/* * An inteface for configuring a hardware via u-boot environment. * * Copyright (c) 2009 MontaVista Software, Inc. * * Author: Anton Vorontsov <avorontsov@ru.mvista.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. */ #include <config.h> #include <common.h> #include <exports.h> #include <hwconfig.h> #include <linux/types.h> #include <linux/string.h> static const char *hwconfig_parse(const char *opts, size_t maxlen, const char *opt, char stopch, 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 || str[-1] == stopch) && (*end == stopch || *end == eqch || *end == '\0')) { const char *arg_end; if (!arglen) return str; if (*end != eqch) return NULL; arg_end = strchr(str, stopch); 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 = getenv("hwconfig"); if (env_hwconfig) return hwconfig_parse(env_hwconfig, strlen(env_hwconfig), opt, ';', ':', arglen); if (board_hwconfig) return hwconfig_parse(board_hwconfig, strlen(board_hwconfig), opt, ';', ':', arglen); if (cpu_hwconfig) return hwconfig_parse(cpu_hwconfig, strlen(cpu_hwconfig), opt, ';', ':', arglen); return NULL; } /* * hwconfig - query if a particular hwconfig option is specified * @opt: a string representing an option * * 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(const char *opt) { return !!__hwconfig(opt, NULL); } /* * hwconfig_arg - get hwconfig option's argument * @opt: a string representing an option * @arglen: a pointer to an allocated size_t variable * * Unlike hwconfig() 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(const char *opt, size_t *arglen) { return __hwconfig(opt, arglen); } /* * hwconfig_arg_cmp - compare hwconfig option's argument * @opt: a string representing an option * @arg: a string for comparing an option's argument * * This call is similar to hwconfig_arg, 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(const char *opt, const char *arg) { const char *argstr; size_t arglen; argstr = hwconfig_arg(opt, &arglen); if (!argstr || arglen != strlen(arg)) return 0; return !strncmp(argstr, arg, arglen); } /* * hwconfig_sub - query if a particular hwconfig sub-option is specified * @opt: a string representing an option * @subopt: a string representing a sub-option * * This call is similar to hwconfig(), 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(const char *opt, const char *subopt) { size_t arglen; const char *arg; arg = __hwconfig(opt, &arglen); if (!arg) return 0; return !!hwconfig_parse(arg, arglen, subopt, ',', '=', NULL); } /* * hwconfig_subarg - 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 * * This call is similar to hwconfig_arg(), except that it takes an additional * argument @subopt, and so works with sub-options. */ const char *hwconfig_subarg(const char *opt, const char *subopt, size_t *subarglen) { size_t arglen; const char *arg; arg = __hwconfig(opt, &arglen); if (!arg) return NULL; return hwconfig_parse(arg, arglen, subopt, ',', '=', subarglen); } /* * hwconfig_arg_cmp - 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 * * This call is similar to hwconfig_arg_cmp, except that it takes an additional * argument @subopt, and so works with sub-options. */ int hwconfig_subarg_cmp(const char *opt, const char *subopt, const char *subarg) { const char *argstr; size_t arglen; argstr = hwconfig_subarg(opt, subopt, &arglen); if (!argstr || arglen != strlen(subarg)) return 0; return !strncmp(argstr, subarg, arglen); }