xref: /openbmc/u-boot/include/fdtdec.h (revision 29b103c7)
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 #ifdef CONFIG_SPL_BUILD
45 #define SPL_BUILD	1
46 #else
47 #define SPL_BUILD	0
48 #endif
49 
50 #ifdef CONFIG_OF_CONTROL
51 # if defined(CONFIG_SPL_BUILD) && defined(SPL_DISABLE_OF_CONTROL)
52 #  define OF_CONTROL 0
53 # else
54 #  define OF_CONTROL 1
55 # endif
56 #else
57 # define OF_CONTROL 0
58 #endif
59 
60 /*
61  * Information about a resource. start is the first address of the resource
62  * and end is the last address (inclusive). The length of the resource will
63  * be equal to: end - start + 1.
64  */
65 struct fdt_resource {
66 	fdt_addr_t start;
67 	fdt_addr_t end;
68 };
69 
70 enum fdt_pci_space {
71 	FDT_PCI_SPACE_CONFIG = 0,
72 	FDT_PCI_SPACE_IO = 0x01000000,
73 	FDT_PCI_SPACE_MEM32 = 0x02000000,
74 	FDT_PCI_SPACE_MEM64 = 0x03000000,
75 	FDT_PCI_SPACE_MEM32_PREF = 0x42000000,
76 	FDT_PCI_SPACE_MEM64_PREF = 0x43000000,
77 };
78 
79 #define FDT_PCI_ADDR_CELLS	3
80 #define FDT_PCI_SIZE_CELLS	2
81 #define FDT_PCI_REG_SIZE	\
82 	((FDT_PCI_ADDR_CELLS + FDT_PCI_SIZE_CELLS) * sizeof(u32))
83 
84 /*
85  * The Open Firmware spec defines PCI physical address as follows:
86  *
87  *          bits# 31 .... 24 23 .... 16 15 .... 08 07 .... 00
88  *
89  * phys.hi  cell:  npt000ss   bbbbbbbb   dddddfff   rrrrrrrr
90  * phys.mid cell:  hhhhhhhh   hhhhhhhh   hhhhhhhh   hhhhhhhh
91  * phys.lo  cell:  llllllll   llllllll   llllllll   llllllll
92  *
93  * where:
94  *
95  * n:        is 0 if the address is relocatable, 1 otherwise
96  * p:        is 1 if addressable region is prefetchable, 0 otherwise
97  * t:        is 1 if the address is aliased (for non-relocatable I/O) below 1MB
98  *           (for Memory), or below 64KB (for relocatable I/O)
99  * ss:       is the space code, denoting the address space
100  * bbbbbbbb: is the 8-bit Bus Number
101  * ddddd:    is the 5-bit Device Number
102  * fff:      is the 3-bit Function Number
103  * rrrrrrrr: is the 8-bit Register Number
104  * hhhhhhhh: is a 32-bit unsigned number
105  * llllllll: is a 32-bit unsigned number
106  */
107 struct fdt_pci_addr {
108 	u32	phys_hi;
109 	u32	phys_mid;
110 	u32	phys_lo;
111 };
112 
113 /**
114  * Compute the size of a resource.
115  *
116  * @param res	the resource to operate on
117  * @return the size of the resource
118  */
119 static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
120 {
121 	return res->end - res->start + 1;
122 }
123 
124 /**
125  * Compat types that we know about and for which we might have drivers.
126  * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
127  * within drivers.
128  */
129 enum fdt_compat_id {
130 	COMPAT_UNKNOWN,
131 	COMPAT_NVIDIA_TEGRA20_EMC,	/* Tegra20 memory controller */
132 	COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
133 	COMPAT_NVIDIA_TEGRA20_KBC,	/* Tegra20 Keyboard */
134 	COMPAT_NVIDIA_TEGRA20_NAND,	/* Tegra2 NAND controller */
135 	COMPAT_NVIDIA_TEGRA20_PWM,	/* Tegra 2 PWM controller */
136 	COMPAT_NVIDIA_TEGRA124_DC,	/* Tegra 124 Display controller */
137 	COMPAT_NVIDIA_TEGRA124_SOR,	/* Tegra 124 Serial Output Resource */
138 	COMPAT_NVIDIA_TEGRA124_PMC,	/* Tegra 124 power mgmt controller */
139 	COMPAT_NVIDIA_TEGRA20_DC,	/* Tegra 2 Display controller */
140 	COMPAT_NVIDIA_TEGRA124_SDMMC,	/* Tegra124 SDMMC controller */
141 	COMPAT_NVIDIA_TEGRA30_SDMMC,	/* Tegra30 SDMMC controller */
142 	COMPAT_NVIDIA_TEGRA20_SDMMC,	/* Tegra20 SDMMC controller */
143 	COMPAT_NVIDIA_TEGRA124_PCIE,	/* Tegra 124 PCIe controller */
144 	COMPAT_NVIDIA_TEGRA30_PCIE,	/* Tegra 30 PCIe controller */
145 	COMPAT_NVIDIA_TEGRA20_PCIE,	/* Tegra 20 PCIe controller */
146 	COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
147 					/* Tegra124 XUSB pad controller */
148 	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
149 	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
150 	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */
151 	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
152 	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */
153 	COMPAT_GOOGLE_CROS_EC_KEYB,	/* Google CROS_EC Keyboard */
154 	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */
155 	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
156 	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */
157 	COMPAT_SAMSUNG_EXYNOS_FIMD,	/* Exynos Display controller */
158 	COMPAT_SAMSUNG_EXYNOS_MIPI_DSI,	/* Exynos mipi dsi */
159 	COMPAT_SAMSUNG_EXYNOS5_DP,	/* Exynos Display port controller */
160 	COMPAT_SAMSUNG_EXYNOS_DWMMC,	/* Exynos DWMMC controller */
161 	COMPAT_SAMSUNG_EXYNOS_MMC,	/* Exynos MMC controller */
162 	COMPAT_SAMSUNG_EXYNOS_SERIAL,	/* Exynos UART */
163 	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */
164 	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */
165 	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */
166 	COMPAT_INFINEON_SLB9635_TPM,	/* Infineon SLB9635 TPM */
167 	COMPAT_INFINEON_SLB9645_TPM,	/* Infineon SLB9645 TPM */
168 	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */
169 	COMPAT_SANDBOX_LCD_SDL,		/* Sandbox LCD emulation with SDL */
170 	COMPAT_TI_TPS65090,		/* Texas Instrument TPS65090 */
171 	COMPAT_NXP_PTN3460,		/* NXP PTN3460 DP/LVDS bridge */
172 	COMPAT_SAMSUNG_EXYNOS_SYSMMU,	/* Exynos sysmmu */
173 	COMPAT_PARADE_PS8625,		/* Parade PS8622 EDP->LVDS bridge */
174 	COMPAT_INTEL_MICROCODE,		/* Intel microcode update */
175 	COMPAT_MEMORY_SPD,		/* Memory SPD information */
176 	COMPAT_INTEL_PANTHERPOINT_AHCI,	/* Intel Pantherpoint AHCI */
177 	COMPAT_INTEL_MODEL_206AX,	/* Intel Model 206AX CPU */
178 	COMPAT_INTEL_GMA,		/* Intel Graphics Media Accelerator */
179 	COMPAT_AMS_AS3722,		/* AMS AS3722 PMIC */
180 	COMPAT_INTEL_ICH_SPI,		/* Intel ICH7/9 SPI controller */
181 	COMPAT_INTEL_QRK_MRC,		/* Intel Quark MRC */
182 	COMPAT_INTEL_X86_PINCTRL,	/* Intel ICH7/9 pin control */
183 	COMPAT_SOCIONEXT_XHCI,		/* Socionext UniPhier xHCI */
184 	COMPAT_INTEL_PCH,		/* Intel PCH */
185 	COMPAT_INTEL_IRQ_ROUTER,	/* Intel Interrupt Router */
186 
187 	COMPAT_COUNT,
188 };
189 
190 #define MAX_PHANDLE_ARGS 16
191 struct fdtdec_phandle_args {
192 	int node;
193 	int args_count;
194 	uint32_t args[MAX_PHANDLE_ARGS];
195 };
196 
197 /**
198  * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
199  *
200  * This function is useful to parse lists of phandles and their arguments.
201  *
202  * Example:
203  *
204  * phandle1: node1 {
205  *	#list-cells = <2>;
206  * }
207  *
208  * phandle2: node2 {
209  *	#list-cells = <1>;
210  * }
211  *
212  * node3 {
213  *	list = <&phandle1 1 2 &phandle2 3>;
214  * }
215  *
216  * To get a device_node of the `node2' node you may call this:
217  * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
218  *				  &args);
219  *
220  * (This function is a modified version of __of_parse_phandle_with_args() from
221  * Linux 3.18)
222  *
223  * @blob:	Pointer to device tree
224  * @src_node:	Offset of device tree node containing a list
225  * @list_name:	property name that contains a list
226  * @cells_name:	property name that specifies the phandles' arguments count,
227  *		or NULL to use @cells_count
228  * @cells_count: Cell count to use if @cells_name is NULL
229  * @index:	index of a phandle to parse out
230  * @out_args:	optional pointer to output arguments structure (will be filled)
231  * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
232  *	@list_name does not exist, a phandle was not found, @cells_name
233  *	could not be found, the arguments were truncated or there were too
234  *	many arguments.
235  *
236  */
237 int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
238 				   const char *list_name,
239 				   const char *cells_name,
240 				   int cell_count, int index,
241 				   struct fdtdec_phandle_args *out_args);
242 
243 /**
244  * Find the next numbered alias for a peripheral. This is used to enumerate
245  * all the peripherals of a certain type.
246  *
247  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
248  * this function will return a pointer to the node the alias points to, and
249  * then update *upto to 1. Next time you call this function, the next node
250  * will be returned.
251  *
252  * All nodes returned will match the compatible ID, as it is assumed that
253  * all peripherals use the same driver.
254  *
255  * @param blob		FDT blob to use
256  * @param name		Root name of alias to search for
257  * @param id		Compatible ID to look for
258  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
259  */
260 int fdtdec_next_alias(const void *blob, const char *name,
261 		enum fdt_compat_id id, int *upto);
262 
263 /**
264  * Find the compatible ID for a given node.
265  *
266  * Generally each node has at least one compatible string attached to it.
267  * This function looks through our list of known compatible strings and
268  * returns the corresponding ID which matches the compatible string.
269  *
270  * @param blob		FDT blob to use
271  * @param node		Node containing compatible string to find
272  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
273  */
274 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
275 
276 /**
277  * Find the next compatible node for a peripheral.
278  *
279  * Do the first call with node = 0. This function will return a pointer to
280  * the next compatible node. Next time you call this function, pass the
281  * value returned, 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  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
287  */
288 int fdtdec_next_compatible(const void *blob, int node,
289 		enum fdt_compat_id id);
290 
291 /**
292  * Find the next compatible subnode for a peripheral.
293  *
294  * Do the first call with node set to the parent and depth = 0. This
295  * function will return the offset of the next compatible node. Next time
296  * you call this function, pass the node value returned last time, with
297  * depth unchanged, and the next node will be provided.
298  *
299  * @param blob		FDT blob to use
300  * @param node		Start node for search
301  * @param id		Compatible ID to look for (enum fdt_compat_id)
302  * @param depthp	Current depth (set to 0 before first call)
303  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
304  */
305 int fdtdec_next_compatible_subnode(const void *blob, int node,
306 		enum fdt_compat_id id, int *depthp);
307 
308 /**
309  * Look up an address property in a node and return it as an address.
310  * The property must hold either one address with no trailing data or
311  * one address with a length. This is only tested on 32-bit machines.
312  *
313  * @param blob	FDT blob
314  * @param node	node to examine
315  * @param prop_name	name of property to find
316  * @return address, if found, or FDT_ADDR_T_NONE if not
317  */
318 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
319 		const char *prop_name);
320 
321 /**
322  * Look up an address property in a node and return it as an address.
323  * The property must hold one address with a length. This is only tested
324  * on 32-bit machines.
325  *
326  * @param blob	FDT blob
327  * @param node	node to examine
328  * @param prop_name	name of property to find
329  * @return address, if found, or FDT_ADDR_T_NONE if not
330  */
331 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
332 		const char *prop_name, fdt_size_t *sizep);
333 
334 /**
335  * Look at an address property in a node and return the pci address which
336  * corresponds to the given type in the form of fdt_pci_addr.
337  * The property must hold one fdt_pci_addr with a lengh.
338  *
339  * @param blob		FDT blob
340  * @param node		node to examine
341  * @param type		pci address type (FDT_PCI_SPACE_xxx)
342  * @param prop_name	name of property to find
343  * @param addr		returns pci address in the form of fdt_pci_addr
344  * @return 0 if ok, -ENOENT if the property did not exist, -EINVAL if the
345  *		format of the property was invalid, -ENXIO if the requested
346  *		address type was not found
347  */
348 int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
349 		const char *prop_name, struct fdt_pci_addr *addr);
350 
351 /**
352  * Look at the compatible property of a device node that represents a PCI
353  * device and extract pci vendor id and device id from it.
354  *
355  * @param blob		FDT blob
356  * @param node		node to examine
357  * @param vendor	vendor id of the pci device
358  * @param device	device id of the pci device
359  * @return 0 if ok, negative on error
360  */
361 int fdtdec_get_pci_vendev(const void *blob, int node,
362 		u16 *vendor, u16 *device);
363 
364 /**
365  * Look at the pci address of a device node that represents a PCI device
366  * and parse the bus, device and function number from it. For some cases
367  * like the bus number encoded in reg property is not correct after pci
368  * enumeration, this function looks through the node's compatible strings
369  * to get these numbers extracted instead.
370  *
371  * @param blob		FDT blob
372  * @param node		node to examine
373  * @param addr		pci address in the form of fdt_pci_addr
374  * @param bdf		returns bus, device, function triplet
375  * @return 0 if ok, negative on error
376  */
377 int fdtdec_get_pci_bdf(const void *blob, int node,
378 		struct fdt_pci_addr *addr, pci_dev_t *bdf);
379 
380 /**
381  * Look at the pci address of a device node that represents a PCI device
382  * and return base address of the pci device's registers.
383  *
384  * @param blob		FDT blob
385  * @param node		node to examine
386  * @param addr		pci address in the form of fdt_pci_addr
387  * @param bar		returns base address of the pci device's registers
388  * @return 0 if ok, negative on error
389  */
390 int fdtdec_get_pci_bar32(const void *blob, int node,
391 		struct fdt_pci_addr *addr, u32 *bar);
392 
393 /**
394  * Look up a 32-bit integer property in a node and return it. The property
395  * must have at least 4 bytes of data. The value of the first cell is
396  * returned.
397  *
398  * @param blob	FDT blob
399  * @param node	node to examine
400  * @param prop_name	name of property to find
401  * @param default_val	default value to return if the property is not found
402  * @return integer value, if found, or default_val if not
403  */
404 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
405 		s32 default_val);
406 
407 /**
408  * Get a variable-sized number from a property
409  *
410  * This reads a number from one or more cells.
411  *
412  * @param ptr	Pointer to property
413  * @param cells	Number of cells containing the number
414  * @return the value in the cells
415  */
416 u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells);
417 
418 /**
419  * Look up a 64-bit integer property in a node and return it. The property
420  * must have at least 8 bytes of data (2 cells). The first two cells are
421  * concatenated to form a 8 bytes value, where the first cell is top half and
422  * the second cell is bottom half.
423  *
424  * @param blob	FDT blob
425  * @param node	node to examine
426  * @param prop_name	name of property to find
427  * @param default_val	default value to return if the property is not found
428  * @return integer value, if found, or default_val if not
429  */
430 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
431 		uint64_t default_val);
432 
433 /**
434  * Checks whether a node is enabled.
435  * This looks for a 'status' property. If this exists, then returns 1 if
436  * the status is 'ok' and 0 otherwise. If there is no status property,
437  * it returns 1 on the assumption that anything mentioned should be enabled
438  * by default.
439  *
440  * @param blob	FDT blob
441  * @param node	node to examine
442  * @return integer value 0 (not enabled) or 1 (enabled)
443  */
444 int fdtdec_get_is_enabled(const void *blob, int node);
445 
446 /**
447  * Make sure we have a valid fdt available to control U-Boot.
448  *
449  * If not, a message is printed to the console if the console is ready.
450  *
451  * @return 0 if all ok, -1 if not
452  */
453 int fdtdec_prepare_fdt(void);
454 
455 /**
456  * Checks that we have a valid fdt available to control U-Boot.
457 
458  * However, if not then for the moment nothing is done, since this function
459  * is called too early to panic().
460  *
461  * @returns 0
462  */
463 int fdtdec_check_fdt(void);
464 
465 /**
466  * Find the nodes for a peripheral and return a list of them in the correct
467  * order. This is used to enumerate all the peripherals of a certain type.
468  *
469  * To use this, optionally set up a /aliases node with alias properties for
470  * a peripheral. For example, for usb you could have:
471  *
472  * aliases {
473  *		usb0 = "/ehci@c5008000";
474  *		usb1 = "/ehci@c5000000";
475  * };
476  *
477  * Pass "usb" as the name to this function and will return a list of two
478  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
479  *
480  * All nodes returned will match the compatible ID, as it is assumed that
481  * all peripherals use the same driver.
482  *
483  * If no alias node is found, then the node list will be returned in the
484  * order found in the fdt. If the aliases mention a node which doesn't
485  * exist, then this will be ignored. If nodes are found with no aliases,
486  * they will be added in any order.
487  *
488  * If there is a gap in the aliases, then this function return a 0 node at
489  * that position. The return value will also count these gaps.
490  *
491  * This function checks node properties and will not return nodes which are
492  * marked disabled (status = "disabled").
493  *
494  * @param blob		FDT blob to use
495  * @param name		Root name of alias to search for
496  * @param id		Compatible ID to look for
497  * @param node_list	Place to put list of found nodes
498  * @param maxcount	Maximum number of nodes to find
499  * @return number of nodes found on success, FTD_ERR_... on error
500  */
501 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
502 			enum fdt_compat_id id, int *node_list, int maxcount);
503 
504 /*
505  * This function is similar to fdtdec_find_aliases_for_id() except that it
506  * adds to the node_list that is passed in. Any 0 elements are considered
507  * available for allocation - others are considered already used and are
508  * skipped.
509  *
510  * You can use this by calling fdtdec_find_aliases_for_id() with an
511  * uninitialised array, then setting the elements that are returned to -1,
512  * say, then calling this function, perhaps with a different compat id.
513  * Any elements you get back that are >0 are new nodes added by the call
514  * to this function.
515  *
516  * Note that if you have some nodes with aliases and some without, you are
517  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
518  * one compat_id may fill in positions for which you have aliases defined
519  * for another compat_id. When you later call *this* function with the second
520  * compat_id, the alias positions may already be used. A debug warning may
521  * be generated in this case, but it is safest to define aliases for all
522  * nodes when you care about the ordering.
523  */
524 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
525 			enum fdt_compat_id id, int *node_list, int maxcount);
526 
527 /**
528  * Get the alias sequence number of a node
529  *
530  * This works out whether a node is pointed to by an alias, and if so, the
531  * sequence number of that alias. Aliases are of the form <base><num> where
532  * <num> is the sequence number. For example spi2 would be sequence number
533  * 2.
534  *
535  * @param blob		Device tree blob (if NULL, then error is returned)
536  * @param base		Base name for alias (before the underscore)
537  * @param node		Node to look up
538  * @param seqp		This is set to the sequence number if one is found,
539  *			but otherwise the value is left alone
540  * @return 0 if a sequence was found, -ve if not
541  */
542 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
543 			 int *seqp);
544 
545 /**
546  * Get the offset of the given chosen node
547  *
548  * This looks up a property in /chosen containing the path to another node,
549  * then finds the offset of that node.
550  *
551  * @param blob		Device tree blob (if NULL, then error is returned)
552  * @param name		Property name, e.g. "stdout-path"
553  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
554  */
555 int fdtdec_get_chosen_node(const void *blob, const char *name);
556 
557 /*
558  * Get the name for a compatible ID
559  *
560  * @param id		Compatible ID to look for
561  * @return compatible string for that id
562  */
563 const char *fdtdec_get_compatible(enum fdt_compat_id id);
564 
565 /* Look up a phandle and follow it to its node. Then return the offset
566  * of that node.
567  *
568  * @param blob		FDT blob
569  * @param node		node to examine
570  * @param prop_name	name of property to find
571  * @return node offset if found, -ve error code on error
572  */
573 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
574 
575 /**
576  * Look up a property in a node and return its contents in an integer
577  * array of given length. The property must have at least enough data for
578  * the array (4*count bytes). It may have more, but this will be ignored.
579  *
580  * @param blob		FDT blob
581  * @param node		node to examine
582  * @param prop_name	name of property to find
583  * @param array		array to fill with data
584  * @param count		number of array elements
585  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
586  *		or -FDT_ERR_BADLAYOUT if not enough data
587  */
588 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
589 		u32 *array, int count);
590 
591 /**
592  * Look up a property in a node and return its contents in an integer
593  * array of given length. The property must exist but may have less data that
594  * expected (4*count bytes). It may have more, but this will be ignored.
595  *
596  * @param blob		FDT blob
597  * @param node		node to examine
598  * @param prop_name	name of property to find
599  * @param array		array to fill with data
600  * @param count		number of array elements
601  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
602  *		property is not found
603  */
604 int fdtdec_get_int_array_count(const void *blob, int node,
605 			       const char *prop_name, u32 *array, int count);
606 
607 /**
608  * Look up a property in a node and return a pointer to its contents as a
609  * unsigned int array of given length. The property must have at least enough
610  * data for the array ('count' cells). It may have more, but this will be
611  * ignored. The data is not copied.
612  *
613  * Note that you must access elements of the array with fdt32_to_cpu(),
614  * since the elements will be big endian even on a little endian machine.
615  *
616  * @param blob		FDT blob
617  * @param node		node to examine
618  * @param prop_name	name of property to find
619  * @param count		number of array elements
620  * @return pointer to array if found, or NULL if the property is not
621  *		found or there is not enough data
622  */
623 const u32 *fdtdec_locate_array(const void *blob, int node,
624 			       const char *prop_name, int count);
625 
626 /**
627  * Look up a boolean property in a node and return it.
628  *
629  * A boolean properly is true if present in the device tree and false if not
630  * present, regardless of its value.
631  *
632  * @param blob	FDT blob
633  * @param node	node to examine
634  * @param prop_name	name of property to find
635  * @return 1 if the properly is present; 0 if it isn't present
636  */
637 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
638 
639 /**
640  * Look in the FDT for a config item with the given name and return its value
641  * as a 32-bit integer. The property must have at least 4 bytes of data. The
642  * value of the first cell is returned.
643  *
644  * @param blob		FDT blob to use
645  * @param prop_name	Node property name
646  * @param default_val	default value to return if the property is not found
647  * @return integer value, if found, or default_val if not
648  */
649 int fdtdec_get_config_int(const void *blob, const char *prop_name,
650 		int default_val);
651 
652 /**
653  * Look in the FDT for a config item with the given name
654  * and return whether it exists.
655  *
656  * @param blob		FDT blob
657  * @param prop_name	property name to look up
658  * @return 1, if it exists, or 0 if not
659  */
660 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
661 
662 /**
663  * Look in the FDT for a config item with the given name and return its value
664  * as a string.
665  *
666  * @param blob          FDT blob
667  * @param prop_name     property name to look up
668  * @returns property string, NULL on error.
669  */
670 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
671 
672 /*
673  * Look up a property in a node and return its contents in a byte
674  * array of given length. The property must have at least enough data for
675  * the array (count bytes). It may have more, but this will be ignored.
676  *
677  * @param blob		FDT blob
678  * @param node		node to examine
679  * @param prop_name	name of property to find
680  * @param array		array to fill with data
681  * @param count		number of array elements
682  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
683  *		or -FDT_ERR_BADLAYOUT if not enough data
684  */
685 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
686 		u8 *array, int count);
687 
688 /**
689  * Look up a property in a node and return a pointer to its contents as a
690  * byte array of given length. The property must have at least enough data
691  * for the array (count bytes). It may have more, but this will be ignored.
692  * The data is not copied.
693  *
694  * @param blob		FDT blob
695  * @param node		node to examine
696  * @param prop_name	name of property to find
697  * @param count		number of array elements
698  * @return pointer to byte array if found, or NULL if the property is not
699  *		found or there is not enough data
700  */
701 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
702 			     const char *prop_name, int count);
703 
704 /**
705  * Look up a property in a node which contains a memory region address and
706  * size. Then return a pointer to this address.
707  *
708  * The property must hold one address with a length. This is only tested on
709  * 32-bit machines.
710  *
711  * @param blob		FDT blob
712  * @param node		node to examine
713  * @param prop_name	name of property to find
714  * @param basep		Returns base address of region
715  * @param size		Returns size of region
716  * @return 0 if ok, -1 on error (property not found)
717  */
718 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
719 			 fdt_addr_t *basep, fdt_size_t *sizep);
720 
721 enum fmap_compress_t {
722 	FMAP_COMPRESS_NONE,
723 	FMAP_COMPRESS_LZO,
724 };
725 
726 enum fmap_hash_t {
727 	FMAP_HASH_NONE,
728 	FMAP_HASH_SHA1,
729 	FMAP_HASH_SHA256,
730 };
731 
732 /* A flash map entry, containing an offset and length */
733 struct fmap_entry {
734 	uint32_t offset;
735 	uint32_t length;
736 	uint32_t used;			/* Number of bytes used in region */
737 	enum fmap_compress_t compress_algo;	/* Compression type */
738 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
739 	const uint8_t *hash;			/* Hash value */
740 	int hash_size;				/* Hash size */
741 };
742 
743 /**
744  * Read a flash entry from the fdt
745  *
746  * @param blob		FDT blob
747  * @param node		Offset of node to read
748  * @param name		Name of node being read
749  * @param entry		Place to put offset and size of this node
750  * @return 0 if ok, -ve on error
751  */
752 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
753 			   struct fmap_entry *entry);
754 
755 /**
756  * Obtain an indexed resource from a device property.
757  *
758  * @param fdt		FDT blob
759  * @param node		node to examine
760  * @param property	name of the property to parse
761  * @param index		index of the resource to retrieve
762  * @param res		returns the resource
763  * @return 0 if ok, negative on error
764  */
765 int fdt_get_resource(const void *fdt, int node, const char *property,
766 		     unsigned int index, struct fdt_resource *res);
767 
768 /**
769  * Obtain a named resource from a device property.
770  *
771  * Look up the index of the name in a list of strings and return the resource
772  * at that index.
773  *
774  * @param fdt		FDT blob
775  * @param node		node to examine
776  * @param property	name of the property to parse
777  * @param prop_names	name of the property containing the list of names
778  * @param name		the name of the entry to look up
779  * @param res		returns the resource
780  */
781 int fdt_get_named_resource(const void *fdt, int node, const char *property,
782 			   const char *prop_names, const char *name,
783 			   struct fdt_resource *res);
784 
785 /**
786  * Decode a named region within a memory bank of a given type.
787  *
788  * This function handles selection of a memory region. The region is
789  * specified as an offset/size within a particular type of memory.
790  *
791  * The properties used are:
792  *
793  *	<mem_type>-memory<suffix> for the name of the memory bank
794  *	<mem_type>-offset<suffix> for the offset in that bank
795  *
796  * The property value must have an offset and a size. The function checks
797  * that the region is entirely within the memory bank.5
798  *
799  * @param blob		FDT blob
800  * @param node		Node containing the properties (-1 for /config)
801  * @param mem_type	Type of memory to use, which is a name, such as
802  *			"u-boot" or "kernel".
803  * @param suffix	String to append to the memory/offset
804  *			property names
805  * @param basep		Returns base of region
806  * @param sizep		Returns size of region
807  * @return 0 if OK, -ive on error
808  */
809 int fdtdec_decode_memory_region(const void *blob, int node,
810 				const char *mem_type, const char *suffix,
811 				fdt_addr_t *basep, fdt_size_t *sizep);
812 
813 /* Display timings from linux include/video/display_timing.h */
814 enum display_flags {
815 	DISPLAY_FLAGS_HSYNC_LOW		= 1 << 0,
816 	DISPLAY_FLAGS_HSYNC_HIGH	= 1 << 1,
817 	DISPLAY_FLAGS_VSYNC_LOW		= 1 << 2,
818 	DISPLAY_FLAGS_VSYNC_HIGH	= 1 << 3,
819 
820 	/* data enable flag */
821 	DISPLAY_FLAGS_DE_LOW		= 1 << 4,
822 	DISPLAY_FLAGS_DE_HIGH		= 1 << 5,
823 	/* drive data on pos. edge */
824 	DISPLAY_FLAGS_PIXDATA_POSEDGE	= 1 << 6,
825 	/* drive data on neg. edge */
826 	DISPLAY_FLAGS_PIXDATA_NEGEDGE	= 1 << 7,
827 	DISPLAY_FLAGS_INTERLACED	= 1 << 8,
828 	DISPLAY_FLAGS_DOUBLESCAN	= 1 << 9,
829 	DISPLAY_FLAGS_DOUBLECLK		= 1 << 10,
830 };
831 
832 /*
833  * A single signal can be specified via a range of minimal and maximal values
834  * with a typical value, that lies somewhere inbetween.
835  */
836 struct timing_entry {
837 	u32 min;
838 	u32 typ;
839 	u32 max;
840 };
841 
842 /*
843  * Single "mode" entry. This describes one set of signal timings a display can
844  * have in one setting. This struct can later be converted to struct videomode
845  * (see include/video/videomode.h). As each timing_entry can be defined as a
846  * range, one struct display_timing may become multiple struct videomodes.
847  *
848  * Example: hsync active high, vsync active low
849  *
850  *				    Active Video
851  * Video  ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
852  *	  |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
853  *	  |	     |	 porch  |		     |	 porch	 |
854  *
855  * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯
856  *
857  * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________
858  */
859 struct display_timing {
860 	struct timing_entry pixelclock;
861 
862 	struct timing_entry hactive;		/* hor. active video */
863 	struct timing_entry hfront_porch;	/* hor. front porch */
864 	struct timing_entry hback_porch;	/* hor. back porch */
865 	struct timing_entry hsync_len;		/* hor. sync len */
866 
867 	struct timing_entry vactive;		/* ver. active video */
868 	struct timing_entry vfront_porch;	/* ver. front porch */
869 	struct timing_entry vback_porch;	/* ver. back porch */
870 	struct timing_entry vsync_len;		/* ver. sync len */
871 
872 	enum display_flags flags;		/* display flags */
873 };
874 
875 /**
876  * fdtdec_decode_display_timing() - decode display timings
877  *
878  * Decode display timings from the supplied 'display-timings' node.
879  * See doc/device-tree-bindings/video/display-timing.txt for binding
880  * information.
881  *
882  * @param blob		FDT blob
883  * @param node		'display-timing' node containing the timing subnodes
884  * @param index		Index number to read (0=first timing subnode)
885  * @param config	Place to put timings
886  * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
887  */
888 int fdtdec_decode_display_timing(const void *blob, int node, int index,
889 				 struct display_timing *config);
890 /**
891  * Set up the device tree ready for use
892  */
893 int fdtdec_setup(void);
894 
895 #endif
896