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_EXYNOS5_DP, /* Exynos Display port controller */
83 COMPAT_SAMSUNG_EXYNOS5_DWMMC, /* Exynos5 DWMMC controller */
84 COMPAT_SAMSUNG_EXYNOS_SERIAL, /* Exynos UART */
85 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */
86 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */
87 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */
88 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */
89 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */
90 COMPAT_SAMSUNG_EXYNOS5_I2C, /* Exynos5 High Speed I2C Controller */
91 COMPAT_SANDBOX_HOST_EMULATION, /* Sandbox emulation of a function */
96 /* GPIOs are numbered from 0 */
98 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
100 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
103 /* This is the state of a GPIO pin as defined by the fdt */
104 struct fdt_gpio_state {
105 const char *name; /* name of the fdt property defining this */
106 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
107 u8 flags; /* FDT_GPIO_... flags */
110 /* This tells us whether a fdt_gpio_state record is valid or not */
111 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
114 * Read the GPIO taking into account the polarity of the pin.
116 * @param gpio pointer to the decoded gpio
117 * @return value of the gpio if successful, < 0 if unsuccessful
119 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
122 * Write the GPIO taking into account the polarity of the pin.
124 * @param gpio pointer to the decoded gpio
125 * @return 0 if successful
127 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
130 * Find the next numbered alias for a peripheral. This is used to enumerate
131 * all the peripherals of a certain type.
133 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
134 * this function will return a pointer to the node the alias points to, and
135 * then update *upto to 1. Next time you call this function, the next node
138 * All nodes returned will match the compatible ID, as it is assumed that
139 * all peripherals use the same driver.
141 * @param blob FDT blob to use
142 * @param name Root name of alias to search for
143 * @param id Compatible ID to look for
144 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
146 int fdtdec_next_alias(const void *blob, const char *name,
147 enum fdt_compat_id id, int *upto);
150 * Find the compatible ID for a given node.
152 * Generally each node has at least one compatible string attached to it.
153 * This function looks through our list of known compatible strings and
154 * returns the corresponding ID which matches the compatible string.
156 * @param blob FDT blob to use
157 * @param node Node containing compatible string to find
158 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
160 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
163 * Find the next compatible node for a peripheral.
165 * Do the first call with node = 0. This function will return a pointer to
166 * the next compatible node. Next time you call this function, pass the
167 * value returned, and the next node will be provided.
169 * @param blob FDT blob to use
170 * @param node Start node for search
171 * @param id Compatible ID to look for (enum fdt_compat_id)
172 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
174 int fdtdec_next_compatible(const void *blob, int node,
175 enum fdt_compat_id id);
178 * Find the next compatible subnode for a peripheral.
180 * Do the first call with node set to the parent and depth = 0. This
181 * function will return the offset of the next compatible node. Next time
182 * you call this function, pass the node value returned last time, with
183 * depth unchanged, and the next node will be provided.
185 * @param blob FDT blob to use
186 * @param node Start node for search
187 * @param id Compatible ID to look for (enum fdt_compat_id)
188 * @param depthp Current depth (set to 0 before first call)
189 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
191 int fdtdec_next_compatible_subnode(const void *blob, int node,
192 enum fdt_compat_id id, int *depthp);
195 * Look up an address property in a node and return it as an address.
196 * The property must hold either one address with no trailing data or
197 * one address with a length. This is only tested on 32-bit machines.
199 * @param blob FDT blob
200 * @param node node to examine
201 * @param prop_name name of property to find
202 * @return address, if found, or FDT_ADDR_T_NONE if not
204 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
205 const char *prop_name);
208 * Look up an address property in a node and return it as an address.
209 * The property must hold one address with a length. This is only tested
210 * on 32-bit machines.
212 * @param blob FDT blob
213 * @param node node to examine
214 * @param prop_name name of property to find
215 * @return address, if found, or FDT_ADDR_T_NONE if not
217 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
218 const char *prop_name, fdt_size_t *sizep);
221 * Look up a 32-bit integer property in a node and return it. The property
222 * must have at least 4 bytes of data. The value of the first cell is
225 * @param blob FDT blob
226 * @param node node to examine
227 * @param prop_name name of property to find
228 * @param default_val default value to return if the property is not found
229 * @return integer value, if found, or default_val if not
231 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
235 * Look up a 64-bit integer property in a node and return it. The property
236 * must have at least 8 bytes of data (2 cells). The first two cells are
237 * concatenated to form a 8 bytes value, where the first cell is top half and
238 * the second cell is bottom half.
240 * @param blob FDT blob
241 * @param node node to examine
242 * @param prop_name name of property to find
243 * @param default_val default value to return if the property is not found
244 * @return integer value, if found, or default_val if not
246 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
247 uint64_t default_val);
250 * Checks whether a node is enabled.
251 * This looks for a 'status' property. If this exists, then returns 1 if
252 * the status is 'ok' and 0 otherwise. If there is no status property,
253 * it returns 1 on the assumption that anything mentioned should be enabled
256 * @param blob FDT blob
257 * @param node node to examine
258 * @return integer value 0 (not enabled) or 1 (enabled)
260 int fdtdec_get_is_enabled(const void *blob, int node);
263 * Make sure we have a valid fdt available to control U-Boot.
265 * If not, a message is printed to the console if the console is ready.
267 * @return 0 if all ok, -1 if not
269 int fdtdec_prepare_fdt(void);
272 * Checks that we have a valid fdt available to control U-Boot.
274 * However, if not then for the moment nothing is done, since this function
275 * is called too early to panic().
279 int fdtdec_check_fdt(void);
282 * Find the nodes for a peripheral and return a list of them in the correct
283 * order. This is used to enumerate all the peripherals of a certain type.
285 * To use this, optionally set up a /aliases node with alias properties for
286 * a peripheral. For example, for usb you could have:
289 * usb0 = "/ehci@c5008000";
290 * usb1 = "/ehci@c5000000";
293 * Pass "usb" as the name to this function and will return a list of two
294 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
296 * All nodes returned will match the compatible ID, as it is assumed that
297 * all peripherals use the same driver.
299 * If no alias node is found, then the node list will be returned in the
300 * order found in the fdt. If the aliases mention a node which doesn't
301 * exist, then this will be ignored. If nodes are found with no aliases,
302 * they will be added in any order.
304 * If there is a gap in the aliases, then this function return a 0 node at
305 * that position. The return value will also count these gaps.
307 * This function checks node properties and will not return nodes which are
308 * marked disabled (status = "disabled").
310 * @param blob FDT blob to use
311 * @param name Root name of alias to search for
312 * @param id Compatible ID to look for
313 * @param node_list Place to put list of found nodes
314 * @param maxcount Maximum number of nodes to find
315 * @return number of nodes found on success, FTD_ERR_... on error
317 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
318 enum fdt_compat_id id, int *node_list, int maxcount);
321 * This function is similar to fdtdec_find_aliases_for_id() except that it
322 * adds to the node_list that is passed in. Any 0 elements are considered
323 * available for allocation - others are considered already used and are
326 * You can use this by calling fdtdec_find_aliases_for_id() with an
327 * uninitialised array, then setting the elements that are returned to -1,
328 * say, then calling this function, perhaps with a different compat id.
329 * Any elements you get back that are >0 are new nodes added by the call
332 * Note that if you have some nodes with aliases and some without, you are
333 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
334 * one compat_id may fill in positions for which you have aliases defined
335 * for another compat_id. When you later call *this* function with the second
336 * compat_id, the alias positions may already be used. A debug warning may
337 * be generated in this case, but it is safest to define aliases for all
338 * nodes when you care about the ordering.
340 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
341 enum fdt_compat_id id, int *node_list, int maxcount);
344 * Get the name for a compatible ID
346 * @param id Compatible ID to look for
347 * @return compatible string for that id
349 const char *fdtdec_get_compatible(enum fdt_compat_id id);
351 /* Look up a phandle and follow it to its node. Then return the offset
354 * @param blob FDT blob
355 * @param node node to examine
356 * @param prop_name name of property to find
357 * @return node offset if found, -ve error code on error
359 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
362 * Look up a property in a node and return its contents in an integer
363 * array of given length. The property must have at least enough data for
364 * the array (4*count bytes). It may have more, but this will be ignored.
366 * @param blob FDT blob
367 * @param node node to examine
368 * @param prop_name name of property to find
369 * @param array array to fill with data
370 * @param count number of array elements
371 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
372 * or -FDT_ERR_BADLAYOUT if not enough data
374 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
375 u32 *array, int count);
378 * Look up a property in a node and return a pointer to its contents as a
379 * unsigned int array of given length. The property must have at least enough
380 * data for the array ('count' cells). It may have more, but this will be
381 * ignored. The data is not copied.
383 * Note that you must access elements of the array with fdt32_to_cpu(),
384 * since the elements will be big endian even on a little endian machine.
386 * @param blob FDT blob
387 * @param node node to examine
388 * @param prop_name name of property to find
389 * @param count number of array elements
390 * @return pointer to array if found, or NULL if the property is not
391 * found or there is not enough data
393 const u32 *fdtdec_locate_array(const void *blob, int node,
394 const char *prop_name, int count);
397 * Look up a boolean property in a node and return it.
399 * A boolean properly is true if present in the device tree and false if not
400 * present, regardless of its value.
402 * @param blob FDT blob
403 * @param node node to examine
404 * @param prop_name name of property to find
405 * @return 1 if the properly is present; 0 if it isn't present
407 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
410 * Decode a single GPIOs from an FDT.
412 * If the property is not found, then the GPIO structure will still be
413 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
414 * provide optional GPIOs.
416 * @param blob FDT blob to use
417 * @param node Node to look at
418 * @param prop_name Node property name
419 * @param gpio gpio elements to fill from FDT
420 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
422 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
423 struct fdt_gpio_state *gpio);
426 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
429 * @param blob FDT blob to use
430 * @param node Node to look at
431 * @param prop_name Node property name
432 * @param gpio Array of gpio elements to fill from FDT. This will be
433 * untouched if either 0 or an error is returned
434 * @param max_count Maximum number of elements allowed
435 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
436 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
438 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
439 struct fdt_gpio_state *gpio, int max_count);
442 * Set up a GPIO pin according to the provided gpio information. At present this
443 * just requests the GPIO.
445 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
446 * deal with optional GPIOs.
448 * @param gpio GPIO info to use for set up
449 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
451 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
454 * Look in the FDT for a config item with the given name and return its value
455 * as a 32-bit integer. The property must have at least 4 bytes of data. The
456 * value of the first cell is returned.
458 * @param blob FDT blob to use
459 * @param prop_name Node property name
460 * @param default_val default value to return if the property is not found
461 * @return integer value, if found, or default_val if not
463 int fdtdec_get_config_int(const void *blob, const char *prop_name,
467 * Look in the FDT for a config item with the given name
468 * and return whether it exists.
470 * @param blob FDT blob
471 * @param prop_name property name to look up
472 * @return 1, if it exists, or 0 if not
474 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
477 * Look in the FDT for a config item with the given name and return its value
480 * @param blob FDT blob
481 * @param prop_name property name to look up
482 * @returns property string, NULL on error.
484 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
487 * Look up a property in a node and return its contents in a byte
488 * array of given length. The property must have at least enough data for
489 * the array (count bytes). It may have more, but this will be ignored.
491 * @param blob FDT blob
492 * @param node node to examine
493 * @param prop_name name of property to find
494 * @param array array to fill with data
495 * @param count number of array elements
496 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
497 * or -FDT_ERR_BADLAYOUT if not enough data
499 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
500 u8 *array, int count);
503 * Look up a property in a node and return a pointer to its contents as a
504 * byte array of given length. The property must have at least enough data
505 * for the array (count bytes). It may have more, but this will be ignored.
506 * The data is not copied.
508 * @param blob FDT blob
509 * @param node node to examine
510 * @param prop_name name of property to find
511 * @param count number of array elements
512 * @return pointer to byte array if found, or NULL if the property is not
513 * found or there is not enough data
515 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
516 const char *prop_name, int count);
519 * Look up a property in a node which contains a memory region address and
520 * size. Then return a pointer to this address.
522 * The property must hold one address with a length. This is only tested on
525 * @param blob FDT blob
526 * @param node node to examine
527 * @param prop_name name of property to find
528 * @param ptrp returns pointer to region, or NULL if no address
529 * @param size returns size of region
530 * @return 0 if ok, -1 on error (propery not found)
532 int fdtdec_decode_region(const void *blob, int node,
533 const char *prop_name, void **ptrp, size_t *size);
535 /* A flash map entry, containing an offset and length */
542 * Read a flash entry from the fdt
544 * @param blob FDT blob
545 * @param node Offset of node to read
546 * @param name Name of node being read
547 * @param entry Place to put offset and size of this node
548 * @return 0 if ok, -ve on error
550 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
551 struct fmap_entry *entry);