/* This call is similar to hwconfig_f(), 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_f(const char *opt, const char *subopt, char *buf)
/* This call is similar to hwconfig_f(), 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_f(const char *opt, const char *subopt, char *buf)
{
	size_t arglen;
	const char *arg;
	arg = __hwconfig(opt, &arglen, buf);
	if (!arg)
		return 0;
	return !!hwconfig_parse(arg, arglen, subopt, ",;", '=', NULL);
}