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 | /** |
| 85 | * Look up an address property in a node and return it as an address. |
| 86 | * The property must hold either one address with no trailing data or |
| 87 | * one address with a length. This is only tested on 32-bit machines. |
| 88 | * |
| 89 | * @param blob FDT blob |
| 90 | * @param node node to examine |
| 91 | * @param prop_name name of property to find |
| 92 | * @return address, if found, or FDT_ADDR_T_NONE if not |
| 93 | */ |
| 94 | fdt_addr_t fdtdec_get_addr(const void *blob, int node, |
| 95 | const char *prop_name); |
| 96 | |
| 97 | /** |
| 98 | * Look up a 32-bit integer property in a node and return it. The property |
| 99 | * must have at least 4 bytes of data. The value of the first cell is |
| 100 | * returned. |
| 101 | * |
| 102 | * @param blob FDT blob |
| 103 | * @param node node to examine |
| 104 | * @param prop_name name of property to find |
| 105 | * @param default_val default value to return if the property is not found |
| 106 | * @return integer value, if found, or default_val if not |
| 107 | */ |
| 108 | s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, |
| 109 | s32 default_val); |
| 110 | |
| 111 | /** |
| 112 | * Checks whether a node is enabled. |
| 113 | * This looks for a 'status' property. If this exists, then returns 1 if |
| 114 | * the status is 'ok' and 0 otherwise. If there is no status property, |
| 115 | * it returns the default value. |
| 116 | * |
| 117 | * @param blob FDT blob |
| 118 | * @param node node to examine |
| 119 | * @param default_val default value to return if no 'status' property exists |
| 120 | * @return integer value 0/1, if found, or default_val if not |
| 121 | */ |
| 122 | int fdtdec_get_is_enabled(const void *blob, int node, int default_val); |
| 123 | |
| 124 | /** |
| 125 | * Checks whether we have a valid fdt available to control U-Boot, and panic |
| 126 | * if not. |
| 127 | */ |
| 128 | int fdtdec_check_fdt(void); |