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/*
* 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);
/**
* 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);
/*
* 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);
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