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_TEGRA20_I2C, /* Tegra20 i2c */
66 COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra20 dvc (really just i2c) */
67 COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra20 memory controller */
68 COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
69 COMPAT_NVIDIA_TEGRA20_KBC, /* Tegra20 Keyboard */
70 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */
71 COMPAT_NVIDIA_TEGRA20_PWM, /* Tegra 2 PWM controller */
72 COMPAT_NVIDIA_TEGRA20_DC, /* Tegra 2 Display controller */
73 COMPAT_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */
74 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */
75 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */
76 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */
77 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */
78 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */
79 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */
80 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */
81 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */
86 /* GPIOs are numbered from 0 */
88 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
90 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
93 /* This is the state of a GPIO pin as defined by the fdt */
94 struct fdt_gpio_state {
95 const char *name; /* name of the fdt property defining this */
96 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
97 u8 flags; /* FDT_GPIO_... flags */
100 /* This tells us whether a fdt_gpio_state record is valid or not */
101 #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
104 * Read the GPIO taking into account the polarity of the pin.
106 * @param gpio pointer to the decoded gpio
107 * @return value of the gpio if successful, < 0 if unsuccessful
109 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
112 * Write the GPIO taking into account the polarity of the pin.
114 * @param gpio pointer to the decoded gpio
115 * @return 0 if successful
117 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
120 * Find the next numbered alias for a peripheral. This is used to enumerate
121 * all the peripherals of a certain type.
123 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
124 * this function will return a pointer to the node the alias points to, and
125 * then update *upto to 1. Next time you call this function, the next node
128 * All nodes returned will match the compatible ID, as it is assumed that
129 * all peripherals use the same driver.
131 * @param blob FDT blob to use
132 * @param name Root name of alias to search for
133 * @param id Compatible ID to look for
134 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
136 int fdtdec_next_alias(const void *blob, const char *name,
137 enum fdt_compat_id id, int *upto);
140 * Find the compatible ID for a given node.
142 * Generally each node has at least one compatible string attached to it.
143 * This function looks through our list of known compatible strings and
144 * returns the corresponding ID which matches the compatible string.
146 * @param blob FDT blob to use
147 * @param node Node containing compatible string to find
148 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
150 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
153 * Find the next compatible node for a peripheral.
155 * Do the first call with node = 0. This function will return a pointer to
156 * the next compatible node. Next time you call this function, pass the
157 * value returned, and the next node will be provided.
159 * @param blob FDT blob to use
160 * @param node Start node for search
161 * @param id Compatible ID to look for (enum fdt_compat_id)
162 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
164 int fdtdec_next_compatible(const void *blob, int node,
165 enum fdt_compat_id id);
168 * Find the next compatible subnode for a peripheral.
170 * Do the first call with node set to the parent and depth = 0. This
171 * function will return the offset of the next compatible node. Next time
172 * you call this function, pass the node value returned last time, with
173 * depth unchanged, and the next node will be provided.
175 * @param blob FDT blob to use
176 * @param node Start node for search
177 * @param id Compatible ID to look for (enum fdt_compat_id)
178 * @param depthp Current depth (set to 0 before first call)
179 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
181 int fdtdec_next_compatible_subnode(const void *blob, int node,
182 enum fdt_compat_id id, int *depthp);
185 * Look up an address property in a node and return it as an address.
186 * The property must hold either one address with no trailing data or
187 * one address with a length. This is only tested on 32-bit machines.
189 * @param blob FDT blob
190 * @param node node to examine
191 * @param prop_name name of property to find
192 * @return address, if found, or FDT_ADDR_T_NONE if not
194 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
195 const char *prop_name);
198 * Look up a 32-bit integer property in a node and return it. The property
199 * must have at least 4 bytes of data. The value of the first cell is
202 * @param blob FDT blob
203 * @param node node to examine
204 * @param prop_name name of property to find
205 * @param default_val default value to return if the property is not found
206 * @return integer value, if found, or default_val if not
208 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
212 * Look up a 64-bit integer property in a node and return it. The property
213 * must have at least 8 bytes of data (2 cells). The first two cells are
214 * concatenated to form a 8 bytes value, where the first cell is top half and
215 * the second cell is bottom half.
217 * @param blob FDT blob
218 * @param node node to examine
219 * @param prop_name name of property to find
220 * @param default_val default value to return if the property is not found
221 * @return integer value, if found, or default_val if not
223 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
224 uint64_t default_val);
227 * Checks whether a node is enabled.
228 * This looks for a 'status' property. If this exists, then returns 1 if
229 * the status is 'ok' and 0 otherwise. If there is no status property,
230 * it returns 1 on the assumption that anything mentioned should be enabled
233 * @param blob FDT blob
234 * @param node node to examine
235 * @return integer value 0 (not enabled) or 1 (enabled)
237 int fdtdec_get_is_enabled(const void *blob, int node);
240 * Make sure we have a valid fdt available to control U-Boot.
242 * If not, a message is printed to the console if the console is ready.
244 * @return 0 if all ok, -1 if not
246 int fdtdec_prepare_fdt(void);
249 * Checks that we have a valid fdt available to control U-Boot.
251 * However, if not then for the moment nothing is done, since this function
252 * is called too early to panic().
256 int fdtdec_check_fdt(void);
259 * Find the nodes for a peripheral and return a list of them in the correct
260 * order. This is used to enumerate all the peripherals of a certain type.
262 * To use this, optionally set up a /aliases node with alias properties for
263 * a peripheral. For example, for usb you could have:
266 * usb0 = "/ehci@c5008000";
267 * usb1 = "/ehci@c5000000";
270 * Pass "usb" as the name to this function and will return a list of two
271 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
273 * All nodes returned will match the compatible ID, as it is assumed that
274 * all peripherals use the same driver.
276 * If no alias node is found, then the node list will be returned in the
277 * order found in the fdt. If the aliases mention a node which doesn't
278 * exist, then this will be ignored. If nodes are found with no aliases,
279 * they will be added in any order.
281 * If there is a gap in the aliases, then this function return a 0 node at
282 * that position. The return value will also count these gaps.
284 * This function checks node properties and will not return nodes which are
285 * marked disabled (status = "disabled").
287 * @param blob FDT blob to use
288 * @param name Root name of alias to search for
289 * @param id Compatible ID to look for
290 * @param node_list Place to put list of found nodes
291 * @param maxcount Maximum number of nodes to find
292 * @return number of nodes found on success, FTD_ERR_... on error
294 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
295 enum fdt_compat_id id, int *node_list, int maxcount);
298 * This function is similar to fdtdec_find_aliases_for_id() except that it
299 * adds to the node_list that is passed in. Any 0 elements are considered
300 * available for allocation - others are considered already used and are
303 * You can use this by calling fdtdec_find_aliases_for_id() with an
304 * uninitialised array, then setting the elements that are returned to -1,
305 * say, then calling this function, perhaps with a different compat id.
306 * Any elements you get back that are >0 are new nodes added by the call
309 * Note that if you have some nodes with aliases and some without, you are
310 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
311 * one compat_id may fill in positions for which you have aliases defined
312 * for another compat_id. When you later call *this* function with the second
313 * compat_id, the alias positions may already be used. A debug warning may
314 * be generated in this case, but it is safest to define aliases for all
315 * nodes when you care about the ordering.
317 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
318 enum fdt_compat_id id, int *node_list, int maxcount);
321 * Get the name for a compatible ID
323 * @param id Compatible ID to look for
324 * @return compatible string for that id
326 const char *fdtdec_get_compatible(enum fdt_compat_id id);
328 /* Look up a phandle and follow it to its node. Then return the offset
331 * @param blob FDT blob
332 * @param node node to examine
333 * @param prop_name name of property to find
334 * @return node offset if found, -ve error code on error
336 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
339 * Look up a property in a node and return its contents in an integer
340 * array of given length. The property must have at least enough data for
341 * the array (4*count bytes). It may have more, but this will be ignored.
343 * @param blob FDT blob
344 * @param node node to examine
345 * @param prop_name name of property to find
346 * @param array array to fill with data
347 * @param count number of array elements
348 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
349 * or -FDT_ERR_BADLAYOUT if not enough data
351 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
352 u32 *array, int count);
355 * Look up a property in a node and return a pointer to its contents as a
356 * unsigned int array of given length. The property must have at least enough
357 * data for the array ('count' cells). It may have more, but this will be
358 * ignored. The data is not copied.
360 * Note that you must access elements of the array with fdt32_to_cpu(),
361 * since the elements will be big endian even on a little endian machine.
363 * @param blob FDT blob
364 * @param node node to examine
365 * @param prop_name name of property to find
366 * @param count number of array elements
367 * @return pointer to array if found, or NULL if the property is not
368 * found or there is not enough data
370 const u32 *fdtdec_locate_array(const void *blob, int node,
371 const char *prop_name, int count);
374 * Look up a boolean property in a node and return it.
376 * A boolean properly is true if present in the device tree and false if not
377 * present, regardless of its value.
379 * @param blob FDT blob
380 * @param node node to examine
381 * @param prop_name name of property to find
382 * @return 1 if the properly is present; 0 if it isn't present
384 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
387 * Decode a single GPIOs from an FDT.
389 * If the property is not found, then the GPIO structure will still be
390 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
391 * provide optional GPIOs.
393 * @param blob FDT blob to use
394 * @param node Node to look at
395 * @param prop_name Node property name
396 * @param gpio gpio elements to fill from FDT
397 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
399 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
400 struct fdt_gpio_state *gpio);
403 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
406 * @param blob FDT blob to use
407 * @param node Node to look at
408 * @param prop_name Node property name
409 * @param gpio Array of gpio elements to fill from FDT. This will be
410 * untouched if either 0 or an error is returned
411 * @param max_count Maximum number of elements allowed
412 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
413 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
415 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
416 struct fdt_gpio_state *gpio, int max_count);
419 * Set up a GPIO pin according to the provided gpio information. At present this
420 * just requests the GPIO.
422 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
423 * deal with optional GPIOs.
425 * @param gpio GPIO info to use for set up
426 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
428 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
431 * Look in the FDT for a config item with the given name and return its value
432 * as a 32-bit integer. The property must have at least 4 bytes of data. The
433 * value of the first cell is returned.
435 * @param blob FDT blob to use
436 * @param prop_name Node property name
437 * @param default_val default value to return if the property is not found
438 * @return integer value, if found, or default_val if not
440 int fdtdec_get_config_int(const void *blob, const char *prop_name,
444 * Look in the FDT for a config item with the given name
445 * and return whether it exists.
447 * @param blob FDT blob
448 * @param prop_name property name to look up
449 * @return 1, if it exists, or 0 if not
451 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
454 * Look in the FDT for a config item with the given name and return its value
457 * @param blob FDT blob
458 * @param prop_name property name to look up
459 * @returns property string, NULL on error.
461 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
464 * Look up a property in a node and return its contents in a byte
465 * array of given length. The property must have at least enough data for
466 * the array (count bytes). It may have more, but this will be ignored.
468 * @param blob FDT blob
469 * @param node node to examine
470 * @param prop_name name of property to find
471 * @param array array to fill with data
472 * @param count number of array elements
473 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
474 * or -FDT_ERR_BADLAYOUT if not enough data
476 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
477 u8 *array, int count);
480 * Look up a property in a node and return a pointer to its contents as a
481 * byte array of given length. The property must have at least enough data
482 * for the array (count bytes). It may have more, but this will be ignored.
483 * The data is not copied.
485 * @param blob FDT blob
486 * @param node node to examine
487 * @param prop_name name of property to find
488 * @param count number of array elements
489 * @return pointer to byte array if found, or NULL if the property is not
490 * found or there is not enough data
492 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
493 const char *prop_name, int count);
496 * Look up a property in a node which contains a memory region address and
497 * size. Then return a pointer to this address.
499 * The property must hold one address with a length. This is only tested on
502 * @param blob FDT blob
503 * @param node node to examine
504 * @param prop_name name of property to find
505 * @param ptrp returns pointer to region, or NULL if no address
506 * @param size returns size of region
507 * @return 0 if ok, -1 on error (propery not found)
509 int fdtdec_decode_region(const void *blob, int node,
510 const char *prop_name, void **ptrp, size_t *size);