2 * Copyright (c) 2011 The Chromium OS Authors.
3 * SPDX-License-Identifier: GPL-2.0+
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.
20 * A typedef for a physical address. Note that fdt data is always big
21 * endian even on a litle endian machine.
23 #ifdef CONFIG_PHYS_64BIT
24 typedef u64 fdt_addr_t;
25 typedef u64 fdt_size_t;
26 #define FDT_ADDR_T_NONE (-1ULL)
27 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
28 #define fdt_size_to_cpu(reg) be64_to_cpu(reg)
30 typedef u32 fdt_addr_t;
31 typedef u32 fdt_size_t;
32 #define FDT_ADDR_T_NONE (-1U)
33 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
34 #define fdt_size_to_cpu(reg) be32_to_cpu(reg)
37 /* Information obtained about memory from the FDT */
44 * Compat types that we know about and for which we might have drivers.
45 * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
50 COMPAT_NVIDIA_TEGRA20_USB, /* Tegra20 USB port */
51 COMPAT_NVIDIA_TEGRA30_USB, /* Tegra30 USB port */
52 COMPAT_NVIDIA_TEGRA114_USB, /* Tegra114 USB port */
53 COMPAT_NVIDIA_TEGRA114_I2C, /* Tegra114 I2C w/single clock source */
54 COMPAT_NVIDIA_TEGRA20_I2C, /* Tegra20 i2c */
55 COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra20 dvc (really just i2c) */
56 COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */
57 COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
58 COMPAT_NVIDIA_TEGRA20_KBC, /* Tegra20 Keyboard */
59 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */
60 COMPAT_NVIDIA_TEGRA20_PWM, /* Tegra 2 PWM controller */
61 COMPAT_NVIDIA_TEGRA20_DC, /* Tegra 2 Display controller */
62 COMPAT_NVIDIA_TEGRA124_SDMMC, /* Tegra124 SDMMC controller */
63 COMPAT_NVIDIA_TEGRA30_SDMMC, /* Tegra30 SDMMC controller */
64 COMPAT_NVIDIA_TEGRA20_SDMMC, /* Tegra20 SDMMC controller */
65 COMPAT_NVIDIA_TEGRA20_SFLASH, /* Tegra 2 SPI flash controller */
66 COMPAT_NVIDIA_TEGRA20_SLINK, /* Tegra 2 SPI SLINK controller */
67 COMPAT_NVIDIA_TEGRA114_SPI, /* Tegra 114 SPI controller */
68 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */
69 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */
70 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */
71 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */
72 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */
73 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */
74 COMPAT_GOOGLE_CROS_EC, /* Google CROS_EC Protocol */
75 COMPAT_GOOGLE_CROS_EC_KEYB, /* Google CROS_EC Keyboard */
76 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */
77 COMPAT_SAMSUNG_EXYNOS5_XHCI, /* Exynos5 XHCI controller */
78 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */
79 COMPAT_SAMSUNG_EXYNOS5_USB3_PHY,/* Exynos phy controller for usb3.0 */
80 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */
81 COMPAT_SAMSUNG_EXYNOS_FIMD, /* Exynos Display controller */
82 COMPAT_SAMSUNG_EXYNOS_MIPI_DSI, /* Exynos mipi dsi */
83 COMPAT_SAMSUNG_EXYNOS5_DP, /* Exynos Display port controller */
84 COMPAT_SAMSUNG_EXYNOS_DWMMC, /* Exynos DWMMC controller */
85 COMPAT_SAMSUNG_EXYNOS_MMC, /* Exynos MMC controller */
86 COMPAT_SAMSUNG_EXYNOS_SERIAL, /* Exynos UART */
87 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */
88 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */
89 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */
90 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */
91 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */
92 COMPAT_SAMSUNG_EXYNOS5_I2C, /* Exynos5 High Speed I2C Controller */
93 COMPAT_SANDBOX_HOST_EMULATION, /* Sandbox emulation of a function */
94 COMPAT_SANDBOX_LCD_SDL, /* Sandbox LCD emulation with SDL */
95 COMPAT_TI_TPS65090, /* Texas Instrument TPS65090 */
96 COMPAT_NXP_PTN3460, /* NXP PTN3460 DP/LVDS bridge */
97 COMPAT_SAMSUNG_EXYNOS_SYSMMU, /* Exynos sysmmu */
98 COMPAT_PARADE_PS8625, /* Parade PS8622 EDP->LVDS bridge */
99 COMPAT_INTEL_LPC, /* Intel Low Pin Count I/F */
104 /* GPIOs are numbered from 0 */
106 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
108 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
111 /* This is the state of a GPIO pin as defined by the fdt */
112 struct fdt_gpio_state {
113 const char *name; /* name of the fdt property defining this */
114 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
115 u8 flags; /* FDT_GPIO_... flags */
118 /* This tells us whether a fdt_gpio_state record is valid or not */
119 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
122 * Read the GPIO taking into account the polarity of the pin.
124 * @param gpio pointer to the decoded gpio
125 * @return value of the gpio if successful, < 0 if unsuccessful
127 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
130 * Write the GPIO taking into account the polarity of the pin.
132 * @param gpio pointer to the decoded gpio
133 * @return 0 if successful
135 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
138 * Find the next numbered alias for a peripheral. This is used to enumerate
139 * all the peripherals of a certain type.
141 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
142 * this function will return a pointer to the node the alias points to, and
143 * then update *upto to 1. Next time you call this function, the next node
146 * All nodes returned will match the compatible ID, as it is assumed that
147 * all peripherals use the same driver.
149 * @param blob FDT blob to use
150 * @param name Root name of alias to search for
151 * @param id Compatible ID to look for
152 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
154 int fdtdec_next_alias(const void *blob, const char *name,
155 enum fdt_compat_id id, int *upto);
158 * Find the compatible ID for a given node.
160 * Generally each node has at least one compatible string attached to it.
161 * This function looks through our list of known compatible strings and
162 * returns the corresponding ID which matches the compatible string.
164 * @param blob FDT blob to use
165 * @param node Node containing compatible string to find
166 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
168 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
171 * Find the next compatible node for a peripheral.
173 * Do the first call with node = 0. This function will return a pointer to
174 * the next compatible node. Next time you call this function, pass the
175 * value returned, and the next node will be provided.
177 * @param blob FDT blob to use
178 * @param node Start node for search
179 * @param id Compatible ID to look for (enum fdt_compat_id)
180 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
182 int fdtdec_next_compatible(const void *blob, int node,
183 enum fdt_compat_id id);
186 * Find the next compatible subnode for a peripheral.
188 * Do the first call with node set to the parent and depth = 0. This
189 * function will return the offset of the next compatible node. Next time
190 * you call this function, pass the node value returned last time, with
191 * depth unchanged, and the next node will be provided.
193 * @param blob FDT blob to use
194 * @param node Start node for search
195 * @param id Compatible ID to look for (enum fdt_compat_id)
196 * @param depthp Current depth (set to 0 before first call)
197 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
199 int fdtdec_next_compatible_subnode(const void *blob, int node,
200 enum fdt_compat_id id, int *depthp);
203 * Look up an address property in a node and return it as an address.
204 * The property must hold either one address with no trailing data or
205 * one address with a length. This is only tested on 32-bit machines.
207 * @param blob FDT blob
208 * @param node node to examine
209 * @param prop_name name of property to find
210 * @return address, if found, or FDT_ADDR_T_NONE if not
212 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
213 const char *prop_name);
216 * Look up an address property in a node and return it as an address.
217 * The property must hold one address with a length. This is only tested
218 * on 32-bit machines.
220 * @param blob FDT blob
221 * @param node node to examine
222 * @param prop_name name of property to find
223 * @return address, if found, or FDT_ADDR_T_NONE if not
225 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
226 const char *prop_name, fdt_size_t *sizep);
229 * Look up a 32-bit integer property in a node and return it. The property
230 * must have at least 4 bytes of data. The value of the first cell is
233 * @param blob FDT blob
234 * @param node node to examine
235 * @param prop_name name of property to find
236 * @param default_val default value to return if the property is not found
237 * @return integer value, if found, or default_val if not
239 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
243 * Look up a 64-bit integer property in a node and return it. The property
244 * must have at least 8 bytes of data (2 cells). The first two cells are
245 * concatenated to form a 8 bytes value, where the first cell is top half and
246 * the second cell is bottom half.
248 * @param blob FDT blob
249 * @param node node to examine
250 * @param prop_name name of property to find
251 * @param default_val default value to return if the property is not found
252 * @return integer value, if found, or default_val if not
254 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
255 uint64_t default_val);
258 * Checks whether a node is enabled.
259 * This looks for a 'status' property. If this exists, then returns 1 if
260 * the status is 'ok' and 0 otherwise. If there is no status property,
261 * it returns 1 on the assumption that anything mentioned should be enabled
264 * @param blob FDT blob
265 * @param node node to examine
266 * @return integer value 0 (not enabled) or 1 (enabled)
268 int fdtdec_get_is_enabled(const void *blob, int node);
271 * Make sure we have a valid fdt available to control U-Boot.
273 * If not, a message is printed to the console if the console is ready.
275 * @return 0 if all ok, -1 if not
277 int fdtdec_prepare_fdt(void);
280 * Checks that we have a valid fdt available to control U-Boot.
282 * However, if not then for the moment nothing is done, since this function
283 * is called too early to panic().
287 int fdtdec_check_fdt(void);
290 * Find the nodes for a peripheral and return a list of them in the correct
291 * order. This is used to enumerate all the peripherals of a certain type.
293 * To use this, optionally set up a /aliases node with alias properties for
294 * a peripheral. For example, for usb you could have:
297 * usb0 = "/ehci@c5008000";
298 * usb1 = "/ehci@c5000000";
301 * Pass "usb" as the name to this function and will return a list of two
302 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
304 * All nodes returned will match the compatible ID, as it is assumed that
305 * all peripherals use the same driver.
307 * If no alias node is found, then the node list will be returned in the
308 * order found in the fdt. If the aliases mention a node which doesn't
309 * exist, then this will be ignored. If nodes are found with no aliases,
310 * they will be added in any order.
312 * If there is a gap in the aliases, then this function return a 0 node at
313 * that position. The return value will also count these gaps.
315 * This function checks node properties and will not return nodes which are
316 * marked disabled (status = "disabled").
318 * @param blob FDT blob to use
319 * @param name Root name of alias to search for
320 * @param id Compatible ID to look for
321 * @param node_list Place to put list of found nodes
322 * @param maxcount Maximum number of nodes to find
323 * @return number of nodes found on success, FTD_ERR_... on error
325 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
326 enum fdt_compat_id id, int *node_list, int maxcount);
329 * This function is similar to fdtdec_find_aliases_for_id() except that it
330 * adds to the node_list that is passed in. Any 0 elements are considered
331 * available for allocation - others are considered already used and are
334 * You can use this by calling fdtdec_find_aliases_for_id() with an
335 * uninitialised array, then setting the elements that are returned to -1,
336 * say, then calling this function, perhaps with a different compat id.
337 * Any elements you get back that are >0 are new nodes added by the call
340 * Note that if you have some nodes with aliases and some without, you are
341 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
342 * one compat_id may fill in positions for which you have aliases defined
343 * for another compat_id. When you later call *this* function with the second
344 * compat_id, the alias positions may already be used. A debug warning may
345 * be generated in this case, but it is safest to define aliases for all
346 * nodes when you care about the ordering.
348 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
349 enum fdt_compat_id id, int *node_list, int maxcount);
352 * Get the alias sequence number of a node
354 * This works out whether a node is pointed to by an alias, and if so, the
355 * sequence number of that alias. Aliases are of the form <base><num> where
356 * <num> is the sequence number. For example spi2 would be sequence number
359 * @param blob Device tree blob (if NULL, then error is returned)
360 * @param base Base name for alias (before the underscore)
361 * @param node Node to look up
362 * @param seqp This is set to the sequence number if one is found,
363 * but otherwise the value is left alone
364 * @return 0 if a sequence was found, -ve if not
366 int fdtdec_get_alias_seq(const void *blob, const char *base, int node,
370 * Get the offset of the given alias node
372 * This looks up an alias in /aliases then finds the offset of that node.
374 * @param blob Device tree blob (if NULL, then error is returned)
375 * @param name Alias name, e.g. "console"
376 * @return Node offset referred to by that alias, or -ve FDT_ERR_...
378 int fdtdec_get_alias_node(const void *blob, const char *name);
381 * Get the offset of the given chosen node
383 * This looks up a property in /chosen containing the path to another node,
384 * then finds the offset of that node.
386 * @param blob Device tree blob (if NULL, then error is returned)
387 * @param name Property name, e.g. "stdout-path"
388 * @return Node offset referred to by that chosen node, or -ve FDT_ERR_...
390 int fdtdec_get_chosen_node(const void *blob, const char *name);
393 * Get the name for a compatible ID
395 * @param id Compatible ID to look for
396 * @return compatible string for that id
398 const char *fdtdec_get_compatible(enum fdt_compat_id id);
400 /* Look up a phandle and follow it to its node. Then return the offset
403 * @param blob FDT blob
404 * @param node node to examine
405 * @param prop_name name of property to find
406 * @return node offset if found, -ve error code on error
408 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
411 * Look up a property in a node and return its contents in an integer
412 * array of given length. The property must have at least enough data for
413 * the array (4*count bytes). It may have more, but this will be ignored.
415 * @param blob FDT blob
416 * @param node node to examine
417 * @param prop_name name of property to find
418 * @param array array to fill with data
419 * @param count number of array elements
420 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
421 * or -FDT_ERR_BADLAYOUT if not enough data
423 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
424 u32 *array, int count);
427 * Look up a property in a node and return a pointer to its contents as a
428 * unsigned int array of given length. The property must have at least enough
429 * data for the array ('count' cells). It may have more, but this will be
430 * ignored. The data is not copied.
432 * Note that you must access elements of the array with fdt32_to_cpu(),
433 * since the elements will be big endian even on a little endian machine.
435 * @param blob FDT blob
436 * @param node node to examine
437 * @param prop_name name of property to find
438 * @param count number of array elements
439 * @return pointer to array if found, or NULL if the property is not
440 * found or there is not enough data
442 const u32 *fdtdec_locate_array(const void *blob, int node,
443 const char *prop_name, int count);
446 * Look up a boolean property in a node and return it.
448 * A boolean properly is true if present in the device tree and false if not
449 * present, regardless of its value.
451 * @param blob FDT blob
452 * @param node node to examine
453 * @param prop_name name of property to find
454 * @return 1 if the properly is present; 0 if it isn't present
456 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
459 * Decode a single GPIOs from an FDT.
461 * If the property is not found, then the GPIO structure will still be
462 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
463 * provide optional GPIOs.
465 * @param blob FDT blob to use
466 * @param node Node to look at
467 * @param prop_name Node property name
468 * @param gpio gpio elements to fill from FDT
469 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
471 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
472 struct fdt_gpio_state *gpio);
475 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
478 * @param blob FDT blob to use
479 * @param node Node to look at
480 * @param prop_name Node property name
481 * @param gpio Array of gpio elements to fill from FDT. This will be
482 * untouched if either 0 or an error is returned
483 * @param max_count Maximum number of elements allowed
484 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
485 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
487 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
488 struct fdt_gpio_state *gpio, int max_count);
491 * Set up a GPIO pin according to the provided gpio information. At present this
492 * just requests the GPIO.
494 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
495 * deal with optional GPIOs.
497 * @param gpio GPIO info to use for set up
498 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
500 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
503 * Look in the FDT for a config item with the given name and return its value
504 * as a 32-bit integer. The property must have at least 4 bytes of data. The
505 * value of the first cell is returned.
507 * @param blob FDT blob to use
508 * @param prop_name Node property name
509 * @param default_val default value to return if the property is not found
510 * @return integer value, if found, or default_val if not
512 int fdtdec_get_config_int(const void *blob, const char *prop_name,
516 * Look in the FDT for a config item with the given name
517 * and return whether it exists.
519 * @param blob FDT blob
520 * @param prop_name property name to look up
521 * @return 1, if it exists, or 0 if not
523 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
526 * Look in the FDT for a config item with the given name and return its value
529 * @param blob FDT blob
530 * @param prop_name property name to look up
531 * @returns property string, NULL on error.
533 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
536 * Look up a property in a node and return its contents in a byte
537 * array of given length. The property must have at least enough data for
538 * the array (count bytes). It may have more, but this will be ignored.
540 * @param blob FDT blob
541 * @param node node to examine
542 * @param prop_name name of property to find
543 * @param array array to fill with data
544 * @param count number of array elements
545 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
546 * or -FDT_ERR_BADLAYOUT if not enough data
548 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
549 u8 *array, int count);
552 * Look up a property in a node and return a pointer to its contents as a
553 * byte array of given length. The property must have at least enough data
554 * for the array (count bytes). It may have more, but this will be ignored.
555 * The data is not copied.
557 * @param blob FDT blob
558 * @param node node to examine
559 * @param prop_name name of property to find
560 * @param count number of array elements
561 * @return pointer to byte array if found, or NULL if the property is not
562 * found or there is not enough data
564 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
565 const char *prop_name, int count);
568 * Look up a property in a node which contains a memory region address and
569 * size. Then return a pointer to this address.
571 * The property must hold one address with a length. This is only tested on
574 * @param blob FDT blob
575 * @param node node to examine
576 * @param prop_name name of property to find
577 * @param ptrp returns pointer to region, or NULL if no address
578 * @param size returns size of region
579 * @return 0 if ok, -1 on error (propery not found)
581 int fdtdec_decode_region(const void *blob, int node,
582 const char *prop_name, void **ptrp, size_t *size);
584 /* A flash map entry, containing an offset and length */
591 * Read a flash entry from the fdt
593 * @param blob FDT blob
594 * @param node Offset of node to read
595 * @param name Name of node being read
596 * @param entry Place to put offset and size of this node
597 * @return 0 if ok, -ve on error
599 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
600 struct fmap_entry *entry);