xref: /openbmc/u-boot/include/fdtdec.h (revision 9bbd2132e3af95ac225f3641b69bd129da11457f)
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 
185 	COMPAT_COUNT,
186 };
187 
188 #define MAX_PHANDLE_ARGS 16
189 struct fdtdec_phandle_args {
190 	int node;
191 	int args_count;
192 	uint32_t args[MAX_PHANDLE_ARGS];
193 };
194 
195 /**
196  * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
197  *
198  * This function is useful to parse lists of phandles and their arguments.
199  *
200  * Example:
201  *
202  * phandle1: node1 {
203  *	#list-cells = <2>;
204  * }
205  *
206  * phandle2: node2 {
207  *	#list-cells = <1>;
208  * }
209  *
210  * node3 {
211  *	list = <&phandle1 1 2 &phandle2 3>;
212  * }
213  *
214  * To get a device_node of the `node2' node you may call this:
215  * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
216  *				  &args);
217  *
218  * (This function is a modified version of __of_parse_phandle_with_args() from
219  * Linux 3.18)
220  *
221  * @blob:	Pointer to device tree
222  * @src_node:	Offset of device tree node containing a list
223  * @list_name:	property name that contains a list
224  * @cells_name:	property name that specifies the phandles' arguments count,
225  *		or NULL to use @cells_count
226  * @cells_count: Cell count to use if @cells_name is NULL
227  * @index:	index of a phandle to parse out
228  * @out_args:	optional pointer to output arguments structure (will be filled)
229  * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
230  *	@list_name does not exist, a phandle was not found, @cells_name
231  *	could not be found, the arguments were truncated or there were too
232  *	many arguments.
233  *
234  */
235 int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
236 				   const char *list_name,
237 				   const char *cells_name,
238 				   int cell_count, int index,
239 				   struct fdtdec_phandle_args *out_args);
240 
241 /**
242  * Find the next numbered alias for a peripheral. This is used to enumerate
243  * all the peripherals of a certain type.
244  *
245  * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
246  * this function will return a pointer to the node the alias points to, and
247  * then update *upto to 1. Next time you call this function, the next node
248  * will be returned.
249  *
250  * All nodes returned will match the compatible ID, as it is assumed that
251  * all peripherals use the same driver.
252  *
253  * @param blob		FDT blob to use
254  * @param name		Root name of alias to search for
255  * @param id		Compatible ID to look for
256  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
257  */
258 int fdtdec_next_alias(const void *blob, const char *name,
259 		enum fdt_compat_id id, int *upto);
260 
261 /**
262  * Find the compatible ID for a given node.
263  *
264  * Generally each node has at least one compatible string attached to it.
265  * This function looks through our list of known compatible strings and
266  * returns the corresponding ID which matches the compatible string.
267  *
268  * @param blob		FDT blob to use
269  * @param node		Node containing compatible string to find
270  * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
271  */
272 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
273 
274 /**
275  * Find the next compatible node for a peripheral.
276  *
277  * Do the first call with node = 0. This function will return a pointer to
278  * the next compatible node. Next time you call this function, pass the
279  * value returned, and the next node will be provided.
280  *
281  * @param blob		FDT blob to use
282  * @param node		Start node for search
283  * @param id		Compatible ID to look for (enum fdt_compat_id)
284  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
285  */
286 int fdtdec_next_compatible(const void *blob, int node,
287 		enum fdt_compat_id id);
288 
289 /**
290  * Find the next compatible subnode for a peripheral.
291  *
292  * Do the first call with node set to the parent and depth = 0. This
293  * function will return the offset of the next compatible node. Next time
294  * you call this function, pass the node value returned last time, with
295  * depth unchanged, and the next node will be provided.
296  *
297  * @param blob		FDT blob to use
298  * @param node		Start node for search
299  * @param id		Compatible ID to look for (enum fdt_compat_id)
300  * @param depthp	Current depth (set to 0 before first call)
301  * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
302  */
303 int fdtdec_next_compatible_subnode(const void *blob, int node,
304 		enum fdt_compat_id id, int *depthp);
305 
306 /**
307  * Look up an address property in a node and return it as an address.
308  * The property must hold either one address with no trailing data or
309  * one address with a length. This is only tested on 32-bit machines.
310  *
311  * @param blob	FDT blob
312  * @param node	node to examine
313  * @param prop_name	name of property to find
314  * @return address, if found, or FDT_ADDR_T_NONE if not
315  */
316 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
317 		const char *prop_name);
318 
319 /**
320  * Look up an address property in a node and return it as an address.
321  * The property must hold one address with a length. This is only tested
322  * on 32-bit machines.
323  *
324  * @param blob	FDT blob
325  * @param node	node to examine
326  * @param prop_name	name of property to find
327  * @return address, if found, or FDT_ADDR_T_NONE if not
328  */
329 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
330 		const char *prop_name, fdt_size_t *sizep);
331 
332 /**
333  * Look at an address property in a node and return the pci address which
334  * corresponds to the given type in the form of fdt_pci_addr.
335  * The property must hold one fdt_pci_addr with a lengh.
336  *
337  * @param blob		FDT blob
338  * @param node		node to examine
339  * @param type		pci address type (FDT_PCI_SPACE_xxx)
340  * @param prop_name	name of property to find
341  * @param addr		returns pci address in the form of fdt_pci_addr
342  * @return 0 if ok, -ENOENT if the property did not exist, -EINVAL if the
343  *		format of the property was invalid, -ENXIO if the requested
344  *		address type was not found
345  */
346 int fdtdec_get_pci_addr(const void *blob, int node, enum fdt_pci_space type,
347 		const char *prop_name, struct fdt_pci_addr *addr);
348 
349 /**
350  * Look at the compatible property of a device node that represents a PCI
351  * device and extract pci vendor id and device id from it.
352  *
353  * @param blob		FDT blob
354  * @param node		node to examine
355  * @param vendor	vendor id of the pci device
356  * @param device	device id of the pci device
357  * @return 0 if ok, negative on error
358  */
359 int fdtdec_get_pci_vendev(const void *blob, int node,
360 		u16 *vendor, u16 *device);
361 
362 /**
363  * Look at the pci address of a device node that represents a PCI device
364  * and parse the bus, device and function number from it. For some cases
365  * like the bus number encoded in reg property is not correct after pci
366  * enumeration, this function looks through the node's compatible strings
367  * to get these numbers extracted instead.
368  *
369  * @param blob		FDT blob
370  * @param node		node to examine
371  * @param addr		pci address in the form of fdt_pci_addr
372  * @param bdf		returns bus, device, function triplet
373  * @return 0 if ok, negative on error
374  */
375 int fdtdec_get_pci_bdf(const void *blob, int node,
376 		struct fdt_pci_addr *addr, pci_dev_t *bdf);
377 
378 /**
379  * Look at the pci address of a device node that represents a PCI device
380  * and return base address of the pci device's registers.
381  *
382  * @param blob		FDT blob
383  * @param node		node to examine
384  * @param addr		pci address in the form of fdt_pci_addr
385  * @param bar		returns base address of the pci device's registers
386  * @return 0 if ok, negative on error
387  */
388 int fdtdec_get_pci_bar32(const void *blob, int node,
389 		struct fdt_pci_addr *addr, u32 *bar);
390 
391 /**
392  * Look up a 32-bit integer property in a node and return it. The property
393  * must have at least 4 bytes of data. The value of the first cell is
394  * returned.
395  *
396  * @param blob	FDT blob
397  * @param node	node to examine
398  * @param prop_name	name of property to find
399  * @param default_val	default value to return if the property is not found
400  * @return integer value, if found, or default_val if not
401  */
402 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
403 		s32 default_val);
404 
405 /**
406  * Get a variable-sized number from a property
407  *
408  * This reads a number from one or more cells.
409  *
410  * @param ptr	Pointer to property
411  * @param cells	Number of cells containing the number
412  * @return the value in the cells
413  */
414 u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells);
415 
416 /**
417  * Look up a 64-bit integer property in a node and return it. The property
418  * must have at least 8 bytes of data (2 cells). The first two cells are
419  * concatenated to form a 8 bytes value, where the first cell is top half and
420  * the second cell is bottom half.
421  *
422  * @param blob	FDT blob
423  * @param node	node to examine
424  * @param prop_name	name of property to find
425  * @param default_val	default value to return if the property is not found
426  * @return integer value, if found, or default_val if not
427  */
428 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
429 		uint64_t default_val);
430 
431 /**
432  * Checks whether a node is enabled.
433  * This looks for a 'status' property. If this exists, then returns 1 if
434  * the status is 'ok' and 0 otherwise. If there is no status property,
435  * it returns 1 on the assumption that anything mentioned should be enabled
436  * by default.
437  *
438  * @param blob	FDT blob
439  * @param node	node to examine
440  * @return integer value 0 (not enabled) or 1 (enabled)
441  */
442 int fdtdec_get_is_enabled(const void *blob, int node);
443 
444 /**
445  * Make sure we have a valid fdt available to control U-Boot.
446  *
447  * If not, a message is printed to the console if the console is ready.
448  *
449  * @return 0 if all ok, -1 if not
450  */
451 int fdtdec_prepare_fdt(void);
452 
453 /**
454  * Checks that we have a valid fdt available to control U-Boot.
455 
456  * However, if not then for the moment nothing is done, since this function
457  * is called too early to panic().
458  *
459  * @returns 0
460  */
461 int fdtdec_check_fdt(void);
462 
463 /**
464  * Find the nodes for a peripheral and return a list of them in the correct
465  * order. This is used to enumerate all the peripherals of a certain type.
466  *
467  * To use this, optionally set up a /aliases node with alias properties for
468  * a peripheral. For example, for usb you could have:
469  *
470  * aliases {
471  *		usb0 = "/ehci@c5008000";
472  *		usb1 = "/ehci@c5000000";
473  * };
474  *
475  * Pass "usb" as the name to this function and will return a list of two
476  * nodes offsets: /ehci@c5008000 and ehci@c5000000.
477  *
478  * All nodes returned will match the compatible ID, as it is assumed that
479  * all peripherals use the same driver.
480  *
481  * If no alias node is found, then the node list will be returned in the
482  * order found in the fdt. If the aliases mention a node which doesn't
483  * exist, then this will be ignored. If nodes are found with no aliases,
484  * they will be added in any order.
485  *
486  * If there is a gap in the aliases, then this function return a 0 node at
487  * that position. The return value will also count these gaps.
488  *
489  * This function checks node properties and will not return nodes which are
490  * marked disabled (status = "disabled").
491  *
492  * @param blob		FDT blob to use
493  * @param name		Root name of alias to search for
494  * @param id		Compatible ID to look for
495  * @param node_list	Place to put list of found nodes
496  * @param maxcount	Maximum number of nodes to find
497  * @return number of nodes found on success, FTD_ERR_... on error
498  */
499 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
500 			enum fdt_compat_id id, int *node_list, int maxcount);
501 
502 /*
503  * This function is similar to fdtdec_find_aliases_for_id() except that it
504  * adds to the node_list that is passed in. Any 0 elements are considered
505  * available for allocation - others are considered already used and are
506  * skipped.
507  *
508  * You can use this by calling fdtdec_find_aliases_for_id() with an
509  * uninitialised array, then setting the elements that are returned to -1,
510  * say, then calling this function, perhaps with a different compat id.
511  * Any elements you get back that are >0 are new nodes added by the call
512  * to this function.
513  *
514  * Note that if you have some nodes with aliases and some without, you are
515  * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
516  * one compat_id may fill in positions for which you have aliases defined
517  * for another compat_id. When you later call *this* function with the second
518  * compat_id, the alias positions may already be used. A debug warning may
519  * be generated in this case, but it is safest to define aliases for all
520  * nodes when you care about the ordering.
521  */
522 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
523 			enum fdt_compat_id id, int *node_list, int maxcount);
524 
525 /**
526  * Get the alias sequence number of a node
527  *
528  * This works out whether a node is pointed to by an alias, and if so, the
529  * sequence number of that alias. Aliases are of the form <base><num> where
530  * <num> is the sequence number. For example spi2 would be sequence number
531  * 2.
532  *
533  * @param blob		Device tree blob (if NULL, then error is returned)
534  * @param base		Base name for alias (before the underscore)
535  * @param node		Node to look up
536  * @param seqp		This is set to the sequence number if one is found,
537  *			but otherwise the value is left alone
538  * @return 0 if a sequence was found, -ve if not
539  */
540 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
541 			 int *seqp);
542 
543 /**
544  * Get the offset of the given chosen node
545  *
546  * This looks up a property in /chosen containing the path to another node,
547  * then finds the offset of that node.
548  *
549  * @param blob		Device tree blob (if NULL, then error is returned)
550  * @param name		Property name, e.g. "stdout-path"
551  * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
552  */
553 int fdtdec_get_chosen_node(const void *blob, const char *name);
554 
555 /*
556  * Get the name for a compatible ID
557  *
558  * @param id		Compatible ID to look for
559  * @return compatible string for that id
560  */
561 const char *fdtdec_get_compatible(enum fdt_compat_id id);
562 
563 /* Look up a phandle and follow it to its node. Then return the offset
564  * of that node.
565  *
566  * @param blob		FDT blob
567  * @param node		node to examine
568  * @param prop_name	name of property to find
569  * @return node offset if found, -ve error code on error
570  */
571 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
572 
573 /**
574  * Look up a property in a node and return its contents in an integer
575  * array of given length. The property must have at least enough data for
576  * the array (4*count bytes). It may have more, but this will be ignored.
577  *
578  * @param blob		FDT blob
579  * @param node		node to examine
580  * @param prop_name	name of property to find
581  * @param array		array to fill with data
582  * @param count		number of array elements
583  * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
584  *		or -FDT_ERR_BADLAYOUT if not enough data
585  */
586 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
587 		u32 *array, int count);
588 
589 /**
590  * Look up a property in a node and return its contents in an integer
591  * array of given length. The property must exist but may have less data that
592  * expected (4*count bytes). It may have more, but this will be ignored.
593  *
594  * @param blob		FDT blob
595  * @param node		node to examine
596  * @param prop_name	name of property to find
597  * @param array		array to fill with data
598  * @param count		number of array elements
599  * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
600  *		property is not found
601  */
602 int fdtdec_get_int_array_count(const void *blob, int node,
603 			       const char *prop_name, u32 *array, int count);
604 
605 /**
606  * Look up a property in a node and return a pointer to its contents as a
607  * unsigned int array of given length. The property must have at least enough
608  * data for the array ('count' cells). It may have more, but this will be
609  * ignored. The data is not copied.
610  *
611  * Note that you must access elements of the array with fdt32_to_cpu(),
612  * since the elements will be big endian even on a little endian machine.
613  *
614  * @param blob		FDT blob
615  * @param node		node to examine
616  * @param prop_name	name of property to find
617  * @param count		number of array elements
618  * @return pointer to array if found, or NULL if the property is not
619  *		found or there is not enough data
620  */
621 const u32 *fdtdec_locate_array(const void *blob, int node,
622 			       const char *prop_name, int count);
623 
624 /**
625  * Look up a boolean property in a node and return it.
626  *
627  * A boolean properly is true if present in the device tree and false if not
628  * present, regardless of its value.
629  *
630  * @param blob	FDT blob
631  * @param node	node to examine
632  * @param prop_name	name of property to find
633  * @return 1 if the properly is present; 0 if it isn't present
634  */
635 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
636 
637 /**
638  * Look in the FDT for a config item with the given name and return its value
639  * as a 32-bit integer. The property must have at least 4 bytes of data. The
640  * value of the first cell is returned.
641  *
642  * @param blob		FDT blob to use
643  * @param prop_name	Node property name
644  * @param default_val	default value to return if the property is not found
645  * @return integer value, if found, or default_val if not
646  */
647 int fdtdec_get_config_int(const void *blob, const char *prop_name,
648 		int default_val);
649 
650 /**
651  * Look in the FDT for a config item with the given name
652  * and return whether it exists.
653  *
654  * @param blob		FDT blob
655  * @param prop_name	property name to look up
656  * @return 1, if it exists, or 0 if not
657  */
658 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
659 
660 /**
661  * Look in the FDT for a config item with the given name and return its value
662  * as a string.
663  *
664  * @param blob          FDT blob
665  * @param prop_name     property name to look up
666  * @returns property string, NULL on error.
667  */
668 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
669 
670 /*
671  * Look up a property in a node and return its contents in a byte
672  * array of given length. The property must have at least enough data for
673  * the array (count bytes). It may have more, but this will be ignored.
674  *
675  * @param blob		FDT blob
676  * @param node		node to examine
677  * @param prop_name	name of property to find
678  * @param array		array to fill with data
679  * @param count		number of array elements
680  * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
681  *		or -FDT_ERR_BADLAYOUT if not enough data
682  */
683 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
684 		u8 *array, int count);
685 
686 /**
687  * Look up a property in a node and return a pointer to its contents as a
688  * byte array of given length. The property must have at least enough data
689  * for the array (count bytes). It may have more, but this will be ignored.
690  * The data is not copied.
691  *
692  * @param blob		FDT blob
693  * @param node		node to examine
694  * @param prop_name	name of property to find
695  * @param count		number of array elements
696  * @return pointer to byte array if found, or NULL if the property is not
697  *		found or there is not enough data
698  */
699 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
700 			     const char *prop_name, int count);
701 
702 /**
703  * Look up a property in a node which contains a memory region address and
704  * size. Then return a pointer to this address.
705  *
706  * The property must hold one address with a length. This is only tested on
707  * 32-bit machines.
708  *
709  * @param blob		FDT blob
710  * @param node		node to examine
711  * @param prop_name	name of property to find
712  * @param basep		Returns base address of region
713  * @param size		Returns size of region
714  * @return 0 if ok, -1 on error (property not found)
715  */
716 int fdtdec_decode_region(const void *blob, int node, const char *prop_name,
717 			 fdt_addr_t *basep, fdt_size_t *sizep);
718 
719 enum fmap_compress_t {
720 	FMAP_COMPRESS_NONE,
721 	FMAP_COMPRESS_LZO,
722 };
723 
724 enum fmap_hash_t {
725 	FMAP_HASH_NONE,
726 	FMAP_HASH_SHA1,
727 	FMAP_HASH_SHA256,
728 };
729 
730 /* A flash map entry, containing an offset and length */
731 struct fmap_entry {
732 	uint32_t offset;
733 	uint32_t length;
734 	uint32_t used;			/* Number of bytes used in region */
735 	enum fmap_compress_t compress_algo;	/* Compression type */
736 	enum fmap_hash_t hash_algo;		/* Hash algorithm */
737 	const uint8_t *hash;			/* Hash value */
738 	int hash_size;				/* Hash size */
739 };
740 
741 /**
742  * Read a flash entry from the fdt
743  *
744  * @param blob		FDT blob
745  * @param node		Offset of node to read
746  * @param name		Name of node being read
747  * @param entry		Place to put offset and size of this node
748  * @return 0 if ok, -ve on error
749  */
750 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
751 			   struct fmap_entry *entry);
752 
753 /**
754  * Obtain an indexed resource from a device property.
755  *
756  * @param fdt		FDT blob
757  * @param node		node to examine
758  * @param property	name of the property to parse
759  * @param index		index of the resource to retrieve
760  * @param res		returns the resource
761  * @return 0 if ok, negative on error
762  */
763 int fdt_get_resource(const void *fdt, int node, const char *property,
764 		     unsigned int index, struct fdt_resource *res);
765 
766 /**
767  * Obtain a named resource from a device property.
768  *
769  * Look up the index of the name in a list of strings and return the resource
770  * at that index.
771  *
772  * @param fdt		FDT blob
773  * @param node		node to examine
774  * @param property	name of the property to parse
775  * @param prop_names	name of the property containing the list of names
776  * @param name		the name of the entry to look up
777  * @param res		returns the resource
778  */
779 int fdt_get_named_resource(const void *fdt, int node, const char *property,
780 			   const char *prop_names, const char *name,
781 			   struct fdt_resource *res);
782 
783 /**
784  * Decode a named region within a memory bank of a given type.
785  *
786  * This function handles selection of a memory region. The region is
787  * specified as an offset/size within a particular type of memory.
788  *
789  * The properties used are:
790  *
791  *	<mem_type>-memory<suffix> for the name of the memory bank
792  *	<mem_type>-offset<suffix> for the offset in that bank
793  *
794  * The property value must have an offset and a size. The function checks
795  * that the region is entirely within the memory bank.5
796  *
797  * @param blob		FDT blob
798  * @param node		Node containing the properties (-1 for /config)
799  * @param mem_type	Type of memory to use, which is a name, such as
800  *			"u-boot" or "kernel".
801  * @param suffix	String to append to the memory/offset
802  *			property names
803  * @param basep		Returns base of region
804  * @param sizep		Returns size of region
805  * @return 0 if OK, -ive on error
806  */
807 int fdtdec_decode_memory_region(const void *blob, int node,
808 				const char *mem_type, const char *suffix,
809 				fdt_addr_t *basep, fdt_size_t *sizep);
810 
811 /* Display timings from linux include/video/display_timing.h */
812 enum display_flags {
813 	DISPLAY_FLAGS_HSYNC_LOW		= 1 << 0,
814 	DISPLAY_FLAGS_HSYNC_HIGH	= 1 << 1,
815 	DISPLAY_FLAGS_VSYNC_LOW		= 1 << 2,
816 	DISPLAY_FLAGS_VSYNC_HIGH	= 1 << 3,
817 
818 	/* data enable flag */
819 	DISPLAY_FLAGS_DE_LOW		= 1 << 4,
820 	DISPLAY_FLAGS_DE_HIGH		= 1 << 5,
821 	/* drive data on pos. edge */
822 	DISPLAY_FLAGS_PIXDATA_POSEDGE	= 1 << 6,
823 	/* drive data on neg. edge */
824 	DISPLAY_FLAGS_PIXDATA_NEGEDGE	= 1 << 7,
825 	DISPLAY_FLAGS_INTERLACED	= 1 << 8,
826 	DISPLAY_FLAGS_DOUBLESCAN	= 1 << 9,
827 	DISPLAY_FLAGS_DOUBLECLK		= 1 << 10,
828 };
829 
830 /*
831  * A single signal can be specified via a range of minimal and maximal values
832  * with a typical value, that lies somewhere inbetween.
833  */
834 struct timing_entry {
835 	u32 min;
836 	u32 typ;
837 	u32 max;
838 };
839 
840 /*
841  * Single "mode" entry. This describes one set of signal timings a display can
842  * have in one setting. This struct can later be converted to struct videomode
843  * (see include/video/videomode.h). As each timing_entry can be defined as a
844  * range, one struct display_timing may become multiple struct videomodes.
845  *
846  * Example: hsync active high, vsync active low
847  *
848  *				    Active Video
849  * Video  ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
850  *	  |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
851  *	  |	     |	 porch  |		     |	 porch	 |
852  *
853  * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯
854  *
855  * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________
856  */
857 struct display_timing {
858 	struct timing_entry pixelclock;
859 
860 	struct timing_entry hactive;		/* hor. active video */
861 	struct timing_entry hfront_porch;	/* hor. front porch */
862 	struct timing_entry hback_porch;	/* hor. back porch */
863 	struct timing_entry hsync_len;		/* hor. sync len */
864 
865 	struct timing_entry vactive;		/* ver. active video */
866 	struct timing_entry vfront_porch;	/* ver. front porch */
867 	struct timing_entry vback_porch;	/* ver. back porch */
868 	struct timing_entry vsync_len;		/* ver. sync len */
869 
870 	enum display_flags flags;		/* display flags */
871 };
872 
873 /**
874  * fdtdec_decode_display_timing() - decode display timings
875  *
876  * Decode display timings from the supplied 'display-timings' node.
877  * See doc/device-tree-bindings/video/display-timing.txt for binding
878  * information.
879  *
880  * @param blob		FDT blob
881  * @param node		'display-timing' node containing the timing subnodes
882  * @param index		Index number to read (0=first timing subnode)
883  * @param config	Place to put timings
884  * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
885  */
886 int fdtdec_decode_display_timing(const void *blob, int node, int index,
887 				 struct display_timing *config);
888 /**
889  * Set up the device tree ready for use
890  */
891 int fdtdec_setup(void);
892 
893 #endif
894