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_GOOGLE_CROS_EC_KEYB, /* Google CROS_EC Keyboard */
89 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */
90 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */
91 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */
92 COMPAT_SAMSUNG_EXYNOS_FIMD, /* Exynos Display controller */
93 COMPAT_SAMSUNG_EXYNOS5_DP, /* Exynos Display port controller */
94 COMPAT_SAMSUNG_EXYNOS5_DWMMC, /* Exynos5 DWMMC controller */
95 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */
96 COMPAT_GENERIC_SPI_FLASH, /* Generic SPI Flash chip */
97 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */
98 COMPAT_INFINEON_SLB9635_TPM, /* Infineon SLB9635 TPM */
99 COMPAT_INFINEON_SLB9645_TPM, /* Infineon SLB9645 TPM */
104 /* GPIOs are numbered from 0 */
106 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
108 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
111 /* This is the state of a GPIO pin as defined by the fdt */
112 struct fdt_gpio_state {
113 const char *name; /* name of the fdt property defining this */
114 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
115 u8 flags; /* FDT_GPIO_... flags */
118 /* This tells us whether a fdt_gpio_state record is valid or not */
119 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
122 * Read the GPIO taking into account the polarity of the pin.
124 * @param gpio pointer to the decoded gpio
125 * @return value of the gpio if successful, < 0 if unsuccessful
127 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
130 * Write the GPIO taking into account the polarity of the pin.
132 * @param gpio pointer to the decoded gpio
133 * @return 0 if successful
135 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
138 * Find the next numbered alias for a peripheral. This is used to enumerate
139 * all the peripherals of a certain type.
141 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
142 * this function will return a pointer to the node the alias points to, and
143 * then update *upto to 1. Next time you call this function, the next node
146 * All nodes returned will match the compatible ID, as it is assumed that
147 * all peripherals use the same driver.
149 * @param blob FDT blob to use
150 * @param name Root name of alias to search for
151 * @param id Compatible ID to look for
152 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
154 int fdtdec_next_alias(const void *blob, const char *name,
155 enum fdt_compat_id id, int *upto);
158 * Find the compatible ID for a given node.
160 * Generally each node has at least one compatible string attached to it.
161 * This function looks through our list of known compatible strings and
162 * returns the corresponding ID which matches the compatible string.
164 * @param blob FDT blob to use
165 * @param node Node containing compatible string to find
166 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
168 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
171 * Find the next compatible node for a peripheral.
173 * Do the first call with node = 0. This function will return a pointer to
174 * the next compatible node. Next time you call this function, pass the
175 * value returned, and the next node will be provided.
177 * @param blob FDT blob to use
178 * @param node Start node for search
179 * @param id Compatible ID to look for (enum fdt_compat_id)
180 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
182 int fdtdec_next_compatible(const void *blob, int node,
183 enum fdt_compat_id id);
186 * Find the next compatible subnode for a peripheral.
188 * Do the first call with node set to the parent and depth = 0. This
189 * function will return the offset of the next compatible node. Next time
190 * you call this function, pass the node value returned last time, with
191 * depth unchanged, and the next node will be provided.
193 * @param blob FDT blob to use
194 * @param node Start node for search
195 * @param id Compatible ID to look for (enum fdt_compat_id)
196 * @param depthp Current depth (set to 0 before first call)
197 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
199 int fdtdec_next_compatible_subnode(const void *blob, int node,
200 enum fdt_compat_id id, int *depthp);
203 * Look up an address property in a node and return it as an address.
204 * The property must hold either one address with no trailing data or
205 * one address with a length. This is only tested on 32-bit machines.
207 * @param blob FDT blob
208 * @param node node to examine
209 * @param prop_name name of property to find
210 * @return address, if found, or FDT_ADDR_T_NONE if not
212 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
213 const char *prop_name);
216 * Look up an address property in a node and return it as an address.
217 * The property must hold one address with a length. This is only tested
218 * on 32-bit machines.
220 * @param blob FDT blob
221 * @param node node to examine
222 * @param prop_name name of property to find
223 * @return address, if found, or FDT_ADDR_T_NONE if not
225 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
226 const char *prop_name, fdt_size_t *sizep);
229 * Look up a 32-bit integer property in a node and return it. The property
230 * must have at least 4 bytes of data. The value of the first cell is
233 * @param blob FDT blob
234 * @param node node to examine
235 * @param prop_name name of property to find
236 * @param default_val default value to return if the property is not found
237 * @return integer value, if found, or default_val if not
239 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
243 * Look up a 64-bit integer property in a node and return it. The property
244 * must have at least 8 bytes of data (2 cells). The first two cells are
245 * concatenated to form a 8 bytes value, where the first cell is top half and
246 * the second cell is bottom half.
248 * @param blob FDT blob
249 * @param node node to examine
250 * @param prop_name name of property to find
251 * @param default_val default value to return if the property is not found
252 * @return integer value, if found, or default_val if not
254 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
255 uint64_t default_val);
258 * Checks whether a node is enabled.
259 * This looks for a 'status' property. If this exists, then returns 1 if
260 * the status is 'ok' and 0 otherwise. If there is no status property,
261 * it returns 1 on the assumption that anything mentioned should be enabled
264 * @param blob FDT blob
265 * @param node node to examine
266 * @return integer value 0 (not enabled) or 1 (enabled)
268 int fdtdec_get_is_enabled(const void *blob, int node);
271 * Make sure we have a valid fdt available to control U-Boot.
273 * If not, a message is printed to the console if the console is ready.
275 * @return 0 if all ok, -1 if not
277 int fdtdec_prepare_fdt(void);
280 * Checks that we have a valid fdt available to control U-Boot.
282 * However, if not then for the moment nothing is done, since this function
283 * is called too early to panic().
287 int fdtdec_check_fdt(void);
290 * Find the nodes for a peripheral and return a list of them in the correct
291 * order. This is used to enumerate all the peripherals of a certain type.
293 * To use this, optionally set up a /aliases node with alias properties for
294 * a peripheral. For example, for usb you could have:
297 * usb0 = "/ehci@c5008000";
298 * usb1 = "/ehci@c5000000";
301 * Pass "usb" as the name to this function and will return a list of two
302 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
304 * All nodes returned will match the compatible ID, as it is assumed that
305 * all peripherals use the same driver.
307 * If no alias node is found, then the node list will be returned in the
308 * order found in the fdt. If the aliases mention a node which doesn't
309 * exist, then this will be ignored. If nodes are found with no aliases,
310 * they will be added in any order.
312 * If there is a gap in the aliases, then this function return a 0 node at
313 * that position. The return value will also count these gaps.
315 * This function checks node properties and will not return nodes which are
316 * marked disabled (status = "disabled").
318 * @param blob FDT blob to use
319 * @param name Root name of alias to search for
320 * @param id Compatible ID to look for
321 * @param node_list Place to put list of found nodes
322 * @param maxcount Maximum number of nodes to find
323 * @return number of nodes found on success, FTD_ERR_... on error
325 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
326 enum fdt_compat_id id, int *node_list, int maxcount);
329 * This function is similar to fdtdec_find_aliases_for_id() except that it
330 * adds to the node_list that is passed in. Any 0 elements are considered
331 * available for allocation - others are considered already used and are
334 * You can use this by calling fdtdec_find_aliases_for_id() with an
335 * uninitialised array, then setting the elements that are returned to -1,
336 * say, then calling this function, perhaps with a different compat id.
337 * Any elements you get back that are >0 are new nodes added by the call
340 * Note that if you have some nodes with aliases and some without, you are
341 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
342 * one compat_id may fill in positions for which you have aliases defined
343 * for another compat_id. When you later call *this* function with the second
344 * compat_id, the alias positions may already be used. A debug warning may
345 * be generated in this case, but it is safest to define aliases for all
346 * nodes when you care about the ordering.
348 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
349 enum fdt_compat_id id, int *node_list, int maxcount);
352 * Get the name for a compatible ID
354 * @param id Compatible ID to look for
355 * @return compatible string for that id
357 const char *fdtdec_get_compatible(enum fdt_compat_id id);
359 /* Look up a phandle and follow it to its node. Then return the offset
362 * @param blob FDT blob
363 * @param node node to examine
364 * @param prop_name name of property to find
365 * @return node offset if found, -ve error code on error
367 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
370 * Look up a property in a node and return its contents in an integer
371 * array of given length. The property must have at least enough data for
372 * the array (4*count bytes). It may have more, but this will be ignored.
374 * @param blob FDT blob
375 * @param node node to examine
376 * @param prop_name name of property to find
377 * @param array array to fill with data
378 * @param count number of array elements
379 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
380 * or -FDT_ERR_BADLAYOUT if not enough data
382 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
383 u32 *array, int count);
386 * Look up a property in a node and return a pointer to its contents as a
387 * unsigned int array of given length. The property must have at least enough
388 * data for the array ('count' cells). It may have more, but this will be
389 * ignored. The data is not copied.
391 * Note that you must access elements of the array with fdt32_to_cpu(),
392 * since the elements will be big endian even on a little endian machine.
394 * @param blob FDT blob
395 * @param node node to examine
396 * @param prop_name name of property to find
397 * @param count number of array elements
398 * @return pointer to array if found, or NULL if the property is not
399 * found or there is not enough data
401 const u32 *fdtdec_locate_array(const void *blob, int node,
402 const char *prop_name, int count);
405 * Look up a boolean property in a node and return it.
407 * A boolean properly is true if present in the device tree and false if not
408 * present, regardless of its value.
410 * @param blob FDT blob
411 * @param node node to examine
412 * @param prop_name name of property to find
413 * @return 1 if the properly is present; 0 if it isn't present
415 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
418 * Decode a single GPIOs from an FDT.
420 * If the property is not found, then the GPIO structure will still be
421 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
422 * provide optional GPIOs.
424 * @param blob FDT blob to use
425 * @param node Node to look at
426 * @param prop_name Node property name
427 * @param gpio gpio elements to fill from FDT
428 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
430 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
431 struct fdt_gpio_state *gpio);
434 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
437 * @param blob FDT blob to use
438 * @param node Node to look at
439 * @param prop_name Node property name
440 * @param gpio Array of gpio elements to fill from FDT. This will be
441 * untouched if either 0 or an error is returned
442 * @param max_count Maximum number of elements allowed
443 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
444 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
446 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
447 struct fdt_gpio_state *gpio, int max_count);
450 * Set up a GPIO pin according to the provided gpio information. At present this
451 * just requests the GPIO.
453 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
454 * deal with optional GPIOs.
456 * @param gpio GPIO info to use for set up
457 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
459 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
462 * Look in the FDT for a config item with the given name and return its value
463 * as a 32-bit integer. The property must have at least 4 bytes of data. The
464 * value of the first cell is returned.
466 * @param blob FDT blob to use
467 * @param prop_name Node property name
468 * @param default_val default value to return if the property is not found
469 * @return integer value, if found, or default_val if not
471 int fdtdec_get_config_int(const void *blob, const char *prop_name,
475 * Look in the FDT for a config item with the given name
476 * and return whether it exists.
478 * @param blob FDT blob
479 * @param prop_name property name to look up
480 * @return 1, if it exists, or 0 if not
482 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
485 * Look in the FDT for a config item with the given name and return its value
488 * @param blob FDT blob
489 * @param prop_name property name to look up
490 * @returns property string, NULL on error.
492 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
495 * Look up a property in a node and return its contents in a byte
496 * array of given length. The property must have at least enough data for
497 * the array (count bytes). It may have more, but this will be ignored.
499 * @param blob FDT blob
500 * @param node node to examine
501 * @param prop_name name of property to find
502 * @param array array to fill with data
503 * @param count number of array elements
504 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
505 * or -FDT_ERR_BADLAYOUT if not enough data
507 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
508 u8 *array, int count);
511 * Look up a property in a node and return a pointer to its contents as a
512 * byte array of given length. The property must have at least enough data
513 * for the array (count bytes). It may have more, but this will be ignored.
514 * The data is not copied.
516 * @param blob FDT blob
517 * @param node node to examine
518 * @param prop_name name of property to find
519 * @param count number of array elements
520 * @return pointer to byte array if found, or NULL if the property is not
521 * found or there is not enough data
523 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
524 const char *prop_name, int count);
527 * Look up a property in a node which contains a memory region address and
528 * size. Then return a pointer to this address.
530 * The property must hold one address with a length. This is only tested on
533 * @param blob FDT blob
534 * @param node node to examine
535 * @param prop_name name of property to find
536 * @param ptrp returns pointer to region, or NULL if no address
537 * @param size returns size of region
538 * @return 0 if ok, -1 on error (propery not found)
540 int fdtdec_decode_region(const void *blob, int node,
541 const char *prop_name, void **ptrp, size_t *size);