xref: /freebsd/sys/dev/bhnd/nvram/bhnd_nvram_if.m (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
1#-
2# Copyright (c) 2016 Landon Fuller <landon@landonf.org>
3# All rights reserved.
4#
5# Redistribution and use in source and binary forms, with or without
6# modification, are permitted provided that the following conditions
7# are met:
8# 1. Redistributions of source code must retain the above copyright
9#    notice, this list of conditions and the following disclaimer.
10# 2. Redistributions in binary form must reproduce the above copyright
11#    notice, this list of conditions and the following disclaimer in the
12#    documentation and/or other materials provided with the distribution.
13#
14# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17# IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
18# INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
20# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
21# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
22# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
23# USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24#
25
26#include <sys/types.h>
27#include <sys/bus.h>
28
29#include <dev/bhnd/bhnd.h>
30
31INTERFACE bhnd_nvram;
32
33#
34# bhnd(4) NVRAM device interface.
35#
36# Provides a shared interface to HND NVRAM, OTP, and SPROM devices that provide
37# access to a common set of hardware/device configuration variables.
38#
39
40/**
41 * Read an NVRAM variable.
42 *
43 * @param		dev	The NVRAM device.
44 * @param		name	The NVRAM variable name.
45 * @param[out]		buf	On success, the requested value will be written
46 *				to this buffer. This argment may be NULL if
47 *				the value is not desired.
48 * @param[in,out]	len	The maximum capacity of @p buf. On success,
49 *				will be set to the actual size of the requested
50 *				value.
51 * @param		type	The data type to be written to @p buf.
52 *
53 * @retval 0		success
54 * @retval ENOENT	The requested variable was not found.
55 * @retval ENOMEM	If @p buf is non-NULL and a buffer of @p len is too
56 *			small to hold the requested value.
57 * @retval ENODEV	If no supported NVRAM hardware is accessible via this
58 *			device.
59 * @retval EOPNOTSUPP	If any coercion to @p type is unsupported.
60 * @retval EFTYPE	If the @p name's data type cannot be coerced to @p type.
61 * @retval ERANGE	If value coercion would overflow @p type.
62 * @retval non-zero	If reading @p name otherwise fails, a regular unix
63 *			error code will be returned.
64 */
65METHOD int getvar {
66	device_t	 dev;
67	const char	*name;
68	void		*buf;
69	size_t		*len;
70	bhnd_nvram_type	 type;
71};
72
73/**
74 * Set an NVRAM variable's value.
75 *
76 * No changes will be written to non-volatile storage until explicitly
77 * committed.
78 *
79 * @param	dev	The NVRAM device.
80 * @param	name	The NVRAM variable name.
81 * @param	value	The new value.
82 * @param	len	The size of @p value.
83 * @param	type	The data type of @p value.
84 *
85 * @retval 0		success
86 * @retval ENOENT	The specified variable name is not recognized.
87 * @retval ENODEV	If no supported NVRAM hardware is accessible via this
88 *			device.
89 * @retval EOPNOTSUPP	If any coercion to @p type is unsupported.
90 * @retval EFTYPE	If the @p name's data type cannot be coerced to @p type.
91 * @retval ERANGE	If value coercion from  @p type would overflow.
92 * @retval non-zero	If reading @p name otherwise fails, a regular unix
93 *			error code will be returned.
94 */
95METHOD int setvar {
96	device_t	 dev;
97	const char	*name;
98	const void	*value;
99	size_t		 len;
100	bhnd_nvram_type	 type;
101};
102