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_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */
89 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */
94 /* GPIOs are numbered from 0 */
96 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
98 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
101 /* This is the state of a GPIO pin as defined by the fdt */
102 struct fdt_gpio_state {
103 const char *name; /* name of the fdt property defining this */
104 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
105 u8 flags; /* FDT_GPIO_... flags */
108 /* This tells us whether a fdt_gpio_state record is valid or not */
109 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
112 * Read the GPIO taking into account the polarity of the pin.
114 * @param gpio pointer to the decoded gpio
115 * @return value of the gpio if successful, < 0 if unsuccessful
117 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
120 * Write the GPIO taking into account the polarity of the pin.
122 * @param gpio pointer to the decoded gpio
123 * @return 0 if successful
125 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
128 * Find the next numbered alias for a peripheral. This is used to enumerate
129 * all the peripherals of a certain type.
131 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
132 * this function will return a pointer to the node the alias points to, and
133 * then update *upto to 1. Next time you call this function, the next node
136 * All nodes returned will match the compatible ID, as it is assumed that
137 * all peripherals use the same driver.
139 * @param blob FDT blob to use
140 * @param name Root name of alias to search for
141 * @param id Compatible ID to look for
142 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
144 int fdtdec_next_alias(const void *blob, const char *name,
145 enum fdt_compat_id id, int *upto);
148 * Find the compatible ID for a given node.
150 * Generally each node has at least one compatible string attached to it.
151 * This function looks through our list of known compatible strings and
152 * returns the corresponding ID which matches the compatible string.
154 * @param blob FDT blob to use
155 * @param node Node containing compatible string to find
156 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
158 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
161 * Find the next compatible node for a peripheral.
163 * Do the first call with node = 0. This function will return a pointer to
164 * the next compatible node. Next time you call this function, pass the
165 * value returned, and the next node will be provided.
167 * @param blob FDT blob to use
168 * @param node Start node for search
169 * @param id Compatible ID to look for (enum fdt_compat_id)
170 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
172 int fdtdec_next_compatible(const void *blob, int node,
173 enum fdt_compat_id id);
176 * Find the next compatible subnode for a peripheral.
178 * Do the first call with node set to the parent and depth = 0. This
179 * function will return the offset of the next compatible node. Next time
180 * you call this function, pass the node value returned last time, with
181 * depth unchanged, and the next node will be provided.
183 * @param blob FDT blob to use
184 * @param node Start node for search
185 * @param id Compatible ID to look for (enum fdt_compat_id)
186 * @param depthp Current depth (set to 0 before first call)
187 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
189 int fdtdec_next_compatible_subnode(const void *blob, int node,
190 enum fdt_compat_id id, int *depthp);
193 * Look up an address property in a node and return it as an address.
194 * The property must hold either one address with no trailing data or
195 * one address with a length. This is only tested on 32-bit machines.
197 * @param blob FDT blob
198 * @param node node to examine
199 * @param prop_name name of property to find
200 * @return address, if found, or FDT_ADDR_T_NONE if not
202 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
203 const char *prop_name);
206 * Look up a 32-bit integer property in a node and return it. The property
207 * must have at least 4 bytes of data. The value of the first cell is
210 * @param blob FDT blob
211 * @param node node to examine
212 * @param prop_name name of property to find
213 * @param default_val default value to return if the property is not found
214 * @return integer value, if found, or default_val if not
216 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
220 * Look up a 64-bit integer property in a node and return it. The property
221 * must have at least 8 bytes of data (2 cells). The first two cells are
222 * concatenated to form a 8 bytes value, where the first cell is top half and
223 * the second cell is bottom half.
225 * @param blob FDT blob
226 * @param node node to examine
227 * @param prop_name name of property to find
228 * @param default_val default value to return if the property is not found
229 * @return integer value, if found, or default_val if not
231 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
232 uint64_t default_val);
235 * Checks whether a node is enabled.
236 * This looks for a 'status' property. If this exists, then returns 1 if
237 * the status is 'ok' and 0 otherwise. If there is no status property,
238 * it returns 1 on the assumption that anything mentioned should be enabled
241 * @param blob FDT blob
242 * @param node node to examine
243 * @return integer value 0 (not enabled) or 1 (enabled)
245 int fdtdec_get_is_enabled(const void *blob, int node);
248 * Make sure we have a valid fdt available to control U-Boot.
250 * If not, a message is printed to the console if the console is ready.
252 * @return 0 if all ok, -1 if not
254 int fdtdec_prepare_fdt(void);
257 * Checks that we have a valid fdt available to control U-Boot.
259 * However, if not then for the moment nothing is done, since this function
260 * is called too early to panic().
264 int fdtdec_check_fdt(void);
267 * Find the nodes for a peripheral and return a list of them in the correct
268 * order. This is used to enumerate all the peripherals of a certain type.
270 * To use this, optionally set up a /aliases node with alias properties for
271 * a peripheral. For example, for usb you could have:
274 * usb0 = "/ehci@c5008000";
275 * usb1 = "/ehci@c5000000";
278 * Pass "usb" as the name to this function and will return a list of two
279 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
281 * All nodes returned will match the compatible ID, as it is assumed that
282 * all peripherals use the same driver.
284 * If no alias node is found, then the node list will be returned in the
285 * order found in the fdt. If the aliases mention a node which doesn't
286 * exist, then this will be ignored. If nodes are found with no aliases,
287 * they will be added in any order.
289 * If there is a gap in the aliases, then this function return a 0 node at
290 * that position. The return value will also count these gaps.
292 * This function checks node properties and will not return nodes which are
293 * marked disabled (status = "disabled").
295 * @param blob FDT blob to use
296 * @param name Root name of alias to search for
297 * @param id Compatible ID to look for
298 * @param node_list Place to put list of found nodes
299 * @param maxcount Maximum number of nodes to find
300 * @return number of nodes found on success, FTD_ERR_... on error
302 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
303 enum fdt_compat_id id, int *node_list, int maxcount);
306 * This function is similar to fdtdec_find_aliases_for_id() except that it
307 * adds to the node_list that is passed in. Any 0 elements are considered
308 * available for allocation - others are considered already used and are
311 * You can use this by calling fdtdec_find_aliases_for_id() with an
312 * uninitialised array, then setting the elements that are returned to -1,
313 * say, then calling this function, perhaps with a different compat id.
314 * Any elements you get back that are >0 are new nodes added by the call
317 * Note that if you have some nodes with aliases and some without, you are
318 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
319 * one compat_id may fill in positions for which you have aliases defined
320 * for another compat_id. When you later call *this* function with the second
321 * compat_id, the alias positions may already be used. A debug warning may
322 * be generated in this case, but it is safest to define aliases for all
323 * nodes when you care about the ordering.
325 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
326 enum fdt_compat_id id, int *node_list, int maxcount);
329 * Get the name for a compatible ID
331 * @param id Compatible ID to look for
332 * @return compatible string for that id
334 const char *fdtdec_get_compatible(enum fdt_compat_id id);
336 /* Look up a phandle and follow it to its node. Then return the offset
339 * @param blob FDT blob
340 * @param node node to examine
341 * @param prop_name name of property to find
342 * @return node offset if found, -ve error code on error
344 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
347 * Look up a property in a node and return its contents in an integer
348 * array of given length. The property must have at least enough data for
349 * the array (4*count bytes). It may have more, but this will be ignored.
351 * @param blob FDT blob
352 * @param node node to examine
353 * @param prop_name name of property to find
354 * @param array array to fill with data
355 * @param count number of array elements
356 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
357 * or -FDT_ERR_BADLAYOUT if not enough data
359 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
360 u32 *array, int count);
363 * Look up a property in a node and return a pointer to its contents as a
364 * unsigned int array of given length. The property must have at least enough
365 * data for the array ('count' cells). It may have more, but this will be
366 * ignored. The data is not copied.
368 * Note that you must access elements of the array with fdt32_to_cpu(),
369 * since the elements will be big endian even on a little endian machine.
371 * @param blob FDT blob
372 * @param node node to examine
373 * @param prop_name name of property to find
374 * @param count number of array elements
375 * @return pointer to array if found, or NULL if the property is not
376 * found or there is not enough data
378 const u32 *fdtdec_locate_array(const void *blob, int node,
379 const char *prop_name, int count);
382 * Look up a boolean property in a node and return it.
384 * A boolean properly is true if present in the device tree and false if not
385 * present, regardless of its value.
387 * @param blob FDT blob
388 * @param node node to examine
389 * @param prop_name name of property to find
390 * @return 1 if the properly is present; 0 if it isn't present
392 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
395 * Decode a single GPIOs from an FDT.
397 * If the property is not found, then the GPIO structure will still be
398 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
399 * provide optional GPIOs.
401 * @param blob FDT blob to use
402 * @param node Node to look at
403 * @param prop_name Node property name
404 * @param gpio gpio elements to fill from FDT
405 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
407 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
408 struct fdt_gpio_state *gpio);
411 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
414 * @param blob FDT blob to use
415 * @param node Node to look at
416 * @param prop_name Node property name
417 * @param gpio Array of gpio elements to fill from FDT. This will be
418 * untouched if either 0 or an error is returned
419 * @param max_count Maximum number of elements allowed
420 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
421 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
423 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
424 struct fdt_gpio_state *gpio, int max_count);
427 * Set up a GPIO pin according to the provided gpio information. At present this
428 * just requests the GPIO.
430 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
431 * deal with optional GPIOs.
433 * @param gpio GPIO info to use for set up
434 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
436 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
439 * Look in the FDT for a config item with the given name and return its value
440 * as a 32-bit integer. The property must have at least 4 bytes of data. The
441 * value of the first cell is returned.
443 * @param blob FDT blob to use
444 * @param prop_name Node property name
445 * @param default_val default value to return if the property is not found
446 * @return integer value, if found, or default_val if not
448 int fdtdec_get_config_int(const void *blob, const char *prop_name,
452 * Look in the FDT for a config item with the given name
453 * and return whether it exists.
455 * @param blob FDT blob
456 * @param prop_name property name to look up
457 * @return 1, if it exists, or 0 if not
459 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
462 * Look in the FDT for a config item with the given name and return its value
465 * @param blob FDT blob
466 * @param prop_name property name to look up
467 * @returns property string, NULL on error.
469 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
472 * Look up a property in a node and return its contents in a byte
473 * array of given length. The property must have at least enough data for
474 * the array (count bytes). It may have more, but this will be ignored.
476 * @param blob FDT blob
477 * @param node node to examine
478 * @param prop_name name of property to find
479 * @param array array to fill with data
480 * @param count number of array elements
481 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
482 * or -FDT_ERR_BADLAYOUT if not enough data
484 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
485 u8 *array, int count);
488 * Look up a property in a node and return a pointer to its contents as a
489 * byte array of given length. The property must have at least enough data
490 * for the array (count bytes). It may have more, but this will be ignored.
491 * The data is not copied.
493 * @param blob FDT blob
494 * @param node node to examine
495 * @param prop_name name of property to find
496 * @param count number of array elements
497 * @return pointer to byte array if found, or NULL if the property is not
498 * found or there is not enough data
500 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
501 const char *prop_name, int count);
504 * Look up a property in a node which contains a memory region address and
505 * size. Then return a pointer to this address.
507 * The property must hold one address with a length. This is only tested on
510 * @param blob FDT blob
511 * @param node node to examine
512 * @param prop_name name of property to find
513 * @param ptrp returns pointer to region, or NULL if no address
514 * @param size returns size of region
515 * @return 0 if ok, -1 on error (propery not found)
517 int fdtdec_decode_region(const void *blob, int node,
518 const char *prop_name, void **ptrp, size_t *size);