xref: /freebsd/sys/dev/bhnd/nvram/bhnd_nvram_if.m (revision 8ef24a0d4b28fe230e20637f56869cc4148cd2ca)
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# $FreeBSD$
26
27#include <sys/types.h>
28#include <sys/bus.h>
29
30#include <dev/bhnd/bhnd.h>
31
32INTERFACE bhnd_nvram;
33
34#
35# bhnd(4) NVRAM device interface.
36#
37# Provides a shared interface to HND NVRAM, OTP, and SPROM devices that provide
38# access to a common set of hardware/device configuration variables.
39#
40
41/**
42 * Read an NVRAM variable.
43 *
44 * @param		dev	The NVRAM device.
45 * @param		name	The NVRAM variable name.
46 * @param[out]		buf	On success, the requested value will be written
47 *				to this buffer. This argment may be NULL if
48 *				the value is not desired.
49 * @param[in,out]	len	The maximum capacity of @p buf. On success,
50 *				will be set to the actual size of the requested
51 *				value.
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 non-zero	If reading @p name otherwise fails, a regular unix
60 *			error code will be returned.
61 */
62METHOD int getvar {
63	device_t	 dev;
64	const char	*name;
65	void		*buf;
66	size_t		*len;
67};
68
69/**
70 * Set an NVRAM variable's local value.
71 *
72 * No changes should be written to non-volatile storage.
73 *
74 * @param	dev	The NVRAM device.
75 * @param	name	The NVRAM variable name.
76 * @param	buf	The new value.
77 * @param	len	The size of @p buf.
78 *
79 * @retval 0		success
80 * @retval ENOENT	The specified variable name is not recognized.
81 * @retval EINVAL	If @p len does not match the expected variable size.
82 * @retval ENODEV	If no supported NVRAM hardware is accessible via this
83 *			device.
84 * @retval non-zero	If reading @p name otherwise fails, a regular unix
85 *			error code will be returned.
86 */
87METHOD int setvar {
88	device_t	 dev;
89	const char	*name;
90	const void	*buf;
91	size_t		 len;
92};
93