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_GOOGLE_CROS_EC, /* Google CROS_EC Protocol */
88 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */
89 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */
90 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */
91 COMPAT_SAMSUNG_EXYNOS_FIMD, /* Exynos Display controller */
92 COMPAT_SAMSUNG_EXYNOS5_DP, /* Exynos Display port controller */
93 COMPAT_SAMSUNG_EXYNOS5_DWMMC, /* Exynos5 DWMMC controller */
94 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */
95 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */
96 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */
97 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */
98 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */
103 /* GPIOs are numbered from 0 */
105 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
107 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
110 /* This is the state of a GPIO pin as defined by the fdt */
111 struct fdt_gpio_state {
112 const char *name; /* name of the fdt property defining this */
113 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
114 u8 flags; /* FDT_GPIO_... flags */
117 /* This tells us whether a fdt_gpio_state record is valid or not */
118 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
121 * Read the GPIO taking into account the polarity of the pin.
123 * @param gpio pointer to the decoded gpio
124 * @return value of the gpio if successful, < 0 if unsuccessful
126 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
129 * Write the GPIO taking into account the polarity of the pin.
131 * @param gpio pointer to the decoded gpio
132 * @return 0 if successful
134 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
137 * Find the next numbered alias for a peripheral. This is used to enumerate
138 * all the peripherals of a certain type.
140 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
141 * this function will return a pointer to the node the alias points to, and
142 * then update *upto to 1. Next time you call this function, the next node
145 * All nodes returned will match the compatible ID, as it is assumed that
146 * all peripherals use the same driver.
148 * @param blob FDT blob to use
149 * @param name Root name of alias to search for
150 * @param id Compatible ID to look for
151 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
153 int fdtdec_next_alias(const void *blob, const char *name,
154 enum fdt_compat_id id, int *upto);
157 * Find the compatible ID for a given node.
159 * Generally each node has at least one compatible string attached to it.
160 * This function looks through our list of known compatible strings and
161 * returns the corresponding ID which matches the compatible string.
163 * @param blob FDT blob to use
164 * @param node Node containing compatible string to find
165 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
167 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
170 * Find the next compatible node for a peripheral.
172 * Do the first call with node = 0. This function will return a pointer to
173 * the next compatible node. Next time you call this function, pass the
174 * value returned, and the next node will be provided.
176 * @param blob FDT blob to use
177 * @param node Start node for search
178 * @param id Compatible ID to look for (enum fdt_compat_id)
179 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
181 int fdtdec_next_compatible(const void *blob, int node,
182 enum fdt_compat_id id);
185 * Find the next compatible subnode for a peripheral.
187 * Do the first call with node set to the parent and depth = 0. This
188 * function will return the offset of the next compatible node. Next time
189 * you call this function, pass the node value returned last time, with
190 * depth unchanged, and the next node will be provided.
192 * @param blob FDT blob to use
193 * @param node Start node for search
194 * @param id Compatible ID to look for (enum fdt_compat_id)
195 * @param depthp Current depth (set to 0 before first call)
196 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
198 int fdtdec_next_compatible_subnode(const void *blob, int node,
199 enum fdt_compat_id id, int *depthp);
202 * Look up an address property in a node and return it as an address.
203 * The property must hold either one address with no trailing data or
204 * one address with a length. This is only tested on 32-bit machines.
206 * @param blob FDT blob
207 * @param node node to examine
208 * @param prop_name name of property to find
209 * @return address, if found, or FDT_ADDR_T_NONE if not
211 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
212 const char *prop_name);
215 * Look up an address property in a node and return it as an address.
216 * The property must hold one address with a length. This is only tested
217 * on 32-bit machines.
219 * @param blob FDT blob
220 * @param node node to examine
221 * @param prop_name name of property to find
222 * @return address, if found, or FDT_ADDR_T_NONE if not
224 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
225 const char *prop_name, fdt_size_t *sizep);
228 * Look up a 32-bit integer property in a node and return it. The property
229 * must have at least 4 bytes of data. The value of the first cell is
232 * @param blob FDT blob
233 * @param node node to examine
234 * @param prop_name name of property to find
235 * @param default_val default value to return if the property is not found
236 * @return integer value, if found, or default_val if not
238 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
242 * Look up a 64-bit integer property in a node and return it. The property
243 * must have at least 8 bytes of data (2 cells). The first two cells are
244 * concatenated to form a 8 bytes value, where the first cell is top half and
245 * the second cell is bottom half.
247 * @param blob FDT blob
248 * @param node node to examine
249 * @param prop_name name of property to find
250 * @param default_val default value to return if the property is not found
251 * @return integer value, if found, or default_val if not
253 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
254 uint64_t default_val);
257 * Checks whether a node is enabled.
258 * This looks for a 'status' property. If this exists, then returns 1 if
259 * the status is 'ok' and 0 otherwise. If there is no status property,
260 * it returns 1 on the assumption that anything mentioned should be enabled
263 * @param blob FDT blob
264 * @param node node to examine
265 * @return integer value 0 (not enabled) or 1 (enabled)
267 int fdtdec_get_is_enabled(const void *blob, int node);
270 * Make sure we have a valid fdt available to control U-Boot.
272 * If not, a message is printed to the console if the console is ready.
274 * @return 0 if all ok, -1 if not
276 int fdtdec_prepare_fdt(void);
279 * Checks that we have a valid fdt available to control U-Boot.
281 * However, if not then for the moment nothing is done, since this function
282 * is called too early to panic().
286 int fdtdec_check_fdt(void);
289 * Find the nodes for a peripheral and return a list of them in the correct
290 * order. This is used to enumerate all the peripherals of a certain type.
292 * To use this, optionally set up a /aliases node with alias properties for
293 * a peripheral. For example, for usb you could have:
296 * usb0 = "/ehci@c5008000";
297 * usb1 = "/ehci@c5000000";
300 * Pass "usb" as the name to this function and will return a list of two
301 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
303 * All nodes returned will match the compatible ID, as it is assumed that
304 * all peripherals use the same driver.
306 * If no alias node is found, then the node list will be returned in the
307 * order found in the fdt. If the aliases mention a node which doesn't
308 * exist, then this will be ignored. If nodes are found with no aliases,
309 * they will be added in any order.
311 * If there is a gap in the aliases, then this function return a 0 node at
312 * that position. The return value will also count these gaps.
314 * This function checks node properties and will not return nodes which are
315 * marked disabled (status = "disabled").
317 * @param blob FDT blob to use
318 * @param name Root name of alias to search for
319 * @param id Compatible ID to look for
320 * @param node_list Place to put list of found nodes
321 * @param maxcount Maximum number of nodes to find
322 * @return number of nodes found on success, FTD_ERR_... on error
324 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
325 enum fdt_compat_id id, int *node_list, int maxcount);
328 * This function is similar to fdtdec_find_aliases_for_id() except that it
329 * adds to the node_list that is passed in. Any 0 elements are considered
330 * available for allocation - others are considered already used and are
333 * You can use this by calling fdtdec_find_aliases_for_id() with an
334 * uninitialised array, then setting the elements that are returned to -1,
335 * say, then calling this function, perhaps with a different compat id.
336 * Any elements you get back that are >0 are new nodes added by the call
339 * Note that if you have some nodes with aliases and some without, you are
340 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
341 * one compat_id may fill in positions for which you have aliases defined
342 * for another compat_id. When you later call *this* function with the second
343 * compat_id, the alias positions may already be used. A debug warning may
344 * be generated in this case, but it is safest to define aliases for all
345 * nodes when you care about the ordering.
347 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
348 enum fdt_compat_id id, int *node_list, int maxcount);
351 * Get the name for a compatible ID
353 * @param id Compatible ID to look for
354 * @return compatible string for that id
356 const char *fdtdec_get_compatible(enum fdt_compat_id id);
358 /* Look up a phandle and follow it to its node. Then return the offset
361 * @param blob FDT blob
362 * @param node node to examine
363 * @param prop_name name of property to find
364 * @return node offset if found, -ve error code on error
366 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
369 * Look up a property in a node and return its contents in an integer
370 * array of given length. The property must have at least enough data for
371 * the array (4*count bytes). It may have more, but this will be ignored.
373 * @param blob FDT blob
374 * @param node node to examine
375 * @param prop_name name of property to find
376 * @param array array to fill with data
377 * @param count number of array elements
378 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
379 * or -FDT_ERR_BADLAYOUT if not enough data
381 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
382 u32 *array, int count);
385 * Look up a property in a node and return a pointer to its contents as a
386 * unsigned int array of given length. The property must have at least enough
387 * data for the array ('count' cells). It may have more, but this will be
388 * ignored. The data is not copied.
390 * Note that you must access elements of the array with fdt32_to_cpu(),
391 * since the elements will be big endian even on a little endian machine.
393 * @param blob FDT blob
394 * @param node node to examine
395 * @param prop_name name of property to find
396 * @param count number of array elements
397 * @return pointer to array if found, or NULL if the property is not
398 * found or there is not enough data
400 const u32 *fdtdec_locate_array(const void *blob, int node,
401 const char *prop_name, int count);
404 * Look up a boolean property in a node and return it.
406 * A boolean properly is true if present in the device tree and false if not
407 * present, regardless of its value.
409 * @param blob FDT blob
410 * @param node node to examine
411 * @param prop_name name of property to find
412 * @return 1 if the properly is present; 0 if it isn't present
414 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
417 * Decode a single GPIOs from an FDT.
419 * If the property is not found, then the GPIO structure will still be
420 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
421 * provide optional GPIOs.
423 * @param blob FDT blob to use
424 * @param node Node to look at
425 * @param prop_name Node property name
426 * @param gpio gpio elements to fill from FDT
427 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
429 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
430 struct fdt_gpio_state *gpio);
433 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
436 * @param blob FDT blob to use
437 * @param node Node to look at
438 * @param prop_name Node property name
439 * @param gpio Array of gpio elements to fill from FDT. This will be
440 * untouched if either 0 or an error is returned
441 * @param max_count Maximum number of elements allowed
442 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
443 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
445 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
446 struct fdt_gpio_state *gpio, int max_count);
449 * Set up a GPIO pin according to the provided gpio information. At present this
450 * just requests the GPIO.
452 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
453 * deal with optional GPIOs.
455 * @param gpio GPIO info to use for set up
456 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
458 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
461 * Look in the FDT for a config item with the given name and return its value
462 * as a 32-bit integer. The property must have at least 4 bytes of data. The
463 * value of the first cell is returned.
465 * @param blob FDT blob to use
466 * @param prop_name Node property name
467 * @param default_val default value to return if the property is not found
468 * @return integer value, if found, or default_val if not
470 int fdtdec_get_config_int(const void *blob, const char *prop_name,
474 * Look in the FDT for a config item with the given name
475 * and return whether it exists.
477 * @param blob FDT blob
478 * @param prop_name property name to look up
479 * @return 1, if it exists, or 0 if not
481 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
484 * Look in the FDT for a config item with the given name and return its value
487 * @param blob FDT blob
488 * @param prop_name property name to look up
489 * @returns property string, NULL on error.
491 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
494 * Look up a property in a node and return its contents in a byte
495 * array of given length. The property must have at least enough data for
496 * the array (count bytes). It may have more, but this will be ignored.
498 * @param blob FDT blob
499 * @param node node to examine
500 * @param prop_name name of property to find
501 * @param array array to fill with data
502 * @param count number of array elements
503 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
504 * or -FDT_ERR_BADLAYOUT if not enough data
506 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
507 u8 *array, int count);
510 * Look up a property in a node and return a pointer to its contents as a
511 * byte array of given length. The property must have at least enough data
512 * for the array (count bytes). It may have more, but this will be ignored.
513 * The data is not copied.
515 * @param blob FDT blob
516 * @param node node to examine
517 * @param prop_name name of property to find
518 * @param count number of array elements
519 * @return pointer to byte array if found, or NULL if the property is not
520 * found or there is not enough data
522 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
523 const char *prop_name, int count);
526 * Look up a property in a node which contains a memory region address and
527 * size. Then return a pointer to this address.
529 * The property must hold one address with a length. This is only tested on
532 * @param blob FDT blob
533 * @param node node to examine
534 * @param prop_name name of property to find
535 * @param ptrp returns pointer to region, or NULL if no address
536 * @param size returns size of region
537 * @return 0 if ok, -1 on error (propery not found)
539 int fdtdec_decode_region(const void *blob, int node,
540 const char *prop_name, void **ptrp, size_t *size);