xref: /openbmc/u-boot/include/fdtdec.h (revision f13606b7)
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 
172 	COMPAT_COUNT,
173 };
174 
175 #define MAX_PHANDLE_ARGS 16
176 struct fdtdec_phandle_args {
177 	int node;
178 	int args_count;
179 	uint32_t args[MAX_PHANDLE_ARGS];
180 };
181 
182 /**
183  * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
184  *
185  * This function is useful to parse lists of phandles and their arguments.
186  *
187  * Example:
188  *
189  * phandle1: node1 {
190  *	#list-cells = <2>;
191  * }
192  *
193  * phandle2: node2 {
194  *	#list-cells = <1>;
195  * }
196  *
197  * node3 {
198  *	list = <&phandle1 1 2 &phandle2 3>;
199  * }
200  *
201  * To get a device_node of the `node2' node you may call this:
202  * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
203  *				  &args);
204  *
205  * (This function is a modified version of __of_parse_phandle_with_args() from
206  * Linux 3.18)
207  *
208  * @blob:	Pointer to device tree
209  * @src_node:	Offset of device tree node containing a list
210  * @list_name:	property name that contains a list
211  * @cells_name:	property name that specifies the phandles' arguments count,
212  *		or NULL to use @cells_count
213  * @cells_count: Cell count to use if @cells_name is NULL
214  * @index:	index of a phandle to parse out
215  * @out_args:	optional pointer to output arguments structure (will be filled)
216  * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
217  *	@list_name does not exist, a phandle was not found, @cells_name
218  *	could not be found, the arguments were truncated or there were too
219  *	many arguments.
220  *
221  */
222 int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
223 				   const char *list_name,
224 				   const char *cells_name,
225 				   int cell_count, int index,
226 				   struct fdtdec_phandle_args *out_args);
227 
228 /**
229  * Find the next numbered alias for a peripheral. This is used to enumerate
230  * all the peripherals of a certain type.
231  *
232  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
233  * this function will return a pointer to the node the alias points to, and
234  * then update *upto to 1. Next time you call this function, the next node
235  * will be returned.
236  *
237  * All nodes returned will match the compatible ID, as it is assumed that
238  * all peripherals use the same driver.
239  *
240  * @param blob		FDT blob to use
241  * @param name		Root name of alias to search for
242  * @param id		Compatible ID to look for
243  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
244  */
245 int fdtdec_next_alias(const void *blob, const char *name,
246 		enum fdt_compat_id id, int *upto);
247 
248 /**
249  * Find the compatible ID for a given node.
250  *
251  * Generally each node has at least one compatible string attached to it.
252  * This function looks through our list of known compatible strings and
253  * returns the corresponding ID which matches the compatible string.
254  *
255  * @param blob		FDT blob to use
256  * @param node		Node containing compatible string to find
257  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
258  */
259 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
260 
261 /**
262  * Find the next compatible node for a peripheral.
263  *
264  * Do the first call with node = 0. This function will return a pointer to
265  * the next compatible node. Next time you call this function, pass the
266  * value returned, and the next node will be provided.
267  *
268  * @param blob		FDT blob to use
269  * @param node		Start node for search
270  * @param id		Compatible ID to look for (enum fdt_compat_id)
271  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
272  */
273 int fdtdec_next_compatible(const void *blob, int node,
274 		enum fdt_compat_id id);
275 
276 /**
277  * Find the next compatible subnode for a peripheral.
278  *
279  * Do the first call with node set to the parent and depth = 0. This
280  * function will return the offset of the next compatible node. Next time
281  * you call this function, pass the node value returned last time, with
282  * depth unchanged, and the next node will be provided.
283  *
284  * @param blob		FDT blob to use
285  * @param node		Start node for search
286  * @param id		Compatible ID to look for (enum fdt_compat_id)
287  * @param depthp	Current depth (set to 0 before first call)
288  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
289  */
290 int fdtdec_next_compatible_subnode(const void *blob, int node,
291 		enum fdt_compat_id id, int *depthp);
292 
293 /**
294  * Look up an address property in a node and return it as an address.
295  * The property must hold either one address with no trailing data or
296  * one address with a length. This is only tested on 32-bit machines.
297  *
298  * @param blob	FDT blob
299  * @param node	node to examine
300  * @param prop_name	name of property to find
301  * @return address, if found, or FDT_ADDR_T_NONE if not
302  */
303 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
304 		const char *prop_name);
305 
306 /**
307  * Look up an address property in a node and return it as an address.
308  * The property must hold one address with a length. This is only tested
309  * on 32-bit machines.
310  *
311  * @param blob	FDT blob
312  * @param node	node to examine
313  * @param prop_name	name of property to find
314  * @return address, if found, or FDT_ADDR_T_NONE if not
315  */
316 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
317 		const char *prop_name, fdt_size_t *sizep);
318 
319 /**
320  * Look at an address property in a node and return the pci address which
321  * corresponds to the given type in the form of fdt_pci_addr.
322  * The property must hold one fdt_pci_addr with a lengh.
323  *
324  * @param blob		FDT blob
325  * @param node		node to examine
326  * @param type		pci address type (FDT_PCI_SPACE_xxx)
327  * @param prop_name	name of property to find
328  * @param addr		returns pci address in the form of fdt_pci_addr
329  * @return 0 if ok, negative on error
330  */
331 int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
332 		const char *prop_name, struct fdt_pci_addr *addr);
333 
334 /**
335  * Look at the compatible property of a device node that represents a PCI
336  * device and extract pci vendor id and device id from it.
337  *
338  * @param blob		FDT blob
339  * @param node		node to examine
340  * @param vendor	vendor id of the pci device
341  * @param device	device id of the pci device
342  * @return 0 if ok, negative on error
343  */
344 int fdtdec_get_pci_vendev(const void *blob, int node,
345 		u16 *vendor, u16 *device);
346 
347 /**
348  * Look at the pci address of a device node that represents a PCI device
349  * and parse the bus, device and function number from it.
350  *
351  * @param blob		FDT blob
352  * @param node		node to examine
353  * @param addr		pci address in the form of fdt_pci_addr
354  * @param bdf		returns bus, device, function triplet
355  * @return 0 if ok, negative on error
356  */
357 int fdtdec_get_pci_bdf(const void *blob, int node,
358 		struct fdt_pci_addr *addr, pci_dev_t *bdf);
359 
360 /**
361  * Look at the pci address of a device node that represents a PCI device
362  * and return base address of the pci device's registers.
363  *
364  * @param blob		FDT blob
365  * @param node		node to examine
366  * @param addr		pci address in the form of fdt_pci_addr
367  * @param bar		returns base address of the pci device's registers
368  * @return 0 if ok, negative on error
369  */
370 int fdtdec_get_pci_bar32(const void *blob, int node,
371 		struct fdt_pci_addr *addr, u32 *bar);
372 
373 /**
374  * Look up a 32-bit integer property in a node and return it. The property
375  * must have at least 4 bytes of data. The value of the first cell is
376  * returned.
377  *
378  * @param blob	FDT blob
379  * @param node	node to examine
380  * @param prop_name	name of property to find
381  * @param default_val	default value to return if the property is not found
382  * @return integer value, if found, or default_val if not
383  */
384 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
385 		s32 default_val);
386 
387 /**
388  * Look up a 64-bit integer property in a node and return it. The property
389  * must have at least 8 bytes of data (2 cells). The first two cells are
390  * concatenated to form a 8 bytes value, where the first cell is top half and
391  * the second cell is bottom half.
392  *
393  * @param blob	FDT blob
394  * @param node	node to examine
395  * @param prop_name	name of property to find
396  * @param default_val	default value to return if the property is not found
397  * @return integer value, if found, or default_val if not
398  */
399 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
400 		uint64_t default_val);
401 
402 /**
403  * Checks whether a node is enabled.
404  * This looks for a 'status' property. If this exists, then returns 1 if
405  * the status is 'ok' and 0 otherwise. If there is no status property,
406  * it returns 1 on the assumption that anything mentioned should be enabled
407  * by default.
408  *
409  * @param blob	FDT blob
410  * @param node	node to examine
411  * @return integer value 0 (not enabled) or 1 (enabled)
412  */
413 int fdtdec_get_is_enabled(const void *blob, int node);
414 
415 /**
416  * Make sure we have a valid fdt available to control U-Boot.
417  *
418  * If not, a message is printed to the console if the console is ready.
419  *
420  * @return 0 if all ok, -1 if not
421  */
422 int fdtdec_prepare_fdt(void);
423 
424 /**
425  * Checks that we have a valid fdt available to control U-Boot.
426 
427  * However, if not then for the moment nothing is done, since this function
428  * is called too early to panic().
429  *
430  * @returns 0
431  */
432 int fdtdec_check_fdt(void);
433 
434 /**
435  * Find the nodes for a peripheral and return a list of them in the correct
436  * order. This is used to enumerate all the peripherals of a certain type.
437  *
438  * To use this, optionally set up a /aliases node with alias properties for
439  * a peripheral. For example, for usb you could have:
440  *
441  * aliases {
442  *		usb0 = "/ehci@c5008000";
443  *		usb1 = "/ehci@c5000000";
444  * };
445  *
446  * Pass "usb" as the name to this function and will return a list of two
447  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
448  *
449  * All nodes returned will match the compatible ID, as it is assumed that
450  * all peripherals use the same driver.
451  *
452  * If no alias node is found, then the node list will be returned in the
453  * order found in the fdt. If the aliases mention a node which doesn't
454  * exist, then this will be ignored. If nodes are found with no aliases,
455  * they will be added in any order.
456  *
457  * If there is a gap in the aliases, then this function return a 0 node at
458  * that position. The return value will also count these gaps.
459  *
460  * This function checks node properties and will not return nodes which are
461  * marked disabled (status = "disabled").
462  *
463  * @param blob		FDT blob to use
464  * @param name		Root name of alias to search for
465  * @param id		Compatible ID to look for
466  * @param node_list	Place to put list of found nodes
467  * @param maxcount	Maximum number of nodes to find
468  * @return number of nodes found on success, FTD_ERR_... on error
469  */
470 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
471 			enum fdt_compat_id id, int *node_list, int maxcount);
472 
473 /*
474  * This function is similar to fdtdec_find_aliases_for_id() except that it
475  * adds to the node_list that is passed in. Any 0 elements are considered
476  * available for allocation - others are considered already used and are
477  * skipped.
478  *
479  * You can use this by calling fdtdec_find_aliases_for_id() with an
480  * uninitialised array, then setting the elements that are returned to -1,
481  * say, then calling this function, perhaps with a different compat id.
482  * Any elements you get back that are >0 are new nodes added by the call
483  * to this function.
484  *
485  * Note that if you have some nodes with aliases and some without, you are
486  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
487  * one compat_id may fill in positions for which you have aliases defined
488  * for another compat_id. When you later call *this* function with the second
489  * compat_id, the alias positions may already be used. A debug warning may
490  * be generated in this case, but it is safest to define aliases for all
491  * nodes when you care about the ordering.
492  */
493 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
494 			enum fdt_compat_id id, int *node_list, int maxcount);
495 
496 /**
497  * Get the alias sequence number of a node
498  *
499  * This works out whether a node is pointed to by an alias, and if so, the
500  * sequence number of that alias. Aliases are of the form <base><num> where
501  * <num> is the sequence number. For example spi2 would be sequence number
502  * 2.
503  *
504  * @param blob		Device tree blob (if NULL, then error is returned)
505  * @param base		Base name for alias (before the underscore)
506  * @param node		Node to look up
507  * @param seqp		This is set to the sequence number if one is found,
508  *			but otherwise the value is left alone
509  * @return 0 if a sequence was found, -ve if not
510  */
511 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
512 			 int *seqp);
513 
514 /**
515  * Get the offset of the given chosen node
516  *
517  * This looks up a property in /chosen containing the path to another node,
518  * then finds the offset of that node.
519  *
520  * @param blob		Device tree blob (if NULL, then error is returned)
521  * @param name		Property name, e.g. "stdout-path"
522  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
523  */
524 int fdtdec_get_chosen_node(const void *blob, const char *name);
525 
526 /*
527  * Get the name for a compatible ID
528  *
529  * @param id		Compatible ID to look for
530  * @return compatible string for that id
531  */
532 const char *fdtdec_get_compatible(enum fdt_compat_id id);
533 
534 /* Look up a phandle and follow it to its node. Then return the offset
535  * of that node.
536  *
537  * @param blob		FDT blob
538  * @param node		node to examine
539  * @param prop_name	name of property to find
540  * @return node offset if found, -ve error code on error
541  */
542 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
543 
544 /**
545  * Look up a property in a node and return its contents in an integer
546  * array of given length. The property must have at least enough data for
547  * the array (4*count bytes). It may have more, but this will be ignored.
548  *
549  * @param blob		FDT blob
550  * @param node		node to examine
551  * @param prop_name	name of property to find
552  * @param array		array to fill with data
553  * @param count		number of array elements
554  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
555  *		or -FDT_ERR_BADLAYOUT if not enough data
556  */
557 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
558 		u32 *array, int count);
559 
560 /**
561  * Look up a property in a node and return its contents in an integer
562  * array of given length. The property must exist but may have less data that
563  * expected (4*count bytes). It may have more, but this will be ignored.
564  *
565  * @param blob		FDT blob
566  * @param node		node to examine
567  * @param prop_name	name of property to find
568  * @param array		array to fill with data
569  * @param count		number of array elements
570  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
571  *		property is not found
572  */
573 int fdtdec_get_int_array_count(const void *blob, int node,
574 			       const char *prop_name, u32 *array, int count);
575 
576 /**
577  * Look up a property in a node and return a pointer to its contents as a
578  * unsigned int array of given length. The property must have at least enough
579  * data for the array ('count' cells). It may have more, but this will be
580  * ignored. The data is not copied.
581  *
582  * Note that you must access elements of the array with fdt32_to_cpu(),
583  * since the elements will be big endian even on a little endian machine.
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 array if found, or NULL if the property is not
590  *		found or there is not enough data
591  */
592 const u32 *fdtdec_locate_array(const void *blob, int node,
593 			       const char *prop_name, int count);
594 
595 /**
596  * Look up a boolean property in a node and return it.
597  *
598  * A boolean properly is true if present in the device tree and false if not
599  * present, regardless of its value.
600  *
601  * @param blob	FDT blob
602  * @param node	node to examine
603  * @param prop_name	name of property to find
604  * @return 1 if the properly is present; 0 if it isn't present
605  */
606 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
607 
608 /**
609  * Look in the FDT for a config item with the given name and return its value
610  * as a 32-bit integer. The property must have at least 4 bytes of data. The
611  * value of the first cell is returned.
612  *
613  * @param blob		FDT blob to use
614  * @param prop_name	Node property name
615  * @param default_val	default value to return if the property is not found
616  * @return integer value, if found, or default_val if not
617  */
618 int fdtdec_get_config_int(const void *blob, const char *prop_name,
619 		int default_val);
620 
621 /**
622  * Look in the FDT for a config item with the given name
623  * and return whether it exists.
624  *
625  * @param blob		FDT blob
626  * @param prop_name	property name to look up
627  * @return 1, if it exists, or 0 if not
628  */
629 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
630 
631 /**
632  * Look in the FDT for a config item with the given name and return its value
633  * as a string.
634  *
635  * @param blob          FDT blob
636  * @param prop_name     property name to look up
637  * @returns property string, NULL on error.
638  */
639 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
640 
641 /*
642  * Look up a property in a node and return its contents in a byte
643  * array of given length. The property must have at least enough data for
644  * the array (count bytes). It may have more, but this will be ignored.
645  *
646  * @param blob		FDT blob
647  * @param node		node to examine
648  * @param prop_name	name of property to find
649  * @param array		array to fill with data
650  * @param count		number of array elements
651  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
652  *		or -FDT_ERR_BADLAYOUT if not enough data
653  */
654 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
655 		u8 *array, int count);
656 
657 /**
658  * Look up a property in a node and return a pointer to its contents as a
659  * byte array of given length. The property must have at least enough data
660  * for the array (count bytes). It may have more, but this will be ignored.
661  * The data is not copied.
662  *
663  * @param blob		FDT blob
664  * @param node		node to examine
665  * @param prop_name	name of property to find
666  * @param count		number of array elements
667  * @return pointer to byte array if found, or NULL if the property is not
668  *		found or there is not enough data
669  */
670 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
671 			     const char *prop_name, int count);
672 
673 /**
674  * Look up a property in a node which contains a memory region address and
675  * size. Then return a pointer to this address.
676  *
677  * The property must hold one address with a length. This is only tested on
678  * 32-bit machines.
679  *
680  * @param blob		FDT blob
681  * @param node		node to examine
682  * @param prop_name	name of property to find
683  * @param basep		Returns base address of region
684  * @param size		Returns size of region
685  * @return 0 if ok, -1 on error (property not found)
686  */
687 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
688 			 fdt_addr_t *basep, fdt_size_t *sizep);
689 
690 enum fmap_compress_t {
691 	FMAP_COMPRESS_NONE,
692 	FMAP_COMPRESS_LZO,
693 };
694 
695 enum fmap_hash_t {
696 	FMAP_HASH_NONE,
697 	FMAP_HASH_SHA1,
698 	FMAP_HASH_SHA256,
699 };
700 
701 /* A flash map entry, containing an offset and length */
702 struct fmap_entry {
703 	uint32_t offset;
704 	uint32_t length;
705 	uint32_t used;			/* Number of bytes used in region */
706 	enum fmap_compress_t compress_algo;	/* Compression type */
707 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
708 	const uint8_t *hash;			/* Hash value */
709 	int hash_size;				/* Hash size */
710 };
711 
712 /**
713  * Read a flash entry from the fdt
714  *
715  * @param blob		FDT blob
716  * @param node		Offset of node to read
717  * @param name		Name of node being read
718  * @param entry		Place to put offset and size of this node
719  * @return 0 if ok, -ve on error
720  */
721 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
722 			   struct fmap_entry *entry);
723 
724 /**
725  * Obtain an indexed resource from a device property.
726  *
727  * @param fdt		FDT blob
728  * @param node		node to examine
729  * @param property	name of the property to parse
730  * @param index		index of the resource to retrieve
731  * @param res		returns the resource
732  * @return 0 if ok, negative on error
733  */
734 int fdt_get_resource(const void *fdt, int node, const char *property,
735 		     unsigned int index, struct fdt_resource *res);
736 
737 /**
738  * Obtain a named resource from a device property.
739  *
740  * Look up the index of the name in a list of strings and return the resource
741  * at that index.
742  *
743  * @param fdt		FDT blob
744  * @param node		node to examine
745  * @param property	name of the property to parse
746  * @param prop_names	name of the property containing the list of names
747  * @param name		the name of the entry to look up
748  * @param res		returns the resource
749  */
750 int fdt_get_named_resource(const void *fdt, int node, const char *property,
751 			   const char *prop_names, const char *name,
752 			   struct fdt_resource *res);
753 
754 /**
755  * Decode a named region within a memory bank of a given type.
756  *
757  * This function handles selection of a memory region. The region is
758  * specified as an offset/size within a particular type of memory.
759  *
760  * The properties used are:
761  *
762  *	<mem_type>-memory<suffix> for the name of the memory bank
763  *	<mem_type>-offset<suffix> for the offset in that bank
764  *
765  * The property value must have an offset and a size. The function checks
766  * that the region is entirely within the memory bank.5
767  *
768  * @param blob		FDT blob
769  * @param node		Node containing the properties (-1 for /config)
770  * @param mem_type	Type of memory to use, which is a name, such as
771  *			"u-boot" or "kernel".
772  * @param suffix	String to append to the memory/offset
773  *			property names
774  * @param basep		Returns base of region
775  * @param sizep		Returns size of region
776  * @return 0 if OK, -ive on error
777  */
778 int fdtdec_decode_memory_region(const void *blob, int node,
779 				const char *mem_type, const char *suffix,
780 				fdt_addr_t *basep, fdt_size_t *sizep);
781 #endif
782