2 * Copyright (c) 2011 The Chromium OS Authors.
3 * See file CREDITS for list of people who contributed to this
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation; either version 2 of
9 * the License, or (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
26 * This file contains convenience functions for decoding useful and
27 * enlightening information from FDTs. It is intended to be used by device
28 * drivers and board-specific code within U-Boot. It aims to reduce the
29 * amount of FDT munging required within U-Boot itself, so that driver code
30 * changes to support FDT are minimized.
36 * A typedef for a physical address. Note that fdt data is always big
37 * endian even on a litle endian machine.
39 #ifdef CONFIG_PHYS_64BIT
40 typedef u64 fdt_addr_t;
41 typedef u64 fdt_size_t;
42 #define FDT_ADDR_T_NONE (-1ULL)
43 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
44 #define fdt_size_to_cpu(reg) be64_to_cpu(reg)
46 typedef u32 fdt_addr_t;
47 typedef u32 fdt_size_t;
48 #define FDT_ADDR_T_NONE (-1U)
49 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
50 #define fdt_size_to_cpu(reg) be32_to_cpu(reg)
53 /* Information obtained about memory from the FDT */
60 * Compat types that we know about and for which we might have drivers.
61 * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
66 COMPAT_NVIDIA_TEGRA20_USB, /* Tegra20 USB port */
67 COMPAT_NVIDIA_TEGRA114_I2C, /* Tegra114 I2C w/single clock source */
68 COMPAT_NVIDIA_TEGRA20_I2C, /* Tegra20 i2c */
69 COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra20 dvc (really just i2c) */
70 COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */
71 COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
72 COMPAT_NVIDIA_TEGRA20_KBC, /* Tegra20 Keyboard */
73 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */
74 COMPAT_NVIDIA_TEGRA20_PWM, /* Tegra 2 PWM controller */
75 COMPAT_NVIDIA_TEGRA20_DC, /* Tegra 2 Display controller */
76 COMPAT_NVIDIA_TEGRA30_SDMMC, /* Tegra30 SDMMC controller */
77 COMPAT_NVIDIA_TEGRA20_SDMMC, /* Tegra20 SDMMC controller */
78 COMPAT_NVIDIA_TEGRA20_SFLASH, /* Tegra 2 SPI flash controller */
79 COMPAT_NVIDIA_TEGRA20_SLINK, /* Tegra 2 SPI SLINK controller */
80 COMPAT_NVIDIA_TEGRA114_SPI, /* Tegra 114 SPI controller */
81 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */
82 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */
83 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */
84 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */
85 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */
86 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */
87 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */
88 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */
89 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */
90 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */
91 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */
92 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */
93 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */
98 /* GPIOs are numbered from 0 */
100 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
102 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
105 /* This is the state of a GPIO pin as defined by the fdt */
106 struct fdt_gpio_state {
107 const char *name; /* name of the fdt property defining this */
108 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
109 u8 flags; /* FDT_GPIO_... flags */
112 /* This tells us whether a fdt_gpio_state record is valid or not */
113 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
116 * Read the GPIO taking into account the polarity of the pin.
118 * @param gpio pointer to the decoded gpio
119 * @return value of the gpio if successful, < 0 if unsuccessful
121 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
124 * Write the GPIO taking into account the polarity of the pin.
126 * @param gpio pointer to the decoded gpio
127 * @return 0 if successful
129 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
132 * Find the next numbered alias for a peripheral. This is used to enumerate
133 * all the peripherals of a certain type.
135 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
136 * this function will return a pointer to the node the alias points to, and
137 * then update *upto to 1. Next time you call this function, the next node
140 * All nodes returned will match the compatible ID, as it is assumed that
141 * all peripherals use the same driver.
143 * @param blob FDT blob to use
144 * @param name Root name of alias to search for
145 * @param id Compatible ID to look for
146 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
148 int fdtdec_next_alias(const void *blob, const char *name,
149 enum fdt_compat_id id, int *upto);
152 * Find the compatible ID for a given node.
154 * Generally each node has at least one compatible string attached to it.
155 * This function looks through our list of known compatible strings and
156 * returns the corresponding ID which matches the compatible string.
158 * @param blob FDT blob to use
159 * @param node Node containing compatible string to find
160 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
162 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
165 * Find the next compatible node for a peripheral.
167 * Do the first call with node = 0. This function will return a pointer to
168 * the next compatible node. Next time you call this function, pass the
169 * value returned, and the next node will be provided.
171 * @param blob FDT blob to use
172 * @param node Start node for search
173 * @param id Compatible ID to look for (enum fdt_compat_id)
174 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
176 int fdtdec_next_compatible(const void *blob, int node,
177 enum fdt_compat_id id);
180 * Find the next compatible subnode for a peripheral.
182 * Do the first call with node set to the parent and depth = 0. This
183 * function will return the offset of the next compatible node. Next time
184 * you call this function, pass the node value returned last time, with
185 * depth unchanged, and the next node will be provided.
187 * @param blob FDT blob to use
188 * @param node Start node for search
189 * @param id Compatible ID to look for (enum fdt_compat_id)
190 * @param depthp Current depth (set to 0 before first call)
191 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
193 int fdtdec_next_compatible_subnode(const void *blob, int node,
194 enum fdt_compat_id id, int *depthp);
197 * Look up an address property in a node and return it as an address.
198 * The property must hold either one address with no trailing data or
199 * one address with a length. This is only tested on 32-bit machines.
201 * @param blob FDT blob
202 * @param node node to examine
203 * @param prop_name name of property to find
204 * @return address, if found, or FDT_ADDR_T_NONE if not
206 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
207 const char *prop_name);
210 * Look up an address property in a node and return it as an address.
211 * The property must hold one address with a length. This is only tested
212 * on 32-bit machines.
214 * @param blob FDT blob
215 * @param node node to examine
216 * @param prop_name name of property to find
217 * @return address, if found, or FDT_ADDR_T_NONE if not
219 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
220 const char *prop_name, fdt_size_t *sizep);
223 * Look up a 32-bit integer property in a node and return it. The property
224 * must have at least 4 bytes of data. The value of the first cell is
227 * @param blob FDT blob
228 * @param node node to examine
229 * @param prop_name name of property to find
230 * @param default_val default value to return if the property is not found
231 * @return integer value, if found, or default_val if not
233 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
237 * Look up a 64-bit integer property in a node and return it. The property
238 * must have at least 8 bytes of data (2 cells). The first two cells are
239 * concatenated to form a 8 bytes value, where the first cell is top half and
240 * the second cell is bottom half.
242 * @param blob FDT blob
243 * @param node node to examine
244 * @param prop_name name of property to find
245 * @param default_val default value to return if the property is not found
246 * @return integer value, if found, or default_val if not
248 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
249 uint64_t default_val);
252 * Checks whether a node is enabled.
253 * This looks for a 'status' property. If this exists, then returns 1 if
254 * the status is 'ok' and 0 otherwise. If there is no status property,
255 * it returns 1 on the assumption that anything mentioned should be enabled
258 * @param blob FDT blob
259 * @param node node to examine
260 * @return integer value 0 (not enabled) or 1 (enabled)
262 int fdtdec_get_is_enabled(const void *blob, int node);
265 * Make sure we have a valid fdt available to control U-Boot.
267 * If not, a message is printed to the console if the console is ready.
269 * @return 0 if all ok, -1 if not
271 int fdtdec_prepare_fdt(void);
274 * Checks that we have a valid fdt available to control U-Boot.
276 * However, if not then for the moment nothing is done, since this function
277 * is called too early to panic().
281 int fdtdec_check_fdt(void);
284 * Find the nodes for a peripheral and return a list of them in the correct
285 * order. This is used to enumerate all the peripherals of a certain type.
287 * To use this, optionally set up a /aliases node with alias properties for
288 * a peripheral. For example, for usb you could have:
291 * usb0 = "/ehci@c5008000";
292 * usb1 = "/ehci@c5000000";
295 * Pass "usb" as the name to this function and will return a list of two
296 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
298 * All nodes returned will match the compatible ID, as it is assumed that
299 * all peripherals use the same driver.
301 * If no alias node is found, then the node list will be returned in the
302 * order found in the fdt. If the aliases mention a node which doesn't
303 * exist, then this will be ignored. If nodes are found with no aliases,
304 * they will be added in any order.
306 * If there is a gap in the aliases, then this function return a 0 node at
307 * that position. The return value will also count these gaps.
309 * This function checks node properties and will not return nodes which are
310 * marked disabled (status = "disabled").
312 * @param blob FDT blob to use
313 * @param name Root name of alias to search for
314 * @param id Compatible ID to look for
315 * @param node_list Place to put list of found nodes
316 * @param maxcount Maximum number of nodes to find
317 * @return number of nodes found on success, FTD_ERR_... on error
319 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
320 enum fdt_compat_id id, int *node_list, int maxcount);
323 * This function is similar to fdtdec_find_aliases_for_id() except that it
324 * adds to the node_list that is passed in. Any 0 elements are considered
325 * available for allocation - others are considered already used and are
328 * You can use this by calling fdtdec_find_aliases_for_id() with an
329 * uninitialised array, then setting the elements that are returned to -1,
330 * say, then calling this function, perhaps with a different compat id.
331 * Any elements you get back that are >0 are new nodes added by the call
334 * Note that if you have some nodes with aliases and some without, you are
335 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
336 * one compat_id may fill in positions for which you have aliases defined
337 * for another compat_id. When you later call *this* function with the second
338 * compat_id, the alias positions may already be used. A debug warning may
339 * be generated in this case, but it is safest to define aliases for all
340 * nodes when you care about the ordering.
342 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
343 enum fdt_compat_id id, int *node_list, int maxcount);
346 * Get the name for a compatible ID
348 * @param id Compatible ID to look for
349 * @return compatible string for that id
351 const char *fdtdec_get_compatible(enum fdt_compat_id id);
353 /* Look up a phandle and follow it to its node. Then return the offset
356 * @param blob FDT blob
357 * @param node node to examine
358 * @param prop_name name of property to find
359 * @return node offset if found, -ve error code on error
361 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
364 * Look up a property in a node and return its contents in an integer
365 * array of given length. The property must have at least enough data for
366 * the array (4*count bytes). It may have more, but this will be ignored.
368 * @param blob FDT blob
369 * @param node node to examine
370 * @param prop_name name of property to find
371 * @param array array to fill with data
372 * @param count number of array elements
373 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
374 * or -FDT_ERR_BADLAYOUT if not enough data
376 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
377 u32 *array, int count);
380 * Look up a property in a node and return a pointer to its contents as a
381 * unsigned int array of given length. The property must have at least enough
382 * data for the array ('count' cells). It may have more, but this will be
383 * ignored. The data is not copied.
385 * Note that you must access elements of the array with fdt32_to_cpu(),
386 * since the elements will be big endian even on a little endian machine.
388 * @param blob FDT blob
389 * @param node node to examine
390 * @param prop_name name of property to find
391 * @param count number of array elements
392 * @return pointer to array if found, or NULL if the property is not
393 * found or there is not enough data
395 const u32 *fdtdec_locate_array(const void *blob, int node,
396 const char *prop_name, int count);
399 * Look up a boolean property in a node and return it.
401 * A boolean properly is true if present in the device tree and false if not
402 * present, regardless of its value.
404 * @param blob FDT blob
405 * @param node node to examine
406 * @param prop_name name of property to find
407 * @return 1 if the properly is present; 0 if it isn't present
409 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
412 * Decode a single GPIOs from an FDT.
414 * If the property is not found, then the GPIO structure will still be
415 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
416 * provide optional GPIOs.
418 * @param blob FDT blob to use
419 * @param node Node to look at
420 * @param prop_name Node property name
421 * @param gpio gpio elements to fill from FDT
422 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
424 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
425 struct fdt_gpio_state *gpio);
428 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
431 * @param blob FDT blob to use
432 * @param node Node to look at
433 * @param prop_name Node property name
434 * @param gpio Array of gpio elements to fill from FDT. This will be
435 * untouched if either 0 or an error is returned
436 * @param max_count Maximum number of elements allowed
437 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
438 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
440 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
441 struct fdt_gpio_state *gpio, int max_count);
444 * Set up a GPIO pin according to the provided gpio information. At present this
445 * just requests the GPIO.
447 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
448 * deal with optional GPIOs.
450 * @param gpio GPIO info to use for set up
451 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
453 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
456 * Look in the FDT for a config item with the given name and return its value
457 * as a 32-bit integer. The property must have at least 4 bytes of data. The
458 * value of the first cell is returned.
460 * @param blob FDT blob to use
461 * @param prop_name Node property name
462 * @param default_val default value to return if the property is not found
463 * @return integer value, if found, or default_val if not
465 int fdtdec_get_config_int(const void *blob, const char *prop_name,
469 * Look in the FDT for a config item with the given name
470 * and return whether it exists.
472 * @param blob FDT blob
473 * @param prop_name property name to look up
474 * @return 1, if it exists, or 0 if not
476 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
479 * Look in the FDT for a config item with the given name and return its value
482 * @param blob FDT blob
483 * @param prop_name property name to look up
484 * @returns property string, NULL on error.
486 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
489 * Look up a property in a node and return its contents in a byte
490 * array of given length. The property must have at least enough data for
491 * the array (count bytes). It may have more, but this will be ignored.
493 * @param blob FDT blob
494 * @param node node to examine
495 * @param prop_name name of property to find
496 * @param array array to fill with data
497 * @param count number of array elements
498 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
499 * or -FDT_ERR_BADLAYOUT if not enough data
501 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
502 u8 *array, int count);
505 * Look up a property in a node and return a pointer to its contents as a
506 * byte array of given length. The property must have at least enough data
507 * for the array (count bytes). It may have more, but this will be ignored.
508 * The data is not copied.
510 * @param blob FDT blob
511 * @param node node to examine
512 * @param prop_name name of property to find
513 * @param count number of array elements
514 * @return pointer to byte array if found, or NULL if the property is not
515 * found or there is not enough data
517 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
518 const char *prop_name, int count);
521 * Look up a property in a node which contains a memory region address and
522 * size. Then return a pointer to this address.
524 * The property must hold one address with a length. This is only tested on
527 * @param blob FDT blob
528 * @param node node to examine
529 * @param prop_name name of property to find
530 * @param ptrp returns pointer to region, or NULL if no address
531 * @param size returns size of region
532 * @return 0 if ok, -1 on error (propery not found)
534 int fdtdec_decode_region(const void *blob, int node,
535 const char *prop_name, void **ptrp, size_t *size);