1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * An inteface for configuring a hardware via u-boot environment. 4 * 5 * Copyright (c) 2009 MontaVista Software, Inc. 6 * Copyright 2011 Freescale Semiconductor, Inc. 7 * 8 * Author: Anton Vorontsov <avorontsov (at) ru.mvista.com> 9 */ 10 11 #ifndef HWCONFIG_TEST 12 #include <config.h> 13 #include <common.h> 14 #include <exports.h> 15 #include <hwconfig.h> 16 #include <linux/types.h> 17 #include <linux/string.h> 18 #else 19 #include <stdio.h> 20 #include <stdlib.h> 21 #include <string.h> 22 #include <assert.h> 23 #define min(a, b) (((a) < (b)) ? (a) : (b)) 24 #endif /* HWCONFIG_TEST */ 25 26 DECLARE_GLOBAL_DATA_PTR; 27 28 static const char *hwconfig_parse(const char *opts, size_t maxlen, 29 const char *opt, char *stopchs, char eqch, 30 size_t *arglen) 31 { 32 size_t optlen = strlen(opt); 33 char *str; 34 const char *start = opts; 35 const char *end; 36 37 next: 38 str = strstr(opts, opt); 39 end = str + optlen; 40 if (end - start > maxlen) 41 return NULL; 42 43 if (str && (str == opts || strpbrk(str - 1, stopchs) == str - 1) && 44 (strpbrk(end, stopchs) == end || *end == eqch || 45 *end == '\0')) { 46 const char *arg_end; 47 48 if (!arglen) 49 return str; 50 51 if (*end != eqch) 52 return NULL; 53 54 arg_end = strpbrk(str, stopchs); 55 if (!arg_end) 56 *arglen = min(maxlen, strlen(str)) - optlen - 1; 57 else 58 *arglen = arg_end - end - 1; 59 60 return end + 1; 61 } else if (str) { 62 opts = end; 63 goto next; 64 } 65 return NULL; 66 } 67 68 const char cpu_hwconfig[] __attribute__((weak)) = ""; 69 const char board_hwconfig[] __attribute__((weak)) = ""; 70 71 static const char *__hwconfig(const char *opt, size_t *arglen, 72 const char *env_hwconfig) 73 { 74 const char *ret; 75 76 /* if we are passed a buffer use it, otherwise try the environment */ 77 if (!env_hwconfig) { 78 if (!(gd->flags & GD_FLG_ENV_READY)) { 79 printf("WARNING: Calling __hwconfig without a buffer " 80 "and before environment is ready\n"); 81 return NULL; 82 } 83 env_hwconfig = env_get("hwconfig"); 84 } 85 86 if (env_hwconfig) { 87 ret = hwconfig_parse(env_hwconfig, strlen(env_hwconfig), 88 opt, ";", ':', arglen); 89 if (ret) 90 return ret; 91 } 92 93 ret = hwconfig_parse(board_hwconfig, strlen(board_hwconfig), 94 opt, ";", ':', arglen); 95 if (ret) 96 return ret; 97 98 return hwconfig_parse(cpu_hwconfig, strlen(cpu_hwconfig), 99 opt, ";", ':', arglen); 100 } 101 102 /* 103 * hwconfig_f - query if a particular hwconfig option is specified 104 * @opt: a string representing an option 105 * @buf: if non-NULL use this buffer to parse, otherwise try env 106 * 107 * This call can be used to find out whether U-Boot should configure 108 * a particular hardware option. 109 * 110 * Returns non-zero value if the hardware option can be used and thus 111 * should be configured, 0 otherwise. 112 * 113 * This function also returns non-zero value if CONFIG_HWCONFIG is 114 * undefined. 115 * 116 * Returning non-zero value without CONFIG_HWCONFIG has its crucial 117 * purpose: the hwconfig() call should be a "transparent" interface, 118 * e.g. if a board doesn't need hwconfig facility, then we assume 119 * that the board file only calls things that are actually used, so 120 * hwconfig() will always return true result. 121 */ 122 int hwconfig_f(const char *opt, char *buf) 123 { 124 return !!__hwconfig(opt, NULL, buf); 125 } 126 127 /* 128 * hwconfig_arg_f - get hwconfig option's argument 129 * @opt: a string representing an option 130 * @arglen: a pointer to an allocated size_t variable 131 * @buf: if non-NULL use this buffer to parse, otherwise try env 132 * 133 * Unlike hwconfig_f() function, this function returns a pointer to the 134 * start of the hwconfig arguments, if option is not found or it has 135 * no specified arguments, the function returns NULL pointer. 136 * 137 * If CONFIG_HWCONFIG is undefined, the function returns "", and 138 * arglen is set to 0. 139 */ 140 const char *hwconfig_arg_f(const char *opt, size_t *arglen, char *buf) 141 { 142 return __hwconfig(opt, arglen, buf); 143 } 144 145 /* 146 * hwconfig_arg_cmp_f - compare hwconfig option's argument 147 * @opt: a string representing an option 148 * @arg: a string for comparing an option's argument 149 * @buf: if non-NULL use this buffer to parse, otherwise try env 150 * 151 * This call is similar to hwconfig_arg_f, but instead of returning 152 * hwconfig argument and its length, it is comparing it to @arg. 153 * 154 * Returns non-zero value if @arg matches, 0 otherwise. 155 * 156 * If CONFIG_HWCONFIG is undefined, the function returns a non-zero 157 * value, i.e. the argument matches. 158 */ 159 int hwconfig_arg_cmp_f(const char *opt, const char *arg, char *buf) 160 { 161 const char *argstr; 162 size_t arglen; 163 164 argstr = hwconfig_arg_f(opt, &arglen, buf); 165 if (!argstr || arglen != strlen(arg)) 166 return 0; 167 168 return !strncmp(argstr, arg, arglen); 169 } 170 171 /* 172 * hwconfig_sub_f - query if a particular hwconfig sub-option is specified 173 * @opt: a string representing an option 174 * @subopt: a string representing a sub-option 175 * @buf: if non-NULL use this buffer to parse, otherwise try env 176 * 177 * This call is similar to hwconfig_f(), except that it takes additional 178 * argument @subopt. In this example: 179 * "dr_usb:mode=peripheral" 180 * "dr_usb" is an option, "mode" is a sub-option, and "peripheral" is its 181 * argument. 182 */ 183 int hwconfig_sub_f(const char *opt, const char *subopt, char *buf) 184 { 185 size_t arglen; 186 const char *arg; 187 188 arg = __hwconfig(opt, &arglen, buf); 189 if (!arg) 190 return 0; 191 return !!hwconfig_parse(arg, arglen, subopt, ",;", '=', NULL); 192 } 193 194 /* 195 * hwconfig_subarg_f - get hwconfig sub-option's argument 196 * @opt: a string representing an option 197 * @subopt: a string representing a sub-option 198 * @subarglen: a pointer to an allocated size_t variable 199 * @buf: if non-NULL use this buffer to parse, otherwise try env 200 * 201 * This call is similar to hwconfig_arg_f(), except that it takes an 202 * additional argument @subopt, and so works with sub-options. 203 */ 204 const char *hwconfig_subarg_f(const char *opt, const char *subopt, 205 size_t *subarglen, char *buf) 206 { 207 size_t arglen; 208 const char *arg; 209 210 arg = __hwconfig(opt, &arglen, buf); 211 if (!arg) 212 return NULL; 213 return hwconfig_parse(arg, arglen, subopt, ",;", '=', subarglen); 214 } 215 216 /* 217 * hwconfig_arg_cmp_f - compare hwconfig sub-option's argument 218 * @opt: a string representing an option 219 * @subopt: a string representing a sub-option 220 * @subarg: a string for comparing an sub-option's argument 221 * @buf: if non-NULL use this buffer to parse, otherwise try env 222 * 223 * This call is similar to hwconfig_arg_cmp_f, except that it takes an 224 * additional argument @subopt, and so works with sub-options. 225 */ 226 int hwconfig_subarg_cmp_f(const char *opt, const char *subopt, 227 const char *subarg, char *buf) 228 { 229 const char *argstr; 230 size_t arglen; 231 232 argstr = hwconfig_subarg_f(opt, subopt, &arglen, buf); 233 if (!argstr || arglen != strlen(subarg)) 234 return 0; 235 236 return !strncmp(argstr, subarg, arglen); 237 } 238 239 #ifdef HWCONFIG_TEST 240 int main() 241 { 242 const char *ret; 243 size_t len; 244 245 env_set("hwconfig", "key1:subkey1=value1,subkey2=value2;key2:value3;;;;" 246 "key3;:,:=;key4", 1); 247 248 ret = hwconfig_arg("key1", &len); 249 printf("%zd %.*s\n", len, (int)len, ret); 250 assert(len == 29); 251 assert(hwconfig_arg_cmp("key1", "subkey1=value1,subkey2=value2")); 252 assert(!strncmp(ret, "subkey1=value1,subkey2=value2", len)); 253 254 ret = hwconfig_subarg("key1", "subkey1", &len); 255 printf("%zd %.*s\n", len, (int)len, ret); 256 assert(len == 6); 257 assert(hwconfig_subarg_cmp("key1", "subkey1", "value1")); 258 assert(!strncmp(ret, "value1", len)); 259 260 ret = hwconfig_subarg("key1", "subkey2", &len); 261 printf("%zd %.*s\n", len, (int)len, ret); 262 assert(len == 6); 263 assert(hwconfig_subarg_cmp("key1", "subkey2", "value2")); 264 assert(!strncmp(ret, "value2", len)); 265 266 ret = hwconfig_arg("key2", &len); 267 printf("%zd %.*s\n", len, (int)len, ret); 268 assert(len == 6); 269 assert(hwconfig_arg_cmp("key2", "value3")); 270 assert(!strncmp(ret, "value3", len)); 271 272 assert(hwconfig("key3")); 273 assert(hwconfig_arg("key4", &len) == NULL); 274 assert(hwconfig_arg("bogus", &len) == NULL); 275 276 unenv_set("hwconfig"); 277 278 assert(hwconfig(NULL) == 0); 279 assert(hwconfig("") == 0); 280 assert(hwconfig("key3") == 0); 281 282 return 0; 283 } 284 #endif /* HWCONFIG_TEST */ 285
