xref: /openbmc/u-boot/include/fdtdec.h (revision 93322749)
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_PCIE,	/* Tegra 124 PCIe controller */
90 	COMPAT_NVIDIA_TEGRA30_PCIE,	/* Tegra 30 PCIe controller */
91 	COMPAT_NVIDIA_TEGRA20_PCIE,	/* Tegra 20 PCIe controller */
92 	COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
93 					/* Tegra124 XUSB pad controller */
94 	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
95 	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
96 	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */
97 	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
98 	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */
99 	COMPAT_SAMSUNG_EXYNOS_SPI,	/* Exynos SPI */
100 	COMPAT_GOOGLE_CROS_EC,		/* Google CROS_EC Protocol */
101 	COMPAT_GOOGLE_CROS_EC_KEYB,	/* Google CROS_EC Keyboard */
102 	COMPAT_SAMSUNG_EXYNOS_EHCI,	/* Exynos EHCI controller */
103 	COMPAT_SAMSUNG_EXYNOS5_XHCI,	/* Exynos5 XHCI controller */
104 	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */
105 	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
106 	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */
107 	COMPAT_SAMSUNG_EXYNOS_FIMD,	/* Exynos Display controller */
108 	COMPAT_SAMSUNG_EXYNOS_MIPI_DSI,	/* Exynos mipi dsi */
109 	COMPAT_SAMSUNG_EXYNOS5_DP,	/* Exynos Display port controller */
110 	COMPAT_SAMSUNG_EXYNOS_DWMMC,	/* Exynos DWMMC controller */
111 	COMPAT_SAMSUNG_EXYNOS_MMC,	/* Exynos MMC controller */
112 	COMPAT_SAMSUNG_EXYNOS_SERIAL,	/* Exynos UART */
113 	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */
114 	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */
115 	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */
116 	COMPAT_INFINEON_SLB9635_TPM,	/* Infineon SLB9635 TPM */
117 	COMPAT_INFINEON_SLB9645_TPM,	/* Infineon SLB9645 TPM */
118 	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */
119 	COMPAT_SANDBOX_HOST_EMULATION,	/* Sandbox emulation of a function */
120 	COMPAT_SANDBOX_LCD_SDL,		/* Sandbox LCD emulation with SDL */
121 	COMPAT_TI_TPS65090,		/* Texas Instrument TPS65090 */
122 	COMPAT_NXP_PTN3460,		/* NXP PTN3460 DP/LVDS bridge */
123 	COMPAT_SAMSUNG_EXYNOS_SYSMMU,	/* Exynos sysmmu */
124 	COMPAT_PARADE_PS8625,		/* Parade PS8622 EDP->LVDS bridge */
125 	COMPAT_INTEL_LPC,		/* Intel Low Pin Count I/F */
126 	COMPAT_INTEL_MICROCODE,		/* Intel microcode update */
127 	COMPAT_MEMORY_SPD,		/* Memory SPD information */
128 	COMPAT_INTEL_PANTHERPOINT_AHCI,	/* Intel Pantherpoint AHCI */
129 	COMPAT_INTEL_MODEL_206AX,	/* Intel Model 206AX CPU */
130 	COMPAT_INTEL_GMA,		/* Intel Graphics Media Accelerator */
131 	COMPAT_AMS_AS3722,		/* AMS AS3722 PMIC */
132 
133 	COMPAT_COUNT,
134 };
135 
136 /* GPIOs are numbered from 0 */
137 enum {
138 	FDT_GPIO_NONE = -1U,	/* an invalid GPIO used to end our list */
139 
140 	FDT_GPIO_ACTIVE_LOW = 1 << 0,	/* input is active low (else high) */
141 };
142 
143 /* This is the state of a GPIO pin as defined by the fdt */
144 struct fdt_gpio_state {
145 	const char *name;	/* name of the fdt property defining this */
146 	uint gpio;		/* GPIO number, or FDT_GPIO_NONE if none */
147 	u8 flags;		/* FDT_GPIO_... flags */
148 };
149 
150 /* This tells us whether a fdt_gpio_state record is valid or not */
151 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
152 
153 /**
154  * Read the GPIO taking into account the polarity of the pin.
155  *
156  * @param gpio		pointer to the decoded gpio
157  * @return value of the gpio if successful, < 0 if unsuccessful
158  */
159 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
160 
161 /**
162  * Write the GPIO taking into account the polarity of the pin.
163  *
164  * @param gpio		pointer to the decoded gpio
165  * @return 0 if successful
166  */
167 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
168 
169 /**
170  * Find the next numbered alias for a peripheral. This is used to enumerate
171  * all the peripherals of a certain type.
172  *
173  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
174  * this function will return a pointer to the node the alias points to, and
175  * then update *upto to 1. Next time you call this function, the next node
176  * will be returned.
177  *
178  * All nodes returned will match the compatible ID, as it is assumed that
179  * all peripherals use the same driver.
180  *
181  * @param blob		FDT blob to use
182  * @param name		Root name of alias to search for
183  * @param id		Compatible ID to look for
184  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
185  */
186 int fdtdec_next_alias(const void *blob, const char *name,
187 		enum fdt_compat_id id, int *upto);
188 
189 /**
190  * Find the compatible ID for a given node.
191  *
192  * Generally each node has at least one compatible string attached to it.
193  * This function looks through our list of known compatible strings and
194  * returns the corresponding ID which matches the compatible string.
195  *
196  * @param blob		FDT blob to use
197  * @param node		Node containing compatible string to find
198  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
199  */
200 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
201 
202 /**
203  * Find the next compatible node for a peripheral.
204  *
205  * Do the first call with node = 0. This function will return a pointer to
206  * the next compatible node. Next time you call this function, pass the
207  * value returned, and the next node will be provided.
208  *
209  * @param blob		FDT blob to use
210  * @param node		Start node for search
211  * @param id		Compatible ID to look for (enum fdt_compat_id)
212  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
213  */
214 int fdtdec_next_compatible(const void *blob, int node,
215 		enum fdt_compat_id id);
216 
217 /**
218  * Find the next compatible subnode for a peripheral.
219  *
220  * Do the first call with node set to the parent and depth = 0. This
221  * function will return the offset of the next compatible node. Next time
222  * you call this function, pass the node value returned last time, with
223  * depth unchanged, and the next node will be provided.
224  *
225  * @param blob		FDT blob to use
226  * @param node		Start node for search
227  * @param id		Compatible ID to look for (enum fdt_compat_id)
228  * @param depthp	Current depth (set to 0 before first call)
229  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
230  */
231 int fdtdec_next_compatible_subnode(const void *blob, int node,
232 		enum fdt_compat_id id, int *depthp);
233 
234 /**
235  * Look up an address property in a node and return it as an address.
236  * The property must hold either one address with no trailing data or
237  * one address with a length. This is only tested on 32-bit machines.
238  *
239  * @param blob	FDT blob
240  * @param node	node to examine
241  * @param prop_name	name of property to find
242  * @return address, if found, or FDT_ADDR_T_NONE if not
243  */
244 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
245 		const char *prop_name);
246 
247 /**
248  * Look up an address property in a node and return it as an address.
249  * The property must hold one address with a length. This is only tested
250  * on 32-bit machines.
251  *
252  * @param blob	FDT blob
253  * @param node	node to examine
254  * @param prop_name	name of property to find
255  * @return address, if found, or FDT_ADDR_T_NONE if not
256  */
257 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
258 		const char *prop_name, fdt_size_t *sizep);
259 
260 /**
261  * Look up a 32-bit integer property in a node and return it. The property
262  * must have at least 4 bytes of data. The value of the first cell is
263  * returned.
264  *
265  * @param blob	FDT blob
266  * @param node	node to examine
267  * @param prop_name	name of property to find
268  * @param default_val	default value to return if the property is not found
269  * @return integer value, if found, or default_val if not
270  */
271 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
272 		s32 default_val);
273 
274 /**
275  * Look up a 64-bit integer property in a node and return it. The property
276  * must have at least 8 bytes of data (2 cells). The first two cells are
277  * concatenated to form a 8 bytes value, where the first cell is top half and
278  * the second cell is bottom half.
279  *
280  * @param blob	FDT blob
281  * @param node	node to examine
282  * @param prop_name	name of property to find
283  * @param default_val	default value to return if the property is not found
284  * @return integer value, if found, or default_val if not
285  */
286 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
287 		uint64_t default_val);
288 
289 /**
290  * Checks whether a node is enabled.
291  * This looks for a 'status' property. If this exists, then returns 1 if
292  * the status is 'ok' and 0 otherwise. If there is no status property,
293  * it returns 1 on the assumption that anything mentioned should be enabled
294  * by default.
295  *
296  * @param blob	FDT blob
297  * @param node	node to examine
298  * @return integer value 0 (not enabled) or 1 (enabled)
299  */
300 int fdtdec_get_is_enabled(const void *blob, int node);
301 
302 /**
303  * Make sure we have a valid fdt available to control U-Boot.
304  *
305  * If not, a message is printed to the console if the console is ready.
306  *
307  * @return 0 if all ok, -1 if not
308  */
309 int fdtdec_prepare_fdt(void);
310 
311 /**
312  * Checks that we have a valid fdt available to control U-Boot.
313 
314  * However, if not then for the moment nothing is done, since this function
315  * is called too early to panic().
316  *
317  * @returns 0
318  */
319 int fdtdec_check_fdt(void);
320 
321 /**
322  * Find the nodes for a peripheral and return a list of them in the correct
323  * order. This is used to enumerate all the peripherals of a certain type.
324  *
325  * To use this, optionally set up a /aliases node with alias properties for
326  * a peripheral. For example, for usb you could have:
327  *
328  * aliases {
329  *		usb0 = "/ehci@c5008000";
330  *		usb1 = "/ehci@c5000000";
331  * };
332  *
333  * Pass "usb" as the name to this function and will return a list of two
334  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
335  *
336  * All nodes returned will match the compatible ID, as it is assumed that
337  * all peripherals use the same driver.
338  *
339  * If no alias node is found, then the node list will be returned in the
340  * order found in the fdt. If the aliases mention a node which doesn't
341  * exist, then this will be ignored. If nodes are found with no aliases,
342  * they will be added in any order.
343  *
344  * If there is a gap in the aliases, then this function return a 0 node at
345  * that position. The return value will also count these gaps.
346  *
347  * This function checks node properties and will not return nodes which are
348  * marked disabled (status = "disabled").
349  *
350  * @param blob		FDT blob to use
351  * @param name		Root name of alias to search for
352  * @param id		Compatible ID to look for
353  * @param node_list	Place to put list of found nodes
354  * @param maxcount	Maximum number of nodes to find
355  * @return number of nodes found on success, FTD_ERR_... on error
356  */
357 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
358 			enum fdt_compat_id id, int *node_list, int maxcount);
359 
360 /*
361  * This function is similar to fdtdec_find_aliases_for_id() except that it
362  * adds to the node_list that is passed in. Any 0 elements are considered
363  * available for allocation - others are considered already used and are
364  * skipped.
365  *
366  * You can use this by calling fdtdec_find_aliases_for_id() with an
367  * uninitialised array, then setting the elements that are returned to -1,
368  * say, then calling this function, perhaps with a different compat id.
369  * Any elements you get back that are >0 are new nodes added by the call
370  * to this function.
371  *
372  * Note that if you have some nodes with aliases and some without, you are
373  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
374  * one compat_id may fill in positions for which you have aliases defined
375  * for another compat_id. When you later call *this* function with the second
376  * compat_id, the alias positions may already be used. A debug warning may
377  * be generated in this case, but it is safest to define aliases for all
378  * nodes when you care about the ordering.
379  */
380 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
381 			enum fdt_compat_id id, int *node_list, int maxcount);
382 
383 /**
384  * Get the alias sequence number of a node
385  *
386  * This works out whether a node is pointed to by an alias, and if so, the
387  * sequence number of that alias. Aliases are of the form <base><num> where
388  * <num> is the sequence number. For example spi2 would be sequence number
389  * 2.
390  *
391  * @param blob		Device tree blob (if NULL, then error is returned)
392  * @param base		Base name for alias (before the underscore)
393  * @param node		Node to look up
394  * @param seqp		This is set to the sequence number if one is found,
395  *			but otherwise the value is left alone
396  * @return 0 if a sequence was found, -ve if not
397  */
398 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
399 			 int *seqp);
400 
401 /**
402  * Get the offset of the given chosen node
403  *
404  * This looks up a property in /chosen containing the path to another node,
405  * then finds the offset of that node.
406  *
407  * @param blob		Device tree blob (if NULL, then error is returned)
408  * @param name		Property name, e.g. "stdout-path"
409  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
410  */
411 int fdtdec_get_chosen_node(const void *blob, const char *name);
412 
413 /*
414  * Get the name for a compatible ID
415  *
416  * @param id		Compatible ID to look for
417  * @return compatible string for that id
418  */
419 const char *fdtdec_get_compatible(enum fdt_compat_id id);
420 
421 /* Look up a phandle and follow it to its node. Then return the offset
422  * of that node.
423  *
424  * @param blob		FDT blob
425  * @param node		node to examine
426  * @param prop_name	name of property to find
427  * @return node offset if found, -ve error code on error
428  */
429 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
430 
431 /**
432  * Look up a property in a node and return its contents in an integer
433  * array of given length. The property must have at least enough data for
434  * the array (4*count bytes). It may have more, but this will be ignored.
435  *
436  * @param blob		FDT blob
437  * @param node		node to examine
438  * @param prop_name	name of property to find
439  * @param array		array to fill with data
440  * @param count		number of array elements
441  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
442  *		or -FDT_ERR_BADLAYOUT if not enough data
443  */
444 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
445 		u32 *array, int count);
446 
447 /**
448  * Look up a property in a node and return its contents in an integer
449  * array of given length. The property must exist but may have less data that
450  * expected (4*count bytes). It may have more, but this will be ignored.
451  *
452  * @param blob		FDT blob
453  * @param node		node to examine
454  * @param prop_name	name of property to find
455  * @param array		array to fill with data
456  * @param count		number of array elements
457  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
458  *		property is not found
459  */
460 int fdtdec_get_int_array_count(const void *blob, int node,
461 			       const char *prop_name, u32 *array, int count);
462 
463 /**
464  * Look up a property in a node and return a pointer to its contents as a
465  * unsigned int array of given length. The property must have at least enough
466  * data for the array ('count' cells). It may have more, but this will be
467  * ignored. The data is not copied.
468  *
469  * Note that you must access elements of the array with fdt32_to_cpu(),
470  * since the elements will be big endian even on a little endian machine.
471  *
472  * @param blob		FDT blob
473  * @param node		node to examine
474  * @param prop_name	name of property to find
475  * @param count		number of array elements
476  * @return pointer to array if found, or NULL if the property is not
477  *		found or there is not enough data
478  */
479 const u32 *fdtdec_locate_array(const void *blob, int node,
480 			       const char *prop_name, int count);
481 
482 /**
483  * Look up a boolean property in a node and return it.
484  *
485  * A boolean properly is true if present in the device tree and false if not
486  * present, regardless of its value.
487  *
488  * @param blob	FDT blob
489  * @param node	node to examine
490  * @param prop_name	name of property to find
491  * @return 1 if the properly is present; 0 if it isn't present
492  */
493 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
494 
495 /**
496  * Decode a single GPIOs from an FDT.
497  *
498  * If the property is not found, then the GPIO structure will still be
499  * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
500  * provide optional GPIOs.
501  *
502  * @param blob		FDT blob to use
503  * @param node		Node to look at
504  * @param prop_name	Node property name
505  * @param gpio		gpio elements to fill from FDT
506  * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
507  */
508 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
509 		struct fdt_gpio_state *gpio);
510 
511 /**
512  * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
513  * terminating item.
514  *
515  * @param blob         FDT blob to use
516  * @param node         Node to look at
517  * @param prop_name    Node property name
518  * @param gpio         Array of gpio elements to fill from FDT. This will be
519  *                     untouched if either 0 or an error is returned
520  * @param max_count    Maximum number of elements allowed
521  * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
522  * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
523  */
524 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
525 		struct fdt_gpio_state *gpio, int max_count);
526 
527 /**
528  * Set up a GPIO pin according to the provided gpio information. At present this
529  * just requests the GPIO.
530  *
531  * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
532  * deal with optional GPIOs.
533  *
534  * @param gpio		GPIO info to use for set up
535  * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
536  */
537 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
538 
539 /**
540  * Look in the FDT for a config item with the given name and return its value
541  * as a 32-bit integer. The property must have at least 4 bytes of data. The
542  * value of the first cell is returned.
543  *
544  * @param blob		FDT blob to use
545  * @param prop_name	Node property name
546  * @param default_val	default value to return if the property is not found
547  * @return integer value, if found, or default_val if not
548  */
549 int fdtdec_get_config_int(const void *blob, const char *prop_name,
550 		int default_val);
551 
552 /**
553  * Look in the FDT for a config item with the given name
554  * and return whether it exists.
555  *
556  * @param blob		FDT blob
557  * @param prop_name	property name to look up
558  * @return 1, if it exists, or 0 if not
559  */
560 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
561 
562 /**
563  * Look in the FDT for a config item with the given name and return its value
564  * as a string.
565  *
566  * @param blob          FDT blob
567  * @param prop_name     property name to look up
568  * @returns property string, NULL on error.
569  */
570 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
571 
572 /*
573  * Look up a property in a node and return its contents in a byte
574  * array of given length. The property must have at least enough data for
575  * the array (count bytes). It may have more, but this will be ignored.
576  *
577  * @param blob		FDT blob
578  * @param node		node to examine
579  * @param prop_name	name of property to find
580  * @param array		array to fill with data
581  * @param count		number of array elements
582  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
583  *		or -FDT_ERR_BADLAYOUT if not enough data
584  */
585 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
586 		u8 *array, int count);
587 
588 /**
589  * Look up a property in a node and return a pointer to its contents as a
590  * byte array of given length. The property must have at least enough data
591  * for the array (count bytes). It may have more, but this will be ignored.
592  * The data is not copied.
593  *
594  * @param blob		FDT blob
595  * @param node		node to examine
596  * @param prop_name	name of property to find
597  * @param count		number of array elements
598  * @return pointer to byte array if found, or NULL if the property is not
599  *		found or there is not enough data
600  */
601 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
602 			     const char *prop_name, int count);
603 
604 /**
605  * Look up a property in a node which contains a memory region address and
606  * size. Then return a pointer to this address.
607  *
608  * The property must hold one address with a length. This is only tested on
609  * 32-bit machines.
610  *
611  * @param blob		FDT blob
612  * @param node		node to examine
613  * @param prop_name	name of property to find
614  * @param basep		Returns base address of region
615  * @param size		Returns size of region
616  * @return 0 if ok, -1 on error (property not found)
617  */
618 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
619 			 fdt_addr_t *basep, fdt_size_t *sizep);
620 
621 enum fmap_compress_t {
622 	FMAP_COMPRESS_NONE,
623 	FMAP_COMPRESS_LZO,
624 };
625 
626 enum fmap_hash_t {
627 	FMAP_HASH_NONE,
628 	FMAP_HASH_SHA1,
629 	FMAP_HASH_SHA256,
630 };
631 
632 /* A flash map entry, containing an offset and length */
633 struct fmap_entry {
634 	uint32_t offset;
635 	uint32_t length;
636 	uint32_t used;			/* Number of bytes used in region */
637 	enum fmap_compress_t compress_algo;	/* Compression type */
638 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
639 	const uint8_t *hash;			/* Hash value */
640 	int hash_size;				/* Hash size */
641 };
642 
643 /**
644  * Read a flash entry from the fdt
645  *
646  * @param blob		FDT blob
647  * @param node		Offset of node to read
648  * @param name		Name of node being read
649  * @param entry		Place to put offset and size of this node
650  * @return 0 if ok, -ve on error
651  */
652 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
653 			   struct fmap_entry *entry);
654 
655 /**
656  * Obtain an indexed resource from a device property.
657  *
658  * @param fdt		FDT blob
659  * @param node		node to examine
660  * @param property	name of the property to parse
661  * @param index		index of the resource to retrieve
662  * @param res		returns the resource
663  * @return 0 if ok, negative on error
664  */
665 int fdt_get_resource(const void *fdt, int node, const char *property,
666 		     unsigned int index, struct fdt_resource *res);
667 
668 /**
669  * Obtain a named resource from a device property.
670  *
671  * Look up the index of the name in a list of strings and return the resource
672  * at that index.
673  *
674  * @param fdt		FDT blob
675  * @param node		node to examine
676  * @param property	name of the property to parse
677  * @param prop_names	name of the property containing the list of names
678  * @param name		the name of the entry to look up
679  * @param res		returns the resource
680  */
681 int fdt_get_named_resource(const void *fdt, int node, const char *property,
682 			   const char *prop_names, const char *name,
683 			   struct fdt_resource *res);
684 
685 /**
686  * Look at the reg property of a device node that represents a PCI device
687  * and parse the bus, device and function number from it.
688  *
689  * @param fdt		FDT blob
690  * @param node		node to examine
691  * @param bdf		returns bus, device, function triplet
692  * @return 0 if ok, negative on error
693  */
694 int fdtdec_pci_get_bdf(const void *fdt, int node, int *bdf);
695 
696 /**
697  * Decode a named region within a memory bank of a given type.
698  *
699  * This function handles selection of a memory region. The region is
700  * specified as an offset/size within a particular type of memory.
701  *
702  * The properties used are:
703  *
704  *	<mem_type>-memory<suffix> for the name of the memory bank
705  *	<mem_type>-offset<suffix> for the offset in that bank
706  *
707  * The property value must have an offset and a size. The function checks
708  * that the region is entirely within the memory bank.5
709  *
710  * @param blob		FDT blob
711  * @param node		Node containing the properties (-1 for /config)
712  * @param mem_type	Type of memory to use, which is a name, such as
713  *			"u-boot" or "kernel".
714  * @param suffix	String to append to the memory/offset
715  *			property names
716  * @param basep		Returns base of region
717  * @param sizep		Returns size of region
718  * @return 0 if OK, -ive on error
719  */
720 int fdtdec_decode_memory_region(const void *blob, int node,
721 				const char *mem_type, const char *suffix,
722 				fdt_addr_t *basep, fdt_size_t *sizep);
723 #endif
724