1 /* 2 * An inteface for configuring a hardware via u-boot environment. 3 * 4 * Copyright (c) 2009 MontaVista Software, Inc. 5 * Copyright 2011 Freescale Semiconductor, Inc. 6 * 7 * Author: Anton Vorontsov <avorontsov@ru.mvista.com> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License as 11 * published by the Free Software Foundation; either version 2 of 12 * the License, or (at your option) any later version. 13 */ 14 15 #ifndef HWCONFIG_TEST 16 #include <config.h> 17 #include <common.h> 18 #include <exports.h> 19 #include <hwconfig.h> 20 #include <linux/types.h> 21 #include <linux/string.h> 22 #else 23 #include <stdio.h> 24 #include <stdlib.h> 25 #include <string.h> 26 #include <assert.h> 27 #define min(a, b) (((a) < (b)) ? (a) : (b)) 28 #endif /* HWCONFIG_TEST */ 29 30 DECLARE_GLOBAL_DATA_PTR; 31 32 static const char *hwconfig_parse(const char *opts, size_t maxlen, 33 const char *opt, char *stopchs, char eqch, 34 size_t *arglen) 35 { 36 size_t optlen = strlen(opt); 37 char *str; 38 const char *start = opts; 39 const char *end; 40 41 next: 42 str = strstr(opts, opt); 43 end = str + optlen; 44 if (end - start > maxlen) 45 return NULL; 46 47 if (str && (str == opts || strpbrk(str - 1, stopchs) == str - 1) && 48 (strpbrk(end, stopchs) == end || *end == eqch || 49 *end == '\0')) { 50 const char *arg_end; 51 52 if (!arglen) 53 return str; 54 55 if (*end != eqch) 56 return NULL; 57 58 arg_end = strpbrk(str, stopchs); 59 if (!arg_end) 60 *arglen = min(maxlen, strlen(str)) - optlen - 1; 61 else 62 *arglen = arg_end - end - 1; 63 64 return end + 1; 65 } else if (str) { 66 opts = end; 67 goto next; 68 } 69 return NULL; 70 } 71 72 const char cpu_hwconfig[] __attribute__((weak)) = ""; 73 const char board_hwconfig[] __attribute__((weak)) = ""; 74 75 static const char *__hwconfig(const char *opt, size_t *arglen, 76 const char *env_hwconfig) 77 { 78 const char *ret; 79 80 /* if we are passed a buffer use it, otherwise try the environment */ 81 if (!env_hwconfig) { 82 if (!(gd->flags & GD_FLG_ENV_READY)) { 83 printf("WARNING: Calling __hwconfig without a buffer " 84 "and before environment is ready\n"); 85 return NULL; 86 } 87 env_hwconfig = getenv("hwconfig"); 88 } 89 90 if (env_hwconfig) { 91 ret = hwconfig_parse(env_hwconfig, strlen(env_hwconfig), 92 opt, ";", ':', arglen); 93 if (ret) 94 return ret; 95 } 96 97 ret = hwconfig_parse(board_hwconfig, strlen(board_hwconfig), 98 opt, ";", ':', arglen); 99 if (ret) 100 return ret; 101 102 return hwconfig_parse(cpu_hwconfig, strlen(cpu_hwconfig), 103 opt, ";", ':', arglen); 104 } 105 106 /* 107 * hwconfig_f - query if a particular hwconfig option is specified 108 * @opt: a string representing an option 109 * @buf: if non-NULL use this buffer to parse, otherwise try env 110 * 111 * This call can be used to find out whether U-Boot should configure 112 * a particular hardware option. 113 * 114 * Returns non-zero value if the hardware option can be used and thus 115 * should be configured, 0 otherwise. 116 * 117 * This function also returns non-zero value if CONFIG_HWCONFIG is 118 * undefined. 119 * 120 * Returning non-zero value without CONFIG_HWCONFIG has its crucial 121 * purpose: the hwconfig() call should be a "transparent" interface, 122 * e.g. if a board doesn't need hwconfig facility, then we assume 123 * that the board file only calls things that are actually used, so 124 * hwconfig() will always return true result. 125 */ 126 int hwconfig_f(const char *opt, char *buf) 127 { 128 return !!__hwconfig(opt, NULL, buf); 129 } 130 131 /* 132 * hwconfig_arg_f - get hwconfig option's argument 133 * @opt: a string representing an option 134 * @arglen: a pointer to an allocated size_t variable 135 * @buf: if non-NULL use this buffer to parse, otherwise try env 136 * 137 * Unlike hwconfig_f() function, this function returns a pointer to the 138 * start of the hwconfig arguments, if option is not found or it has 139 * no specified arguments, the function returns NULL pointer. 140 * 141 * If CONFIG_HWCONFIG is undefined, the function returns "", and 142 * arglen is set to 0. 143 */ 144 const char *hwconfig_arg_f(const char *opt, size_t *arglen, char *buf) 145 { 146 return __hwconfig(opt, arglen, buf); 147 } 148 149 /* 150 * hwconfig_arg_cmp_f - compare hwconfig option's argument 151 * @opt: a string representing an option 152 * @arg: a string for comparing an option's argument 153 * @buf: if non-NULL use this buffer to parse, otherwise try env 154 * 155 * This call is similar to hwconfig_arg_f, but instead of returning 156 * hwconfig argument and its length, it is comparing it to @arg. 157 * 158 * Returns non-zero value if @arg matches, 0 otherwise. 159 * 160 * If CONFIG_HWCONFIG is undefined, the function returns a non-zero 161 * value, i.e. the argument matches. 162 */ 163 int hwconfig_arg_cmp_f(const char *opt, const char *arg, char *buf) 164 { 165 const char *argstr; 166 size_t arglen; 167 168 argstr = hwconfig_arg_f(opt, &arglen, buf); 169 if (!argstr || arglen != strlen(arg)) 170 return 0; 171 172 return !strncmp(argstr, arg, arglen); 173 } 174 175 /* 176 * hwconfig_sub_f - query if a particular hwconfig sub-option is specified 177 * @opt: a string representing an option 178 * @subopt: a string representing a sub-option 179 * @buf: if non-NULL use this buffer to parse, otherwise try env 180 * 181 * This call is similar to hwconfig_f(), 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 */ 187 int hwconfig_sub_f(const char *opt, const char *subopt, char *buf) 188 { 189 size_t arglen; 190 const char *arg; 191 192 arg = __hwconfig(opt, &arglen, buf); 193 if (!arg) 194 return 0; 195 return !!hwconfig_parse(arg, arglen, subopt, ",;", '=', NULL); 196 } 197 198 /* 199 * hwconfig_subarg_f - 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 * @buf: if non-NULL use this buffer to parse, otherwise try env 204 * 205 * This call is similar to hwconfig_arg_f(), except that it takes an 206 * additional argument @subopt, and so works with sub-options. 207 */ 208 const char *hwconfig_subarg_f(const char *opt, const char *subopt, 209 size_t *subarglen, char *buf) 210 { 211 size_t arglen; 212 const char *arg; 213 214 arg = __hwconfig(opt, &arglen, buf); 215 if (!arg) 216 return NULL; 217 return hwconfig_parse(arg, arglen, subopt, ",;", '=', subarglen); 218 } 219 220 /* 221 * hwconfig_arg_cmp_f - compare hwconfig sub-option's argument 222 * @opt: a string representing an option 223 * @subopt: a string representing a sub-option 224 * @subarg: a string for comparing an sub-option's argument 225 * @buf: if non-NULL use this buffer to parse, otherwise try env 226 * 227 * This call is similar to hwconfig_arg_cmp_f, except that it takes an 228 * additional argument @subopt, and so works with sub-options. 229 */ 230 int hwconfig_subarg_cmp_f(const char *opt, const char *subopt, 231 const char *subarg, char *buf) 232 { 233 const char *argstr; 234 size_t arglen; 235 236 argstr = hwconfig_subarg_f(opt, subopt, &arglen, buf); 237 if (!argstr || arglen != strlen(subarg)) 238 return 0; 239 240 return !strncmp(argstr, subarg, arglen); 241 } 242 243 #ifdef HWCONFIG_TEST 244 int main() 245 { 246 const char *ret; 247 size_t len; 248 249 setenv("hwconfig", "key1:subkey1=value1,subkey2=value2;key2:value3;;;;" 250 "key3;:,:=;key4", 1); 251 252 ret = hwconfig_arg("key1", &len); 253 printf("%zd %.*s\n", len, (int)len, ret); 254 assert(len == 29); 255 assert(hwconfig_arg_cmp("key1", "subkey1=value1,subkey2=value2")); 256 assert(!strncmp(ret, "subkey1=value1,subkey2=value2", len)); 257 258 ret = hwconfig_subarg("key1", "subkey1", &len); 259 printf("%zd %.*s\n", len, (int)len, ret); 260 assert(len == 6); 261 assert(hwconfig_subarg_cmp("key1", "subkey1", "value1")); 262 assert(!strncmp(ret, "value1", len)); 263 264 ret = hwconfig_subarg("key1", "subkey2", &len); 265 printf("%zd %.*s\n", len, (int)len, ret); 266 assert(len == 6); 267 assert(hwconfig_subarg_cmp("key1", "subkey2", "value2")); 268 assert(!strncmp(ret, "value2", len)); 269 270 ret = hwconfig_arg("key2", &len); 271 printf("%zd %.*s\n", len, (int)len, ret); 272 assert(len == 6); 273 assert(hwconfig_arg_cmp("key2", "value3")); 274 assert(!strncmp(ret, "value3", len)); 275 276 assert(hwconfig("key3")); 277 assert(hwconfig_arg("key4", &len) == NULL); 278 assert(hwconfig_arg("bogus", &len) == NULL); 279 280 unsetenv("hwconfig"); 281 282 assert(hwconfig(NULL) == 0); 283 assert(hwconfig("") == 0); 284 assert(hwconfig("key3") == 0); 285 286 return 0; 287 } 288 #endif /* HWCONFIG_TEST */ 289