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_TEGRA30_USB, /* Tegra30 USB port */
68 COMPAT_NVIDIA_TEGRA114_USB, /* Tegra114 USB port */
69 COMPAT_NVIDIA_TEGRA114_I2C, /* Tegra114 I2C w/single clock source */
70 COMPAT_NVIDIA_TEGRA20_I2C, /* Tegra20 i2c */
71 COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra20 dvc (really just i2c) */
72 COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */
73 COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
74 COMPAT_NVIDIA_TEGRA20_KBC, /* Tegra20 Keyboard */
75 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */
76 COMPAT_NVIDIA_TEGRA20_PWM, /* Tegra 2 PWM controller */
77 COMPAT_NVIDIA_TEGRA20_DC, /* Tegra 2 Display controller */
78 COMPAT_NVIDIA_TEGRA30_SDMMC, /* Tegra30 SDMMC controller */
79 COMPAT_NVIDIA_TEGRA20_SDMMC, /* Tegra20 SDMMC controller */
80 COMPAT_NVIDIA_TEGRA20_SFLASH, /* Tegra 2 SPI flash controller */
81 COMPAT_NVIDIA_TEGRA20_SLINK, /* Tegra 2 SPI SLINK controller */
82 COMPAT_NVIDIA_TEGRA114_SPI, /* Tegra 114 SPI controller */
83 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */
84 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */
85 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */
86 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */
87 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */
88 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */
89 COMPAT_GOOGLE_CROS_EC, /* Google CROS_EC Protocol */
90 COMPAT_GOOGLE_CROS_EC_KEYB, /* Google CROS_EC Keyboard */
91 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */
92 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */
93 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */
94 COMPAT_SAMSUNG_EXYNOS_FIMD, /* Exynos Display controller */
95 COMPAT_SAMSUNG_EXYNOS5_DP, /* Exynos Display port controller */
96 COMPAT_SAMSUNG_EXYNOS5_DWMMC, /* Exynos5 DWMMC controller */
97 COMPAT_SAMSUNG_EXYNOS_SERIAL, /* Exynos UART */
98 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */
99 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */
100 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */
101 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */
102 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */
103 COMPAT_SAMSUNG_EXYNOS5_I2C, /* Exynos5 High Speed I2C Controller */
108 /* GPIOs are numbered from 0 */
110 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
112 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
115 /* This is the state of a GPIO pin as defined by the fdt */
116 struct fdt_gpio_state {
117 const char *name; /* name of the fdt property defining this */
118 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
119 u8 flags; /* FDT_GPIO_... flags */
122 /* This tells us whether a fdt_gpio_state record is valid or not */
123 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
126 * Read the GPIO taking into account the polarity of the pin.
128 * @param gpio pointer to the decoded gpio
129 * @return value of the gpio if successful, < 0 if unsuccessful
131 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
134 * Write the GPIO taking into account the polarity of the pin.
136 * @param gpio pointer to the decoded gpio
137 * @return 0 if successful
139 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
142 * Find the next numbered alias for a peripheral. This is used to enumerate
143 * all the peripherals of a certain type.
145 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
146 * this function will return a pointer to the node the alias points to, and
147 * then update *upto to 1. Next time you call this function, the next node
150 * All nodes returned will match the compatible ID, as it is assumed that
151 * all peripherals use the same driver.
153 * @param blob FDT blob to use
154 * @param name Root name of alias to search for
155 * @param id Compatible ID to look for
156 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
158 int fdtdec_next_alias(const void *blob, const char *name,
159 enum fdt_compat_id id, int *upto);
162 * Find the compatible ID for a given node.
164 * Generally each node has at least one compatible string attached to it.
165 * This function looks through our list of known compatible strings and
166 * returns the corresponding ID which matches the compatible string.
168 * @param blob FDT blob to use
169 * @param node Node containing compatible string to find
170 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
172 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
175 * Find the next compatible node for a peripheral.
177 * Do the first call with node = 0. This function will return a pointer to
178 * the next compatible node. Next time you call this function, pass the
179 * value returned, and the next node will be provided.
181 * @param blob FDT blob to use
182 * @param node Start node for search
183 * @param id Compatible ID to look for (enum fdt_compat_id)
184 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
186 int fdtdec_next_compatible(const void *blob, int node,
187 enum fdt_compat_id id);
190 * Find the next compatible subnode for a peripheral.
192 * Do the first call with node set to the parent and depth = 0. This
193 * function will return the offset of the next compatible node. Next time
194 * you call this function, pass the node value returned last time, with
195 * depth unchanged, and the next node will be provided.
197 * @param blob FDT blob to use
198 * @param node Start node for search
199 * @param id Compatible ID to look for (enum fdt_compat_id)
200 * @param depthp Current depth (set to 0 before first call)
201 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
203 int fdtdec_next_compatible_subnode(const void *blob, int node,
204 enum fdt_compat_id id, int *depthp);
207 * Look up an address property in a node and return it as an address.
208 * The property must hold either one address with no trailing data or
209 * one address with a length. This is only tested on 32-bit machines.
211 * @param blob FDT blob
212 * @param node node to examine
213 * @param prop_name name of property to find
214 * @return address, if found, or FDT_ADDR_T_NONE if not
216 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
217 const char *prop_name);
220 * Look up an address property in a node and return it as an address.
221 * The property must hold one address with a length. This is only tested
222 * on 32-bit machines.
224 * @param blob FDT blob
225 * @param node node to examine
226 * @param prop_name name of property to find
227 * @return address, if found, or FDT_ADDR_T_NONE if not
229 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
230 const char *prop_name, fdt_size_t *sizep);
233 * Look up a 32-bit integer property in a node and return it. The property
234 * must have at least 4 bytes of data. The value of the first cell is
237 * @param blob FDT blob
238 * @param node node to examine
239 * @param prop_name name of property to find
240 * @param default_val default value to return if the property is not found
241 * @return integer value, if found, or default_val if not
243 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
247 * Look up a 64-bit integer property in a node and return it. The property
248 * must have at least 8 bytes of data (2 cells). The first two cells are
249 * concatenated to form a 8 bytes value, where the first cell is top half and
250 * the second cell is bottom half.
252 * @param blob FDT blob
253 * @param node node to examine
254 * @param prop_name name of property to find
255 * @param default_val default value to return if the property is not found
256 * @return integer value, if found, or default_val if not
258 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
259 uint64_t default_val);
262 * Checks whether a node is enabled.
263 * This looks for a 'status' property. If this exists, then returns 1 if
264 * the status is 'ok' and 0 otherwise. If there is no status property,
265 * it returns 1 on the assumption that anything mentioned should be enabled
268 * @param blob FDT blob
269 * @param node node to examine
270 * @return integer value 0 (not enabled) or 1 (enabled)
272 int fdtdec_get_is_enabled(const void *blob, int node);
275 * Make sure we have a valid fdt available to control U-Boot.
277 * If not, a message is printed to the console if the console is ready.
279 * @return 0 if all ok, -1 if not
281 int fdtdec_prepare_fdt(void);
284 * Checks that we have a valid fdt available to control U-Boot.
286 * However, if not then for the moment nothing is done, since this function
287 * is called too early to panic().
291 int fdtdec_check_fdt(void);
294 * Find the nodes for a peripheral and return a list of them in the correct
295 * order. This is used to enumerate all the peripherals of a certain type.
297 * To use this, optionally set up a /aliases node with alias properties for
298 * a peripheral. For example, for usb you could have:
301 * usb0 = "/ehci@c5008000";
302 * usb1 = "/ehci@c5000000";
305 * Pass "usb" as the name to this function and will return a list of two
306 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
308 * All nodes returned will match the compatible ID, as it is assumed that
309 * all peripherals use the same driver.
311 * If no alias node is found, then the node list will be returned in the
312 * order found in the fdt. If the aliases mention a node which doesn't
313 * exist, then this will be ignored. If nodes are found with no aliases,
314 * they will be added in any order.
316 * If there is a gap in the aliases, then this function return a 0 node at
317 * that position. The return value will also count these gaps.
319 * This function checks node properties and will not return nodes which are
320 * marked disabled (status = "disabled").
322 * @param blob FDT blob to use
323 * @param name Root name of alias to search for
324 * @param id Compatible ID to look for
325 * @param node_list Place to put list of found nodes
326 * @param maxcount Maximum number of nodes to find
327 * @return number of nodes found on success, FTD_ERR_... on error
329 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
330 enum fdt_compat_id id, int *node_list, int maxcount);
333 * This function is similar to fdtdec_find_aliases_for_id() except that it
334 * adds to the node_list that is passed in. Any 0 elements are considered
335 * available for allocation - others are considered already used and are
338 * You can use this by calling fdtdec_find_aliases_for_id() with an
339 * uninitialised array, then setting the elements that are returned to -1,
340 * say, then calling this function, perhaps with a different compat id.
341 * Any elements you get back that are >0 are new nodes added by the call
344 * Note that if you have some nodes with aliases and some without, you are
345 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
346 * one compat_id may fill in positions for which you have aliases defined
347 * for another compat_id. When you later call *this* function with the second
348 * compat_id, the alias positions may already be used. A debug warning may
349 * be generated in this case, but it is safest to define aliases for all
350 * nodes when you care about the ordering.
352 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
353 enum fdt_compat_id id, int *node_list, int maxcount);
356 * Get the name for a compatible ID
358 * @param id Compatible ID to look for
359 * @return compatible string for that id
361 const char *fdtdec_get_compatible(enum fdt_compat_id id);
363 /* Look up a phandle and follow it to its node. Then return the offset
366 * @param blob FDT blob
367 * @param node node to examine
368 * @param prop_name name of property to find
369 * @return node offset if found, -ve error code on error
371 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
374 * Look up a property in a node and return its contents in an integer
375 * array of given length. The property must have at least enough data for
376 * the array (4*count bytes). It may have more, but this will be ignored.
378 * @param blob FDT blob
379 * @param node node to examine
380 * @param prop_name name of property to find
381 * @param array array to fill with data
382 * @param count number of array elements
383 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
384 * or -FDT_ERR_BADLAYOUT if not enough data
386 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
387 u32 *array, int count);
390 * Look up a property in a node and return a pointer to its contents as a
391 * unsigned int array of given length. The property must have at least enough
392 * data for the array ('count' cells). It may have more, but this will be
393 * ignored. The data is not copied.
395 * Note that you must access elements of the array with fdt32_to_cpu(),
396 * since the elements will be big endian even on a little endian machine.
398 * @param blob FDT blob
399 * @param node node to examine
400 * @param prop_name name of property to find
401 * @param count number of array elements
402 * @return pointer to array if found, or NULL if the property is not
403 * found or there is not enough data
405 const u32 *fdtdec_locate_array(const void *blob, int node,
406 const char *prop_name, int count);
409 * Look up a boolean property in a node and return it.
411 * A boolean properly is true if present in the device tree and false if not
412 * present, regardless of its value.
414 * @param blob FDT blob
415 * @param node node to examine
416 * @param prop_name name of property to find
417 * @return 1 if the properly is present; 0 if it isn't present
419 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
422 * Decode a single GPIOs from an FDT.
424 * If the property is not found, then the GPIO structure will still be
425 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
426 * provide optional GPIOs.
428 * @param blob FDT blob to use
429 * @param node Node to look at
430 * @param prop_name Node property name
431 * @param gpio gpio elements to fill from FDT
432 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
434 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
435 struct fdt_gpio_state *gpio);
438 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
441 * @param blob FDT blob to use
442 * @param node Node to look at
443 * @param prop_name Node property name
444 * @param gpio Array of gpio elements to fill from FDT. This will be
445 * untouched if either 0 or an error is returned
446 * @param max_count Maximum number of elements allowed
447 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
448 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
450 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
451 struct fdt_gpio_state *gpio, int max_count);
454 * Set up a GPIO pin according to the provided gpio information. At present this
455 * just requests the GPIO.
457 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
458 * deal with optional GPIOs.
460 * @param gpio GPIO info to use for set up
461 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
463 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
466 * Look in the FDT for a config item with the given name and return its value
467 * as a 32-bit integer. The property must have at least 4 bytes of data. The
468 * value of the first cell is returned.
470 * @param blob FDT blob to use
471 * @param prop_name Node property name
472 * @param default_val default value to return if the property is not found
473 * @return integer value, if found, or default_val if not
475 int fdtdec_get_config_int(const void *blob, const char *prop_name,
479 * Look in the FDT for a config item with the given name
480 * and return whether it exists.
482 * @param blob FDT blob
483 * @param prop_name property name to look up
484 * @return 1, if it exists, or 0 if not
486 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
489 * Look in the FDT for a config item with the given name and return its value
492 * @param blob FDT blob
493 * @param prop_name property name to look up
494 * @returns property string, NULL on error.
496 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
499 * Look up a property in a node and return its contents in a byte
500 * array of given length. The property must have at least enough data for
501 * the array (count bytes). It may have more, but this will be ignored.
503 * @param blob FDT blob
504 * @param node node to examine
505 * @param prop_name name of property to find
506 * @param array array to fill with data
507 * @param count number of array elements
508 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
509 * or -FDT_ERR_BADLAYOUT if not enough data
511 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
512 u8 *array, int count);
515 * Look up a property in a node and return a pointer to its contents as a
516 * byte array of given length. The property must have at least enough data
517 * for the array (count bytes). It may have more, but this will be ignored.
518 * The data is not copied.
520 * @param blob FDT blob
521 * @param node node to examine
522 * @param prop_name name of property to find
523 * @param count number of array elements
524 * @return pointer to byte array if found, or NULL if the property is not
525 * found or there is not enough data
527 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
528 const char *prop_name, int count);
531 * Look up a property in a node which contains a memory region address and
532 * size. Then return a pointer to this address.
534 * The property must hold one address with a length. This is only tested on
537 * @param blob FDT blob
538 * @param node node to examine
539 * @param prop_name name of property to find
540 * @param ptrp returns pointer to region, or NULL if no address
541 * @param size returns size of region
542 * @return 0 if ok, -1 on error (propery not found)
544 int fdtdec_decode_region(const void *blob, int node,
545 const char *prop_name, void **ptrp, size_t *size);