1 /* 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 #ifndef HWCONFIG_TEST 15 #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> 21 #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 */ 28 29 static const char *hwconfig_parse(const char *opts, size_t maxlen, 30 const char *opt, char *stopchs, char eqch, 31 size_t *arglen) 32 { 33 size_t optlen = strlen(opt); 34 char *str; 35 const char *start = opts; 36 const char *end; 37 38 next: 39 str = strstr(opts, opt); 40 end = str + optlen; 41 if (end - start > maxlen) 42 return NULL; 43 44 if (str && (str == opts || strpbrk(str - 1, stopchs) == str - 1) && 45 (strpbrk(end, stopchs) == end || *end == eqch || 46 *end == '\0')) { 47 const char *arg_end; 48 49 if (!arglen) 50 return str; 51 52 if (*end != eqch) 53 return NULL; 54 55 arg_end = strpbrk(str, stopchs); 56 if (!arg_end) 57 *arglen = min(maxlen, strlen(str)) - optlen - 1; 58 else 59 *arglen = arg_end - end - 1; 60 61 return end + 1; 62 } else if (str) { 63 opts = end; 64 goto next; 65 } 66 return NULL; 67 } 68 69 const char *cpu_hwconfig __attribute__((weak)); 70 const char *board_hwconfig __attribute__((weak)); 71 72 static const char *__hwconfig(const char *opt, size_t *arglen) 73 { 74 const char *env_hwconfig = getenv("hwconfig"); 75 76 if (env_hwconfig) 77 return hwconfig_parse(env_hwconfig, strlen(env_hwconfig), 78 opt, ";", ':', arglen); 79 80 if (board_hwconfig) 81 return hwconfig_parse(board_hwconfig, strlen(board_hwconfig), 82 opt, ";", ':', arglen); 83 84 if (cpu_hwconfig) 85 return hwconfig_parse(cpu_hwconfig, strlen(cpu_hwconfig), 86 opt, ";", ':', arglen); 87 88 return NULL; 89 } 90 91 /* 92 * hwconfig - query if a particular hwconfig option is specified 93 * @opt: a string representing an option 94 * 95 * This call can be used to find out whether U-Boot should configure 96 * a particular hardware option. 97 * 98 * Returns non-zero value if the hardware option can be used and thus 99 * should be configured, 0 otherwise. 100 * 101 * This function also returns non-zero value if CONFIG_HWCONFIG is 102 * undefined. 103 * 104 * Returning non-zero value without CONFIG_HWCONFIG has its crucial 105 * purpose: the hwconfig() call should be a "transparent" interface, 106 * e.g. if a board doesn't need hwconfig facility, then we assume 107 * that the board file only calls things that are actually used, so 108 * hwconfig() will always return true result. 109 */ 110 int hwconfig(const char *opt) 111 { 112 return !!__hwconfig(opt, NULL); 113 } 114 115 /* 116 * hwconfig_arg - get hwconfig option's argument 117 * @opt: a string representing an option 118 * @arglen: a pointer to an allocated size_t variable 119 * 120 * Unlike hwconfig() function, this function returns a pointer to the 121 * start of the hwconfig arguments, if option is not found or it has 122 * no specified arguments, the function returns NULL pointer. 123 * 124 * If CONFIG_HWCONFIG is undefined, the function returns "", and 125 * arglen is set to 0. 126 */ 127 const char *hwconfig_arg(const char *opt, size_t *arglen) 128 { 129 return __hwconfig(opt, arglen); 130 } 131 132 /* 133 * hwconfig_arg_cmp - compare hwconfig option's argument 134 * @opt: a string representing an option 135 * @arg: a string for comparing an option's argument 136 * 137 * This call is similar to hwconfig_arg, but instead of returning 138 * hwconfig argument and its length, it is comparing it to @arg. 139 * 140 * Returns non-zero value if @arg matches, 0 otherwise. 141 * 142 * If CONFIG_HWCONFIG is undefined, the function returns a non-zero 143 * value, i.e. the argument matches. 144 */ 145 int hwconfig_arg_cmp(const char *opt, const char *arg) 146 { 147 const char *argstr; 148 size_t arglen; 149 150 argstr = hwconfig_arg(opt, &arglen); 151 if (!argstr || arglen != strlen(arg)) 152 return 0; 153 154 return !strncmp(argstr, arg, arglen); 155 } 156 157 /* 158 * hwconfig_sub - query if a particular hwconfig sub-option is specified 159 * @opt: a string representing an option 160 * @subopt: a string representing a sub-option 161 * 162 * This call is similar to hwconfig(), except that it takes additional 163 * argument @subopt. In this example: 164 * "dr_usb:mode=peripheral" 165 * "dr_usb" is an option, "mode" is a sub-option, and "peripheral" is its 166 * argument. 167 */ 168 int hwconfig_sub(const char *opt, const char *subopt) 169 { 170 size_t arglen; 171 const char *arg; 172 173 arg = __hwconfig(opt, &arglen); 174 if (!arg) 175 return 0; 176 return !!hwconfig_parse(arg, arglen, subopt, ",;", '=', NULL); 177 } 178 179 /* 180 * hwconfig_subarg - get hwconfig sub-option's argument 181 * @opt: a string representing an option 182 * @subopt: a string representing a sub-option 183 * @subarglen: a pointer to an allocated size_t variable 184 * 185 * This call is similar to hwconfig_arg(), except that it takes an additional 186 * argument @subopt, and so works with sub-options. 187 */ 188 const char *hwconfig_subarg(const char *opt, const char *subopt, 189 size_t *subarglen) 190 { 191 size_t arglen; 192 const char *arg; 193 194 arg = __hwconfig(opt, &arglen); 195 if (!arg) 196 return NULL; 197 return hwconfig_parse(arg, arglen, subopt, ",;", '=', subarglen); 198 } 199 200 /* 201 * hwconfig_arg_cmp - compare hwconfig sub-option's argument 202 * @opt: a string representing an option 203 * @subopt: a string representing a sub-option 204 * @subarg: a string for comparing an sub-option's argument 205 * 206 * This call is similar to hwconfig_arg_cmp, except that it takes an additional 207 * argument @subopt, and so works with sub-options. 208 */ 209 int hwconfig_subarg_cmp(const char *opt, const char *subopt, const char *subarg) 210 { 211 const char *argstr; 212 size_t arglen; 213 214 argstr = hwconfig_subarg(opt, subopt, &arglen); 215 if (!argstr || arglen != strlen(subarg)) 216 return 0; 217 218 return !strncmp(argstr, subarg, arglen); 219 } 220 221 #ifdef HWCONFIG_TEST 222 int main() 223 { 224 const char *ret; 225 size_t len; 226 227 setenv("hwconfig", "key1:subkey1=value1,subkey2=value2;key2:value3;;;;" 228 "key3;:,:=;key4", 1); 229 230 ret = hwconfig_arg("key1", &len); 231 printf("%zd %.*s\n", len, (int)len, ret); 232 assert(len == 29); 233 assert(hwconfig_arg_cmp("key1", "subkey1=value1,subkey2=value2")); 234 assert(!strncmp(ret, "subkey1=value1,subkey2=value2", len)); 235 236 ret = hwconfig_subarg("key1", "subkey1", &len); 237 printf("%zd %.*s\n", len, (int)len, ret); 238 assert(len == 6); 239 assert(hwconfig_subarg_cmp("key1", "subkey1", "value1")); 240 assert(!strncmp(ret, "value1", len)); 241 242 ret = hwconfig_subarg("key1", "subkey2", &len); 243 printf("%zd %.*s\n", len, (int)len, ret); 244 assert(len == 6); 245 assert(hwconfig_subarg_cmp("key1", "subkey2", "value2")); 246 assert(!strncmp(ret, "value2", len)); 247 248 ret = hwconfig_arg("key2", &len); 249 printf("%zd %.*s\n", len, (int)len, ret); 250 assert(len == 6); 251 assert(hwconfig_arg_cmp("key2", "value3")); 252 assert(!strncmp(ret, "value3", len)); 253 254 assert(hwconfig("key3")); 255 assert(hwconfig_arg("key4", &len) == NULL); 256 assert(hwconfig_arg("bogus", &len) == NULL); 257 258 unsetenv("hwconfig"); 259 260 assert(hwconfig(NULL) == 0); 261 assert(hwconfig("") == 0); 262 assert(hwconfig("key3") == 0); 263 264 return 0; 265 } 266 #endif /* HWCONFIG_TEST */ 267