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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
Anton Vorontsov3bf74a42010-06-18 15:08:27 +040014#ifndef HWCONFIG_TEST
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +040015#include <config.h>
16#include <common.h>
17#include <exports.h>
18#include <hwconfig.h>
19#include <linux/types.h>
20#include <linux/string.h>
Anton Vorontsov3bf74a42010-06-18 15:08:27 +040021#else
22#include <stdio.h>
23#include <stdlib.h>
24#include <string.h>
25#include <assert.h>
26#define min(a, b) (((a) < (b)) ? (a) : (b))
27#endif /* HWCONFIG_TEST */
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +040028
Kumar Galac4b115f2010-10-22 03:18:13 -050029DECLARE_GLOBAL_DATA_PTR;
30
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +040031static const char *hwconfig_parse(const char *opts, size_t maxlen,
Anton Vorontsov81f8d3b2010-06-18 15:08:12 +040032 const char *opt, char *stopchs, char eqch,
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +040033 size_t *arglen)
34{
35 size_t optlen = strlen(opt);
36 char *str;
37 const char *start = opts;
38 const char *end;
39
40next:
41 str = strstr(opts, opt);
42 end = str + optlen;
43 if (end - start > maxlen)
44 return NULL;
45
Anton Vorontsov81f8d3b2010-06-18 15:08:12 +040046 if (str && (str == opts || strpbrk(str - 1, stopchs) == str - 1) &&
47 (strpbrk(end, stopchs) == end || *end == eqch ||
48 *end == '\0')) {
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +040049 const char *arg_end;
50
51 if (!arglen)
52 return str;
53
54 if (*end != eqch)
55 return NULL;
56
Anton Vorontsov81f8d3b2010-06-18 15:08:12 +040057 arg_end = strpbrk(str, stopchs);
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +040058 if (!arg_end)
59 *arglen = min(maxlen, strlen(str)) - optlen - 1;
60 else
61 *arglen = arg_end - end - 1;
62
63 return end + 1;
64 } else if (str) {
65 opts = end;
66 goto next;
67 }
68 return NULL;
69}
70
71const char *cpu_hwconfig __attribute__((weak));
72const char *board_hwconfig __attribute__((weak));
73
Kumar Galac4b115f2010-10-22 03:18:13 -050074#define HWCONFIG_PRE_RELOC_BUF_SIZE 128
75
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +040076static const char *__hwconfig(const char *opt, size_t *arglen)
77{
Kumar Galac4b115f2010-10-22 03:18:13 -050078 const char *env_hwconfig = NULL;
79 char buf[HWCONFIG_PRE_RELOC_BUF_SIZE];
80
81 if (gd->flags & GD_FLG_ENV_READY) {
82 env_hwconfig = getenv("hwconfig");
83 } else {
84 /*
85 * Use our own on stack based buffer before relocation to allow
86 * accessing longer hwconfig strings that might be in the
87 * environment before we've relocated. This is pretty fragile
88 * on both the use of stack and if the buffer is big enough.
89 * However we will get a warning from getenv_f for the later.
90 */
91 if ((getenv_f("hwconfig", buf, sizeof(buf))) > 0)
92 env_hwconfig = buf;
93 }
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +040094
95 if (env_hwconfig)
96 return hwconfig_parse(env_hwconfig, strlen(env_hwconfig),
Anton Vorontsov81f8d3b2010-06-18 15:08:12 +040097 opt, ";", ':', arglen);
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +040098
99 if (board_hwconfig)
100 return hwconfig_parse(board_hwconfig, strlen(board_hwconfig),
Anton Vorontsov81f8d3b2010-06-18 15:08:12 +0400101 opt, ";", ':', arglen);
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +0400102
103 if (cpu_hwconfig)
104 return hwconfig_parse(cpu_hwconfig, strlen(cpu_hwconfig),
Anton Vorontsov81f8d3b2010-06-18 15:08:12 +0400105 opt, ";", ':', arglen);
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +0400106
107 return NULL;
108}
109
110/*
111 * hwconfig - query if a particular hwconfig option is specified
112 * @opt: a string representing an option
113 *
114 * This call can be used to find out whether U-Boot should configure
115 * a particular hardware option.
116 *
117 * Returns non-zero value if the hardware option can be used and thus
118 * should be configured, 0 otherwise.
119 *
120 * This function also returns non-zero value if CONFIG_HWCONFIG is
121 * undefined.
122 *
123 * Returning non-zero value without CONFIG_HWCONFIG has its crucial
124 * purpose: the hwconfig() call should be a "transparent" interface,
125 * e.g. if a board doesn't need hwconfig facility, then we assume
126 * that the board file only calls things that are actually used, so
127 * hwconfig() will always return true result.
128 */
129int hwconfig(const char *opt)
130{
131 return !!__hwconfig(opt, NULL);
132}
133
134/*
135 * hwconfig_arg - get hwconfig option's argument
136 * @opt: a string representing an option
137 * @arglen: a pointer to an allocated size_t variable
138 *
139 * Unlike hwconfig() function, this function returns a pointer to the
140 * start of the hwconfig arguments, if option is not found or it has
141 * no specified arguments, the function returns NULL pointer.
142 *
143 * If CONFIG_HWCONFIG is undefined, the function returns "", and
144 * arglen is set to 0.
145 */
146const char *hwconfig_arg(const char *opt, size_t *arglen)
147{
148 return __hwconfig(opt, arglen);
149}
150
151/*
152 * hwconfig_arg_cmp - compare hwconfig option's argument
153 * @opt: a string representing an option
154 * @arg: a string for comparing an option's argument
155 *
156 * This call is similar to hwconfig_arg, but instead of returning
157 * hwconfig argument and its length, it is comparing it to @arg.
158 *
159 * Returns non-zero value if @arg matches, 0 otherwise.
160 *
161 * If CONFIG_HWCONFIG is undefined, the function returns a non-zero
162 * value, i.e. the argument matches.
163 */
164int hwconfig_arg_cmp(const char *opt, const char *arg)
165{
166 const char *argstr;
167 size_t arglen;
168
169 argstr = hwconfig_arg(opt, &arglen);
170 if (!argstr || arglen != strlen(arg))
171 return 0;
172
173 return !strncmp(argstr, arg, arglen);
174}
175
176/*
177 * hwconfig_sub - query if a particular hwconfig sub-option is specified
178 * @opt: a string representing an option
179 * @subopt: a string representing a sub-option
180 *
181 * This call is similar to hwconfig(), except that it takes additional
182 * argument @subopt. In this example:
183 * "dr_usb:mode=peripheral"
184 * "dr_usb" is an option, "mode" is a sub-option, and "peripheral" is its
185 * argument.
186 */
187int hwconfig_sub(const char *opt, const char *subopt)
188{
189 size_t arglen;
190 const char *arg;
191
192 arg = __hwconfig(opt, &arglen);
193 if (!arg)
194 return 0;
Anton Vorontsov81f8d3b2010-06-18 15:08:12 +0400195 return !!hwconfig_parse(arg, arglen, subopt, ",;", '=', NULL);
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +0400196}
197
198/*
199 * hwconfig_subarg - get hwconfig sub-option's argument
200 * @opt: a string representing an option
201 * @subopt: a string representing a sub-option
202 * @subarglen: a pointer to an allocated size_t variable
203 *
204 * This call is similar to hwconfig_arg(), except that it takes an additional
205 * argument @subopt, and so works with sub-options.
206 */
207const char *hwconfig_subarg(const char *opt, const char *subopt,
208 size_t *subarglen)
209{
210 size_t arglen;
211 const char *arg;
212
213 arg = __hwconfig(opt, &arglen);
214 if (!arg)
215 return NULL;
Anton Vorontsov81f8d3b2010-06-18 15:08:12 +0400216 return hwconfig_parse(arg, arglen, subopt, ",;", '=', subarglen);
Anton Vorontsov93f9dcf2009-06-10 00:25:27 +0400217}
218
219/*
220 * hwconfig_arg_cmp - compare hwconfig sub-option's argument
221 * @opt: a string representing an option
222 * @subopt: a string representing a sub-option
223 * @subarg: a string for comparing an sub-option's argument
224 *
225 * This call is similar to hwconfig_arg_cmp, except that it takes an additional
226 * argument @subopt, and so works with sub-options.
227 */
228int hwconfig_subarg_cmp(const char *opt, const char *subopt, const char *subarg)
229{
230 const char *argstr;
231 size_t arglen;
232
233 argstr = hwconfig_subarg(opt, subopt, &arglen);
234 if (!argstr || arglen != strlen(subarg))
235 return 0;
236
237 return !strncmp(argstr, subarg, arglen);
238}
Anton Vorontsov3bf74a42010-06-18 15:08:27 +0400239
240#ifdef HWCONFIG_TEST
241int main()
242{
243 const char *ret;
244 size_t len;
245
246 setenv("hwconfig", "key1:subkey1=value1,subkey2=value2;key2:value3;;;;"
247 "key3;:,:=;key4", 1);
248
249 ret = hwconfig_arg("key1", &len);
250 printf("%zd %.*s\n", len, (int)len, ret);
251 assert(len == 29);
252 assert(hwconfig_arg_cmp("key1", "subkey1=value1,subkey2=value2"));
253 assert(!strncmp(ret, "subkey1=value1,subkey2=value2", len));
254
255 ret = hwconfig_subarg("key1", "subkey1", &len);
256 printf("%zd %.*s\n", len, (int)len, ret);
257 assert(len == 6);
258 assert(hwconfig_subarg_cmp("key1", "subkey1", "value1"));
259 assert(!strncmp(ret, "value1", len));
260
261 ret = hwconfig_subarg("key1", "subkey2", &len);
262 printf("%zd %.*s\n", len, (int)len, ret);
263 assert(len == 6);
264 assert(hwconfig_subarg_cmp("key1", "subkey2", "value2"));
265 assert(!strncmp(ret, "value2", len));
266
267 ret = hwconfig_arg("key2", &len);
268 printf("%zd %.*s\n", len, (int)len, ret);
269 assert(len == 6);
270 assert(hwconfig_arg_cmp("key2", "value3"));
271 assert(!strncmp(ret, "value3", len));
272
273 assert(hwconfig("key3"));
274 assert(hwconfig_arg("key4", &len) == NULL);
275 assert(hwconfig_arg("bogus", &len) == NULL);
276
277 unsetenv("hwconfig");
278
279 assert(hwconfig(NULL) == 0);
280 assert(hwconfig("") == 0);
281 assert(hwconfig("key3") == 0);
282
283 return 0;
284}
285#endif /* HWCONFIG_TEST */