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 #define FDT_ADDR_T_NONE (-1ULL)
42 #define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
43 #define fdt_size_to_cpu(reg) be64_to_cpu(reg)
45 typedef u32 fdt_addr_t;
46 #define FDT_ADDR_T_NONE (-1U)
47 #define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
48 #define fdt_size_to_cpu(reg) be32_to_cpu(reg)
51 /* Information obtained about memory from the FDT */
58 * Compat types that we know about and for which we might have drivers.
59 * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
64 COMPAT_NVIDIA_TEGRA20_USB, /* Tegra20 USB port */
65 COMPAT_NVIDIA_TEGRA114_I2C, /* Tegra114 I2C w/single clock source */
66 COMPAT_NVIDIA_TEGRA20_I2C, /* Tegra20 i2c */
67 COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra20 dvc (really just i2c) */
68 COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */
69 COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
70 COMPAT_NVIDIA_TEGRA20_KBC, /* Tegra20 Keyboard */
71 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */
72 COMPAT_NVIDIA_TEGRA20_PWM, /* Tegra 2 PWM controller */
73 COMPAT_NVIDIA_TEGRA20_DC, /* Tegra 2 Display controller */
74 COMPAT_NVIDIA_TEGRA30_SDMMC, /* Tegra30 SDMMC controller */
75 COMPAT_NVIDIA_TEGRA20_SDMMC, /* Tegra20 SDMMC controller */
76 COMPAT_NVIDIA_TEGRA20_SFLASH, /* Tegra 2 SPI flash controller */
77 COMPAT_NVIDIA_TEGRA20_SLINK, /* Tegra 2 SPI SLINK controller */
78 COMPAT_NVIDIA_TEGRA114_SPI, /* Tegra 114 SPI controller */
79 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */
80 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */
81 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */
82 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */
83 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */
84 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */
85 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */
86 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */
87 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */
88 COMPAT_SAMSUNG_EXYNOS_FIMD, /* Exynos Display controller */
89 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */
90 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */
95 /* GPIOs are numbered from 0 */
97 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
99 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
102 /* This is the state of a GPIO pin as defined by the fdt */
103 struct fdt_gpio_state {
104 const char *name; /* name of the fdt property defining this */
105 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
106 u8 flags; /* FDT_GPIO_... flags */
109 /* This tells us whether a fdt_gpio_state record is valid or not */
110 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
113 * Read the GPIO taking into account the polarity of the pin.
115 * @param gpio pointer to the decoded gpio
116 * @return value of the gpio if successful, < 0 if unsuccessful
118 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
121 * Write the GPIO taking into account the polarity of the pin.
123 * @param gpio pointer to the decoded gpio
124 * @return 0 if successful
126 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
129 * Find the next numbered alias for a peripheral. This is used to enumerate
130 * all the peripherals of a certain type.
132 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
133 * this function will return a pointer to the node the alias points to, and
134 * then update *upto to 1. Next time you call this function, the next node
137 * All nodes returned will match the compatible ID, as it is assumed that
138 * all peripherals use the same driver.
140 * @param blob FDT blob to use
141 * @param name Root name of alias to search for
142 * @param id Compatible ID to look for
143 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
145 int fdtdec_next_alias(const void *blob, const char *name,
146 enum fdt_compat_id id, int *upto);
149 * Find the compatible ID for a given node.
151 * Generally each node has at least one compatible string attached to it.
152 * This function looks through our list of known compatible strings and
153 * returns the corresponding ID which matches the compatible string.
155 * @param blob FDT blob to use
156 * @param node Node containing compatible string to find
157 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
159 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
162 * Find the next compatible node for a peripheral.
164 * Do the first call with node = 0. This function will return a pointer to
165 * the next compatible node. Next time you call this function, pass the
166 * value returned, and the next node will be provided.
168 * @param blob FDT blob to use
169 * @param node Start node for search
170 * @param id Compatible ID to look for (enum fdt_compat_id)
171 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
173 int fdtdec_next_compatible(const void *blob, int node,
174 enum fdt_compat_id id);
177 * Find the next compatible subnode for a peripheral.
179 * Do the first call with node set to the parent and depth = 0. This
180 * function will return the offset of the next compatible node. Next time
181 * you call this function, pass the node value returned last time, with
182 * depth unchanged, and the next node will be provided.
184 * @param blob FDT blob to use
185 * @param node Start node for search
186 * @param id Compatible ID to look for (enum fdt_compat_id)
187 * @param depthp Current depth (set to 0 before first call)
188 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
190 int fdtdec_next_compatible_subnode(const void *blob, int node,
191 enum fdt_compat_id id, int *depthp);
194 * Look up an address property in a node and return it as an address.
195 * The property must hold either one address with no trailing data or
196 * one address with a length. This is only tested on 32-bit machines.
198 * @param blob FDT blob
199 * @param node node to examine
200 * @param prop_name name of property to find
201 * @return address, if found, or FDT_ADDR_T_NONE if not
203 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
204 const char *prop_name);
207 * Look up a 32-bit integer property in a node and return it. The property
208 * must have at least 4 bytes of data. The value of the first cell is
211 * @param blob FDT blob
212 * @param node node to examine
213 * @param prop_name name of property to find
214 * @param default_val default value to return if the property is not found
215 * @return integer value, if found, or default_val if not
217 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
221 * Look up a 64-bit integer property in a node and return it. The property
222 * must have at least 8 bytes of data (2 cells). The first two cells are
223 * concatenated to form a 8 bytes value, where the first cell is top half and
224 * the second cell is bottom half.
226 * @param blob FDT blob
227 * @param node node to examine
228 * @param prop_name name of property to find
229 * @param default_val default value to return if the property is not found
230 * @return integer value, if found, or default_val if not
232 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
233 uint64_t default_val);
236 * Checks whether a node is enabled.
237 * This looks for a 'status' property. If this exists, then returns 1 if
238 * the status is 'ok' and 0 otherwise. If there is no status property,
239 * it returns 1 on the assumption that anything mentioned should be enabled
242 * @param blob FDT blob
243 * @param node node to examine
244 * @return integer value 0 (not enabled) or 1 (enabled)
246 int fdtdec_get_is_enabled(const void *blob, int node);
249 * Make sure we have a valid fdt available to control U-Boot.
251 * If not, a message is printed to the console if the console is ready.
253 * @return 0 if all ok, -1 if not
255 int fdtdec_prepare_fdt(void);
258 * Checks that we have a valid fdt available to control U-Boot.
260 * However, if not then for the moment nothing is done, since this function
261 * is called too early to panic().
265 int fdtdec_check_fdt(void);
268 * Find the nodes for a peripheral and return a list of them in the correct
269 * order. This is used to enumerate all the peripherals of a certain type.
271 * To use this, optionally set up a /aliases node with alias properties for
272 * a peripheral. For example, for usb you could have:
275 * usb0 = "/ehci@c5008000";
276 * usb1 = "/ehci@c5000000";
279 * Pass "usb" as the name to this function and will return a list of two
280 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
282 * All nodes returned will match the compatible ID, as it is assumed that
283 * all peripherals use the same driver.
285 * If no alias node is found, then the node list will be returned in the
286 * order found in the fdt. If the aliases mention a node which doesn't
287 * exist, then this will be ignored. If nodes are found with no aliases,
288 * they will be added in any order.
290 * If there is a gap in the aliases, then this function return a 0 node at
291 * that position. The return value will also count these gaps.
293 * This function checks node properties and will not return nodes which are
294 * marked disabled (status = "disabled").
296 * @param blob FDT blob to use
297 * @param name Root name of alias to search for
298 * @param id Compatible ID to look for
299 * @param node_list Place to put list of found nodes
300 * @param maxcount Maximum number of nodes to find
301 * @return number of nodes found on success, FTD_ERR_... on error
303 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
304 enum fdt_compat_id id, int *node_list, int maxcount);
307 * This function is similar to fdtdec_find_aliases_for_id() except that it
308 * adds to the node_list that is passed in. Any 0 elements are considered
309 * available for allocation - others are considered already used and are
312 * You can use this by calling fdtdec_find_aliases_for_id() with an
313 * uninitialised array, then setting the elements that are returned to -1,
314 * say, then calling this function, perhaps with a different compat id.
315 * Any elements you get back that are >0 are new nodes added by the call
318 * Note that if you have some nodes with aliases and some without, you are
319 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
320 * one compat_id may fill in positions for which you have aliases defined
321 * for another compat_id. When you later call *this* function with the second
322 * compat_id, the alias positions may already be used. A debug warning may
323 * be generated in this case, but it is safest to define aliases for all
324 * nodes when you care about the ordering.
326 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
327 enum fdt_compat_id id, int *node_list, int maxcount);
330 * Get the name for a compatible ID
332 * @param id Compatible ID to look for
333 * @return compatible string for that id
335 const char *fdtdec_get_compatible(enum fdt_compat_id id);
337 /* Look up a phandle and follow it to its node. Then return the offset
340 * @param blob FDT blob
341 * @param node node to examine
342 * @param prop_name name of property to find
343 * @return node offset if found, -ve error code on error
345 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
348 * Look up a property in a node and return its contents in an integer
349 * array of given length. The property must have at least enough data for
350 * the array (4*count bytes). It may have more, but this will be ignored.
352 * @param blob FDT blob
353 * @param node node to examine
354 * @param prop_name name of property to find
355 * @param array array to fill with data
356 * @param count number of array elements
357 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
358 * or -FDT_ERR_BADLAYOUT if not enough data
360 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
361 u32 *array, int count);
364 * Look up a property in a node and return a pointer to its contents as a
365 * unsigned int array of given length. The property must have at least enough
366 * data for the array ('count' cells). It may have more, but this will be
367 * ignored. The data is not copied.
369 * Note that you must access elements of the array with fdt32_to_cpu(),
370 * since the elements will be big endian even on a little endian machine.
372 * @param blob FDT blob
373 * @param node node to examine
374 * @param prop_name name of property to find
375 * @param count number of array elements
376 * @return pointer to array if found, or NULL if the property is not
377 * found or there is not enough data
379 const u32 *fdtdec_locate_array(const void *blob, int node,
380 const char *prop_name, int count);
383 * Look up a boolean property in a node and return it.
385 * A boolean properly is true if present in the device tree and false if not
386 * present, regardless of its value.
388 * @param blob FDT blob
389 * @param node node to examine
390 * @param prop_name name of property to find
391 * @return 1 if the properly is present; 0 if it isn't present
393 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
396 * Decode a single GPIOs from an FDT.
398 * If the property is not found, then the GPIO structure will still be
399 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
400 * provide optional GPIOs.
402 * @param blob FDT blob to use
403 * @param node Node to look at
404 * @param prop_name Node property name
405 * @param gpio gpio elements to fill from FDT
406 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
408 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
409 struct fdt_gpio_state *gpio);
412 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
415 * @param blob FDT blob to use
416 * @param node Node to look at
417 * @param prop_name Node property name
418 * @param gpio Array of gpio elements to fill from FDT. This will be
419 * untouched if either 0 or an error is returned
420 * @param max_count Maximum number of elements allowed
421 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
422 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
424 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
425 struct fdt_gpio_state *gpio, int max_count);
428 * Set up a GPIO pin according to the provided gpio information. At present this
429 * just requests the GPIO.
431 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
432 * deal with optional GPIOs.
434 * @param gpio GPIO info to use for set up
435 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
437 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
440 * Look in the FDT for a config item with the given name and return its value
441 * as a 32-bit integer. The property must have at least 4 bytes of data. The
442 * value of the first cell is returned.
444 * @param blob FDT blob to use
445 * @param prop_name Node property name
446 * @param default_val default value to return if the property is not found
447 * @return integer value, if found, or default_val if not
449 int fdtdec_get_config_int(const void *blob, const char *prop_name,
453 * Look in the FDT for a config item with the given name
454 * and return whether it exists.
456 * @param blob FDT blob
457 * @param prop_name property name to look up
458 * @return 1, if it exists, or 0 if not
460 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
463 * Look in the FDT for a config item with the given name and return its value
466 * @param blob FDT blob
467 * @param prop_name property name to look up
468 * @returns property string, NULL on error.
470 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
473 * Look up a property in a node and return its contents in a byte
474 * array of given length. The property must have at least enough data for
475 * the array (count bytes). It may have more, but this will be ignored.
477 * @param blob FDT blob
478 * @param node node to examine
479 * @param prop_name name of property to find
480 * @param array array to fill with data
481 * @param count number of array elements
482 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
483 * or -FDT_ERR_BADLAYOUT if not enough data
485 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
486 u8 *array, int count);
489 * Look up a property in a node and return a pointer to its contents as a
490 * byte array of given length. The property must have at least enough data
491 * for the array (count bytes). It may have more, but this will be ignored.
492 * The data is not copied.
494 * @param blob FDT blob
495 * @param node node to examine
496 * @param prop_name name of property to find
497 * @param count number of array elements
498 * @return pointer to byte array if found, or NULL if the property is not
499 * found or there is not enough data
501 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
502 const char *prop_name, int count);
505 * Look up a property in a node which contains a memory region address and
506 * size. Then return a pointer to this address.
508 * The property must hold one address with a length. This is only tested on
511 * @param blob FDT blob
512 * @param node node to examine
513 * @param prop_name name of property to find
514 * @param ptrp returns pointer to region, or NULL if no address
515 * @param size returns size of region
516 * @return 0 if ok, -1 on error (propery not found)
518 int fdtdec_decode_region(const void *blob, int node,
519 const char *prop_name, void **ptrp, size_t *size);