xref: /openbmc/u-boot/include/fdtdec.h (revision 3a1a18ff)
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 
171 	COMPAT_COUNT,
172 };
173 
174 #define MAX_PHANDLE_ARGS 16
175 struct fdtdec_phandle_args {
176 	int node;
177 	int args_count;
178 	uint32_t args[MAX_PHANDLE_ARGS];
179 };
180 
181 /**
182  * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
183  *
184  * This function is useful to parse lists of phandles and their arguments.
185  *
186  * Example:
187  *
188  * phandle1: node1 {
189  *	#list-cells = <2>;
190  * }
191  *
192  * phandle2: node2 {
193  *	#list-cells = <1>;
194  * }
195  *
196  * node3 {
197  *	list = <&phandle1 1 2 &phandle2 3>;
198  * }
199  *
200  * To get a device_node of the `node2' node you may call this:
201  * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
202  *				  &args);
203  *
204  * (This function is a modified version of __of_parse_phandle_with_args() from
205  * Linux 3.18)
206  *
207  * @blob:	Pointer to device tree
208  * @src_node:	Offset of device tree node containing a list
209  * @list_name:	property name that contains a list
210  * @cells_name:	property name that specifies the phandles' arguments count,
211  *		or NULL to use @cells_count
212  * @cells_count: Cell count to use if @cells_name is NULL
213  * @index:	index of a phandle to parse out
214  * @out_args:	optional pointer to output arguments structure (will be filled)
215  * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
216  *	@list_name does not exist, a phandle was not found, @cells_name
217  *	could not be found, the arguments were truncated or there were too
218  *	many arguments.
219  *
220  */
221 int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
222 				   const char *list_name,
223 				   const char *cells_name,
224 				   int cell_count, int index,
225 				   struct fdtdec_phandle_args *out_args);
226 
227 /**
228  * Find the next numbered alias for a peripheral. This is used to enumerate
229  * all the peripherals of a certain type.
230  *
231  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
232  * this function will return a pointer to the node the alias points to, and
233  * then update *upto to 1. Next time you call this function, the next node
234  * will be returned.
235  *
236  * All nodes returned will match the compatible ID, as it is assumed that
237  * all peripherals use the same driver.
238  *
239  * @param blob		FDT blob to use
240  * @param name		Root name of alias to search for
241  * @param id		Compatible ID to look for
242  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
243  */
244 int fdtdec_next_alias(const void *blob, const char *name,
245 		enum fdt_compat_id id, int *upto);
246 
247 /**
248  * Find the compatible ID for a given node.
249  *
250  * Generally each node has at least one compatible string attached to it.
251  * This function looks through our list of known compatible strings and
252  * returns the corresponding ID which matches the compatible string.
253  *
254  * @param blob		FDT blob to use
255  * @param node		Node containing compatible string to find
256  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
257  */
258 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
259 
260 /**
261  * Find the next compatible node for a peripheral.
262  *
263  * Do the first call with node = 0. This function will return a pointer to
264  * the next compatible node. Next time you call this function, pass the
265  * value returned, and the next node will be provided.
266  *
267  * @param blob		FDT blob to use
268  * @param node		Start node for search
269  * @param id		Compatible ID to look for (enum fdt_compat_id)
270  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
271  */
272 int fdtdec_next_compatible(const void *blob, int node,
273 		enum fdt_compat_id id);
274 
275 /**
276  * Find the next compatible subnode for a peripheral.
277  *
278  * Do the first call with node set to the parent and depth = 0. This
279  * function will return the offset of the next compatible node. Next time
280  * you call this function, pass the node value returned last time, with
281  * depth unchanged, and the next node will be provided.
282  *
283  * @param blob		FDT blob to use
284  * @param node		Start node for search
285  * @param id		Compatible ID to look for (enum fdt_compat_id)
286  * @param depthp	Current depth (set to 0 before first call)
287  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
288  */
289 int fdtdec_next_compatible_subnode(const void *blob, int node,
290 		enum fdt_compat_id id, int *depthp);
291 
292 /**
293  * Look up an address property in a node and return it as an address.
294  * The property must hold either one address with no trailing data or
295  * one address with a length. This is only tested on 32-bit machines.
296  *
297  * @param blob	FDT blob
298  * @param node	node to examine
299  * @param prop_name	name of property to find
300  * @return address, if found, or FDT_ADDR_T_NONE if not
301  */
302 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
303 		const char *prop_name);
304 
305 /**
306  * Look up an address property in a node and return it as an address.
307  * The property must hold one address with a length. This is only tested
308  * on 32-bit machines.
309  *
310  * @param blob	FDT blob
311  * @param node	node to examine
312  * @param prop_name	name of property to find
313  * @return address, if found, or FDT_ADDR_T_NONE if not
314  */
315 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
316 		const char *prop_name, fdt_size_t *sizep);
317 
318 /**
319  * Look at an address property in a node and return the pci address which
320  * corresponds to the given type in the form of fdt_pci_addr.
321  * The property must hold one fdt_pci_addr with a lengh.
322  *
323  * @param blob		FDT blob
324  * @param node		node to examine
325  * @param type		pci address type (FDT_PCI_SPACE_xxx)
326  * @param prop_name	name of property to find
327  * @param addr		returns pci address in the form of fdt_pci_addr
328  * @return 0 if ok, negative on error
329  */
330 int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
331 		const char *prop_name, struct fdt_pci_addr *addr);
332 
333 /**
334  * Look at the compatible property of a device node that represents a PCI
335  * device and extract pci vendor id and device id from it.
336  *
337  * @param blob		FDT blob
338  * @param node		node to examine
339  * @param vendor	vendor id of the pci device
340  * @param device	device id of the pci device
341  * @return 0 if ok, negative on error
342  */
343 int fdtdec_get_pci_vendev(const void *blob, int node,
344 		u16 *vendor, u16 *device);
345 
346 /**
347  * Look at the pci address of a device node that represents a PCI device
348  * and parse the bus, device and function number from it.
349  *
350  * @param blob		FDT blob
351  * @param node		node to examine
352  * @param addr		pci address in the form of fdt_pci_addr
353  * @param bdf		returns bus, device, function triplet
354  * @return 0 if ok, negative on error
355  */
356 int fdtdec_get_pci_bdf(const void *blob, int node,
357 		struct fdt_pci_addr *addr, pci_dev_t *bdf);
358 
359 /**
360  * Look at the pci address of a device node that represents a PCI device
361  * and return base address of the pci device's registers.
362  *
363  * @param blob		FDT blob
364  * @param node		node to examine
365  * @param addr		pci address in the form of fdt_pci_addr
366  * @param bar		returns base address of the pci device's registers
367  * @return 0 if ok, negative on error
368  */
369 int fdtdec_get_pci_bar32(const void *blob, int node,
370 		struct fdt_pci_addr *addr, u32 *bar);
371 
372 /**
373  * Look up a 32-bit integer property in a node and return it. The property
374  * must have at least 4 bytes of data. The value of the first cell is
375  * returned.
376  *
377  * @param blob	FDT blob
378  * @param node	node to examine
379  * @param prop_name	name of property to find
380  * @param default_val	default value to return if the property is not found
381  * @return integer value, if found, or default_val if not
382  */
383 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
384 		s32 default_val);
385 
386 /**
387  * Look up a 64-bit integer property in a node and return it. The property
388  * must have at least 8 bytes of data (2 cells). The first two cells are
389  * concatenated to form a 8 bytes value, where the first cell is top half and
390  * the second cell is bottom half.
391  *
392  * @param blob	FDT blob
393  * @param node	node to examine
394  * @param prop_name	name of property to find
395  * @param default_val	default value to return if the property is not found
396  * @return integer value, if found, or default_val if not
397  */
398 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
399 		uint64_t default_val);
400 
401 /**
402  * Checks whether a node is enabled.
403  * This looks for a 'status' property. If this exists, then returns 1 if
404  * the status is 'ok' and 0 otherwise. If there is no status property,
405  * it returns 1 on the assumption that anything mentioned should be enabled
406  * by default.
407  *
408  * @param blob	FDT blob
409  * @param node	node to examine
410  * @return integer value 0 (not enabled) or 1 (enabled)
411  */
412 int fdtdec_get_is_enabled(const void *blob, int node);
413 
414 /**
415  * Make sure we have a valid fdt available to control U-Boot.
416  *
417  * If not, a message is printed to the console if the console is ready.
418  *
419  * @return 0 if all ok, -1 if not
420  */
421 int fdtdec_prepare_fdt(void);
422 
423 /**
424  * Checks that we have a valid fdt available to control U-Boot.
425 
426  * However, if not then for the moment nothing is done, since this function
427  * is called too early to panic().
428  *
429  * @returns 0
430  */
431 int fdtdec_check_fdt(void);
432 
433 /**
434  * Find the nodes for a peripheral and return a list of them in the correct
435  * order. This is used to enumerate all the peripherals of a certain type.
436  *
437  * To use this, optionally set up a /aliases node with alias properties for
438  * a peripheral. For example, for usb you could have:
439  *
440  * aliases {
441  *		usb0 = "/ehci@c5008000";
442  *		usb1 = "/ehci@c5000000";
443  * };
444  *
445  * Pass "usb" as the name to this function and will return a list of two
446  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
447  *
448  * All nodes returned will match the compatible ID, as it is assumed that
449  * all peripherals use the same driver.
450  *
451  * If no alias node is found, then the node list will be returned in the
452  * order found in the fdt. If the aliases mention a node which doesn't
453  * exist, then this will be ignored. If nodes are found with no aliases,
454  * they will be added in any order.
455  *
456  * If there is a gap in the aliases, then this function return a 0 node at
457  * that position. The return value will also count these gaps.
458  *
459  * This function checks node properties and will not return nodes which are
460  * marked disabled (status = "disabled").
461  *
462  * @param blob		FDT blob to use
463  * @param name		Root name of alias to search for
464  * @param id		Compatible ID to look for
465  * @param node_list	Place to put list of found nodes
466  * @param maxcount	Maximum number of nodes to find
467  * @return number of nodes found on success, FTD_ERR_... on error
468  */
469 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
470 			enum fdt_compat_id id, int *node_list, int maxcount);
471 
472 /*
473  * This function is similar to fdtdec_find_aliases_for_id() except that it
474  * adds to the node_list that is passed in. Any 0 elements are considered
475  * available for allocation - others are considered already used and are
476  * skipped.
477  *
478  * You can use this by calling fdtdec_find_aliases_for_id() with an
479  * uninitialised array, then setting the elements that are returned to -1,
480  * say, then calling this function, perhaps with a different compat id.
481  * Any elements you get back that are >0 are new nodes added by the call
482  * to this function.
483  *
484  * Note that if you have some nodes with aliases and some without, you are
485  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
486  * one compat_id may fill in positions for which you have aliases defined
487  * for another compat_id. When you later call *this* function with the second
488  * compat_id, the alias positions may already be used. A debug warning may
489  * be generated in this case, but it is safest to define aliases for all
490  * nodes when you care about the ordering.
491  */
492 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
493 			enum fdt_compat_id id, int *node_list, int maxcount);
494 
495 /**
496  * Get the alias sequence number of a node
497  *
498  * This works out whether a node is pointed to by an alias, and if so, the
499  * sequence number of that alias. Aliases are of the form <base><num> where
500  * <num> is the sequence number. For example spi2 would be sequence number
501  * 2.
502  *
503  * @param blob		Device tree blob (if NULL, then error is returned)
504  * @param base		Base name for alias (before the underscore)
505  * @param node		Node to look up
506  * @param seqp		This is set to the sequence number if one is found,
507  *			but otherwise the value is left alone
508  * @return 0 if a sequence was found, -ve if not
509  */
510 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
511 			 int *seqp);
512 
513 /**
514  * Get the offset of the given chosen node
515  *
516  * This looks up a property in /chosen containing the path to another node,
517  * then finds the offset of that node.
518  *
519  * @param blob		Device tree blob (if NULL, then error is returned)
520  * @param name		Property name, e.g. "stdout-path"
521  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
522  */
523 int fdtdec_get_chosen_node(const void *blob, const char *name);
524 
525 /*
526  * Get the name for a compatible ID
527  *
528  * @param id		Compatible ID to look for
529  * @return compatible string for that id
530  */
531 const char *fdtdec_get_compatible(enum fdt_compat_id id);
532 
533 /* Look up a phandle and follow it to its node. Then return the offset
534  * of that node.
535  *
536  * @param blob		FDT blob
537  * @param node		node to examine
538  * @param prop_name	name of property to find
539  * @return node offset if found, -ve error code on error
540  */
541 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
542 
543 /**
544  * Look up a property in a node and return its contents in an integer
545  * array of given length. The property must have at least enough data for
546  * the array (4*count bytes). It may have more, but this will be ignored.
547  *
548  * @param blob		FDT blob
549  * @param node		node to examine
550  * @param prop_name	name of property to find
551  * @param array		array to fill with data
552  * @param count		number of array elements
553  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
554  *		or -FDT_ERR_BADLAYOUT if not enough data
555  */
556 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
557 		u32 *array, int count);
558 
559 /**
560  * Look up a property in a node and return its contents in an integer
561  * array of given length. The property must exist but may have less data that
562  * expected (4*count bytes). It may have more, but this will be ignored.
563  *
564  * @param blob		FDT blob
565  * @param node		node to examine
566  * @param prop_name	name of property to find
567  * @param array		array to fill with data
568  * @param count		number of array elements
569  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
570  *		property is not found
571  */
572 int fdtdec_get_int_array_count(const void *blob, int node,
573 			       const char *prop_name, u32 *array, int count);
574 
575 /**
576  * Look up a property in a node and return a pointer to its contents as a
577  * unsigned int array of given length. The property must have at least enough
578  * data for the array ('count' cells). It may have more, but this will be
579  * ignored. The data is not copied.
580  *
581  * Note that you must access elements of the array with fdt32_to_cpu(),
582  * since the elements will be big endian even on a little endian machine.
583  *
584  * @param blob		FDT blob
585  * @param node		node to examine
586  * @param prop_name	name of property to find
587  * @param count		number of array elements
588  * @return pointer to array if found, or NULL if the property is not
589  *		found or there is not enough data
590  */
591 const u32 *fdtdec_locate_array(const void *blob, int node,
592 			       const char *prop_name, int count);
593 
594 /**
595  * Look up a boolean property in a node and return it.
596  *
597  * A boolean properly is true if present in the device tree and false if not
598  * present, regardless of its value.
599  *
600  * @param blob	FDT blob
601  * @param node	node to examine
602  * @param prop_name	name of property to find
603  * @return 1 if the properly is present; 0 if it isn't present
604  */
605 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
606 
607 /**
608  * Look in the FDT for a config item with the given name and return its value
609  * as a 32-bit integer. The property must have at least 4 bytes of data. The
610  * value of the first cell is returned.
611  *
612  * @param blob		FDT blob to use
613  * @param prop_name	Node property name
614  * @param default_val	default value to return if the property is not found
615  * @return integer value, if found, or default_val if not
616  */
617 int fdtdec_get_config_int(const void *blob, const char *prop_name,
618 		int default_val);
619 
620 /**
621  * Look in the FDT for a config item with the given name
622  * and return whether it exists.
623  *
624  * @param blob		FDT blob
625  * @param prop_name	property name to look up
626  * @return 1, if it exists, or 0 if not
627  */
628 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
629 
630 /**
631  * Look in the FDT for a config item with the given name and return its value
632  * as a string.
633  *
634  * @param blob          FDT blob
635  * @param prop_name     property name to look up
636  * @returns property string, NULL on error.
637  */
638 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
639 
640 /*
641  * Look up a property in a node and return its contents in a byte
642  * array of given length. The property must have at least enough data for
643  * the array (count bytes). It may have more, but this will be ignored.
644  *
645  * @param blob		FDT blob
646  * @param node		node to examine
647  * @param prop_name	name of property to find
648  * @param array		array to fill with data
649  * @param count		number of array elements
650  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
651  *		or -FDT_ERR_BADLAYOUT if not enough data
652  */
653 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
654 		u8 *array, int count);
655 
656 /**
657  * Look up a property in a node and return a pointer to its contents as a
658  * byte array of given length. The property must have at least enough data
659  * for the array (count bytes). It may have more, but this will be ignored.
660  * The data is not copied.
661  *
662  * @param blob		FDT blob
663  * @param node		node to examine
664  * @param prop_name	name of property to find
665  * @param count		number of array elements
666  * @return pointer to byte array if found, or NULL if the property is not
667  *		found or there is not enough data
668  */
669 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
670 			     const char *prop_name, int count);
671 
672 /**
673  * Look up a property in a node which contains a memory region address and
674  * size. Then return a pointer to this address.
675  *
676  * The property must hold one address with a length. This is only tested on
677  * 32-bit machines.
678  *
679  * @param blob		FDT blob
680  * @param node		node to examine
681  * @param prop_name	name of property to find
682  * @param basep		Returns base address of region
683  * @param size		Returns size of region
684  * @return 0 if ok, -1 on error (property not found)
685  */
686 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
687 			 fdt_addr_t *basep, fdt_size_t *sizep);
688 
689 enum fmap_compress_t {
690 	FMAP_COMPRESS_NONE,
691 	FMAP_COMPRESS_LZO,
692 };
693 
694 enum fmap_hash_t {
695 	FMAP_HASH_NONE,
696 	FMAP_HASH_SHA1,
697 	FMAP_HASH_SHA256,
698 };
699 
700 /* A flash map entry, containing an offset and length */
701 struct fmap_entry {
702 	uint32_t offset;
703 	uint32_t length;
704 	uint32_t used;			/* Number of bytes used in region */
705 	enum fmap_compress_t compress_algo;	/* Compression type */
706 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
707 	const uint8_t *hash;			/* Hash value */
708 	int hash_size;				/* Hash size */
709 };
710 
711 /**
712  * Read a flash entry from the fdt
713  *
714  * @param blob		FDT blob
715  * @param node		Offset of node to read
716  * @param name		Name of node being read
717  * @param entry		Place to put offset and size of this node
718  * @return 0 if ok, -ve on error
719  */
720 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
721 			   struct fmap_entry *entry);
722 
723 /**
724  * Obtain an indexed resource from a device property.
725  *
726  * @param fdt		FDT blob
727  * @param node		node to examine
728  * @param property	name of the property to parse
729  * @param index		index of the resource to retrieve
730  * @param res		returns the resource
731  * @return 0 if ok, negative on error
732  */
733 int fdt_get_resource(const void *fdt, int node, const char *property,
734 		     unsigned int index, struct fdt_resource *res);
735 
736 /**
737  * Obtain a named resource from a device property.
738  *
739  * Look up the index of the name in a list of strings and return the resource
740  * at that index.
741  *
742  * @param fdt		FDT blob
743  * @param node		node to examine
744  * @param property	name of the property to parse
745  * @param prop_names	name of the property containing the list of names
746  * @param name		the name of the entry to look up
747  * @param res		returns the resource
748  */
749 int fdt_get_named_resource(const void *fdt, int node, const char *property,
750 			   const char *prop_names, const char *name,
751 			   struct fdt_resource *res);
752 
753 /**
754  * Decode a named region within a memory bank of a given type.
755  *
756  * This function handles selection of a memory region. The region is
757  * specified as an offset/size within a particular type of memory.
758  *
759  * The properties used are:
760  *
761  *	<mem_type>-memory<suffix> for the name of the memory bank
762  *	<mem_type>-offset<suffix> for the offset in that bank
763  *
764  * The property value must have an offset and a size. The function checks
765  * that the region is entirely within the memory bank.5
766  *
767  * @param blob		FDT blob
768  * @param node		Node containing the properties (-1 for /config)
769  * @param mem_type	Type of memory to use, which is a name, such as
770  *			"u-boot" or "kernel".
771  * @param suffix	String to append to the memory/offset
772  *			property names
773  * @param basep		Returns base of region
774  * @param sizep		Returns size of region
775  * @return 0 if OK, -ive on error
776  */
777 int fdtdec_decode_memory_region(const void *blob, int node,
778 				const char *mem_type, const char *suffix,
779 				fdt_addr_t *basep, fdt_size_t *sizep);
780 #endif
781