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 */
101 /* GPIOs are numbered from 0 */
103 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
105 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
108 /* This is the state of a GPIO pin as defined by the fdt */
109 struct fdt_gpio_state {
110 const char *name; /* name of the fdt property defining this */
111 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
112 u8 flags; /* FDT_GPIO_... flags */
115 /* This tells us whether a fdt_gpio_state record is valid or not */
116 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
119 * Read the GPIO taking into account the polarity of the pin.
121 * @param gpio pointer to the decoded gpio
122 * @return value of the gpio if successful, < 0 if unsuccessful
124 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
127 * Write the GPIO taking into account the polarity of the pin.
129 * @param gpio pointer to the decoded gpio
130 * @return 0 if successful
132 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
135 * Find the next numbered alias for a peripheral. This is used to enumerate
136 * all the peripherals of a certain type.
138 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
139 * this function will return a pointer to the node the alias points to, and
140 * then update *upto to 1. Next time you call this function, the next node
143 * All nodes returned will match the compatible ID, as it is assumed that
144 * all peripherals use the same driver.
146 * @param blob FDT blob to use
147 * @param name Root name of alias to search for
148 * @param id Compatible ID to look for
149 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
151 int fdtdec_next_alias(const void *blob, const char *name,
152 enum fdt_compat_id id, int *upto);
155 * Find the compatible ID for a given node.
157 * Generally each node has at least one compatible string attached to it.
158 * This function looks through our list of known compatible strings and
159 * returns the corresponding ID which matches the compatible string.
161 * @param blob FDT blob to use
162 * @param node Node containing compatible string to find
163 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
165 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
168 * Find the next compatible node for a peripheral.
170 * Do the first call with node = 0. This function will return a pointer to
171 * the next compatible node. Next time you call this function, pass the
172 * value returned, and the next node will be provided.
174 * @param blob FDT blob to use
175 * @param node Start node for search
176 * @param id Compatible ID to look for (enum fdt_compat_id)
177 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
179 int fdtdec_next_compatible(const void *blob, int node,
180 enum fdt_compat_id id);
183 * Find the next compatible subnode for a peripheral.
185 * Do the first call with node set to the parent and depth = 0. This
186 * function will return the offset of the next compatible node. Next time
187 * you call this function, pass the node value returned last time, with
188 * depth unchanged, and the next node will be provided.
190 * @param blob FDT blob to use
191 * @param node Start node for search
192 * @param id Compatible ID to look for (enum fdt_compat_id)
193 * @param depthp Current depth (set to 0 before first call)
194 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
196 int fdtdec_next_compatible_subnode(const void *blob, int node,
197 enum fdt_compat_id id, int *depthp);
200 * Look up an address property in a node and return it as an address.
201 * The property must hold either one address with no trailing data or
202 * one address with a length. This is only tested on 32-bit machines.
204 * @param blob FDT blob
205 * @param node node to examine
206 * @param prop_name name of property to find
207 * @return address, if found, or FDT_ADDR_T_NONE if not
209 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
210 const char *prop_name);
213 * Look up an address property in a node and return it as an address.
214 * The property must hold one address with a length. This is only tested
215 * on 32-bit machines.
217 * @param blob FDT blob
218 * @param node node to examine
219 * @param prop_name name of property to find
220 * @return address, if found, or FDT_ADDR_T_NONE if not
222 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
223 const char *prop_name, fdt_size_t *sizep);
226 * Look up a 32-bit integer property in a node and return it. The property
227 * must have at least 4 bytes of data. The value of the first cell is
230 * @param blob FDT blob
231 * @param node node to examine
232 * @param prop_name name of property to find
233 * @param default_val default value to return if the property is not found
234 * @return integer value, if found, or default_val if not
236 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
240 * Look up a 64-bit integer property in a node and return it. The property
241 * must have at least 8 bytes of data (2 cells). The first two cells are
242 * concatenated to form a 8 bytes value, where the first cell is top half and
243 * the second cell is bottom half.
245 * @param blob FDT blob
246 * @param node node to examine
247 * @param prop_name name of property to find
248 * @param default_val default value to return if the property is not found
249 * @return integer value, if found, or default_val if not
251 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
252 uint64_t default_val);
255 * Checks whether a node is enabled.
256 * This looks for a 'status' property. If this exists, then returns 1 if
257 * the status is 'ok' and 0 otherwise. If there is no status property,
258 * it returns 1 on the assumption that anything mentioned should be enabled
261 * @param blob FDT blob
262 * @param node node to examine
263 * @return integer value 0 (not enabled) or 1 (enabled)
265 int fdtdec_get_is_enabled(const void *blob, int node);
268 * Make sure we have a valid fdt available to control U-Boot.
270 * If not, a message is printed to the console if the console is ready.
272 * @return 0 if all ok, -1 if not
274 int fdtdec_prepare_fdt(void);
277 * Checks that we have a valid fdt available to control U-Boot.
279 * However, if not then for the moment nothing is done, since this function
280 * is called too early to panic().
284 int fdtdec_check_fdt(void);
287 * Find the nodes for a peripheral and return a list of them in the correct
288 * order. This is used to enumerate all the peripherals of a certain type.
290 * To use this, optionally set up a /aliases node with alias properties for
291 * a peripheral. For example, for usb you could have:
294 * usb0 = "/ehci@c5008000";
295 * usb1 = "/ehci@c5000000";
298 * Pass "usb" as the name to this function and will return a list of two
299 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
301 * All nodes returned will match the compatible ID, as it is assumed that
302 * all peripherals use the same driver.
304 * If no alias node is found, then the node list will be returned in the
305 * order found in the fdt. If the aliases mention a node which doesn't
306 * exist, then this will be ignored. If nodes are found with no aliases,
307 * they will be added in any order.
309 * If there is a gap in the aliases, then this function return a 0 node at
310 * that position. The return value will also count these gaps.
312 * This function checks node properties and will not return nodes which are
313 * marked disabled (status = "disabled").
315 * @param blob FDT blob to use
316 * @param name Root name of alias to search for
317 * @param id Compatible ID to look for
318 * @param node_list Place to put list of found nodes
319 * @param maxcount Maximum number of nodes to find
320 * @return number of nodes found on success, FTD_ERR_... on error
322 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
323 enum fdt_compat_id id, int *node_list, int maxcount);
326 * This function is similar to fdtdec_find_aliases_for_id() except that it
327 * adds to the node_list that is passed in. Any 0 elements are considered
328 * available for allocation - others are considered already used and are
331 * You can use this by calling fdtdec_find_aliases_for_id() with an
332 * uninitialised array, then setting the elements that are returned to -1,
333 * say, then calling this function, perhaps with a different compat id.
334 * Any elements you get back that are >0 are new nodes added by the call
337 * Note that if you have some nodes with aliases and some without, you are
338 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
339 * one compat_id may fill in positions for which you have aliases defined
340 * for another compat_id. When you later call *this* function with the second
341 * compat_id, the alias positions may already be used. A debug warning may
342 * be generated in this case, but it is safest to define aliases for all
343 * nodes when you care about the ordering.
345 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
346 enum fdt_compat_id id, int *node_list, int maxcount);
349 * Get the name for a compatible ID
351 * @param id Compatible ID to look for
352 * @return compatible string for that id
354 const char *fdtdec_get_compatible(enum fdt_compat_id id);
356 /* Look up a phandle and follow it to its node. Then return the offset
359 * @param blob FDT blob
360 * @param node node to examine
361 * @param prop_name name of property to find
362 * @return node offset if found, -ve error code on error
364 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
367 * Look up a property in a node and return its contents in an integer
368 * array of given length. The property must have at least enough data for
369 * the array (4*count bytes). It may have more, but this will be ignored.
371 * @param blob FDT blob
372 * @param node node to examine
373 * @param prop_name name of property to find
374 * @param array array to fill with data
375 * @param count number of array elements
376 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
377 * or -FDT_ERR_BADLAYOUT if not enough data
379 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
380 u32 *array, int count);
383 * Look up a property in a node and return a pointer to its contents as a
384 * unsigned int array of given length. The property must have at least enough
385 * data for the array ('count' cells). It may have more, but this will be
386 * ignored. The data is not copied.
388 * Note that you must access elements of the array with fdt32_to_cpu(),
389 * since the elements will be big endian even on a little endian machine.
391 * @param blob FDT blob
392 * @param node node to examine
393 * @param prop_name name of property to find
394 * @param count number of array elements
395 * @return pointer to array if found, or NULL if the property is not
396 * found or there is not enough data
398 const u32 *fdtdec_locate_array(const void *blob, int node,
399 const char *prop_name, int count);
402 * Look up a boolean property in a node and return it.
404 * A boolean properly is true if present in the device tree and false if not
405 * present, regardless of its value.
407 * @param blob FDT blob
408 * @param node node to examine
409 * @param prop_name name of property to find
410 * @return 1 if the properly is present; 0 if it isn't present
412 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
415 * Decode a single GPIOs from an FDT.
417 * If the property is not found, then the GPIO structure will still be
418 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
419 * provide optional GPIOs.
421 * @param blob FDT blob to use
422 * @param node Node to look at
423 * @param prop_name Node property name
424 * @param gpio gpio elements to fill from FDT
425 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
427 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
428 struct fdt_gpio_state *gpio);
431 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
434 * @param blob FDT blob to use
435 * @param node Node to look at
436 * @param prop_name Node property name
437 * @param gpio Array of gpio elements to fill from FDT. This will be
438 * untouched if either 0 or an error is returned
439 * @param max_count Maximum number of elements allowed
440 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
441 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
443 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
444 struct fdt_gpio_state *gpio, int max_count);
447 * Set up a GPIO pin according to the provided gpio information. At present this
448 * just requests the GPIO.
450 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
451 * deal with optional GPIOs.
453 * @param gpio GPIO info to use for set up
454 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
456 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
459 * Look in the FDT for a config item with the given name and return its value
460 * as a 32-bit integer. The property must have at least 4 bytes of data. The
461 * value of the first cell is returned.
463 * @param blob FDT blob to use
464 * @param prop_name Node property name
465 * @param default_val default value to return if the property is not found
466 * @return integer value, if found, or default_val if not
468 int fdtdec_get_config_int(const void *blob, const char *prop_name,
472 * Look in the FDT for a config item with the given name
473 * and return whether it exists.
475 * @param blob FDT blob
476 * @param prop_name property name to look up
477 * @return 1, if it exists, or 0 if not
479 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
482 * Look in the FDT for a config item with the given name and return its value
485 * @param blob FDT blob
486 * @param prop_name property name to look up
487 * @returns property string, NULL on error.
489 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
492 * Look up a property in a node and return its contents in a byte
493 * array of given length. The property must have at least enough data for
494 * the array (count bytes). It may have more, but this will be ignored.
496 * @param blob FDT blob
497 * @param node node to examine
498 * @param prop_name name of property to find
499 * @param array array to fill with data
500 * @param count number of array elements
501 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
502 * or -FDT_ERR_BADLAYOUT if not enough data
504 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
505 u8 *array, int count);
508 * Look up a property in a node and return a pointer to its contents as a
509 * byte array of given length. The property must have at least enough data
510 * for the array (count bytes). It may have more, but this will be ignored.
511 * The data is not copied.
513 * @param blob FDT blob
514 * @param node node to examine
515 * @param prop_name name of property to find
516 * @param count number of array elements
517 * @return pointer to byte array if found, or NULL if the property is not
518 * found or there is not enough data
520 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
521 const char *prop_name, int count);
524 * Look up a property in a node which contains a memory region address and
525 * size. Then return a pointer to this address.
527 * The property must hold one address with a length. This is only tested on
530 * @param blob FDT blob
531 * @param node node to examine
532 * @param prop_name name of property to find
533 * @param ptrp returns pointer to region, or NULL if no address
534 * @param size returns size of region
535 * @return 0 if ok, -1 on error (propery not found)
537 int fdtdec_decode_region(const void *blob, int node,
538 const char *prop_name, void **ptrp, size_t *size);
540 /* A flash map entry, containing an offset and length */
547 * Read a flash entry from the fdt
549 * @param blob FDT blob
550 * @param node Offset of node to read
551 * @param name Name of node being read
552 * @param entry Place to put offset and size of this node
553 * @return 0 if ok, -ve on error
555 int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
556 struct fmap_entry *entry);