_state {
136 	const char *name;	/* name of the fdt property defining this */
137 	uint gpio;		/* GPIO number, or FDT_GPIO_NONE if none */
138 	u8 flags;		/* FDT_GPIO_... flags */
139 };
140 
141 /* This tells us whether a fdt_gpio_state record is valid or not */
142 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
143 
144 /**
145  * Read the GPIO taking into account the polarity of the pin.
146  *
147  * @param gpio		pointer to the decoded gpio
148  * @return value of the gpio if successful, < 0 if unsuccessful
149  */
150 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
151 
152 /**
153  * Write the GPIO taking into account the polarity of the pin.
154  *
155  * @param gpio		pointer to the decoded gpio
156  * @return 0 if successful
157  */
158 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
159 
160 /**
161  * Find the next numbered alias for a peripheral. This is used to enumerate
162  * all the peripherals of a certain type.
163  *
164  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
165  * this function will return a pointer to the node the alias points to, and
166  * then update *upto to 1. Next time you call this function, the next node
167  * will be returned.
168  *
169  * All nodes returned will match the compatible ID, as it is assumed that
170  * all peripherals use the same driver.
171  *
172  * @param blob		FDT blob to use
173  * @param name		Root name of alias to search for
174  * @param id		Compatible ID to look for
175  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
176  */
177 int fdtdec_next_alias(const void *blob, const char *name,
178 		enum fdt_compat_id id, int *upto);
179 
180 /**
181  * Find the compatible ID for a given node.
182  *
183  * Generally each node has at least one compatible string attached to it.
184  * This function looks through our list of known compatible strings and
185  * returns the corresponding ID which matches the compatible string.
186  *
187  * @param blob		FDT blob to use
188  * @param node		Node containing compatible string to find
189  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
190  */
191 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
192 
193 /**
194  * Find the next compatible node for a peripheral.
195  *
196  * Do the first call with node = 0. This function will return a pointer to
197  * the next compatible node. Next time you call this function, pass the
198  * value returned, and the next node will be provided.
199  *
200  * @param blob		FDT blob to use
201  * @param node		Start node for search
202  * @param id		Compatible ID to look for (enum fdt_compat_id)
203  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
204  */
205 int fdtdec_next_compatible(const void *blob, int node,
206 		enum fdt_compat_id id);
207 
208 /**
209  * Find the next compatible subnode for a peripheral.
210  *
211  * Do the first call with node set to the parent and depth = 0. This
212  * function will return the offset of the next compatible node. Next time
213  * you call this function, pass the node value returned last time, with
214  * depth unchanged, and the next node will be provided.
215  *
216  * @param blob		FDT blob to use
217  * @param node		Start node for search
218  * @param id		Compatible ID to look for (enum fdt_compat_id)
219  * @param depthp	Current depth (set to 0 before first call)
220  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
221  */
222 int fdtdec_next_compatible_subnode(const void *blob, int node,
223 		enum fdt_compat_id id, int *depthp);
224 
225 /**
226  * Look up an address property in a node and return it as an address.
227  * The property must hold either one address with no trailing data or
228  * one address with a length. This is only tested on 32-bit machines.
229  *
230  * @param blob	FDT blob
231  * @param node	node to examine
232  * @param prop_name	name of property to find
233  * @return address, if found, or FDT_ADDR_T_NONE if not
234  */
235 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
236 		const char *prop_name);
237 
238 /**
239  * Look up an address property in a node and return it as an address.
240  * The property must hold one address with a length. This is only tested
241  * on 32-bit machines.
242  *
243  * @param blob	FDT blob
244  * @param node	node to examine
245  * @param prop_name	name of property to find
246  * @return address, if found, or FDT_ADDR_T_NONE if not
247  */
248 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
249 		const char *prop_name, fdt_size_t *sizep);
250 
251 /**
252  * Look up a 32-bit integer property in a node and return it. The property
253  * must have at least 4 bytes of data. The value of the first cell is
254  * returned.
255  *
256  * @param blob	FDT blob
257  * @param node	node to examine
258  * @param prop_name	name of property to find
259  * @param default_val	default value to return if the property is not found
260  * @return integer value, if found, or default_val if not
261  */
262 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
263 		s32 default_val);
264 
265 /**
266  * Look up a 64-bit integer property in a node and return it. The property
267  * must have at least 8 bytes of data (2 cells). The first two cells are
268  * concatenated to form a 8 bytes value, where the first cell is top half and
269  * the second cell is bottom half.
270  *
271  * @param blob	FDT blob
272  * @param node	node to examine
273  * @param prop_name	name of property to find
274  * @param default_val	default value to return if the property is not found
275  * @return integer value, if found, or default_val if not
276  */
277 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
278 		uint64_t default_val);
279 
280 /**
281  * Checks whether a node is enabled.
282  * This looks for a 'status' property. If this exists, then returns 1 if
283  * the status is 'ok' and 0 otherwise. If there is no status property,
284  * it returns 1 on the assumption that anything mentioned should be enabled
285  * by default.
286  *
287  * @param blob	FDT blob
288  * @param node	node to examine
289  * @return integer value 0 (not enabled) or 1 (enabled)
290  */
291 int fdtdec_get_is_enabled(const void *blob, int node);
292 
293 /**
294  * Make sure we have a valid fdt available to control U-Boot.
295  *
296  * If not, a message is printed to the console if the console is ready.
297  *
298  * @return 0 if all ok, -1 if not
299  */
300 int fdtdec_prepare_fdt(void);
301 
302 /**
303  * Checks that we have a valid fdt available to control U-Boot.
304 
305  * However, if not then for the moment nothing is done, since this function
306  * is called too early to panic().
307  *
308  * @returns 0
309  */
310 int fdtdec_check_fdt(void);
311 
312 /**
313  * Find the nodes for a peripheral and return a list of them in the correct
314  * order. This is used to enumerate all the peripherals of a certain type.
315  *
316  * To use this, optionally set up a /aliases node with alias properties for
317  * a peripheral. For example, for usb you could have:
318  *
319  * aliases {
320  *		usb0 = "/ehci@c5008000";
321  *		usb1 = "/ehci@c5000000";
322  * };
323  *
324  * Pass "usb" as the name to this function and will return a list of two
325  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
326  *
327  * All nodes returned will match the compatible ID, as it is assumed that
328  * all peripherals use the same driver.
329  *
330  * If no alias node is found, then the node list will be returned in the
331  * order found in the fdt. If the aliases mention a node which doesn't
332  * exist, then this will be ignored. If nodes are found with no aliases,
333  * they will be added in any order.
334  *
335  * If there is a gap in the aliases, then this function return a 0 node at
336  * that position. The return value will also count these gaps.
337  *
338  * This function checks node properties and will not return nodes which are
339  * marked disabled (status = "disabled").
340  *
341  * @param blob		FDT blob to use
342  * @param name		Root name of alias to search for
343  * @param id		Compatible ID to look for
344  * @param node_list	Place to put list of found nodes
345  * @param maxcount	Maximum number of nodes to find
346  * @return number of nodes found on success, FTD_ERR_... on error
347  */
348 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
349 			enum fdt_compat_id id, int *node_list, int maxcount);
350 
351 /*
352  * This function is similar to fdtdec_find_aliases_for_id() except that it
353  * adds to the node_list that is passed in. Any 0 elements are considered
354  * available for allocation - others are considered already used and are
355  * skipped.
356  *
357  * You can use this by calling fdtdec_find_aliases_for_id() with an
358  * uninitialised array, then setting the elements that are returned to -1,
359  * say, then calling this function, perhaps with a different compat id.
360  * Any elements you get back that are >0 are new nodes added by the call
361  * to this function.
362  *
363  * Note that if you have some nodes with aliases and some without, you are
364  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
365  * one compat_id may fill in positions for which you have aliases defined
366  * for another compat_id. When you later call *this* function with the second
367  * compat_id, the alias positions may already be used. A debug warning may
368  * be generated in this case, but it is safest to define aliases for all
369  * nodes when you care about the ordering.
370  */
371 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
372 			enum fdt_compat_id id, int *node_list, int maxcount);
373 
374 /**
375  * Get the alias sequence number of a node
376  *
377  * This works out whether a node is pointed to by an alias, and if so, the
378  * sequence number of that alias. Aliases are of the form <base><num> where
379  * <num> is the sequence number. For example spi2 would be sequence number
380  * 2.
381  *
382  * @param blob		Device tree blob (if NULL, then error is returned)
383  * @param base		Base name for alias (before the underscore)
384  * @param node		Node to look up
385  * @param seqp		This is set to the sequence number if one is found,
386  *			but otherwise the value is left alone
387  * @return 0 if a sequence was found, -ve if not
388  */
389 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
390 			 int *seqp);
391 
392 /**
393  * Get the offset of the given chosen node
394  *
395  * This looks up a property in /chosen containing the path to another node,
396  * then finds the offset of that node.
397  *
398  * @param blob		Device tree blob (if NULL, then error is returned)
399  * @param name		Property name, e.g. "stdout-path"
400  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
401  */
402 int fdtdec_get_chosen_node(const void *blob, const char *name);
403 
404 /*
405  * Get the name for a compatible ID
406  *
407  * @param id		Compatible ID to look for
408  * @return compatible string for that id
409  */
410 const char *fdtdec_get_compatible(enum fdt_compat_id id);
411 
412 /* Look up a phandle and follow it to its node. Then return the offset
413  * of that node.
414  *
415  * @param blob		FDT blob
416  * @param node		node to examine
417  * @param prop_name	name of property to find
418  * @return node offset if found, -ve error code on error
419  */
420 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
421 
422 /**
423  * Look up a property in a node and return its contents in an integer
424  * array of given length. The property must have at least enough data for
425  * the array (4*count bytes). It may have more, but this will be ignored.
426  *
427  * @param blob		FDT blob
428  * @param node		node to examine
429  * @param prop_name	name of property to find
430  * @param array		array to fill with data
431  * @param count		number of array elements
432  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
433  *		or -FDT_ERR_BADLAYOUT if not enough data
434  */
435 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
436 		u32 *array, int count);
437 
438 /**
439  * Look up a property in a node and return its contents in an integer
440  * array of given length. The property must exist but may have less data that
441  * expected (4*count bytes). It may have more, but this will be ignored.
442  *
443  * @param blob		FDT blob
444  * @param node		node to examine
445  * @param prop_name	name of property to find
446  * @param array		array to fill with data
447  * @param count		number of array elements
448  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
449  *		property is not found
450  */
451 int fdtdec_get_int_array_count(const void *blob, int node,
452 			       const char *prop_name, u32 *array, int count);
453 
454 /**
455  * Look up a property in a node and return a pointer to its contents as a
456  * unsigned int array of given length. The property must have at least enough
457  * data for the array ('count' cells). It may have more, but this will be
458  * ignored. The data is not copied.
459  *
460  * Note that you must access elements of the array with fdt32_to_cpu(),
461  * since the elements will be big endian even on a little endian machine.
462  *
463  * @param blob		FDT blob
464  * @param node		node to examine
465  * @param prop_name	name of property to find
466  * @param count		number of array elements
467  * @return pointer to array if found, or NULL if the property is not
468  *		found or there is not enough data
469  */
470 const u32 *fdtdec_locate_array(const void *blob, int node,
471 			       const char *prop_name, int count);
472 
473 /**
474  * Look up a boolean property in a node and return it.
475  *
476  * A boolean properly is true if present in the device tree and false if not
477  * present, regardless of its value.
478  *
479  * @param blob	FDT blob
480  * @param node	node to examine
481  * @param prop_name	name of property to find
482  * @return 1 if the properly is present; 0 if it isn't present
483  */
484 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
485 
486 /**
487  * Decode a single GPIOs from an FDT.
488  *
489  * If the property is not found, then the GPIO structure will still be
490  * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
491  * provide optional GPIOs.
492  *
493  * @param blob		FDT blob to use
494  * @param node		Node to look at
495  * @param prop_name	Node property name
496  * @param gpio		gpio elements to fill from FDT
497  * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
498  */
499 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
500 		struct fdt_gpio_state *gpio);
501 
502 /**
503  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
504  * terminating item.
505  *
506  * @param blob         FDT blob to use
507  * @param node         Node to look at
508  * @param prop_name    Node property name
509  * @param gpio         Array of gpio elements to fill from FDT. This will be
510  *                     untouched if either 0 or an error is returned
511  * @param max_count    Maximum number of elements allowed
512  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
513  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
514  */
515 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
516 		struct fdt_gpio_state *gpio, int max_count);
517 
518 /**
519  * Set up a GPIO pin according to the provided gpio information. At present this
520  * just requests the GPIO.
521  *
522  * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
523  * deal with optional GPIOs.
524  *
525  * @param gpio		GPIO info to use for set up
526  * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
527  */
528 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
529 
530 /**
531  * Look in the FDT for a config item with the given name and return its value
532  * as a 32-bit integer. The property must have at least 4 bytes of data. The
533  * value of the first cell is returned.
534  *
535  * @param blob		FDT blob to use
536  * @param prop_name	Node property name
537  * @param default_val	default value to return if the property is not found
538  * @return integer value, if found, or default_val if not
539  */
540 int fdtdec_get_config_int(const void *blob, const char *prop_name,
541 		int default_val);
542 
543 /**
544  * Look in the FDT for a config item with the given name
545  * and return whether it exists.
546  *
547  * @param blob		FDT blob
548  * @param prop_name	property name to look up
549  * @return 1, if it exists, or 0 if not
550  */
551 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
552 
553 /**
554  * Look in the FDT for a config item with the given name and return its value
555  * as a string.
556  *
557  * @param blob          FDT blob
558  * @param prop_name     property name to look up
559  * @returns property string, NULL on error.
560  */
561 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
562 
563 /*
564  * Look up a property in a node and return its contents in a byte
565  * array of given length. The property must have at least enough data for
566  * the array (count bytes). It may have more, but this will be ignored.
567  *
568  * @param blob		FDT blob
569  * @param node		node to examine
570  * @param prop_name	name of property to find
571  * @param array		array to fill with data
572  * @param count		number of array elements
573  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
574  *		or -FDT_ERR_BADLAYOUT if not enough data
575  */
576 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
577 		u8 *array, int count);
578 
579 /**
580  * Look up a property in a node and return a pointer to its contents as a
581  * byte array of given length. The property must have at least enough data
582  * for the array (count bytes). It may have more, but this will be ignored.
583  * The data is not copied.
584  *
585  * @param blob		FDT blob
586  * @param node		node to examine
587  * @param prop_name	name of property to find
588  * @param count		number of array elements
589  * @return pointer to byte array if found, or NULL if the property is not
590  *		found or there is not enough data
591  */
592 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
593 			     const char *prop_name, int count);
594 
595 /**
596  * Look up a property in a node which contains a memory region address and
597  * size. Then return a pointer to this address.
598  *
599  * The property must hold one address with a length. This is only tested on
600  * 32-bit machines.
601  *
602  * @param blob		FDT blob
603  * @param node		node to examine
604  * @param prop_name	name of property to find
605  * @param basep		Returns base address of region
606  * @param size		Returns size of region
607  * @return 0 if ok, -1 on error (property not found)
608  */
609 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
610 			 fdt_addr_t *basep, fdt_size_t *sizep);
611 
612 enum fmap_compress_t {
613 	FMAP_COMPRESS_NONE,
614 	FMAP_COMPRESS_LZO,
615 };
616 
617 enum fmap_hash_t {
618 	FMAP_HASH_NONE,
619 	FMAP_HASH_SHA1,
620 	FMAP_HASH_SHA256,
621 };
622 
623 /* A flash map entry, containing an offset and length */
624 struct fmap_entry {
625 	uint32_t offset;
626 	uint32_t length;
627 	uint32_t used;			/* Number of bytes used in region */
628 	enum fmap_compress_t compress_algo;	/* Compression type */
629 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
630 	const uint8_t *hash;			/* Hash value */
631 	int hash_size;				/* Hash size */
632 };
633 
634 /**
635  * Read a flash entry from the fdt
636  *
637  * @param blob		FDT blob
638  * @param node		Offset of node to read
639  * @param name		Name of node being read
640  * @param entry		Place to put offset and size of this node
641  * @return 0 if ok, -ve on error
642  */
643 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
644 			   struct fmap_entry *entry);
645 
646 /**
647  * Obtain an indexed resource from a device property.
648  *
649  * @param fdt		FDT blob
650  * @param node		node to examine
651  * @param property	name of the property to parse
652  * @param index		index of the resource to retrieve
653  * @param res		returns the resource
654  * @return 0 if ok, negative on error
655  */
656 int fdt_get_resource(const void *fdt, int node, const char *property,
657 		     unsigned int index, struct fdt_resource *res);
658 
659 /**
660  * Obtain a named resource from a device property.
661  *
662  * Look up the index of the name in a list of strings and return the resource
663  * at that index.
664  *
665  * @param fdt		FDT blob
666  * @param node		node to examine
667  * @param property	name of the property to parse
668  * @param prop_names	name of the property containing the list of names
669  * @param name		the name of the entry to look up
670  * @param res		returns the resource
671  */
672 int fdt_get_named_resource(const void *fdt, int node, const char *property,
673 			   const char *prop_names, const char *name,
674 			   struct fdt_resource *res);
675 
676 /**
677  * Look at the reg property of a device node that represents a PCI device
678  * and parse the bus, device and function number from it.
679  *
680  * @param fdt		FDT blob
681  * @param node		node to examine
682  * @param bdf		returns bus, device, function triplet
683  * @return 0 if ok, negative on error
684  */
685 int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf);
686 
687 /**
688  * Decode a named region within a memory bank of a given type.
689  *
690  * This function handles selection of a memory region. The region is
691  * specified as an offset/size within a particular type of memory.
692  *
693  * The properties used are:
694  *
695  *	<mem_type>-memory<suffix> for the name of the memory bank
696  *	<mem_type>-offset<suffix> for the offset in that bank
697  *
698  * The property value must have an offset and a size. The function checks
699  * that the region is entirely within the memory bank.5
700  *
701  * @param blob		FDT blob
702  * @param node		Node containing the properties (-1 for /config)
703  * @param mem_type	Type of memory to use, which is a name, such as
704  *			"u-boot" or "kernel".
705  * @param suffix	String to append to the memory/offset
706  *			property names
707  * @param basep		Returns base of region
708  * @param sizep		Returns size of region
709  * @return 0 if OK, -ive on error
710  */
711 int fdtdec_decode_memory_region(const void *blob, int node,
712 				const char *mem_type, const char *suffix,
713 				fdt_addr_t *basep, fdt_size_t *sizep);
714 #endif
715