/* * 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 */ /* * 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) #else typedef u32 fdt_addr_t; #define FDT_ADDR_T_NONE (-1U) #define fdt_addr_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_COUNT, }; /** * 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); /** * 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); /** * 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 the default value. * * @param blob FDT blob * @param node node to examine * @param default_val default value to return if no 'status' property exists * @return integer value 0/1, if found, or default_val if not */ int fdtdec_get_is_enabled(const void *blob, int node, int default_val); /** * Checks whether we have a valid fdt available to control U-Boot, and panic * if not. */ int fdtdec_check_fdt(void);