xref: /openbmc/u-boot/include/fdtdec.h (revision 4d93617d)
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 #include <pci.h>
19 
20 /*
21  * A typedef for a physical address. Note that fdt data is always big
22  * endian even on a litle endian machine.
23  */
24 #ifdef CONFIG_PHYS_64BIT
25 typedef u64 fdt_addr_t;
26 typedef u64 fdt_size_t;
27 #define FDT_ADDR_T_NONE (-1ULL)
28 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
29 #define fdt_size_to_cpu(reg) be64_to_cpu(reg)
30 #else
31 typedef u32 fdt_addr_t;
32 typedef u32 fdt_size_t;
33 #define FDT_ADDR_T_NONE (-1U)
34 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
35 #define fdt_size_to_cpu(reg) be32_to_cpu(reg)
36 #endif
37 
38 /* Information obtained about memory from the FDT */
39 struct fdt_memory {
40 	fdt_addr_t start;
41 	fdt_addr_t end;
42 };
43 
44 /*
45  * Information about a resource. start is the first address of the resource
46  * and end is the last address (inclusive). The length of the resource will
47  * be equal to: end - start + 1.
48  */
49 struct fdt_resource {
50 	fdt_addr_t start;
51 	fdt_addr_t end;
52 };
53 
54 enum fdt_pci_space {
55 	FDT_PCI_SPACE_CONFIG = 0,
56 	FDT_PCI_SPACE_IO = 0x01000000,
57 	FDT_PCI_SPACE_MEM32 = 0x02000000,
58 	FDT_PCI_SPACE_MEM64 = 0x03000000,
59 	FDT_PCI_SPACE_MEM32_PREF = 0x42000000,
60 	FDT_PCI_SPACE_MEM64_PREF = 0x43000000,
61 };
62 
63 #define FDT_PCI_ADDR_CELLS	3
64 #define FDT_PCI_SIZE_CELLS	2
65 #define FDT_PCI_REG_SIZE	\
66 	((FDT_PCI_ADDR_CELLS + FDT_PCI_SIZE_CELLS) * sizeof(u32))
67 
68 /*
69  * The Open Firmware spec defines PCI physical address as follows:
70  *
71  *          bits# 31 .... 24 23 .... 16 15 .... 08 07 .... 00
72  *
73  * phys.hi  cell:  npt000ss   bbbbbbbb   dddddfff   rrrrrrrr
74  * phys.mid cell:  hhhhhhhh   hhhhhhhh   hhhhhhhh   hhhhhhhh
75  * phys.lo  cell:  llllllll   llllllll   llllllll   llllllll
76  *
77  * where:
78  *
79  * n:        is 0 if the address is relocatable, 1 otherwise
80  * p:        is 1 if addressable region is prefetchable, 0 otherwise
81  * t:        is 1 if the address is aliased (for non-relocatable I/O) below 1MB
82  *           (for Memory), or below 64KB (for relocatable I/O)
83  * ss:       is the space code, denoting the address space
84  * bbbbbbbb: is the 8-bit Bus Number
85  * ddddd:    is the 5-bit Device Number
86  * fff:      is the 3-bit Function Number
87  * rrrrrrrr: is the 8-bit Register Number
88  * hhhhhhhh: is a 32-bit unsigned number
89  * llllllll: is a 32-bit unsigned number
90  */
91 struct fdt_pci_addr {
92 	u32	phys_hi;
93 	u32	phys_mid;
94 	u32	phys_lo;
95 };
96 
97 /**
98  * Compute the size of a resource.
99  *
100  * @param res	the resource to operate on
101  * @return the size of the resource
102  */
103 static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
104 {
105 	return res->end - res->start + 1;
106 }
107 
108 /**
109  * Compat types that we know about and for which we might have drivers.
110  * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
111  * within drivers.
112  */
113 enum fdt_compat_id {
114 	COMPAT_UNKNOWN,
115 	COMPAT_NVIDIA_TEGRA20_USB,	/* Tegra20 USB port */
116 	COMPAT_NVIDIA_TEGRA30_USB,	/* Tegra30 USB port */
117 	COMPAT_NVIDIA_TEGRA114_USB,	/* Tegra114 USB port */
118 	COMPAT_NVIDIA_TEGRA20_EMC,	/* Tegra20 memory controller */
119 	COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
120 	COMPAT_NVIDIA_TEGRA20_KBC,	/* Tegra20 Keyboard */
121 	COMPAT_NVIDIA_TEGRA20_NAND,	/* Tegra2 NAND controller */
122 	COMPAT_NVIDIA_TEGRA20_PWM,	/* Tegra 2 PWM controller */
123 	COMPAT_NVIDIA_TEGRA20_DC,	/* Tegra 2 Display controller */
124 	COMPAT_NVIDIA_TEGRA124_SDMMC,	/* Tegra124 SDMMC controller */
125 	COMPAT_NVIDIA_TEGRA30_SDMMC,	/* Tegra30 SDMMC controller */
126 	COMPAT_NVIDIA_TEGRA20_SDMMC,	/* Tegra20 SDMMC controller */
127 	COMPAT_NVIDIA_TEGRA124_PCIE,	/* Tegra 124 PCIe controller */
128 	COMPAT_NVIDIA_TEGRA30_PCIE,	/* Tegra 30 PCIe controller */
129 	COMPAT_NVIDIA_TEGRA20_PCIE,	/* Tegra 20 PCIe controller */
130 	COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
131 					/* Tegra124 XUSB pad controller */
132 	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
133 	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
134 	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */
135 	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
136 	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */
137 	COMPAT_GOOGLE_CROS_EC,		/* Google CROS_EC Protocol */
138 	COMPAT_GOOGLE_CROS_EC_KEYB,	/* Google CROS_EC Keyboard */
139 	COMPAT_SAMSUNG_EXYNOS_EHCI,	/* Exynos EHCI controller */
140 	COMPAT_SAMSUNG_EXYNOS5_XHCI,	/* Exynos5 XHCI controller */
141 	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */
142 	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
143 	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */
144 	COMPAT_SAMSUNG_EXYNOS_FIMD,	/* Exynos Display controller */
145 	COMPAT_SAMSUNG_EXYNOS_MIPI_DSI,	/* Exynos mipi dsi */
146 	COMPAT_SAMSUNG_EXYNOS5_DP,	/* Exynos Display port controller */
147 	COMPAT_SAMSUNG_EXYNOS_DWMMC,	/* Exynos DWMMC controller */
148 	COMPAT_SAMSUNG_EXYNOS_MMC,	/* Exynos MMC controller */
149 	COMPAT_SAMSUNG_EXYNOS_SERIAL,	/* Exynos UART */
150 	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */
151 	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */
152 	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */
153 	COMPAT_INFINEON_SLB9635_TPM,	/* Infineon SLB9635 TPM */
154 	COMPAT_INFINEON_SLB9645_TPM,	/* Infineon SLB9645 TPM */
155 	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */
156 	COMPAT_SANDBOX_HOST_EMULATION,	/* Sandbox emulation of a function */
157 	COMPAT_SANDBOX_LCD_SDL,		/* Sandbox LCD emulation with SDL */
158 	COMPAT_TI_TPS65090,		/* Texas Instrument TPS65090 */
159 	COMPAT_NXP_PTN3460,		/* NXP PTN3460 DP/LVDS bridge */
160 	COMPAT_SAMSUNG_EXYNOS_SYSMMU,	/* Exynos sysmmu */
161 	COMPAT_PARADE_PS8625,		/* Parade PS8622 EDP->LVDS bridge */
162 	COMPAT_INTEL_LPC,		/* Intel Low Pin Count I/F */
163 	COMPAT_INTEL_MICROCODE,		/* Intel microcode update */
164 	COMPAT_MEMORY_SPD,		/* Memory SPD information */
165 	COMPAT_INTEL_PANTHERPOINT_AHCI,	/* Intel Pantherpoint AHCI */
166 	COMPAT_INTEL_MODEL_206AX,	/* Intel Model 206AX CPU */
167 	COMPAT_INTEL_GMA,		/* Intel Graphics Media Accelerator */
168 	COMPAT_AMS_AS3722,		/* AMS AS3722 PMIC */
169 	COMPAT_INTEL_ICH_SPI,		/* Intel ICH7/9 SPI controller */
170 	COMPAT_INTEL_QRK_MRC,		/* Intel Quark MRC */
171 	COMPAT_SOCIONEXT_XHCI,		/* Socionext UniPhier xHCI */
172 
173 	COMPAT_COUNT,
174 };
175 
176 #define MAX_PHANDLE_ARGS 16
177 struct fdtdec_phandle_args {
178 	int node;
179 	int args_count;
180 	uint32_t args[MAX_PHANDLE_ARGS];
181 };
182 
183 /**
184  * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
185  *
186  * This function is useful to parse lists of phandles and their arguments.
187  *
188  * Example:
189  *
190  * phandle1: node1 {
191  *	#list-cells = <2>;
192  * }
193  *
194  * phandle2: node2 {
195  *	#list-cells = <1>;
196  * }
197  *
198  * node3 {
199  *	list = <&phandle1 1 2 &phandle2 3>;
200  * }
201  *
202  * To get a device_node of the `node2' node you may call this:
203  * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
204  *				  &args);
205  *
206  * (This function is a modified version of __of_parse_phandle_with_args() from
207  * Linux 3.18)
208  *
209  * @blob:	Pointer to device tree
210  * @src_node:	Offset of device tree node containing a list
211  * @list_name:	property name that contains a list
212  * @cells_name:	property name that specifies the phandles' arguments count,
213  *		or NULL to use @cells_count
214  * @cells_count: Cell count to use if @cells_name is NULL
215  * @index:	index of a phandle to parse out
216  * @out_args:	optional pointer to output arguments structure (will be filled)
217  * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
218  *	@list_name does not exist, a phandle was not found, @cells_name
219  *	could not be found, the arguments were truncated or there were too
220  *	many arguments.
221  *
222  */
223 int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
224 				   const char *list_name,
225 				   const char *cells_name,
226 				   int cell_count, int index,
227 				   struct fdtdec_phandle_args *out_args);
228 
229 /**
230  * Find the next numbered alias for a peripheral. This is used to enumerate
231  * all the peripherals of a certain type.
232  *
233  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
234  * this function will return a pointer to the node the alias points to, and
235  * then update *upto to 1. Next time you call this function, the next node
236  * will be returned.
237  *
238  * All nodes returned will match the compatible ID, as it is assumed that
239  * all peripherals use the same driver.
240  *
241  * @param blob		FDT blob to use
242  * @param name		Root name of alias to search for
243  * @param id		Compatible ID to look for
244  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
245  */
246 int fdtdec_next_alias(const void *blob, const char *name,
247 		enum fdt_compat_id id, int *upto);
248 
249 /**
250  * Find the compatible ID for a given node.
251  *
252  * Generally each node has at least one compatible string attached to it.
253  * This function looks through our list of known compatible strings and
254  * returns the corresponding ID which matches the compatible string.
255  *
256  * @param blob		FDT blob to use
257  * @param node		Node containing compatible string to find
258  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
259  */
260 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
261 
262 /**
263  * Find the next compatible node for a peripheral.
264  *
265  * Do the first call with node = 0. This function will return a pointer to
266  * the next compatible node. Next time you call this function, pass the
267  * value returned, and the next node will be provided.
268  *
269  * @param blob		FDT blob to use
270  * @param node		Start node for search
271  * @param id		Compatible ID to look for (enum fdt_compat_id)
272  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
273  */
274 int fdtdec_next_compatible(const void *blob, int node,
275 		enum fdt_compat_id id);
276 
277 /**
278  * Find the next compatible subnode for a peripheral.
279  *
280  * Do the first call with node set to the parent and depth = 0. This
281  * function will return the offset of the next compatible node. Next time
282  * you call this function, pass the node value returned last time, with
283  * depth unchanged, and the next node will be provided.
284  *
285  * @param blob		FDT blob to use
286  * @param node		Start node for search
287  * @param id		Compatible ID to look for (enum fdt_compat_id)
288  * @param depthp	Current depth (set to 0 before first call)
289  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
290  */
291 int fdtdec_next_compatible_subnode(const void *blob, int node,
292 		enum fdt_compat_id id, int *depthp);
293 
294 /**
295  * Look up an address property in a node and return it as an address.
296  * The property must hold either one address with no trailing data or
297  * one address with a length. This is only tested on 32-bit machines.
298  *
299  * @param blob	FDT blob
300  * @param node	node to examine
301  * @param prop_name	name of property to find
302  * @return address, if found, or FDT_ADDR_T_NONE if not
303  */
304 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
305 		const char *prop_name);
306 
307 /**
308  * Look up an address property in a node and return it as an address.
309  * The property must hold one address with a length. This is only tested
310  * on 32-bit machines.
311  *
312  * @param blob	FDT blob
313  * @param node	node to examine
314  * @param prop_name	name of property to find
315  * @return address, if found, or FDT_ADDR_T_NONE if not
316  */
317 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
318 		const char *prop_name, fdt_size_t *sizep);
319 
320 /**
321  * Look at an address property in a node and return the pci address which
322  * corresponds to the given type in the form of fdt_pci_addr.
323  * The property must hold one fdt_pci_addr with a lengh.
324  *
325  * @param blob		FDT blob
326  * @param node		node to examine
327  * @param type		pci address type (FDT_PCI_SPACE_xxx)
328  * @param prop_name	name of property to find
329  * @param addr		returns pci address in the form of fdt_pci_addr
330  * @return 0 if ok, negative on error
331  */
332 int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
333 		const char *prop_name, struct fdt_pci_addr *addr);
334 
335 /**
336  * Look at the compatible property of a device node that represents a PCI
337  * device and extract pci vendor id and device id from it.
338  *
339  * @param blob		FDT blob
340  * @param node		node to examine
341  * @param vendor	vendor id of the pci device
342  * @param device	device id of the pci device
343  * @return 0 if ok, negative on error
344  */
345 int fdtdec_get_pci_vendev(const void *blob, int node,
346 		u16 *vendor, u16 *device);
347 
348 /**
349  * Look at the pci address of a device node that represents a PCI device
350  * and parse the bus, device and function number from it. For some cases
351  * like the bus number encoded in reg property is not correct after pci
352  * enumeration, this function looks through the node's compatible strings
353  * to get these numbers extracted instead.
354  *
355  * @param blob		FDT blob
356  * @param node		node to examine
357  * @param addr		pci address in the form of fdt_pci_addr
358  * @param bdf		returns bus, device, function triplet
359  * @return 0 if ok, negative on error
360  */
361 int fdtdec_get_pci_bdf(const void *blob, int node,
362 		struct fdt_pci_addr *addr, pci_dev_t *bdf);
363 
364 /**
365  * Look at the pci address of a device node that represents a PCI device
366  * and return base address of the pci device's registers.
367  *
368  * @param blob		FDT blob
369  * @param node		node to examine
370  * @param addr		pci address in the form of fdt_pci_addr
371  * @param bar		returns base address of the pci device's registers
372  * @return 0 if ok, negative on error
373  */
374 int fdtdec_get_pci_bar32(const void *blob, int node,
375 		struct fdt_pci_addr *addr, u32 *bar);
376 
377 /**
378  * Look up a 32-bit integer property in a node and return it. The property
379  * must have at least 4 bytes of data. The value of the first cell is
380  * returned.
381  *
382  * @param blob	FDT blob
383  * @param node	node to examine
384  * @param prop_name	name of property to find
385  * @param default_val	default value to return if the property is not found
386  * @return integer value, if found, or default_val if not
387  */
388 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
389 		s32 default_val);
390 
391 /**
392  * Look up a 64-bit integer property in a node and return it. The property
393  * must have at least 8 bytes of data (2 cells). The first two cells are
394  * concatenated to form a 8 bytes value, where the first cell is top half and
395  * the second cell is bottom half.
396  *
397  * @param blob	FDT blob
398  * @param node	node to examine
399  * @param prop_name	name of property to find
400  * @param default_val	default value to return if the property is not found
401  * @return integer value, if found, or default_val if not
402  */
403 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
404 		uint64_t default_val);
405 
406 /**
407  * Checks whether a node is enabled.
408  * This looks for a 'status' property. If this exists, then returns 1 if
409  * the status is 'ok' and 0 otherwise. If there is no status property,
410  * it returns 1 on the assumption that anything mentioned should be enabled
411  * by default.
412  *
413  * @param blob	FDT blob
414  * @param node	node to examine
415  * @return integer value 0 (not enabled) or 1 (enabled)
416  */
417 int fdtdec_get_is_enabled(const void *blob, int node);
418 
419 /**
420  * Make sure we have a valid fdt available to control U-Boot.
421  *
422  * If not, a message is printed to the console if the console is ready.
423  *
424  * @return 0 if all ok, -1 if not
425  */
426 int fdtdec_prepare_fdt(void);
427 
428 /**
429  * Checks that we have a valid fdt available to control U-Boot.
430 
431  * However, if not then for the moment nothing is done, since this function
432  * is called too early to panic().
433  *
434  * @returns 0
435  */
436 int fdtdec_check_fdt(void);
437 
438 /**
439  * Find the nodes for a peripheral and return a list of them in the correct
440  * order. This is used to enumerate all the peripherals of a certain type.
441  *
442  * To use this, optionally set up a /aliases node with alias properties for
443  * a peripheral. For example, for usb you could have:
444  *
445  * aliases {
446  *		usb0 = "/ehci@c5008000";
447  *		usb1 = "/ehci@c5000000";
448  * };
449  *
450  * Pass "usb" as the name to this function and will return a list of two
451  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
452  *
453  * All nodes returned will match the compatible ID, as it is assumed that
454  * all peripherals use the same driver.
455  *
456  * If no alias node is found, then the node list will be returned in the
457  * order found in the fdt. If the aliases mention a node which doesn't
458  * exist, then this will be ignored. If nodes are found with no aliases,
459  * they will be added in any order.
460  *
461  * If there is a gap in the aliases, then this function return a 0 node at
462  * that position. The return value will also count these gaps.
463  *
464  * This function checks node properties and will not return nodes which are
465  * marked disabled (status = "disabled").
466  *
467  * @param blob		FDT blob to use
468  * @param name		Root name of alias to search for
469  * @param id		Compatible ID to look for
470  * @param node_list	Place to put list of found nodes
471  * @param maxcount	Maximum number of nodes to find
472  * @return number of nodes found on success, FTD_ERR_... on error
473  */
474 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
475 			enum fdt_compat_id id, int *node_list, int maxcount);
476 
477 /*
478  * This function is similar to fdtdec_find_aliases_for_id() except that it
479  * adds to the node_list that is passed in. Any 0 elements are considered
480  * available for allocation - others are considered already used and are
481  * skipped.
482  *
483  * You can use this by calling fdtdec_find_aliases_for_id() with an
484  * uninitialised array, then setting the elements that are returned to -1,
485  * say, then calling this function, perhaps with a different compat id.
486  * Any elements you get back that are >0 are new nodes added by the call
487  * to this function.
488  *
489  * Note that if you have some nodes with aliases and some without, you are
490  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
491  * one compat_id may fill in positions for which you have aliases defined
492  * for another compat_id. When you later call *this* function with the second
493  * compat_id, the alias positions may already be used. A debug warning may
494  * be generated in this case, but it is safest to define aliases for all
495  * nodes when you care about the ordering.
496  */
497 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
498 			enum fdt_compat_id id, int *node_list, int maxcount);
499 
500 /**
501  * Get the alias sequence number of a node
502  *
503  * This works out whether a node is pointed to by an alias, and if so, the
504  * sequence number of that alias. Aliases are of the form <base><num> where
505  * <num> is the sequence number. For example spi2 would be sequence number
506  * 2.
507  *
508  * @param blob		Device tree blob (if NULL, then error is returned)
509  * @param base		Base name for alias (before the underscore)
510  * @param node		Node to look up
511  * @param seqp		This is set to the sequence number if one is found,
512  *			but otherwise the value is left alone
513  * @return 0 if a sequence was found, -ve if not
514  */
515 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
516 			 int *seqp);
517 
518 /**
519  * Get the offset of the given chosen node
520  *
521  * This looks up a property in /chosen containing the path to another node,
522  * then finds the offset of that node.
523  *
524  * @param blob		Device tree blob (if NULL, then error is returned)
525  * @param name		Property name, e.g. "stdout-path"
526  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
527  */
528 int fdtdec_get_chosen_node(const void *blob, const char *name);
529 
530 /*
531  * Get the name for a compatible ID
532  *
533  * @param id		Compatible ID to look for
534  * @return compatible string for that id
535  */
536 const char *fdtdec_get_compatible(enum fdt_compat_id id);
537 
538 /* Look up a phandle and follow it to its node. Then return the offset
539  * of that node.
540  *
541  * @param blob		FDT blob
542  * @param node		node to examine
543  * @param prop_name	name of property to find
544  * @return node offset if found, -ve error code on error
545  */
546 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
547 
548 /**
549  * Look up a property in a node and return its contents in an integer
550  * array of given length. The property must have at least enough data for
551  * the array (4*count bytes). It may have more, but this will be ignored.
552  *
553  * @param blob		FDT blob
554  * @param node		node to examine
555  * @param prop_name	name of property to find
556  * @param array		array to fill with data
557  * @param count		number of array elements
558  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
559  *		or -FDT_ERR_BADLAYOUT if not enough data
560  */
561 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
562 		u32 *array, int count);
563 
564 /**
565  * Look up a property in a node and return its contents in an integer
566  * array of given length. The property must exist but may have less data that
567  * expected (4*count bytes). It may have more, but this will be ignored.
568  *
569  * @param blob		FDT blob
570  * @param node		node to examine
571  * @param prop_name	name of property to find
572  * @param array		array to fill with data
573  * @param count		number of array elements
574  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
575  *		property is not found
576  */
577 int fdtdec_get_int_array_count(const void *blob, int node,
578 			       const char *prop_name, u32 *array, int count);
579 
580 /**
581  * Look up a property in a node and return a pointer to its contents as a
582  * unsigned int array of given length. The property must have at least enough
583  * data for the array ('count' cells). It may have more, but this will be
584  * ignored. The data is not copied.
585  *
586  * Note that you must access elements of the array with fdt32_to_cpu(),
587  * since the elements will be big endian even on a little endian machine.
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 array if found, or NULL if the property is not
594  *		found or there is not enough data
595  */
596 const u32 *fdtdec_locate_array(const void *blob, int node,
597 			       const char *prop_name, int count);
598 
599 /**
600  * Look up a boolean property in a node and return it.
601  *
602  * A boolean properly is true if present in the device tree and false if not
603  * present, regardless of its value.
604  *
605  * @param blob	FDT blob
606  * @param node	node to examine
607  * @param prop_name	name of property to find
608  * @return 1 if the properly is present; 0 if it isn't present
609  */
610 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
611 
612 /**
613  * Look in the FDT for a config item with the given name and return its value
614  * as a 32-bit integer. The property must have at least 4 bytes of data. The
615  * value of the first cell is returned.
616  *
617  * @param blob		FDT blob to use
618  * @param prop_name	Node property name
619  * @param default_val	default value to return if the property is not found
620  * @return integer value, if found, or default_val if not
621  */
622 int fdtdec_get_config_int(const void *blob, const char *prop_name,
623 		int default_val);
624 
625 /**
626  * Look in the FDT for a config item with the given name
627  * and return whether it exists.
628  *
629  * @param blob		FDT blob
630  * @param prop_name	property name to look up
631  * @return 1, if it exists, or 0 if not
632  */
633 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
634 
635 /**
636  * Look in the FDT for a config item with the given name and return its value
637  * as a string.
638  *
639  * @param blob          FDT blob
640  * @param prop_name     property name to look up
641  * @returns property string, NULL on error.
642  */
643 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
644 
645 /*
646  * Look up a property in a node and return its contents in a byte
647  * array of given length. The property must have at least enough data for
648  * the array (count bytes). It may have more, but this will be ignored.
649  *
650  * @param blob		FDT blob
651  * @param node		node to examine
652  * @param prop_name	name of property to find
653  * @param array		array to fill with data
654  * @param count		number of array elements
655  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
656  *		or -FDT_ERR_BADLAYOUT if not enough data
657  */
658 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
659 		u8 *array, int count);
660 
661 /**
662  * Look up a property in a node and return a pointer to its contents as a
663  * byte array of given length. The property must have at least enough data
664  * for the array (count bytes). It may have more, but this will be ignored.
665  * The data is not copied.
666  *
667  * @param blob		FDT blob
668  * @param node		node to examine
669  * @param prop_name	name of property to find
670  * @param count		number of array elements
671  * @return pointer to byte array if found, or NULL if the property is not
672  *		found or there is not enough data
673  */
674 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
675 			     const char *prop_name, int count);
676 
677 /**
678  * Look up a property in a node which contains a memory region address and
679  * size. Then return a pointer to this address.
680  *
681  * The property must hold one address with a length. This is only tested on
682  * 32-bit machines.
683  *
684  * @param blob		FDT blob
685  * @param node		node to examine
686  * @param prop_name	name of property to find
687  * @param basep		Returns base address of region
688  * @param size		Returns size of region
689  * @return 0 if ok, -1 on error (property not found)
690  */
691 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
692 			 fdt_addr_t *basep, fdt_size_t *sizep);
693 
694 enum fmap_compress_t {
695 	FMAP_COMPRESS_NONE,
696 	FMAP_COMPRESS_LZO,
697 };
698 
699 enum fmap_hash_t {
700 	FMAP_HASH_NONE,
701 	FMAP_HASH_SHA1,
702 	FMAP_HASH_SHA256,
703 };
704 
705 /* A flash map entry, containing an offset and length */
706 struct fmap_entry {
707 	uint32_t offset;
708 	uint32_t length;
709 	uint32_t used;			/* Number of bytes used in region */
710 	enum fmap_compress_t compress_algo;	/* Compression type */
711 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
712 	const uint8_t *hash;			/* Hash value */
713 	int hash_size;				/* Hash size */
714 };
715 
716 /**
717  * Read a flash entry from the fdt
718  *
719  * @param blob		FDT blob
720  * @param node		Offset of node to read
721  * @param name		Name of node being read
722  * @param entry		Place to put offset and size of this node
723  * @return 0 if ok, -ve on error
724  */
725 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
726 			   struct fmap_entry *entry);
727 
728 /**
729  * Obtain an indexed resource from a device property.
730  *
731  * @param fdt		FDT blob
732  * @param node		node to examine
733  * @param property	name of the property to parse
734  * @param index		index of the resource to retrieve
735  * @param res		returns the resource
736  * @return 0 if ok, negative on error
737  */
738 int fdt_get_resource(const void *fdt, int node, const char *property,
739 		     unsigned int index, struct fdt_resource *res);
740 
741 /**
742  * Obtain a named resource from a device property.
743  *
744  * Look up the index of the name in a list of strings and return the resource
745  * at that index.
746  *
747  * @param fdt		FDT blob
748  * @param node		node to examine
749  * @param property	name of the property to parse
750  * @param prop_names	name of the property containing the list of names
751  * @param name		the name of the entry to look up
752  * @param res		returns the resource
753  */
754 int fdt_get_named_resource(const void *fdt, int node, const char *property,
755 			   const char *prop_names, const char *name,
756 			   struct fdt_resource *res);
757 
758 /**
759  * Decode a named region within a memory bank of a given type.
760  *
761  * This function handles selection of a memory region. The region is
762  * specified as an offset/size within a particular type of memory.
763  *
764  * The properties used are:
765  *
766  *	<mem_type>-memory<suffix> for the name of the memory bank
767  *	<mem_type>-offset<suffix> for the offset in that bank
768  *
769  * The property value must have an offset and a size. The function checks
770  * that the region is entirely within the memory bank.5
771  *
772  * @param blob		FDT blob
773  * @param node		Node containing the properties (-1 for /config)
774  * @param mem_type	Type of memory to use, which is a name, such as
775  *			"u-boot" or "kernel".
776  * @param suffix	String to append to the memory/offset
777  *			property names
778  * @param basep		Returns base of region
779  * @param sizep		Returns size of region
780  * @return 0 if OK, -ive on error
781  */
782 int fdtdec_decode_memory_region(const void *blob, int node,
783 				const char *mem_type, const char *suffix,
784 				fdt_addr_t *basep, fdt_size_t *sizep);
785 #endif
786