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 * SPDX-License-Identifier: GPL-2.0+ 10 */ 11 12 #ifndef HWCONFIG_TEST 13 #include <config.h> 14 #include <common.h> 15 #include <exports.h> 16 #include <hwconfig.h> 17 #include <linux/types.h> 18 #include <linux/string.h> 19 #else 20 #include <stdio.h> 21 #include <stdlib.h> 22 #include <string.h> 23 #include <assert.h> 24 #define min(a, b) (((a) < (b)) ? (a) : (b)) 25 #endif /* HWCONFIG_TEST */ 26 27 DECLARE_GLOBAL_DATA_PTR; 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 const char *env_hwconfig) 74 { 75 const char *ret; 76 77 /* if we are passed a buffer use it, otherwise try the environment */ 78 if (!env_hwconfig) { 79 if (!(gd->flags & GD_FLG_ENV_READY)) { 80 printf("WARNING: Calling __hwconfig without a buffer " 81 "and before environment is ready\n"); 82 return NULL; 83 } 84 env_hwconfig = getenv("hwconfig"); 85 } 86 87 if (env_hwconfig) { 88 ret = hwconfig_parse(env_hwconfig, strlen(env_hwconfig), 89 opt, ";", ':', arglen); 90 if (ret) 91 return ret; 92 } 93 94 ret = hwconfig_parse(board_hwconfig, strlen(board_hwconfig), 95 opt, ";", ':', arglen); 96 if (ret) 97 return ret; 98 99 return hwconfig_parse(cpu_hwconfig, strlen(cpu_hwconfig), 100 opt, ";", ':', arglen); 101 } 102 103 /* 104 * hwconfig_f - query if a particular hwconfig option is specified 105 * @opt: a string representing an option 106 * @buf: if non-NULL use this buffer to parse, otherwise try env 107 * 108 * This call can be used to find out whether U-Boot should configure 109 * a particular hardware option. 110 * 111 * Returns non-zero value if the hardware option can be used and thus 112 * should be configured, 0 otherwise. 113 * 114 * This function also returns non-zero value if CONFIG_HWCONFIG is 115 * undefined. 116 * 117 * Returning non-zero value without CONFIG_HWCONFIG has its crucial 118 * purpose: the hwconfig() call should be a "transparent" interface, 119 * e.g. if a board doesn't need hwconfig facility, then we assume 120 * that the board file only calls things that are actually used, so 121 * hwconfig() will always return true result. 122 */ 123 int hwconfig_f(const char *opt, char *buf) 124 { 125 return !!__hwconfig(opt, NULL, buf); 126 } 127 128 /* 129 * hwconfig_arg_f - get hwconfig option's argument 130 * @opt: a string representing an option 131 * @arglen: a pointer to an allocated size_t variable 132 * @buf: if non-NULL use this buffer to parse, otherwise try env 133 * 134 * Unlike hwconfig_f() function, this function returns a pointer to the 135 * start of the hwconfig arguments, if option is not found or it has 136 * no specified arguments, the function returns NULL pointer. 137 * 138 * If CONFIG_HWCONFIG is undefined, the function returns "", and 139 * arglen is set to 0. 140 */ 141 const char *hwconfig_arg_f(const char *opt, size_t *arglen, char *buf) 142 { 143 return __hwconfig(opt, arglen, buf); 144 } 145 146 /* 147 * hwconfig_arg_cmp_f - compare hwconfig option's argument 148 * @opt: a string representing an option 149 * @arg: a string for comparing an option's argument 150 * @buf: if non-NULL use this buffer to parse, otherwise try env 151 * 152 * This call is similar to hwconfig_arg_f, but instead of returning 153 * hwconfig argument and its length, it is comparing it to @arg. 154 * 155 * Returns non-zero value if @arg matches, 0 otherwise. 156 * 157 * If CONFIG_HWCONFIG is undefined, the function returns a non-zero 158 * value, i.e. the argument matches. 159 */ 160 int hwconfig_arg_cmp_f(const char *opt, const char *arg, char *buf) 161 { 162 const char *argstr; 163 size_t arglen; 164 165 argstr = hwconfig_arg_f(opt, &arglen, buf); 166 if (!argstr || arglen != strlen(arg)) 167 return 0; 168 169 return !strncmp(argstr, arg, arglen); 170 } 171 172 /* 173 * hwconfig_sub_f - query if a particular hwconfig sub-option is specified 174 * @opt: a string representing an option 175 * @subopt: a string representing a sub-option 176 * @buf: if non-NULL use this buffer to parse, otherwise try env 177 * 178 * This call is similar to hwconfig_f(), except that it takes additional 179 * argument @subopt. In this example: 180 * "dr_usb:mode=peripheral" 181 * "dr_usb" is an option, "mode" is a sub-option, and "peripheral" is its 182 * argument. 183 */ 184 int hwconfig_sub_f(const char *opt, const char *subopt, char *buf) 185 { 186 size_t arglen; 187 const char *arg; 188 189 arg = __hwconfig(opt, &arglen, buf); 190 if (!arg) 191 return 0; 192 return !!hwconfig_parse(arg, arglen, subopt, ",;", '=', NULL); 193 } 194 195 /* 196 * hwconfig_subarg_f - get hwconfig sub-option's argument 197 * @opt: a string representing an option 198 * @subopt: a string representing a sub-option 199 * @subarglen: a pointer to an allocated size_t variable 200 * @buf: if non-NULL use this buffer to parse, otherwise try env 201 * 202 * This call is similar to hwconfig_arg_f(), except that it takes an 203 * additional argument @subopt, and so works with sub-options. 204 */ 205 const char *hwconfig_subarg_f(const char *opt, const char *subopt, 206 size_t *subarglen, char *buf) 207 { 208 size_t arglen; 209 const char *arg; 210 211 arg = __hwconfig(opt, &arglen, buf); 212 if (!arg) 213 return NULL; 214 return hwconfig_parse(arg, arglen, subopt, ",;", '=', subarglen); 215 } 216 217 /* 218 * hwconfig_arg_cmp_f - compare hwconfig sub-option's argument 219 * @opt: a string representing an option 220 * @subopt: a string representing a sub-option 221 * @subarg: a string for comparing an sub-option's argument 222 * @buf: if non-NULL use this buffer to parse, otherwise try env 223 * 224 * This call is similar to hwconfig_arg_cmp_f, except that it takes an 225 * additional argument @subopt, and so works with sub-options. 226 */ 227 int hwconfig_subarg_cmp_f(const char *opt, const char *subopt, 228 const char *subarg, char *buf) 229 { 230 const char *argstr; 231 size_t arglen; 232 233 argstr = hwconfig_subarg_f(opt, subopt, &arglen, buf); 234 if (!argstr || arglen != strlen(subarg)) 235 return 0; 236 237 return !strncmp(argstr, subarg, arglen); 238 } 239 240 #ifdef HWCONFIG_TEST 241 int 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 */ 286