summaryrefslogtreecommitdiff
path: root/common/hwconfig.c
blob: e9e956a3223a098386ff6f47d9049da89f44fdf6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
// SPDX-License-Identifier: GPL-2.0+
/*
 * An inteface for configuring a hardware via u-boot environment.
 *
 * Copyright (c) 2009  MontaVista Software, Inc.
 * Copyright 2011 Freescale Semiconductor, Inc.
 *
 * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
 */

#ifndef HWCONFIG_TEST
#include <config.h>
#include <common.h>
#include <exports.h>
#include <hwconfig.h>
#include <linux/types.h>
#include <linux/string.h>
#else
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#define min(a, b) (((a) < (b)) ? (a) : (b))
#endif /* HWCONFIG_TEST */

DECLARE_GLOBAL_DATA_PTR;

static const char *hwconfig_parse(const char *opts, size_t maxlen,
				  const char *opt, char *stopchs, char eqch,
				  size_t *arglen)
{
	size_t optlen = strlen(opt);
	char *str;
	const char *start = opts;
	const char *end;

next:
	str = strstr(opts, opt);
	end = str + optlen;
	if (end - start > maxlen)
		return NULL;

	if (str && (str == opts || strpbrk(str - 1, stopchs) == str - 1) &&
			(strpbrk(end, stopchs) == end || *end == eqch ||
			 *end == '\0')) {
		const char *arg_end;

		if (!arglen)
			return str;

		if (*end != eqch)
			return NULL;

		arg_end = strpbrk(str, stopchs);
		if (!arg_end)
			*arglen = min(maxlen, strlen(str)) - optlen - 1;
		else
			*arglen = arg_end - end - 1;

		return end + 1;
	} else if (str) {
		opts = end;
		goto next;
	}
	return NULL;
}

const char cpu_hwconfig[] __attribute__((weak)) = "";
const char board_hwconfig[] __attribute__((weak)) = "";

static const char *__hwconfig(const char *opt, size_t *arglen,
			      const char *env_hwconfig)
{
	const char *ret;

	/* if we are passed a buffer use it, otherwise try the environment */
	if (!env_hwconfig) {
		if (!(gd->flags & GD_FLG_ENV_READY)) {
			printf("WARNING: Calling __hwconfig without a buffer "
					"and before environment is ready\n");
			return NULL;
		}
		env_hwconfig = env_get("hwconfig");
	}

	if (env_hwconfig) {
		ret = hwconfig_parse(env_hwconfig, strlen(env_hwconfig),
				      opt, ";", ':', arglen);
		if (ret)
			return ret;
	}

	ret = hwconfig_parse(board_hwconfig, strlen(board_hwconfig),
			opt, ";", ':', arglen);
	if (ret)
		return ret;

	return hwconfig_parse(cpu_hwconfig, strlen(cpu_hwconfig),
			opt, ";", ':', arglen);
}

/*
 * hwconfig_f - query if a particular hwconfig option is specified
 * @opt:	a string representing an option
 * @buf:	if non-NULL use this buffer to parse, otherwise try env
 *
 * This call can be used to find out whether U-Boot should configure
 * a particular hardware option.
 *
 * Returns non-zero value if the hardware option can be used and thus
 * should be configured, 0 otherwise.
 *
 * This function also returns non-zero value if CONFIG_HWCONFIG is
 * undefined.
 *
 * Returning non-zero value without CONFIG_HWCONFIG has its crucial
 * purpose: the hwconfig() call should be a "transparent" interface,
 * e.g. if a board doesn't need hwconfig facility, then we assume
 * that the board file only calls things that are actually used, so
 * hwconfig() will always return true result.
 */
int hwconfig_f(const char *opt, char *buf)
{
	return !!__hwconfig(opt, NULL, buf);
}

/*
 * hwconfig_arg_f - get hwconfig option's argument
 * @opt:	a string representing an option
 * @arglen:	a pointer to an allocated size_t variable
 * @buf:	if non-NULL use this buffer to parse, otherwise try env
 *
 * Unlike hwconfig_f() function, this function returns a pointer to the
 * start of the hwconfig arguments, if option is not found or it has
 * no specified arguments, the function returns NULL pointer.
 *
 * If CONFIG_HWCONFIG is undefined, the function returns "", and
 * arglen is set to 0.
 */
const char *hwconfig_arg_f(const char *opt, size_t *arglen, char *buf)
{
	return __hwconfig(opt, arglen, buf);
}

/*
 * hwconfig_arg_cmp_f - compare hwconfig option's argument
 * @opt:	a string representing an option
 * @arg:	a string for comparing an option's argument
 * @buf:	if non-NULL use this buffer to parse, otherwise try env
 *
 * This call is similar to hwconfig_arg_f, but instead of returning
 * hwconfig argument and its length, it is comparing it to @arg.
 *
 * Returns non-zero value if @arg matches, 0 otherwise.
 *
 * If CONFIG_HWCONFIG is undefined, the function returns a non-zero
 * value, i.e. the argument matches.
 */
int hwconfig_arg_cmp_f(const char *opt, const char *arg, char *buf)
{
	const char *argstr;
	size_t arglen;

	argstr = hwconfig_arg_f(opt, &arglen, buf);
	if (!argstr || arglen != strlen(arg))
		return 0;

	return !strncmp(argstr, arg, arglen);
}

/*
 * hwconfig_sub_f - query if a particular hwconfig sub-option is specified
 * @opt:	a string representing an option
 * @subopt:	a string representing a sub-option
 * @buf:	if non-NULL use this buffer to parse, otherwise try env
 *
 * This call is similar to hwconfig_f(), except that it takes additional
 * argument @subopt. In this example:
 * 	"dr_usb:mode=peripheral"
 * "dr_usb" is an option, "mode" is a sub-option, and "peripheral" is its
 * argument.
 */
int hwconfig_sub_f(const char *opt, const char *subopt, char *buf)
{
	size_t arglen;
	const char *arg;

	arg = __hwconfig(opt, &arglen, buf);
	if (!arg)
		return 0;
	return !!hwconfig_parse(arg, arglen, subopt, ",;", '=', NULL);
}

/*
 * hwconfig_subarg_f - get hwconfig sub-option's argument
 * @opt:	a string representing an option
 * @subopt:	a string representing a sub-option
 * @subarglen:	a pointer to an allocated size_t variable
 * @buf:	if non-NULL use this buffer to parse, otherwise try env
 *
 * This call is similar to hwconfig_arg_f(), except that it takes an
 * additional argument @subopt, and so works with sub-options.
 */
const char *hwconfig_subarg_f(const char *opt, const char *subopt,
			      size_t *subarglen, char *buf)
{
	size_t arglen;
	const char *arg;

	arg = __hwconfig(opt, &arglen, buf);
	if (!arg)
		return NULL;
	return hwconfig_parse(arg, arglen, subopt, ",;", '=', subarglen);
}

/*
 * hwconfig_arg_cmp_f - compare hwconfig sub-option's argument
 * @opt:	a string representing an option
 * @subopt:	a string representing a sub-option
 * @subarg:	a string for comparing an sub-option's argument
 * @buf:	if non-NULL use this buffer to parse, otherwise try env
 *
 * This call is similar to hwconfig_arg_cmp_f, except that it takes an
 * additional argument @subopt, and so works with sub-options.
 */
int hwconfig_subarg_cmp_f(const char *opt, const char *subopt,
			  const char *subarg, char *buf)
{
	const char *argstr;
	size_t arglen;

	argstr = hwconfig_subarg_f(opt, subopt, &arglen, buf);
	if (!argstr || arglen != strlen(subarg))
		return 0;

	return !strncmp(argstr, subarg, arglen);
}

#ifdef HWCONFIG_TEST
int main()
{
	const char *ret;
	size_t len;

	env_set("hwconfig", "key1:subkey1=value1,subkey2=value2;key2:value3;;;;"
			   "key3;:,:=;key4", 1);

	ret = hwconfig_arg("key1", &len);
	printf("%zd %.*s\n", len, (int)len, ret);
	assert(len == 29);
	assert(hwconfig_arg_cmp("key1", "subkey1=value1,subkey2=value2"));
	assert(!strncmp(ret, "subkey1=value1,subkey2=value2", len));

	ret = hwconfig_subarg("key1", "subkey1", &len);
	printf("%zd %.*s\n", len, (int)len, ret);
	assert(len == 6);
	assert(hwconfig_subarg_cmp("key1", "subkey1", "value1"));
	assert(!strncmp(ret, "value1", len));

	ret = hwconfig_subarg("key1", "subkey2", &len);
	printf("%zd %.*s\n", len, (int)len, ret);
	assert(len == 6);
	assert(hwconfig_subarg_cmp("key1", "subkey2", "value2"));
	assert(!strncmp(ret, "value2", len));

	ret = hwconfig_arg("key2", &len);
	printf("%zd %.*s\n", len, (int)len, ret);
	assert(len == 6);
	assert(hwconfig_arg_cmp("key2", "value3"));
	assert(!strncmp(ret, "value3", len));

	assert(hwconfig("key3"));
	assert(hwconfig_arg("key4", &len) == NULL);
	assert(hwconfig_arg("bogus", &len) == NULL);

	unenv_set("hwconfig");

	assert(hwconfig(NULL) == 0);
	assert(hwconfig("") == 0);
	assert(hwconfig("key3") == 0);

	return 0;
}
#endif /* HWCONFIG_TEST */