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b5220bc6 SG |
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 | */ | |
21 | ||
22 | ||
23 | /* | |
24 | * This file contains convenience functions for decoding useful and | |
25 | * enlightening information from FDTs. It is intended to be used by device | |
26 | * drivers and board-specific code within U-Boot. It aims to reduce the | |
27 | * amount of FDT munging required within U-Boot itself, so that driver code | |
28 | * changes to support FDT are minimized. | |
29 | */ | |
30 | ||
31 | #include <libfdt.h> | |
32 | ||
33 | /* | |
34 | * A typedef for a physical address. Note that fdt data is always big | |
35 | * endian even on a litle endian machine. | |
36 | */ | |
37 | #ifdef CONFIG_PHYS_64BIT | |
38 | typedef u64 fdt_addr_t; | |
39 | #define FDT_ADDR_T_NONE (-1ULL) | |
40 | #define fdt_addr_to_cpu(reg) be64_to_cpu(reg) | |
41 | #else | |
42 | typedef u32 fdt_addr_t; | |
43 | #define FDT_ADDR_T_NONE (-1U) | |
44 | #define fdt_addr_to_cpu(reg) be32_to_cpu(reg) | |
45 | #endif | |
46 | ||
47 | /* Information obtained about memory from the FDT */ | |
48 | struct fdt_memory { | |
49 | fdt_addr_t start; | |
50 | fdt_addr_t end; | |
51 | }; | |
52 | ||
53 | /** | |
54 | * Compat types that we know about and for which we might have drivers. | |
55 | * Each is named COMPAT_<dir>_<filename> where <dir> is the directory | |
56 | * within drivers. | |
57 | */ | |
58 | enum fdt_compat_id { | |
59 | COMPAT_UNKNOWN, | |
87f938c9 | 60 | COMPAT_NVIDIA_TEGRA20_USB, /* Tegra2 USB port */ |
96a78ac0 YL |
61 | COMPAT_NVIDIA_TEGRA20_I2C, /* Tegra2 i2c */ |
62 | COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra2 dvc (really just i2c) */ | |
0e35ad05 JZ |
63 | COMPAT_NVIDIA_TEGRA20_EMC, /* Tegra2 memory controller */ |
64 | COMPAT_NVIDIA_TEGRA20_EMC_TABLE, /* Tegra2 memory timing table */ | |
6642a681 | 65 | COMPAT_NVIDIA_TEGRA20_KBC, /* Tegra2 Keyboard */ |
b5220bc6 SG |
66 | |
67 | COMPAT_COUNT, | |
68 | }; | |
69 | ||
ed3ee5cd SG |
70 | /* GPIOs are numbered from 0 */ |
71 | enum { | |
72 | FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ | |
73 | ||
74 | FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ | |
75 | }; | |
76 | ||
77 | /* This is the state of a GPIO pin as defined by the fdt */ | |
78 | struct fdt_gpio_state { | |
79 | const char *name; /* name of the fdt property defining this */ | |
80 | uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ | |
81 | u8 flags; /* FDT_GPIO_... flags */ | |
82 | }; | |
83 | ||
84 | /* This tells us whether a fdt_gpio_state record is valid or not */ | |
85 | #define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) | |
86 | ||
b5220bc6 SG |
87 | /** |
88 | * Find the next numbered alias for a peripheral. This is used to enumerate | |
89 | * all the peripherals of a certain type. | |
90 | * | |
91 | * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then | |
92 | * this function will return a pointer to the node the alias points to, and | |
93 | * then update *upto to 1. Next time you call this function, the next node | |
94 | * will be returned. | |
95 | * | |
96 | * All nodes returned will match the compatible ID, as it is assumed that | |
97 | * all peripherals use the same driver. | |
98 | * | |
99 | * @param blob FDT blob to use | |
100 | * @param name Root name of alias to search for | |
101 | * @param id Compatible ID to look for | |
102 | * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more | |
103 | */ | |
104 | int fdtdec_next_alias(const void *blob, const char *name, | |
105 | enum fdt_compat_id id, int *upto); | |
106 | ||
f88fe2de SG |
107 | /** |
108 | * Find the next compatible node for a peripheral. | |
109 | * | |
110 | * Do the first call with node = 0. This function will return a pointer to | |
111 | * the next compatible node. Next time you call this function, pass the | |
112 | * value returned, and the next node will be provided. | |
113 | * | |
114 | * @param blob FDT blob to use | |
115 | * @param node Start node for search | |
116 | * @param id Compatible ID to look for (enum fdt_compat_id) | |
117 | * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more | |
118 | */ | |
119 | int fdtdec_next_compatible(const void *blob, int node, | |
120 | enum fdt_compat_id id); | |
121 | ||
3ddecfc7 SG |
122 | /** |
123 | * Find the next compatible subnode for a peripheral. | |
124 | * | |
125 | * Do the first call with node set to the parent and depth = 0. This | |
126 | * function will return the offset of the next compatible node. Next time | |
127 | * you call this function, pass the node value returned last time, with | |
128 | * depth unchanged, and the next node will be provided. | |
129 | * | |
130 | * @param blob FDT blob to use | |
131 | * @param node Start node for search | |
132 | * @param id Compatible ID to look for (enum fdt_compat_id) | |
133 | * @param depthp Current depth (set to 0 before first call) | |
134 | * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more | |
135 | */ | |
136 | int fdtdec_next_compatible_subnode(const void *blob, int node, | |
137 | enum fdt_compat_id id, int *depthp); | |
138 | ||
b5220bc6 SG |
139 | /** |
140 | * Look up an address property in a node and return it as an address. | |
141 | * The property must hold either one address with no trailing data or | |
142 | * one address with a length. This is only tested on 32-bit machines. | |
143 | * | |
144 | * @param blob FDT blob | |
145 | * @param node node to examine | |
146 | * @param prop_name name of property to find | |
147 | * @return address, if found, or FDT_ADDR_T_NONE if not | |
148 | */ | |
149 | fdt_addr_t fdtdec_get_addr(const void *blob, int node, | |
150 | const char *prop_name); | |
151 | ||
152 | /** | |
153 | * Look up a 32-bit integer property in a node and return it. The property | |
154 | * must have at least 4 bytes of data. The value of the first cell is | |
155 | * returned. | |
156 | * | |
157 | * @param blob FDT blob | |
158 | * @param node node to examine | |
159 | * @param prop_name name of property to find | |
160 | * @param default_val default value to return if the property is not found | |
161 | * @return integer value, if found, or default_val if not | |
162 | */ | |
163 | s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, | |
164 | s32 default_val); | |
165 | ||
166 | /** | |
167 | * Checks whether a node is enabled. | |
168 | * This looks for a 'status' property. If this exists, then returns 1 if | |
169 | * the status is 'ok' and 0 otherwise. If there is no status property, | |
f88fe2de SG |
170 | * it returns 1 on the assumption that anything mentioned should be enabled |
171 | * by default. | |
b5220bc6 SG |
172 | * |
173 | * @param blob FDT blob | |
174 | * @param node node to examine | |
f88fe2de | 175 | * @return integer value 0 (not enabled) or 1 (enabled) |
b5220bc6 | 176 | */ |
f88fe2de | 177 | int fdtdec_get_is_enabled(const void *blob, int node); |
b5220bc6 SG |
178 | |
179 | /** | |
9a263e55 SG |
180 | * Make sure we have a valid fdt available to control U-Boot. |
181 | * | |
182 | * If not, a message is printed to the console if the console is ready. | |
183 | * | |
184 | * @return 0 if all ok, -1 if not | |
185 | */ | |
186 | int fdtdec_prepare_fdt(void); | |
187 | ||
188 | /** | |
189 | * Checks that we have a valid fdt available to control U-Boot. | |
190 | ||
191 | * However, if not then for the moment nothing is done, since this function | |
192 | * is called too early to panic(). | |
193 | * | |
194 | * @returns 0 | |
b5220bc6 SG |
195 | */ |
196 | int fdtdec_check_fdt(void); | |
a53f4a29 SG |
197 | |
198 | /** | |
199 | * Find the nodes for a peripheral and return a list of them in the correct | |
200 | * order. This is used to enumerate all the peripherals of a certain type. | |
201 | * | |
202 | * To use this, optionally set up a /aliases node with alias properties for | |
203 | * a peripheral. For example, for usb you could have: | |
204 | * | |
205 | * aliases { | |
206 | * usb0 = "/ehci@c5008000"; | |
207 | * usb1 = "/ehci@c5000000"; | |
208 | * }; | |
209 | * | |
210 | * Pass "usb" as the name to this function and will return a list of two | |
211 | * nodes offsets: /ehci@c5008000 and ehci@c5000000. | |
212 | * | |
213 | * All nodes returned will match the compatible ID, as it is assumed that | |
214 | * all peripherals use the same driver. | |
215 | * | |
216 | * If no alias node is found, then the node list will be returned in the | |
217 | * order found in the fdt. If the aliases mention a node which doesn't | |
218 | * exist, then this will be ignored. If nodes are found with no aliases, | |
219 | * they will be added in any order. | |
220 | * | |
221 | * If there is a gap in the aliases, then this function return a 0 node at | |
222 | * that position. The return value will also count these gaps. | |
223 | * | |
224 | * This function checks node properties and will not return nodes which are | |
225 | * marked disabled (status = "disabled"). | |
226 | * | |
227 | * @param blob FDT blob to use | |
228 | * @param name Root name of alias to search for | |
229 | * @param id Compatible ID to look for | |
230 | * @param node_list Place to put list of found nodes | |
231 | * @param maxcount Maximum number of nodes to find | |
232 | * @return number of nodes found on success, FTD_ERR_... on error | |
233 | */ | |
234 | int fdtdec_find_aliases_for_id(const void *blob, const char *name, | |
235 | enum fdt_compat_id id, int *node_list, int maxcount); | |
236 | ||
c6782270 SG |
237 | /* |
238 | * This function is similar to fdtdec_find_aliases_for_id() except that it | |
239 | * adds to the node_list that is passed in. Any 0 elements are considered | |
240 | * available for allocation - others are considered already used and are | |
241 | * skipped. | |
242 | * | |
243 | * You can use this by calling fdtdec_find_aliases_for_id() with an | |
244 | * uninitialised array, then setting the elements that are returned to -1, | |
245 | * say, then calling this function, perhaps with a different compat id. | |
246 | * Any elements you get back that are >0 are new nodes added by the call | |
247 | * to this function. | |
248 | * | |
249 | * Note that if you have some nodes with aliases and some without, you are | |
250 | * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with | |
251 | * one compat_id may fill in positions for which you have aliases defined | |
252 | * for another compat_id. When you later call *this* function with the second | |
253 | * compat_id, the alias positions may already be used. A debug warning may | |
254 | * be generated in this case, but it is safest to define aliases for all | |
255 | * nodes when you care about the ordering. | |
256 | */ | |
257 | int fdtdec_add_aliases_for_id(const void *blob, const char *name, | |
258 | enum fdt_compat_id id, int *node_list, int maxcount); | |
259 | ||
a53f4a29 SG |
260 | /* |
261 | * Get the name for a compatible ID | |
262 | * | |
263 | * @param id Compatible ID to look for | |
264 | * @return compatible string for that id | |
265 | */ | |
266 | const char *fdtdec_get_compatible(enum fdt_compat_id id); | |
d17da655 SG |
267 | |
268 | /* Look up a phandle and follow it to its node. Then return the offset | |
269 | * of that node. | |
270 | * | |
271 | * @param blob FDT blob | |
272 | * @param node node to examine | |
273 | * @param prop_name name of property to find | |
274 | * @return node offset if found, -ve error code on error | |
275 | */ | |
276 | int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); | |
277 | ||
278 | /** | |
279 | * Look up a property in a node and return its contents in an integer | |
280 | * array of given length. The property must have at least enough data for | |
281 | * the array (4*count bytes). It may have more, but this will be ignored. | |
282 | * | |
283 | * @param blob FDT blob | |
284 | * @param node node to examine | |
285 | * @param prop_name name of property to find | |
286 | * @param array array to fill with data | |
287 | * @param count number of array elements | |
288 | * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, | |
289 | * or -FDT_ERR_BADLAYOUT if not enough data | |
290 | */ | |
291 | int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, | |
292 | u32 *array, int count); | |
293 | ||
96875e7d SG |
294 | /** |
295 | * Look up a property in a node and return a pointer to its contents as a | |
296 | * unsigned int array of given length. The property must have at least enough | |
297 | * data for the array ('count' cells). It may have more, but this will be | |
298 | * ignored. The data is not copied. | |
299 | * | |
300 | * Note that you must access elements of the array with fdt32_to_cpu(), | |
301 | * since the elements will be big endian even on a little endian machine. | |
302 | * | |
303 | * @param blob FDT blob | |
304 | * @param node node to examine | |
305 | * @param prop_name name of property to find | |
306 | * @param count number of array elements | |
307 | * @return pointer to array if found, or NULL if the property is not | |
308 | * found or there is not enough data | |
309 | */ | |
310 | const u32 *fdtdec_locate_array(const void *blob, int node, | |
311 | const char *prop_name, int count); | |
312 | ||
d17da655 SG |
313 | /** |
314 | * Look up a boolean property in a node and return it. | |
315 | * | |
316 | * A boolean properly is true if present in the device tree and false if not | |
317 | * present, regardless of its value. | |
318 | * | |
319 | * @param blob FDT blob | |
320 | * @param node node to examine | |
321 | * @param prop_name name of property to find | |
322 | * @return 1 if the properly is present; 0 if it isn't present | |
323 | */ | |
324 | int fdtdec_get_bool(const void *blob, int node, const char *prop_name); | |
ed3ee5cd SG |
325 | |
326 | /** | |
327 | * Decode a single GPIOs from an FDT. | |
328 | * | |
329 | * If the property is not found, then the GPIO structure will still be | |
330 | * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to | |
331 | * provide optional GPIOs. | |
332 | * | |
333 | * @param blob FDT blob to use | |
334 | * @param node Node to look at | |
335 | * @param prop_name Node property name | |
336 | * @param gpio gpio elements to fill from FDT | |
337 | * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. | |
338 | */ | |
339 | int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, | |
340 | struct fdt_gpio_state *gpio); | |
341 | ||
342 | /** | |
343 | * Set up a GPIO pin according to the provided gpio information. At present this | |
344 | * just requests the GPIO. | |
345 | * | |
346 | * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to | |
347 | * deal with optional GPIOs. | |
348 | * | |
349 | * @param gpio GPIO info to use for set up | |
350 | * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error | |
351 | */ | |
352 | int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); | |
bed4d892 AS |
353 | |
354 | /* | |
355 | * Look up a property in a node and return its contents in a byte | |
356 | * array of given length. The property must have at least enough data for | |
357 | * the array (count bytes). It may have more, but this will be ignored. | |
358 | * | |
359 | * @param blob FDT blob | |
360 | * @param node node to examine | |
361 | * @param prop_name name of property to find | |
362 | * @param array array to fill with data | |
363 | * @param count number of array elements | |
364 | * @return 0 if ok, or -FDT_ERR_MISSING if the property is not found, | |
365 | * or -FDT_ERR_BADLAYOUT if not enough data | |
366 | */ | |
367 | int fdtdec_get_byte_array(const void *blob, int node, const char *prop_name, | |
368 | u8 *array, int count); | |
369 | ||
370 | /** | |
371 | * Look up a property in a node and return a pointer to its contents as a | |
372 | * byte array of given length. The property must have at least enough data | |
373 | * for the array (count bytes). It may have more, but this will be ignored. | |
374 | * The data is not copied. | |
375 | * | |
376 | * @param blob FDT blob | |
377 | * @param node node to examine | |
378 | * @param prop_name name of property to find | |
379 | * @param count number of array elements | |
380 | * @return pointer to byte array if found, or NULL if the property is not | |
381 | * found or there is not enough data | |
382 | */ | |
383 | const u8 *fdtdec_locate_byte_array(const void *blob, int node, | |
384 | const char *prop_name, int count); |