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Simon Glassb5220bc2011-10-24 19:15:32 +00001/*
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 */
21
Simon Glass5bfa78d2012-07-12 05:25:02 +000022#ifndef __fdtdec_h
23#define __fdtdec_h
Simon Glassb5220bc2011-10-24 19:15:32 +000024
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 */
32
33#include <libfdt.h>
34
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
40typedef u64 fdt_addr_t;
41#define FDT_ADDR_T_NONE (-1ULL)
42#define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
Simon Glassf20c4612012-10-25 16:31:00 +000043#define fdt_size_to_cpu(reg) be64_to_cpu(reg)
Simon Glassb5220bc2011-10-24 19:15:32 +000044#else
45typedef u32 fdt_addr_t;
46#define FDT_ADDR_T_NONE (-1U)
47#define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
Simon Glassf20c4612012-10-25 16:31:00 +000048#define fdt_size_to_cpu(reg) be32_to_cpu(reg)
Simon Glassb5220bc2011-10-24 19:15:32 +000049#endif
50
51/* Information obtained about memory from the FDT */
52struct fdt_memory {
53 fdt_addr_t start;
54 fdt_addr_t end;
55};
56
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 */
62enum fdt_compat_id {
63 COMPAT_UNKNOWN,
Allen Martin00a27492012-08-31 08:30:00 +000064 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 */
Jim Lin312693c2012-07-29 20:53:29 +000070 COMPAT_NVIDIA_TEGRA20_NAND, /* Tegra2 NAND controller */
Simon Glasse1ae0d12012-10-17 13:24:49 +000071 COMPAT_NVIDIA_TEGRA20_PWM, /* Tegra 2 PWM controller */
Wei Ni87540de2012-10-17 13:24:50 +000072 COMPAT_NVIDIA_TEGRA20_DC, /* Tegra 2 Display controller */
Simon Glassb5220bc2011-10-24 19:15:32 +000073
74 COMPAT_COUNT,
75};
76
Simon Glassed3ee5c2012-02-27 10:52:36 +000077/* GPIOs are numbered from 0 */
78enum {
79 FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */
80
81 FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */
82};
83
84/* This is the state of a GPIO pin as defined by the fdt */
85struct fdt_gpio_state {
86 const char *name; /* name of the fdt property defining this */
87 uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */
88 u8 flags; /* FDT_GPIO_... flags */
89};
90
91/* This tells us whether a fdt_gpio_state record is valid or not */
92#define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)
93
Simon Glassb5220bc2011-10-24 19:15:32 +000094/**
Sean Paul202ff752012-10-25 16:31:06 +000095 * Read the GPIO taking into account the polarity of the pin.
96 *
97 * @param gpio pointer to the decoded gpio
98 * @return value of the gpio if successful, < 0 if unsuccessful
99 */
100int fdtdec_get_gpio(struct fdt_gpio_state *gpio);
101
102/**
103 * Write the GPIO taking into account the polarity of the pin.
104 *
105 * @param gpio pointer to the decoded gpio
106 * @return 0 if successful
107 */
108int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);
109
110/**
Simon Glassb5220bc2011-10-24 19:15:32 +0000111 * Find the next numbered alias for a peripheral. This is used to enumerate
112 * all the peripherals of a certain type.
113 *
114 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
115 * this function will return a pointer to the node the alias points to, and
116 * then update *upto to 1. Next time you call this function, the next node
117 * will be returned.
118 *
119 * All nodes returned will match the compatible ID, as it is assumed that
120 * all peripherals use the same driver.
121 *
122 * @param blob FDT blob to use
123 * @param name Root name of alias to search for
124 * @param id Compatible ID to look for
125 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
126 */
127int fdtdec_next_alias(const void *blob, const char *name,
128 enum fdt_compat_id id, int *upto);
129
130/**
Gerald Van Baren7cde3972012-11-12 23:13:54 -0500131 * Find the compatible ID for a given node.
132 *
133 * Generally each node has at least one compatible string attached to it.
134 * This function looks through our list of known compatible strings and
135 * returns the corresponding ID which matches the compatible string.
136 *
137 * @param blob FDT blob to use
138 * @param node Node containing compatible string to find
139 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
140 */
141enum fdt_compat_id fdtdec_lookup(const void *blob, int node);
142
143/**
Simon Glassf88fe2d2012-02-27 10:52:34 +0000144 * Find the next compatible node for a peripheral.
145 *
146 * Do the first call with node = 0. This function will return a pointer to
147 * the next compatible node. Next time you call this function, pass the
148 * value returned, and the next node will be provided.
149 *
150 * @param blob FDT blob to use
151 * @param node Start node for search
152 * @param id Compatible ID to look for (enum fdt_compat_id)
153 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
154 */
155int fdtdec_next_compatible(const void *blob, int node,
156 enum fdt_compat_id id);
157
158/**
Simon Glass3ddecfc2012-04-02 13:18:42 +0000159 * Find the next compatible subnode for a peripheral.
160 *
161 * Do the first call with node set to the parent and depth = 0. This
162 * function will return the offset of the next compatible node. Next time
163 * you call this function, pass the node value returned last time, with
164 * depth unchanged, 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 * @param depthp Current depth (set to 0 before first call)
170 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
171 */
172int fdtdec_next_compatible_subnode(const void *blob, int node,
173 enum fdt_compat_id id, int *depthp);
174
175/**
Simon Glassb5220bc2011-10-24 19:15:32 +0000176 * Look up an address property in a node and return it as an address.
177 * The property must hold either one address with no trailing data or
178 * one address with a length. This is only tested on 32-bit machines.
179 *
180 * @param blob FDT blob
181 * @param node node to examine
182 * @param prop_name name of property to find
183 * @return address, if found, or FDT_ADDR_T_NONE if not
184 */
185fdt_addr_t fdtdec_get_addr(const void *blob, int node,
186 const char *prop_name);
187
188/**
189 * Look up a 32-bit integer property in a node and return it. The property
190 * must have at least 4 bytes of data. The value of the first cell is
191 * returned.
192 *
193 * @param blob FDT blob
194 * @param node node to examine
195 * @param prop_name name of property to find
196 * @param default_val default value to return if the property is not found
197 * @return integer value, if found, or default_val if not
198 */
199s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
200 s32 default_val);
201
202/**
Che-Liang Chiouaadef0a2012-10-25 16:31:05 +0000203 * Look up a 64-bit integer property in a node and return it. The property
204 * must have at least 8 bytes of data (2 cells). The first two cells are
205 * concatenated to form a 8 bytes value, where the first cell is top half and
206 * the second cell is bottom half.
207 *
208 * @param blob FDT blob
209 * @param node node to examine
210 * @param prop_name name of property to find
211 * @param default_val default value to return if the property is not found
212 * @return integer value, if found, or default_val if not
213 */
214uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
215 uint64_t default_val);
216
217/**
Simon Glassb5220bc2011-10-24 19:15:32 +0000218 * Checks whether a node is enabled.
219 * This looks for a 'status' property. If this exists, then returns 1 if
220 * the status is 'ok' and 0 otherwise. If there is no status property,
Simon Glassf88fe2d2012-02-27 10:52:34 +0000221 * it returns 1 on the assumption that anything mentioned should be enabled
222 * by default.
Simon Glassb5220bc2011-10-24 19:15:32 +0000223 *
224 * @param blob FDT blob
225 * @param node node to examine
Simon Glassf88fe2d2012-02-27 10:52:34 +0000226 * @return integer value 0 (not enabled) or 1 (enabled)
Simon Glassb5220bc2011-10-24 19:15:32 +0000227 */
Simon Glassf88fe2d2012-02-27 10:52:34 +0000228int fdtdec_get_is_enabled(const void *blob, int node);
Simon Glassb5220bc2011-10-24 19:15:32 +0000229
230/**
Simon Glass9a263e52012-03-28 10:08:24 +0000231 * Make sure we have a valid fdt available to control U-Boot.
232 *
233 * If not, a message is printed to the console if the console is ready.
234 *
235 * @return 0 if all ok, -1 if not
236 */
237int fdtdec_prepare_fdt(void);
238
239/**
240 * Checks that we have a valid fdt available to control U-Boot.
241
242 * However, if not then for the moment nothing is done, since this function
243 * is called too early to panic().
244 *
245 * @returns 0
Simon Glassb5220bc2011-10-24 19:15:32 +0000246 */
247int fdtdec_check_fdt(void);
Simon Glassa53f4a22012-01-17 08:20:50 +0000248
249/**
250 * Find the nodes for a peripheral and return a list of them in the correct
251 * order. This is used to enumerate all the peripherals of a certain type.
252 *
253 * To use this, optionally set up a /aliases node with alias properties for
254 * a peripheral. For example, for usb you could have:
255 *
256 * aliases {
257 * usb0 = "/ehci@c5008000";
258 * usb1 = "/ehci@c5000000";
259 * };
260 *
261 * Pass "usb" as the name to this function and will return a list of two
262 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
263 *
264 * All nodes returned will match the compatible ID, as it is assumed that
265 * all peripherals use the same driver.
266 *
267 * If no alias node is found, then the node list will be returned in the
268 * order found in the fdt. If the aliases mention a node which doesn't
269 * exist, then this will be ignored. If nodes are found with no aliases,
270 * they will be added in any order.
271 *
272 * If there is a gap in the aliases, then this function return a 0 node at
273 * that position. The return value will also count these gaps.
274 *
275 * This function checks node properties and will not return nodes which are
276 * marked disabled (status = "disabled").
277 *
278 * @param blob FDT blob to use
279 * @param name Root name of alias to search for
280 * @param id Compatible ID to look for
281 * @param node_list Place to put list of found nodes
282 * @param maxcount Maximum number of nodes to find
283 * @return number of nodes found on success, FTD_ERR_... on error
284 */
285int fdtdec_find_aliases_for_id(const void *blob, const char *name,
286 enum fdt_compat_id id, int *node_list, int maxcount);
287
288/*
Simon Glassc6782272012-02-03 15:13:53 +0000289 * This function is similar to fdtdec_find_aliases_for_id() except that it
290 * adds to the node_list that is passed in. Any 0 elements are considered
291 * available for allocation - others are considered already used and are
292 * skipped.
293 *
294 * You can use this by calling fdtdec_find_aliases_for_id() with an
295 * uninitialised array, then setting the elements that are returned to -1,
296 * say, then calling this function, perhaps with a different compat id.
297 * Any elements you get back that are >0 are new nodes added by the call
298 * to this function.
299 *
300 * Note that if you have some nodes with aliases and some without, you are
301 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
302 * one compat_id may fill in positions for which you have aliases defined
303 * for another compat_id. When you later call *this* function with the second
304 * compat_id, the alias positions may already be used. A debug warning may
305 * be generated in this case, but it is safest to define aliases for all
306 * nodes when you care about the ordering.
307 */
308int fdtdec_add_aliases_for_id(const void *blob, const char *name,
309 enum fdt_compat_id id, int *node_list, int maxcount);
310
311/*
Simon Glassa53f4a22012-01-17 08:20:50 +0000312 * Get the name for a compatible ID
313 *
314 * @param id Compatible ID to look for
315 * @return compatible string for that id
316 */
317const char *fdtdec_get_compatible(enum fdt_compat_id id);
Simon Glassd17da652012-02-27 10:52:35 +0000318
319/* Look up a phandle and follow it to its node. Then return the offset
320 * of that node.
321 *
322 * @param blob FDT blob
323 * @param node node to examine
324 * @param prop_name name of property to find
325 * @return node offset if found, -ve error code on error
326 */
327int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);
328
329/**
330 * Look up a property in a node and return its contents in an integer
331 * array of given length. The property must have at least enough data for
332 * the array (4*count bytes). It may have more, but this will be ignored.
333 *
334 * @param blob FDT blob
335 * @param node node to examine
336 * @param prop_name name of property to find
337 * @param array array to fill with data
338 * @param count number of array elements
339 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
340 * or -FDT_ERR_BADLAYOUT if not enough data
341 */
342int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
343 u32 *array, int count);
344
345/**
Simon Glass96875e72012-04-02 13:18:41 +0000346 * Look up a property in a node and return a pointer to its contents as a
347 * unsigned int array of given length. The property must have at least enough
348 * data for the array ('count' cells). It may have more, but this will be
349 * ignored. The data is not copied.
350 *
351 * Note that you must access elements of the array with fdt32_to_cpu(),
352 * since the elements will be big endian even on a little endian machine.
353 *
354 * @param blob FDT blob
355 * @param node node to examine
356 * @param prop_name name of property to find
357 * @param count number of array elements
358 * @return pointer to array if found, or NULL if the property is not
359 * found or there is not enough data
360 */
361const u32 *fdtdec_locate_array(const void *blob, int node,
362 const char *prop_name, int count);
363
364/**
Simon Glassd17da652012-02-27 10:52:35 +0000365 * Look up a boolean property in a node and return it.
366 *
367 * A boolean properly is true if present in the device tree and false if not
368 * present, regardless of its value.
369 *
370 * @param blob FDT blob
371 * @param node node to examine
372 * @param prop_name name of property to find
373 * @return 1 if the properly is present; 0 if it isn't present
374 */
375int fdtdec_get_bool(const void *blob, int node, const char *prop_name);
Simon Glassed3ee5c2012-02-27 10:52:36 +0000376
377/**
378 * Decode a single GPIOs from an FDT.
379 *
380 * If the property is not found, then the GPIO structure will still be
381 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
382 * provide optional GPIOs.
383 *
384 * @param blob FDT blob to use
385 * @param node Node to look at
386 * @param prop_name Node property name
387 * @param gpio gpio elements to fill from FDT
388 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
389 */
390int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
391 struct fdt_gpio_state *gpio);
392
393/**
Abhilash Kesavan5921f6a2012-10-25 16:31:01 +0000394 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
395 * terminating item.
396 *
397 * @param blob FDT blob to use
398 * @param node Node to look at
399 * @param prop_name Node property name
400 * @param gpio Array of gpio elements to fill from FDT. This will be
401 * untouched if either 0 or an error is returned
402 * @param max_count Maximum number of elements allowed
403 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
404 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
405 */
406int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
407 struct fdt_gpio_state *gpio, int max_count);
408
409/**
Simon Glassed3ee5c2012-02-27 10:52:36 +0000410 * Set up a GPIO pin according to the provided gpio information. At present this
411 * just requests the GPIO.
412 *
413 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
414 * deal with optional GPIOs.
415 *
416 * @param gpio GPIO info to use for set up
417 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
418 */
419int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);
Anton Staffbed4d892012-04-17 09:01:28 +0000420
Abhilash Kesavan09258f12012-10-25 16:30:58 +0000421/**
422 * Look in the FDT for a config item with the given name and return its value
423 * as a 32-bit integer. The property must have at least 4 bytes of data. The
424 * value of the first cell is returned.
425 *
426 * @param blob FDT blob to use
427 * @param prop_name Node property name
428 * @param default_val default value to return if the property is not found
429 * @return integer value, if found, or default_val if not
430 */
431int fdtdec_get_config_int(const void *blob, const char *prop_name,
432 int default_val);
433
Simon Glass332ab0d2012-10-25 16:30:59 +0000434/**
Gabe Black79289c02012-10-25 16:31:04 +0000435 * Look in the FDT for a config item with the given name
436 * and return whether it exists.
437 *
438 * @param blob FDT blob
439 * @param prop_name property name to look up
440 * @return 1, if it exists, or 0 if not
441 */
442int fdtdec_get_config_bool(const void *blob, const char *prop_name);
443
444/**
Simon Glass332ab0d2012-10-25 16:30:59 +0000445 * Look in the FDT for a config item with the given name and return its value
446 * as a string.
447 *
448 * @param blob FDT blob
449 * @param prop_name property name to look up
450 * @returns property string, NULL on error.
451 */
452char *fdtdec_get_config_string(const void *blob, const char *prop_name);
453
Anton Staffbed4d892012-04-17 09:01:28 +0000454/*
455 * Look up a property in a node and return its contents in a byte
456 * array of given length. The property must have at least enough data for
457 * the array (count bytes). It may have more, but this will be ignored.
458 *
459 * @param blob FDT blob
460 * @param node node to examine
461 * @param prop_name name of property to find
462 * @param array array to fill with data
463 * @param count number of array elements
464 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
465 * or -FDT_ERR_BADLAYOUT if not enough data
466 */
467int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
468 u8 *array, int count);
469
470/**
471 * Look up a property in a node and return a pointer to its contents as a
472 * byte array of given length. The property must have at least enough data
473 * for the array (count bytes). It may have more, but this will be ignored.
474 * The data is not copied.
475 *
476 * @param blob FDT blob
477 * @param node node to examine
478 * @param prop_name name of property to find
479 * @param count number of array elements
480 * @return pointer to byte array if found, or NULL if the property is not
481 * found or there is not enough data
482 */
483const u8 *fdtdec_locate_byte_array(const void *blob, int node,
484 const char *prop_name, int count);
Simon Glassf20c4612012-10-25 16:31:00 +0000485
486/**
487 * Look up a property in a node which contains a memory region address and
488 * size. Then return a pointer to this address.
489 *
490 * The property must hold one address with a length. This is only tested on
491 * 32-bit machines.
492 *
493 * @param blob FDT blob
494 * @param node node to examine
495 * @param prop_name name of property to find
496 * @param ptrp returns pointer to region, or NULL if no address
497 * @param size returns size of region
498 * @return 0 if ok, -1 on error (propery not found)
499 */
500int fdtdec_decode_region(const void *blob, int node,
501 const char *prop_name, void **ptrp, size_t *size);
Simon Glass5bfa78d2012-07-12 05:25:02 +0000502#endif