xref: /rk3399_rockchip-uboot/include/fdtdec.h (revision 48510c089b18482de36210ec3f70d8908e8daf90)
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 	COMPAT_AMS_AS3722,		/* AMS AS3722 PMIC */
127 
128 	COMPAT_COUNT,
129 };
130 
131 /* GPIOs are numbered from 0 */
132 enum {
133 	FDT_GPIO_NONE = -1U,	/* an invalid GPIO used to end our list */
134 
135 	FDT_GPIO_ACTIVE_LOW = 1 << 0,	/* input is active low (else high) */
136 };
137 
138 /* This is the state of a GPIO pin as defined by the fdt */
139 struct fdt_gpio_state {
140 	const char *name;	/* name of the fdt property defining this */
141 	uint gpio;		/* GPIO number, or FDT_GPIO_NONE if none */
142 	u8 flags;		/* FDT_GPIO_... flags */
143 };
144 
145 /* This tells us whether a fdt_gpio_state record is valid or not */
146 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
147 
148 /**
149  * Read the GPIO taking into account the polarity of the pin.
150  *
151  * @param gpio		pointer to the decoded gpio
152  * @return value of the gpio if successful, < 0 if unsuccessful
153  */
154 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
155 
156 /**
157  * Write the GPIO taking into account the polarity of the pin.
158  *
159  * @param gpio		pointer to the decoded gpio
160  * @return 0 if successful
161  */
162 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
163 
164 /**
165  * Find the next numbered alias for a peripheral. This is used to enumerate
166  * all the peripherals of a certain type.
167  *
168  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
169  * this function will return a pointer to the node the alias points to, and
170  * then update *upto to 1. Next time you call this function, the next node
171  * will be returned.
172  *
173  * All nodes returned will match the compatible ID, as it is assumed that
174  * all peripherals use the same driver.
175  *
176  * @param blob		FDT blob to use
177  * @param name		Root name of alias to search for
178  * @param id		Compatible ID to look for
179  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
180  */
181 int fdtdec_next_alias(const void *blob, const char *name,
182 		enum fdt_compat_id id, int *upto);
183 
184 /**
185  * Find the compatible ID for a given node.
186  *
187  * Generally each node has at least one compatible string attached to it.
188  * This function looks through our list of known compatible strings and
189  * returns the corresponding ID which matches the compatible string.
190  *
191  * @param blob		FDT blob to use
192  * @param node		Node containing compatible string to find
193  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
194  */
195 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
196 
197 /**
198  * Find the next compatible node for a peripheral.
199  *
200  * Do the first call with node = 0. This function will return a pointer to
201  * the next compatible node. Next time you call this function, pass the
202  * value returned, and the next node will be provided.
203  *
204  * @param blob		FDT blob to use
205  * @param node		Start node for search
206  * @param id		Compatible ID to look for (enum fdt_compat_id)
207  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
208  */
209 int fdtdec_next_compatible(const void *blob, int node,
210 		enum fdt_compat_id id);
211 
212 /**
213  * Find the next compatible subnode for a peripheral.
214  *
215  * Do the first call with node set to the parent and depth = 0. This
216  * function will return the offset of the next compatible node. Next time
217  * you call this function, pass the node value returned last time, with
218  * depth unchanged, and the next node will be provided.
219  *
220  * @param blob		FDT blob to use
221  * @param node		Start node for search
222  * @param id		Compatible ID to look for (enum fdt_compat_id)
223  * @param depthp	Current depth (set to 0 before first call)
224  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
225  */
226 int fdtdec_next_compatible_subnode(const void *blob, int node,
227 		enum fdt_compat_id id, int *depthp);
228 
229 /**
230  * Look up an address property in a node and return it as an address.
231  * The property must hold either one address with no trailing data or
232  * one address with a length. This is only tested on 32-bit machines.
233  *
234  * @param blob	FDT blob
235  * @param node	node to examine
236  * @param prop_name	name of property to find
237  * @return address, if found, or FDT_ADDR_T_NONE if not
238  */
239 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
240 		const char *prop_name);
241 
242 /**
243  * Look up an address property in a node and return it as an address.
244  * The property must hold one address with a length. This is only tested
245  * on 32-bit machines.
246  *
247  * @param blob	FDT blob
248  * @param node	node to examine
249  * @param prop_name	name of property to find
250  * @return address, if found, or FDT_ADDR_T_NONE if not
251  */
252 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
253 		const char *prop_name, fdt_size_t *sizep);
254 
255 /**
256  * Look up a 32-bit integer property in a node and return it. The property
257  * must have at least 4 bytes of data. The value of the first cell is
258  * returned.
259  *
260  * @param blob	FDT blob
261  * @param node	node to examine
262  * @param prop_name	name of property to find
263  * @param default_val	default value to return if the property is not found
264  * @return integer value, if found, or default_val if not
265  */
266 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
267 		s32 default_val);
268 
269 /**
270  * Look up a 64-bit integer property in a node and return it. The property
271  * must have at least 8 bytes of data (2 cells). The first two cells are
272  * concatenated to form a 8 bytes value, where the first cell is top half and
273  * the second cell is bottom half.
274  *
275  * @param blob	FDT blob
276  * @param node	node to examine
277  * @param prop_name	name of property to find
278  * @param default_val	default value to return if the property is not found
279  * @return integer value, if found, or default_val if not
280  */
281 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
282 		uint64_t default_val);
283 
284 /**
285  * Checks whether a node is enabled.
286  * This looks for a 'status' property. If this exists, then returns 1 if
287  * the status is 'ok' and 0 otherwise. If there is no status property,
288  * it returns 1 on the assumption that anything mentioned should be enabled
289  * by default.
290  *
291  * @param blob	FDT blob
292  * @param node	node to examine
293  * @return integer value 0 (not enabled) or 1 (enabled)
294  */
295 int fdtdec_get_is_enabled(const void *blob, int node);
296 
297 /**
298  * Make sure we have a valid fdt available to control U-Boot.
299  *
300  * If not, a message is printed to the console if the console is ready.
301  *
302  * @return 0 if all ok, -1 if not
303  */
304 int fdtdec_prepare_fdt(void);
305 
306 /**
307  * Checks that we have a valid fdt available to control U-Boot.
308 
309  * However, if not then for the moment nothing is done, since this function
310  * is called too early to panic().
311  *
312  * @returns 0
313  */
314 int fdtdec_check_fdt(void);
315 
316 /**
317  * Find the nodes for a peripheral and return a list of them in the correct
318  * order. This is used to enumerate all the peripherals of a certain type.
319  *
320  * To use this, optionally set up a /aliases node with alias properties for
321  * a peripheral. For example, for usb you could have:
322  *
323  * aliases {
324  *		usb0 = "/ehci@c5008000";
325  *		usb1 = "/ehci@c5000000";
326  * };
327  *
328  * Pass "usb" as the name to this function and will return a list of two
329  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
330  *
331  * All nodes returned will match the compatible ID, as it is assumed that
332  * all peripherals use the same driver.
333  *
334  * If no alias node is found, then the node list will be returned in the
335  * order found in the fdt. If the aliases mention a node which doesn't
336  * exist, then this will be ignored. If nodes are found with no aliases,
337  * they will be added in any order.
338  *
339  * If there is a gap in the aliases, then this function return a 0 node at
340  * that position. The return value will also count these gaps.
341  *
342  * This function checks node properties and will not return nodes which are
343  * marked disabled (status = "disabled").
344  *
345  * @param blob		FDT blob to use
346  * @param name		Root name of alias to search for
347  * @param id		Compatible ID to look for
348  * @param node_list	Place to put list of found nodes
349  * @param maxcount	Maximum number of nodes to find
350  * @return number of nodes found on success, FTD_ERR_... on error
351  */
352 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
353 			enum fdt_compat_id id, int *node_list, int maxcount);
354 
355 /*
356  * This function is similar to fdtdec_find_aliases_for_id() except that it
357  * adds to the node_list that is passed in. Any 0 elements are considered
358  * available for allocation - others are considered already used and are
359  * skipped.
360  *
361  * You can use this by calling fdtdec_find_aliases_for_id() with an
362  * uninitialised array, then setting the elements that are returned to -1,
363  * say, then calling this function, perhaps with a different compat id.
364  * Any elements you get back that are >0 are new nodes added by the call
365  * to this function.
366  *
367  * Note that if you have some nodes with aliases and some without, you are
368  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
369  * one compat_id may fill in positions for which you have aliases defined
370  * for another compat_id. When you later call *this* function with the second
371  * compat_id, the alias positions may already be used. A debug warning may
372  * be generated in this case, but it is safest to define aliases for all
373  * nodes when you care about the ordering.
374  */
375 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
376 			enum fdt_compat_id id, int *node_list, int maxcount);
377 
378 /**
379  * Get the alias sequence number of a node
380  *
381  * This works out whether a node is pointed to by an alias, and if so, the
382  * sequence number of that alias. Aliases are of the form <base><num> where
383  * <num> is the sequence number. For example spi2 would be sequence number
384  * 2.
385  *
386  * @param blob		Device tree blob (if NULL, then error is returned)
387  * @param base		Base name for alias (before the underscore)
388  * @param node		Node to look up
389  * @param seqp		This is set to the sequence number if one is found,
390  *			but otherwise the value is left alone
391  * @return 0 if a sequence was found, -ve if not
392  */
393 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
394 			 int *seqp);
395 
396 /**
397  * Get the offset of the given chosen node
398  *
399  * This looks up a property in /chosen containing the path to another node,
400  * then finds the offset of that node.
401  *
402  * @param blob		Device tree blob (if NULL, then error is returned)
403  * @param name		Property name, e.g. "stdout-path"
404  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
405  */
406 int fdtdec_get_chosen_node(const void *blob, const char *name);
407 
408 /*
409  * Get the name for a compatible ID
410  *
411  * @param id		Compatible ID to look for
412  * @return compatible string for that id
413  */
414 const char *fdtdec_get_compatible(enum fdt_compat_id id);
415 
416 /* Look up a phandle and follow it to its node. Then return the offset
417  * of that node.
418  *
419  * @param blob		FDT blob
420  * @param node		node to examine
421  * @param prop_name	name of property to find
422  * @return node offset if found, -ve error code on error
423  */
424 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
425 
426 /**
427  * Look up a property in a node and return its contents in an integer
428  * array of given length. The property must have at least enough data for
429  * the array (4*count bytes). It may have more, but this will be ignored.
430  *
431  * @param blob		FDT blob
432  * @param node		node to examine
433  * @param prop_name	name of property to find
434  * @param array		array to fill with data
435  * @param count		number of array elements
436  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
437  *		or -FDT_ERR_BADLAYOUT if not enough data
438  */
439 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
440 		u32 *array, int count);
441 
442 /**
443  * Look up a property in a node and return its contents in an integer
444  * array of given length. The property must exist but may have less data that
445  * expected (4*count bytes). It may have more, but this will be ignored.
446  *
447  * @param blob		FDT blob
448  * @param node		node to examine
449  * @param prop_name	name of property to find
450  * @param array		array to fill with data
451  * @param count		number of array elements
452  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
453  *		property is not found
454  */
455 int fdtdec_get_int_array_count(const void *blob, int node,
456 			       const char *prop_name, u32 *array, int count);
457 
458 /**
459  * Look up a property in a node and return a pointer to its contents as a
460  * unsigned int array of given length. The property must have at least enough
461  * data for the array ('count' cells). It may have more, but this will be
462  * ignored. The data is not copied.
463  *
464  * Note that you must access elements of the array with fdt32_to_cpu(),
465  * since the elements will be big endian even on a little endian machine.
466  *
467  * @param blob		FDT blob
468  * @param node		node to examine
469  * @param prop_name	name of property to find
470  * @param count		number of array elements
471  * @return pointer to array if found, or NULL if the property is not
472  *		found or there is not enough data
473  */
474 const u32 *fdtdec_locate_array(const void *blob, int node,
475 			       const char *prop_name, int count);
476 
477 /**
478  * Look up a boolean property in a node and return it.
479  *
480  * A boolean properly is true if present in the device tree and false if not
481  * present, regardless of its value.
482  *
483  * @param blob	FDT blob
484  * @param node	node to examine
485  * @param prop_name	name of property to find
486  * @return 1 if the properly is present; 0 if it isn't present
487  */
488 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
489 
490 /**
491  * Decode a single GPIOs from an FDT.
492  *
493  * If the property is not found, then the GPIO structure will still be
494  * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
495  * provide optional GPIOs.
496  *
497  * @param blob		FDT blob to use
498  * @param node		Node to look at
499  * @param prop_name	Node property name
500  * @param gpio		gpio elements to fill from FDT
501  * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
502  */
503 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
504 		struct fdt_gpio_state *gpio);
505 
506 /**
507  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
508  * terminating item.
509  *
510  * @param blob         FDT blob to use
511  * @param node         Node to look at
512  * @param prop_name    Node property name
513  * @param gpio         Array of gpio elements to fill from FDT. This will be
514  *                     untouched if either 0 or an error is returned
515  * @param max_count    Maximum number of elements allowed
516  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
517  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
518  */
519 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
520 		struct fdt_gpio_state *gpio, int max_count);
521 
522 /**
523  * Set up a GPIO pin according to the provided gpio information. At present this
524  * just requests the GPIO.
525  *
526  * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
527  * deal with optional GPIOs.
528  *
529  * @param gpio		GPIO info to use for set up
530  * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
531  */
532 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
533 
534 /**
535  * Look in the FDT for a config item with the given name and return its value
536  * as a 32-bit integer. The property must have at least 4 bytes of data. The
537  * value of the first cell is returned.
538  *
539  * @param blob		FDT blob to use
540  * @param prop_name	Node property name
541  * @param default_val	default value to return if the property is not found
542  * @return integer value, if found, or default_val if not
543  */
544 int fdtdec_get_config_int(const void *blob, const char *prop_name,
545 		int default_val);
546 
547 /**
548  * Look in the FDT for a config item with the given name
549  * and return whether it exists.
550  *
551  * @param blob		FDT blob
552  * @param prop_name	property name to look up
553  * @return 1, if it exists, or 0 if not
554  */
555 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
556 
557 /**
558  * Look in the FDT for a config item with the given name and return its value
559  * as a string.
560  *
561  * @param blob          FDT blob
562  * @param prop_name     property name to look up
563  * @returns property string, NULL on error.
564  */
565 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
566 
567 /*
568  * Look up a property in a node and return its contents in a byte
569  * array of given length. The property must have at least enough data for
570  * the array (count bytes). It may have more, but this will be ignored.
571  *
572  * @param blob		FDT blob
573  * @param node		node to examine
574  * @param prop_name	name of property to find
575  * @param array		array to fill with data
576  * @param count		number of array elements
577  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
578  *		or -FDT_ERR_BADLAYOUT if not enough data
579  */
580 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
581 		u8 *array, int count);
582 
583 /**
584  * Look up a property in a node and return a pointer to its contents as a
585  * byte array of given length. The property must have at least enough data
586  * for the array (count bytes). It may have more, but this will be ignored.
587  * The data is not copied.
588  *
589  * @param blob		FDT blob
590  * @param node		node to examine
591  * @param prop_name	name of property to find
592  * @param count		number of array elements
593  * @return pointer to byte array if found, or NULL if the property is not
594  *		found or there is not enough data
595  */
596 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
597 			     const char *prop_name, int count);
598 
599 /**
600  * Look up a property in a node which contains a memory region address and
601  * size. Then return a pointer to this address.
602  *
603  * The property must hold one address with a length. This is only tested on
604  * 32-bit machines.
605  *
606  * @param blob		FDT blob
607  * @param node		node to examine
608  * @param prop_name	name of property to find
609  * @param basep		Returns base address of region
610  * @param size		Returns size of region
611  * @return 0 if ok, -1 on error (property not found)
612  */
613 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
614 			 fdt_addr_t *basep, fdt_size_t *sizep);
615 
616 enum fmap_compress_t {
617 	FMAP_COMPRESS_NONE,
618 	FMAP_COMPRESS_LZO,
619 };
620 
621 enum fmap_hash_t {
622 	FMAP_HASH_NONE,
623 	FMAP_HASH_SHA1,
624 	FMAP_HASH_SHA256,
625 };
626 
627 /* A flash map entry, containing an offset and length */
628 struct fmap_entry {
629 	uint32_t offset;
630 	uint32_t length;
631 	uint32_t used;			/* Number of bytes used in region */
632 	enum fmap_compress_t compress_algo;	/* Compression type */
633 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
634 	const uint8_t *hash;			/* Hash value */
635 	int hash_size;				/* Hash size */
636 };
637 
638 /**
639  * Read a flash entry from the fdt
640  *
641  * @param blob		FDT blob
642  * @param node		Offset of node to read
643  * @param name		Name of node being read
644  * @param entry		Place to put offset and size of this node
645  * @return 0 if ok, -ve on error
646  */
647 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
648 			   struct fmap_entry *entry);
649 
650 /**
651  * Obtain an indexed resource from a device property.
652  *
653  * @param fdt		FDT blob
654  * @param node		node to examine
655  * @param property	name of the property to parse
656  * @param index		index of the resource to retrieve
657  * @param res		returns the resource
658  * @return 0 if ok, negative on error
659  */
660 int fdt_get_resource(const void *fdt, int node, const char *property,
661 		     unsigned int index, struct fdt_resource *res);
662 
663 /**
664  * Obtain a named resource from a device property.
665  *
666  * Look up the index of the name in a list of strings and return the resource
667  * at that index.
668  *
669  * @param fdt		FDT blob
670  * @param node		node to examine
671  * @param property	name of the property to parse
672  * @param prop_names	name of the property containing the list of names
673  * @param name		the name of the entry to look up
674  * @param res		returns the resource
675  */
676 int fdt_get_named_resource(const void *fdt, int node, const char *property,
677 			   const char *prop_names, const char *name,
678 			   struct fdt_resource *res);
679 
680 /**
681  * Look at the reg property of a device node that represents a PCI device
682  * and parse the bus, device and function number from it.
683  *
684  * @param fdt		FDT blob
685  * @param node		node to examine
686  * @param bdf		returns bus, device, function triplet
687  * @return 0 if ok, negative on error
688  */
689 int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf);
690 
691 /**
692  * Decode a named region within a memory bank of a given type.
693  *
694  * This function handles selection of a memory region. The region is
695  * specified as an offset/size within a particular type of memory.
696  *
697  * The properties used are:
698  *
699  *	<mem_type>-memory<suffix> for the name of the memory bank
700  *	<mem_type>-offset<suffix> for the offset in that bank
701  *
702  * The property value must have an offset and a size. The function checks
703  * that the region is entirely within the memory bank.5
704  *
705  * @param blob		FDT blob
706  * @param node		Node containing the properties (-1 for /config)
707  * @param mem_type	Type of memory to use, which is a name, such as
708  *			"u-boot" or "kernel".
709  * @param suffix	String to append to the memory/offset
710  *			property names
711  * @param basep		Returns base of region
712  * @param sizep		Returns size of region
713  * @return 0 if OK, -ive on error
714  */
715 int fdtdec_decode_memory_region(const void *blob, int node,
716 				const char *mem_type, const char *suffix,
717 				fdt_addr_t *basep, fdt_size_t *sizep);
718 #endif
719