1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Copyright (c) 2011 The Chromium OS Authors.
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.
17 #include <linux/libfdt.h>
21 * A typedef for a physical address. Note that fdt data is always big
22 * endian even on a litle endian machine.
24 typedef phys_addr_t fdt_addr_t;
25 typedef phys_size_t fdt_size_t;
27 #define FDT_ADDR_T_NONE (-1U)
28 #define FDT_SIZE_T_NONE (-1U)
30 #ifdef CONFIG_PHYS_64BIT
31 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
32 #define fdt_size_to_cpu(reg) be64_to_cpu(reg)
33 #define cpu_to_fdt_addr(reg) cpu_to_be64(reg)
34 #define cpu_to_fdt_size(reg) cpu_to_be64(reg)
35 typedef fdt64_t fdt_val_t;
37 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
38 #define fdt_size_to_cpu(reg) be32_to_cpu(reg)
39 #define cpu_to_fdt_addr(reg) cpu_to_be32(reg)
40 #define cpu_to_fdt_size(reg) cpu_to_be32(reg)
41 typedef fdt32_t fdt_val_t;
44 /* Information obtained about memory from the FDT */
53 * enum fdt_source_t - indicates where the devicetree came from
55 * These are listed in approximate order of desirability after FDTSRC_NONE
57 * @FDTSRC_SEPARATE: Appended to U-Boot. This is the normal approach if U-Boot
58 * is the only firmware being booted
59 * @FDTSRC_FIT: Found in a multi-dtb FIT. This should be used when U-Boot must
60 * select a devicetree from many options
61 * @FDTSRC_BOARD: Located by custom board code. This should only be used when
62 * the prior stage does not support FDTSRC_PASSAGE
63 * @FDTSRC_EMBED: Embedded into U-Boot executable. This should onyl be used when
64 * U-Boot is packaged as an ELF file, e.g. for debugging purposes
65 * @FDTSRC_ENV: Provided by the fdtcontroladdr environment variable. This should
66 * be used for debugging/development only
67 * @FDTSRC_NONE: No devicetree at all
78 * Information about a resource. start is the first address of the resource
79 * and end is the last address (inclusive). The length of the resource will
80 * be equal to: end - start + 1.
88 FDT_PCI_SPACE_CONFIG = 0,
89 FDT_PCI_SPACE_IO = 0x01000000,
90 FDT_PCI_SPACE_MEM32 = 0x02000000,
91 FDT_PCI_SPACE_MEM64 = 0x03000000,
92 FDT_PCI_SPACE_MEM32_PREF = 0x42000000,
93 FDT_PCI_SPACE_MEM64_PREF = 0x43000000,
96 #define FDT_PCI_ADDR_CELLS 3
97 #define FDT_PCI_SIZE_CELLS 2
98 #define FDT_PCI_REG_SIZE \
99 ((FDT_PCI_ADDR_CELLS + FDT_PCI_SIZE_CELLS) * sizeof(u32))
102 * The Open Firmware spec defines PCI physical address as follows:
104 * bits# 31 .... 24 23 .... 16 15 .... 08 07 .... 00
106 * phys.hi cell: npt000ss bbbbbbbb dddddfff rrrrrrrr
107 * phys.mid cell: hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh
108 * phys.lo cell: llllllll llllllll llllllll llllllll
112 * n: is 0 if the address is relocatable, 1 otherwise
113 * p: is 1 if addressable region is prefetchable, 0 otherwise
114 * t: is 1 if the address is aliased (for non-relocatable I/O) below 1MB
115 * (for Memory), or below 64KB (for relocatable I/O)
116 * ss: is the space code, denoting the address space
117 * bbbbbbbb: is the 8-bit Bus Number
118 * ddddd: is the 5-bit Device Number
119 * fff: is the 3-bit Function Number
120 * rrrrrrrr: is the 8-bit Register Number
121 * hhhhhhhh: is a 32-bit unsigned number
122 * llllllll: is a 32-bit unsigned number
124 struct fdt_pci_addr {
130 extern u8 __dtb_dt_begin[]; /* embedded device tree blob */
131 extern u8 __dtb_dt_spl_begin[]; /* embedded device tree blob for SPL/TPL */
133 /* Get a pointer to the embedded devicetree, if there is one, else NULL */
134 static inline u8 *dtb_dt_embedded(void)
136 #ifdef CONFIG_OF_EMBED
137 # ifdef CONFIG_SPL_BUILD
138 return __dtb_dt_spl_begin;
140 return __dtb_dt_begin;
148 * Compute the size of a resource.
150 * @param res the resource to operate on
151 * @return the size of the resource
153 static inline fdt_size_t fdt_resource_size(const struct fdt_resource *res)
155 return res->end - res->start + 1;
159 * Compat types that we know about and for which we might have drivers.
160 * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
165 COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */
166 COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
167 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */
168 COMPAT_NVIDIA_TEGRA124_XUSB_PADCTL,
169 /* Tegra124 XUSB pad controller */
170 COMPAT_NVIDIA_TEGRA210_XUSB_PADCTL,
171 /* Tegra210 XUSB pad controller */
172 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */
173 COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
174 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */
175 COMPAT_SAMSUNG_EXYNOS_MIPI_DSI, /* Exynos mipi dsi */
176 COMPAT_SAMSUNG_EXYNOS_DWMMC, /* Exynos DWMMC controller */
177 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */
178 COMPAT_SAMSUNG_EXYNOS_SYSMMU, /* Exynos sysmmu */
179 COMPAT_INTEL_MICROCODE, /* Intel microcode update */
180 COMPAT_INTEL_QRK_MRC, /* Intel Quark MRC */
181 COMPAT_ALTERA_SOCFPGA_DWMAC, /* SoCFPGA Ethernet controller */
182 COMPAT_ALTERA_SOCFPGA_DWMMC, /* SoCFPGA DWMMC controller */
183 COMPAT_ALTERA_SOCFPGA_DWC2USB, /* SoCFPGA DWC2 USB controller */
184 COMPAT_INTEL_BAYTRAIL_FSP, /* Intel Bay Trail FSP */
185 COMPAT_INTEL_BAYTRAIL_FSP_MDP, /* Intel FSP memory-down params */
186 COMPAT_INTEL_IVYBRIDGE_FSP, /* Intel Ivy Bridge FSP */
187 COMPAT_SUNXI_NAND, /* SUNXI NAND controller */
188 COMPAT_ALTERA_SOCFPGA_CLK, /* SoCFPGA Clock initialization */
189 COMPAT_ALTERA_SOCFPGA_PINCTRL_SINGLE, /* SoCFPGA pinctrl-single */
190 COMPAT_ALTERA_SOCFPGA_H2F_BRG, /* SoCFPGA hps2fpga bridge */
191 COMPAT_ALTERA_SOCFPGA_LWH2F_BRG, /* SoCFPGA lwhps2fpga bridge */
192 COMPAT_ALTERA_SOCFPGA_F2H_BRG, /* SoCFPGA fpga2hps bridge */
193 COMPAT_ALTERA_SOCFPGA_F2SDR0, /* SoCFPGA fpga2SDRAM0 bridge */
194 COMPAT_ALTERA_SOCFPGA_F2SDR1, /* SoCFPGA fpga2SDRAM1 bridge */
195 COMPAT_ALTERA_SOCFPGA_F2SDR2, /* SoCFPGA fpga2SDRAM2 bridge */
196 COMPAT_ALTERA_SOCFPGA_FPGA0, /* SOCFPGA FPGA manager */
197 COMPAT_ALTERA_SOCFPGA_NOC, /* SOCFPGA Arria 10 NOC */
198 COMPAT_ALTERA_SOCFPGA_CLK_INIT, /* SOCFPGA Arria 10 clk init */
203 #define MAX_PHANDLE_ARGS 16
204 struct fdtdec_phandle_args {
207 uint32_t args[MAX_PHANDLE_ARGS];
211 * fdtdec_parse_phandle_with_args() - Find a node pointed by phandle in a list
213 * This function is useful to parse lists of phandles and their arguments.
226 * list = <&phandle1 1 2 &phandle2 3>;
229 * To get a device_node of the `node2' node you may call this:
230 * fdtdec_parse_phandle_with_args(blob, node3, "list", "#list-cells", 0, 1,
233 * (This function is a modified version of __of_parse_phandle_with_args() from
236 * @blob: Pointer to device tree
237 * @src_node: Offset of device tree node containing a list
238 * @list_name: property name that contains a list
239 * @cells_name: property name that specifies the phandles' arguments count,
240 * or NULL to use @cells_count
241 * @cells_count: Cell count to use if @cells_name is NULL
242 * @index: index of a phandle to parse out
243 * @out_args: optional pointer to output arguments structure (will be filled)
244 * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
245 * @list_name does not exist, a phandle was not found, @cells_name
246 * could not be found, the arguments were truncated or there were too
250 int fdtdec_parse_phandle_with_args(const void *blob, int src_node,
251 const char *list_name,
252 const char *cells_name,
253 int cell_count, int index,
254 struct fdtdec_phandle_args *out_args);
257 * Find the next numbered alias for a peripheral. This is used to enumerate
258 * all the peripherals of a certain type.
260 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
261 * this function will return a pointer to the node the alias points to, and
262 * then update *upto to 1. Next time you call this function, the next node
265 * All nodes returned will match the compatible ID, as it is assumed that
266 * all peripherals use the same driver.
268 * @param blob FDT blob to use
269 * @param name Root name of alias to search for
270 * @param id Compatible ID to look for
271 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
273 int fdtdec_next_alias(const void *blob, const char *name,
274 enum fdt_compat_id id, int *upto);
277 * Find the compatible ID for a given node.
279 * Generally each node has at least one compatible string attached to it.
280 * This function looks through our list of known compatible strings and
281 * returns the corresponding ID which matches the compatible string.
283 * @param blob FDT blob to use
284 * @param node Node containing compatible string to find
285 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
287 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
290 * Find the next compatible node for a peripheral.
292 * Do the first call with node = 0. This function will return a pointer to
293 * the next compatible node. Next time you call this function, pass the
294 * value returned, and the next node will be provided.
296 * @param blob FDT blob to use
297 * @param node Start node for search
298 * @param id Compatible ID to look for (enum fdt_compat_id)
299 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
301 int fdtdec_next_compatible(const void *blob, int node,
302 enum fdt_compat_id id);
305 * Find the next compatible subnode for a peripheral.
307 * Do the first call with node set to the parent and depth = 0. This
308 * function will return the offset of the next compatible node. Next time
309 * you call this function, pass the node value returned last time, with
310 * depth unchanged, and the next node will be provided.
312 * @param blob FDT blob to use
313 * @param node Start node for search
314 * @param id Compatible ID to look for (enum fdt_compat_id)
315 * @param depthp Current depth (set to 0 before first call)
316 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
318 int fdtdec_next_compatible_subnode(const void *blob, int node,
319 enum fdt_compat_id id, int *depthp);
322 * Look up an address property in a node and return the parsed address, and
323 * optionally the parsed size.
325 * This variant assumes a known and fixed number of cells are used to
326 * represent the address and size.
328 * You probably don't want to use this function directly except to parse
329 * non-standard properties, and never to parse the "reg" property. Instead,
330 * use one of the "auto" variants below, which automatically honor the
331 * #address-cells and #size-cells properties in the parent node.
333 * @param blob FDT blob
334 * @param node node to examine
335 * @param prop_name name of property to find
336 * @param index which address to retrieve from a list of addresses. Often 0.
337 * @param na the number of cells used to represent an address
338 * @param ns the number of cells used to represent a size
339 * @param sizep a pointer to store the size into. Use NULL if not required
340 * @param translate Indicates whether to translate the returned value
341 * using the parent node's ranges property.
342 * @return address, if found, or FDT_ADDR_T_NONE if not
344 fdt_addr_t fdtdec_get_addr_size_fixed(const void *blob, int node,
345 const char *prop_name, int index, int na, int ns,
346 fdt_size_t *sizep, bool translate);
349 * Look up an address property in a node and return the parsed address, and
350 * optionally the parsed size.
352 * This variant automatically determines the number of cells used to represent
353 * the address and size by parsing the provided parent node's #address-cells
354 * and #size-cells properties.
356 * @param blob FDT blob
357 * @param parent parent node of @node
358 * @param node node to examine
359 * @param prop_name name of property to find
360 * @param index which address to retrieve from a list of addresses. Often 0.
361 * @param sizep a pointer to store the size into. Use NULL if not required
362 * @param translate Indicates whether to translate the returned value
363 * using the parent node's ranges property.
364 * @return address, if found, or FDT_ADDR_T_NONE if not
366 fdt_addr_t fdtdec_get_addr_size_auto_parent(const void *blob, int parent,
367 int node, const char *prop_name, int index, fdt_size_t *sizep,
371 * Look up an address property in a node and return the parsed address, and
372 * optionally the parsed size.
374 * This variant automatically determines the number of cells used to represent
375 * the address and size by parsing the parent node's #address-cells
376 * and #size-cells properties. The parent node is automatically found.
378 * The automatic parent lookup implemented by this function is slow.
379 * Consequently, fdtdec_get_addr_size_auto_parent() should be used where
382 * @param blob FDT blob
383 * @param parent parent node of @node
384 * @param node node to examine
385 * @param prop_name name of property to find
386 * @param index which address to retrieve from a list of addresses. Often 0.
387 * @param sizep a pointer to store the size into. Use NULL if not required
388 * @param translate Indicates whether to translate the returned value
389 * using the parent node's ranges property.
390 * @return address, if found, or FDT_ADDR_T_NONE if not
392 fdt_addr_t fdtdec_get_addr_size_auto_noparent(const void *blob, int node,
393 const char *prop_name, int index, fdt_size_t *sizep,
397 * Look up an address property in a node and return the parsed address.
399 * This variant hard-codes the number of cells used to represent the address
400 * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
401 * always returns the first address value in the property (index 0).
403 * Use of this function is not recommended due to the hard-coding of cell
404 * counts. There is no programmatic validation that these hard-coded values
405 * actually match the device tree content in any way at all. This assumption
406 * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
407 * set in the U-Boot build and exercising strict control over DT content to
408 * ensure use of matching #address-cells/#size-cells properties. However, this
409 * approach is error-prone; those familiar with DT will not expect the
410 * assumption to exist, and could easily invalidate it. If the assumption is
411 * invalidated, this function will not report the issue, and debugging will
412 * be required. Instead, use fdtdec_get_addr_size_auto_parent().
414 * @param blob FDT blob
415 * @param node node to examine
416 * @param prop_name name of property to find
417 * @return address, if found, or FDT_ADDR_T_NONE if not
419 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
420 const char *prop_name);
423 * Look up an address property in a node and return the parsed address, and
424 * optionally the parsed size.
426 * This variant hard-codes the number of cells used to represent the address
427 * and size based on sizeof(fdt_addr_t) and sizeof(fdt_size_t). It also
428 * always returns the first address value in the property (index 0).
430 * Use of this function is not recommended due to the hard-coding of cell
431 * counts. There is no programmatic validation that these hard-coded values
432 * actually match the device tree content in any way at all. This assumption
433 * can be satisfied by manually ensuring CONFIG_PHYS_64BIT is appropriately
434 * set in the U-Boot build and exercising strict control over DT content to
435 * ensure use of matching #address-cells/#size-cells properties. However, this
436 * approach is error-prone; those familiar with DT will not expect the
437 * assumption to exist, and could easily invalidate it. If the assumption is
438 * invalidated, this function will not report the issue, and debugging will
439 * be required. Instead, use fdtdec_get_addr_size_auto_parent().
441 * @param blob FDT blob
442 * @param node node to examine
443 * @param prop_name name of property to find
444 * @param sizep a pointer to store the size into. Use NULL if not required
445 * @return address, if found, or FDT_ADDR_T_NONE if not
447 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
448 const char *prop_name, fdt_size_t *sizep);
451 * Look at the compatible property of a device node that represents a PCI
452 * device and extract pci vendor id and device id from it.
454 * @param blob FDT blob
455 * @param node node to examine
456 * @param vendor vendor id of the pci device
457 * @param device device id of the pci device
458 * @return 0 if ok, negative on error
460 int fdtdec_get_pci_vendev(const void *blob, int node,
461 u16 *vendor, u16 *device);
464 * Look at the pci address of a device node that represents a PCI device
465 * and return base address of the pci device's registers.
467 * @param dev device to examine
468 * @param addr pci address in the form of fdt_pci_addr
469 * @param bar returns base address of the pci device's registers
470 * @return 0 if ok, negative on error
472 int fdtdec_get_pci_bar32(const struct udevice *dev, struct fdt_pci_addr *addr,
476 * Look at the bus range property of a device node and return the pci bus
477 * range for this node.
478 * The property must hold one fdt_pci_addr with a length.
479 * @param blob FDT blob
480 * @param node node to examine
481 * @param res the resource structure to return the bus range
482 * @return 0 if ok, negative on error
485 int fdtdec_get_pci_bus_range(const void *blob, int node,
486 struct fdt_resource *res);
489 * Look up a 32-bit integer property in a node and return it. The property
490 * must have at least 4 bytes of data. The value of the first cell is
493 * @param blob FDT blob
494 * @param node node to examine
495 * @param prop_name name of property to find
496 * @param default_val default value to return if the property is not found
497 * @return integer value, if found, or default_val if not
499 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
503 * Unsigned version of fdtdec_get_int. The property must have at least
504 * 4 bytes of data. The value of the first cell is returned.
506 * @param blob FDT blob
507 * @param node node to examine
508 * @param prop_name name of property to find
509 * @param default_val default value to return if the property is not found
510 * @return unsigned integer value, if found, or default_val if not
512 unsigned int fdtdec_get_uint(const void *blob, int node, const char *prop_name,
513 unsigned int default_val);
516 * Get a variable-sized number from a property
518 * This reads a number from one or more cells.
520 * @param ptr Pointer to property
521 * @param cells Number of cells containing the number
522 * @return the value in the cells
524 u64 fdtdec_get_number(const fdt32_t *ptr, unsigned int cells);
527 * Look up a 64-bit integer property in a node and return it. The property
528 * must have at least 8 bytes of data (2 cells). The first two cells are
529 * concatenated to form a 8 bytes value, where the first cell is top half and
530 * the second cell is bottom half.
532 * @param blob FDT blob
533 * @param node node to examine
534 * @param prop_name name of property to find
535 * @param default_val default value to return if the property is not found
536 * @return integer value, if found, or default_val if not
538 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
539 uint64_t default_val);
542 * Checks whether a node is enabled.
543 * This looks for a 'status' property. If this exists, then returns 1 if
544 * the status is 'ok' and 0 otherwise. If there is no status property,
545 * it returns 1 on the assumption that anything mentioned should be enabled
548 * @param blob FDT blob
549 * @param node node to examine
550 * @return integer value 0 (not enabled) or 1 (enabled)
552 int fdtdec_get_is_enabled(const void *blob, int node);
555 * Make sure we have a valid fdt available to control U-Boot.
557 * If not, a message is printed to the console if the console is ready.
559 * @return 0 if all ok, -1 if not
561 int fdtdec_prepare_fdt(void);
564 * Checks that we have a valid fdt available to control U-Boot.
566 * However, if not then for the moment nothing is done, since this function
567 * is called too early to panic().
571 int fdtdec_check_fdt(void);
574 * Find the nodes for a peripheral and return a list of them in the correct
575 * order. This is used to enumerate all the peripherals of a certain type.
577 * To use this, optionally set up a /aliases node with alias properties for
578 * a peripheral. For example, for usb you could have:
581 * usb0 = "/ehci@c5008000";
582 * usb1 = "/ehci@c5000000";
585 * Pass "usb" as the name to this function and will return a list of two
586 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
588 * All nodes returned will match the compatible ID, as it is assumed that
589 * all peripherals use the same driver.
591 * If no alias node is found, then the node list will be returned in the
592 * order found in the fdt. If the aliases mention a node which doesn't
593 * exist, then this will be ignored. If nodes are found with no aliases,
594 * they will be added in any order.
596 * If there is a gap in the aliases, then this function return a 0 node at
597 * that position. The return value will also count these gaps.
599 * This function checks node properties and will not return nodes which are
600 * marked disabled (status = "disabled").
602 * @param blob FDT blob to use
603 * @param name Root name of alias to search for
604 * @param id Compatible ID to look for
605 * @param node_list Place to put list of found nodes
606 * @param maxcount Maximum number of nodes to find
607 * @return number of nodes found on success, FDT_ERR_... on error
609 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
610 enum fdt_compat_id id, int *node_list, int maxcount);
613 * This function is similar to fdtdec_find_aliases_for_id() except that it
614 * adds to the node_list that is passed in. Any 0 elements are considered
615 * available for allocation - others are considered already used and are
618 * You can use this by calling fdtdec_find_aliases_for_id() with an
619 * uninitialised array, then setting the elements that are returned to -1,
620 * say, then calling this function, perhaps with a different compat id.
621 * Any elements you get back that are >0 are new nodes added by the call
624 * Note that if you have some nodes with aliases and some without, you are
625 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
626 * one compat_id may fill in positions for which you have aliases defined
627 * for another compat_id. When you later call *this* function with the second
628 * compat_id, the alias positions may already be used. A debug warning may
629 * be generated in this case, but it is safest to define aliases for all
630 * nodes when you care about the ordering.
632 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
633 enum fdt_compat_id id, int *node_list, int maxcount);
636 * Get the alias sequence number of a node
638 * This works out whether a node is pointed to by an alias, and if so, the
639 * sequence number of that alias. Aliases are of the form <base><num> where
640 * <num> is the sequence number. For example spi2 would be sequence number
643 * @param blob Device tree blob (if NULL, then error is returned)
644 * @param base Base name for alias (before the underscore)
645 * @param node Node to look up
646 * @param seqp This is set to the sequence number if one is found,
647 * but otherwise the value is left alone
648 * @return 0 if a sequence was found, -ve if not
650 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
654 * Get the highest alias number for susbystem.
656 * It parses all aliases and find out highest recorded alias for subsystem.
657 * Aliases are of the form <base><num> where <num> is the sequence number.
659 * @param blob Device tree blob (if NULL, then error is returned)
660 * @param base Base name for alias susbystem (before the number)
662 * @return 0 highest alias ID, -1 if not found
664 int fdtdec_get_alias_highest_id(const void *blob, const char *base);
667 * Get a property from the /chosen node
669 * @param blob Device tree blob (if NULL, then NULL is returned)
670 * @param name Property name to look up
671 * @return Value of property, or NULL if it does not exist
673 const char *fdtdec_get_chosen_prop(const void *blob, const char *name);
676 * Get the offset of the given /chosen node
678 * This looks up a property in /chosen containing the path to another node,
679 * then finds the offset of that node.
681 * @param blob Device tree blob (if NULL, then error is returned)
682 * @param name Property name, e.g. "stdout-path"
683 * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
685 int fdtdec_get_chosen_node(const void *blob, const char *name);
688 * Get the name for a compatible ID
690 * @param id Compatible ID to look for
691 * @return compatible string for that id
693 const char *fdtdec_get_compatible(enum fdt_compat_id id);
695 /* Look up a phandle and follow it to its node. Then return the offset
698 * @param blob FDT blob
699 * @param node node to examine
700 * @param prop_name name of property to find
701 * @return node offset if found, -ve error code on error
703 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
706 * Look up a property in a node and return its contents in an integer
707 * array of given length. The property must have at least enough data for
708 * the array (4*count bytes). It may have more, but this will be ignored.
710 * @param blob FDT blob
711 * @param node node to examine
712 * @param prop_name name of property to find
713 * @param array array to fill with data
714 * @param count number of array elements
715 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
716 * or -FDT_ERR_BADLAYOUT if not enough data
718 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
719 u32 *array, int count);
722 * Look up a property in a node and return its contents in an integer
723 * array of given length. The property must exist but may have less data that
724 * expected (4*count bytes). It may have more, but this will be ignored.
726 * @param blob FDT blob
727 * @param node node to examine
728 * @param prop_name name of property to find
729 * @param array array to fill with data
730 * @param count number of array elements
731 * @return number of array elements if ok, or -FDT_ERR_NOTFOUND if the
732 * property is not found
734 int fdtdec_get_int_array_count(const void *blob, int node,
735 const char *prop_name, u32 *array, int count);
738 * Look up a property in a node and return a pointer to its contents as a
739 * unsigned int array of given length. The property must have at least enough
740 * data for the array ('count' cells). It may have more, but this will be
741 * ignored. The data is not copied.
743 * Note that you must access elements of the array with fdt32_to_cpu(),
744 * since the elements will be big endian even on a little endian machine.
746 * @param blob FDT blob
747 * @param node node to examine
748 * @param prop_name name of property to find
749 * @param count number of array elements
750 * @return pointer to array if found, or NULL if the property is not
751 * found or there is not enough data
753 const u32 *fdtdec_locate_array(const void *blob, int node,
754 const char *prop_name, int count);
757 * Look up a boolean property in a node and return it.
759 * A boolean properly is true if present in the device tree and false if not
760 * present, regardless of its value.
762 * @param blob FDT blob
763 * @param node node to examine
764 * @param prop_name name of property to find
765 * @return 1 if the properly is present; 0 if it isn't present
767 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
770 * Count child nodes of one parent node.
772 * @param blob FDT blob
773 * @param node parent node
774 * @return number of child node; 0 if there is not child node
776 int fdtdec_get_child_count(const void *blob, int node);
779 * Look up a property in a node and return its contents in a byte
780 * array of given length. The property must have at least enough data for
781 * the array (count bytes). It may have more, but this will be ignored.
783 * @param blob FDT blob
784 * @param node node to examine
785 * @param prop_name name of property to find
786 * @param array array to fill with data
787 * @param count number of array elements
788 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
789 * or -FDT_ERR_BADLAYOUT if not enough data
791 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
792 u8 *array, int count);
795 * Look up a property in a node and return a pointer to its contents as a
796 * byte array of given length. The property must have at least enough data
797 * for the array (count bytes). It may have more, but this will be ignored.
798 * The data is not copied.
800 * @param blob FDT blob
801 * @param node node to examine
802 * @param prop_name name of property to find
803 * @param count number of array elements
804 * @return pointer to byte array if found, or NULL if the property is not
805 * found or there is not enough data
807 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
808 const char *prop_name, int count);
811 * Obtain an indexed resource from a device property.
813 * @param fdt FDT blob
814 * @param node node to examine
815 * @param property name of the property to parse
816 * @param index index of the resource to retrieve
817 * @param res returns the resource
818 * @return 0 if ok, negative on error
820 int fdt_get_resource(const void *fdt, int node, const char *property,
821 unsigned int index, struct fdt_resource *res);
824 * Obtain a named resource from a device property.
826 * Look up the index of the name in a list of strings and return the resource
829 * @param fdt FDT blob
830 * @param node node to examine
831 * @param property name of the property to parse
832 * @param prop_names name of the property containing the list of names
833 * @param name the name of the entry to look up
834 * @param res returns the resource
836 int fdt_get_named_resource(const void *fdt, int node, const char *property,
837 const char *prop_names, const char *name,
838 struct fdt_resource *res);
840 /* Display timings from linux include/video/display_timing.h */
842 DISPLAY_FLAGS_HSYNC_LOW = 1 << 0,
843 DISPLAY_FLAGS_HSYNC_HIGH = 1 << 1,
844 DISPLAY_FLAGS_VSYNC_LOW = 1 << 2,
845 DISPLAY_FLAGS_VSYNC_HIGH = 1 << 3,
847 /* data enable flag */
848 DISPLAY_FLAGS_DE_LOW = 1 << 4,
849 DISPLAY_FLAGS_DE_HIGH = 1 << 5,
850 /* drive data on pos. edge */
851 DISPLAY_FLAGS_PIXDATA_POSEDGE = 1 << 6,
852 /* drive data on neg. edge */
853 DISPLAY_FLAGS_PIXDATA_NEGEDGE = 1 << 7,
854 DISPLAY_FLAGS_INTERLACED = 1 << 8,
855 DISPLAY_FLAGS_DOUBLESCAN = 1 << 9,
856 DISPLAY_FLAGS_DOUBLECLK = 1 << 10,
860 * A single signal can be specified via a range of minimal and maximal values
861 * with a typical value, that lies somewhere inbetween.
863 struct timing_entry {
870 * Single "mode" entry. This describes one set of signal timings a display can
871 * have in one setting. This struct can later be converted to struct videomode
872 * (see include/video/videomode.h). As each timing_entry can be defined as a
873 * range, one struct display_timing may become multiple struct videomodes.
875 * Example: hsync active high, vsync active low
878 * Video ______________________XXXXXXXXXXXXXXXXXXXXXX_____________________
879 * |<- sync ->|<- back ->|<----- active ----->|<- front ->|<- sync..
880 * | | porch | | porch |
882 * HSync _|¯¯¯¯¯¯¯¯¯¯|___________________________________________|¯¯¯¯¯¯¯¯¯
884 * VSync ¯|__________|¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯|_________
886 struct display_timing {
887 struct timing_entry pixelclock;
889 struct timing_entry hactive; /* hor. active video */
890 struct timing_entry hfront_porch; /* hor. front porch */
891 struct timing_entry hback_porch; /* hor. back porch */
892 struct timing_entry hsync_len; /* hor. sync len */
894 struct timing_entry vactive; /* ver. active video */
895 struct timing_entry vfront_porch; /* ver. front porch */
896 struct timing_entry vback_porch; /* ver. back porch */
897 struct timing_entry vsync_len; /* ver. sync len */
899 enum display_flags flags; /* display flags */
900 bool hdmi_monitor; /* is hdmi monitor? */
904 * fdtdec_decode_display_timing() - decode display timings
906 * Decode display timings from the supplied 'display-timings' node.
907 * See doc/device-tree-bindings/video/display-timing.txt for binding
910 * @param blob FDT blob
911 * @param node 'display-timing' node containing the timing subnodes
912 * @param index Index number to read (0=first timing subnode)
913 * @param config Place to put timings
914 * @return 0 if OK, -FDT_ERR_NOTFOUND if not found
916 int fdtdec_decode_display_timing(const void *blob, int node, int index,
917 struct display_timing *config);
920 * fdtdec_setup_mem_size_base() - decode and setup gd->ram_size and
923 * Decode the /memory 'reg' property to determine the size and start of the
924 * first memory bank, populate the global data with the size and start of the
925 * first bank of memory.
927 * This function should be called from a boards dram_init(). This helper
928 * function allows for boards to query the device tree for DRAM size and start
929 * address instead of hard coding the value in the case where the memory size
930 * and start address cannot be detected automatically.
932 * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
935 int fdtdec_setup_mem_size_base(void);
938 * fdtdec_setup_mem_size_base_lowest() - decode and setup gd->ram_size and
939 * gd->ram_start by lowest available memory base
941 * Decode the /memory 'reg' property to determine the lowest start of the memory
942 * bank bank and populate the global data with it.
944 * This function should be called from a boards dram_init(). This helper
945 * function allows for boards to query the device tree for DRAM size and start
946 * address instead of hard coding the value in the case where the memory size
947 * and start address cannot be detected automatically.
949 * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
952 int fdtdec_setup_mem_size_base_lowest(void);
955 * fdtdec_setup_memory_banksize() - decode and populate gd->bd->bi_dram
957 * Decode the /memory 'reg' property to determine the address and size of the
958 * memory banks. Use this data to populate the global data board info with the
959 * phys address and size of memory banks.
961 * This function should be called from a boards dram_init_banksize(). This
962 * helper function allows for boards to query the device tree for memory bank
963 * information instead of hard coding the information in cases where it cannot
964 * be detected automatically.
966 * @return 0 if OK, -EINVAL if the /memory node or reg property is missing or
969 int fdtdec_setup_memory_banksize(void);
972 * fdtdec_set_ethernet_mac_address() - set MAC address for default interface
974 * Looks up the default interface via the "ethernet" alias (in the /aliases
975 * node) and stores the given MAC in its "local-mac-address" property. This
976 * is useful on platforms that store the MAC address in a custom location.
977 * Board code can call this in the late init stage to make sure that the
978 * interface device tree node has the right MAC address configured for the
979 * Ethernet uclass to pick it up.
981 * Typically the FDT passed into this function will be U-Boot's control DTB.
982 * Given that a lot of code may be holding offsets to various nodes in that
983 * tree, this code will only set the "local-mac-address" property in-place,
984 * which means that it needs to exist and have space for the 6-byte address.
985 * This ensures that the operation is non-destructive and does not invalidate
986 * offsets that other drivers may be using.
988 * @param fdt FDT blob
989 * @param mac buffer containing the MAC address to set
990 * @param size size of MAC address
991 * @return 0 on success or a negative error code on failure
993 int fdtdec_set_ethernet_mac_address(void *fdt, const u8 *mac, size_t size);
996 * fdtdec_set_phandle() - sets the phandle of a given node
998 * @param blob FDT blob
999 * @param node offset in the FDT blob of the node whose phandle is to
1001 * @param phandle phandle to set for the given node
1002 * @return 0 on success or a negative error code on failure
1004 static inline int fdtdec_set_phandle(void *blob, int node, uint32_t phandle)
1006 return fdt_setprop_u32(blob, node, "phandle", phandle);
1009 /* add "no-map" property */
1010 #define FDTDEC_RESERVED_MEMORY_NO_MAP (1 << 0)
1013 * fdtdec_add_reserved_memory() - add or find a reserved-memory node
1015 * If a reserved-memory node already exists for the given carveout, a phandle
1016 * for that node will be returned. Otherwise a new node will be created and a
1017 * phandle corresponding to it will be returned.
1019 * See Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
1020 * for details on how to use reserved memory regions.
1022 * As an example, consider the following code snippet:
1024 * struct fdt_memory fb = {
1025 * .start = 0x92cb3000,
1026 * .end = 0x934b2fff,
1030 * fdtdec_add_reserved_memory(fdt, "framebuffer", &fb, NULL, 0, &phandle,
1033 * This results in the following subnode being added to the top-level
1034 * /reserved-memory node:
1037 * #address-cells = <0x00000002>;
1038 * #size-cells = <0x00000002>;
1041 * framebuffer@92cb3000 {
1042 * reg = <0x00000000 0x92cb3000 0x00000000 0x00800000>;
1043 * phandle = <0x0000004d>;
1047 * If the top-level /reserved-memory node does not exist, it will be created.
1048 * The phandle returned from the function call can be used to reference this
1049 * reserved memory region from other nodes.
1051 * See fdtdec_set_carveout() for a more elaborate example.
1053 * @param blob FDT blob
1054 * @param basename base name of the node to create
1055 * @param carveout information about the carveout region
1056 * @param compatibles list of compatible strings for the carveout region
1057 * @param count number of compatible strings for the carveout region
1058 * @param phandlep return location for the phandle of the carveout region
1059 * can be NULL if no phandle should be added
1060 * @param flags bitmask of flags to set for the carveout region
1061 * @return 0 on success or a negative error code on failure
1063 int fdtdec_add_reserved_memory(void *blob, const char *basename,
1064 const struct fdt_memory *carveout,
1065 const char **compatibles, unsigned int count,
1066 uint32_t *phandlep, unsigned long flags);
1069 * fdtdec_get_carveout() - reads a carveout from an FDT
1071 * Reads information about a carveout region from an FDT. The carveout is a
1072 * referenced by its phandle that is read from a given property in a given
1075 * @param blob FDT blob
1076 * @param node name of a node
1077 * @param prop_name name of the property in the given node that contains
1078 * the phandle for the carveout
1079 * @param index index of the phandle for which to read the carveout
1080 * @param carveout return location for the carveout information
1081 * @param name return location for the carveout name
1082 * @param compatiblesp return location for compatible strings
1083 * @param countp return location for the number of compatible strings
1084 * @param flags return location for the flags of the carveout
1085 * @return 0 on success or a negative error code on failure
1087 int fdtdec_get_carveout(const void *blob, const char *node,
1088 const char *prop_name, unsigned int index,
1089 struct fdt_memory *carveout, const char **name,
1090 const char ***compatiblesp, unsigned int *countp,
1091 unsigned long *flags);
1094 * fdtdec_set_carveout() - sets a carveout region for a given node
1096 * Sets a carveout region for a given node. If a reserved-memory node already
1097 * exists for the carveout, the phandle for that node will be reused. If no
1098 * such node exists, a new one will be created and a phandle to it stored in
1099 * a specified property of the given node.
1101 * As an example, consider the following code snippet:
1103 * const char *node = "/host1x@50000000/dc@54240000";
1104 * struct fdt_memory fb = {
1105 * .start = 0x92cb3000,
1106 * .end = 0x934b2fff,
1109 * fdtdec_set_carveout(fdt, node, "memory-region", 0, "framebuffer", NULL,
1112 * dc@54200000 is a display controller and was set up by the bootloader to
1113 * scan out the framebuffer specified by "fb". This would cause the following
1114 * reserved memory region to be added:
1117 * #address-cells = <0x00000002>;
1118 * #size-cells = <0x00000002>;
1121 * framebuffer@92cb3000 {
1122 * reg = <0x00000000 0x92cb3000 0x00000000 0x00800000>;
1123 * phandle = <0x0000004d>;
1127 * A "memory-region" property will also be added to the node referenced by the
1135 * memory-region = <0x0000004d>;
1142 * @param blob FDT blob
1143 * @param node name of the node to add the carveout to
1144 * @param prop_name name of the property in which to store the phandle of
1146 * @param index index of the phandle to store
1147 * @param carveout information about the carveout to add
1148 * @param name base name of the reserved-memory node to create
1149 * @param compatibles compatible strings to set for the carveout
1150 * @param count number of compatible strings
1151 * @param flags bitmask of flags to set for the carveout
1152 * @return 0 on success or a negative error code on failure
1154 int fdtdec_set_carveout(void *blob, const char *node, const char *prop_name,
1155 unsigned int index, const struct fdt_memory *carveout,
1156 const char *name, const char **compatibles,
1157 unsigned int count, unsigned long flags);
1160 * Set up the device tree ready for use
1162 int fdtdec_setup(void);
1165 * Perform board-specific early DT adjustments
1167 int fdtdec_board_setup(const void *fdt_blob);
1169 #if CONFIG_IS_ENABLED(MULTI_DTB_FIT)
1171 * fdtdec_resetup() - Set up the device tree again
1173 * The main difference with fdtdec_setup() is that it returns if the fdt has
1174 * changed because a better match has been found.
1175 * This is typically used for boards that rely on a DM driver to detect the
1176 * board type. This function sould be called by the board code after the stuff
1177 * needed by board_fit_config_name_match() to operate porperly is available.
1178 * If this functions signals that a rescan is necessary, the board code must
1179 * unbind all the drivers using dm_uninit() and then rescan the DT with
1180 * dm_init_and_scan().
1182 * @param rescan Returns a flag indicating that fdt has changed and rescanning
1183 * the fdt is required
1185 * @return 0 if OK, -ve on error
1187 int fdtdec_resetup(int *rescan);
1191 * Board-specific FDT initialization. Returns the address to a device tree blob.
1193 * Called when CONFIG_OF_BOARD is defined.
1195 * The existing devicetree is available at gd->fdt_blob
1197 * @err internal error code if we fail to setup a DTB
1198 * @returns new devicetree blob pointer
1200 void *board_fdt_blob_setup(int *err);
1203 * Decode the size of memory
1205 * RAM size is normally set in a /memory node and consists of a list of
1206 * (base, size) cells in the 'reg' property. This information is used to
1207 * determine the total available memory as well as the address and size
1210 * Optionally the memory configuration can vary depending on a board id,
1211 * typically read from strapping resistors or an EEPROM on the board.
1213 * Finally, memory size can be detected (within certain limits) by probing
1214 * the available memory. It is safe to do so within the limits provides by
1215 * the board's device tree information. This makes it possible to produce
1216 * boards with different memory sizes, where the device tree specifies the
1217 * maximum memory configuration, and the smaller memory configuration is
1220 * This function decodes that information, returning the memory base address,
1221 * size and bank information. See the memory.txt binding for full
1224 * @param blob Device tree blob
1225 * @param area Name of node to check (NULL means "/memory")
1226 * @param board_id Board ID to look up
1227 * @param basep Returns base address of first memory bank (NULL to
1229 * @param sizep Returns total memory size (NULL to ignore)
1230 * @param bd Updated with the memory bank information (NULL to skip)
1231 * @return 0 if OK, -ve on error
1233 int fdtdec_decode_ram_size(const void *blob, const char *area, int board_id,
1234 phys_addr_t *basep, phys_size_t *sizep,
1235 struct bd_info *bd);
1238 * fdtdec_get_srcname() - Get the name of where the devicetree comes from
1240 * @return source name
1242 const char *fdtdec_get_srcname(void);