blob: e5c60ba7a40a415d5bf10447f697336affd24058 [file] [log] [blame]
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +04001/*
2 * An inteface for configuring a hardware via u-boot environment.
3 *
4 * Copyright (c) 2009 MontaVista Software, Inc.
5 *
6 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 */
13
14#include <config.h>
15#include <common.h>
16#include <exports.h>
17#include <hwconfig.h>
18#include <linux/types.h>
19#include <linux/string.h>
20
21static const char *hwconfig_parse(const char *opts, size_t maxlen,
22 const char *opt, char stopch, char eqch,
23 size_t *arglen)
24{
25 size_t optlen = strlen(opt);
26 char *str;
27 const char *start = opts;
28 const char *end;
29
30next:
31 str = strstr(opts, opt);
32 end = str + optlen;
33 if (end - start > maxlen)
34 return NULL;
35
36 if (str && (str == opts || str[-1] == stopch) &&
37 (*end == stopch || *end == eqch || *end == '\0')) {
38 const char *arg_end;
39
40 if (!arglen)
41 return str;
42
43 if (*end != eqch)
44 return NULL;
45
46 arg_end = strchr(str, stopch);
47 if (!arg_end)
48 *arglen = min(maxlen, strlen(str)) - optlen - 1;
49 else
50 *arglen = arg_end - end - 1;
51
52 return end + 1;
53 } else if (str) {
54 opts = end;
55 goto next;
56 }
57 return NULL;
58}
59
60const char *cpu_hwconfig __attribute__((weak));
61const char *board_hwconfig __attribute__((weak));
62
63static const char *__hwconfig(const char *opt, size_t *arglen)
64{
65 const char *env_hwconfig = getenv("hwconfig");
66
67 if (env_hwconfig)
68 return hwconfig_parse(env_hwconfig, strlen(env_hwconfig),
69 opt, ';', ':', arglen);
70
71 if (board_hwconfig)
72 return hwconfig_parse(board_hwconfig, strlen(board_hwconfig),
73 opt, ';', ':', arglen);
74
75 if (cpu_hwconfig)
76 return hwconfig_parse(cpu_hwconfig, strlen(cpu_hwconfig),
77 opt, ';', ':', arglen);
78
79 return NULL;
80}
81
82/*
83 * hwconfig - query if a particular hwconfig option is specified
84 * @opt: a string representing an option
85 *
86 * This call can be used to find out whether U-Boot should configure
87 * a particular hardware option.
88 *
89 * Returns non-zero value if the hardware option can be used and thus
90 * should be configured, 0 otherwise.
91 *
92 * This function also returns non-zero value if CONFIG_HWCONFIG is
93 * undefined.
94 *
95 * Returning non-zero value without CONFIG_HWCONFIG has its crucial
96 * purpose: the hwconfig() call should be a "transparent" interface,
97 * e.g. if a board doesn't need hwconfig facility, then we assume
98 * that the board file only calls things that are actually used, so
99 * hwconfig() will always return true result.
100 */
101int hwconfig(const char *opt)
102{
103 return !!__hwconfig(opt, NULL);
104}
105
106/*
107 * hwconfig_arg - get hwconfig option's argument
108 * @opt: a string representing an option
109 * @arglen: a pointer to an allocated size_t variable
110 *
111 * Unlike hwconfig() function, this function returns a pointer to the
112 * start of the hwconfig arguments, if option is not found or it has
113 * no specified arguments, the function returns NULL pointer.
114 *
115 * If CONFIG_HWCONFIG is undefined, the function returns "", and
116 * arglen is set to 0.
117 */
118const char *hwconfig_arg(const char *opt, size_t *arglen)
119{
120 return __hwconfig(opt, arglen);
121}
122
123/*
124 * hwconfig_arg_cmp - compare hwconfig option's argument
125 * @opt: a string representing an option
126 * @arg: a string for comparing an option's argument
127 *
128 * This call is similar to hwconfig_arg, but instead of returning
129 * hwconfig argument and its length, it is comparing it to @arg.
130 *
131 * Returns non-zero value if @arg matches, 0 otherwise.
132 *
133 * If CONFIG_HWCONFIG is undefined, the function returns a non-zero
134 * value, i.e. the argument matches.
135 */
136int hwconfig_arg_cmp(const char *opt, const char *arg)
137{
138 const char *argstr;
139 size_t arglen;
140
141 argstr = hwconfig_arg(opt, &arglen);
142 if (!argstr || arglen != strlen(arg))
143 return 0;
144
145 return !strncmp(argstr, arg, arglen);
146}
147
148/*
149 * hwconfig_sub - query if a particular hwconfig sub-option is specified
150 * @opt: a string representing an option
151 * @subopt: a string representing a sub-option
152 *
153 * This call is similar to hwconfig(), except that it takes additional
154 * argument @subopt. In this example:
155 * "dr_usb:mode=peripheral"
156 * "dr_usb" is an option, "mode" is a sub-option, and "peripheral" is its
157 * argument.
158 */
159int hwconfig_sub(const char *opt, const char *subopt)
160{
161 size_t arglen;
162 const char *arg;
163
164 arg = __hwconfig(opt, &arglen);
165 if (!arg)
166 return 0;
167 return !!hwconfig_parse(arg, arglen, subopt, ',', '=', NULL);
168}
169
170/*
171 * hwconfig_subarg - get hwconfig sub-option's argument
172 * @opt: a string representing an option
173 * @subopt: a string representing a sub-option
174 * @subarglen: a pointer to an allocated size_t variable
175 *
176 * This call is similar to hwconfig_arg(), except that it takes an additional
177 * argument @subopt, and so works with sub-options.
178 */
179const char *hwconfig_subarg(const char *opt, const char *subopt,
180 size_t *subarglen)
181{
182 size_t arglen;
183 const char *arg;
184
185 arg = __hwconfig(opt, &arglen);
186 if (!arg)
187 return NULL;
188 return hwconfig_parse(arg, arglen, subopt, ',', '=', subarglen);
189}
190
191/*
192 * hwconfig_arg_cmp - compare hwconfig sub-option's argument
193 * @opt: a string representing an option
194 * @subopt: a string representing a sub-option
195 * @subarg: a string for comparing an sub-option's argument
196 *
197 * This call is similar to hwconfig_arg_cmp, except that it takes an additional
198 * argument @subopt, and so works with sub-options.
199 */
200int hwconfig_subarg_cmp(const char *opt, const char *subopt, const char *subarg)
201{
202 const char *argstr;
203 size_t arglen;
204
205 argstr = hwconfig_subarg(opt, subopt, &arglen);
206 if (!argstr || arglen != strlen(subarg))
207 return 0;
208
209 return !strncmp(argstr, subarg, arglen);
210}