summaryrefslogtreecommitdiff
path: root/include/fdtdec.h
blob: 934438cc6ee73293bef5073eb911846d764f72a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
/*
 * Copyright (c) 2011 The Chromium OS Authors.
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#ifndef __fdtdec_h
#define __fdtdec_h

/*
 * This file contains convenience functions for decoding useful and
 * enlightening information from FDTs. It is intended to be used by device
 * drivers and board-specific code within U-Boot. It aims to reduce the
 * amount of FDT munging required within U-Boot itself, so that driver code
 * changes to support FDT are minimized.
 */

#include <libfdt.h>

/*
 * A typedef for a physical address. Note that fdt data is always big
 * endian even on a litle endian machine.
 */
#ifdef CONFIG_PHYS_64BIT
typedef u64 fdt_addr_t;
#define FDT_ADDR_T_NONE (-1ULL)
#define fdt_addr_to_cpu(reg) be64_to_cpu(reg)
#define fdt_size_to_cpu(reg) be64_to_cpu(reg)
#else
typedef u32 fdt_addr_t;
#define FDT_ADDR_T_NONE (-1U)
#define fdt_addr_to_cpu(reg) be32_to_cpu(reg)
#define fdt_size_to_cpu(reg) be32_to_cpu(reg)
#endif

/* Information obtained about memory from the FDT */
struct fdt_memory {
	fdt_addr_t start;
	fdt_addr_t end;
};

/**
 * Compat types that we know about and for which we might have drivers.
 * Each is named COMPAT_<dir>_<filename> where <dir> is the directory
 * within drivers.
 */
enum fdt_compat_id {
	COMPAT_UNKNOWN,
	COMPAT_NVIDIA_TEGRA20_USB,	/* Tegra20 USB port */
	COMPAT_NVIDIA_TEGRA20_I2C,	/* Tegra20 i2c */
	COMPAT_NVIDIA_TEGRA20_DVC,	/* Tegra20 dvc (really just i2c) */
	COMPAT_NVIDIA_TEGRA20_EMC,	/* Tegra20 memory controller */
	COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra20 memory timing table */
	COMPAT_NVIDIA_TEGRA20_KBC,	/* Tegra20 Keyboard */
	COMPAT_NVIDIA_TEGRA20_NAND,	/* Tegra2 NAND controller */
	COMPAT_NVIDIA_TEGRA20_PWM,	/* Tegra 2 PWM controller */
	COMPAT_NVIDIA_TEGRA20_DC,	/* Tegra 2 Display controller */
	COMPAT_SMSC_LAN9215,		/* SMSC 10/100 Ethernet LAN9215 */
	COMPAT_SAMSUNG_EXYNOS5_SROMC,	/* Exynos5 SROMC */
	COMPAT_SAMSUNG_S3C2440_I2C,	/* Exynos I2C Controller */

	COMPAT_COUNT,
};

/* GPIOs are numbered from 0 */
enum {
	FDT_GPIO_NONE = -1U,	/* an invalid GPIO used to end our list */

	FDT_GPIO_ACTIVE_LOW = 1 << 0,	/* input is active low (else high) */
};

/* This is the state of a GPIO pin as defined by the fdt */
struct fdt_gpio_state {
	const char *name;	/* name of the fdt property defining this */
	uint gpio;		/* GPIO number, or FDT_GPIO_NONE if none */
	u8 flags;		/* FDT_GPIO_... flags */
};

/* This tells us whether a fdt_gpio_state record is valid or not */
#define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE)

/**
 * Read the GPIO taking into account the polarity of the pin.
 *
 * @param gpio		pointer to the decoded gpio
 * @return value of the gpio if successful, < 0 if unsuccessful
 */
int fdtdec_get_gpio(struct fdt_gpio_state *gpio);

/**
 * Write the GPIO taking into account the polarity of the pin.
 *
 * @param gpio		pointer to the decoded gpio
 * @return 0 if successful
 */
int fdtdec_set_gpio(struct fdt_gpio_state *gpio, int val);

/**
 * Find the next numbered alias for a peripheral. This is used to enumerate
 * all the peripherals of a certain type.
 *
 * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then
 * this function will return a pointer to the node the alias points to, and
 * then update *upto to 1. Next time you call this function, the next node
 * will be returned.
 *
 * All nodes returned will match the compatible ID, as it is assumed that
 * all peripherals use the same driver.
 *
 * @param blob		FDT blob to use
 * @param name		Root name of alias to search for
 * @param id		Compatible ID to look for
 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 */
int fdtdec_next_alias(const void *blob, const char *name,
		enum fdt_compat_id id, int *upto);

/**
 * Find the compatible ID for a given node.
 *
 * Generally each node has at least one compatible string attached to it.
 * This function looks through our list of known compatible strings and
 * returns the corresponding ID which matches the compatible string.
 *
 * @param blob		FDT blob to use
 * @param node		Node containing compatible string to find
 * @return compatible ID, or COMPAT_UNKNOWN if we cannot find a match
 */
enum fdt_compat_id fdtdec_lookup(const void *blob, int node);

/**
 * Find the next compatible node for a peripheral.
 *
 * Do the first call with node = 0. This function will return a pointer to
 * the next compatible node. Next time you call this function, pass the
 * value returned, and the next node will be provided.
 *
 * @param blob		FDT blob to use
 * @param node		Start node for search
 * @param id		Compatible ID to look for (enum fdt_compat_id)
 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 */
int fdtdec_next_compatible(const void *blob, int node,
		enum fdt_compat_id id);

/**
 * Find the next compatible subnode for a peripheral.
 *
 * Do the first call with node set to the parent and depth = 0. This
 * function will return the offset of the next compatible node. Next time
 * you call this function, pass the node value returned last time, with
 * depth unchanged, and the next node will be provided.
 *
 * @param blob		FDT blob to use
 * @param node		Start node for search
 * @param id		Compatible ID to look for (enum fdt_compat_id)
 * @param depthp	Current depth (set to 0 before first call)
 * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more
 */
int fdtdec_next_compatible_subnode(const void *blob, int node,
		enum fdt_compat_id id, int *depthp);

/**
 * Look up an address property in a node and return it as an address.
 * The property must hold either one address with no trailing data or
 * one address with a length. This is only tested on 32-bit machines.
 *
 * @param blob	FDT blob
 * @param node	node to examine
 * @param prop_name	name of property to find
 * @return address, if found, or FDT_ADDR_T_NONE if not
 */
fdt_addr_t fdtdec_get_addr(const void *blob, int node,
		const char *prop_name);

/**
 * Look up a 32-bit integer property in a node and return it. The property
 * must have at least 4 bytes of data. The value of the first cell is
 * returned.
 *
 * @param blob	FDT blob
 * @param node	node to examine
 * @param prop_name	name of property to find
 * @param default_val	default value to return if the property is not found
 * @return integer value, if found, or default_val if not
 */
s32 fdtdec_get_int(const void *blob, int node, const char *prop_name,
		s32 default_val);

/**
 * Look up a 64-bit integer property in a node and return it. The property
 * must have at least 8 bytes of data (2 cells). The first two cells are
 * concatenated to form a 8 bytes value, where the first cell is top half and
 * the second cell is bottom half.
 *
 * @param blob	FDT blob
 * @param node	node to examine
 * @param prop_name	name of property to find
 * @param default_val	default value to return if the property is not found
 * @return integer value, if found, or default_val if not
 */
uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
		uint64_t default_val);

/**
 * Checks whether a node is enabled.
 * This looks for a 'status' property. If this exists, then returns 1 if
 * the status is 'ok' and 0 otherwise. If there is no status property,
 * it returns 1 on the assumption that anything mentioned should be enabled
 * by default.
 *
 * @param blob	FDT blob
 * @param node	node to examine
 * @return integer value 0 (not enabled) or 1 (enabled)
 */
int fdtdec_get_is_enabled(const void *blob, int node);

/**
 * Make sure we have a valid fdt available to control U-Boot.
 *
 * If not, a message is printed to the console if the console is ready.
 *
 * @return 0 if all ok, -1 if not
 */
int fdtdec_prepare_fdt(void);

/**
 * Checks that we have a valid fdt available to control U-Boot.

 * However, if not then for the moment nothing is done, since this function
 * is called too early to panic().
 *
 * @returns 0
 */
int fdtdec_check_fdt(void);

/**
 * Find the nodes for a peripheral and return a list of them in the correct
 * order. This is used to enumerate all the peripherals of a certain type.
 *
 * To use this, optionally set up a /aliases node with alias properties for
 * a peripheral. For example, for usb you could have:
 *
 * aliases {
 *		usb0 = "/ehci@c5008000";
 *		usb1 = "/ehci@c5000000";
 * };
 *
 * Pass "usb" as the name to this function and will return a list of two
 * nodes offsets: /ehci@c5008000 and ehci@c5000000.
 *
 * All nodes returned will match the compatible ID, as it is assumed that
 * all peripherals use the same driver.
 *
 * If no alias node is found, then the node list will be returned in the
 * order found in the fdt. If the aliases mention a node which doesn't
 * exist, then this will be ignored. If nodes are found with no aliases,
 * they will be added in any order.
 *
 * If there is a gap in the aliases, then this function return a 0 node at
 * that position. The return value will also count these gaps.
 *
 * This function checks node properties and will not return nodes which are
 * marked disabled (status = "disabled").
 *
 * @param blob		FDT blob to use
 * @param name		Root name of alias to search for
 * @param id		Compatible ID to look for
 * @param node_list	Place to put list of found nodes
 * @param maxcount	Maximum number of nodes to find
 * @return number of nodes found on success, FTD_ERR_... on error
 */
int fdtdec_find_aliases_for_id(const void *blob, const char *name,
			enum fdt_compat_id id, int *node_list, int maxcount);

/*
 * This function is similar to fdtdec_find_aliases_for_id() except that it
 * adds to the node_list that is passed in. Any 0 elements are considered
 * available for allocation - others are considered already used and are
 * skipped.
 *
 * You can use this by calling fdtdec_find_aliases_for_id() with an
 * uninitialised array, then setting the elements that are returned to -1,
 * say, then calling this function, perhaps with a different compat id.
 * Any elements you get back that are >0 are new nodes added by the call
 * to this function.
 *
 * Note that if you have some nodes with aliases and some without, you are
 * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with
 * one compat_id may fill in positions for which you have aliases defined
 * for another compat_id. When you later call *this* function with the second
 * compat_id, the alias positions may already be used. A debug warning may
 * be generated in this case, but it is safest to define aliases for all
 * nodes when you care about the ordering.
 */
int fdtdec_add_aliases_for_id(const void *blob, const char *name,
			enum fdt_compat_id id, int *node_list, int maxcount);

/*
 * Get the name for a compatible ID
 *
 * @param id		Compatible ID to look for
 * @return compatible string for that id
 */
const char *fdtdec_get_compatible(enum fdt_compat_id id);

/* Look up a phandle and follow it to its node. Then return the offset
 * of that node.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @return node offset if found, -ve error code on error
 */
int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name);

/**
 * Look up a property in a node and return its contents in an integer
 * array of given length. The property must have at least enough data for
 * the array (4*count bytes). It may have more, but this will be ignored.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param array		array to fill with data
 * @param count		number of array elements
 * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found,
 *		or -FDT_ERR_BADLAYOUT if not enough data
 */
int fdtdec_get_int_array(const void *blob, int node, const char *prop_name,
		u32 *array, int count);

/**
 * Look up a property in a node and return a pointer to its contents as a
 * unsigned int array of given length. The property must have at least enough
 * data for the array ('count' cells). It may have more, but this will be
 * ignored. The data is not copied.
 *
 * Note that you must access elements of the array with fdt32_to_cpu(),
 * since the elements will be big endian even on a little endian machine.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param count		number of array elements
 * @return pointer to array if found, or NULL if the property is not
 *		found or there is not enough data
 */
const u32 *fdtdec_locate_array(const void *blob, int node,
			       const char *prop_name, int count);

/**
 * Look up a boolean property in a node and return it.
 *
 * A boolean properly is true if present in the device tree and false if not
 * present, regardless of its value.
 *
 * @param blob	FDT blob
 * @param node	node to examine
 * @param prop_name	name of property to find
 * @return 1 if the properly is present; 0 if it isn't present
 */
int fdtdec_get_bool(const void *blob, int node, const char *prop_name);

/**
 * Decode a single GPIOs from an FDT.
 *
 * If the property is not found, then the GPIO structure will still be
 * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to
 * provide optional GPIOs.
 *
 * @param blob		FDT blob to use
 * @param node		Node to look at
 * @param prop_name	Node property name
 * @param gpio		gpio elements to fill from FDT
 * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing.
 */
int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name,
		struct fdt_gpio_state *gpio);

/**
 * Decode a list of GPIOs from an FDT. This creates a list of GPIOs with no
 * terminating item.
 *
 * @param blob         FDT blob to use
 * @param node         Node to look at
 * @param prop_name    Node property name
 * @param gpio         Array of gpio elements to fill from FDT. This will be
 *                     untouched if either 0 or an error is returned
 * @param max_count    Maximum number of elements allowed
 * @return number of GPIOs read if ok, -FDT_ERR_BADLAYOUT if max_count would
 * be exceeded, or -FDT_ERR_NOTFOUND if the property is missing.
 */
int fdtdec_decode_gpios(const void *blob, int node, const char *prop_name,
		struct fdt_gpio_state *gpio, int max_count);

/**
 * Set up a GPIO pin according to the provided gpio information. At present this
 * just requests the GPIO.
 *
 * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to
 * deal with optional GPIOs.
 *
 * @param gpio		GPIO info to use for set up
 * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error
 */
int fdtdec_setup_gpio(struct fdt_gpio_state *gpio);

/**
 * Look in the FDT for a config item with the given name and return its value
 * as a 32-bit integer. The property must have at least 4 bytes of data. The
 * value of the first cell is returned.
 *
 * @param blob		FDT blob to use
 * @param prop_name	Node property name
 * @param default_val	default value to return if the property is not found
 * @return integer value, if found, or default_val if not
 */
int fdtdec_get_config_int(const void *blob, const char *prop_name,
		int default_val);

/**
 * Look in the FDT for a config item with the given name
 * and return whether it exists.
 *
 * @param blob		FDT blob
 * @param prop_name	property name to look up
 * @return 1, if it exists, or 0 if not
 */
int fdtdec_get_config_bool(const void *blob, const char *prop_name);

/**
 * Look in the FDT for a config item with the given name and return its value
 * as a string.
 *
 * @param blob          FDT blob
 * @param prop_name     property name to look up
 * @returns property string, NULL on error.
 */
char *fdtdec_get_config_string(const void *blob, const char *prop_name);

/*
 * Look up a property in a node and return its contents in a byte
 * array of given length. The property must have at least enough data for
 * the array (count bytes). It may have more, but this will be ignored.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param array		array to fill with data
 * @param count		number of array elements
 * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found,
 *		or -FDT_ERR_BADLAYOUT if not enough data
 */
int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name,
		u8 *array, int count);

/**
 * Look up a property in a node and return a pointer to its contents as a
 * byte array of given length. The property must have at least enough data
 * for the array (count bytes). It may have more, but this will be ignored.
 * The data is not copied.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param count		number of array elements
 * @return pointer to byte array if found, or NULL if the property is not
 *		found or there is not enough data
 */
const u8 *fdtdec_locate_byte_array(const void *blob, int node,
			     const char *prop_name, int count);

/**
 * Look up a property in a node which contains a memory region address and
 * size. Then return a pointer to this address.
 *
 * The property must hold one address with a length. This is only tested on
 * 32-bit machines.
 *
 * @param blob		FDT blob
 * @param node		node to examine
 * @param prop_name	name of property to find
 * @param ptrp		returns pointer to region, or NULL if no address
 * @param size		returns size of region
 * @return 0 if ok, -1 on error (propery not found)
 */
int fdtdec_decode_region(const void *blob, int node,
		const char *prop_name, void **ptrp, size_t *size);
#endif