Simon Glass | b5220bc | 2011-10-24 19:15:32 +0000 | [diff] [blame] | 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, |
| 60 | |
| 61 | COMPAT_COUNT, |
| 62 | }; |
| 63 | |
| 64 | /** |
| 65 | * Find the next numbered alias for a peripheral. This is used to enumerate |
| 66 | * all the peripherals of a certain type. |
| 67 | * |
| 68 | * Do the first call with *upto = 0. Assuming /aliases/<name>0 exists then |
| 69 | * this function will return a pointer to the node the alias points to, and |
| 70 | * then update *upto to 1. Next time you call this function, the next node |
| 71 | * will be returned. |
| 72 | * |
| 73 | * All nodes returned will match the compatible ID, as it is assumed that |
| 74 | * all peripherals use the same driver. |
| 75 | * |
| 76 | * @param blob FDT blob to use |
| 77 | * @param name Root name of alias to search for |
| 78 | * @param id Compatible ID to look for |
| 79 | * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more |
| 80 | */ |
| 81 | int fdtdec_next_alias(const void *blob, const char *name, |
| 82 | enum fdt_compat_id id, int *upto); |
| 83 | |
| 84 | /** |
Simon Glass | f88fe2d | 2012-02-27 10:52:34 +0000 | [diff] [blame^] | 85 | * Find the next compatible node for a peripheral. |
| 86 | * |
| 87 | * Do the first call with node = 0. This function will return a pointer to |
| 88 | * the next compatible node. Next time you call this function, pass the |
| 89 | * value returned, and the next node will be provided. |
| 90 | * |
| 91 | * @param blob FDT blob to use |
| 92 | * @param node Start node for search |
| 93 | * @param id Compatible ID to look for (enum fdt_compat_id) |
| 94 | * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more |
| 95 | */ |
| 96 | int fdtdec_next_compatible(const void *blob, int node, |
| 97 | enum fdt_compat_id id); |
| 98 | |
| 99 | /** |
Simon Glass | b5220bc | 2011-10-24 19:15:32 +0000 | [diff] [blame] | 100 | * Look up an address property in a node and return it as an address. |
| 101 | * The property must hold either one address with no trailing data or |
| 102 | * one address with a length. This is only tested on 32-bit machines. |
| 103 | * |
| 104 | * @param blob FDT blob |
| 105 | * @param node node to examine |
| 106 | * @param prop_name name of property to find |
| 107 | * @return address, if found, or FDT_ADDR_T_NONE if not |
| 108 | */ |
| 109 | fdt_addr_t fdtdec_get_addr(const void *blob, int node, |
| 110 | const char *prop_name); |
| 111 | |
| 112 | /** |
| 113 | * Look up a 32-bit integer property in a node and return it. The property |
| 114 | * must have at least 4 bytes of data. The value of the first cell is |
| 115 | * returned. |
| 116 | * |
| 117 | * @param blob FDT blob |
| 118 | * @param node node to examine |
| 119 | * @param prop_name name of property to find |
| 120 | * @param default_val default value to return if the property is not found |
| 121 | * @return integer value, if found, or default_val if not |
| 122 | */ |
| 123 | s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, |
| 124 | s32 default_val); |
| 125 | |
| 126 | /** |
| 127 | * Checks whether a node is enabled. |
| 128 | * This looks for a 'status' property. If this exists, then returns 1 if |
| 129 | * the status is 'ok' and 0 otherwise. If there is no status property, |
Simon Glass | f88fe2d | 2012-02-27 10:52:34 +0000 | [diff] [blame^] | 130 | * it returns 1 on the assumption that anything mentioned should be enabled |
| 131 | * by default. |
Simon Glass | b5220bc | 2011-10-24 19:15:32 +0000 | [diff] [blame] | 132 | * |
| 133 | * @param blob FDT blob |
| 134 | * @param node node to examine |
Simon Glass | f88fe2d | 2012-02-27 10:52:34 +0000 | [diff] [blame^] | 135 | * @return integer value 0 (not enabled) or 1 (enabled) |
Simon Glass | b5220bc | 2011-10-24 19:15:32 +0000 | [diff] [blame] | 136 | */ |
Simon Glass | f88fe2d | 2012-02-27 10:52:34 +0000 | [diff] [blame^] | 137 | int fdtdec_get_is_enabled(const void *blob, int node); |
Simon Glass | b5220bc | 2011-10-24 19:15:32 +0000 | [diff] [blame] | 138 | |
| 139 | /** |
| 140 | * Checks whether we have a valid fdt available to control U-Boot, and panic |
| 141 | * if not. |
| 142 | */ |
| 143 | int fdtdec_check_fdt(void); |
Simon Glass | a53f4a2 | 2012-01-17 08:20:50 +0000 | [diff] [blame] | 144 | |
| 145 | /** |
| 146 | * Find the nodes for a peripheral and return a list of them in the correct |
| 147 | * order. This is used to enumerate all the peripherals of a certain type. |
| 148 | * |
| 149 | * To use this, optionally set up a /aliases node with alias properties for |
| 150 | * a peripheral. For example, for usb you could have: |
| 151 | * |
| 152 | * aliases { |
| 153 | * usb0 = "/ehci@c5008000"; |
| 154 | * usb1 = "/ehci@c5000000"; |
| 155 | * }; |
| 156 | * |
| 157 | * Pass "usb" as the name to this function and will return a list of two |
| 158 | * nodes offsets: /ehci@c5008000 and ehci@c5000000. |
| 159 | * |
| 160 | * All nodes returned will match the compatible ID, as it is assumed that |
| 161 | * all peripherals use the same driver. |
| 162 | * |
| 163 | * If no alias node is found, then the node list will be returned in the |
| 164 | * order found in the fdt. If the aliases mention a node which doesn't |
| 165 | * exist, then this will be ignored. If nodes are found with no aliases, |
| 166 | * they will be added in any order. |
| 167 | * |
| 168 | * If there is a gap in the aliases, then this function return a 0 node at |
| 169 | * that position. The return value will also count these gaps. |
| 170 | * |
| 171 | * This function checks node properties and will not return nodes which are |
| 172 | * marked disabled (status = "disabled"). |
| 173 | * |
| 174 | * @param blob FDT blob to use |
| 175 | * @param name Root name of alias to search for |
| 176 | * @param id Compatible ID to look for |
| 177 | * @param node_list Place to put list of found nodes |
| 178 | * @param maxcount Maximum number of nodes to find |
| 179 | * @return number of nodes found on success, FTD_ERR_... on error |
| 180 | */ |
| 181 | int fdtdec_find_aliases_for_id(const void *blob, const char *name, |
| 182 | enum fdt_compat_id id, int *node_list, int maxcount); |
| 183 | |
| 184 | /* |
| 185 | * Get the name for a compatible ID |
| 186 | * |
| 187 | * @param id Compatible ID to look for |
| 188 | * @return compatible string for that id |
| 189 | */ |
| 190 | const char *fdtdec_get_compatible(enum fdt_compat_id id); |