[people/ms/u-boot.git] / include / fdtdec.h

/*
 * 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);
Commit	Line	Data
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,
	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);