xref: /openbmc/u-boot/include/fdtdec.h (revision 7fd078cb)
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_TEGRA210_SDMMC,	/* Tegra210 SDMMC controller */
141 	COMPAT_NVIDIA_TEGRA124_SDMMC,	/* Tegra124 SDMMC controller */
142 	COMPAT_NVIDIA_TEGRA30_SDMMC,	/* Tegra30 SDMMC controller */
143 	COMPAT_NVIDIA_TEGRA20_SDMMC,	/* Tegra20 SDMMC controller */
144 	COMPAT_NVIDIA_TEGRA124_PCIE,	/* Tegra 124 PCIe controller */
145 	COMPAT_NVIDIA_TEGRA30_PCIE,	/* Tegra 30 PCIe controller */
146 	COMPAT_NVIDIA_TEGRA20_PCIE,	/* Tegra 20 PCIe controller */
147 	COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
148 					/* Tegra124 XUSB pad controller */
149 	COMPAT_NVIDIA_TEGRA210_XUSB_PADCTL,
150 					/* Tegra210 XUSB pad controller */
151 	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
152 	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
153 	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */
154 	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
155 	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */
156 	COMPAT_GOOGLE_CROS_EC_KEYB,	/* Google CROS_EC Keyboard */
157 	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */
158 	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
159 	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */
160 	COMPAT_SAMSUNG_EXYNOS_FIMD,	/* Exynos Display controller */
161 	COMPAT_SAMSUNG_EXYNOS_MIPI_DSI,	/* Exynos mipi dsi */
162 	COMPAT_SAMSUNG_EXYNOS5_DP,	/* Exynos Display port controller */
163 	COMPAT_SAMSUNG_EXYNOS_DWMMC,	/* Exynos DWMMC controller */
164 	COMPAT_SAMSUNG_EXYNOS_MMC,	/* Exynos MMC controller */
165 	COMPAT_SAMSUNG_EXYNOS_SERIAL,	/* Exynos UART */
166 	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */
167 	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */
168 	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */
169 	COMPAT_INFINEON_SLB9635_TPM,	/* Infineon SLB9635 TPM */
170 	COMPAT_INFINEON_SLB9645_TPM,	/* Infineon SLB9645 TPM */
171 	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */
172 	COMPAT_SANDBOX_LCD_SDL,		/* Sandbox LCD emulation with SDL */
173 	COMPAT_TI_TPS65090,		/* Texas Instrument TPS65090 */
174 	COMPAT_NXP_PTN3460,		/* NXP PTN3460 DP/LVDS bridge */
175 	COMPAT_SAMSUNG_EXYNOS_SYSMMU,	/* Exynos sysmmu */
176 	COMPAT_PARADE_PS8625,		/* Parade PS8622 EDP->LVDS bridge */
177 	COMPAT_INTEL_MICROCODE,		/* Intel microcode update */
178 	COMPAT_MEMORY_SPD,		/* Memory SPD information */
179 	COMPAT_INTEL_PANTHERPOINT_AHCI,	/* Intel Pantherpoint AHCI */
180 	COMPAT_INTEL_MODEL_206AX,	/* Intel Model 206AX CPU */
181 	COMPAT_INTEL_GMA,		/* Intel Graphics Media Accelerator */
182 	COMPAT_AMS_AS3722,		/* AMS AS3722 PMIC */
183 	COMPAT_INTEL_ICH_SPI,		/* Intel ICH7/9 SPI controller */
184 	COMPAT_INTEL_QRK_MRC,		/* Intel Quark MRC */
185 	COMPAT_INTEL_X86_PINCTRL,	/* Intel ICH7/9 pin control */
186 	COMPAT_SOCIONEXT_XHCI,		/* Socionext UniPhier xHCI */
187 	COMPAT_INTEL_PCH,		/* Intel PCH */
188 	COMPAT_INTEL_IRQ_ROUTER,	/* Intel Interrupt Router */
189 
190 	COMPAT_COUNT,
191 };
192 
193 #define MAX_PHANDLE_ARGS 16
194 struct fdtdec_phandle_args {
195 	int node;
196 	int args_count;
197 	uint32_t args[MAX_PHANDLE_ARGS];
198 };
199 
200 /**
201  * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
202  *
203  * This function is useful to parse lists of phandles and their arguments.
204  *
205  * Example:
206  *
207  * phandle1: node1 {
208  *	#list-cells = <2>;
209  * }
210  *
211  * phandle2: node2 {
212  *	#list-cells = <1>;
213  * }
214  *
215  * node3 {
216  *	list = <&phandle1 1 2 &phandle2 3>;
217  * }
218  *
219  * To get a device_node of the `node2' node you may call this:
220  * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
221  *				  &args);
222  *
223  * (This function is a modified version of __of_parse_phandle_with_args() from
224  * Linux 3.18)
225  *
226  * @blob:	Pointer to device tree
227  * @src_node:	Offset of device tree node containing a list
228  * @list_name:	property name that contains a list
229  * @cells_name:	property name that specifies the phandles' arguments count,
230  *		or NULL to use @cells_count
231  * @cells_count: Cell count to use if @cells_name is NULL
232  * @index:	index of a phandle to parse out
233  * @out_args:	optional pointer to output arguments structure (will be filled)
234  * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
235  *	@list_name does not exist, a phandle was not found, @cells_name
236  *	could not be found, the arguments were truncated or there were too
237  *	many arguments.
238  *
239  */
240 int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
241 				   const char *list_name,
242 				   const char *cells_name,
243 				   int cell_count, int index,
244 				   struct fdtdec_phandle_args *out_args);
245 
246 /**
247  * Find the next numbered alias for a peripheral. This is used to enumerate
248  * all the peripherals of a certain type.
249  *
250  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
251  * this function will return a pointer to the node the alias points to, and
252  * then update *upto to 1. Next time you call this function, the next node
253  * will be returned.
254  *
255  * All nodes returned will match the compatible ID, as it is assumed that
256  * all peripherals use the same driver.
257  *
258  * @param blob		FDT blob to use
259  * @param name		Root name of alias to search for
260  * @param id		Compatible ID to look for
261  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
262  */
263 int fdtdec_next_alias(const void *blob, const char *name,
264 		enum fdt_compat_id id, int *upto);
265 
266 /**
267  * Find the compatible ID for a given node.
268  *
269  * Generally each node has at least one compatible string attached to it.
270  * This function looks through our list of known compatible strings and
271  * returns the corresponding ID which matches the compatible string.
272  *
273  * @param blob		FDT blob to use
274  * @param node		Node containing compatible string to find
275  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
276  */
277 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
278 
279 /**
280  * Find the next compatible node for a peripheral.
281  *
282  * Do the first call with node = 0. This function will return a pointer to
283  * the next compatible node. Next time you call this function, pass the
284  * value returned, and the next node will be provided.
285  *
286  * @param blob		FDT blob to use
287  * @param node		Start node for search
288  * @param id		Compatible ID to look for (enum fdt_compat_id)
289  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
290  */
291 int fdtdec_next_compatible(const void *blob, int node,
292 		enum fdt_compat_id id);
293 
294 /**
295  * Find the next compatible subnode for a peripheral.
296  *
297  * Do the first call with node set to the parent and depth = 0. This
298  * function will return the offset of the next compatible node. Next time
299  * you call this function, pass the node value returned last time, with
300  * depth unchanged, and the next node will be provided.
301  *
302  * @param blob		FDT blob to use
303  * @param node		Start node for search
304  * @param id		Compatible ID to look for (enum fdt_compat_id)
305  * @param depthp	Current depth (set to 0 before first call)
306  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
307  */
308 int fdtdec_next_compatible_subnode(const void *blob, int node,
309 		enum fdt_compat_id id, int *depthp);
310 
311 /**
312  * Look up an address property in a node and return it as an address.
313  * The property must hold either one address with no trailing data or
314  * one address with a length. This is only tested on 32-bit machines.
315  *
316  * @param blob	FDT blob
317  * @param node	node to examine
318  * @param prop_name	name of property to find
319  * @return address, if found, or FDT_ADDR_T_NONE if not
320  */
321 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
322 		const char *prop_name);
323 
324 /**
325  * Look up an address property in a node and return it as an address.
326  * The property must hold one address with a length. This is only tested
327  * on 32-bit machines.
328  *
329  * @param blob	FDT blob
330  * @param node	node to examine
331  * @param prop_name	name of property to find
332  * @return address, if found, or FDT_ADDR_T_NONE if not
333  */
334 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
335 		const char *prop_name, fdt_size_t *sizep);
336 
337 /**
338  * Look at an address property in a node and return the pci address which
339  * corresponds to the given type in the form of fdt_pci_addr.
340  * The property must hold one fdt_pci_addr with a lengh.
341  *
342  * @param blob		FDT blob
343  * @param node		node to examine
344  * @param type		pci address type (FDT_PCI_SPACE_xxx)
345  * @param prop_name	name of property to find
346  * @param addr		returns pci address in the form of fdt_pci_addr
347  * @return 0 if ok, -ENOENT if the property did not exist, -EINVAL if the
348  *		format of the property was invalid, -ENXIO if the requested
349  *		address type was not found
350  */
351 int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
352 		const char *prop_name, struct fdt_pci_addr *addr);
353 
354 /**
355  * Look at the compatible property of a device node that represents a PCI
356  * device and extract pci vendor id and device id from it.
357  *
358  * @param blob		FDT blob
359  * @param node		node to examine
360  * @param vendor	vendor id of the pci device
361  * @param device	device id of the pci device
362  * @return 0 if ok, negative on error
363  */
364 int fdtdec_get_pci_vendev(const void *blob, int node,
365 		u16 *vendor, u16 *device);
366 
367 /**
368  * Look at the pci address of a device node that represents a PCI device
369  * and parse the bus, device and function number from it. For some cases
370  * like the bus number encoded in reg property is not correct after pci
371  * enumeration, this function looks through the node's compatible strings
372  * to get these numbers extracted instead.
373  *
374  * @param blob		FDT blob
375  * @param node		node to examine
376  * @param addr		pci address in the form of fdt_pci_addr
377  * @param bdf		returns bus, device, function triplet
378  * @return 0 if ok, negative on error
379  */
380 int fdtdec_get_pci_bdf(const void *blob, int node,
381 		struct fdt_pci_addr *addr, pci_dev_t *bdf);
382 
383 /**
384  * Look at the pci address of a device node that represents a PCI device
385  * and return base address of the pci device's registers.
386  *
387  * @param blob		FDT blob
388  * @param node		node to examine
389  * @param addr		pci address in the form of fdt_pci_addr
390  * @param bar		returns base address of the pci device's registers
391  * @return 0 if ok, negative on error
392  */
393 int fdtdec_get_pci_bar32(const void *blob, int node,
394 		struct fdt_pci_addr *addr, u32 *bar);
395 
396 /**
397  * Look up a 32-bit integer property in a node and return it. The property
398  * must have at least 4 bytes of data. The value of the first cell is
399  * returned.
400  *
401  * @param blob	FDT blob
402  * @param node	node to examine
403  * @param prop_name	name of property to find
404  * @param default_val	default value to return if the property is not found
405  * @return integer value, if found, or default_val if not
406  */
407 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
408 		s32 default_val);
409 
410 /**
411  * Get a variable-sized number from a property
412  *
413  * This reads a number from one or more cells.
414  *
415  * @param ptr	Pointer to property
416  * @param cells	Number of cells containing the number
417  * @return the value in the cells
418  */
419 u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells);
420 
421 /**
422  * Look up a 64-bit integer property in a node and return it. The property
423  * must have at least 8 bytes of data (2 cells). The first two cells are
424  * concatenated to form a 8 bytes value, where the first cell is top half and
425  * the second cell is bottom half.
426  *
427  * @param blob	FDT blob
428  * @param node	node to examine
429  * @param prop_name	name of property to find
430  * @param default_val	default value to return if the property is not found
431  * @return integer value, if found, or default_val if not
432  */
433 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
434 		uint64_t default_val);
435 
436 /**
437  * Checks whether a node is enabled.
438  * This looks for a 'status' property. If this exists, then returns 1 if
439  * the status is 'ok' and 0 otherwise. If there is no status property,
440  * it returns 1 on the assumption that anything mentioned should be enabled
441  * by default.
442  *
443  * @param blob	FDT blob
444  * @param node	node to examine
445  * @return integer value 0 (not enabled) or 1 (enabled)
446  */
447 int fdtdec_get_is_enabled(const void *blob, int node);
448 
449 /**
450  * Make sure we have a valid fdt available to control U-Boot.
451  *
452  * If not, a message is printed to the console if the console is ready.
453  *
454  * @return 0 if all ok, -1 if not
455  */
456 int fdtdec_prepare_fdt(void);
457 
458 /**
459  * Checks that we have a valid fdt available to control U-Boot.
460 
461  * However, if not then for the moment nothing is done, since this function
462  * is called too early to panic().
463  *
464  * @returns 0
465  */
466 int fdtdec_check_fdt(void);
467 
468 /**
469  * Find the nodes for a peripheral and return a list of them in the correct
470  * order. This is used to enumerate all the peripherals of a certain type.
471  *
472  * To use this, optionally set up a /aliases node with alias properties for
473  * a peripheral. For example, for usb you could have:
474  *
475  * aliases {
476  *		usb0 = "/ehci@c5008000";
477  *		usb1 = "/ehci@c5000000";
478  * };
479  *
480  * Pass "usb" as the name to this function and will return a list of two
481  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
482  *
483  * All nodes returned will match the compatible ID, as it is assumed that
484  * all peripherals use the same driver.
485  *
486  * If no alias node is found, then the node list will be returned in the
487  * order found in the fdt. If the aliases mention a node which doesn't
488  * exist, then this will be ignored. If nodes are found with no aliases,
489  * they will be added in any order.
490  *
491  * If there is a gap in the aliases, then this function return a 0 node at
492  * that position. The return value will also count these gaps.
493  *
494  * This function checks node properties and will not return nodes which are
495  * marked disabled (status = "disabled").
496  *
497  * @param blob		FDT blob to use
498  * @param name		Root name of alias to search for
499  * @param id		Compatible ID to look for
500  * @param node_list	Place to put list of found nodes
501  * @param maxcount	Maximum number of nodes to find
502  * @return number of nodes found on success, FTD_ERR_... on error
503  */
504 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
505 			enum fdt_compat_id id, int *node_list, int maxcount);
506 
507 /*
508  * This function is similar to fdtdec_find_aliases_for_id() except that it
509  * adds to the node_list that is passed in. Any 0 elements are considered
510  * available for allocation - others are considered already used and are
511  * skipped.
512  *
513  * You can use this by calling fdtdec_find_aliases_for_id() with an
514  * uninitialised array, then setting the elements that are returned to -1,
515  * say, then calling this function, perhaps with a different compat id.
516  * Any elements you get back that are >0 are new nodes added by the call
517  * to this function.
518  *
519  * Note that if you have some nodes with aliases and some without, you are
520  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
521  * one compat_id may fill in positions for which you have aliases defined
522  * for another compat_id. When you later call *this* function with the second
523  * compat_id, the alias positions may already be used. A debug warning may
524  * be generated in this case, but it is safest to define aliases for all
525  * nodes when you care about the ordering.
526  */
527 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
528 			enum fdt_compat_id id, int *node_list, int maxcount);
529 
530 /**
531  * Get the alias sequence number of a node
532  *
533  * This works out whether a node is pointed to by an alias, and if so, the
534  * sequence number of that alias. Aliases are of the form <base><num> where
535  * <num> is the sequence number. For example spi2 would be sequence number
536  * 2.
537  *
538  * @param blob		Device tree blob (if NULL, then error is returned)
539  * @param base		Base name for alias (before the underscore)
540  * @param node		Node to look up
541  * @param seqp		This is set to the sequence number if one is found,
542  *			but otherwise the value is left alone
543  * @return 0 if a sequence was found, -ve if not
544  */
545 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
546 			 int *seqp);
547 
548 /**
549  * Get the offset of the given chosen node
550  *
551  * This looks up a property in /chosen containing the path to another node,
552  * then finds the offset of that node.
553  *
554  * @param blob		Device tree blob (if NULL, then error is returned)
555  * @param name		Property name, e.g. "stdout-path"
556  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
557  */
558 int fdtdec_get_chosen_node(const void *blob, const char *name);
559 
560 /*
561  * Get the name for a compatible ID
562  *
563  * @param id		Compatible ID to look for
564  * @return compatible string for that id
565  */
566 const char *fdtdec_get_compatible(enum fdt_compat_id id);
567 
568 /* Look up a phandle and follow it to its node. Then return the offset
569  * of that node.
570  *
571  * @param blob		FDT blob
572  * @param node		node to examine
573  * @param prop_name	name of property to find
574  * @return node offset if found, -ve error code on error
575  */
576 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
577 
578 /**
579  * Look up a property in a node and return its contents in an integer
580  * array of given length. The property must have at least enough data for
581  * the array (4*count bytes). It may have more, but this will be ignored.
582  *
583  * @param blob		FDT blob
584  * @param node		node to examine
585  * @param prop_name	name of property to find
586  * @param array		array to fill with data
587  * @param count		number of array elements
588  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
589  *		or -FDT_ERR_BADLAYOUT if not enough data
590  */
591 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
592 		u32 *array, int count);
593 
594 /**
595  * Look up a property in a node and return its contents in an integer
596  * array of given length. The property must exist but may have less data that
597  * expected (4*count bytes). It may have more, but this will be ignored.
598  *
599  * @param blob		FDT blob
600  * @param node		node to examine
601  * @param prop_name	name of property to find
602  * @param array		array to fill with data
603  * @param count		number of array elements
604  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
605  *		property is not found
606  */
607 int fdtdec_get_int_array_count(const void *blob, int node,
608 			       const char *prop_name, u32 *array, int count);
609 
610 /**
611  * Look up a property in a node and return a pointer to its contents as a
612  * unsigned int array of given length. The property must have at least enough
613  * data for the array ('count' cells). It may have more, but this will be
614  * ignored. The data is not copied.
615  *
616  * Note that you must access elements of the array with fdt32_to_cpu(),
617  * since the elements will be big endian even on a little endian machine.
618  *
619  * @param blob		FDT blob
620  * @param node		node to examine
621  * @param prop_name	name of property to find
622  * @param count		number of array elements
623  * @return pointer to array if found, or NULL if the property is not
624  *		found or there is not enough data
625  */
626 const u32 *fdtdec_locate_array(const void *blob, int node,
627 			       const char *prop_name, int count);
628 
629 /**
630  * Look up a boolean property in a node and return it.
631  *
632  * A boolean properly is true if present in the device tree and false if not
633  * present, regardless of its value.
634  *
635  * @param blob	FDT blob
636  * @param node	node to examine
637  * @param prop_name	name of property to find
638  * @return 1 if the properly is present; 0 if it isn't present
639  */
640 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
641 
642 /**
643  * Look in the FDT for a config item with the given name and return its value
644  * as a 32-bit integer. The property must have at least 4 bytes of data. The
645  * value of the first cell is returned.
646  *
647  * @param blob		FDT blob to use
648  * @param prop_name	Node property name
649  * @param default_val	default value to return if the property is not found
650  * @return integer value, if found, or default_val if not
651  */
652 int fdtdec_get_config_int(const void *blob, const char *prop_name,
653 		int default_val);
654 
655 /**
656  * Look in the FDT for a config item with the given name
657  * and return whether it exists.
658  *
659  * @param blob		FDT blob
660  * @param prop_name	property name to look up
661  * @return 1, if it exists, or 0 if not
662  */
663 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
664 
665 /**
666  * Look in the FDT for a config item with the given name and return its value
667  * as a string.
668  *
669  * @param blob          FDT blob
670  * @param prop_name     property name to look up
671  * @returns property string, NULL on error.
672  */
673 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
674 
675 /*
676  * Look up a property in a node and return its contents in a byte
677  * array of given length. The property must have at least enough data for
678  * the array (count bytes). It may have more, but this will be ignored.
679  *
680  * @param blob		FDT blob
681  * @param node		node to examine
682  * @param prop_name	name of property to find
683  * @param array		array to fill with data
684  * @param count		number of array elements
685  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
686  *		or -FDT_ERR_BADLAYOUT if not enough data
687  */
688 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
689 		u8 *array, int count);
690 
691 /**
692  * Look up a property in a node and return a pointer to its contents as a
693  * byte array of given length. The property must have at least enough data
694  * for the array (count bytes). It may have more, but this will be ignored.
695  * The data is not copied.
696  *
697  * @param blob		FDT blob
698  * @param node		node to examine
699  * @param prop_name	name of property to find
700  * @param count		number of array elements
701  * @return pointer to byte array if found, or NULL if the property is not
702  *		found or there is not enough data
703  */
704 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
705 			     const char *prop_name, int count);
706 
707 /**
708  * Look up a property in a node which contains a memory region address and
709  * size. Then return a pointer to this address.
710  *
711  * The property must hold one address with a length. This is only tested on
712  * 32-bit machines.
713  *
714  * @param blob		FDT blob
715  * @param node		node to examine
716  * @param prop_name	name of property to find
717  * @param basep		Returns base address of region
718  * @param size		Returns size of region
719  * @return 0 if ok, -1 on error (property not found)
720  */
721 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
722 			 fdt_addr_t *basep, fdt_size_t *sizep);
723 
724 enum fmap_compress_t {
725 	FMAP_COMPRESS_NONE,
726 	FMAP_COMPRESS_LZO,
727 };
728 
729 enum fmap_hash_t {
730 	FMAP_HASH_NONE,
731 	FMAP_HASH_SHA1,
732 	FMAP_HASH_SHA256,
733 };
734 
735 /* A flash map entry, containing an offset and length */
736 struct fmap_entry {
737 	uint32_t offset;
738 	uint32_t length;
739 	uint32_t used;			/* Number of bytes used in region */
740 	enum fmap_compress_t compress_algo;	/* Compression type */
741 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
742 	const uint8_t *hash;			/* Hash value */
743 	int hash_size;				/* Hash size */
744 };
745 
746 /**
747  * Read a flash entry from the fdt
748  *
749  * @param blob		FDT blob
750  * @param node		Offset of node to read
751  * @param name		Name of node being read
752  * @param entry		Place to put offset and size of this node
753  * @return 0 if ok, -ve on error
754  */
755 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
756 			   struct fmap_entry *entry);
757 
758 /**
759  * Obtain an indexed resource from a device property.
760  *
761  * @param fdt		FDT blob
762  * @param node		node to examine
763  * @param property	name of the property to parse
764  * @param index		index of the resource to retrieve
765  * @param res		returns the resource
766  * @return 0 if ok, negative on error
767  */
768 int fdt_get_resource(const void *fdt, int node, const char *property,
769 		     unsigned int index, struct fdt_resource *res);
770 
771 /**
772  * Obtain a named resource from a device property.
773  *
774  * Look up the index of the name in a list of strings and return the resource
775  * at that index.
776  *
777  * @param fdt		FDT blob
778  * @param node		node to examine
779  * @param property	name of the property to parse
780  * @param prop_names	name of the property containing the list of names
781  * @param name		the name of the entry to look up
782  * @param res		returns the resource
783  */
784 int fdt_get_named_resource(const void *fdt, int node, const char *property,
785 			   const char *prop_names, const char *name,
786 			   struct fdt_resource *res);
787 
788 /**
789  * Decode a named region within a memory bank of a given type.
790  *
791  * This function handles selection of a memory region. The region is
792  * specified as an offset/size within a particular type of memory.
793  *
794  * The properties used are:
795  *
796  *	<mem_type>-memory<suffix> for the name of the memory bank
797  *	<mem_type>-offset<suffix> for the offset in that bank
798  *
799  * The property value must have an offset and a size. The function checks
800  * that the region is entirely within the memory bank.5
801  *
802  * @param blob		FDT blob
803  * @param node		Node containing the properties (-1 for /config)
804  * @param mem_type	Type of memory to use, which is a name, such as
805  *			"u-boot" or "kernel".
806  * @param suffix	String to append to the memory/offset
807  *			property names
808  * @param basep		Returns base of region
809  * @param sizep		Returns size of region
810  * @return 0 if OK, -ive on error
811  */
812 int fdtdec_decode_memory_region(const void *blob, int node,
813 				const char *mem_type, const char *suffix,
814 				fdt_addr_t *basep, fdt_size_t *sizep);
815 
816 /* Display timings from linux include/video/display_timing.h */
817 enum display_flags {
818 	DISPLAY_FLAGS_HSYNC_LOW		= 1 << 0,
819 	DISPLAY_FLAGS_HSYNC_HIGH	= 1 << 1,
820 	DISPLAY_FLAGS_VSYNC_LOW		= 1 << 2,
821 	DISPLAY_FLAGS_VSYNC_HIGH	= 1 << 3,
822 
823 	/* data enable flag */
824 	DISPLAY_FLAGS_DE_LOW		= 1 << 4,
825 	DISPLAY_FLAGS_DE_HIGH		= 1 << 5,
826 	/* drive data on pos. edge */
827 	DISPLAY_FLAGS_PIXDATA_POSEDGE	= 1 << 6,
828 	/* drive data on neg. edge */
829 	DISPLAY_FLAGS_PIXDATA_NEGEDGE	= 1 << 7,
830 	DISPLAY_FLAGS_INTERLACED	= 1 << 8,
831 	DISPLAY_FLAGS_DOUBLESCAN	= 1 << 9,
832 	DISPLAY_FLAGS_DOUBLECLK		= 1 << 10,
833 };
834 
835 /*
836  * A single signal can be specified via a range of minimal and maximal values
837  * with a typical value, that lies somewhere inbetween.
838  */
839 struct timing_entry {
840 	u32 min;
841 	u32 typ;
842 	u32 max;
843 };
844 
845 /*
846  * Single "mode" entry. This describes one set of signal timings a display can
847  * have in one setting. This struct can later be converted to struct videomode
848  * (see include/video/videomode.h). As each timing_entry can be defined as a
849  * range, one struct display_timing may become multiple struct videomodes.
850  *
851  * Example: hsync active high, vsync active low
852  *
853  *				    Active Video
854  * Video  ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
855  *	  |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
856  *	  |	     |	 porch  |		     |	 porch	 |
857  *
858  * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯
859  *
860  * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________
861  */
862 struct display_timing {
863 	struct timing_entry pixelclock;
864 
865 	struct timing_entry hactive;		/* hor. active video */
866 	struct timing_entry hfront_porch;	/* hor. front porch */
867 	struct timing_entry hback_porch;	/* hor. back porch */
868 	struct timing_entry hsync_len;		/* hor. sync len */
869 
870 	struct timing_entry vactive;		/* ver. active video */
871 	struct timing_entry vfront_porch;	/* ver. front porch */
872 	struct timing_entry vback_porch;	/* ver. back porch */
873 	struct timing_entry vsync_len;		/* ver. sync len */
874 
875 	enum display_flags flags;		/* display flags */
876 };
877 
878 /**
879  * fdtdec_decode_display_timing() - decode display timings
880  *
881  * Decode display timings from the supplied 'display-timings' node.
882  * See doc/device-tree-bindings/video/display-timing.txt for binding
883  * information.
884  *
885  * @param blob		FDT blob
886  * @param node		'display-timing' node containing the timing subnodes
887  * @param index		Index number to read (0=first timing subnode)
888  * @param config	Place to put timings
889  * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
890  */
891 int fdtdec_decode_display_timing(const void *blob, int node, int index,
892 				 struct display_timing *config);
893 /**
894  * Set up the device tree ready for use
895  */
896 int fdtdec_setup(void);
897 
898 #endif
899