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_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */
81 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */
82 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */
83 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */
84 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */
85 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */
86 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */
87 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */
88 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */
93 /* GPIOs are numbered from 0 */
95 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
97 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
100 /* This is the state of a GPIO pin as defined by the fdt */
101 struct fdt_gpio_state {
102 const char *name; /* name of the fdt property defining this */
103 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
104 u8 flags; /* FDT_GPIO_... flags */
107 /* This tells us whether a fdt_gpio_state record is valid or not */
108 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
111 * Read the GPIO taking into account the polarity of the pin.
113 * @param gpio pointer to the decoded gpio
114 * @return value of the gpio if successful, < 0 if unsuccessful
116 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
119 * Write the GPIO taking into account the polarity of the pin.
121 * @param gpio pointer to the decoded gpio
122 * @return 0 if successful
124 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
127 * Find the next numbered alias for a peripheral. This is used to enumerate
128 * all the peripherals of a certain type.
130 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
131 * this function will return a pointer to the node the alias points to, and
132 * then update *upto to 1. Next time you call this function, the next node
135 * All nodes returned will match the compatible ID, as it is assumed that
136 * all peripherals use the same driver.
138 * @param blob FDT blob to use
139 * @param name Root name of alias to search for
140 * @param id Compatible ID to look for
141 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
143 int fdtdec_next_alias(const void *blob, const char *name,
144 enum fdt_compat_id id, int *upto);
147 * Find the compatible ID for a given node.
149 * Generally each node has at least one compatible string attached to it.
150 * This function looks through our list of known compatible strings and
151 * returns the corresponding ID which matches the compatible string.
153 * @param blob FDT blob to use
154 * @param node Node containing compatible string to find
155 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
157 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
160 * Find the next compatible node for a peripheral.
162 * Do the first call with node = 0. This function will return a pointer to
163 * the next compatible node. Next time you call this function, pass the
164 * value returned, and the next node will be provided.
166 * @param blob FDT blob to use
167 * @param node Start node for search
168 * @param id Compatible ID to look for (enum fdt_compat_id)
169 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
171 int fdtdec_next_compatible(const void *blob, int node,
172 enum fdt_compat_id id);
175 * Find the next compatible subnode for a peripheral.
177 * Do the first call with node set to the parent and depth = 0. This
178 * function will return the offset of the next compatible node. Next time
179 * you call this function, pass the node value returned last time, with
180 * depth unchanged, and the next node will be provided.
182 * @param blob FDT blob to use
183 * @param node Start node for search
184 * @param id Compatible ID to look for (enum fdt_compat_id)
185 * @param depthp Current depth (set to 0 before first call)
186 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
188 int fdtdec_next_compatible_subnode(const void *blob, int node,
189 enum fdt_compat_id id, int *depthp);
192 * Look up an address property in a node and return it as an address.
193 * The property must hold either one address with no trailing data or
194 * one address with a length. This is only tested on 32-bit machines.
196 * @param blob FDT blob
197 * @param node node to examine
198 * @param prop_name name of property to find
199 * @return address, if found, or FDT_ADDR_T_NONE if not
201 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
202 const char *prop_name);
205 * Look up an address property in a node and return it as an address.
206 * The property must hold one address with a length. This is only tested
207 * on 32-bit machines.
209 * @param blob FDT blob
210 * @param node node to examine
211 * @param prop_name name of property to find
212 * @return address, if found, or FDT_ADDR_T_NONE if not
214 fdt_addr_t fdtdec_get_addr_size(const void *blob, int node,
215 const char *prop_name, fdt_size_t *sizep);
218 * Look up a 32-bit integer property in a node and return it. The property
219 * must have at least 4 bytes of data. The value of the first cell is
222 * @param blob FDT blob
223 * @param node node to examine
224 * @param prop_name name of property to find
225 * @param default_val default value to return if the property is not found
226 * @return integer value, if found, or default_val if not
228 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
232 * Look up a 64-bit integer property in a node and return it. The property
233 * must have at least 8 bytes of data (2 cells). The first two cells are
234 * concatenated to form a 8 bytes value, where the first cell is top half and
235 * the second cell is bottom half.
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 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
244 uint64_t default_val);
247 * Checks whether a node is enabled.
248 * This looks for a 'status' property. If this exists, then returns 1 if
249 * the status is 'ok' and 0 otherwise. If there is no status property,
250 * it returns 1 on the assumption that anything mentioned should be enabled
253 * @param blob FDT blob
254 * @param node node to examine
255 * @return integer value 0 (not enabled) or 1 (enabled)
257 int fdtdec_get_is_enabled(const void *blob, int node);
260 * Make sure we have a valid fdt available to control U-Boot.
262 * If not, a message is printed to the console if the console is ready.
264 * @return 0 if all ok, -1 if not
266 int fdtdec_prepare_fdt(void);
269 * Checks that we have a valid fdt available to control U-Boot.
271 * However, if not then for the moment nothing is done, since this function
272 * is called too early to panic().
276 int fdtdec_check_fdt(void);
279 * Find the nodes for a peripheral and return a list of them in the correct
280 * order. This is used to enumerate all the peripherals of a certain type.
282 * To use this, optionally set up a /aliases node with alias properties for
283 * a peripheral. For example, for usb you could have:
286 * usb0 = "/ehci@c5008000";
287 * usb1 = "/ehci@c5000000";
290 * Pass "usb" as the name to this function and will return a list of two
291 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
293 * All nodes returned will match the compatible ID, as it is assumed that
294 * all peripherals use the same driver.
296 * If no alias node is found, then the node list will be returned in the
297 * order found in the fdt. If the aliases mention a node which doesn't
298 * exist, then this will be ignored. If nodes are found with no aliases,
299 * they will be added in any order.
301 * If there is a gap in the aliases, then this function return a 0 node at
302 * that position. The return value will also count these gaps.
304 * This function checks node properties and will not return nodes which are
305 * marked disabled (status = "disabled").
307 * @param blob FDT blob to use
308 * @param name Root name of alias to search for
309 * @param id Compatible ID to look for
310 * @param node_list Place to put list of found nodes
311 * @param maxcount Maximum number of nodes to find
312 * @return number of nodes found on success, FTD_ERR_... on error
314 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
315 enum fdt_compat_id id, int *node_list, int maxcount);
318 * This function is similar to fdtdec_find_aliases_for_id() except that it
319 * adds to the node_list that is passed in. Any 0 elements are considered
320 * available for allocation - others are considered already used and are
323 * You can use this by calling fdtdec_find_aliases_for_id() with an
324 * uninitialised array, then setting the elements that are returned to -1,
325 * say, then calling this function, perhaps with a different compat id.
326 * Any elements you get back that are >0 are new nodes added by the call
329 * Note that if you have some nodes with aliases and some without, you are
330 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
331 * one compat_id may fill in positions for which you have aliases defined
332 * for another compat_id. When you later call *this* function with the second
333 * compat_id, the alias positions may already be used. A debug warning may
334 * be generated in this case, but it is safest to define aliases for all
335 * nodes when you care about the ordering.
337 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
338 enum fdt_compat_id id, int *node_list, int maxcount);
341 * Get the name for a compatible ID
343 * @param id Compatible ID to look for
344 * @return compatible string for that id
346 const char *fdtdec_get_compatible(enum fdt_compat_id id);
348 /* Look up a phandle and follow it to its node. Then return the offset
351 * @param blob FDT blob
352 * @param node node to examine
353 * @param prop_name name of property to find
354 * @return node offset if found, -ve error code on error
356 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
359 * Look up a property in a node and return its contents in an integer
360 * array of given length. The property must have at least enough data for
361 * the array (4*count bytes). It may have more, but this will be ignored.
363 * @param blob FDT blob
364 * @param node node to examine
365 * @param prop_name name of property to find
366 * @param array array to fill with data
367 * @param count number of array elements
368 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
369 * or -FDT_ERR_BADLAYOUT if not enough data
371 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
372 u32 *array, int count);
375 * Look up a property in a node and return a pointer to its contents as a
376 * unsigned int array of given length. The property must have at least enough
377 * data for the array ('count' cells). It may have more, but this will be
378 * ignored. The data is not copied.
380 * Note that you must access elements of the array with fdt32_to_cpu(),
381 * since the elements will be big endian even on a little endian machine.
383 * @param blob FDT blob
384 * @param node node to examine
385 * @param prop_name name of property to find
386 * @param count number of array elements
387 * @return pointer to array if found, or NULL if the property is not
388 * found or there is not enough data
390 const u32 *fdtdec_locate_array(const void *blob, int node,
391 const char *prop_name, int count);
394 * Look up a boolean property in a node and return it.
396 * A boolean properly is true if present in the device tree and false if not
397 * present, regardless of its value.
399 * @param blob FDT blob
400 * @param node node to examine
401 * @param prop_name name of property to find
402 * @return 1 if the properly is present; 0 if it isn't present
404 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
407 * Decode a single GPIOs from an FDT.
409 * If the property is not found, then the GPIO structure will still be
410 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
411 * provide optional GPIOs.
413 * @param blob FDT blob to use
414 * @param node Node to look at
415 * @param prop_name Node property name
416 * @param gpio gpio elements to fill from FDT
417 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
419 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
420 struct fdt_gpio_state *gpio);
423 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
426 * @param blob FDT blob to use
427 * @param node Node to look at
428 * @param prop_name Node property name
429 * @param gpio Array of gpio elements to fill from FDT. This will be
430 * untouched if either 0 or an error is returned
431 * @param max_count Maximum number of elements allowed
432 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
433 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
435 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
436 struct fdt_gpio_state *gpio, int max_count);
439 * Set up a GPIO pin according to the provided gpio information. At present this
440 * just requests the GPIO.
442 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
443 * deal with optional GPIOs.
445 * @param gpio GPIO info to use for set up
446 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
448 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
451 * Look in the FDT for a config item with the given name and return its value
452 * as a 32-bit integer. The property must have at least 4 bytes of data. The
453 * value of the first cell is returned.
455 * @param blob FDT blob to use
456 * @param prop_name Node property name
457 * @param default_val default value to return if the property is not found
458 * @return integer value, if found, or default_val if not
460 int fdtdec_get_config_int(const void *blob, const char *prop_name,
464 * Look in the FDT for a config item with the given name
465 * and return whether it exists.
467 * @param blob FDT blob
468 * @param prop_name property name to look up
469 * @return 1, if it exists, or 0 if not
471 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
474 * Look in the FDT for a config item with the given name and return its value
477 * @param blob FDT blob
478 * @param prop_name property name to look up
479 * @returns property string, NULL on error.
481 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
484 * Look up a property in a node and return its contents in a byte
485 * array of given length. The property must have at least enough data for
486 * the array (count bytes). It may have more, but this will be ignored.
488 * @param blob FDT blob
489 * @param node node to examine
490 * @param prop_name name of property to find
491 * @param array array to fill with data
492 * @param count number of array elements
493 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
494 * or -FDT_ERR_BADLAYOUT if not enough data
496 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
497 u8 *array, int count);
500 * Look up a property in a node and return a pointer to its contents as a
501 * byte array of given length. The property must have at least enough data
502 * for the array (count bytes). It may have more, but this will be ignored.
503 * The data is not copied.
505 * @param blob FDT blob
506 * @param node node to examine
507 * @param prop_name name of property to find
508 * @param count number of array elements
509 * @return pointer to byte array if found, or NULL if the property is not
510 * found or there is not enough data
512 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
513 const char *prop_name, int count);
516 * Look up a property in a node which contains a memory region address and
517 * size. Then return a pointer to this address.
519 * The property must hold one address with a length. This is only tested on
522 * @param blob FDT blob
523 * @param node node to examine
524 * @param prop_name name of property to find
525 * @param ptrp returns pointer to region, or NULL if no address
526 * @param size returns size of region
527 * @return 0 if ok, -1 on error (propery not found)
529 int fdtdec_decode_region(const void *blob, int node,
530 const char *prop_name, void **ptrp, size_t *size);