1 /*
2 * Copyright (c) 2011 The Chromium OS Authors.
3 * See file CREDITS for list of people who contributed to this
4 * project.
5 *
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.
10 *
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.
15 *
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,
19 * MA 02111-1307 USA
20 */
22 #ifndef __fdtdec_h
23 #define __fdtdec_h
25 /*
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.
31 */
33 #include <libfdt.h>
35 /*
36 * A typedef for a physical address. Note that fdt data is always big
37 * endian even on a litle endian machine.
38 */
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)
44 #else
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)
49 #endif
51 /* Information obtained about memory from the FDT */
52 struct fdt_memory {
53 fdt_addr_t start;
54 fdt_addr_t end;
55 };
57 /**
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
60 * within drivers.
61 */
62 enum fdt_compat_id {
63 COMPAT_UNKNOWN,
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_SMSC_LAN9215, /* SMSC 10/100 Ethernet LAN9215 */
79 COMPAT_SAMSUNG_EXYNOS5_SROMC, /* Exynos5 SROMC */
80 COMPAT_SAMSUNG_S3C2440_I2C, /* Exynos I2C Controller */
81 COMPAT_SAMSUNG_EXYNOS5_SOUND, /* Exynos Sound */
82 COMPAT_WOLFSON_WM8994_CODEC, /* Wolfson WM8994 Sound Codec */
83 COMPAT_SAMSUNG_EXYNOS_SPI, /* Exynos SPI */
84 COMPAT_SAMSUNG_EXYNOS_EHCI, /* Exynos EHCI controller */
85 COMPAT_SAMSUNG_EXYNOS_USB_PHY, /* Exynos phy controller for usb2.0 */
86 COMPAT_SAMSUNG_EXYNOS_TMU, /* Exynos TMU */
87 COMPAT_MAXIM_MAX77686_PMIC, /* MAX77686 PMIC */
88 COMPAT_MAXIM_98095_CODEC, /* MAX98095 Codec */
90 COMPAT_COUNT,
91 };
93 /* GPIOs are numbered from 0 */
94 enum {
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) */
98 };
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 */
105 };
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)
110 /**
111 * Read the GPIO taking into account the polarity of the pin.
112 *
113 * @param gpio pointer to the decoded gpio
114 * @return value of the gpio if successful, < 0 if unsuccessful
115 */
116 int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
118 /**
119 * Write the GPIO taking into account the polarity of the pin.
120 *
121 * @param gpio pointer to the decoded gpio
122 * @return 0 if successful
123 */
124 int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
126 /**
127 * Find the next numbered alias for a peripheral. This is used to enumerate
128 * all the peripherals of a certain type.
129 *
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
133 * will be returned.
134 *
135 * All nodes returned will match the compatible ID, as it is assumed that
136 * all peripherals use the same driver.
137 *
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
142 */
143 int fdtdec_next_alias(const void *blob, const char *name,
144 enum fdt_compat_id id, int *upto);
146 /**
147 * Find the compatible ID for a given node.
148 *
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.
152 *
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
156 */
157 enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
159 /**
160 * Find the next compatible node for a peripheral.
161 *
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.
165 *
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
170 */
171 int fdtdec_next_compatible(const void *blob, int node,
172 enum fdt_compat_id id);
174 /**
175 * Find the next compatible subnode for a peripheral.
176 *
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.
181 *
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
187 */
188 int fdtdec_next_compatible_subnode(const void *blob, int node,
189 enum fdt_compat_id id, int *depthp);
191 /**
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.
195 *
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
200 */
201 fdt_addr_t fdtdec_get_addr(const void *blob, int node,
202 const char *prop_name);
204 /**
205 * Look up a 32-bit integer property in a node and return it. The property
206 * must have at least 4 bytes of data. The value of the first cell is
207 * returned.
208 *
209 * @param blob FDT blob
210 * @param node node to examine
211 * @param prop_name name of property to find
212 * @param default_val default value to return if the property is not found
213 * @return integer value, if found, or default_val if not
214 */
215 s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
216 s32 default_val);
218 /**
219 * Look up a 64-bit integer property in a node and return it. The property
220 * must have at least 8 bytes of data (2 cells). The first two cells are
221 * concatenated to form a 8 bytes value, where the first cell is top half and
222 * the second cell is bottom half.
223 *
224 * @param blob FDT blob
225 * @param node node to examine
226 * @param prop_name name of property to find
227 * @param default_val default value to return if the property is not found
228 * @return integer value, if found, or default_val if not
229 */
230 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
231 uint64_t default_val);
233 /**
234 * Checks whether a node is enabled.
235 * This looks for a 'status' property. If this exists, then returns 1 if
236 * the status is 'ok' and 0 otherwise. If there is no status property,
237 * it returns 1 on the assumption that anything mentioned should be enabled
238 * by default.
239 *
240 * @param blob FDT blob
241 * @param node node to examine
242 * @return integer value 0 (not enabled) or 1 (enabled)
243 */
244 int fdtdec_get_is_enabled(const void *blob, int node);
246 /**
247 * Make sure we have a valid fdt available to control U-Boot.
248 *
249 * If not, a message is printed to the console if the console is ready.
250 *
251 * @return 0 if all ok, -1 if not
252 */
253 int fdtdec_prepare_fdt(void);
255 /**
256 * Checks that we have a valid fdt available to control U-Boot.
258 * However, if not then for the moment nothing is done, since this function
259 * is called too early to panic().
260 *
261 * @returns 0
262 */
263 int fdtdec_check_fdt(void);
265 /**
266 * Find the nodes for a peripheral and return a list of them in the correct
267 * order. This is used to enumerate all the peripherals of a certain type.
268 *
269 * To use this, optionally set up a /aliases node with alias properties for
270 * a peripheral. For example, for usb you could have:
271 *
272 * aliases {
273 * usb0 = "/ehci@c5008000";
274 * usb1 = "/ehci@c5000000";
275 * };
276 *
277 * Pass "usb" as the name to this function and will return a list of two
278 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
279 *
280 * All nodes returned will match the compatible ID, as it is assumed that
281 * all peripherals use the same driver.
282 *
283 * If no alias node is found, then the node list will be returned in the
284 * order found in the fdt. If the aliases mention a node which doesn't
285 * exist, then this will be ignored. If nodes are found with no aliases,
286 * they will be added in any order.
287 *
288 * If there is a gap in the aliases, then this function return a 0 node at
289 * that position. The return value will also count these gaps.
290 *
291 * This function checks node properties and will not return nodes which are
292 * marked disabled (status = "disabled").
293 *
294 * @param blob FDT blob to use
295 * @param name Root name of alias to search for
296 * @param id Compatible ID to look for
297 * @param node_list Place to put list of found nodes
298 * @param maxcount Maximum number of nodes to find
299 * @return number of nodes found on success, FTD_ERR_... on error
300 */
301 int fdtdec_find_aliases_for_id(const void *blob, const char *name,
302 enum fdt_compat_id id, int *node_list, int maxcount);
304 /*
305 * This function is similar to fdtdec_find_aliases_for_id() except that it
306 * adds to the node_list that is passed in. Any 0 elements are considered
307 * available for allocation - others are considered already used and are
308 * skipped.
309 *
310 * You can use this by calling fdtdec_find_aliases_for_id() with an
311 * uninitialised array, then setting the elements that are returned to -1,
312 * say, then calling this function, perhaps with a different compat id.
313 * Any elements you get back that are >0 are new nodes added by the call
314 * to this function.
315 *
316 * Note that if you have some nodes with aliases and some without, you are
317 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
318 * one compat_id may fill in positions for which you have aliases defined
319 * for another compat_id. When you later call *this* function with the second
320 * compat_id, the alias positions may already be used. A debug warning may
321 * be generated in this case, but it is safest to define aliases for all
322 * nodes when you care about the ordering.
323 */
324 int fdtdec_add_aliases_for_id(const void *blob, const char *name,
325 enum fdt_compat_id id, int *node_list, int maxcount);
327 /*
328 * Get the name for a compatible ID
329 *
330 * @param id Compatible ID to look for
331 * @return compatible string for that id
332 */
333 const char *fdtdec_get_compatible(enum fdt_compat_id id);
335 /* Look up a phandle and follow it to its node. Then return the offset
336 * of that node.
337 *
338 * @param blob FDT blob
339 * @param node node to examine
340 * @param prop_name name of property to find
341 * @return node offset if found, -ve error code on error
342 */
343 int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
345 /**
346 * Look up a property in a node and return its contents in an integer
347 * array of given length. The property must have at least enough data for
348 * the array (4*count bytes). It may have more, but this will be ignored.
349 *
350 * @param blob FDT blob
351 * @param node node to examine
352 * @param prop_name name of property to find
353 * @param array array to fill with data
354 * @param count number of array elements
355 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
356 * or -FDT_ERR_BADLAYOUT if not enough data
357 */
358 int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
359 u32 *array, int count);
361 /**
362 * Look up a property in a node and return a pointer to its contents as a
363 * unsigned int array of given length. The property must have at least enough
364 * data for the array ('count' cells). It may have more, but this will be
365 * ignored. The data is not copied.
366 *
367 * Note that you must access elements of the array with fdt32_to_cpu(),
368 * since the elements will be big endian even on a little endian machine.
369 *
370 * @param blob FDT blob
371 * @param node node to examine
372 * @param prop_name name of property to find
373 * @param count number of array elements
374 * @return pointer to array if found, or NULL if the property is not
375 * found or there is not enough data
376 */
377 const u32 *fdtdec_locate_array(const void *blob, int node,
378 const char *prop_name, int count);
380 /**
381 * Look up a boolean property in a node and return it.
382 *
383 * A boolean properly is true if present in the device tree and false if not
384 * present, regardless of its value.
385 *
386 * @param blob FDT blob
387 * @param node node to examine
388 * @param prop_name name of property to find
389 * @return 1 if the properly is present; 0 if it isn't present
390 */
391 int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
393 /**
394 * Decode a single GPIOs from an FDT.
395 *
396 * If the property is not found, then the GPIO structure will still be
397 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
398 * provide optional GPIOs.
399 *
400 * @param blob FDT blob to use
401 * @param node Node to look at
402 * @param prop_name Node property name
403 * @param gpio gpio elements to fill from FDT
404 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
405 */
406 int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
407 struct fdt_gpio_state *gpio);
409 /**
410 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
411 * terminating item.
412 *
413 * @param blob FDT blob to use
414 * @param node Node to look at
415 * @param prop_name Node property name
416 * @param gpio Array of gpio elements to fill from FDT. This will be
417 * untouched if either 0 or an error is returned
418 * @param max_count Maximum number of elements allowed
419 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
420 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
421 */
422 int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
423 struct fdt_gpio_state *gpio, int max_count);
425 /**
426 * Set up a GPIO pin according to the provided gpio information. At present this
427 * just requests the GPIO.
428 *
429 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
430 * deal with optional GPIOs.
431 *
432 * @param gpio GPIO info to use for set up
433 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
434 */
435 int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
437 /**
438 * Look in the FDT for a config item with the given name and return its value
439 * as a 32-bit integer. The property must have at least 4 bytes of data. The
440 * value of the first cell is returned.
441 *
442 * @param blob FDT blob to use
443 * @param prop_name Node property name
444 * @param default_val default value to return if the property is not found
445 * @return integer value, if found, or default_val if not
446 */
447 int fdtdec_get_config_int(const void *blob, const char *prop_name,
448 int default_val);
450 /**
451 * Look in the FDT for a config item with the given name
452 * and return whether it exists.
453 *
454 * @param blob FDT blob
455 * @param prop_name property name to look up
456 * @return 1, if it exists, or 0 if not
457 */
458 int fdtdec_get_config_bool(const void *blob, const char *prop_name);
460 /**
461 * Look in the FDT for a config item with the given name and return its value
462 * as a string.
463 *
464 * @param blob FDT blob
465 * @param prop_name property name to look up
466 * @returns property string, NULL on error.
467 */
468 char *fdtdec_get_config_string(const void *blob, const char *prop_name);
470 /*
471 * Look up a property in a node and return its contents in a byte
472 * array of given length. The property must have at least enough data for
473 * the array (count bytes). It may have more, but this will be ignored.
474 *
475 * @param blob FDT blob
476 * @param node node to examine
477 * @param prop_name name of property to find
478 * @param array array to fill with data
479 * @param count number of array elements
480 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
481 * or -FDT_ERR_BADLAYOUT if not enough data
482 */
483 int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
484 u8 *array, int count);
486 /**
487 * Look up a property in a node and return a pointer to its contents as a
488 * byte array of given length. The property must have at least enough data
489 * for the array (count bytes). It may have more, but this will be ignored.
490 * The data is not copied.
491 *
492 * @param blob FDT blob
493 * @param node node to examine
494 * @param prop_name name of property to find
495 * @param count number of array elements
496 * @return pointer to byte array if found, or NULL if the property is not
497 * found or there is not enough data
498 */
499 const u8 *fdtdec_locate_byte_array(const void *blob, int node,
500 const char *prop_name, int count);
502 /**
503 * Look up a property in a node which contains a memory region address and
504 * size. Then return a pointer to this address.
505 *
506 * The property must hold one address with a length. This is only tested on
507 * 32-bit machines.
508 *
509 * @param blob FDT blob
510 * @param node node to examine
511 * @param prop_name name of property to find
512 * @param ptrp returns pointer to region, or NULL if no address
513 * @param size returns size of region
514 * @return 0 if ok, -1 on error (propery not found)
515 */
516 int fdtdec_decode_region(const void *blob, int node,
517 const char *prop_name, void **ptrp, size_t *size);
518 #endif