xref: /openbmc/u-boot/include/fdtdec.h (revision b8098bc1)
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 typedef phys_addr_t fdt_addr_t;
25 typedef phys_size_t fdt_size_t;
26 #ifdef CONFIG_PHYS_64BIT
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 #define FDT_ADDR_T_NONE (-1U)
32 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
33 #define fdt_size_to_cpu(reg) be32_to_cpu(reg)
34 #endif
35 
36 /* Information obtained about memory from the FDT */
37 struct fdt_memory {
38 	fdt_addr_t start;
39 	fdt_addr_t end;
40 };
41 
42 #ifdef CONFIG_SPL_BUILD
43 #define SPL_BUILD	1
44 #else
45 #define SPL_BUILD	0
46 #endif
47 
48 #ifdef CONFIG_OF_CONTROL
49 # if defined(CONFIG_SPL_BUILD) && defined(SPL_DISABLE_OF_CONTROL)
50 #  define OF_CONTROL 0
51 # else
52 #  define OF_CONTROL 1
53 # endif
54 #else
55 # define OF_CONTROL 0
56 #endif
57 
58 /*
59  * Information about a resource. start is the first address of the resource
60  * and end is the last address (inclusive). The length of the resource will
61  * be equal to: end - start + 1.
62  */
63 struct fdt_resource {
64 	fdt_addr_t start;
65 	fdt_addr_t end;
66 };
67 
68 enum fdt_pci_space {
69 	FDT_PCI_SPACE_CONFIG = 0,
70 	FDT_PCI_SPACE_IO = 0x01000000,
71 	FDT_PCI_SPACE_MEM32 = 0x02000000,
72 	FDT_PCI_SPACE_MEM64 = 0x03000000,
73 	FDT_PCI_SPACE_MEM32_PREF = 0x42000000,
74 	FDT_PCI_SPACE_MEM64_PREF = 0x43000000,
75 };
76 
77 #define FDT_PCI_ADDR_CELLS	3
78 #define FDT_PCI_SIZE_CELLS	2
79 #define FDT_PCI_REG_SIZE	\
80 	((FDT_PCI_ADDR_CELLS + FDT_PCI_SIZE_CELLS) * sizeof(u32))
81 
82 /*
83  * The Open Firmware spec defines PCI physical address as follows:
84  *
85  *          bits# 31 .... 24 23 .... 16 15 .... 08 07 .... 00
86  *
87  * phys.hi  cell:  npt000ss   bbbbbbbb   dddddfff   rrrrrrrr
88  * phys.mid cell:  hhhhhhhh   hhhhhhhh   hhhhhhhh   hhhhhhhh
89  * phys.lo  cell:  llllllll   llllllll   llllllll   llllllll
90  *
91  * where:
92  *
93  * n:        is 0 if the address is relocatable, 1 otherwise
94  * p:        is 1 if addressable region is prefetchable, 0 otherwise
95  * t:        is 1 if the address is aliased (for non-relocatable I/O) below 1MB
96  *           (for Memory), or below 64KB (for relocatable I/O)
97  * ss:       is the space code, denoting the address space
98  * bbbbbbbb: is the 8-bit Bus Number
99  * ddddd:    is the 5-bit Device Number
100  * fff:      is the 3-bit Function Number
101  * rrrrrrrr: is the 8-bit Register Number
102  * hhhhhhhh: is a 32-bit unsigned number
103  * llllllll: is a 32-bit unsigned number
104  */
105 struct fdt_pci_addr {
106 	u32	phys_hi;
107 	u32	phys_mid;
108 	u32	phys_lo;
109 };
110 
111 /**
112  * Compute the size of a resource.
113  *
114  * @param res	the resource to operate on
115  * @return the size of the resource
116  */
117 static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
118 {
119 	return res->end - res->start + 1;
120 }
121 
122 /**
123  * Compat types that we know about and for which we might have drivers.
124  * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
125  * within drivers.
126  */
127 enum fdt_compat_id {
128 	COMPAT_UNKNOWN,
129 	COMPAT_NVIDIA_TEGRA20_EMC,	/* Tegra20 memory controller */
130 	COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
131 	COMPAT_NVIDIA_TEGRA20_KBC,	/* Tegra20 Keyboard */
132 	COMPAT_NVIDIA_TEGRA20_NAND,	/* Tegra2 NAND controller */
133 	COMPAT_NVIDIA_TEGRA20_PWM,	/* Tegra 2 PWM controller */
134 	COMPAT_NVIDIA_TEGRA124_DC,	/* Tegra 124 Display controller */
135 	COMPAT_NVIDIA_TEGRA124_SOR,	/* Tegra 124 Serial Output Resource */
136 	COMPAT_NVIDIA_TEGRA124_PMC,	/* Tegra 124 power mgmt controller */
137 	COMPAT_NVIDIA_TEGRA20_DC,	/* Tegra 2 Display controller */
138 	COMPAT_NVIDIA_TEGRA210_SDMMC,	/* Tegra210 SDMMC controller */
139 	COMPAT_NVIDIA_TEGRA124_SDMMC,	/* Tegra124 SDMMC controller */
140 	COMPAT_NVIDIA_TEGRA30_SDMMC,	/* Tegra30 SDMMC controller */
141 	COMPAT_NVIDIA_TEGRA20_SDMMC,	/* Tegra20 SDMMC controller */
142 	COMPAT_NVIDIA_TEGRA124_PCIE,	/* Tegra 124 PCIe controller */
143 	COMPAT_NVIDIA_TEGRA30_PCIE,	/* Tegra 30 PCIe controller */
144 	COMPAT_NVIDIA_TEGRA20_PCIE,	/* Tegra 20 PCIe controller */
145 	COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
146 					/* Tegra124 XUSB pad controller */
147 	COMPAT_NVIDIA_TEGRA210_XUSB_PADCTL,
148 					/* Tegra210 XUSB pad controller */
149 	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
150 	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
151 	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */
152 	COMPAT_SAMSUNG_EXYNOS5_SOUND,	/* Exynos Sound */
153 	COMPAT_WOLFSON_WM8994_CODEC,	/* Wolfson WM8994 Sound Codec */
154 	COMPAT_GOOGLE_CROS_EC_KEYB,	/* Google CROS_EC Keyboard */
155 	COMPAT_SAMSUNG_EXYNOS_USB_PHY,	/* Exynos phy controller for usb2.0 */
156 	COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
157 	COMPAT_SAMSUNG_EXYNOS_TMU,	/* Exynos TMU */
158 	COMPAT_SAMSUNG_EXYNOS_FIMD,	/* Exynos Display controller */
159 	COMPAT_SAMSUNG_EXYNOS_MIPI_DSI,	/* Exynos mipi dsi */
160 	COMPAT_SAMSUNG_EXYNOS5_DP,	/* Exynos Display port controller */
161 	COMPAT_SAMSUNG_EXYNOS_DWMMC,	/* Exynos DWMMC controller */
162 	COMPAT_SAMSUNG_EXYNOS_MMC,	/* Exynos MMC controller */
163 	COMPAT_SAMSUNG_EXYNOS_SERIAL,	/* Exynos UART */
164 	COMPAT_MAXIM_MAX77686_PMIC,	/* MAX77686 PMIC */
165 	COMPAT_GENERIC_SPI_FLASH,	/* Generic SPI Flash chip */
166 	COMPAT_MAXIM_98095_CODEC,	/* MAX98095 Codec */
167 	COMPAT_INFINEON_SLB9635_TPM,	/* Infineon SLB9635 TPM */
168 	COMPAT_INFINEON_SLB9645_TPM,	/* Infineon SLB9645 TPM */
169 	COMPAT_SAMSUNG_EXYNOS5_I2C,	/* Exynos5 High Speed I2C Controller */
170 	COMPAT_SANDBOX_LCD_SDL,		/* Sandbox LCD emulation with SDL */
171 	COMPAT_SAMSUNG_EXYNOS_SYSMMU,	/* Exynos sysmmu */
172 	COMPAT_INTEL_MICROCODE,		/* Intel microcode update */
173 	COMPAT_MEMORY_SPD,		/* Memory SPD information */
174 	COMPAT_INTEL_PANTHERPOINT_AHCI,	/* Intel Pantherpoint AHCI */
175 	COMPAT_INTEL_MODEL_206AX,	/* Intel Model 206AX CPU */
176 	COMPAT_INTEL_GMA,		/* Intel Graphics Media Accelerator */
177 	COMPAT_AMS_AS3722,		/* AMS AS3722 PMIC */
178 	COMPAT_INTEL_ICH_SPI,		/* Intel ICH7/9 SPI controller */
179 	COMPAT_INTEL_QRK_MRC,		/* Intel Quark MRC */
180 	COMPAT_INTEL_X86_PINCTRL,	/* Intel ICH7/9 pin control */
181 	COMPAT_SOCIONEXT_XHCI,		/* Socionext UniPhier xHCI */
182 	COMPAT_INTEL_PCH,		/* Intel PCH */
183 	COMPAT_INTEL_IRQ_ROUTER,	/* Intel Interrupt Router */
184 	COMPAT_ALTERA_SOCFPGA_DWMAC,	/* SoCFPGA Ethernet controller */
185 	COMPAT_INTEL_BAYTRAIL_FSP,	/* Intel Bay Trail FSP */
186 	COMPAT_INTEL_BAYTRAIL_FSP_MDP,	/* Intel FSP memory-down params */
187 
188 	COMPAT_COUNT,
189 };
190 
191 #define MAX_PHANDLE_ARGS 16
192 struct fdtdec_phandle_args {
193 	int node;
194 	int args_count;
195 	uint32_t args[MAX_PHANDLE_ARGS];
196 };
197 
198 /**
199  * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
200  *
201  * This function is useful to parse lists of phandles and their arguments.
202  *
203  * Example:
204  *
205  * phandle1: node1 {
206  *	#list-cells = <2>;
207  * }
208  *
209  * phandle2: node2 {
210  *	#list-cells = <1>;
211  * }
212  *
213  * node3 {
214  *	list = <&phandle1 1 2 &phandle2 3>;
215  * }
216  *
217  * To get a device_node of the `node2' node you may call this:
218  * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
219  *				  &args);
220  *
221  * (This function is a modified version of __of_parse_phandle_with_args() from
222  * Linux 3.18)
223  *
224  * @blob:	Pointer to device tree
225  * @src_node:	Offset of device tree node containing a list
226  * @list_name:	property name that contains a list
227  * @cells_name:	property name that specifies the phandles' arguments count,
228  *		or NULL to use @cells_count
229  * @cells_count: Cell count to use if @cells_name is NULL
230  * @index:	index of a phandle to parse out
231  * @out_args:	optional pointer to output arguments structure (will be filled)
232  * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
233  *	@list_name does not exist, a phandle was not found, @cells_name
234  *	could not be found, the arguments were truncated or there were too
235  *	many arguments.
236  *
237  */
238 int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
239 				   const char *list_name,
240 				   const char *cells_name,
241 				   int cell_count, int index,
242 				   struct fdtdec_phandle_args *out_args);
243 
244 /**
245  * Find the next numbered alias for a peripheral. This is used to enumerate
246  * all the peripherals of a certain type.
247  *
248  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
249  * this function will return a pointer to the node the alias points to, and
250  * then update *upto to 1. Next time you call this function, the next node
251  * will be returned.
252  *
253  * All nodes returned will match the compatible ID, as it is assumed that
254  * all peripherals use the same driver.
255  *
256  * @param blob		FDT blob to use
257  * @param name		Root name of alias to search for
258  * @param id		Compatible ID to look for
259  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
260  */
261 int fdtdec_next_alias(const void *blob, const char *name,
262 		enum fdt_compat_id id, int *upto);
263 
264 /**
265  * Find the compatible ID for a given node.
266  *
267  * Generally each node has at least one compatible string attached to it.
268  * This function looks through our list of known compatible strings and
269  * returns the corresponding ID which matches the compatible string.
270  *
271  * @param blob		FDT blob to use
272  * @param node		Node containing compatible string to find
273  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
274  */
275 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
276 
277 /**
278  * Find the next compatible node for a peripheral.
279  *
280  * Do the first call with node = 0. This function will return a pointer to
281  * the next compatible node. Next time you call this function, pass the
282  * value returned, and the next node will be provided.
283  *
284  * @param blob		FDT blob to use
285  * @param node		Start node for search
286  * @param id		Compatible ID to look for (enum fdt_compat_id)
287  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
288  */
289 int fdtdec_next_compatible(const void *blob, int node,
290 		enum fdt_compat_id id);
291 
292 /**
293  * Find the next compatible subnode for a peripheral.
294  *
295  * Do the first call with node set to the parent and depth = 0. This
296  * function will return the offset of the next compatible node. Next time
297  * you call this function, pass the node value returned last time, with
298  * depth unchanged, and the next node will be provided.
299  *
300  * @param blob		FDT blob to use
301  * @param node		Start node for search
302  * @param id		Compatible ID to look for (enum fdt_compat_id)
303  * @param depthp	Current depth (set to 0 before first call)
304  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
305  */
306 int fdtdec_next_compatible_subnode(const void *blob, int node,
307 		enum fdt_compat_id id, int *depthp);
308 
309 /**
310  * Look up an address property in a node and return it as an address.
311  * The property must hold either one address with no trailing data or
312  * one address with a length. This is only tested on 32-bit machines.
313  *
314  * @param blob	FDT blob
315  * @param node	node to examine
316  * @param prop_name	name of property to find
317  * @return address, if found, or FDT_ADDR_T_NONE if not
318  */
319 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
320 		const char *prop_name);
321 
322 /**
323  * Look up an address property in a node and return it as an address.
324  * The property must hold one address with a length. This is only tested
325  * on 32-bit machines.
326  *
327  * @param blob	FDT blob
328  * @param node	node to examine
329  * @param prop_name	name of property to find
330  * @return address, if found, or FDT_ADDR_T_NONE if not
331  */
332 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
333 		const char *prop_name, fdt_size_t *sizep);
334 
335 /**
336  * Look at an address property in a node and return the pci address which
337  * corresponds to the given type in the form of fdt_pci_addr.
338  * The property must hold one fdt_pci_addr with a lengh.
339  *
340  * @param blob		FDT blob
341  * @param node		node to examine
342  * @param type		pci address type (FDT_PCI_SPACE_xxx)
343  * @param prop_name	name of property to find
344  * @param addr		returns pci address in the form of fdt_pci_addr
345  * @return 0 if ok, -ENOENT if the property did not exist, -EINVAL if the
346  *		format of the property was invalid, -ENXIO if the requested
347  *		address type was not found
348  */
349 int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
350 		const char *prop_name, struct fdt_pci_addr *addr);
351 
352 /**
353  * Look at the compatible property of a device node that represents a PCI
354  * device and extract pci vendor id and device id from it.
355  *
356  * @param blob		FDT blob
357  * @param node		node to examine
358  * @param vendor	vendor id of the pci device
359  * @param device	device id of the pci device
360  * @return 0 if ok, negative on error
361  */
362 int fdtdec_get_pci_vendev(const void *blob, int node,
363 		u16 *vendor, u16 *device);
364 
365 /**
366  * Look at the pci address of a device node that represents a PCI device
367  * and parse the bus, device and function number from it. For some cases
368  * like the bus number encoded in reg property is not correct after pci
369  * enumeration, this function looks through the node's compatible strings
370  * to get these numbers extracted instead.
371  *
372  * @param blob		FDT blob
373  * @param node		node to examine
374  * @param addr		pci address in the form of fdt_pci_addr
375  * @param bdf		returns bus, device, function triplet
376  * @return 0 if ok, negative on error
377  */
378 int fdtdec_get_pci_bdf(const void *blob, int node,
379 		struct fdt_pci_addr *addr, pci_dev_t *bdf);
380 
381 /**
382  * Look at the pci address of a device node that represents a PCI device
383  * and return base address of the pci device's registers.
384  *
385  * @param blob		FDT blob
386  * @param node		node to examine
387  * @param addr		pci address in the form of fdt_pci_addr
388  * @param bar		returns base address of the pci device's registers
389  * @return 0 if ok, negative on error
390  */
391 int fdtdec_get_pci_bar32(const void *blob, int node,
392 		struct fdt_pci_addr *addr, u32 *bar);
393 
394 /**
395  * Look up a 32-bit integer property in a node and return it. The property
396  * must have at least 4 bytes of data. The value of the first cell is
397  * returned.
398  *
399  * @param blob	FDT blob
400  * @param node	node to examine
401  * @param prop_name	name of property to find
402  * @param default_val	default value to return if the property is not found
403  * @return integer value, if found, or default_val if not
404  */
405 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
406 		s32 default_val);
407 
408 /**
409  * Get a variable-sized number from a property
410  *
411  * This reads a number from one or more cells.
412  *
413  * @param ptr	Pointer to property
414  * @param cells	Number of cells containing the number
415  * @return the value in the cells
416  */
417 u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells);
418 
419 /**
420  * Look up a 64-bit integer property in a node and return it. The property
421  * must have at least 8 bytes of data (2 cells). The first two cells are
422  * concatenated to form a 8 bytes value, where the first cell is top half and
423  * the second cell is bottom half.
424  *
425  * @param blob	FDT blob
426  * @param node	node to examine
427  * @param prop_name	name of property to find
428  * @param default_val	default value to return if the property is not found
429  * @return integer value, if found, or default_val if not
430  */
431 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
432 		uint64_t default_val);
433 
434 /**
435  * Checks whether a node is enabled.
436  * This looks for a 'status' property. If this exists, then returns 1 if
437  * the status is 'ok' and 0 otherwise. If there is no status property,
438  * it returns 1 on the assumption that anything mentioned should be enabled
439  * by default.
440  *
441  * @param blob	FDT blob
442  * @param node	node to examine
443  * @return integer value 0 (not enabled) or 1 (enabled)
444  */
445 int fdtdec_get_is_enabled(const void *blob, int node);
446 
447 /**
448  * Make sure we have a valid fdt available to control U-Boot.
449  *
450  * If not, a message is printed to the console if the console is ready.
451  *
452  * @return 0 if all ok, -1 if not
453  */
454 int fdtdec_prepare_fdt(void);
455 
456 /**
457  * Checks that we have a valid fdt available to control U-Boot.
458 
459  * However, if not then for the moment nothing is done, since this function
460  * is called too early to panic().
461  *
462  * @returns 0
463  */
464 int fdtdec_check_fdt(void);
465 
466 /**
467  * Find the nodes for a peripheral and return a list of them in the correct
468  * order. This is used to enumerate all the peripherals of a certain type.
469  *
470  * To use this, optionally set up a /aliases node with alias properties for
471  * a peripheral. For example, for usb you could have:
472  *
473  * aliases {
474  *		usb0 = "/ehci@c5008000";
475  *		usb1 = "/ehci@c5000000";
476  * };
477  *
478  * Pass "usb" as the name to this function and will return a list of two
479  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
480  *
481  * All nodes returned will match the compatible ID, as it is assumed that
482  * all peripherals use the same driver.
483  *
484  * If no alias node is found, then the node list will be returned in the
485  * order found in the fdt. If the aliases mention a node which doesn't
486  * exist, then this will be ignored. If nodes are found with no aliases,
487  * they will be added in any order.
488  *
489  * If there is a gap in the aliases, then this function return a 0 node at
490  * that position. The return value will also count these gaps.
491  *
492  * This function checks node properties and will not return nodes which are
493  * marked disabled (status = "disabled").
494  *
495  * @param blob		FDT blob to use
496  * @param name		Root name of alias to search for
497  * @param id		Compatible ID to look for
498  * @param node_list	Place to put list of found nodes
499  * @param maxcount	Maximum number of nodes to find
500  * @return number of nodes found on success, FTD_ERR_... on error
501  */
502 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
503 			enum fdt_compat_id id, int *node_list, int maxcount);
504 
505 /*
506  * This function is similar to fdtdec_find_aliases_for_id() except that it
507  * adds to the node_list that is passed in. Any 0 elements are considered
508  * available for allocation - others are considered already used and are
509  * skipped.
510  *
511  * You can use this by calling fdtdec_find_aliases_for_id() with an
512  * uninitialised array, then setting the elements that are returned to -1,
513  * say, then calling this function, perhaps with a different compat id.
514  * Any elements you get back that are >0 are new nodes added by the call
515  * to this function.
516  *
517  * Note that if you have some nodes with aliases and some without, you are
518  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
519  * one compat_id may fill in positions for which you have aliases defined
520  * for another compat_id. When you later call *this* function with the second
521  * compat_id, the alias positions may already be used. A debug warning may
522  * be generated in this case, but it is safest to define aliases for all
523  * nodes when you care about the ordering.
524  */
525 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
526 			enum fdt_compat_id id, int *node_list, int maxcount);
527 
528 /**
529  * Get the alias sequence number of a node
530  *
531  * This works out whether a node is pointed to by an alias, and if so, the
532  * sequence number of that alias. Aliases are of the form <base><num> where
533  * <num> is the sequence number. For example spi2 would be sequence number
534  * 2.
535  *
536  * @param blob		Device tree blob (if NULL, then error is returned)
537  * @param base		Base name for alias (before the underscore)
538  * @param node		Node to look up
539  * @param seqp		This is set to the sequence number if one is found,
540  *			but otherwise the value is left alone
541  * @return 0 if a sequence was found, -ve if not
542  */
543 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
544 			 int *seqp);
545 
546 /**
547  * Get the offset of the given chosen node
548  *
549  * This looks up a property in /chosen containing the path to another node,
550  * then finds the offset of that node.
551  *
552  * @param blob		Device tree blob (if NULL, then error is returned)
553  * @param name		Property name, e.g. "stdout-path"
554  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
555  */
556 int fdtdec_get_chosen_node(const void *blob, const char *name);
557 
558 /*
559  * Get the name for a compatible ID
560  *
561  * @param id		Compatible ID to look for
562  * @return compatible string for that id
563  */
564 const char *fdtdec_get_compatible(enum fdt_compat_id id);
565 
566 /* Look up a phandle and follow it to its node. Then return the offset
567  * of that node.
568  *
569  * @param blob		FDT blob
570  * @param node		node to examine
571  * @param prop_name	name of property to find
572  * @return node offset if found, -ve error code on error
573  */
574 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
575 
576 /**
577  * Look up a property in a node and return its contents in an integer
578  * array of given length. The property must have at least enough data for
579  * the array (4*count bytes). It may have more, but this will be ignored.
580  *
581  * @param blob		FDT blob
582  * @param node		node to examine
583  * @param prop_name	name of property to find
584  * @param array		array to fill with data
585  * @param count		number of array elements
586  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
587  *		or -FDT_ERR_BADLAYOUT if not enough data
588  */
589 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
590 		u32 *array, int count);
591 
592 /**
593  * Look up a property in a node and return its contents in an integer
594  * array of given length. The property must exist but may have less data that
595  * expected (4*count bytes). It may have more, but this will be ignored.
596  *
597  * @param blob		FDT blob
598  * @param node		node to examine
599  * @param prop_name	name of property to find
600  * @param array		array to fill with data
601  * @param count		number of array elements
602  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
603  *		property is not found
604  */
605 int fdtdec_get_int_array_count(const void *blob, int node,
606 			       const char *prop_name, u32 *array, int count);
607 
608 /**
609  * Look up a property in a node and return a pointer to its contents as a
610  * unsigned int array of given length. The property must have at least enough
611  * data for the array ('count' cells). It may have more, but this will be
612  * ignored. The data is not copied.
613  *
614  * Note that you must access elements of the array with fdt32_to_cpu(),
615  * since the elements will be big endian even on a little endian machine.
616  *
617  * @param blob		FDT blob
618  * @param node		node to examine
619  * @param prop_name	name of property to find
620  * @param count		number of array elements
621  * @return pointer to array if found, or NULL if the property is not
622  *		found or there is not enough data
623  */
624 const u32 *fdtdec_locate_array(const void *blob, int node,
625 			       const char *prop_name, int count);
626 
627 /**
628  * Look up a boolean property in a node and return it.
629  *
630  * A boolean properly is true if present in the device tree and false if not
631  * present, regardless of its value.
632  *
633  * @param blob	FDT blob
634  * @param node	node to examine
635  * @param prop_name	name of property to find
636  * @return 1 if the properly is present; 0 if it isn't present
637  */
638 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
639 
640 /**
641  * Look in the FDT for a config item with the given name and return its value
642  * as a 32-bit integer. The property must have at least 4 bytes of data. The
643  * value of the first cell is returned.
644  *
645  * @param blob		FDT blob to use
646  * @param prop_name	Node property name
647  * @param default_val	default value to return if the property is not found
648  * @return integer value, if found, or default_val if not
649  */
650 int fdtdec_get_config_int(const void *blob, const char *prop_name,
651 		int default_val);
652 
653 /**
654  * Look in the FDT for a config item with the given name
655  * and return whether it exists.
656  *
657  * @param blob		FDT blob
658  * @param prop_name	property name to look up
659  * @return 1, if it exists, or 0 if not
660  */
661 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
662 
663 /**
664  * Look in the FDT for a config item with the given name and return its value
665  * as a string.
666  *
667  * @param blob          FDT blob
668  * @param prop_name     property name to look up
669  * @returns property string, NULL on error.
670  */
671 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
672 
673 /*
674  * Look up a property in a node and return its contents in a byte
675  * array of given length. The property must have at least enough data for
676  * the array (count bytes). It may have more, but this will be ignored.
677  *
678  * @param blob		FDT blob
679  * @param node		node to examine
680  * @param prop_name	name of property to find
681  * @param array		array to fill with data
682  * @param count		number of array elements
683  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
684  *		or -FDT_ERR_BADLAYOUT if not enough data
685  */
686 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
687 		u8 *array, int count);
688 
689 /**
690  * Look up a property in a node and return a pointer to its contents as a
691  * byte array of given length. The property must have at least enough data
692  * for the array (count bytes). It may have more, but this will be ignored.
693  * The data is not copied.
694  *
695  * @param blob		FDT blob
696  * @param node		node to examine
697  * @param prop_name	name of property to find
698  * @param count		number of array elements
699  * @return pointer to byte array if found, or NULL if the property is not
700  *		found or there is not enough data
701  */
702 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
703 			     const char *prop_name, int count);
704 
705 /**
706  * Look up a property in a node which contains a memory region address and
707  * size. Then return a pointer to this address.
708  *
709  * The property must hold one address with a length. This is only tested on
710  * 32-bit machines.
711  *
712  * @param blob		FDT blob
713  * @param node		node to examine
714  * @param prop_name	name of property to find
715  * @param basep		Returns base address of region
716  * @param size		Returns size of region
717  * @return 0 if ok, -1 on error (property not found)
718  */
719 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
720 			 fdt_addr_t *basep, fdt_size_t *sizep);
721 
722 enum fmap_compress_t {
723 	FMAP_COMPRESS_NONE,
724 	FMAP_COMPRESS_LZO,
725 };
726 
727 enum fmap_hash_t {
728 	FMAP_HASH_NONE,
729 	FMAP_HASH_SHA1,
730 	FMAP_HASH_SHA256,
731 };
732 
733 /* A flash map entry, containing an offset and length */
734 struct fmap_entry {
735 	uint32_t offset;
736 	uint32_t length;
737 	uint32_t used;			/* Number of bytes used in region */
738 	enum fmap_compress_t compress_algo;	/* Compression type */
739 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
740 	const uint8_t *hash;			/* Hash value */
741 	int hash_size;				/* Hash size */
742 };
743 
744 /**
745  * Read a flash entry from the fdt
746  *
747  * @param blob		FDT blob
748  * @param node		Offset of node to read
749  * @param name		Name of node being read
750  * @param entry		Place to put offset and size of this node
751  * @return 0 if ok, -ve on error
752  */
753 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
754 			   struct fmap_entry *entry);
755 
756 /**
757  * Obtain an indexed resource from a device property.
758  *
759  * @param fdt		FDT blob
760  * @param node		node to examine
761  * @param property	name of the property to parse
762  * @param index		index of the resource to retrieve
763  * @param res		returns the resource
764  * @return 0 if ok, negative on error
765  */
766 int fdt_get_resource(const void *fdt, int node, const char *property,
767 		     unsigned int index, struct fdt_resource *res);
768 
769 /**
770  * Obtain a named resource from a device property.
771  *
772  * Look up the index of the name in a list of strings and return the resource
773  * at that index.
774  *
775  * @param fdt		FDT blob
776  * @param node		node to examine
777  * @param property	name of the property to parse
778  * @param prop_names	name of the property containing the list of names
779  * @param name		the name of the entry to look up
780  * @param res		returns the resource
781  */
782 int fdt_get_named_resource(const void *fdt, int node, const char *property,
783 			   const char *prop_names, const char *name,
784 			   struct fdt_resource *res);
785 
786 /**
787  * Decode a named region within a memory bank of a given type.
788  *
789  * This function handles selection of a memory region. The region is
790  * specified as an offset/size within a particular type of memory.
791  *
792  * The properties used are:
793  *
794  *	<mem_type>-memory<suffix> for the name of the memory bank
795  *	<mem_type>-offset<suffix> for the offset in that bank
796  *
797  * The property value must have an offset and a size. The function checks
798  * that the region is entirely within the memory bank.5
799  *
800  * @param blob		FDT blob
801  * @param node		Node containing the properties (-1 for /config)
802  * @param mem_type	Type of memory to use, which is a name, such as
803  *			"u-boot" or "kernel".
804  * @param suffix	String to append to the memory/offset
805  *			property names
806  * @param basep		Returns base of region
807  * @param sizep		Returns size of region
808  * @return 0 if OK, -ive on error
809  */
810 int fdtdec_decode_memory_region(const void *blob, int node,
811 				const char *mem_type, const char *suffix,
812 				fdt_addr_t *basep, fdt_size_t *sizep);
813 
814 /* Display timings from linux include/video/display_timing.h */
815 enum display_flags {
816 	DISPLAY_FLAGS_HSYNC_LOW		= 1 << 0,
817 	DISPLAY_FLAGS_HSYNC_HIGH	= 1 << 1,
818 	DISPLAY_FLAGS_VSYNC_LOW		= 1 << 2,
819 	DISPLAY_FLAGS_VSYNC_HIGH	= 1 << 3,
820 
821 	/* data enable flag */
822 	DISPLAY_FLAGS_DE_LOW		= 1 << 4,
823 	DISPLAY_FLAGS_DE_HIGH		= 1 << 5,
824 	/* drive data on pos. edge */
825 	DISPLAY_FLAGS_PIXDATA_POSEDGE	= 1 << 6,
826 	/* drive data on neg. edge */
827 	DISPLAY_FLAGS_PIXDATA_NEGEDGE	= 1 << 7,
828 	DISPLAY_FLAGS_INTERLACED	= 1 << 8,
829 	DISPLAY_FLAGS_DOUBLESCAN	= 1 << 9,
830 	DISPLAY_FLAGS_DOUBLECLK		= 1 << 10,
831 };
832 
833 /*
834  * A single signal can be specified via a range of minimal and maximal values
835  * with a typical value, that lies somewhere inbetween.
836  */
837 struct timing_entry {
838 	u32 min;
839 	u32 typ;
840 	u32 max;
841 };
842 
843 /*
844  * Single "mode" entry. This describes one set of signal timings a display can
845  * have in one setting. This struct can later be converted to struct videomode
846  * (see include/video/videomode.h). As each timing_entry can be defined as a
847  * range, one struct display_timing may become multiple struct videomodes.
848  *
849  * Example: hsync active high, vsync active low
850  *
851  *				    Active Video
852  * Video  ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
853  *	  |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
854  *	  |	     |	 porch  |		     |	 porch	 |
855  *
856  * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯
857  *
858  * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________
859  */
860 struct display_timing {
861 	struct timing_entry pixelclock;
862 
863 	struct timing_entry hactive;		/* hor. active video */
864 	struct timing_entry hfront_porch;	/* hor. front porch */
865 	struct timing_entry hback_porch;	/* hor. back porch */
866 	struct timing_entry hsync_len;		/* hor. sync len */
867 
868 	struct timing_entry vactive;		/* ver. active video */
869 	struct timing_entry vfront_porch;	/* ver. front porch */
870 	struct timing_entry vback_porch;	/* ver. back porch */
871 	struct timing_entry vsync_len;		/* ver. sync len */
872 
873 	enum display_flags flags;		/* display flags */
874 };
875 
876 /**
877  * fdtdec_decode_display_timing() - decode display timings
878  *
879  * Decode display timings from the supplied 'display-timings' node.
880  * See doc/device-tree-bindings/video/display-timing.txt for binding
881  * information.
882  *
883  * @param blob		FDT blob
884  * @param node		'display-timing' node containing the timing subnodes
885  * @param index		Index number to read (0=first timing subnode)
886  * @param config	Place to put timings
887  * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
888  */
889 int fdtdec_decode_display_timing(const void *blob, int node, int index,
890 				 struct display_timing *config);
891 /**
892  * Set up the device tree ready for use
893  */
894 int fdtdec_setup(void);
895 
896 #endif
897